Trench-type insulated gate bipolar transistor
First Claim
1. A trench-type insulated gate bipolar transistor comprising:
- a drift layer of a first conductivity type;
well regions of a second conductivity type in the surface portion of the drift layer;
emitter regions of the first conductivity type in the respective well regions;
trenches extending from the emitter regions to the drift layer;
gate electrodes, each thereof being buried in each of the trenches with a gate insulation film interposed therebetween;
an emitter electrode in common contact with the emitter regions and the well regions;
a collector layer of the second conductivity type on the back surface of the drift layer;
a collector electrode located on the collector layer;
wherein the well regions are formed selectively; and
wherein the drift layer includes extended portions that extend between the well regions.
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Accused Products
Abstract
A trench-type IGBT is disclosed that facilitates reducing the tradeoff relation between the saturation voltage and the turn-off loss. The trench-type IGBT'"'"'s includes the following characteristic structures: (1) the drift layer of the first conductivity type has extended portions extended between the selectively formed well regions of the second conductivity type; (2) the well regions of the second conductivity type are formed selectively in the respective surface portions of the drift layer of the first conductivity type, and the doped regions of the first conductivity type, doped more heavily than the drift layer, are formed in the other surface portions of the drift layer, wherein the well regions are not formed; (3) the auxiliary gate electrode is disposed above the extended portion of the drift layer of the first conductivity type extended between p-type well regions or above the doped region of the first conductivity type with the auxiliary gate insulation film interposed therebetween; (4) the trenches include respective portions not surrounded by any well region of the second conductivity type nor by any emitter region of the first conductivity type; and (5) the ratio Wt/Wp of the width Wt of the trench and the width Wp of the p-type well region is set at a value between 1 and 20.
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Citations
21 Claims
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1. A trench-type insulated gate bipolar transistor comprising:
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a drift layer of a first conductivity type;
well regions of a second conductivity type in the surface portion of the drift layer;
emitter regions of the first conductivity type in the respective well regions;
trenches extending from the emitter regions to the drift layer;
gate electrodes, each thereof being buried in each of the trenches with a gate insulation film interposed therebetween;
an emitter electrode in common contact with the emitter regions and the well regions;
a collector layer of the second conductivity type on the back surface of the drift layer;
a collector electrode located on the collector layer;
wherein the well regions are formed selectively; and
wherein the drift layer includes extended portions that extend between the well regions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A trench-type insulated gate bipolar transistor comprising:
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a drift layer of a first conductivity type;
well regions of a second conductivity type in the surface portion of the drift layer;
emitter regions of the first conductivity type in the respective well regions;
trenches extending from the emitter regions to the drift layer;
gate electrodes, each thereof being buried in each of the trenches with a gate insulation film interposed therebetween;
an emitter electrode in common contact with the emitter regions and the well regions;
a collector layer of the second conductivity type on the back surface of the drift layer;
a collector electrode on the collector layer;
wherein the well regions are formed selectively; and
wherein the doped regions of the first conductivity type in the respective surface portions of the drift layer, where the well regions are not formed, the doped regions being doped more heavily than the drift layer. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A trench-type insulated gate bipolar transistor comprising:
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a drift layer of a first conductivity type;
well regions of a second conductivity type in the surface portion of the drift layer;
emitter regions of the first conductivity type in the respective well regions;
trenches extending from the emitter regions to the drift layer;
gate electrodes, each thereof being buried in each of the trenches with a gate insulation film interposed therebetween;
an emitter electrode in common contact with the emitter regions and the well regions;
a collector layer of the second conductivity type on the back surface of the drift layer;
a collector electrode on the collector layer; and
wherein the ratio Wt/Wp of the bottom width Wt of the trench and the width Wp of the well region between the trenches being set at a value between 1 and 20.
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Specification