Self-limiting selective etching systems and methods

Patent metadata

Field	Value
Publication number	US-10755941-B2
Application number	US-201816028671-A
Country	US
Kind code	B2
Filing date	Jul 6, 2018
Priority date	Jul 6, 2018
Publication date	Aug 25, 2020
Grant date	Aug 25, 2020

Abstract

Exemplary etching methods may include flowing a hydrogen-containing precursor into a substrate processing region of a semiconductor processing chamber. The methods may include flowing a fluorine-containing precursor into the substrate processing region. The methods may include contacting a substrate housed in the substrate processing region with the hydrogen-containing precursor and the fluorine-containing precursor. The substrate may define a trench, and a layer of an oxygen-containing material may be disposed within the trench and exposed on the substrate. The methods may include halting delivery of the hydrogen-containing precursor. The methods may also include removing the oxygen-containing material.

First claim

The invention claimed is:

1. An etching method comprising:
flowing a hydrogen-containing precursor into a substrate processing region of a semiconductor processing chamber;
flowing a fluorine-containing precursor into the substrate processing region;
contacting a substrate housed in the substrate processing region with the hydrogen-containing precursor and the fluorine-containing precursor, wherein the substrate defines a trench, wherein a layer of an oxygen-containing material is disposed within the trench and exposed on the substrate;
halting delivery of the hydrogen-containing precursor for a remainder of the etching method while continuing to flow the fluorine-containing precursor; and
removing the oxygen-containing material, during the continued flowing of the fluorine-containing precursor.

2. The etching method of claim 1 , wherein the hydrogen-containing precursor is maintained fluidly isolated from a plasma formable within the semiconductor processing chamber in a remote plasma region of the semiconductor processing chamber.

3. The etching method of claim 1 , wherein the hydrogen-containing precursor comprises water vapor.

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

5. The etching method of claim 1 , wherein the substrate further comprises an exposed region of hafnium oxide, zirconium oxide, or aluminum oxide.

6. The etching method of claim 1 , wherein the oxygen-containing material is selected from the group consisting of silicon dioxide, silicon oxycarbide, silicon oxynitride, and silicon oxycarbonitride.

7. The etching method of claim 1 , wherein the etching method is performed at a temperature below or about 0° C.

8. The etching method of claim 7 , wherein the etching method is performed at a temperature above a freezing point of water at operating chamber conditions.

9. The etching method of claim 1 , wherein the fluorine-containing precursor is flowed at a flow rate below or about 1 slm during the etching method.

10. The etching method of claim 9 , wherein the fluorine-containing precursor is pulsed during the etching method.

11. The etching method of claim 10 , wherein the fluorine-containing precursor is pulsed off for at least two seconds during each cycle of pulsing performed during the etching method.

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

13. A removal method comprising:
flowing water vapor into a substrate processing region at a temperature below or about 0° C.;
flowing a fluorine-containing precursor into the substrate processing region of a semiconductor processing chamber;
contacting a substrate housed in the substrate processing region with the water vapor and the fluorine-containing precursor, wherein the substrate defines a trench, wherein a layer of an oxygen-containing material is disposed within the trench and exposed on the substrate;
halting the flow of water vapor for a remainder of the removal method while maintaining the flow of the fluorine-containing precursor; and
removing the oxygen-containing material, during the maintained flow of the fluorine-containing precursor.

14. The removal method of claim 13 , wherein the water vapor is delivered into the substrate processing region at a temperature above or about −40° C.

15. The removal method of claim 13 , wherein the fluorine-containing precursor is flowed at a rate of less than or about 500 sccm during the removal method.

16. The removal method of claim 13 , wherein the fluorine-containing precursor is delivered in pulses, wherein the delivery is characterized by a first period of time during which the fluorine-containing precursor is flowed, and a second period of time during which the fluorine-containing precursor flow is halted.

17. The removal method of claim 16 , wherein the first period of time and the second period of time are both greater than or about 2 seconds.

18. The removal method of claim 13 , wherein the fluorine-containing precursor is anhydrous hydrogen fluoride, and wherein the substrate processing region is maintained plasma-free during the removal method.

19. An etching method comprising:
flowing a hydrogen-containing precursor into a substrate processing region of a semiconductor processing chamber while maintaining the substrate process region at a temperature between about −50° C. and about 0° C.;
flowing anhydrous hydrogen fluoride into the substrate processing region;
contacting a substrate housed in the substrate processing region with the hydrogen-containing precursor and the anhydrous hydrogen fluoride, wherein the substrate defines a trench, wherein a layer of an oxygen-containing material is disposed within the trench and exposed on the substrate;
halting the flow of the hydrogen-containing precursor for a remainder of the etching method while continuing to flow the anhydrous hydrogen fluoride; and
removing the oxygen-containing material, during the continued flowing of the anhydrous hydrogen fluoride.

Assignees

• Applied Materials Inc

Inventors

• Chen Zhijun
• Kao Chia-Ling
• Wang Anchuan
• Ingle Nitin

Classifications

• H10P72/0421

  for drying etching · CPC title

• H10P70/00

  Cleaning of wafers, substrates or parts of devices · CPC title

• H10P50/691

  for Group V materials or Group III-V materials · CPC title

• H10P50/642

  Chemical etching · CPC title

• H10P50/267

  using plasmas · CPC title