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US 8,071,482 B2Granted
Manufacturing method of a silicon carbide semiconductor device
AssigneeFuji Electric Co., Ltd.
InventorYasuyuki Kawada
Life of this patent
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Abstract
A manufacturing method for a silicon carbide semiconductor device is disclosed. It includes an etching method in which an Al film and Ni film are laid on an SiC wafer in this order and wet-etched, whereby a two-layer etching mask is formed in which Ni film portions overhang Al film portions. Mesa grooves are formed by dry etching by using this etching mask.
Claims8
A manufacturing method of a silicon carbide semiconductor device, comprising:
- depositing an Al film and an Ni film in that order to form a metal lamination film on a SiC semiconductor substrate;
- etching the metal lamination film to produce a metal lamination mask in which Ni film portions cover and overhang Al film portions;
- and then
- etching a mesa groove at least 10 μm deep in the silicon carbide substrate using an induction-coupled plasma obtained by ionizing a mixed gas of SF6, O2, and Ar gases, under conditions that the SF6, O2, and Ar gases are caused to flow at flow rates of 26% to 35%, 7.5% to 8.5%, and 58% to 65% with respect to a total gas flow rate, respectively, wherein the temperature of the silicon carbide semiconductor substrate is 30° C.±5° C. and pressure is kept at 3 Pa or more.
1 more element
A manufacturing method of a silicon carbide semiconductor device, comprising:
- depositing an Al film and an Ni film in that order to form a metal lamination film on a SiC semiconductor substrate;
- etching the metal lamination film to produce a metal lamination mask in which Ni film portions cover and overhang Al film portions;
- and then
- etching a mesa groove at least 10 μm deep in the silicon carbide substrate using an induction-coupled plasma obtained by ionizing a mixed gas of SF6, O2, and Ar gases, under conditions that the SF6, O2, and Ar gases are caused to flow at flow rates of 26% to 35%, 7.5% to 8.5%, and 58% to 65% with respect to a total gas flow rate, respectively, wherein the temperature of the silicon carbide semiconductor substrate is 30° C.±5° C. and pressure is kept at 3 Pa or more,
- wherein overhanging portions of the Ni film remain after the mesa groove is etched.
2 more elements
A manufacturing method of a silicon carbide semiconductor device, comprising:
- depositing an Al film directly on a SiC semiconductor substrate;
- depositing an Ni film on the deposited Al flim, to form a metal lamination film;
- etching the metal lamination film to produce a metal lamination mask in which Ni film portions cover and overhang Al film portions;
- and then
- etching a mesa groove at least 10 μm deep in the silicon carbide substrate using an induction-coupled plasma obtained by ionizing a mixed gas of SF6, O2, and Ar gases, under conditions that the SF6, O2, and Ar gases are caused to flow at flow rates of 26% to 35%, 7.5% to 8.5%, and 58% to 65% with respect to a total gas flow rate, respectively, wherein the temperature of the silicon carbide semiconductor substrate is 30° C.±5° C. and pressure is kept at 3 Pa or more.
2 more elements
Dependencies are inferred from the claim text.