Patent application number | Description | Published |
20090057685 | BIPOLAR DEVICE AND FABRICATION METHOD THEREOF - In a mesa type bipolar transistor or a thyristor, since carriers injected from an emitter layer or an anode layer to a base layer or a gate layer diffuse laterally and are recombined, reduction in the size and improvement for the switching frequency is difficult. | 03-05-2009 |
20090064785 | Integrated micro electro-mechanical system and manufacturing method thereof - In the manufacturing technology of an integrated MEMS in which a semiconductor integrated circuit (CMOS or the like) and a micro machine are monolithically integrated on a semiconductor substrate, a technology capable of manufacturing the integrated MEMS without using a special process different from the normal manufacturing technology of a semiconductor integrated circuit is provided. A MEMS structure is formed together with an integrated circuit by using the CMOS integrated circuit process. For example, when forming an acceleration sensor, a structure composed of a movable mass, an elastic beam and a fixed beam is formed by using the CMOS interconnect technology. Thereafter, an interlayer dielectric and the like are etched by using the CMOS process to form a cavity. Then, fine holes used in the etching are sealed with a dielectric. | 03-12-2009 |
20090085044 | SILICON CARBIDE SEMICONDUCTOR SUBSTRATE AND SILICON CARBIDE SEMICONDUCTOR DEVICE BY USING THEREOF - A manufacturing method is provided for a silicon carbide semiconductor substrate adapted for reduced basal plane dislocations in a silicon carbide epitaxial layer. Between a silicon carbide epitaxial layer for device fabrication (i.e., a drift layer) and a base substrate formed of a silicon carbide single-crystal wafer, a highly efficient dislocation conversion layer through which any basal plane dislocations in the silicon carbide single-crystal wafer are converted into threading edge dislocations very efficiently when the dislocations propagate into the layer epitaxially grown is provided by epitaxial growth. Assigning to the dislocation conversion layer a donor concentration lower than that of the drift layer, therefore, allows the above conversion of a larger number of basal plane dislocations than the case where the drift layer exists alone (without the dislocation conversion layer). | 04-02-2009 |
20090209090 | MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE - A problem in the conventional technique is that metal contamination on a silicon carbide surface is not sufficiently removed in a manufacturing method of a semiconductor device using a monocrystalline silicon carbide substrate. Accordingly, there is a high possibility that the initial characteristics of a manufactured silicon carbide semiconductor device are deteriorated and the yield rate is decreased. Further, it is conceivable that the metal contamination has an adverse affect even on the long-term reliability of a semiconductor device. In a manufacturing method of a semiconductor device using a monocrystalline silicon carbide substrate, there is applied a metal contamination removal process, on a silicon carbide surface, including a step of oxidizing the silicon carbide surface and a step of removing a film primarily including silicon dioxide formed on the silicon carbide surface by the step. | 08-20-2009 |
20090302328 | Silicon carbide semiconductor substrate and method of manufacturing the same - A buffer layer configured of the same conductive semiconductor layers of two or more layers as a drift layer is installed by epitaxial growth between a first semiconductor layer configuring the drift layer that is a layer in which components of the semiconductor device are made and a base substrate including a silicon carbide single crystal wafer. A step of donor concentration is provided at an interface between the drift layer and the buffer layer, an interface between the semiconductor layers configuring the buffer layer, and an interface between the buffer layer and the base substrate and the donor concentration of the drift layer side is lower than that of the base substrate side, thereby making it possible to convert most basal plane dislocations into threading edge dislocations as compared to the drift layer having one layer or the buffer layer configured of one layer. | 12-10-2009 |
20100025739 | SEMICONDUCTOR DEVICE WITH LARGE BLOCKING VOLTAGE AND METHOD OF MANUFACTURING THE SAME - A normally-off type junction FET in which a channel resistance is reduced without lowering its blocking voltage is provided. In a junction FET formed with using a substrate made of silicon carbide, an impurity concentration of a channel region (second epitaxial layer) is made higher than an impurity concentration of a first epitaxial layer to be a drift layer. The channel region is formed of a first region in which a channel width is constant and a second region below the first region in which the channel width becomes wider toward the drain (substrate) side. A boundary between the first epitaxial layer and the second epitaxial layer is positioned in the second region in which the channel width becomes wider toward the drain (substrate) side. | 02-04-2010 |
20100163935 | SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME - In a junction FET of a normally-off type, a technique capable of achieving both of improvement of a blocking voltage and reduction of an ON resistance is provided. In a junction FET using silicon carbide as a substrate material, impurities are doped to a vicinity of a p-n junction between a gate region and a channel-formed region, the impurities having a conductive type which is reverse to that of impurities doped in the gate region and same as that of impurities doped in the channel-formed region. In this manner, an impurity profile of the p-n junction becomes abrupt, and further, an impurity concentration of a junction region forming the p-n junction with the gate region in the channel-formed region is higher than those of a center region in the channel-formed region and of an epitaxial layer. | 07-01-2010 |
20110018004 | SEMICONDUCTOR DEVICE WITH LARGE BLOCKING VOLTAGE AND MANUFACTURING METHOD THEREOF - There is no effective method for fabricating a semiconductor power device containing UMOSFET possessing large channel mobility and whose threshold voltage can be lowered with no loss in blocking voltage. A semiconductor device with large blocking voltage is provided utilizing silicon carbide trench MOSFET possessing both narrow regions where the p body concentration is low, and wide regions where the p body concentration is high. | 01-27-2011 |
20110198613 | SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD OF THE SAME - The leakage current generated in a pn junction region between a gate and a source is reduced in a junction FET using a silicon carbide substrate. In a trench junction FET using a silicon carbide substrate, nitrogen is introduced into a sidewall and a bottom surface of a trench, thereby forming an n type layer and an n | 08-18-2011 |
20110220916 | ELECTRONIC CIRCUIT DEVICE - A normally-off type silicon carbide junction FET has a problem that the gate thereof is not easy to use due to inferiority in the characteristics of it. This problem occurs because in order to achieve normally-off, the gate voltage should be off at 0V and at the same time, the ON-state gate voltage should be suppressed to about 2.5V to prevent the passage of an electric current through a pn junction between gate and source. Accordingly, a range from the threshold voltage to the ON-state gate voltage is only from about 1 V to 2V and it is difficult to control the gate voltage. Provided in the present invention is an electronic circuit device obtained by coupling, to a gate of a normally-off type silicon carbide junction FET, an element having a capacitance equal to or a little smaller than the gate capacitance of the junction FET. | 09-15-2011 |
20120193641 | NORMALLY-OFF POWER JFET AND MANUFACTURING METHOD THEREOF - In general, in a semiconductor active element such as a normally-off JFET based on SiC in which an impurity diffusion speed is significantly lower than in silicon, gate regions are formed through ion implantation into the side walls of trenches formed in source regions. However, to ensure the performance of the JFET, it is necessary to control the area between the gate regions thereof with high precision. Besides, there is such a problem that, since a heavily doped PN junction is formed by forming the gate regions in the source regions, an increase in junction current cannot be avoided. The present invention provides a normally-off power JFET and a manufacturing method thereof and forms the gate regions according to a multi-epitaxial method which repeats a process including epitaxial growth, ion implantation, and activation annealing a plurality of times. | 08-02-2012 |
20130056754 | ELECTRONIC CIRCUIT DEVICE - A normally-off type silicon carbide junction FET has a problem that the gate thereof is not easy to use due to inferiority in the characteristics of it. This problem occurs because in order to achieve normally-off, the gate voltage should be off at 0V and at the same time, the ON-state gate voltage should be suppressed to about 2.5V to prevent the passage of an electric current through a pn junction between gate and source. Accordingly, a range from the threshold voltage to the ON-state gate voltage is only from about 1 V to 2V and it is difficult to control the gate voltage. Provided in the present invention is an electronic circuit device obtained by coupling, to a gate of a normally-off type silicon carbide junction FET, an element having a capacitance equal to or a little smaller than the gate capacitance of the junction FET. | 03-07-2013 |
20130105819 | SEMICONDUCTOR DEVICE | 05-02-2013 |
20130105820 | TRENCH TYPE SCHOTTKY JUNCTION SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF | 05-02-2013 |
20130140584 | SEMICONDUCTOR DEVICE - Disclosed is a JBS diode wherein an increase in an on-voltage is suppressed by sufficiently spreading a current to the lower portion of a junction barrier (p | 06-06-2013 |
20130244407 | MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE - A problem in the conventional technique is that metal contamination on a silicon carbide surface is not sufficiently removed in a manufacturing method of a semiconductor device using a monocrystalline silicon carbide substrate. Accordingly, there is a high possibility that the initial characteristics of a manufactured silicon carbide semiconductor device are deteriorated and the yield rate is decreased. Further, it is conceivable that the metal contamination has an adverse affect even on the long-term reliability of a semiconductor device. In a manufacturing method of a semiconductor device using a monocrystalline silicon carbide substrate, there is applied a metal contamination removal process, on a silicon carbide surface, including a step of oxidizing the silicon carbide surface and a step of removing a film primarily including silicon dioxide formed on the silicon carbide surface by the step. | 09-19-2013 |
20130334542 | NORMALLY-OFF POWER JFET AND MANUFACTURING METHOD THEREOF - In general, in a semiconductor active element such as a normally-off JFET based on SiC in which an impurity diffusion speed is significantly lower than in silicon, gate regions are formed through ion implantation into the side walls of trenches formed in source regions. However, to ensure the performance of the JFET, it is necessary to control the area between the gate regions thereof with high precision. Besides, there is such a problem that, since a heavily doped PN junction is formed by forming the gate regions in the source regions, an increase in junction current cannot be avoided. The present invention provides a normally-off power JFET and a manufacturing method thereof and forms the gate regions according to a multi-epitaxial method which repeats a process including epitaxial growth, ion implantation, and activation annealing a plurality of times. | 12-19-2013 |
20150041829 | ELECTRONIC CIRCUIT DEVICE - A normally-off type silicon carbide junction FET has a problem that the gate thereof is not easy to use due to inferiority in the characteristics of it. This problem occurs because in order to achieve normally-off, the gate voltage should be off at 0V and at the same time, the ON-state gate voltage should be suppressed to about 2.5V to prevent the passage of an electric current through a pn junction between gate and source. Accordingly, a range from the threshold voltage to the ON-state gate voltage is only from about 1 V to 2V and it is difficult to control the gate voltage. Provided in the present invention is an electronic circuit device obtained by coupling, to a gate of a normally-off type silicon carbide junction FET, an element having a capacitance equal to or a little smaller than the gate capacitance of the junction FET. | 02-12-2015 |
20150060887 | NORMALLY-OFF POWER JFET AND MANUFACTURING METHOD THEREOF - In general, in a semiconductor active element such as a normally-off JFET based on SiC in which an impurity diffusion speed is significantly lower than in silicon, gate regions are formed through ion implantation into the side walls of trenches formed in source regions. However, to ensure the performance of the JFET, it is necessary to control the area between the gate regions thereof with high precision. Besides, there is such a problem that, since a heavily doped PN junction is formed by forming the gate regions in the source regions, an increase in junction current cannot be avoided. The present invention provides a normally-off power JFET and a manufacturing method thereof and forms the gate regions according to a multi-epitaxial method which repeats a process including epitaxial growth, ion implantation, and activation annealing a plurality of times. | 03-05-2015 |