Integrating atomic scale processes: ALD (atomic layer deposition) and ale (atomic layer etch)

• US 10,186,426 B2
• Filed: 09/28/2017
• Issued: 01/22/2019
• Est. Priority Date: 01/12/2015
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Kanarik, Keren Jacobs, Marks, Jeffrey, Singh, Harmeet, Tan, Samantha, Kabansky, Alexander, Yang, Wenbing, Kim, Taeseung, Hausmann, Dennis M., Lill, Thorsten
• Primary Examiner(s): Sullivan, Caleen
• Application Number:
  US15/719,484
• Publication Number:
  US 20180033635A1
• Time in Patent Office: 481 Days
• Field of Search: 438704
• CPC Class Codes: C23C 16/402 Silicon dioxide
• CPC Class Codes: C23C 16/45527 characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations
• CPC Class Codes: C23C 16/45536 Use of plasma, radiation or electromagnetic fields
• CPC Class Codes: C23C 16/45544 characterized by the apparatus
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01J 2237/334 Etching
• CPC Class Codes: H01J 37/32009 Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources plasma generation in general H05H1/24
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• 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 21/30655 comprising alternated and repeated etching and passivation steps, e.g. Bosch process
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/32137 of silicon-containing layers
• CPC Class Codes: H01L 21/67069 for drying etching
• CPC Class Codes: H01L 21/67207 comprising a chamber adapted to a particular process
• CPC Class Codes: H01L 21/6831 using electrostatic chucks
• CPC Class Codes: H10N 50/01 Manufacture or treatment

Abstract

Methods are provided for integrating atomic layer etch and atomic layer deposition by performing both processes in the same chamber or reactor. Methods involve sequentially alternating between atomic layer etch and atomic layer deposition processes to prevent feature degradation during etch, improve selectivity, and encapsulate sensitive layers of a semiconductor substrate.

Claims

1. A method of processing a substrate, the method comprising:

etching a first material on the substrate by atomic layer etch in a chamber; and

depositing a second material onto the substrate by atomic layer deposition,

wherein the etching and the depositing are performed without breaking vacuum, and

wherein the first material comprises a semiconductor material.

2. The method of claim 1, wherein the first material is selected from the group consisting of silicon and germanium.

3. The method of claim 1, wherein the second material is selected from the group consisting of oxides, nitrides, silicon oxynitride, metals, and metal-containing films.

4. The method of claim 1, wherein the etching is performed in cycles, a cycle comprising

exposing the substrate to an etching gas to modify the first material on a surface of the substrate to form a modified first material;

and

exposing the substrate to a removal gas to remove at least some of the modified first material on the surface.

5. The method of claim 4, wherein the etching gas is a halide.

6. The method of claim 4, wherein the removal gas is selected from the group consisting of nitrogen, argon, helium, neon, and oxygen.

7. The method of claim 4, wherein the removal gas is an inert gas.

8. The method of claim 4, wherein a plasma is ignited during the exposing of the substrate to the etching gas to modify the surface of the substrate.

9. The method of claim 8, wherein the plasma is ignited in the chamber.

10. The method of claim 8, wherein the plasma is ignited remotely.

11. The method of claim 4, the surface of the first material on the substrate is modified by a thermal reaction between the etching gas and the first material on the substrate.

12. The method of claim 1, wherein the depositing is performed in cycles, a cycle comprising

exposing the substrate to a deposition precursor to modify a surface of the substrate;

and

exposing the substrate to a second reactant to deposit the second material.

13. The method of claim 12, wherein the deposition precursor is a metal-containing precursor.

14. The method of claim 12, wherein the depositing is performed using sub-saturated atomic layer deposition.

15. The method of claim 12, wherein the second reactant is selected from the group consisting of oxygen, nitrogen, and combinations thereof.

16. The method of claim 1, wherein the depositing is performed in the chamber.

17. The method of claim 1, wherein at least one of the etching or the depositing is a self-limiting reaction.

18. A method of processing a substrate, the method comprising:

providing a substrate having one or more features, each feature comprising sidewalls;

depositing a protective layer comprising a first material by atomic layer deposition; and

after depositing the protective layer on the sidewalls, etching a second material on the substrate by atomic layer etch to leave the first material on the sidewalls,

wherein the depositing and the etching are performed without breaking vacuum.

19. The method of claim 18, wherein each feature comprises a feature opening less than 150 nm in diameter.

20. The method of claim 18, wherein each feature has an aspect ratio of at least 5:

1.

21. The method of claim 18, wherein at least one of the etching or the depositing is a self-limiting reaction.