Vertical semiconductor device and manufacturing method thereof
View Patent ↗A semiconductor device includes an n-type semiconductor substrate ( 1 ) including a p-type collector layer ( 2 ) formed in a second main surface side thereof, a trench ( 13 ) is formed in a peripheral portion of the semiconductor substrate ( 1 ) so as to surround the inside and reach the collector layer ( 2 ) from a first main surface of the semiconductor substrate ( 1 ), and a p-type isolation region ( 14 ) formed by diffusion from a sidewall of the trench ( 13 ) is provided to be connected to the collector layer ( 2 ). The trench ( 13 ) is filled with a filling material ( 16 ).
1. A vertical semiconductor device comprising:
a semiconductor substrate of a first conductivity type including a first main surface and a second main surface opposed to said first main surface, said semiconductor substrate including an element region and a peripheral provided so as to surround said element region;
a first impurity region of a second conductivity type having a higher impurity concentration than said first conductivity type of said semiconductor substrate, formed inside said semiconductor substrate so as to be exposed at said second main surface;
a trench provided in said peripheral region and having an almost vertical sidewall with reference to said first main surface; and
a second impurity region of said second conductivity type formed along said sidewall of said trench inside of said semiconductor substrate in a prescribed thickness and electrically connected to said first impurity region, wherein
a ratio d/w (aspect ratio) between a depth d and an opening width w of said trench is 5 or more and 100 or less.
2. The vertical semiconductor device according to claim 1 , further comprising a filling material filled in said trench.
3. The vertical semiconductor device according to claim 1 , wherein
said trench is formed continuously so as to surround said element region and includes a first sidewall close to said element region and a second sidewall far from said element region, and
said second impurity region includes second impurity regions on said first sidewall side and said second sidewall side which are formed in a prescribed thickness from said first and second sidewalls to the inside of said semiconductor substrate, respectively,
said vertical semiconductor device further comprising:
a field plate in electrical contact with said second impurity region on said second sidewall side.
4. A vertical semiconductor device comprising:
a semiconductor substrate of a first conductivity type including a first main surface and a second main surface opposed to said first main surface, said semiconductor substrate including an element region and a peripheral region provided so as to surround said element region;
a first impurity region of a second conductivity type having a higher impurity concentration than said first conductivity type of said semiconductor substrate, formed inside said semiconductor substrate so as to be exposed at said second main surface;
a trench provided in said peripheral region to reach said first impurity region from said first main surface and having an almost vertical sidewall with reference to said first main surface; and
a filling material filled in said trench and being made of a semiconductor material of said second conductivity type.
5. A vertical semiconductor device comprising:
a semiconductor substrate of a first conductivity type including a first main surface and a second main surface opposed to said first main surface, said semiconductor substrate including an element region and a peripheral region provided so as to surround said element region;
a first impurity region of a second conductivity type having a higher impurity concentration than said first conductivity type of said semiconductor substrate, formed inside said semiconductor substrate so as to be exposed at said second main surface;
a plurality of trenches provided in said peripheral region so as to surround said element region with a prescribed distance therebetween; and
a plurality of second impurity regions of said second conductivity type formed along sidewalls of said plurality of said trenches inside of said semiconductor substrate in a prescribed thickness and electrically connected to said first impurity region, respectively.
6. The vertical semiconductor device according to claim 5 , wherein
a distance between said plurality of said second impurity regions is 15 μm or less.