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

• US 9,576,811 B2
• Filed: 04/24/2015
• Issued: 02/21/2017
• 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 O
• Application Number:
  US14/696,254
• Publication Number:
  US 20160203995A1
• Time in Patent Office: 669 Days
• Field of Search: 438/703
• US Class Current: 1/1
• 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 the substrate by atomic layer etch in a chamber; and

depositing a film by atomic layer deposition,

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

2. 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 surface of the substrate;

and

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

3. The method of claim 2, wherein exposing the substrate to the etching gas further comprises igniting a plasma.

4. The method of claim 3, wherein the chamber is purged between exposing the substrate to the etching gas and exposing the substrate to the removal gas.

5. The method of claim 2, further comprising applying a bias to the substrate.

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

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

and

exposing the substrate to a reducing agent to deposit the film.

7. The method of claim 6, further comprising igniting a plasma.

8. The method of claim 1, wherein the etching and the depositing are performed to deposit material on the substrate.

9. The method of claim 1, wherein the etching and the depositing are performed to etch material on the substrate.

10. The method of claim 1, wherein the etching further comprises directionally sputtering the substrate.

11. The method of claim 1, wherein the etching and the depositing is performed in the same chamber.

12. The method of claim 1, wherein the etching is performed nonconformally.

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

14. A method comprising:

(a) exposing a substrate housed in a chamber to alternating pulses of an etching gas and a removal gas to etch the substrate layer by layer, wherein a plasma is ignited during at least one of a pulse of the etching gas and a pulse of the removal gas; and

(b) exposing the substrate to alternating pulses of a first reactant and a second reactant to deposit a film over the substrate.

15. The method of claim 14, wherein the removal gas is a carrier gas selected from the group consisting of N₂, Ar, He, and Ne.

16. The method of claim 14, wherein (a) and (b) are performed in the same chamber and are performed sequentially.

17. The method of claim 14, wherein (a) further comprises applying a bias to the substrate.

18. The method of claim 14, wherein at least one of (a) or (b) is a self-limiting reaction.

19. The method of claim 14, wherein (a) and (b) are repeated to deposit material on the substrate.

20. The method of claim 14, wherein (a) and (b) are repeated to etch a film on the substrate.

21. The method of claim 14, wherein (a) and (b) are performed without breaking vacuum.

22. The method of claim 14, wherein (a) and (b) are performed in the same chamber.

23. The method of claim 14, wherein the plasma is ignited during the pulse of the removal gas.

24. The method of claim 14, wherein the chamber is purged between the alternating pulses of the etching gas and the removal gas.

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

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

depositing a film by atomic layer deposition,

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

wherein a plasma is ignited during at least one of the etching and the depositing.

26. The method of claim 25, wherein the etching is performed in cycles, a cycle comprising

exposing the substrate to an etching gas to modify the surface of the substrate, and

exposing the substrate to a removal gas to remove at least some of the modified surface;

wherein the plasma is ignited during the exposing the substrate to the removal gas; and

wherein the chamber is purged between exposing the substrate to the etching gas and exposing the substrate to the removal gas.