Patent ID: 9231089
Filing Date: 2016-01-05
CPC Classification: H01L

Claim Text:
1. A bipolar semiconductor device comprising: a first terminal region in a semiconductor substrate, said semiconductor substrate having a top surface; a second terminal region in a first semiconductor layer on said top surface of said semiconductor substrate, said second terminal region being aligned above said first terminal region; a third terminal region in a second semiconductor layer on said first semiconductor layer, said third terminal region being aligned above said second terminal region; an opening extending vertically through said first semiconductor layer and positioned laterally adjacent to said second terminal region; an asymmetric trench in said semiconductor substrate aligned below said opening, said asymmetric trench having a first side adjacent to said first terminal region and a second side opposite said first side, said first side having a first angle relative to said top surface and said second side having a second angle relative to said top surface, said second angle being larger than said first angle; and, at least one isolation material filling said trench so as to form an asymmetric trench isolation region, said at least one isolation material also filling said opening.