SMOOTH SIDEWALL STRUCTURES

• US 20200135545A1
• Filed: 10/26/2018
• Published: 04/30/2020
• Est. Priority Date: 10/26/2018
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: GlobalFoundries, Inc.
• Inventors: SRIVASTAVA, Ravi P., GU, Sipeng, SINGH, Sunil K., DOU, Xinyuan, SEHGAL, Akshey, SUN, Zhiguo
• Granted Patent: US 10,714,380 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 21/02203 the layer being porous
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/0337 characterised by the process involved to create the mask, e.g. lift-off masks, sidewalls, or to modify the mask, e.g. pre-treatment, post-treatment
• CPC Class Codes: H01L 21/76814 post-treatment or after-treatment, e.g. cleaning or removal of oxides on underlying conductors
• CPC Class Codes: H01L 21/76825 by exposing the layer to particle radiation, e.g. ion implantation, irradiation with UV light or electrons etc. plasma treatment H01L21/76826

Abstract

The present disclosure generally relates to semiconductor structures and, more particularly, to smooth sidewall structures and methods of manufacture. The method includes: forming a plurality of mandrel structures; forming a first spacer material on each of the plurality of mandrel structures; forming a second spacer material over the first spacer material; and removing the first spacer material and the plurality of mandrel structures to form a sidewall structure having a sidewall smoothness greater than the plurality of mandrel structures.

Claims

1. A method comprising:

forming a plurality of mandrel structures;

forming a first spacer material on each of the plurality of mandrel structures;

forming a second spacer material over the first spacer material; and

removing the first spacer material and the plurality of mandrel structures to form a sidewall structure having a sidewall smoothness greater than the plurality of mandrel structures.

2. The method of claim 1, wherein the plurality of mandrel structures are a first material different than the first spacer material and the second spacer material.

3. The method of claim 1, wherein the plurality of mandrel structures have a line edge roughness.

4. The method of claim 3, wherein the first spacer material is deposited to a thickness that completely covers the line edge roughness of the plurality of mandrel structures.

5. The method of claim 4, wherein the first spacer material is deposited to a thickness of about 2 nm to 3 nm.

6. The method of claim 1, wherein the plurality of mandrels structures have a line width roughness.

7. The method of claim 1, wherein the first spacer film is composed of a carbon film.

8. The method of claim 1, wherein the first spacer film is composed of topaz.

9. The method of claim 8, wherein the second spacer film comprises one of a metal material, a nitride material, or a dielectric material.

10. The method of claim 1, wherein the forming the first spacer material and the second spacer material comprises a deposition process followed by an anisotropic etching process to expose the plurality of mandrel structures.

11. A method comprising:

forming a plurality of mandrel structures having rough surfaces;

depositing an aluminum film on the mandrel structures;

etching the aluminum film to form spacer structures;

depositing a spacer film over the mandrel structures and the spacer structures;

etching the spacer film to form smooth sidewall structures; and

removing the mandrel structures and the aluminum film, leaving the spacer film as a patterned shape.

12. The method of claim 11, wherein the rough surfaces are a line edge roughness.

13. The method of claim 11, wherein the mandrel structures have a line width roughness.

14. The method of claim 11, wherein the aluminum film is deposited to have a thickness greater than 2 nm to 3 nm.

15. The method of claim 11, wherein the aluminum film is comprised a topaz material.

16. The method of claim 11, wherein the etching of the aluminum film to form spacer structures and the etching of the spacer film comprises an anisotropic etching process to expose the mandrel structures for subsequent removal.

17. A method comprising:

forming a mandrel from a plurality of stacked materials;

forming a carbon film on the mandrel;

anisotropically etching the carbon film to expose the mandrel;

depositing a spacer material on the carbon film and the exposed mandrel, the spacer material being different than the carbon film;

anisotropically etching the spacer material to expose the mandrel and the carbon film; and

removing both the mandrel and the carbon film, leaving the anisotropically etched spacer material which has a sidewall smoothness different than the mandrel.

18. The method of claim 17, wherein the carbon film has an etch selectivity with respect to the spacer material.

19. The method of claim 17, wherein the spacer material is comprised of a metal material.

20. The method of claim 17, wherein the anisotropically etched spacer material has a sidewall smoothness greater than a sidewall of the mandrel.