Temporally pulsed and kinetically modulated CVD dielectrics for gapfill applications

1. A method for performing temporally pulsed chemical vapor deposition (CVD) on a substrate, comprising:

providing a first reactant to a process chamber in which the substrate is disposed, the first reactant being configured to adsorb on exposed surfaces of the substrate in a self-limiting manner, the first reactant being provided at a partial pressure so that the first reactant diffuses into a gap feature of the substrate;

performing a first purge operation, the first purge operation being configured to partially purge gas phase first reactant species, that were not adsorbed, from the process chamber, wherein the first purge operation does not completely remove the gas phase first reactant species from the gap feature, so that a portion of the gas phase first reactant species remains in the gap feature;

providing a second reactant to the process chamber, the second reactant being configured to react with the first reactant to form a film product, including reaction of the provided second reactant with the adsorbed first reactant species, and reaction of the provided second reactant with the gas phase first reactant species in the gap feature;

performing a second purge operation, the second purge operation being configured to partially purge unreacted second reactant species, that did not react with the first reactant, from the process chamber, wherein the second purge operation does not completely remove the unreacted second reactant species from the gap feature, so that a portion of the unreacted second reactant species remains in the gap feature.

2. The method of claim 1 , wherein the gas phase first reactant species remaining in the gap feature following the first purge operation are distributed along a concentration gradient such that the concentration of the gas phase first reactant species increases with increasing depth in the gap feature.

3. The method of claim 1 , wherein the method provides for increased deposition rate of the film product with increased depth in the gap feature.

4. The method of claim 1 , wherein the reaction of the provided second reactant with adsorbed first reactant species forms the film product on the surfaces on which the first reactant has adsorbed, and wherein the reaction of the provided second reactant with the gas phase first reactant species in the gap feature forms the film product in the gas phase, the film product formed in the gas phase being subsequently deposited on a surface of the gap feature.

5. The method of claim 1 , wherein the second reactant is provided at a partial pressure that is less than the partial pressure of the first reactant.

6. The method of claim 5 , wherein a temperature of the process chamber is controlled to provide for the partial pressures of the first reactant and the second reactant.

7. The method of claim 1 , further comprising:

repeating the operations of the method for a predefined number of cycles so as to deposit multiple layers of the film product, wherein a deposition amount of the film product in the gap feature increases with increasing depth in the gap feature.

8. The method of claim 1 ,

wherein exposing the substrate to the first reactant includes pulsing the first reactant into a carrier gas stream that is flowed into the process chamber in which the substrate is disposed;

wherein exposing the substrate to the second reactant includes, pulsing the second reactant into the carrier gas stream.

9. The method of claim 8 ,

wherein performing the first purge operation includes continuing the flow of the carrier gas stream through the process chamber and evacuating the process chamber;

wherein performing the second purge operation includes continuing the flow of the carrier gas stream through the process chamber and evacuating the process chamber.

10. The method of claim 1 ,

wherein the film product is an oxide of silicon; and

wherein the first reactant is a silicon-containing precursor.

11. The method of claim 10 , wherein the first reactant is diisopropylaminosilane (DIPAS), bis(diethylamine)silane (BDEAS) or bis(tertiarybuthylamine)silane (BTBAS).

12. The method of claim 11 , wherein the second reactant is oxygen.

13. The method of claim 12 ,

wherein the first reactant is provided at a partial pressure in the range of approximately 0.1 to 10 Torr;

wherein the second reactant is provided at a partial pressure in the range of approximately 0.1 to 10 Torr.

14. The method of claim 13 , wherein a duration of the first purge operation is in the range of approximately 0.001 to 0.10 seconds;

wherein a duration of the second purge operation is in the range of approximately 0.001 to 0.10 seconds.

15. A method for performing temporally pulsed chemical vapor deposition (CVD) on a substrate, comprising:

providing a first reactant to a process chamber in which the substrate is disposed, the first reactant being configured to adsorb on exposed surfaces of the substrate in a self-limiting manner, the first reactant being provided at a partial pressure so that the first reactant diffuses into a gap feature of the substrate, wherein the first reactant is diisopropylaminosilane (DIPAS), bis(diethylamine)silane (BDEAS) or bis(tertiarybuthylamine)silane (BTBAS);

performing a first purge operation, the first purge operation being configured to partially purge gas phase first reactant species, that were not adsorbed, from the process chamber, wherein the first purge operation does not completely remove the gas phase first reactant species from the gap feature, so that a portion of the gas phase first reactant species remains in the gap feature, wherein the gas phase first reactant species remaining in the gap feature following the first purge operation are distributed along a concentration gradient such that the concentration of the gas phase first reactant species increases with increasing depth in the gap feature;

providing a second reactant to the process chamber, the second reactant being configured to react with the first reactant to form a film product, including reaction of the provided second reactant with the adsorbed first reactant species, and reaction of the provided second reactant with the gas phase first reactant species in the gap feature, wherein the second reactant is oxygen;

performing a second purge operation, the second purge operation being configured to partially purge unreacted second reactant species, that did not react with the first reactant, from the process chamber, wherein the second purge operation does not completely remove the unreacted second reactant species from the gap feature, so that a portion of the unreacted second reactant species remains in the gap feature.

16. The method of claim 15 ,

wherein the first reactant is provided at a partial pressure in the range of approximately 0.1 to 10 Torr;

wherein the second reactant is provided at a partial pressure in the range of approximately 0.1 to 10 Torr;

wherein a duration of the first purge operation is in the range of approximately 0.01 to 0.10 seconds;

wherein a duration of the second purge operation is in the range of approximately 0.01 to 0.10 seconds.

17. The method of claim 15 , wherein the method provides for increased deposition rate of the film product with increased depth in the gap feature.

18. The method of claim 15 , wherein the reaction of the provided second reactant with adsorbed first reactant species forms the film product on the surfaces on which the first reactant has adsorbed, and wherein the reaction of the provided second reactant with the gas phase first reactant species in the gap feature forms the film product in the gas phase, the film product formed in the gas phase being subsequently deposited on a surface of the gap feature.

19. The method of claim 15 , further comprising:

repeating the operations of the method for a predefined number of cycles so as to deposit multiple layers of the film product, wherein a deposition amount of the film product in the gap feature increases with increasing depth in the gap feature.

20. The method of claim 15 ,

wherein exposing the substrate to the first reactant includes pulsing the first reactant and the additive into a carrier gas stream that is flowed into the process chamber in which the substrate is disposed;

wherein exposing the substrate to the second reactant includes, pulsing the second reactant into the carrier gas stream;

wherein performing the first purge operation includes continuing the flow of the carrier gas stream through the process chamber and evacuating the process chamber;

wherein performing the second purge operation includes continuing the flow of the carrier gas stream through the process chamber and evacuating the process chamber.