Integrated fet and schottky device
View Patent ↗A semiconductor device including a schottky device and a trench type semiconductor switching device such as a MOSFET formed in a common die.
1. A method for manufacturing a semiconductor device, comprising:
providing a semiconductor die of one conductivity type;
forming a termination trench in said semiconductor die;
forming a mask over a portion of said semiconductor die;
forming laterally spaced base regions of another conductivity type in said semiconductor die by implanting dopants of said another conductivity type into regions of said semiconductor die not covered by said mask, said base regions being spaced from one another by a region of said one conductivity disposed below said mask;
forming spaced trenches after forming said base regions through said base regions to serve as gate trenches for a semiconductor switching device;
forming a schottky device over said region of said one conductivity type between said base regions;
forming source regions in said base regions adjacent said trenches; and
forming a common first contact in contact with said schottky device and said source regions wherein said termination trench extends to a depth below said gate trenches, and is formed in a step independent of a step for forming said gate trenches.
2. A method according to claim 1 , wherein said semiconductor switching device is a trench MOSFET.
3. A method according to claim 1 , wherein said schottky device includes a schottky barrier comprised of TiSi 2 .
4. A method according to claim 1 , further comprising a trench on each side of said region of said one conductivity between said base regions, each trench having an oxide formed on its sidewalls and containing a conductive material, wherein said schottky device includes a schottky barrier in schottky contact with said region of said one conductivity and said conductive material.
5. A method according to claim 3 , wherein said schottky device includes a schottky barrier.
6. A method for manufacturing a semiconductor device, comprising:
providing a semiconductor die of one conductivity type;
forming a mask over a portion of said semiconductor die;
forming laterally spaced base regions of another conductivity type in said semiconductor die by implanting dopants of said another conductivity type into regions of said semiconductor die not covered by said mask, said base regions being spaced from one another by a region of said one conductivity disposed below said mask;
forming spaced trenches after forming said base regions through said base regions to serve as gate trenches for a semiconductor switching device;
forming a schottky device over said region of said one conductivity type between said base regions;
forming source regions in said base regions adjacent said trenches; and
forming a common first contact in contact with said schottky device and said source regions.
7. A method according to claim 6 , wherein said semiconductor switching device is a trench MOSFET.
8. A method according to claim 6 , wherein said schottky device includes a schottky barrier comprised of TiSi 2 .
9. A method according to claim 6 , further comprising a trench on each side of said region of said one conductivity between said base regions, each trench having an oxide formed on its sidewalls and containing a conductive material, wherein said schottky device includes a schottky barrier in schottky contact with said region of said one conductivity and said conductive material.
10. A method according to claim 6 , further comprising forming a region of another conductivity between each base region and said region of said one conductivity, said region of another conductivity extending to a depth below said base region.
11. A method according to claim 6 , further comprising a trench on each side of said region of said one conductivity between said base regions, each trench having an oxide formed on its sidewalls and containing a conductive material.