Simplified pitch doubling process flow

• US 8,030,217 B2
• Filed: 04/30/2010
• Issued: 10/04/2011
• Est. Priority Date: 04/07/2006
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Alapati, Ramakanth, Zhou, Baosuo, Niroomand, Ardavan
• Primary Examiner(s): Smith; Matthew
• Assistant Examiner(s): Lee; Jae
• Application Number:
  US12/771,951
• Publication Number:
  US 20100216307A1
• Time in Patent Office: 522 Days
• Field of Search: 438689-757
• US Class Current: 438/725
• CPC Class Codes: H01L 21/0338 Process specially adapted to improve the resolution of the mask
• CPC Class Codes: H01L 21/3088 Process specially adapted to improve the resolution of the mask
• CPC Class Codes: H01L 27/04 the substrate being a semiconductor body
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A method for fabricating a semiconductor device comprises patterning a layer of photoresist material to form a plurality of mandrels. The method further comprises depositing an oxide material over the plurality of mandrels by an atomic layer deposition (ALD) process. The method further comprises anisotropically etching the oxide material from exposed horizontal surfaces. The method further comprises selectively etching photoresist material.

Claims

1. A method, comprising:

providing a plurality of photoresist mandrels over a substrate;

providing a blanket layer of spacer material on the plurality of mandrels;

providing a layer of photoresist material on the blanket layer of spacer material;

patterning the layer of photoresist material;

subsequently simultaneously patterning spacer material under the patterned layer of photoresist material and forming spacers on sidewalls of the mandrels by etching the blanket layer of spacer material, wherein the photoresist material is disposed over ends of the spacers during subsequently simultaneously patterning spacer material;

simultaneously selectively removing the mandrels and the patterned layer of photoresist material to leave a plurality of spacers over the substrate; and

transferring a pattern defined by the spacers and the patterned spacer to an underlying substrate.

2. The method of claim 1, wherein providing the blanket layer of spacer material comprises performing an atomic layer deposition.

3. The method of claim 2, wherein the atomic layer deposition is conducted at less than about 100°

C.

4. The method of claim 3, wherein the oxide is deposited using Si₂Cl₆, H₂O and C₅H₅N as precursors.

5. The method of claim 2, wherein performing the atomic layer deposition comprises depositing an oxide.

6. The method of claim 1, further comprising transferring the pattern defined by the spacers and the patterned spacer material to at least one underlying layer of material before transferring the pattern defined by the spacers and the patterned spacer material to the substrate.

7. The method of claim 6, wherein the at least one underlying layer of material is a hard mask layer.

8. The method of claim 7, wherein the hard mask layer comprises amorphous carbon.

9. The method of claim 1, wherein the mandrels have a width of less than about 150 nm.

10. The method of claim 1, wherein the oxide material is deposited at a temperature less than about 100°

C.

11. The method of claim 1, wherein the layer of photoresist material comprises a material selected from the group consisting of argon fluoride photoresist, and krypton fluoride photoresist.

12. A method, comprising:

providing a plurality of mandrels over a substrate;

providing a blanket layer of spacer material over the mandrels;

providing a masking layer on the blanket layer, the masking layer having a pattern and extending over the spacer material at ends of the mandrels;

etching the blanket layer to define spacers at sidewalls of the mandrels and to transfer the pattern from the masking layer to underlying portions of the blanket layer wherein the masking layer extends over the spacer material at the ends of the mandrels during etching the blanket layer;

removing the mandrels and the patterned masking layer to form a mask pattern defined by spacers and patterned portions of the blanket layer; and

transferring the mask pattern to underlying material.

13. The method of claim 12, wherein providing the plurality of mandrels comprises:

providing a photoresist layer; and

patterning the photoresist layer, wherein patterned photoresist forms the mandrels.

14. The method of claim 12, wherein providing the blanket layer of spacer material comprises depositing the layer of spacer material by atomic layer deposition.

15. The method of claim 12, wherein providing a masking layer comprises:

depositing a photoresist layer on the blanket layer of spacer material; and

patterning the photoresist layer.

16. The method of claim 12, wherein etching the blanket layer comprises performing an anisotropic etch.

17. The method of claim 12, wherein the mandrels and the patterned masking layer are formed of a same material, wherein removing the mandrels and the patterned masking layer comprises exposing the mandrels and the patterned masking layer to a same etch process.

18. The method of claim 12, wherein transferring the masking pattern to underlying material comprises transferring the masking pattern to a hard mask layer and subsequently transferring the masking pattern to an underlying substrate.

19. A method, comprising:

providing mandrels over the substrate, the mandrels disposed in an array region and outside of a periphery region of the substrate;

providing a spacer layer on the mandrels and extending over the array and the periphery regions;

depositing a layer of photoresist on the spacer layer;

patterning the layer of photoresist to form a photoresist pattern, wherein photoresist extends over the spacer layer at ends of the mandrels; and

subsequently forming spacers at sidewalls of the mandrels and transferring the photoresist pattern into the spacer layer to form a patterned spaced layer, wherein the photoresist pattern extends over the spacer layer at the ends of the mandrels during subsequently forming spacers.

20. The method of claim 19, further comprising transferring a pattern defined by the spacers and the patterned spacer layer into the substrate.

21. The method of claim 19, wherein transferring the pattern defined by the spacers and the patterned spacer layer into the substrate defines interconnects in the substrate.

22. The method of claim 19, wherein the spacer layer is formed of silicon oxide.

23. The method of claim 19, wherein the substrate is part of a partially fabricated memory device.

24. The method of claim 19, wherein the mandrels extend in parallel, regularly spaced-apart lines.

25. The method of claim 19, wherein forming spacers at sidewalls of the mandrels and transferring the photoresist pattern into the spacer layer are performed using a same etch chemistry.