Patent application number | Description | Published |
20100102311 | OXIDE SEMICONDUCTOR, THIN FILM TRANSISTOR, AND DISPLAY DEVICE - An object is to control composition and a defect of an oxide semiconductor, another object is to increase a field effect mobility of a thin film transistor and to obtain a sufficient on-off ratio with a reduced off current. A solution is to employ an oxide semiconductor whose composition is represented by InMO | 04-29-2010 |
20100102312 | OXIDE SEMICONDUCTOR, THIN FILM TRANSISTOR, AND DISPLAY DEVICE - An object is to control composition and a defect of an oxide semiconductor. Another object is to increase field effect mobility of a thin film transistor and to obtain a sufficient on-off ratio with off current suppressed. The oxide semiconductor is represented by InMO | 04-29-2010 |
20100109003 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to improve field effect mobility of a thin film transistor using an oxide semiconductor. Another object is to suppress increase in off current even in a thin film transistor with improved field effect mobility. In a thin film transistor using an oxide semiconductor layer, by forming a semiconductor layer having higher electrical conductivity and a smaller thickness than the oxide semiconductor layer between the oxide semiconductor layer and a gate insulating layer, field effect mobility of the thin film transistor can be improved, and increase in off current can be suppressed. | 05-06-2010 |
20100117078 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to increase field effect mobility of a thin film transistor including an oxide semiconductor. Another object is to stabilize electrical characteristics of the thin film transistor. In a thin film transistor including an oxide semiconductor layer, a semiconductor layer or a conductive layer having higher electrical conductivity than the oxide semiconductor is formed over the oxide semiconductor layer, whereby field effect mobility of the thin film transistor can be increased. Further, by forming a semiconductor layer or a conductive layer having higher electrical conductivity than the oxide semiconductor between the oxide semiconductor layer and a protective insulating layer of the thin film transistor, change in composition or deterioration in film quality of the oxide semiconductor layer is prevented, so that electrical characteristics of the thin film transistor can be stabilized. | 05-13-2010 |
20100133530 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is, in a thin film transistor in which an oxide semiconductor is used as an active layer, to prevent change in composition, film quality, an interface, or the like of an oxide semiconductor region serving as an active layer, and to stabilize electrical characteristics of the thin film transistor. In a thin film transistor in which a first oxide semiconductor region is used as an active layer, a second oxide semiconductor region having lower electrical conductivity than the first oxide semiconductor region is formed between the first oxide semiconductor region and a protective insulating layer for the thin film transistor, whereby the second oxide semiconductor region serves as a protective layer for the first oxide semiconductor region; thus, change in composition or deterioration in film quality of the first oxide semiconductor region can be prevented, and electrical characteristics of the thin film transistor can be stabilized. | 06-03-2010 |
20100133531 | SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF - A gate electrode layer over a substrate; a gate insulating layer over the gate electrode layer; a first source electrode layer and a first drain electrode layer over the gate insulating layer; an oxide semiconductor layer over the gate insulating layer; and a second source electrode layer and a second drain electrode layer over the oxide semiconductor layer. A first part, a second part, and a third part of a bottom surface are in contact with the first source electrode layer, the first drain electrode layer, and the gate insulating layer respectively. A first part and a second part of the top surface are in contact with the second source electrode layer and the second drain electrode layer respectively. The first source electrode layer and the first drain electrode layer are electrically connected to the second source electrode layer and the second drain electrode layer respectively. | 06-03-2010 |
20100181565 | SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF - A semiconductor device including a thin film transistor which includes an oxide semiconductor layer and has high electric characteristics and reliability. Film deposition is performed using an oxide semiconductor target containing an insulator (an insulating oxide, an insulating nitride, silicon oxynitride, aluminum oxynitride, or the like), typically SiO | 07-22-2010 |
20100187523 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to provide a semiconductor device including a thin film transistor which includes an oxide semiconductor layer and has high electric characteristics. An oxide semiconductor layer including SiO | 07-29-2010 |
20100233847 | METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - An object is to provide a semiconductor device including a semiconductor element which has favorable characteristics. A manufacturing method of the present invention includes the steps of: forming a first conductive layer which functions as a gate electrode over a substrate; forming a first insulating layer to cover the first conductive layer; forming a semiconductor layer over the first insulating layer so that part of the semiconductor layer overlaps with the first conductive layer; forming a second conductive layer to be electrically connected to the semiconductor layer; forming a second insulating layer to cover the semiconductor layer and the second conductive layer; forming a third conductive layer to be electrically connected to the second conductive layer; performing first heat treatment after forming the semiconductor layer and before forming the second insulating layer; and performing second heat treatment after forming the second insulating layer. | 09-16-2010 |
20100233848 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SEMICONDUCTOR DEVICE - If an oxide semiconductor layer is crystallized by heat treatment without being covered with an inorganic insulating film, surface unevenness and the like are formed due to the crystallization, which may cause variation in electrical characteristics. Steps are performed in the following order: a second insulating film is formed on an oxide semiconductor layer over a substrate and then heat treatment is performed, instead of performing heat treatment during a period immediately after formation of the oxide semiconductor layer and immediately before formation of an inorganic insulating film including silicon oxide on the oxide semiconductor layer. The density of hydrogen included in the inorganic insulating film including silicon oxide is 5×10 | 09-16-2010 |
20100244020 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object of an embodiment of the present invention is to provide a semiconductor device provided with a thin film transistor which includes an oxide semiconductor layer and has high electric characteristics. The semiconductor device includes a gate electrode over an insulating surface, an oxide semiconductor layer including silicon oxide, an insulating layer between the gate electrode and the oxide semiconductor layer, and source and drain regions between the oxide semiconductor layer including silicon oxide and source and drain electrode layers. The source and drain regions are formed using a degenerate oxide semiconductor material or a degenerate oxynitride material. | 09-30-2010 |
20100304529 | SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF - An object is to provide a highly reliable semiconductor device including a thin film transistor having stable electric characteristics. In addition, another object is to manufacture a highly reliable semiconductor device at low cost with high productivity. In a method for manufacturing a semiconductor device including a thin film transistor including an oxide semiconductor layer as a channel formation region, the oxide semiconductor layer is heated under a nitrogen atmosphere to lower its resistance, thereby forming a low-resistance oxide semiconductor layer. Further, resistance of a region of the low-resistance oxide semiconductor layer, which is overlapped with a gate electrode layer, is selectively increased, thereby forming a high-resistance oxide semiconductor layer. Resistance of the oxide semiconductor layer is increased by forming a silicon oxide film in contact with the oxide semiconductor layer by a sputtering method. | 12-02-2010 |
20110003418 | DISPLAY DEVICE INCLUDING TRANSISTOR AND MANUFACTURING METHOD THEREOF - An object is to provide a display device which operates stably with use of a transistor having stable electric characteristics. In manufacture of a display device using transistors in which an oxide semiconductor layer is used for a channel formation region, a gate electrode is further provided over at least a transistor which is applied to a driver circuit. In manufacture of a transistor in which an oxide semiconductor layer is used for a channel formation region, the oxide semiconductor layer is subjected to heat treatment so as to be dehydrated or dehydrogenated; thus, impurities such as moisture existing in an interface between the oxide semiconductor layer and the gate insulating layer provided below and in contact with the oxide semiconductor layer and an interface between the oxide semiconductor layer and a protective insulating layer provided on and in contact with the oxide semiconductor layer can be reduced. | 01-06-2011 |
20110003427 | METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - It is an object to provide a highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics. It is another object to manufacture a highly reliable semiconductor device at lower cost with high productivity. In a method for manufacturing a semiconductor device which includes a thin film transistor where a semiconductor layer including a channel formation region using an oxide semiconductor layer, a source region, and a drain region are formed using an oxide semiconductor layer, heat treatment for reducing impurities such as moisture (heat treatment for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor layer. | 01-06-2011 |
20110003428 | METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - It is an object to provide a highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics. It is another object to manufacture a highly reliable semiconductor device at lower cost with high productivity. In a method for manufacturing a semiconductor device which includes a thin film transistor where a semiconductor layer having a channel formation region, a source region, and a drain region are formed using an oxide semiconductor layer, heat treatment (heat treatment for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor layer and reduce impurities such as moisture. Moreover, the oxide semiconductor layer subjected to the heat treatment is slowly cooled under an oxygen atmosphere. | 01-06-2011 |
20110003430 | MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE - An object is to provide a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, impurities such as moisture existing in the gate insulating layer are reduced before formation of the oxide semiconductor film, and then heat treatment (heat treatment for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor film and reduce impurities such as moisture. After that, slow cooling is performed in an oxygen atmosphere. Besides impurities such as moisture existing in the gate insulating layer and the oxide semiconductor film, impurities such as moisture existing at interfaces between the oxide semiconductor film and upper and lower films provided in contact therewith are reduced. | 01-06-2011 |
20110006301 | SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THE SAME - An object is to manufacture and provide a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which a semiconductor layer including a channel formation region serves as an oxide semiconductor film, heat treatment for reducing impurities such as moisture (heat treatment for dehydration or dehydrogenation) is performed after an oxide insulating film serving as a protective film is formed in contact with an oxide semiconductor layer. Then, the impurities such as moisture, which exist not only in a source electrode layer, in a drain electrode layer, in a gate insulating layer, and in the oxide semiconductor layer but also at interfaces between the oxide semiconductor film and upper and lower films which are in contact with the oxide semiconductor layer, are reduced. | 01-13-2011 |
20110008930 | METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - An object is to manufacture a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (for dehydration or dehydrogenation) is performed to improve the purity of the oxide semiconductor film and reduce impurities including moisture or the like. After that, slow cooling is performed under an oxygen atmosphere. Besides impurities including moisture or the like exiting in the oxide semiconductor film, heat treatment causes reduction of impurities including moisture or the like exiting in a gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor and in contact therewith. | 01-13-2011 |
20110008931 | METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - A highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics, and a manufacturing method thereof. In the manufacturing method of the semiconductor device which includes a thin film transistor where a semiconductor layer including a channel formation region is an oxide semiconductor layer, heat treatment which reduces impurities such as moisture to improve the purity of the oxide semiconductor layer and oxidize the oxide semiconductor layer (heat treatment for dehydration or dehydrogenation) is performed. Not only impurities such as moisture in the oxide semiconductor layer but also those existing in a gate insulating layer are reduced, and impurities such as moisture existing in interfaces between the oxide semiconductor layer and films provided over and under and in contact with the oxide semiconductor layer are reduced. | 01-13-2011 |
20110024750 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to provide a semiconductor device having a structure with which parasitic capacitance between wirings can be sufficiently reduced. An oxide insulating layer serving as a channel protective layer is formed over part of an oxide semiconductor layer overlapping with a gate electrode layer. In the same step as formation of the oxide insulating layer, an oxide insulating layer covering a peripheral portion of the oxide semiconductor layer is formed. The oxide insulating layer which covers the peripheral portion of the oxide semiconductor layer is provided to increase the distance between the gate electrode layer and a wiring layer formed above or in the periphery of the gate electrode layer, whereby parasitic capacitance is reduced. | 02-03-2011 |
20110024751 | SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF - In a bottom-gate thin film transistor using the stack of the first oxide semiconductor layer and the second oxide semiconductor layer, an oxide insulating layer serving as a channel protective layer is formed over and in contact with part of the oxide semiconductor layer overlapping with a gate electrode layer. In the same step as formation of the insulating layer, an oxide insulating layer covering a peripheral portion (including a side surface) of the stack of the oxide semiconductor layers is formed. | 02-03-2011 |
20110053322 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to provide a high reliable semiconductor device including a thin film transistor having stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (which is for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor film and reduce impurities such as moisture. Besides impurities such as moisture existing in the oxide semiconductor film, heat treatment causes reduction of impurities such as moisture existing in the gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor film and are in contact with the oxide semiconductor film. | 03-03-2011 |
20110057186 | TRANSISTOR AND DISPLAY DEVICE - It is an object to manufacture a highly reliable display device using a thin film transistor having favorable electric characteristics and high reliability as a switching element. In a bottom gate thin film transistor including an amorphous oxide semiconductor, an oxide conductive layer having a crystal region is formed between an oxide semiconductor layer which has been dehydrated or dehydrogenated by heat treatment and each of a source electrode layer and a drain electrode layer which are formed using a metal material. Accordingly, contact resistance between the oxide semiconductor layer and each of the source electrode layer and the drain electrode layer can be reduced; thus, a thin film transistor having favorable electric characteristics and a highly reliable display device using the thin film transistor can be provided. | 03-10-2011 |
20110057918 | DISPLAY DEVICE AND ELECTRONIC DEVICE - A display device including a pixel having a memory. The pixel includes at least a display element, a capacitor, an inverter, and a switch. The switch is controlled with a signal held in the capacitor and a signal output from the inverter so that voltage is supplied to the display element. The inverter and the switch can be constituted by transistors with the same polarity. A semiconductor layer included in the pixel may be formed using a light-transmitting material. Moreover, a gate electrode, a drain electrode, and a capacitor electrode may be formed using a light-transmitting conductive layer. The pixel is formed using a light-transmitting material in such a manner, whereby the display device can be a transmissive display device while including a pixel having a memory. | 03-10-2011 |
20110278582 | METHOD FOR MANUFACTURING MICROCRYSTALLINE SEMICONDUCTOR FILM AND METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - A method for manufacturing a semiconductor device having favorable electric characteristics with high productivity is provided. A first microcrystalline semiconductor film is formed over an oxide insulating film under a first condition that mixed phase grains with high crystallinity are formed at a low particle density. After that, a second microcrystalline semiconductor film is stacked over the first microcrystalline semiconductor film under a second condition that a space between the mixed phase grains are filled by the crystal growth of the mixed phase grains of the first microcrystalline semiconductor film. | 11-17-2011 |
20110284839 | SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF - It is an object to provide a semiconductor device including an oxide semiconductor, which has stable electric characteristics and high reliability. An oxide semiconductor film serving as a channel formation region of a transistor is formed by a sputtering method at a temperature higher than 200° C., so that the number of water molecules eliminated from the oxide semiconductor film can be 0.5/nm | 11-24-2011 |
20110284844 | SEMICONDUCTOR DEVICE - An object of the present invention is to manufacture a semiconductor device where fluctuation in electrical characteristics is small and reliability is high in a transistor in which an oxide semiconductor is used. An insulating layer from which oxygen is released by heating is used as a base insulating layer of an oxide semiconductor layer which forms a channel. Oxygen is released from the base insulating layer, whereby oxygen deficiency in the oxide semiconductor layer and an interface state between the base insulating layer and the oxide semiconductor layer can be reduced. Thus, a semiconductor device where fluctuation in electrical characteristics is small and reliability is high can be manufactured. | 11-24-2011 |
20110284845 | SEMICONDUCTOR DEVICE - An insulating layer containing a silicon peroxide radical is used as an insulating layer in contact with an oxide semiconductor layer for forming a channel. Oxygen is released from the insulating layer, whereby oxygen deficiency in the oxide semiconductor layer and an interface state between the insulating layer and the oxide semiconductor layer can be reduced. Accordingly, a semiconductor device where reliability is high and variation in electric characteristics is small can be manufactured. | 11-24-2011 |
20110284846 | SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - Oxygen is released from the insulating layer, whereby oxygen deficiency in the oxide semiconductor layer and an interface state between the insulating layer and the oxide semiconductor layer can be reduced. Accordingly, a semiconductor device where reliability is high and variation in electric characteristics is small can be manufactured. | 11-24-2011 |
20110284847 | SEMICONDUCTOR DEVICE - Disclosed is a semiconductor device with a transistor in which an oxide semiconductor is used. An insulating layer on a back channel side of the oxide semiconductor layer has capacitance of lower than or equal to 1.5×10 | 11-24-2011 |
20110284854 | SEMICONDUCTOR DEVICE - In a transistor having a top-gate structure in which a gate electrode layer overlaps with an oxide semiconductor layer which forms a channel region with a gate insulating layer interposed therebetween, when a large amount of hydrogen is contained in the insulating layer, hydrogen is diffused into the oxide semiconductor layer because the insulating layer is in contact with the oxide semiconductor layer; thus, electric characteristics of the transistor are degraded. An object is to provide a semiconductor device having favorable electric characteristics. An insulating layer in which the concentration of hydrogen is less than 6×10 | 11-24-2011 |
20120018727 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An insulating layer which releases a large amount of oxygen is used as an insulating layer in contact with a channel region of an oxide semiconductor layer, and an insulating layer which releases a small amount of oxygen is used as an insulating layer in contact with a source region and a drain region of the oxide semiconductor layer. By releasing oxygen from the insulating layer which releases a large amount of oxygen, oxygen deficiency in the channel region and an interface state density between the insulating layer and the channel region can be reduced, so that a highly reliable semiconductor device having small variation in electrical characteristics can be manufactured. The source region and the drain region are provided in contact with the insulating layer which releases a small amount of oxygen, thereby suppressing the increase of the resistance of the source region and the drain region. | 01-26-2012 |
20120032172 | SEMICONDUCTOR DEVICE - A semiconductor device including the following components and a manufacturing method of the semiconductor device are provided. The semiconductor device includes a substrate; an oxide semiconductor layer over the substrate; a source electrode and a drain electrode whose end portion has a taper angle and whose upper end portion has a curved surface, the source electrode and the drain electrode being electrically connected to the oxide semiconductor layer; a gate insulating layer being in contact with a part of the oxide semiconductor layer and covering the oxide semiconductor layer, the source electrode, and the drain electrode; and a gate electrode overlapping with the oxide semiconductor layer and being over the gate insulating layer. | 02-09-2012 |
20120040495 | MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE - A transistor with superior electric characteristics is manufactured. An oxide insulating film is formed over a substrate, an oxide semiconductor film is formed over the oxide insulating film, heat treatment is then conducted at a temperature at which hydrogen contained in the oxide semiconductor film is desorbed and part of oxygen contained in the oxide insulating film is desorbed, then the heated oxide semiconductor film is etched into a predetermined shape to form an island-shaped oxide semiconductor film, a pair of electrodes is formed over the island-shaped oxide semiconductor film, a gate insulating film is formed over the pair of electrodes and the island-shaped oxide semiconductor film, and a gate electrode is formed over the gate insulating film. | 02-16-2012 |
20120058600 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to increase field effect mobility of a thin film transistor including an oxide semiconductor. Another object is to stabilize electrical characteristics of the thin film transistor. In a thin film transistor including an oxide semiconductor layer, a semiconductor layer or a conductive layer having higher electrical conductivity than the oxide semiconductor is formed over the oxide semiconductor layer, whereby field effect mobility of the thin film transistor can be increased. Further, by forming a semiconductor layer or a conductive layer having higher electrical conductivity than the oxide semiconductor between the oxide semiconductor layer and a protective insulating layer of the thin film transistor, change in composition or deterioration in film quality of the oxide semiconductor layer is prevented, so that electrical characteristics of the thin film transistor can be stabilized. | 03-08-2012 |
20120112183 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to provide a semiconductor device including an oxynitride semiconductor whose carrier density is controlled. By introducing controlled nitrogen into an oxide semiconductor layer, a transistor in which an oxynitride semiconductor having desired carrier density and on characteristics is used for a channel can be manufactured. Further, with the use of the oxynitride semiconductor, even when a low resistance layer or the like is not provided between an oxynitride semiconductor layer and a source electrode and between the oxynitride semiconductor layer and a drain electrode, favorable contact characteristics can be exhibited. | 05-10-2012 |
20120119212 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - A semiconductor device is manufactured using a transistor in which an oxide semiconductor is included in a channel region and variation in electric characteristics due to a short-channel effect is less likely to be caused. The semiconductor device includes an oxide semiconductor film having a pair of oxynitride semiconductor regions including nitrogen and an oxide semiconductor region sandwiched between the pair of oxynitride semiconductor regions, a gate insulating film, and a gate electrode provided over the oxide semiconductor region with the gate insulating film positioned therebetween. Here, the pair of oxynitride semiconductor regions serves as a source region and a drain region of the transistor, and the oxide semiconductor region serves as the channel region of the transistor. | 05-17-2012 |
20120153275 | SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF - To manufacture a transistor whose threshold voltage is controlled without using a backgate electrode, a circuit for controlling the threshold voltage, and an impurity introduction method. To manufacture a semiconductor device having favorable electrical characteristics, high reliability, and low power consumption using the transistor. A gate electrode including a tungsten oxide film whose composition is controlled is used. The composition or the like is adjusted by a film formation method of the tungsten oxide film, whereby the work function can be controlled. By using the tungsten oxide film whose work function is controlled as part of the gate electrode, the threshold of the transistor can be controlled. Using the transistor whose threshold voltage is controlled, a semiconductor device having favorable electrical characteristics, high reliability, and low power consumption can be manufactured. | 06-21-2012 |
20120244660 | METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - It is an object to provide a highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics. It is another object to manufacture a highly reliable semiconductor device at lower cost with high productivity. In a method for manufacturing a semiconductor device which includes a thin film transistor where a semiconductor layer having a channel formation region, a source region, and a drain region are formed using an oxide semiconductor layer, heat treatment (heat treatment for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor layer and reduce impurities such as moisture. Moreover, the oxide semiconductor layer subjected to the heat treatment is slowly cooled under an oxygen atmosphere. | 09-27-2012 |
20120264244 | METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - An object is to manufacture a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (for dehydration or dehydrogenation) is performed to improve the purity of the oxide semiconductor film and reduce impurities including moisture or the like. After that, slow cooling is performed under an oxygen atmosphere. Besides impurities including moisture or the like exiting in the oxide semiconductor film, heat treatment causes reduction of impurities including moisture or the like exiting in a gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor and in contact therewith. | 10-18-2012 |
20120319106 | SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THE SAME - An object is to manufacture and provide a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which a semiconductor layer including a channel formation region serves as an oxide semiconductor film, heat treatment for reducing impurities such as moisture (heat treatment for dehydration or dehydrogenation) is performed after an oxide insulating film serving as a protective film is formed in contact with an oxide semiconductor layer. Then, the impurities such as moisture, which exist not only in a source electrode layer, in a drain electrode layer, in a gate insulating layer, and in the oxide semiconductor layer but also at interfaces between the oxide semiconductor film and upper and lower films which are in contact with the oxide semiconductor layer, are reduced. | 12-20-2012 |
20130001545 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to increase field effect mobility of a thin film transistor including an oxide semiconductor. Another object is to stabilize electrical characteristics of the thin film transistor. In a thin film transistor including an oxide semiconductor layer, a semiconductor layer or a conductive layer having higher electrical conductivity than the oxide semiconductor is formed over the oxide semiconductor layer, whereby field effect mobility of the thin film transistor can be increased. Further, by forming a semiconductor layer or a conductive layer having higher electrical conductivity than the oxide semiconductor between the oxide semiconductor layer and a protective insulating layer of the thin film transistor, change in composition or deterioration in film quality of the oxide semiconductor layer is prevented, so that electrical characteristics of the thin film transistor can be stabilized. | 01-03-2013 |
20130037799 | DISPLAY DEVICE INCLUDING TRANSISTOR AND MANUFACTURING METHOD THEREOF - An object is to provide a display device which operates stably with use of a transistor having stable electric characteristics. In manufacture of a display device using transistors in which an oxide semiconductor layer is used for a channel formation region, a gate electrode is further provided over at least a transistor which is applied to a driver circuit. In manufacture of a transistor in which an oxide semiconductor layer is used for a channel formation region, the oxide semiconductor layer is subjected to heat treatment so as to be dehydrated or dehydrogenated; thus, impurities such as moisture existing in an interface between the oxide semiconductor layer and the gate insulating layer provided below and in contact with the oxide semiconductor layer and an interface between the oxide semiconductor layer and a protective insulating layer provided on and in contact with the oxide semiconductor layer can be reduced. | 02-14-2013 |
20130078762 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is, in a thin film transistor in which an oxide semiconductor is used as an active layer, to prevent change in composition, film quality, an interface, or the like of an oxide semiconductor region serving as an active layer, and to stabilize electrical characteristics of the thin film transistor. In a thin film transistor in which a first oxide semiconductor region is used as an active layer, a second oxide semiconductor region having lower electrical conductivity than the first oxide semiconductor region is formed between the first oxide semiconductor region and a protective insulating layer for the thin film transistor, whereby the second oxide semiconductor region serves as a protective layer for the first oxide semiconductor region; thus, change in composition or deterioration in film quality of the first oxide semiconductor region can be prevented, and electrical characteristics of the thin film transistor can be stabilized. | 03-28-2013 |
20130082255 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is, in a thin film transistor in which an oxide semiconductor is used as an active layer, to prevent change in composition, film quality, an interface, or the like of an oxide semiconductor region serving as an active layer, and to stabilize electrical characteristics of the thin film transistor. In a thin film transistor in which a first oxide semiconductor region is used as an active layer, a second oxide semiconductor region having lower electrical conductivity than the first oxide semiconductor region is formed between the first oxide semiconductor region and a protective insulating layer for the thin film transistor, whereby the second oxide semiconductor region serves as a protective layer for the first oxide semiconductor region; thus, change in composition or deterioration in film quality of the first oxide semiconductor region can be prevented, and electrical characteristics of the thin film transistor can be stabilized. | 04-04-2013 |
20130087785 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to improve field effect mobility of a thin film transistor using an oxide semiconductor. Another object is to suppress increase in off current even in a thin film transistor with improved field effect mobility. In a thin film transistor using an oxide semiconductor layer, by forming a semiconductor layer having higher electrical conductivity and a smaller thickness than the oxide semiconductor layer between the oxide semiconductor layer and a gate insulating layer, field effect mobility of the thin film transistor can be improved, and increase in off current can be suppressed. | 04-11-2013 |
20130089950 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to improve field effect mobility of a thin film transistor using an oxide semiconductor. Another object is to suppress increase in off current even in a thin film transistor with improved field effect mobility. In a thin film transistor using an oxide semiconductor layer, by forming a semiconductor layer having higher electrical conductivity and a smaller thickness than the oxide semiconductor layer between the oxide semiconductor layer and a gate insulating layer, field effect mobility of the thin film transistor can be improved, and increase in off current can be suppressed. | 04-11-2013 |
20130140559 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to provide a semiconductor device having a structure with which parasitic capacitance between wirings can be sufficiently reduced. An oxide insulating layer serving as a channel protective layer is formed over part of an oxide semiconductor layer overlapping with a gate electrode layer. In the same step as formation of the oxide insulating layer, an oxide insulating layer covering a peripheral portion of the oxide semiconductor layer is formed. The oxide insulating layer which covers the peripheral portion of the oxide semiconductor layer is provided to increase the distance between the gate electrode layer and a wiring layer formed above or in the periphery of the gate electrode layer, whereby parasitic capacitance is reduced. | 06-06-2013 |
20130149813 | SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THE SAME - An object is to manufacture and provide a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which a semiconductor layer including a channel formation region serves as an oxide semiconductor film, heat treatment for reducing impurities such as moisture (heat treatment for dehydration or dehydrogenation) is performed after an oxide insulating film serving as a protective film is formed in contact with an oxide semiconductor layer. Then, the impurities such as moisture, which exist not only in a source electrode layer, in a drain electrode layer, in a gate insulating layer, and in the oxide semiconductor layer but also at interfaces between the oxide semiconductor film and upper and lower films which are in contact with the oxide semiconductor layer, are reduced. | 06-13-2013 |
20130153910 | TRANSISTOR AND DISPLAY DEVICE - It is an object to manufacture a highly reliable display device using a thin film transistor having favorable electric characteristics and high reliability as a switching element. In a bottom gate thin film transistor including an amorphous oxide semiconductor, an oxide conductive layer having a crystal region is formed between an oxide semiconductor layer which has been dehydrated or dehydrogenated by heat treatment and each of a source electrode layer and a drain electrode layer which are formed using a metal material. Accordingly, contact resistance between the oxide semiconductor layer and each of the source electrode layer and the drain electrode layer can be reduced; thus, a thin film transistor having favorable electric characteristics and a highly reliable display device using the thin film transistor can be provided. | 06-20-2013 |
20130157411 | METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - It is an object to provide a highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics. It is another object to manufacture a highly reliable semiconductor device at lower cost with high productivity. In a method for manufacturing a semiconductor device which includes a thin film transistor where a semiconductor layer having a channel formation region, a source region, and a drain region are formed using an oxide semiconductor layer, heat treatment (heat treatment for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor layer and reduce impurities such as moisture. Moreover, the oxide semiconductor layer subjected to the heat treatment is slowly cooled under an oxygen atmosphere. | 06-20-2013 |
20130178015 | METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - An object is to manufacture a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (for dehydration or dehydrogenation) is performed to improve the purity of the oxide semiconductor film and reduce impurities including moisture or the like. After that, slow cooling is performed under an oxygen atmosphere. Besides impurities including moisture or the like exiting in the oxide semiconductor film, heat treatment causes reduction of impurities including moisture or the like exiting in a gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor and in contact therewith. | 07-11-2013 |
20130228777 | SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF - In a bottom-gate thin film transistor using the stack of the first oxide semiconductor layer and the second oxide semiconductor layer, an oxide insulating layer serving as a channel protective layer is formed over and in contact with part of the oxide semiconductor layer overlapping with a gate electrode layer. In the same step as formation of the insulating layer, an oxide insulating layer covering a peripheral portion (including a side surface) of the stack of the oxide semiconductor layers is formed. | 09-05-2013 |
20130285052 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to provide a semiconductor device including a thin film transistor which includes an oxide semiconductor layer and has high electric characteristics. An oxide semiconductor layer including SiO | 10-31-2013 |
20130309822 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An insulating layer which releases a large amount of oxygen is used as an insulating layer in contact with a channel region of an oxide semiconductor layer, and an insulating layer which releases a small amount of oxygen is used as an insulating layer in contact with a source region and a drain region of the oxide semiconductor layer. By releasing oxygen from the insulating layer which releases a large amount of oxygen, oxygen deficiency in the channel region and an interface state density between the insulating layer and the channel region can be reduced, so that a highly reliable semiconductor device having small variation in electrical characteristics can be manufactured. The source region and the drain region are provided in contact with the insulating layer which releases a small amount of oxygen, thereby suppressing the increase of the resistance of the source region and the drain region. | 11-21-2013 |
20130328044 | MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE - An object is to provide a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, impurities such as moisture existing in the gate insulating layer are reduced before formation of the oxide semiconductor film, and then heat treatment (heat treatment for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor film and reduce impurities such as moisture. After that, slow cooling is performed in an oxygen atmosphere. Besides impurities such as moisture existing in the gate insulating layer and the oxide semiconductor film, impurities such as moisture existing at interfaces between the oxide semiconductor film and upper and lower films provided in contact therewith are reduced. | 12-12-2013 |
20140011319 | SEMICONDUCTOR DEVICE - An insulating layer containing a silicon peroxide radical is used as an insulating layer in contact with an oxide semiconductor layer for forming a channel. Oxygen is released from the insulating layer, whereby oxygen deficiency in the oxide semiconductor layer and an interface state between the insulating layer and the oxide semiconductor layer can be reduced. Accordingly, a semiconductor device where reliability is high and variation in electric characteristics is small can be manufactured. | 01-09-2014 |
20140011320 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to provide a high reliable semiconductor device including a thin film transistor having stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (which is for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor film and reduce impurities such as moisture. Besides impurities such as moisture existing in the oxide semiconductor film, heat treatment causes reduction of impurities such as moisture existing in the gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor film and are in contact with the oxide semiconductor film. | 01-09-2014 |
20140030846 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is, in a thin film transistor in which an oxide semiconductor is used as an active layer, to prevent change in composition, film quality, an interface, or the like of an oxide semiconductor region serving as an active layer, and to stabilize electrical characteristics of the thin film transistor. In a thin film transistor in which a first oxide semiconductor region is used as an active layer, a second oxide semiconductor region having lower electrical conductivity than the first oxide semiconductor region is formed between the first oxide semiconductor region and a protective insulating layer for the thin film transistor, whereby the second oxide semiconductor region serves as a protective layer for the first oxide semiconductor region; thus, change in composition or deterioration in film quality of the first oxide semiconductor region can be prevented, and electrical characteristics of the thin film transistor can be stabilized. | 01-30-2014 |
20140048798 | SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THE SAME - An object is to manufacture and provide a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which a semiconductor layer including a channel formation region serves as an oxide semiconductor film, heat treatment for reducing impurities such as moisture (heat treatment for dehydration or dehydrogenation) is performed after an oxide insulating film serving as a protective film is formed in contact with an oxide semiconductor layer. Then, the impurities such as moisture, which exist not only in a source electrode layer, in a drain electrode layer, in a gate insulating layer, and in the oxide semiconductor layer but also at interfaces between the oxide semiconductor film and upper and lower films which are in contact with the oxide semiconductor layer, are reduced. | 02-20-2014 |
20140073085 | METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - It is an object to provide a highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics. It is another object to manufacture a highly reliable semiconductor device at lower cost with high productivity. In a method for manufacturing a semiconductor device which includes a thin film transistor where a semiconductor layer including a channel formation region using an oxide semiconductor layer, a source region, and a drain region are formed using an oxide semiconductor layer, heat treatment for reducing impurities such as moisture (heat treatment for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor layer. | 03-13-2014 |
20140113406 | METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - An object is to manufacture a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (for dehydration or dehydrogenation) is performed to improve the purity of the oxide semiconductor film and reduce impurities including moisture or the like. After that, slow cooling is performed under an oxygen atmosphere. Besides impurities including moisture or the like exiting in the oxide semiconductor film, heat treatment causes reduction of impurities including moisture or the like exiting in a gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor and in contact therewith. | 04-24-2014 |
20140113687 | SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF - A semiconductor device including a thin film transistor which includes an oxide semiconductor layer and has high electric characteristics and reliability. Film deposition is performed using an oxide semiconductor target containing an insulator (an insulating oxide, an insulating nitride, silicon oxynitride, aluminum oxynitride, or the like), typically SiO | 04-24-2014 |
20140120660 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An insulating layer which releases a large amount of oxygen is used as an insulating layer in contact with a channel region of an oxide semiconductor layer, and an insulating layer which releases a small amount of oxygen is used as an insulating layer in contact with a source region and a drain region of the oxide semiconductor layer. By releasing oxygen from the insulating layer which releases a large amount of oxygen, oxygen deficiency in the channel region and an interface state density between the insulating layer and the channel region can be reduced, so that a highly reliable semiconductor device having small variation in electrical characteristics can be manufactured. The source region and the drain region are provided in contact with the insulating layer which releases a small amount of oxygen, thereby suppressing the increase of the resistance of the source region and the drain region. | 05-01-2014 |
20140197406 | TRANSISTOR AND DISPLAY DEVICE - It is an object to manufacture a highly reliable display device using a thin film transistor having favorable electric characteristics and high reliability as a switching element. In a bottom gate thin film transistor including an amorphous oxide semiconductor, an oxide conductive layer having a crystal region is formed between an oxide semiconductor layer which has been dehydrated or dehydrogenated by heat treatment and each of a source electrode layer and a drain electrode layer which are formed using a metal material. Accordingly, contact resistance between the oxide semiconductor layer and each of the source electrode layer and the drain electrode layer can be reduced; thus, a thin film transistor having favorable electric characteristics and a highly reliable display device using the thin film transistor can be provided. | 07-17-2014 |
20140209901 | DISPLAY DEVICE INCLUDING TRANSISTOR AND MANUFACTURING METHOD THEREOF - An object is to provide a display device which operates stably with use of a transistor having stable electric characteristics. In manufacture of a display device using transistors in which an oxide semiconductor layer is used for a channel formation region, a gate electrode is further provided over at least a transistor which is applied to a driver circuit. In manufacture of a transistor in which an oxide semiconductor layer is used for a channel formation region, the oxide semiconductor layer is subjected to heat treatment so as to be dehydrated or dehydrogenated; thus, impurities such as moisture existing in an interface between the oxide semiconductor layer and the gate insulating layer provided below and in contact with the oxide semiconductor layer and an interface between the oxide semiconductor layer and a protective insulating layer provided on and in contact with the oxide semiconductor layer can be reduced. | 07-31-2014 |
20140217402 | METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - It is an object to provide a highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics. It is another object to manufacture a highly reliable semiconductor device at lower cost with high productivity. In a method for manufacturing a semiconductor device which includes a thin film transistor where a semiconductor layer having a channel formation region, a source region, and a drain region are formed using an oxide semiconductor layer, heat treatment (heat treatment for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor layer and reduce impurities such as moisture. Moreover, the oxide semiconductor layer subjected to the heat treatment is slowly cooled under an oxygen atmosphere. | 08-07-2014 |
20140239297 | SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - It is an object to manufacture a semiconductor device in which a transistor including an oxide semiconductor has normally-off characteristics, small fluctuation in electric characteristics, and high reliability. First, first heat treatment is performed on a substrate, a base insulating layer is formed over the substrate, an oxide semiconductor layer is formed over the base insulating layer, and the step of performing the first heat treatment to the step of forming the oxide semiconductor layer are performed without exposure to the air. Next, after the oxide semiconductor layer is formed, second heat treatment is performed. An insulating layer from which oxygen is released by heating is used as the base insulating layer. | 08-28-2014 |
20140246673 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to improve field effect mobility of a thin film transistor using an oxide semiconductor. Another object is to suppress increase in off current even in a thin film transistor with improved field effect mobility. In a thin film transistor using an oxide semiconductor layer, by forming a semiconductor layer having higher electrical conductivity and a smaller thickness than the oxide semiconductor layer between the oxide semiconductor layer and a gate insulating layer, field effect mobility of the thin film transistor can be improved, and increase in off current can be suppressed. | 09-04-2014 |
20140252347 | SEMICONDUCTOR DEVICE - Disclosed is a semiconductor device with a transistor in which an oxide semiconductor is used. An insulating layer on a back channel side of the oxide semiconductor layer has capacitance of lower than or equal to 2×10 | 09-11-2014 |
20140252348 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to increase field effect mobility of a thin film transistor including an oxide semiconductor. Another object is to stabilize electrical characteristics of the thin film transistor. In a thin film transistor including an oxide semiconductor layer, a semiconductor layer or a conductive layer having higher electrical conductivity than the oxide semiconductor is formed over the oxide semiconductor layer, whereby field effect mobility of the thin film transistor can be increased. Further, by forming a semiconductor layer or a conductive layer having higher electrical conductivity than the oxide semiconductor between the oxide semiconductor layer and a protective insulating layer of the thin film transistor, change in composition or deterioration in film quality of the oxide semiconductor layer is prevented, so that electrical characteristics of the thin film transistor can be stabilized. | 09-11-2014 |
20140256086 | MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE - A transistor with superior electric characteristics is manufactured. An oxide insulating film is formed over a substrate, an oxide semiconductor film is formed over the oxide insulating film, heat treatment is then conducted at a temperature at which hydrogen contained in the oxide semiconductor film is desorbed and part of oxygen contained in the oxide insulating film is desorbed, then the heated oxide semiconductor film is etched into a predetermined shape to form an island-shaped oxide semiconductor film, a pair of electrodes is formed over the island-shaped oxide semiconductor film, a gate insulating film is formed over the pair of electrodes and the island-shaped oxide semiconductor film, and a gate electrode is formed over the gate insulating film. | 09-11-2014 |
20140319520 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to provide a semiconductor device including a thin film transistor which includes an oxide semiconductor layer and has high electric characteristics. An oxide semiconductor layer including SiO | 10-30-2014 |
20140342498 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - A semiconductor device is manufactured using a transistor in which an oxide semiconductor is included in a channel region and variation in electric characteristics due to a short-channel effect is less likely to be caused. The semiconductor device includes an oxide semiconductor film having a pair of oxynitride semiconductor regions including nitrogen and an oxide semiconductor region sandwiched between the pair of oxynitride semiconductor regions, a gate insulating film, and a gate electrode provided over the oxide semiconductor region with the gate insulating film positioned therebetween. Here, the pair of oxynitride semiconductor regions serves as a source region and a drain region of the transistor, and the oxide semiconductor region serves as the channel region of the transistor. | 11-20-2014 |
20140367680 | METHOD FOR MANUFACTURING OXIDE SEMICONDUCTOR DEVICE - An object is to provide a semiconductor device having a structure with which parasitic capacitance between wirings can be sufficiently reduced. An oxide insulating layer serving as a channel protective layer is formed over part of an oxide semiconductor layer overlapping with a gate electrode layer. In the same step as formation of the oxide insulating layer, an oxide insulating layer covering a peripheral portion of the oxide semiconductor layer is formed. The oxide insulating layer which covers the peripheral portion of the oxide semiconductor layer is provided to increase the distance between the gate electrode layer and a wiring layer formed above or in the periphery of the gate electrode layer, whereby parasitic capacitance is reduced. | 12-18-2014 |
20140377907 | SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME - An object is to provide a high reliable semiconductor device including a thin film transistor having stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (which is for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor film and reduce impurities such as moisture. Besides impurities such as moisture existing in the oxide semiconductor film, heat treatment causes reduction of impurities such as moisture existing in the gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor film and are in contact with the oxide semiconductor film. | 12-25-2014 |
20150031169 | METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - An object is to manufacture a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (for dehydration or dehydrogenation) is performed to improve the purity of the oxide semiconductor film and reduce impurities including moisture or the like. After that, slow cooling is performed under an oxygen atmosphere. Besides impurities including moisture or the like exiting in the oxide semiconductor film, heat treatment causes reduction of impurities including moisture or the like exiting in a gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor and in contact therewith. | 01-29-2015 |
20150048364 | OXIDE SEMICONDUCTOR, THIN FILM TRANSISTOR, AND DISPLAY DEVICE - An object is to control composition and a defect of an oxide semiconductor, another object is to increase a field effect mobility of a thin film transistor and to obtain a sufficient on-off ratio with a reduced off current. A solution is to employ an oxide semiconductor whose composition is represented by InMO | 02-19-2015 |
20150053975 | SEMICONDUCTOR DEVICE - In a transistor having a top-gate structure in which a gate electrode layer overlaps with an oxide semiconductor layer which faints a channel region with a gate insulating layer interposed therebetween, when a large amount of hydrogen is contained in the insulating layer, hydrogen is diffused into the oxide semiconductor layer because the insulating layer is in contact with the oxide semiconductor layer; thus, electric characteristics of the transistor are degraded. An object is to provide a semiconductor device having favorable electric characteristics. An insulating layer in which the concentration of hydrogen is less than 6×10 | 02-26-2015 |
20150072470 | METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE - A highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics, and a manufacturing method thereof. In the manufacturing method of the semiconductor device which includes a thin film transistor where a semiconductor layer including a channel formation region is an oxide semiconductor layer, heat treatment which reduces impurities such as moisture to improve the purity of the oxide semiconductor layer and oxidize the oxide semiconductor layer (heat treatment for dehydration or dehydrogenation) is performed. Not only impurities such as moisture in the oxide semiconductor layer but also those existing in a gate insulating layer are reduced, and impurities such as moisture existing in interfaces between the oxide semiconductor layer and films provided over and under and in contact with the oxide semiconductor layer are reduced. | 03-12-2015 |