Semiconductor device manufacturing method
A semiconductor device manufacturing method of embodiments includes: performing first ion implantation for implanting aluminum into a silicon carbide layer with a first dose amount; performing first heat treatment at a temperature equal to or more than 1600° C.; performing first etching process for etching a surface of the silicon carbide layer in an atmosphere containing plasma generated from a gas containing halogen and oxygen; performing second etching process for etching the surface in an atmosphere containing hydrogen plasma or atomic hydrogen; forming a silicon oxide film on the surface; and forming a gate electrode on the silicon oxide film.
1 . A semiconductor device manufacturing method, comprising:
performing a first ion implantation implanting aluminum into a silicon carbide layer with a first dose amount;
performing a first heat treatment at a temperature equal to or more than 1600° C.;
performing a first etching process etching a surface of the silicon carbide layer in an atmosphere containing plasma generated from a gas containing halogen and oxygen;
performing a second etching process etching the surface in an atmosphere containing hydrogen plasma or atomic hydrogen;
forming a silicon oxide film on the surface; and
forming a gate electrode on the silicon oxide film.
2 . The semiconductor device manufacturing method according to claim 1 , further comprising:
performing a second ion implantation implanting carbon into the silicon carbide layer with a second dose amount before the performing the first heat treatment, the second dose amount being equal to or more than ten times the first dose amount.
3 . The semiconductor device manufacturing method according to claim 1 ,
wherein the first etching process is performed by using an etching apparatus in which a plasma generation unit and an etching processing unit are separated from each other.
4 . The semiconductor device manufacturing method according to claim 1 ,
wherein the first etching process is isotropic etching process.
5 . The semiconductor device manufacturing method according to claim 1 ,
wherein, in the first etching process, the gas contains perfluorocarbon.
6 . The semiconductor device manufacturing method according to claim 1 ,
wherein the first etching process is performed at a temperature equal to or more than 20° C. and equal to or less than 1300° C.
7 . The semiconductor device manufacturing method according to claim 1 ,
wherein the second etching process is performed at a temperature equal to or more than 20° C. and equal to or less than 300° C.
8 . The semiconductor device manufacturing method according to claim 1 ,
wherein, in the first etching process, the surface is etched by 5 nm or more and 50 nm or less.
9 . The semiconductor device manufacturing method according to claim 1 ,
wherein, in the second etching process, the surface is etched by 5 nm or more and 25 nm or less.
10 . The semiconductor device manufacturing method according to claim 1 ,
wherein the surface has an inclination equal to or more than 0° and equal to or less than 8° with respect to an a-face or an inclination equal to or more than 0° and equal to or less than 8° with respect to an m-face.
11 . The semiconductor device manufacturing method according to claim 1 , further comprising:
forming a trench in the silicon carbide layer before the performing the first etching process after the performing the first heat treatment, and
wherein the surface is a sidewall surface of the trench.
12 . A semiconductor device manufacturing method, comprising:
forming a p-type silicon carbide film on an n-type silicon carbide layer using an epitaxial growth method;
performing a first etching process etching a surface of the silicon carbide film in an atmosphere containing plasma generated from a gas containing halogen and oxygen;
performing a second etching process etching the surface in an atmosphere containing hydrogen plasma or atomic hydrogen;
forming a silicon oxide film on the surface; and
forming a gate electrode on the silicon oxide film.
13 . The semiconductor device manufacturing method according to claim 12 ,
wherein the first etching process is performed by using an etching apparatus in which a plasma generation unit and an etching processing unit are separated from each other.
14 . The semiconductor device manufacturing method according to claim 12 ,
wherein the first etching process is isotropic etching process.
15 . The semiconductor device manufacturing method according to claim 12 ,
wherein, in the first etching process, the gas contains perfluorocarbon.
16 . The semiconductor device manufacturing method according to claim 12 ,
wherein the first etching process is performed at a temperature equal to or more than 20° C. and equal to or less than 1300° C.
17 . The semiconductor device manufacturing method according to claim 12 ,
wherein the second etching process is performed at a temperature equal to or more than 20° C. and equal to or less than 300° C.
18 . The semiconductor device manufacturing method according to claim 12 ,
wherein, in the first etching process, the surface is etched by 5 nm or more and 50 nm or less.
19 . The semiconductor device manufacturing method according to claim 12 ,
wherein, in the second etching process, the surface is etched by 5 nm or more and 25 nm or less.
20 . The semiconductor device manufacturing method according to claim 12 ,
wherein the surface has an inclination equal to or more than 0° and equal to or less than 8° with respect to an a-face or an inclination equal to or more than 0° and equal to or less than 8° with respect to an m-face.
21 . The semiconductor device manufacturing method according to claim 12 , further comprising:
forming a trench in the silicon carbide layer before the performing the first etching process after the performing the first heat treatment, and
wherein the surface is a sidewall surface of the trench.