Sidewall Image Transfer Using the Lithographic Stack as the Mandrel

• US 20110111596A1
• Filed: 11/06/2009
• Published: 05/12/2011
• Est. Priority Date: 11/06/2009
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kanakasabapathy, Sivananda K.
• Granted Patent: US 8,455,364 B2
• Time in Patent Office: Days
• US Class Current: 438/694
• 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 21/0338 Process specially adapted to improve the resolution of the mask
• CPC Class Codes: H01L 21/3086 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 21/3088 Process specially adapted to improve the resolution of the mask
• CPC Class Codes: H01L 21/32139 using masks
• CPC Class Codes: H01L 29/66795 with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET

Abstract

In one non-limiting exemplary embodiment, a method includes: providing a structure having at least one lithographic layer on a substrate, where the at least one lithographic layer includes a planarization layer (PL); forming a sacrificial mandrel by patterning at least a portion of the at least one lithographic layer using a photolithographic process, where the sacrificial mandrel includes at least a portion of the PL; and producing at least one microstructure by using the sacrificial mandrel in a sidewall image transfer process.

Claims

1. A method comprising:

providing a structure comprising at least one lithographic layer on a substrate, where the at least one lithographic layer comprises a planarization layer (PL);

forming a sacrificial mandrel by patterning at least a portion of the at least one lithographic layer using a photolithographic process, where the sacrificial mandrel comprises at least a portion of the PL; and

producing at least one microstructure by using the sacrificial mandrel in a sidewall image transfer process.

2. The method of claim 1, where the least one lithographic layer comprises:

a first silicon-containing antireflective coating (SiARC1) overlying the substrate, the PL overlying the SiARC1 and a second silicon-containing antireflective coating (SiARC2) overlying the PL.

3. The method of claim 2, where forming the sacrificial mandrel comprises patterning the SiARC2 and the PL into a shape of the sacrificial mandrel and removing the SiARC2.

4. The method of claim 3, where removing the SiARC2 further comprises removing a total thickness of the SiARC2 and removing a portion of the SiARC1, where the removed portion of the SiARC1 has a thickness less than the total thickness of the SiARC1.

5. The method of claim 3, where a thickness of the SiARC1 is greater than a thickness of the SiARC2.

6. The method of claim 5, where the SiARC1 has a thickness of about 70 nanometers and the SiARC2 has a thickness of about 35 nanometers.

7. The method of claim 3, where the sidewall image transfer process comprises:

depositing a film of oxide material and etching the oxide material to remove an oxide layer from a top surface of the mandrel and from other horizontal surfaces, where the etching results in formation of at least one oxide spacer having a desired shape of the microstructure.

8. The method of claim 7, where producing the at least one microstructure further comprises:

after the etching, removing a remaining portion of the PL and performing another etching to remove exposed portions of the SiARC1.

9. The method of claim 8, where producing the at least one microstructure further comprises:

patterning the substrate to form the at least one microstructure by using the at least one oxide spacer and a portion of the SiARC1 beneath the at least one oxide spacer as a mask, where the at least one microstructure comprises a portion of the substrate.

10. The method of claim 1, where the PL comprises a second planarization layer (PL2), where the least one lithographic layer comprises:

a first planarization layer (PL1) overlying the substrate, a first silicon-containing antireflective coating (SiARC1) overlying the PL1, the PL2 overlying the SiARC1 and a second silicon-containing antireflective coating (SiARC2) overlying the PL2.

11. The method of claim 10, where forming the sacrificial mandrel comprises patterning the SiARC2 and the PL2 into a shape of the sacrificial mandrel.

12. The method of claim 11, where the sidewall image transfer process comprises:

depositing a film of oxide material and etching the oxide material to remove an oxide layer from a top surface of the mandrel and from other horizontal surfaces, where the etching results in formation of at least one oxide spacer having a desired shape of the microstructure, where the etching of the oxide material further results in removal of a total thickness of the SiARC2 and removal of a portion of the SiARC1, where the removed portion of the SiARC1 has a thickness less than the total thickness of the SiARC1.

13. The method of claim 12, where a thickness of the SiARC1 is greater than a thickness of the SiARC2.

14. The method of claim 12, where producing the at least one microstructure further comprises:

after the etching, removing a remaining portion of the PL2, performing another etching to remove exposed portions of the SiARC1, removing exposed portions of the PL1, and patterning the substrate to form the at least one microstructure by using the at least one oxide spacer, a portion of the SiARC1 beneath the at least one oxide spacer and a portion of the PL1 beneath the at least one oxide spacer as a mask, where the at least one microstructure comprises a portion of the substrate.

15. The method of claim 11, where forming the sacrificial mandrel further comprises removing the SiARC2 prior to producing the at least one microstructure by using the sacrificial mandrel in the sidewall image transfer process.

16. The method of claim 15, where removing the SiARC2 further comprises removing a total thickness of the SiARC2 and removing a portion of the SiARC1, where the removed portion of the SiARC1 has a thickness less than the total thickness of the SiARC1.

17. The method of claim 15, where the sidewall image transfer process comprises:

depositing a film of oxide material and etching the oxide material to remove an oxide layer from a top surface of the mandrel and from other horizontal surfaces, where the etching results in formation of at least one oxide spacer having a desired shape of the microstructure.

18. The method of claim 17, where producing the at least one microstructure further comprises:

after the etching, removing a remaining portion of the PL2, performing another etching to remove exposed portions of the SiARC1, removing exposed portions of the PL1, and patterning the substrate to form the at least one microstructure by using the at least one oxide spacer, a portion of the SiARC1 beneath the at least one oxide spacer and a portion of the PL1 beneath the at least one oxide spacer as a mask, where the at least one microstructure comprises a portion of the substrate.

19. The method of claim 1, where the at least one lithographic layer further comprises at least one layer of antireflective coating material.

20. The method of claim 1, where the substrate comprises:

at least one hardmask layer, at least one silicon layer and at least one buried oxide layer.