Water-free etching methods

• US 10,497,579 B2
• Filed: 05/31/2017
• Issued: 12/03/2019
• Est. Priority Date: 05/31/2017
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Chen, Zhijun, Xu, Lin, Wang, Anchuan, Ingle, Nitin
• Primary Examiner(s): Duclair, Stephanie P
• Application Number:
  US15/609,483
• Publication Number:
  US 20180350617A1
• Time in Patent Office: 916 Days
• Field of Search: None
• CPC Class Codes: H01J 37/00 Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof H01J33/00, H01J40/00, H01J41/00, H01J47/00, H01J49/00 take precedence
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01L 21/306 Chemical or electrical treatment, e.g. electrolytic etching to form insulating layers H01L21/31
• CPC Class Codes: H01L 21/30621 Vapour phase etching
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/308 using masks H01L21/3063, H01L21/3065 take precedence
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/32135 by vapour etching only
• CPC Class Codes: H01L 21/32136 using plasmas
• CPC Class Codes: H01L 21/67167 surrounding a central transfer chamber

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 and a region of exposed metal. 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.

Claims

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 an exposed region of silicon oxide and an exposed region of metal;

providing a non-radical hydrogen-containing precursor to the processing region;

condensing the non-radical hydrogen-containing precursor to form a liquid of the non-radical hydrogen-containing precursor;

contacting the exposed region of silicon oxide with the liquid of the non-radical hydrogen-containing precursor; and

selectively removing at least a portion of the exposed silicon oxide relative to the exposed metal.

2. The etching method of claim 1, wherein the non-radical hydrogen-containing precursor comprises an alcohol.

3. The etching method of claim 2, wherein the alcohol is selected from the group consisting of methanol, ethanol, propanol, butanol, and pentanol.

4. The etching method of claim 1, further comprising increasing a pressure within the processing chamber while removing at least a portion of the exposed silicon oxide.

5. The etching method of claim 4, wherein the pressure is increased by at least about 1 Torr.

6. The etching method of claim 1, wherein the fluorine-containing precursor comprises nitrogen trifluoride.

7. The etching method of claim 1, further comprising reducing a temperature within the processing chamber while removing at least a portion of the exposed silicon oxide.

8. The etching method of claim 7, wherein the temperature is reduced by at least about 5°

C.

9. The etching method of claim 1, wherein the metal is selected from the group consisting of tungsten, cobalt, copper, titanium nitride, tantalum nitride, and cobalt silicide.

10. The etching method of claim 1, wherein the method is performed without providing water to the processing chamber.

11. The etching method of claim 1, wherein the non-radical 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 removing operation initiates without incubation when the liquid of the non-radical hydrogen-containing precursor contacts the exposed region of silicon oxide.

14. A removal method comprising:

flowing a fluorine-containing precursor into a processing region of a semiconductor processing chamber, wherein the processing region houses a substrate comprising a high-aspect-ratio feature having an exposed region of silicon oxide and an exposed region of metal-containing material;

while flowing the fluorine-containing precursor into the processing region, providing a hydrogen-containing precursor to the processing region to produce an etchant;

condensing the hydrogen-containing precursor on the exposed region of silicon oxide and the exposed region of metal-containing material; and

selectively removing at least a portion of the exposed silicon oxide with the etchant relative to the exposed metal-containing material, wherein the processing region is maintained plasma free during the removing operations.

15. The removal method of claim 14, wherein the etchant begins reacting with silicon oxide without an incubation period.

16. The removal method of claim 14, wherein the hydrogen-containing precursor comprises an alcohol.

17. The removal method of claim 14, wherein the fluorine-containing precursor comprises hydrogen fluoride.

18. The removal method of claim 14, wherein the method is performed at a processing temperature of below or about 10°

C.

19. The removal method of claim 14, wherein the method is performed at a processing pressure of below or about 50 Torr.

20. The removal method of claim 14, wherein the metal is selected from the group consisting of cobalt, tungsten, and copper.