Method of forming pattern using fine pitch hard mask

• US 20070123037A1
• Filed: 01/30/2007
• Published: 05/31/2007
• Est. Priority Date: 04/19/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Ji-young, Jeon, Kyung-yub, Kim, Myeong-cheol, Lee, Hak-sun
• Granted Patent: US 7,576,010 B2
• Time in Patent Office: Days
• US Class Current: 438/636
• 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 21/32139 using masks

Abstract

A method of forming a first hard mask pattern including a plurality of first line patterns formed on the etch target layer in a first direction and having a first pitch. A third layer is formed on sidewalls and an upper surface of the first hard mask pattern, such that the third layer includes a top surface having a recess formed between two adjacent first line patterns. A second hard mask pattern including a plurality of second line patterns each extending in the first direction within the recess is formed. Then, the third layer is anisotropically etched to selectively expose an etch target layer between the first line patterns and the second line patterns. Then, the etch target layer is anisotropically etched using the first hard mask pattern and the second hard mask pattern as an etch mask.

Claims

1. A method of forming a fine pattern on a substrate, comprising:

forming a first line on an etch target layer;

forming an anti-reflective layer on the first line;

forming a photoresist pattern on the anti-reflective layer;

anisotropically etching the anti-reflective layer using the photoresist pattern as an etch mask to form a plurality of anti-reflective patterns;

anisotropically etching the first line using the anti-reflective patterns as an etch mask to form a first hard mask pattern comprising a plurality of first line patterns formed on the etch target layer in a first direction and having a first pitch;

forming a third layer on sidewalls and an upper surface of the first hard mask pattern, such that the third layer includes a top surface having a recess formed between two adjacent first line patterns;

forming a second hard mask pattern comprising a plurality of second line patterns each extending in the first direction within the recess;

anisotropically etching the third layer using the first line patterns and the second line patterns as an etch mask to selectively expose the etch target layer between the first line patterns and the second line patterns; and

,

anisotropically etching the etch target layer using the first hard mask pattern and the second hard mask pattern as an etch mask.

2. The method of claim 1, wherein the first line comprises a first layer and a second layer sequentially formed on the etch target layer, the first layer being formed from an oxide, and the second layer being formed from polysilicon.

3. The method of claim 1, wherein the anti-reflective layer comprises a SiON layer.

4. The method of claim 1, wherein the anti-reflective layer comprises an organic anti-reflective coating layer.

5. The method of claim 1, wherein the anti-reflective layer comprises a SiON layer and an organic anti-reflective coating layer sequentially formed on the first line.

6. The method of claim 1, further comprising:

forming a buffer layer on the first line after forming the first line and before forming the anti-reflective layer; and

anisotropically etching the buffer layer using the anti-reflective patterns as an etch mask to form a plurality of buffer patterns on the first line, following formation of the anti-reflective patterns but before formation of the first hard mask pattern.

7. The method of claim 6, wherein the buffer layer comprises a silicon oxide layer.

8. The method of claim 6, wherein the buffer layer comprises an amorphous carbon layer.

9. The method of claim 6, wherein the buffer layer comprises a silicon oxide layer and an amorphous carbon layer sequentially formed on the first line.

10. The method of claim 1, wherein during the formation of the third layer, a plurality of recesses is formed on the top surface of the third layer disposed between the two adjacent first line patterns, and the second line patterns are formed within a grouping of the plurality of recesses.

11. The method of claim 1, wherein the forming of the second hard mask pattern comprises:

forming a fourth layer on the third layer, the fourth layer having a different etch selectivity ratio from that of the third layer; and

forming the second line patterns from remaining portions of the fourth layer within the recess by removing a portion of the fourth layer.

12. The method of claim 11, wherein the portion of the fourth layer is removed using a wet etch method.

13. The method of claim 11, wherein the second line pattern has a width that is one quarter of the first pitch.

14. The method of claim 11, wherein during the formation of the third layer, a plurality of the recesses is formed on the top surface of the third layer, and the fourth layer is completely removed within a grouping of the plurality of recesses during the removal of the portion of the fourth layer.

15. The method of claim 14, wherein the second line patterns are formed within another grouping of the plurality of recesses.

16. The method of claim 1, wherein the first line patterns and the second line patterns are used to form a plurality of line and space patterns on the substrate, each having a pitch that is one half of the first pitch.

17. The method of claim 1, wherein the first line comprises a first layer and a second layer sequentially formed on the etch target layer, and the second line patterns are formed at the same surface level as the second layer.

18. The method of claim 17, wherein the second layer and the second line patterns are formed from the same material.

19. The method of claim 17, wherein the third layer is formed from an oxide, the second layer is formed from a nitride, and second line patterns are formed from polysilicon.

20. The method of claim 19, wherein the third layer is formed from at least one material selected from a group of materials consisting of;

a thermal oxide, a chemical vapor deposition (CVD) oxide, un-doped silicate glass, and a high density plasma oxide.

21. The method of claim 19, wherein the second layer and the second line patterns are formed from at least one material selected from a group of materials consisting of;

SiON, SiN, SiBN, BN, and polysilicon.

22. The method of claim 17, wherein the third layer is formed from a nitride, and the second layer and the second line patterns are formed from an oxide-based material.

23. The method of claim 22, wherein the third layer is formed at least one material selected from a group of materials consisting of;

SiON, SiN, SiBN, and BN.

24. The method of claim 22, wherein the second layer and the second line patterns are formed from at least one material selected from a group of materials consisting of;

silicon on glass and flowable oxide.

25. The method of claim 17, wherein the third layer and the first layer are formed from the same material.

26. The method of claim 17, wherein the third layer and the first layer are formed from different materials.

27. The method of claim 17, wherein the second layer and the second line patterns are formed from different materials.

28. The method of claim 17, wherein the second layer and the second line patterns are formed from the same material.