Selective film formation for raised and recessed features using deposition and etching processes
Embodiments of the invention provide a processing method for selective film formation for raised and recessed features using deposition and etching processes. According to one embodiment, the method includes providing a substrate having a recessed feature with a sidewall and a bottom portion, and depositing a film in the recessed feature and on a field area around the opening of the recessed feature, where the film is non-conformally deposited with a greater film thickness on the bottom portion than on the sidewall and the field area. The method further includes etching the film in an atomic layer etching (ALE) process in the absence of a plasma, where the etching thins the film on the bottom portion and removes the film from the sidewall and the field area, and repeating the depositing and the etching at least once to increase the film thickness of on the bottom portion.
1. A substrate processing method, comprising:
providing a substrate having a recessed feature with a sidewall and a bottom portion;
depositing a film in the recessed feature and on a field area around the opening of the recessed feature, wherein the film is non-conformally deposited with a greater film thickness on the bottom portion than on the sidewall and the field area;
etching the film in an atomic layer etching (ALE) process in the absence of a plasma, wherein the etching thins the film on the bottom portion and removes the film from the sidewall and the field area; and
repeating the depositing and the etching at least once to increase the film thickness on the bottom portion.
2. The method of claim 1 , wherein the film includes a metal oxide film.
3. The method of claim 2 , wherein the ALE process includes sequential gas exposures of trimethylaluminum (TMA) and HF.
4. The method of claim 2 , wherein the metal oxide film is selected from the group consisting of HfO 2 , ZrO 2 , TiO 2 , Al 2 O 3 , and a combination thereof.
5. The method of claim 1 , wherein the film is selected from the group consisting of a metal oxide film, a metal nitride film, a metal oxynitride film, a metal silicate film, and a combination thereof.
6. The method of claim 1 , further comprising
following the repeating, overfilling the recessed feature with excess film; and
removing the excess film from the field area and the overfilled recessed feature in a planarization process.
7. The method of claim 1 , wherein the bottom portion and the sidewall contain different materials.
8. The method of claim 7 , wherein the different materials are selected from the group consisting of silicon, germanium, silicon germanium, a dielectric material, a metal, and a metal-containing material.
9. The method of claim 7 , wherein the depositing has different film nucleation rates on the different materials.
10. The method of claim 1 , wherein the bottom portion and the sidewall contain the same material.
11. The method of claim 10 , wherein the material is selected from the group consisting of silicon, germanium, silicon germanium, a dielectric material, a metal, and a metal-containing material.
12. The method of claim 1 , wherein the film includes a metal film.
13. The method of claim 1 , The method of claim 1 , wherein the film is selected from the group consisting of Cu, Al, Ta, Ru, TaN, TaC, and TaCN.
14. The method of claim 1 , wherein the repeating is performed until recessed feature is fully filled with the film.
15. A substrate processing method, comprising:
providing a substrate having a recessed feature with a sidewall and a bottom portion;
depositing a Ru metal film in the recessed feature and on a field area around the opening of the recessed feature, wherein the Ru metal film is non-conformally deposited with a greater film thickness on the bottom portion than on the sidewall and the field area;
etching the Ru metal film in an atomic layer etching (ALE) process in the absence of a plasma, wherein the etching removes the Ru metal film from the field area; and
repeating the depositing and the etching until the recessed feature is fully filled with the Ru metal film.
16. The method of claim 15 , wherein the bottom portion and the sidewall contain different materials.
17. The method of claim 16 , wherein the different materials are selected from the group consisting of silicon, germanium, silicon germanium, a dielectric material, a metal, and a metal-containing material.
18. The method of claim 16 , wherein the depositing has different film nucleation rates on the different materials.
19. The method of claim 15 , wherein the bottom portion and the sidewall contain the same material.
20. The method of claim 19 , wherein the material is selected from the group consisting of silicon, germanium, silicon germanium, a dielectric material, a metal, and a metal-containing material.