Silicon carbide semiconductor device and method of manufacturing silicon carbide semiconductor device
AssigneeFuji Electric Co., Ltd.
InventorsMakoto UTSUMI, Akimasa KINOSHITA, Naoyuki OHSE
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Abstract
A semiconductor device, including: a semiconductor substrate containing silicon carbide; a semiconductor device element provided on the semiconductor substrate; a poly-silicon layer provided on a main surface of the semiconductor substrate via an insulating film, the poly-silicon layer including a p-type first poly-silicon layer and an n-type second poly-silicon layer forming a pn junction therebetween; and a diode formed by the pn junction. The second poly-silicon layer contains phosphorus or antimony as a donor, and is so configured that a sheet resistance thereof at 25 degrees C is not less than 80 Ω/□ but not more than 400 Ω/□.
Claims20
A semiconductor device comprising:
- a semiconductor substrate containing silicon carbide;
- a semiconductor device element provided on the semiconductor substrate;
- a poly-silicon layer provided on a main surface of the semiconductor substrate via an insulating film, the poly-silicon layer including a p-type first poly-silicon layer and an n-type second poly-silicon layer forming a pn junction therebetween;
- and
- a diode formed by the pn junction, wherein
- the second poly-silicon layer contains phosphorus or antimony as a donor, and is so configured that a sheet resistance thereof at 25 degrees C is not less than 80 Ω/□ but not more than 400 Ω/□.
A semiconductor device, comprising:
- a semiconductor substrate containing silicon carbide;
- a semiconductor device element provided on the semiconductor substrate,
- a plurality of poly-silicon layers provided, apart from one another, on a main surface of the semiconductor substrate via an insulating film, each poly-silicon layer including a p-type first poly-silicon layer and an n-type second poly-silicon layer forming a pn junction therebetween;
- and
- a plurality of diodes formed by the pn junctions in the plurality of the poly-silicon layers, the plurality of diodes including a first diode and a second diode different from each other, wherein
- said first diode is either connected in antiparallel to the second diode, or connected between a lowest potential point of the semiconductor device element and a cathode of the second diode.
A method of manufacturing a semiconductor device, the method comprising:
- preparing a semiconductor substrate containing silicon carbide;
- forming in the semiconductor substrate a semiconductor device element;
- forming a poly-silicon layer on a main surface of the semiconductor substrate via an insulating film;
- ion-implanting a p-type dopant into the poly-silicon layer, thereby forming a first poly-silicon layer;
- ion-implanting an n-type dopant into the poly-silicon layer, thereby forming a second poly-silicon layer, the first poly-silicon layer and the second poly-silicon layer forming a pn junction therebetween, to thereby form a diode;
- and
- performing a heat treatment thereby activating the p-type dopant and the n-type dopant as an acceptor and a donor, respectively, wherein
- the ion-implanting the n-type dopant includes:
- ion-implanting phosphorus with a net dose amount of not less than 1.0×1015/cm2 but not more than 1.0×1016/cm2 or
- ion-implanting antimony with a net dose amount of not less than 1.5×1015/cm2 but not more than 2.5×1015/cm2.
Dependencies are inferred from the claim text.