Substrate processing method and substrate processing apparatus
A substrate processing method according to the present disclosure includes: preparing a substrate having (a) an etching film, (b) a mask film formed on the etching film and having a sidewall that defines an opening on the etching film, and (c) a protective film formed to surround the opening on the sidewall of the mask film and containing an element selected from the group consisting of boron, phosphorus, sulfur, and tin; and etching the etching film by using the protective film and the mask film as a mask.
1 . A substrate processing method, comprising:
preparing a substrate having (a) an etching film, (b) a mask film formed on the etching film and having a sidewall that defines an opening on the etching film, and (c) a protective film formed to surround the opening on the sidewall of the mask film and containing an element selected from the group consisting of boron, phosphorus, sulfur, and tin, wherein the preparing the substrate includes:
forming the protective film;
measuring one or both of a dimension and a shape of the opening surrounded by the protective film; and
trimming a thickness of a portion of the protective film formed on the sidewall based on one or both of the dimension and the shape; and
etching the etching film by using the protective film and the mask film as a mask.
2 . The substrate processing method according to claim 1 , wherein the preparing the substrate further includes measuring one or both of the dimension and the shape of the opening surrounded by the trimmed protective film.
3 . The substrate processing method according to claim 2 , wherein the preparing the substrate further includes one of the forming the protective film and the trimming based on one or both of the dimension and the shape of the opening surrounded by the trimmed protective film.
4 . The substrate processing method according to claim 1 , wherein
the forming the protective film includes forming a precursor layer on the sidewall of the mask film by using a first processing gas, and forming the protective film from the precursor layer by using a second processing gas, and
the first processing gas or the second processing gas contains the element.
5 . The substrate processing method according to claim 1 , wherein the preparing the substrate includes forming the protective film by a CVD method.
6 . The substrate processing method according to claim 1 , wherein the preparing the substrate further includes modifying the protective film such that the protective film contains the element more on a surface of the protective film than in an interior of the protective film.
7 . The substrate processing method according to claim 6 , wherein the modifying the protective film includes causing the surface of the protective film to react with a processing gas containing the element to convert the surface of the protective film into a film containing the element or a film containing a compound containing the element.
8 . The substrate processing method according to claim 7 , wherein
the forming the protective film includes forming a carbon containing film or a silicon containing film as the protective film, and
the modifying the protective film includes causing a surface of the carbon containing film or the silicon containing film to react with the processing gas containing the element to convert the carbon containing film or the silicon containing film into the film containing the element or the film containing the compound containing the element.
9 . The substrate processing method according to claim 7 , wherein the compound containing the element is boron oxide, boron nitride, boron carbide, silicon boride, or an organic boron compound.
10 . The substrate processing method according to claim 7 , wherein the compound containing the element is phosphoric acid, polyphosphoric acid, a phosphate salt, a phosphate ester, a phosphorus oxide, or a phosphorus nitride.
11 . The substrate processing method according to claim 7 , wherein the compound containing the element is a tin oxide, a tin nitride, a tin phosphide, a tin sulfide, or a tin halide.
12 . The substrate processing method according to claim 1 , wherein the opening has a hole shape or a linear shape in a plan view of the substrate.
13 . The substrate processing method according to claim 1 , wherein the preparing the substrate includes modifying the protective film such that the trimmed protective film contains the element more on a surface of the protective film than in an interior of the protective film.
14 . The substrate processing method according to claim 13 , wherein the modifying the protective film includes causing the surface of the trimmed protective film to react with a processing gas containing the element to convert the surface of the trimmed protective film into a film containing the element or a film containing a compound containing the element.