Selective film formation using self-assembled monolayer
A film forming method includes: a preparation process of preparing a substrate having a surface from which a first film without containing silicon and a second film are exposed; a first film formation process of forming a self-assembled monolayer, which has a fluorine-containing functional group and inhibits formation of a third film containing silicon, on the first film; a second film formation process of forming the third film on the second film; a modification process of decomposing the self-assembled monolayer by plasma using a gas containing hydrogen and nitrogen while maintaining a temperature of the substrate to be 70 degrees C. or lower, so that a side portion of the third film, which is formed in a vicinity of the self-assembled monolayer, is modified into ammonium fluorosilicate by active species contained in the decomposed self-assembled monolayer; and a removal process of removing the ammonium fluorosilicate.
1 . A film forming method of selectively forming a film on a substrate, comprising:
a preparation process of preparing the substrate having a surface from which a first film without containing silicon and a second film are exposed;
a first film formation process of forming a self-assembled monolayer on the first film by supplying a compound for forming the self-assembled monolayer to the substrate, wherein the compound has a fluorine-containing functional group and the self-assembled monolayer inhibits formation of a third film containing silicon;
a second film formation process of forming the third film on the second film;
a modification process of decomposing the self-assembled monolayer by plasma using a gas containing hydrogen and nitrogen while maintaining a temperature of the substrate to be 70 degrees C. or lower, and modifying a side portion of the third film, which is formed in a vicinity of the self-assembled monolayer, into ammonium fluorosilicate by active species contained in the decomposed self-assembled monolayer; and
a first removal process of removing the ammonium fluorosilicate.
2 . The film forming method of claim 1 , wherein in the first removal process, the ammonium fluorosilicate formed on the side portion of the third film is removed by heating the substrate to a temperature within a range of 100 degrees C. or higher and 250 degrees C. or lower.
3 . The film forming method of claim 2 , wherein the first film formation process, the second film formation process, the modification process, and the first removal process are repeated two or more times in this order.
4 . The film forming method of claim 3 , wherein the first film is a metal film without containing silicon,
wherein the second film is an insulating film, and
wherein the third film is a dielectric film containing silicon.
5 . The film forming method of claim 4 , wherein the first film is formed of copper, cobalt, ruthenium, or tungsten,
wherein the second film is a silicon oxide film, a silicon nitride film, a silicon carbide, a carbon-containing silicon oxide film, a carbon-containing silicon nitride film, or a carbon-nitrogen-containing silicon oxide film, and
wherein the third film is a silicon oxide film or an aluminum-containing silicon oxide film.
6 . The film forming method of claim 5 , wherein the compound for forming the self-assembled monolayer further has a bonding functional group adsorbed to a surface of the first film.
7 . The film forming method of claim 6 , wherein the compound for forming the self-assembled monolayer is a thiol-based compound.
8 . The film forming method of claim 7 , further comprising a second removal process, which is executed before the first film formation process and removes a layer containing impurities formed on the first film by exposing the surface of the substrate to plasma.
9 . The film forming method of claim 1 , wherein in the first removal process, the ammonium fluorosilicate formed on the side portion of the third film is removed by exposing the substrate to plasma.
10 . The film forming method of claim 1 , wherein the first film formation process, the second film formation process, the modification process, and the first removal process are repeated two or more times in this order.
11 . The film forming method of claim 1 , wherein after the first removal process is executed, the first film formation process, the modification process, and the first removal process are executed one or more times in this order.
12 . The film forming method of claim 1 , wherein the first film is a metal film without containing silicon,
wherein the second film is an insulating film, and
wherein the third film is a dielectric film containing silicon.
13 . The film forming method of claim 1 , wherein the first film is formed of copper, cobalt, ruthenium, or tungsten,
wherein the second film is a silicon oxide film, a silicon nitride film, a silicon carbide, a carbon-containing silicon oxide film, a carbon-containing silicon nitride film, or a carbon-nitrogen-containing silicon oxide film, and
wherein the third film is a silicon oxide film or an aluminum-containing silicon oxide film.
14 . The film forming method of claim 1 , wherein the compound for forming the self-assembled monolayer further has a bonding functional group adsorbed to a surface of the first film.
15 . The film forming method of claim 14 , wherein the compound for forming the self-assembled monolayer is a thiol-based compound.
16 . The film forming method of claim 1 , further comprising a second removal process, which is executed before the first film formation process and removes a layer containing impurities formed on the first film by exposing the surface of the substrate to plasma.