Manufacturing method of semiconductor device
View Patent ↗In forming a high density plasma oxide film, a projection shaped like the mesa, the peaked roof, the cone or the like is formed on an element formation region. This projection gives rise to a problem of producing a polishing scar when the CMD (Chemical Mechanical Polishing) with a ceria slurry is performed. A film having a polishing rate equivalent to the one of the high density plasma oxide film is formed on the high density plasma oxide film to reinforce a projection in the shape of a triangular prism, a cone or such, and, thereafter, the polishing is carried out, using a ceria slurry. In another method, after the first CMP polishing is performed, using a silica slurry containing grains of small particle size which make no aggregation, the second CMP polishing is performed, using a ceria slurry.
1. A method of manufacturing a semiconductor device, which comprises:
depositing, on a basic substance surface with a difference in level, a first film through an anisotropic growth;
forming, through an isotropic growth, a second film, having a polishing rate equivalent to or less than a polishing rate of said first film, to reinforce a projection formed on said first film; and
polishing said first film and said second film using a ceria slurry.
2. The method of manufacturing a semiconductor device according to claim 1 , wherein said difference in level comprises a trench.
3. The method of manufacturing a semiconductor device according to claim 1 , wherein said difference in level comprises an interconnection.
4. The method of manufacturing a semiconductor device according to claim 1 , wherein a stopper film which is to act as a polishing stopper, having a polishing rate less than a polishing rate of said first film, is formed on an upper level section constituting said difference in level.
5. The method of manufacturing a semiconductor device according to claim 4 , wherein said first film and said second film both comprise oxide films and said stopper film comprises a nitride film.
6. The method of manufacturing a semiconductor device according to claim 1 , wherein said first film comprises a film formed by a high density plasma Chemical Vapor Deposition method.
7. The method of manufacturing a semiconductor device according to claim 1 , wherein said second film comprises a film formed by one of an atmospheric chemical vapor deposition method, a low pressure chemical vapor deposition method, and a plasma chemical vapor deposition method.
8. The method of claim 1 , further comprising polishing said first film and said second film using a slurry whose grains do not make aggregation before said polishing said first film and said second film using said ceria slurry.
9. The method of claim 1 , wherein the polishing rate of the first film and the second film are within twenty percent of each other.
10. The method of claim 1 , wherein a thickness of said second film is not less than about 100 nm.
11. The method of claim 1 , wherein a thickness of said second film is not greater than about 400 nm.
12. The method of claim 1 , further comprising forming a stopper film on an upper level section constituting said difference in level.
13. The method of claim 12 , wherein said first film and said second film both comprise oxide films and said stopper film comprises a nitride film.
14. The method of claim 1 , wherein said isotropically growing of said second film comprises forming said second film by at least one of an atmospheric chemical vapor deposition method, a low pressure chemical vapor deposition method, and a plasma chemical vapor deposition method.
15. A method of manufacturing a semiconductor device, the method comprising:
anisotropically growing a first film on a substance surface having differences in level;
isotropically growing a second film which reinforces a projection on said first film, wherein said second film has a polishing rate that is equal to or less than a polishing rate of said first film; and
polishing said first film and said second film using a ceria slurry.
16. The method of claim 15 , wherein said difference in level comprises a trench.
17. The method of claim 15 , wherein said difference in level comprises an interconnection.
18. The method of claim 15 , wherein said anisotropically growing of said first film comprises a high density plasma chemical vapor deposition method.