Methods for gapfill in high aspect ratio structures
Methods for seam-less gapfill comprising sequentially depositing a film with a seam, reducing the height of the film to remove the seam and repeating until a seam-less film is formed. Some embodiments include optional film doping and film treatment (e.g., ion implantation and annealing).
1. A processing method comprising:
providing a substrate surface having an opening formed by at least one feature, the at least one feature, the at least one feature extending a depth from the substrate surface to a bottom surface, the at least one feature having a width defined by a first sidewall and a second sidewall;
forming a first quantity of a film on the substrate surface and the first sidewall, second sidewall and bottom surface of the at least one feature in a first deposition sequence, the first quantity of the film having a seam located within the width of the at least one feature wherein a bottom of the seam being at a first distance from the bottom surface of the at least one feature; and
reducing a height of the first quantity of the film to less than the first distance to remove at least some of the first quantity of the film and to completely remove the seam.
2. The method of claim 1 , further comprising forming a second quantity of the film on the substrate surface in a second deposition sequence after reducing the height of the first quantity of the film so that the second quantity of the film forms with a seam located within the width of the feature at a second distance from the bottom surface of the feature, the second distance being greater than the first distance.
3. The method of claim 2 , further comprising reducing the height of the second quantity of the film to less than the second distance to remove the seam.
4. The method of claim 3 , further comprising repeating forming quantities of the film with a seam therein and reducing the height of the quantities of the film to remove the seam, each formation of the seam having a greater distance from the bottom surface than a previous seam until the at least one feature has substantially no seam.
5. The method of claim 1 , further comprising doping the film with a dopant.
6. The method of claim 5 , wherein doping the film occurs with formation of the film.
7. The method of claim 5 , wherein doping the film is performed sequentially with formation of the film.
8. The method of claim 1 , wherein reducing the height of the film comprises etching the film.
9. The method of claim 8 , wherein etching the film comprises exposing the film to an etch chemistry comprising one or more of NF 3 , CI 2 , HBr, C 4 F 6 , C 2 F 4 , H 2 , Ar, He or N 2 .
10. The method of claim 1 , further comprising treating the film.
11. The method of claim 10 , wherein treating the film comprises annealing the film.
12. The method of claim 1 , wherein the film is conformal.
13. The method of claim 1 , wherein the at least one feature has an aspect ratio greater than or equal to 10:1.