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

• US 10,515,816 B2
• Filed: 12/14/2018
• Issued: 12/24/2019
• 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 SiamHwa, Kabansky, Alexander, Yang, Wenbing, Kim, Taeseung, Hausmann, Dennis M., Lill, Thorsten
• Primary Examiner(s): Sullivan, Caleen O
• Application Number:
  US16/220,583
• Publication Number:
  US 20190139778A1
• Time in Patent Office: 375 Days
• Field of Search: 438703, 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 comprising:

exposing a substrate housed in a chamber to alternating pulses of an etching gas and a removal gas to etch an amount of the substrate layer by layer, wherein the amount etched by exposing the substrate to the alternating pulses of the etching gas and removal gas is between about 1 Å and

about 50 Å

; and

exposing the substrate to alternating pulses of a first reactant and a second reactant to deposit a film to a thickness of between about 0.25 Å and

about 350 Å

over the substrate.

2. The method of claim 1, wherein the exposing the substrate to the alternating pulses of the etching gas and the removal gas and the exposing the substrate to the alternating pulses of the first reactant and the second reactant are performed to deposit material on the substrate.

3. The method of claim 1, wherein the exposing the substrate to the alternating pulses of the etching gas and the removal gas and the exposing the substrate to the alternating pulses of the first reactant and the second reactant are performed to etch material on the substrate.

4. The method of claim 1, wherein the exposing the substrate to the alternating pulses of the etching gas and the removal gas further comprises directionally sputtering the substrate.

5. The method of claim 1, wherein the exposing the substrate to the alternating pulses of the etching gas and the removal gas and the exposing the substrate to the alternating pulses of the first reactant and the second reactant is performed in the same chamber.

6. The method of claim 1, wherein at least one of the exposing the substrate to the alternating pulses of the etching gas and the removal gas or the exposing the substrate to the alternating pulses of the first reactant and the second reactant is a self-limiting reaction.

7. The method of claim 1, wherein (a) further comprises applying a bias to the substrate.

8. The method of claim 1, wherein the removal gas is a carrier gas selected from the group consisting of N₂, Ar, He, and Ne.

9. A method comprising:

providing a substrate having exposed areas and features, wherein the features have corners;

selectively depositing a first material on the corners of the features by atomic layer deposition; and

etching a second material from the exposed areas on the substrate by atomic layer etch,

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

10. The method of claim 9, wherein the atomic layer deposition 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 reducing agent to selectively deposit the first material.

11. The method of claim 10, further comprising igniting a plasma when exposing the substrate to the reducing agent.

12. The method of claim 9, wherein the atomic layer etch is performed in cycles, a cycle comprising

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

and

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

13. The method of claim 12, wherein the removal gas is a carrier gas selected from the group consisting of N2, Ar, He, and Ne.

14. The method of claim 12, further comprising igniting a plasma when exposing the substrate to the removal gas.

15. The method of claim 9, wherein the etching the second material further comprises applying a bias to the substrate.

16. The method of claim 9, wherein the etching the second material further comprises directionally sputtering the substrate.

17. The method of claim 9, wherein at least one of the atomic layer deposition or the atomic layer etch is a self-limiting reaction.

18. The method of claim 9, wherein the atomic layer etch and atomic layer deposition are performed in the same chamber and are performed sequentially.