High voltage power MOS device
AssigneeIXYS Corporation
InventorsUlrich Kelberlau, Nathan Zommer
Life of this patent
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Abstract
A switching device is described having a semiconductor substrate with a front side and a back side. The switching device includes a first transistor which includes a first region adjacent the front side, a second region within the first region, the semiconductor substrate, and at least one island region adjacent the backside. The switching device also includes a second transistor which includes the first region, the second region, the semiconductor substrate, and a third region coupled to the at least one island region.
Claims21
A method for fabricating a switching device comprising the steps of:
- providing a semiconductor substrate of a first conductivity type having a front side and a back side;
- forming a first region of a second conductivity type in the semiconductor substrate adjacent the front side;
- forming a second region of the first conductivity type within the first region and adjacent the front side;
- forming a plurality of island regions of the first conductivity type adjacent the back side;
- and
- forming a third region of the second conductivity type adjacent the back side, the third region being coupled to the island regions;
- wherein the first region, the second region, the semiconductor substrate, and the island regions form a first transistor, and wherein the first region, the second region, the semiconductor substrate, and the third region form a second transistor in parallel with the first transistor.
A method for forming a back side structure of a switching device comprising the steps of:
- introducing first impurities of a first conductivity type into a back side of a semiconductor crystal of a second conductivity type, thereby forming a first region of the first conductivity type adjacent the back side;
- forming a mask on the back side, the mask having a plurality of apertures;
- introducing second impurities of the second conductivity type into the back side via the apertures, thereby forming a plurality of island regions of the second conductivity type adjacent the back side;
- and
- introducing third impurities of the first conductivity type into the back side to form a second region of the first conductivity type further within the semiconductor crystal than the island regions.
Dependencies are inferred from the claim text.