Atomic layer deposition of hafnium-based high-k dielectric
View Patent ↗A method of depositing a hafnium-based dielectric film is provided. The method comprises atomic layer deposition using ozone and one or more reactants comprising a hafnium precursor. A semiconductor device is also provided. The device comprises a substrate, a hafnium-based dielectric layer formed atop the substrate, and an interfacial layer formed between the substrate and the hafnium-based dielectric layer, wherein the interfacial layer comprises silicon dioxide and has a crystalline structure.
1. A method of depositing a hafnium-based dielectric film comprising the step of atomic layer deposition using ozone and one or more reactants comprising a hafnium precursor wherein the hafnium precursor comprises TDMAHf, TDEAHf, Hf(MMP) 4 , or TEMAHf.
2. The method of claim 1 wherein the atomic layer deposition is conducted under a temperature below 400° C.
3. The method of claim 1 wherein the one or more reactants and ozone are injected into an ALD chamber through a showerhead injector.
4. The method of claim 1 wherein the one or more reactants further comprise a silicon precursor and the hafnium-based dielectric film comprises a hafnium silicate layer atop a substrate and an interfacial silicon oxide layer between the hafnium silicate layer and the substrate.
5. The method of claim 4 wherein the silicon precursor and hafnium precursor are mixed and co-injected into an ALD chamber during the atomic layer deposition.
6. The method of claim 4 wherein the silicon precursor and hafnium precursors are alternatively and independently injected into an ALD chamber during the atomic layer deposition.
7. A semiconductor device comprising:
a substrate;
a hafnium-based dielectric layer formed atop the substrate; and
an interfacial layer formed between the substrate and the hafnium-based dielectric layer, wherein the interfacial layer comprises silicon dioxide and has a crystalline structure.
8. The semiconductor device of claim 7 wherein the hafnium-based dielectric is an amorphous.
9. The semiconductor device of claim 7 wherein the hafnium-based dielectric comprises hafnium dioxide.
10. The semiconductor device of claim 7 wherein the hafnium-based dielectric comprises hafnium silicates.
11. The semiconductor device of claim 7 wherein the thickness of the interfacial layer is in the range of about 2–5 angstroms.
12. The semiconductor device of claim 7 further comprising an electrode layer atop the hafnium-based dielectric layer.
13. The semiconductor device of claim 12 wherein the electrode layer is a gate electrode.