Method of retaining the integrity of a photoresist pattern

• US 6,183,940 B1
• Filed: 03/17/1998
• Issued: 02/06/2001
• Est. Priority Date: 03/17/1998
• Status: Expired due to Fees

• Current Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Original Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Inventors: Wang, Chen-Yu, Lin, Ching-Kai, Syau, Tseng You
• Primary Examiner(s): Huff, Mark F.
• Assistant Examiner(s): BARRECA, NICOLE M
• Application Number:
  US09/040,480
• Time in Patent Office: 1,057 Days
• Field of Search: 430/313, 430/325, 430/328, 438/710, 438/695, 216/45, 216/46, 216/49
• US Class Current: 430/328
• CPC Class Codes: C23F 1/02 Local etching
• CPC Class Codes: C23F 4/00 Processes for removing metallic material from surfaces, not provided for in group C23F1/00 or C23F3/00
• CPC Class Codes: G03F 7/40 Treatment after imagewise removal, e.g. baking
• CPC Class Codes: H01L 21/0274 Photolithographic processes
• CPC Class Codes: H01L 21/0276 using an anti-reflective coating anti-reflective coating for lithography in general G03F7/09
• CPC Class Codes: H01L 21/32139 using masks

Abstract

A method of retaining the integrity of a photoresist pattern is provided where the patterned photoresist is treated prior to etching the principle layer. The pre-etch treatment encompasses a plasma treatment. In some embodiments employing an anti-reflective coating (ARC) layer, an isolation/protective layer is used to isolate the ARC from the photoresist. In some embodiments, the pre-etch treatment, advantageously provides for patterning the isolation/protection layer.

Claims

1. A method for retaining the integrity of a photoresist pattern comprising:

patterning a photosensitive material to form photoresist portions overlying a semiconductor substrate, said substrate including at least one layer of material formed thereon; and

treating said photoresist portions with a plasma derived from a fluorocarbon to form etch resistant photoresist portions,

said treating of said etch resistant photoresist portions including simultaneously etching of at least one layer disposed on said semiconductor substrate.

2. The method of claim 1 wherein patterning said photosensitive material comprises patterning an I-line sensitive material or a DUV sensitive material.

3. The method of claim 2 wherein forming photoresist portions overlying a semiconductor substrate comprises forming photoresist portions overlying a metal layer.

4. The method of claim 3 wherein forming photoresist portions overlying a metal layer comprises forming photoresist portions overlying an anti-reflective coating layer disposed on said metal layer.

5. The method of claim 4 wherein patterning said photoresist material comprises patterning an I-line photoresist material.

6. The method of claim 4 wherein forming said anti-reflective coating layer on said metal layer comprises forming an isolation/capping layer disposed on said anti-reflective coating layer.

7. The method of claim 6 wherein patterning said photoresist material comprises patterning a DUV photoresist material.

8. The method of claim 4 wherein treating said photoresist portions with a plasma derived from a fluorocarbon comprises creating a plasma derived from a fluorocarbon comprising CHF₃ or a mixture of CHF₃ and CF₄.

9. The method of claim 4 wherein treating said photoresist portions with a plasma derived from a fluorocarbon comprises creating a plasma derived from a gas mixture comprising CHF₃, N₂ and Ar.

10. The method of claim 9 wherein said etching of at least one layer, comprises etching of an isolation/capping layer disposed on said anti-reflective coating layer.

11. The method of claim 9 wherein creating a plasma derived from a gas mixture comprising CHF₃, N₂ and Ar comprises creating said plasma at a pressure between approximately 100 to 300 milliTorr with approximately 100 to 600 watts of electrical energy.

12. The method of claim 11 wherein treating said photoresist portions with a plasma comprises maintaining said plasma for between approximately 5 to 20 seconds.

13. The method of claim 11 wherein creating a plasma derived from a gas mixture comprising CHF₃, N₂ and Ar comprises creating said plasma at a pressure of approximately 150 milliTorr with approximately 500 watts of electrical energy.

14. The method of claim 13 wherein treating said photoresist portions with a plasma comprises maintaining said plasma for approximately 15 seconds.

15. A method for patterning a metal layer overlying a semiconductor substrate comprising:

forming a patterned layer of photosensitive material overlying a metal layer disposed on said substrate;

treating said patterned layer of photosensitive material with a plasma derived from a gas mixture comprising CHF₃, said treating of said patterned layer of photosensitive material including simultaneously etching of an isolation/capping layer disposed on said metal layer to expose portions of said metal layer; and

etching said metal layer to remove said exposed portions of said metal layer.

16. The method of claim 15 wherein forming a patterned layer of photosensitive material comprises forming said patterned layer of an I-line sensitive material or a DUV sensitive material.

17. The method of claim 15 wherein treating said patterned layer of photosensitive material with a plasma derived from a gas mixture comprising CHF₃ comprises igniting said plasma at a pressure between about 100 to 300 milliTorr.

18. The method of claim 15 wherein treating said patterned layer of photosensitive material with a plasma derived from a gas mixture comprising CHF₃ comprises using between about 100 to 600 watts of electrical energy to ignite said plasma.

19. A method for retaining the integrity of a photoresist pattern comprising:

forming a pattern of photosensitive resist over a metal layer disposed on a substrate wherein portions of said metal layer are exposed;

treating said pattern of photosensitive resist with a plasma derived from a fluorocarbon to form etch resistant resist; and

etching an isolation/protection layer disposed on said exposed portions of said metal layer, simultaneously with said treating said pattern of photosensitive resist with said plasma.