NMOS metal gate materials, manufacturing methods, and equipment using CVD and ALD processes with metal based precursors
Embodiments of the invention generally provide methods for depositing metal-containing materials and compositions thereof. The methods include deposition processes that form metal, metal carbide, metal silicide, metal nitride, and metal carbide derivatives by a vapor deposition process, including thermal decomposition, CVD, pulsed-CVD, or ALD. In one embodiment, a method for processing a substrate is provided which includes depositing a dielectric material having a dielectric constant greater than 10, forming a feature definition in the dielectric material, depositing a work function material conformally on the sidewalls and bottom of the feature definition, and depositing a metal gate fill material on the work function material to fill the feature definition, wherein the work function material is deposited by reacting at least one metal-halide precursor having the formula MX Y , wherein M is tantalum, hafnium, titanium, and lanthanum, X is a halide selected from the group of fluorine, chlorine, bromine, or iodine, and y is from 3 to 5.
1. A method for processing a substrate comprising:
depositing a dielectric material having a dielectric constant greater than 10;
forming a feature definition in the dielectric material;
depositing a work function material conformally on the sidewalls and bottom of the feature definition; and
depositing a metal gate fill material on the work function material to fill the feature definition, wherein the work function material is deposited by reacting at least one metal-halide precursor having the formula MX Y , wherein M is tantalum, hafnium, titanium, and lanthanum, X is selected from the group of fluorine, chlorine, bromine, or iodine, and y is from 3 to 5, wherein the metal gate fill material and the work function material are the same material.
2. The method of claim 1 , wherein the work function material is a silicide.
3. The method of claim 1 , wherein the work function material is a boride.
4. The method of claim 1 , wherein the work function material is an aluminide.
5. The method of claim 1 , wherein depositing the work function material comprises one or more sequential cycles of:
introducing a metal halide precursor into a processing chamber to form a first layer or first monolayer on the substrate surface;
purging the metal halide precursor using a purge gas;
introducing a nitrogen free reactive gas into the processing chamber to form a second layer or second monolayer; and
purging the nitrogen free reactive gas using the purge gas.
6. The method of claim 5 , wherein the work function material is not a nitride.
7. The method of claim 5 , wherein M is tantalum, X is fluorine, and y is 5.
8. The method of claim 5 , wherein M is tantalum, X is chlorine, and y is 5.
9. The method of claim 5 , wherein the work function material is tantalum silicide.
10. The method of claim 9 , wherein the work function material has a ratio of tantalum to silicon of between 0.90 and 1.75, inclusive.
11. The method of claim 1 , wherein the work function material does not contain nitrogen.
12. The method of claim 1 , wherein M is tantalum, X is fluorine, and y is 5.
13. The method of claim 1 , wherein M is tantalum, X is chlorine, and y is 5.
14. The method of claim 1 , wherein the work function material is tantalum silicide.
15. The method of claim 1 , wherein depositing the work function material involves a pulsed chemical vapor deposition process wherein the substrate is sequentially exposed to the at least one metal halide precursor, a first purge gas, a second precursor, and a second purge gas.
16. The method of claim 15 , wherein the second precursor is not organometallic.
17. A method for processing a substrate, comprising:
depositing a dielectric material having a dielectric constant greater than 10;
forming a feature definition in the dielectric material;
depositing a work function material conformally on the sidewalls and bottom of the feature definition; and
depositing a metal gate fill material on the work function material to fill the feature definition, wherein the work function material is deposited by reacting at least one metal- halide precursor having the formula MX y , wherein M is tantalum, hafnium, titanium, and lanthanum, X is selected from the group of fluorine, chlorine, bromine, or iodine, and y is from 3 to 5, wherein the metal gate fill material and the work function material are the same material, and
depositing the work function material includes introducing the at least one metal-halide precursor into a processing chamber, introducing a first purge gas into the processing chamber, then introducing a nitrogen free reactive gas into the processing chamber.