Water-free etching methods

• US 10,468,267 B2
• Filed: 10/24/2017
• Issued: 11/05/2019
• 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:
  US15/792,376
• Publication Number:
  US 20180350619A1
• Time in Patent Office: 742 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 plasma-free fluorine-containing precursor into a processing region of a semiconductor processing chamber while maintaining the processing region plasma free, wherein the processing region houses a substrate comprising a region of exposed oxide and an exposed region of metal-containing material;

while flowing the plasma-free 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 region of exposed oxide; and

removing at least a portion of the exposed oxide.

2. The etching method of claim 1, wherein the 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 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 plasma-free fluorine-containing precursor comprises anhydrous hydrogen fluoride.

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 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 hydrogen-containing precursor bypasses any remote plasma region containing plasma 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. A removal method comprising:

flowing a fluorine-containing precursor into a processing region of a semiconductor processing chamber, wherein the fluorine-containing precursor is plasma free, wherein the processing region houses a substrate comprising a high-aspect-ratio feature having an exposed region of oxide and an exposed region of metal-containing material, wherein the high-aspect-ratio feature is at least partially defined by an oxide material that is characterized by an aspect ratio of height to width greater than 1, and wherein the oxide material further defines the exposed region of oxide;

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 oxide and the exposed region of metal-containing material; and

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

14. The removal method of claim 13, wherein the etchant begins reacting with oxide without an incubation period.

15. The removal method of claim 13, wherein the hydrogen-containing precursor comprises an alcohol.

16. The removal method of claim 13, wherein the fluorine-containing precursor comprises hydrogen fluoride.

17. The removal method of claim 13, wherein the method is performed at a processing temperature of below or about 10°

C.

18. The removal method of claim 13, wherein the method is performed at a processing pressure of below or about 50 Torr.

19. The removal method of claim 13, wherein the metal is selected from the group consisting of cobalt, tungsten, and copper.