Low dielectric constant film material, film and semiconductor device using such material
View Patent ↗A low dielectric film forming material contains siloxane resin and polycarbosilane dissolved in solvent. By using this solution, a low dielectric film is formed which contains siloxane resin and polycarbosilane bonded to the siloxane resin. Material of a low dielectric film is provided which is suitable for inter-level insulating film material. A semiconductor device is also provided which has a low dielectric constant film and high reliability.
1. A semiconductor device comprising:
a semiconductor substrate;
a first film formed on a surface of said semiconductor substrate and made of a first silica-containing porous material; and
a second film in direct contact with said first film and made of a second silica-containing porous material, the second silica-containing porous material having an etching rate different from an etching rate or the first silica-containing porous material under a same etching condition;
wherein the first and second silica-containing porous materials contain siloxane resin expressed by a general chemical formula of:
(R 10 to R 12 represent hydrogen, oxygen or a monovalent hydrocarbon group, n 1 represents an integer of 5 to 200, and X represents hydrogen or silicon), or:
(R 13 to R 16 represent hydrogen, fluorine or a monovalent hydrocarbon group, n 2 is an integer of 5 to 100, wherein at least one of R 13 to R 16 is hydrogen);
wherein for the first silica-containing porous material, at least one of R 10 to R 12 is a phenyl group or a hydrocarbon group having two to five carbon atoms, or at least one of R 13 to R 16 is a phenyl group or a hydrocarbon group having two to five carbon atoms, and for the second silica-containing porous material, none of R 10 to R 12 are a hydrocarbon group having two or more carbon atoms or none of R 13 to R 16 are a hydrocarbon group having two or more carbon atoms.
2. The semiconductor device according to claim 1 , wherein a faster one of etching rates of the first and second silica-containing porous materials is two times or more faster than a slower one.
3. The semiconductor device according to claim 2 , wherein the first and second silica-containing porous materials contain siloxane resin expressed by a general chemical formula of:
(R 10 to R 12 represent hydrogen, oxygen or a monovalent hydrocarbon group, n 1 represents an integer of 5 to 200, and X represents hydrogen or silicon), or:
(R 13 to R 16 represent hydrogen, fluorine or a monovalent hydrocarbon group, n 2 is an integer of 5 to 100, wherein at least one of R 13 to R 16 is hydrogen).
4. The semiconductor device according to claim 1 , wherein an etching rate of the second silica-containing porous material is faster than an etching rate of the first silica-containing porous material, and the semiconductor device further comprises:
a trench formed in said second film and having a depth greater than a thickness of said second film;
a via hole formed through said first film, said via hole being partially overlapped by said trench; and
a conductive wiring line burying an inside of said via hole and trench.
5. The semiconductor device according to claim 1 , wherein an etching rate of the second silica-containing porous material is faster than an etching rate of the first silica-containing porous material, and the semiconductor device further comprises:
a trench formed said second film and having a depth greater than a thickness of said second film;
a via bole formed through said first film, said via hole being partially overlapped by said trench; and
a conductive wiring line burying an inside of said via hole and trench.
6. A semiconductor device comprising:
a semiconductor substrate;
a first film formed on a surface of said semiconductor substrate and made of a first silica-containing porous material; and
a second film in direct contact with said first film and made of a second silica-containing porous material,
wherein the first and second silica-containing porous materials contain siloxane resin expressed by a general chemical formula of:
(R 10 to R 12 represent hydrogen, oxygen or a monovalent hydrocarbon group, n 1 represents an integer of 5 to 200, and X represents hydrogen or silicon), or:
(R 13 to R 16 represent hydrogen, fluorine or a monovalent hydrocarbon group, n 2 is an integer of 5 to 100, wherein at least one of R 13 to R 16 is hydrogen),
for the first silica containing porous material, at least one of R 10 to R 12 is a phenyl group or a hydrocarbon group having two to five carbon atoms or at least one of R 13 to R 16 is a phenyl group or a hydrocarbon group having two to five carbon atoms, and for the second silica-containing porous material, none of R 10 to R 12 are a hydrocarbon group having two or more carbon atoms or none of R 13 to R 16 are a hydrocarbon group having two or more carbon atoms.