Patent application number | Description | Published |
20090212354 | TRENCH MOSEFT WITH TRENCH GATES UNDERNEATH CONTACT AREAS OF ESD DIODE FOR PREVENTION OF GATE AND SOURCE SHORTATE - A trench DMOS transistor having overvoltage protection and prevention for shortage between gate and source when contact trenches are applied includes a substrate of a first conductivity type and a body region of a second conductivity type formed over the substrate. Trench gates extend through the body region and the substrate. An insulating oxide layer lines the trench and overlies the body region. A conductive electrode is deposited in the trench so that it overlies the insulating layer. A source region of the first conductivity type is formed in the body region adjacent to the trench. An undoped polysilicon layer overlies a portion of the insulating layer defining the Zener diode region. A plurality of cathode regions of the first conductivity type is formed in undoped polysilicon layer. At least one anode region is in contact with adjacent ones of the plurality of cathode regions. Trench gates underneath the Zener diode act as the buffer layer for prevention of shortage between gate and source. | 08-27-2009 |
20090212359 | TRENCHED MOSFET WITH TRENCHED SOURCE CONTACT - A trenched MOSFET with trenched source contact, comprising: a semiconductor region, further comprising a silicon substrate, a epitaxial layer corresponding to the drain region of the trenched MOSFET, a base layer corresponding to the body region of the trenched MOSFET, and a source layer corresponding to the source region of the trenched MOSFET; an interlayer oxide film formed on the source layer; a front metal layer formed on a upper surface of the semiconductor region; a back metal layer formed on a lower surface of the semiconductor region; a plurality of trenched gates formed to reach the epitaxial layer through the source layer and the base layer, and is covered by the interlayer oxide film; and a plurality of source contact trenches formed to reach the base layer through the interlayer oxide film and the source layer, and is covered by the front metal layer; wherein the silicon substrate, the epitaxial layer, the base layer, and the source layer are stacked in sequence; and each of the source contact trenches has a lateral contact layer at a sidewall thereof. | 08-27-2009 |
20090309097 | TESTING DEVICE ON WATER FOR MONITORING VERTICAL MOSFET ON-RESISTANCE - The present invention is to provide a testing device on wafer for monitoring vertical MOSFET on-resistance, formed on a substrate and the substrate comprising a first testing region; and a second testing region; wherein the first testing region and the second testing region are vertical MOSFETs respectively, which comprise at least a common gate region, at least a common drain region, and a plurality of source regions which are separated for each corresponding testing region. | 12-17-2009 |
20090309130 | METHOD OF FABRICATING COLLECTOR OF IGBT - The IGBT is described here that exhibits high breakdown voltage, low on-voltage together with high turn-off speed. The collector of IGBT is formed on the backside of the wafer which has n type float zone. Methods for the p-type collector is implemented by depositing a layer of BSG which is 0.05˜0.1 um on the backside of the wafer and removing it after short time deposition. A thin and high surface concentration p+ layer acts as P type collector of the IGBT is formed on the bottom surface of the wafer. The back metal electrode is sintered to form ohmic contact on the P type collector with high surface concentration. The hole injection efficiency is decreased with a thin layer p+ layer which hat means no P implantation is needed to form the collector and the speed performance of the IGBT is therefore improved. | 12-17-2009 |
20090309181 | TRENCH SCHOTTKY WITH MULTIPLE EPI STRUCTURE - A trench Schottky barrier rectifier includes an cathode electrode at a face of a semiconductor substrate and an multiple epitaxial structure in drift region which in combination provide high blocking voltage capability with low reverse-biased leakage current and low forward voltage. The multiple structure of the drift region contains a concentration of first conductivity dopants therein which comprises two or three different uniform value from a Schottky rectifying junction formed between the anode electrode and the drift region. The thickness of the insulating region (e.g., SiO2) in the MOS-filled trenches is greater than 1000 Å to simultaneously inhibit field crowing and increase the breakdown voltage of the device. The multiple epi structure is preferably formed by epitaxial growth from the cathode region and doped in-situ. | 12-17-2009 |
20090315103 | TRENCH MOSFET WITH SHALLOW TRENCH FOR GATE CHARGE REDUCTION - A power MOS device includes shallow trench structure for reduction of gate charge. To counteract the increase of Rds may caused by decreasing the depth of trench, the power MOS device further includes an arsenic Ion Implantation area underneath each trench bottom when N+ red phosphorus substrate is applied, and the concentration of said arsenic doped area is higher than that of epitaxial layer. As the shallow trench is performed, the gate contact trench could be easily etched over to penetrate the gate oxide, which will lead to a shortage of tungsten plug filled in gate contact trench to epitaixial layer. To prevent from this problem, a terrace poly gate is designed in a preferred embodiment of present invention. By using this method, the gate contact trench is lifted to avoid the shortage problem. | 12-24-2009 |
20100072543 | TRENCH MOSFET WITH ETCHING BUFFER LAYER IN TRENCH GATE - The present invention is to provide a trench MOSFET with an etching buffer layer in a trench gate, comprising: a substrate which has a first surface and a second surface opposite to each other and comprises at least a drain region, a gate region, and a source region which are constructed as a plurality of semiconductor cells with MOSFET effect; a plurality of gate trenches, each of which is extended downward from the first surface and comprises a gate oxide layer covered on a inner surface thereof and a gate conductive layer filled inside, comprised in the gate region; at least a drain metal layer formed on the second surface according to the drain region; at least a gate runner metal layer formed on the first surface according to the gate region; and at least a source metal layer formed on the first surface according to the source region; wherein the gate trenches distinguished into at least a second gate trench formed at a terminal of the source region and at least a first gate trenches wrapped in the source region; and the second gate trench comprises a gate contact hole which is filled with metal to form a gate metal contact plug, and a gate buffer layer which is formed in the gate conductive layer at the bottom of the gate contact hole in the second gate trench to prevent from over etching, causing gate-drain shortage. | 03-25-2010 |
20100090270 | TRENCH MOSFET WITH SHORT CHANNEL FORMED BY PN DOUBLE EPITAXIAL LAYERS - A power MOS device includes double epitaxial (P/N) structure is disclosed for reduction of channel length and better avalanche capability. In some embodiments, the power MOS device further includes an arsenic Ion implantation area underneath each rounded trench bottom to further enhance breakdown voltage and further reduce Rds, and the concentration of said arsenic doped area is higher than that of N-type epitaxial layer. As the gate contact trench could be easily etched over to penetrate the gate oxide, which will lead to a shortage of tungsten plug filled in gate contact trench to epitaixial layer, a terrace poly gate is designed in a preferred embodiment of present invention. By using this method, the gate contact trench is lifted to avoid the shortage problem. | 04-15-2010 |
20100171173 | TRENCH MOSFET WITH IMPROVED SOURCE-BODY CONTACT - A trench MOSFET with improved source-body contact structure is disclosed. The improved contact structure can enlarge the P+ area below to wrap the sidewalls and bottom of source-body contact within P-body region to further enhance the avalanche capability. On the other hand, one of the embodiments disclosed a wider tungsten plug structure to connect source metal, which helps to further reduce the source contact resistance. | 07-08-2010 |
20100224931 | TRENCH MOSEFT WITH TRENCH GATES UNDERNEATH CONTACT AREAS OF ESD DIODE FOR PREVENTION OF GATE AND SOURCE SHORTAGE - A trench DMOS transistor employing trench contacts has overvoltage protection for prevention of shortage between gate and source, comprising a plurality of first-type function trenched gates, at least one second-type function trenched gate and at least two third-type function trenched gates extending through body regions and into an epitaxial layer. The first-type function trenched gates are located in active area surrounded by a source region encompassed in the body region in the epitaxial layer for current conduction. The second-type function trenched gates are disposed underneath a gate metal with a gate trenched contacts filled with metal plug for gate metal connection. The third type function trenched gates are disposed directly and symmetrically underneath ESD trenched contact areas of anode and cathode in an ESD protection diode, serving as a buffer layer for prevention of gate-body shortage. | 09-09-2010 |