Method of densifying films in semiconductor device
Methods of densifying films, cross-linking films, and controlling the stress of films are provided herein. Methods include forming a removable film on a substrate comprising a material to be densified, and annealing the substrate to transfer stress from the removable film to the material and thereby densify the material. Some methods involve depositing a tensile capping layer on the material to be densified on a substrate and annealing the substrate at a temperature greater than about 450° C. Some methods include clamping the substrate including the material to be densified to a shaped pedestal using an electrostatic chuck to apply compressive stress to the material to be densified.
1. A method of densifying material in a recessed feature on a semiconductor substrate, the method comprising:
receiving the semiconductor substrate comprising the recessed feature and a seam, the recessed feature filled with the material to be densified;
forming a removable film over the material to be densified in the recessed feature on the substrate, the substrate having a diameter selected from the group consisting of 200 mm, 300 mm, and 450 mm; and
annealing the substrate to transfer stress from the removable film to the material and densify the material,
wherein the removable film is selected from the group consisting of metal-containing nitrides, metal-containing oxides, silicon-containing nitrides, and silicon-containing carbides, and
wherein annealing the substrate comprises crosslinking the seam in the recessed feature.
2. The method of claim 1 , wherein the removable film is tensile.
3. The method of claim 2 , wherein annealing the substrate induces tensile stress in the removable film.
4. The method of claim 2 , wherein the annealing the substrate comprises heating the substrate at a temperature greater than at least about 450° C.
5. The method of claim 2 , wherein the tensile stress of the removable film is at least about 1 GPa.
6. The method of claim 1 , wherein the material to be densified is an oxide.
7. The method of claim 1 , further comprising after annealing the substrate, treating the substrate with ultraviolet radiation or plasma.
8. The method of claim 1 , wherein the material to be densified is a nitride or carbide.
9. The method of claim 1 , wherein the removable film is deposited to a thickness of at least about 1000 Å.
10. The method of claim 1 , further comprising removing the removable film.
11. The method of claim 1 , wherein the removable film is compressive.
12. The method of claim 11 , wherein annealing the substrate induces compressive stress in the removable film.
13. The method of claim 11 , wherein the removable film is deposited on the substrate housed in a furnace.
14. The method of claim 11 , further comprising forming a removable tensile film over the material to be densified prior to annealing the substrate.
15. The method of claim 1 , wherein annealing the substrate causes the semiconductor substrate and the removable film to be bowed.
16. A method of densifying material in a recessed feature on a semiconductor substrate, the method comprising:
receiving the semiconductor substrate comprising the recessed feature and a seam, the recessed feature filled with the material to be densified;
forming a removable compressive film on the backside of the semiconductor substrate, the semiconductor substrate having a diameter selected from the group consisting of 200 mm, 300 mm, and 450 mm; and
annealing the substrate to transfer stress from the removable compressive film to the material and densify the material,
wherein annealing the substrate comprises crosslinking a seam in the feature.