Removal methods for high aspect ratio structures

Patent metadata

Field	Value
Publication number	US-9768034-B1
Application number	US-201615349530-A
Country	US
Kind code	B1
Filing date	Nov 11, 2016
Priority date	Nov 11, 2016
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

Exemplary cleaning or etching methods may include flowing a fluorine-containing precursor into a remote plasma region of a semiconductor processing chamber. Methods may include forming a plasma within the remote plasma region to generate plasma effluents of the fluorine-containing precursor. The methods may also include flowing the plasma effluents into a processing region of the semiconductor processing chamber. A substrate may be positioned within the processing region, and the substrate may include a region of exposed oxide. Methods may also include providing a hydrogen-containing precursor to the processing region. The methods may further include removing at least a portion of the exposed oxide while maintaining a relative humidity within the processing region below about 50%. Subsequent to the removal, the methods may include increasing the relative humidity within the processing region to greater than or about 50%. The methods may further include removing an additional amount of the exposed oxide.

First claim

The invention claimed is:

1. An etching method comprising:
flowing a fluorine-containing precursor into a remote plasma region of a semiconductor processing chamber;
forming a plasma within the remote plasma region to generate plasma effluents of the fluorine-containing precursor;
flowing the plasma effluents into a processing region of the semiconductor processing chamber, wherein the processing region houses a substrate comprising a region of exposed oxide;
providing a hydrogen-containing precursor to the processing region;
removing at least a portion of the exposed oxide while maintaining a relative humidity within the processing region below about 50%;
subsequent the removing at least a portion of the exposed oxide, increasing the relative humidity within the processing region to greater than or about 50%; and
removing an additional amount of the exposed oxide.

2. The etching method of claim 1 , further comprising continuing to flow the plasma effluents into the processing region while increasing the relative humidity within the processing region.

3. The etching method of claim 2 , wherein a flow rate of the plasma effluents is reduced while increasing the relative humidity within the processing region.

4. The etching method of claim 1 , further comprising reducing a temperature of the substrate while increasing the relative humidity within the processing region.

5. The etching method of claim 4 , wherein the temperature is reduced by at least about 5° C.

6. The etching method of claim 1 , further comprising increasing a pressure within the processing chamber while increasing the relative humidity within the processing region.

7. The etching method of claim 6 , wherein the pressure is increased by at least about 1 Torr.

8. The etching method of claim 1 , wherein the relative humidity is increased above about 65%.

9. The etching method of claim 1 , wherein after the additional amount of exposed oxide is removed, a concentration of fluorine in the substrate is below or about 5%.

10. The etching method of claim 1 , wherein after the additional amount of exposed oxide is removed, a concentration of oxygen in the substrate is below or about 8%.

11. The etching method of claim 1 , wherein the hydrogen-containing precursor bypasses the remote plasma region when provided to the processing region.

12. The etching method of claim 1 , wherein the processing region is maintained plasma free during the removing operations.

13. The etching method of claim 1 , wherein the relative humidity is increased incrementally by less than or about 20% per increment.

14. A cleaning method comprising:
flowing a fluorine-containing precursor into a remote plasma region of a semiconductor processing chamber while forming a plasma within the remote plasma region to generate plasma effluents of the fluorine-containing precursor;
flowing the plasma effluents into a processing region of the semiconductor processing chamber, wherein the processing region houses a substrate comprising a high-aspect-ratio feature having a region of exposed oxide;
while flowing the plasma effluents into the processing region, providing a hydrogen-containing precursor to the processing region;
removing at least a portion of the exposed oxide while maintaining a relative humidity within the processing region at greater than or about 50%;
subsequent the removing at least a portion of the exposed oxide, increasing a flow rate of the fluorine-containing precursor while maintaining the relative humidity within the processing region at greater than or about 50%; and
removing an additional amount of the exposed oxide.

15. The cleaning method of claim 14 , wherein removing an additional amount of the exposed oxide lowers a concentration of oxygen by at least about 5%.

16. The cleaning method of claim 14 , wherein the flow rate of the fluorine-containing precursor is increased by at least about 2 sccm.

17. The cleaning method of claim 14 , wherein a thickness of the exposed region of oxide prior to the removal operations is less than or about 2 nm.

18. The cleaning method of claim 14 , wherein a critical dimension of the high-aspect-ratio feature is reduced by less than or about 1%.

19. A removal method comprising:
flowing a fluorine-containing precursor into a remote plasma region of a semiconductor processing chamber while forming a plasma within the remote plasma region to generate plasma effluents of the fluorine-containing precursor;
flowing the plasma effluents into a processing region of the semiconductor processing chamber, wherein the processing region houses a substrate comprising a high-aspect-ratio feature having a region of exposed oxide;
while flowing the plasma effluents into the processing region, providing a hydrogen-containing precursor to the processing region;
continuing to flow the plasma effluents and the hydrogen-containing precursor into the processing region for at least about 200 seconds; and
removing at least a portion of the exposed oxide while maintaining a relative humidity within the processing region at greater than or about 50%.

20. The removal method of claim 19 , wherein the removing operation reduces a concentration of oxygen within the substrate by at least about 3%.

Assignees

• Applied Materials Inc

Inventors

• Xu Lin
• Chen Zhijun
• Huang Jiayin
• Wang Anchuan

Classifications

• H10P72/0421

  for drying etching · CPC title

• H10P70/20 Primary

  Cleaning during device manufacture · CPC title

• H10P50/283

  by chemical means · CPC title

• H10P50/242

  of Group IV materials · CPC title

• H10P50/267 Primary

  using plasmas · CPC title