Semiconductor device and method for atomic layer deposition of a dielectric over a substrate

1. A method comprising:

performing an atomic layer deposition (ALD) process to deposit a dielectric material in a trench over a substrate, the trench having a width less than 10 nm and an aspect ratio larger than 20;

curing the dielectric material using an ultra violet (UV) light; and

annealing the dielectric material after the curing, wherein the annealing comprises a steam anneal process performed at a temperature below about 450° C. and for a time interval greater than about 30 minutes.

2. The method of claim 1 , wherein the ALD process and the curing the dielectric material are performed in situ.

3. The method of claim 1 , wherein the ALD process and the curing the dielectric material are performed in different chambers.

4. The method of claim 1 , wherein the curing the dielectric material is performed using an UV light with a wavelength between about 200 nm to about 400 nm.

5. The method of claim 1 , wherein the curing the dielectric material is performed for a time interval of between about 1 minute and about 4 minutes.

6. The method of claim 1 , wherein the curing the dielectric material is performed at a temperature of between about 10° C. to about 450° C.

7. The method of claim 1 , wherein the steam anneal process is performed at a temperature from about 350° C. to about 450° C.

8. The method of claim 1 , wherein the steam anneal process is performed for a time interval of between about 30 minutes to about 120 minutes.

9. A method comprising:

filling a recess over a substrate with an insulation material using an atomic layer deposition (ALD) process, the recess having a width less than 10 nm and an aspect ratio larger than 20; and

performing a post treatment to reduce an etching rate of the insulation material, wherein the performing the post treatment comprises:

curing the insulation material using an ultra violet (UV) light; and

performing a steam anneal process over a time interval greater than about 30 minutes at temperatures below about 450° C. to the insulation material after the curing.

10. The method of claim 9 , wherein the ALD process comprises a first deposition cycle comprising:

forming a first layer of the insulation material using a gas comprising SiH 3 N(C 3 H 7 ) 2 and O 3 ; and

performing a plasma treatment on the first layer using an O 2 plasma.

11. The method of claim 10 , wherein the ALD process further comprises a second deposition cycle after the first deposition cycle, wherein the second deposition cycle forms a second layer of the insulation material over the first layer of the insulation material.

12. The method of claim 10 , wherein a flow rate of SiH 3 N(C 3 H 7 ) 2 is between about 50 standard cubic centimeter per minute (sccm) to about 100 sccm, and a flow rate of O 3 is between about 4000 sccm to about 8000 sccm.

13. The method of claim 10 , wherein the first deposition cycle deposits about 0.4 angstroms to about 1 angstrom of the insulation material.

14. The method of claim 9 , wherein the ALD process is performed at least in part at a pressure between about 1.5 torr to about 2.2 torr.

15. The method of claim 9 , further comprising performing a physical vapor deposition (PVD) process or chemical vapor deposition (CVD) process to deposit a dielectric material over the insulation material after the performing the steam anneal.

16. A method of forming a Fin-Field Effect Transistor (FinFET) comprising:

forming a fin protruding above a substrate;

performing an atomic layer deposition (ALD) process to deposit an oxide film in a recess adjacent to the fin, wherein the recess has a width of less than 10 nm and an aspect ratio larger than 20, wherein the performing the ALD process comprises:

supplying a gas comprising a precursor and an oxidant to a deposition chamber having the substrate to form a first layer of the oxide film;

removing the gas from the deposition chamber; and

performing a plasma process to treat the first layer of the oxide film;

curing the oxide film using an ultra violet light; and

annealing the oxide film using a steam anneal process performed at a temperature between about 350° C. and about 450° C. over a time interval greater than about 30 minutes.

17. The method of claim 16 , wherein the plasma process is performed with an O 2 plasma with a flow rate between about 50 sccm and about 100 sccm.

18. The method of claim 16 , wherein the plasma process is performed with a pressure of 1.5 to about 2.2 torr.

19. The method of claim 16 , wherein the plasma process is performed at a temperature between about 350° C. and about 450° C.

20. The method of claim 16 , wherein the ALD process is performed for a process time of about 20 minutes to about 60 minutes.