Insulated gate bipolar transistor
AssigneeFuji Electric Co., Ltd.
InventorHong-fei LU
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Abstract
IGBT includes an n-type drift layer, an n-type accumulation layer provided on the upper surface of the drift layer having higher impurity concentration than the drift layer, a base layer provided on the upper surface of the accumulation layer, a gate electrode embedded inside a striped gate trench penetrating the base layer and the storage layer through a gate insulating film, and a dummy electrode embedded inside a dummy trench provided to face the gate trench across the base layer and the accumulation layer through a dummy insulating film. The base layer has a p-type active base region and a p-type floating base region arranged alternately in the extending direction of the gate trench, and an n-type base isolation region isolating the active base region and the floating base region.
Claims11
An insulated gate bipolar transistor comprising:
- a drift layer of a first conductivity type;
- an accumulation layer of the first conductivity type arranged on an upper surface of the drift layer, having an impurity concentration higher than an impurity concentration of the drift layer;
- a base layer arranged on an upper surface of the accumulation layer;
- a gate electrode embedded through a gate insulating film inside a stripe-shaped gate trench penetrating the base layer and the accumulation layer;
- a dummy electrode embedded through a dummy insulating film inside a stripe-shaped dummy trench penetrating the base layer and the accumulation layer;
- and
- an emitter region of the first conductivity type arranged in an upper portion of the base layer, having a higher impurity concentration than the drift region, wherein
- the base layer includes an active base region of a second conductivity type in which the emitter region is arranged in the upper portion, connected to emitter potential, a floating base region of the second conductivity type set at floating potential, and a base isolation region of the first conductivity type isolating the active base region and the floating base region, and
- in a mesa provided between the gate trench and the dummy trench, the active base region and the floating base region are alternately arranged via the base isolation region in an extending direction of the gate trench.
The insulated gate bipolar transistor according to claim wherein the impurity concentration of the base isolation region is more than or equal to 1×1016 cm−3 and less than or equal to 1×1017 cm−3.
Dependencies are inferred from the claim text.