Selective deposition of silicon oxide

• US 10,629,429 B2
• Filed: 11/30/2018
• Issued: 04/21/2020
• Est. Priority Date: 02/14/2017
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Smith, David Charles, Hausmann, Dennis M.
• Primary Examiner(s): Ahmed, Selim U
• Assistant Examiner(s): Clinton, Evan G
• Application Number:
  US16/206,915
• Publication Number:
  US 20190115207A1
• Time in Patent Office: 508 Days
• CPC Class Codes: C23C 16/02 Pretreatment of the material to be coated C23C16/04 takes precedence
• CPC Class Codes: C23C 16/0272 Deposition of sub-layers, e.g. to promote the adhesion of the main coating
• CPC Class Codes: C23C 16/04 Coating on selected surface areas, e.g. using masks
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/402 Silicon dioxide
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02219 the compound comprising silicon and nitrogen
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/02315 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/32 using masks

Abstract

Methods and apparatuses for selectively depositing silicon oxide on a silicon oxide surface relative to a silicon nitride surface are described herein. Methods involve pre-treating a substrate surface using ammonia and/or nitrogen plasma and selectively depositing silicon oxide on a silicon oxide surface using alternating pulses of an aminosilane silicon precursor and an oxidizing agent in a thermal atomic layer deposition reaction without depositing silicon oxide on an exposed silicon nitride surface.

Claims

1. A method of depositing silicon oxide selectively on an exposed silicon oxide surface, the method comprising:

providing a substrate having the exposed silicon oxide surface and an exposed silicon nitride surface, the exposed silicon nitride surface comprising primary amine groups;

exposing the substrate to an aminosilane to selectively adsorb the aminosilane to the exposed silicon oxide surface relative to the exposed silicon nitride surface to form an adsorbed aminosilane on the exposed silicon oxide surface; and

performing a thermal atomic layer deposition reaction comprising exposing the substrate to an oxidizing agent, whereby the thermal atomic layer deposition reaction forms silicon oxide on the exposed silicon oxide surface relative to the exposed silicon nitride surface.

2. The method of claim 1, further comprising, prior to providing the substrate, depositing silicon nitride to form an untreated silicon nitride surface;

and exposing the untreated silicon nitride surface to ammonia and igniting a plasma for a duration between about 1 second and about 10 seconds to form the exposed silicon nitride surface comprising primary amine groups.

3. The method of claim 1, further comprising, prior to providing the substrate, depositing silicon nitride to form an untreated silicon nitride surface and exposing the untreated silicon nitride surface to a mixture of nitrogen and ammonia and igniting a plasma for a duration between about 1 second and about 10 seconds to form the exposed silicon nitride surface comprising primary amine groups.

4. The method of claim 3, wherein amount of ammonia in the mixture of nitrogen and ammonia is less than about 1% by volume.

5. The method of claim 1, further comprising forming the exposed silicon nitride surface comprising primary amine groups by chemical vapor deposition at a deposition temperature greater than about 500°

C.

6. The method of claim 1, wherein the thermal atomic layer deposition reaction is performed at a deposition temperature between about 25°

C. and about 400°

C.

7. The method of claim 1, wherein, during the thermal atomic layer deposition reaction, the substrate is housed in a chamber having a chamber pressure between about 10 mTorr and about 10 Torr during selective deposition of the silicon oxide.

8. The method of claim 1, wherein exposing the substrate to the aminosilane comprises flowing the aminosilane at a flow rate between about 1000 sccm and about 5000 sccm.

9. The method of claim 1, wherein exposing the substrate to the oxidizing agent comprises flowing the oxidizing agent at a flow rate between about 1000 sccm and about 5000 sccm.

10. The method of claim 1, wherein the aminosilane is selected from the group consisting of monoaminosilane, diaminosilane, triaminosilane, tetraaminosilane, and combinations thereof.

11. The method of claim 1, wherein the oxidizing agent is selected from the group consisting of ozone, water, peroxide, and combinations thereof.

12. The method of claim 2, wherein the plasma is ignited using a plasma power between about 150 W and about 6000 W.

13. The method of claim 3, wherein the plasma is ignited using a plasma power between about 150 W and about 6000 W.

14. The method of claim 3, wherein mixture of ammonia gas and nitrogen gas includes a flow rate ratio of ammonia gas flow rate to nitrogen gas flow rate between about 0.01 and about 0.1.

15. The method of claim 14, wherein the ammonia gas flow rate is between about 10 sccm and about 100 sccm.

16. The method of claim 1, wherein the silicon oxide is formed by reacting the oxidizing agent with the adsorbed aminosilane to form the silicon oxide.