Method for depositing nanolaminate thin films on sensitive surfaces
The present method provides tools for growing conformal metal nitride, metal carbide and metal thin films, and nanolaminate structures incorporating these films, from aggressive chemicals. The amount of corrosive chemical compounds, such as hydrogen halides, is reduced during the deposition of transition metal, transition metal carbide and transition metal nitride thin films on various surfaces, such as metals and oxides. Getter compounds protect surfaces sensitive to hydrogen halides and ammonium halides, such as aluminum, copper, silicon oxide and the layers being deposited, against corrosion. Nanolaminate structures ( 20 ) incorporating metal nitrides, such as titanium nitride ( 30 ) and tungsten nitride ( 40 ), and metal carbides, and methods for forming the same, are also disclosed.
1. A method of depositing a material on a substrate in a reaction space, the substrate including a surface susceptible to halide attack, the method comprising providing alternated pulses of reactants in a plurality of deposition cycles, each cycle comprising:
supplying a first reactant to chemisorb no more than about one monolayer of a halide-terminated species over the surface;
removing excess first reactant and reaction by-product from the reaction space; and
gettering halides from the monolayer by exposure to a boron compound prior to repeating the cycle.
2. The method of claim 1 , wherein the material is a metal nitride.
3. The method of claim 1 , wherein the material is a metal carbide.
4. The method of claim 1 , wherein the first reactant comprises a metal halide.
5. The method of claim 1 , further comprising supplying a second reactant to react with the species after gettering halides.
6. The method of claim 5 , wherein the second reactant is a hydrogen bearing reactant.
7. The method of claim 5 , wherein the second reactant comprises a source of nitrogen and the material comprises a transition metal nitride.
8. The method of claim 5 , wherein the second reactant is ammonia.
9. The method of claim 1 , further comprising supplying a carbon source to react with the species and the material comprises a transition metal carbide.
10. The method of claim 1 , wherein the material comprises a thin film within a nanolaminate stack.
11. The method of claim 10 , wherein the nanolaminate stack is a diffusion barrier in an integrated circuit.
12. The method of claim 1 , wherein the surface comprises a material selected from the group consisting of aluminum, copper, silicon, silicon oxide, coated silicon, low-k materials, transition metal nitrides, metal oxides, and silicon nitride.
13. The method of claim 1 , wherein the surface comprises copper.
14. The method of claim 1 , wherein gettering comprises reducing.
15. The method of claim 1 , wherein the boron compound comprises triethyl boron (TEB).
16. A method for depositing tantalum nitride on a substrate in a reaction space, the method comprising providing alternating pulses of reactants in a plurality of deposition cycles, each cycle comprising:
supplying TaF 5 to chemisorb no more than about one monolayer over the surface;
removing excess TaF 5 ;
supplying a nitrogen containing reactant; and
removing excess nitrogen containing reactant,
wherein the substrate comprises a surface comprising a material selected from the group consisting of aluminum, copper, silicon oxide, silicon, silicon nitride and low-k materials.
17. The method of claim 16 , wherein the nitrogen containing reactant is selected from the group consisting of ammonia, nitrogen radicals and excited species of nitrogen.
18. The method of claim 17 , wherein the nitrogen containing reactant is ammonia.
19. The method of claim 16 , wherein the surface comprises copper.