HARDMASK OPEN PROCESS WITH ENHANCED CD SPACE SHRINK AND REDUCTION

• US 20090191711A1
• Filed: 01/30/2008
• Published: 07/30/2009
• Est. Priority Date: 01/30/2008
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Mukai, Kevin Mikio, Iwamoto, Yasunobu, Fung, Nancy, Rui, Ying, Zhao, Xiaoye
• Application Number:
  US12/022,496
• Publication Number:
  US 20090191711A1
• Time in Patent Office: Days
• US Class Current: 438/695
• CPC Class Codes: G03F 7/091 characterised by antireflection means or light filtering or absorbing means, e.g. anti-halation, contrast enhancement
• CPC Class Codes: G03F 7/40 Treatment after imagewise removal, e.g. baking
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/3266 Magnetic control means
• 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 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31138 by dry-etching
• CPC Class Codes: H01L 21/31144 using masks
• CPC Class Codes: H01L 21/76802 by forming openings in dielectrics

Abstract

Methods for forming an ultra thin structure. The method includes a polymer deposition and etching process. In one embodiment, the methods may be utilized to form fabricate submicron structure having a critical dimension less than 30 nm and beyond. The method further includes a multiple etching processes. The processes may be varied to meet different process requirements. In one embodiment, the process gently etches the substrate while shrinking critical dimension of the structures formed within the substrate. The dimension of the structures may be shank by coating a photoresist like polymer to sidewalls of the formed structure, but substantially no polymer accumulation on the bottom surface of the formed structure on the substrate. The embodiments described herein also provide high selectivity in between each layers formed on the substrate during the fabricating process and preserving a good control of profile formed within the structure.

Claims

1. A method of forming a submicron structure on a substrate suitable for a dual damascene application, comprising:

(a) providing a substrate having a patterned photoresist layer disposed on a film stack in an etch chamber, wherein the film stack includes a BARC layer disposed on a hardmask layer;

(b) supplying a first gas mixture to deposit a polymer on the pattered photoresist layer to reduce a dimension of an opening in the patterned photoresist layer;

(c) supplying a second gas mixture to etch the BARC layer through the reduced dimension of the opening of patterned photoresist layer; and

(d) supplying a third gas mixture to etch the hardmask layer through the opening formed in the etched BARC layer.

2. The method of claim 1, further comprising:

exposing the underlying hardmask layer through the opening formed in the etched BARC layer etched through the reduced dimension opening of the patterned photoresist layer.

3. The method of claim 1, further comprising:

repeating (b) and (c) until the underlying hardmask layer is exposed.

4. The method of claim 1, wherein the film stack further includes a dielectric layer disposed between the hardmask layer and the substrate.

5. The method of claim 4, further comprising:

etching the dielectric layer through the opening in the etched hardmask layer.

6. The method of claim 4, further comprising:

repeating (b)-(d) until the underlying dielectric layer is exposed.

7. The method of claim 1, wherein (d) supplying the third gas mixture further comprises:

forming a polymer layer on the hardmask layer while etching the hardmask layer.

8. The method of claim 1, wherein the hardmask layer includes a silicon nitride layer disposed on a silicon oxide layer.

9. The method of claim 4, wherein the film stack further includes an etch stop layer disposed between the hardmask layer and the dielectric layer.

10. The method of claim 1, wherein the first gas mixture includes an etching gas and a polymer gas, wherein the ratio of the etching gas and the polymer gas supplied in the first gas mixture is controlled between about 5:

1 and about 1;

5.

11. The method of claim 1, wherein the second gas mixture further comprises at least one of CF₄, C₄F₆, C₂H₂F₂, CHF₃, CH₃F, CO, CO₂, O₂, NH₃, H₂, SO₂, CH₄, C₂H₄, C₃H₈ or C₃H₆.

12. The method of claim 1, wherein the third gas mixture is substantially the same as the first gas mixture.

13. The method of claim 1, wherein the supplying the third gas mixture further comprises:

applying dual frequency RF power into the processing chamber.

14. A method of forming a submicron structure on a substrate suitable for a dual damascene application, comprising:

(a) providing a substrate having a patterned photoresist layer disposed on a film stack in an etch chamber, wherein the film stack includes a BARC layer, a hardmask layer and a dielectric layer sequentially disposed on the substrate;

(b) supplying a first gas mixture to deposit a polymer on the pattered photoresist layer to reduce a dimension of an opening in the patterned photoresist layer;

(c) supplying a second gas mixture to etch the BARC layer through the reduced dimension opening in patterned photoresist layer; and

(d) supplying a third gas mixture to etch the hardmask layer through an opening formed in the etched BARC layer until the underlying dielectric layer is exposed.

15. The method of claim 14, wherein supplying the third gas mixture further comprises:

forming a polymer layer on the hardmask layer while etching the hardmask layer.

16. The method of claim 14, wherein the hardmask layer includes a silicon nitride layer disposed on a silicon oxide layer.

17. The method of claim 14, wherein the film stack further includes an etch stop layer disposed between the dielectric layer and the hardmask layer.

18. A method of forming a submicron structure on a substrate suitable for a dual damascene application, comprising:

(a) providing a substrate having a patterned photoresist layer disposed on a film stack in an etch chamber, wherein the film stack includes a BARC layer, a hardmask layer and a dielectric layer sequentially disposed on the substrate, wherein the hardmask layer includes a silicon nitride layer disposed on a silicon oxide layer;

(b) supplying a first gas mixture to deposit a polymer on the pattered photoresist layer to reduce a dimension of an opening in the patterned photoresist layer;

(c) supplying a second gas mixture to etch the BARC layer through the reduced dimension opening in patterned photoresist layer; and

(d) supplying a third gas mixture to etch the hardmask layer through an opening formed in the etched BARC layer until the underlying dielectric layer is exposed, wherein the third gas mixture etches the hardmask layer while forming a polymer layer on the hardmask layer.

19. The method of claim 18, wherein (b), (c) and (d) are performed in the etch chamber.

20. An etch chamber coupled to a controller, the controller interfaced with computer readable media, that when executed by the controller, cause a process to be performed in the etch chamber, the process comprising:

depositing a polymer on a patterned photoresist layer such that openings through the photoresist layer are reduced in dimension;

etching an opening in a BARC layer through the reduced dimension opening; and

etching a hardmask layer to expose a dielectric layer through the opening in the BARC layer.

21. An etch chamber coupled to a controller, the controller interfaced with computer readable media, that when executed by the controller, cause a process to be performed in the etch chamber, the process comprising:

supplying a gas mixture including a C₄F₆ gas and a CF₄ gas, wherein C₄F₆ gas deposits a polymer on a patterned photoresist layer such that openings through the photoresist layer are reduced in dimension, while CF₄ gas etches an opening in a BARC layer and a hardmask layer through the reduced dimension opening until an underlying dielectric layer is exposed.