Method for manufacturing semiconductor device, semiconductor device, inverter circuit, drive device, vehicle, and elevator
A method for manufacturing a semiconductor device of an embodiment includes performing first ion implantation of implanting aluminum (Al) into a silicon carbide layer in a first projected range and a first dose amount, performing second ion implantation of implanting carbon (C) into the silicon carbide layer in a second projected range and a second dose amount which is a dose amount equal to or more than 10 times the first dose amount, performing a first heat treatment of 1600° C. or more, performing an oxidation treatment of oxidizing the silicon carbide layer, performing an etching process of etching the silicon carbide layer in an atmosphere containing a hydrogen gas, forming a silicon oxide film on the silicon carbide layer, and forming a gate electrode on the silicon oxide film.
1 . A method for manufacturing a semiconductor device, comprising:
performing first ion implantation of implanting aluminum (Al) into a first portion of a silicon carbide layer in a first projected range and a first dose amount, the silicon carbide layer including a first region and a second region, and the second region is formed on the first region by an epitaxial growth method;
performing second ion implantation of implanting carbon (C) into the first portion of the silicon carbide layer in a second projected range and a second dose amount, the second dose amount being equal to or more than 10 times the first dose amount, after performing the first ion implantation;
performing a first heat treatment of 1600° C. or more, after the performing the second ion implantation;
performing an oxidation treatment of oxidizing the silicon carbide layer, after the performing the first heat treatment;
performing an etching process of etching the silicon carbide layer in an atmosphere containing a hydrogen gas, after the performing the oxidation treatment;
forming a silicon oxide film on an etched surface of the silicon carbide layer, after the performing the etching process; and
forming a gate electrode on the silicon oxide film,
wherein the silicon carbide layer is etched by 10 nm or more during the etching process,
a temperature of the etching process is equal to or more than 1300° C. and equal to or less than 1500° C., and
none of nickel (Ni), palladium (Pd), and platinum (Pt) is implanted into the first portion.
2 . The method for manufacturing a semiconductor device according to claim 1 , wherein the silicon carbide layer is etched by 15 nm or more during the etching process.
3 . The method for manufacturing a semiconductor device according to claim 1 , wherein the silicon carbide layer is etched by 25 nm or more during the etching process.
4 . The method for manufacturing a semiconductor device according to claim 1 , further comprising:
forming a carbon film on the silicon carbide layer after the performing first ion implantation before the performing the first heat treatment, wherein
the oxidation treatment is an ashing treatment of removing the carbon film in oxygen plasma.
5 . The method for manufacturing a semiconductor device according to claim 1 , wherein the oxidation treatment is a thermal oxidation treatment.
6 . The method for manufacturing a semiconductor device according to claim 1 , wherein the oxidation treatment is a deposition treatment of depositing an insulating film containing oxygen on the silicon carbide layer.
7 . The method for manufacturing a semiconductor device according to claim 1 , wherein the first dose amount is equal to or less than 1×10 14 cm −2 .
8 . The method for manufacturing a semiconductor device according to claim 1 , wherein the second dose amount is equal to or more than 1×10 15 cm −2 .
9 . The method for manufacturing a semiconductor device according to claim 1 , wherein the first projected range and the second projected range are equal to or less than 0.6 μm.
10 . The method for manufacturing a semiconductor device according to claim 1 , wherein the second projected range is equal to or more than 80% and equal to or less than 120% of the first projected range.
11 . The method for manufacturing a semiconductor device according to claim 1 , wherein the first ion implantation and the second ion implantation are performed in a same region of the silicon carbide layer.
12 . The method for manufacturing a semiconductor device according to claim 1 , further comprising:
performing a second heat treatment in an atmosphere containing nitrogen (N) before or after the forming the silicon oxide film, and before the forming the gate electrode.