METHODS OF POLYMERS DEPOSITION FOR FORMING REDUCED CRITICAL DIMENSIONS

• US 20130122707A1
• Filed: 10/19/2012
• Published: 05/16/2013
• Est. Priority Date: 11/14/2011
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Kim, Jong Mun, Shimizu, Daisuke
• Application Number:
  US13/656,589
• Publication Number:
  US 20130122707A1
• Time in Patent Office: Days
• US Class Current: 438/694
• CPC Class Codes: B05D 1/62 Plasma-deposition of organic layers plasma deposition in general C23C14/00, C23C16/00
• CPC Class Codes: B05D 5/00 Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
• CPC Class Codes: H01L 21/02118 carbon based polymeric organic or inorganic material, e.g. polyimides, poly cyclobutene or PVC polymers per se C08G, photoresist per se G03F
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0273 characterised by the treatment of photoresist layers
• CPC Class Codes: H01L 21/0332 characterised by their composition, e.g. multilayer masks, materials
• 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

Abstract

Methods of polymer deposition for forming reduced critical dimensions are described. In one embodiment, a substrate is provided into a chamber, the substrate having a patterned layer disposed on an underlying layer formed thereon. The patterned layer includes a plurality of openings, each opening having a sidewall, a bottom, and a critical dimension. A gas mixture is provided into the chamber, the gas mixture having an etching gas and a polymer control gas. The polymer control gas includes a polymerizing fluorocarbon C_xF_y gas and a C—H bond containing gas. A plasma is formed with the gas mixture and a conformal polymer layer is deposited in the presence of the plasma on the patterned layer to form a reduced critical dimension in each opening. The reduced critical dimension is smaller than the corresponding critical dimension of the opening.

Claims

1. A method comprising:

providing a substrate into a chamber, said substrate having a patterned layer disposed on an underlying layer formed thereon, wherein the patterned layer includes a plurality of openings, each opening having a sidewall, a bottom, and a critical dimension;

providing a gas mixture into the chamber, said gas mixture having an etching gas and a polymer control gas, wherein the polymer control gas includes a polymerizing fluorocarbon C_xF_y gas and a C—

H bond containing gas;

forming a plasma with the gas mixture; and

,

depositing in the presence of the plasma, a conformal polymer layer on the patterned layer to form a reduced critical dimension in each opening, wherein the reduced critical dimension is smaller than the corresponding critical dimension of the opening.

2. The method of claim 1, wherein the polymerizing fluorocarbon gas is provided at a ratio of between about 1:

1 and 4;

1 to the C—

H bond containing gas.

3. The method of claim 2, wherein the ratio of the polymerizing fluorocarbon gas to the C—

H bond containing gas is about 2;

1.

4. The method of claim 2, wherein the polymerizing fluorocarbon gas has a general formula C_xF_y where x=2-6 and y=2-8.

5. The method of claim 4, wherein the C—

H bond containing gas has a general formula C_xH_yF_z where x=1-6, y=1-8, z=0-6.

6. The method of claim 2, wherein the polymerizing fluorocarbon gas is C₄F₆ and/or C₄F₈.

7. The method of claim 2, wherein the C—

H bond containing gas is CH₂F₂.

8. The method of claim 2, wherein the C—

H bond containing gas is CH₂F₂ and the polymerizing fluorocarbon gas is C₄F₆ and/or C₄F₈.

9. The method of claim 1, wherein the etching gas is CF₄,

10. The method of claim 1, wherein the ratio of etching gas flow to polymer control gas flow is at least 8:

1.

11. The method of claim 1, further comprising providing a RF bias power source between about 300 W and 700 W normalized to a 300 mm substrate.

12. The method of claim 1, further comprising providing a RF bias power source having a frequency of between about 45 MHz and 75 MHz.

13. The method of claim 1, further comprising generating a chamber pressure between about 80 mT and 120 mT.

14. The method of claim 1, wherein the substrate is retained on a chuck in the chamber and the chuck is regulated at a temperature between about 0°

C. and 60°

C.

15. The method of claim 1, further comprising partially etching, prior to providing the gas mixture into the chamber, the underlying layer through the plurality of openings to form a plurality of partially etched features having the critical dimensions of the corresponding openings.

16. The method of claim 1, wherein the reduced critical dimensions are at least 45 nm smaller than the corresponding critical dimensions of the openings.

17. The method of claim 16, wherein the 3-sigma uniformity of the reduced CDs that correspond to the openings having approximately the same CDs is 1.7 nanometers or less across the substrate.

18. The method of claim 1, wherein the sidewall of an opening in the patterned layer has a tapered profile and the polymer layer produces a straight sidewall profile in the openings.

19. The method of claim 1, wherein the polymer layer increases the etch selectivity of the patterned layer.

20. The method of claim 1, wherein the patterned layer includes an opening having significant edge roughness and the polymer layer produces features in the openings having improved edge roughness.

21. The method of claim 1, wherein a sufficiently high chamber pressure is generated and a sufficiently low RF bias power is provided to form a plasma that predominately deposits polymer on the patterned layer and does not cause etch damage to the patterned layer and to the bottoms of the openings.

22. A method comprising:

providing a substrate into a chamber, said substrate having a patterned layer disposed on an underlying layer formed thereon, wherein the patterned layer includes a plurality of openings, each opening having a sidewall, a bottom, and a critical dimension;

providing a gas mixture into the chamber, said gas mixture having an etching gas and a polymer control gas, wherein the polymer control gas includes a polymerizing fluorocarbon C_xF_y gas and a C—

H bond containing gas, and wherein the polymerizing fluorocarbon gas is provided at a ratio of between about 1;

1 and 4;

1 to the C—

H bond containing gas;

providing into the chamber a RF bias power source at a frequency of approximately 60 MHz;

forming a plasma with the gas mixture; and

,

depositing in the presence of the plasma, a conformal polymer layer on the patterned layer to form a reduced critical dimension in each opening, wherein the reduced critical dimension is smaller than the corresponding critical dimension of the opening.

23. The method of claim 22, wherein the polymerizing fluorocarbon gas is C₄F₆ and/or C₄F₈.

24. The method of claim 22, wherein the C—

H bond containing gas is CH₂F₂.

25. The method of claim 22, wherein the C—

H bond containing gas is CH₂F₂ and the polymerizing fluorocarbon gas is C₄F₆ and/or C₄F₈.

26. A method comprising:

providing a substrate into a chamber, said substrate having a patterned layer disposed on an underlying layer formed thereon, wherein the patterned layer includes a plurality of openings, each opening having a sidewall, a bottom, and a critical dimension;

providing a gas mixture into the chamber, said gas mixture having an etching gas and a polymer control gas, wherein the etching gas is CH₄ and the polymer control gas includes a polymerizing fluorocarbon gas and a C—

H bond containing gas, wherein the polymerizing fluorocarbon gas is C₄F₆ and/or C₄F₈ and the C—

H bond containing gas is CH₂F₂, and wherein the polymerizing fluorocarbon gas is provided at a ratio of 2;

1 to the CH₂F₂ gas;

generating a chamber pressure of about 100 mT during polymer deposition;

retaining the substrate on a chuck in the chamber, wherein the chuck is regulated at a temperature between about 0°

C. and 60°

C.;

providing into the chamber a RF bias power source between about 300 W and 700 W at a frequency of approximately 60 MHz normalized to a 300 mm substrate;

forming a plasma with the gas mixture; and

,

depositing in the presence of the plasma, a conformal polymer layer on the patterned layer to form a reduced critical dimension in each opening, wherein the reduced critical dimension is smaller than the corresponding critical dimension of the opening.