METHOD FOR FABRICATING FINE PATTERN

• US 20120156850A1
• Filed: 09/23/2011
• Published: 06/21/2012
• Est. Priority Date: 12/21/2010
• Status: Active Grant

• Current Assignee: Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Original Assignee: Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Inventors: YANG, Hyun Jo
• Granted Patent: US 8,298,956 B2
• Time in Patent Office: Days
• US Class Current: 438/381
• CPC Class Codes: G03F 1/26 Phase shift masks [PSM]; PSM blanks; Preparation thereof
• CPC Class Codes: G03F 1/70 Adapting basic layout or design of masks to lithographic process requirements, e.g., second iteration correction of mask patterns for imaging
• CPC Class Codes: G03F 7/70283 Mask effects on the imaging process
• CPC Class Codes: G03F 7/70466 Multiple exposures, e.g. combination of fine and coarse exposures, double patterning or multiple exposures for printing a single feature stitching G03F7/70475
• CPC Class Codes: H01L 21/0274 Photolithographic processes
• CPC Class Codes: H01L 21/31144 using masks
• CPC Class Codes: H01L 27/0203 Particular design considerations for integrated circuits
• CPC Class Codes: H10B 63/80 Arrangements comprising multiple bistable or multi-stable switching components of the same type on a plane parallel to the substrate, e.g. cross-point arrays
• CPC Class Codes: H10N 70/011 Manufacture or treatment of multistable switching devices
• CPC Class Codes: H10N 70/063 by etching of pre-deposited switching material layers, e.g. lithography
• CPC Class Codes: H10N 70/231 based on solid-state phase change, e.g. between amorphous and crystalline phases, Ovshinsky effect
• CPC Class Codes: H10N 70/826 adapted for essentially vertical current flow, e.g. sandwich or pillar type devices

Abstract

A method for fabricating a fine pattern includes forming a first photomask including first light transmission regions set in a line shape over a first phase shift mask (PSM) region and a first binary mask (BM) region adjacent to the first phase shift mask region. A second photomask may be formed to include second light transmission regions set in a line shape over a second phase shift mask region and a second binary mask region adjacent to the second phase shift mask region, wherein the second light transmission regions intersect the first light transmission regions. A resist layer may first be exposed using the first photomask and secondly exposed using the second photomask. The first and secondly exposed resist layer may be developed to form resist patterns with open regions corresponding to portions where the first light transmission regions intersect the second light transmission regions.

Claims

1. A method for fabricating a fine pattern, comprising:

forming a first photomask including first light transmission regions set in a line shape over a first phase shift mask (PSM) region and a first binary mask (BM) region adjacent to the first phase shift mask region;

forming a second photomask including second light transmission regions set in a line shape over a second phase shift mask region and a second binary mask region adjacent to the second phase shift mask region, wherein the second light transmission regions intersect the first light transmission regions;

exposing a resist layer using the first photomask;

exposing the resist layer using the second photomask; and

developing the resist layer exposed to the first and second photomasks to form resist patterns with open regions corresponding to portions where the first light transmission regions intersect the second light transmission regions.

2. The method of claim 1, wherein the first phase shift mask region is formed to include a phase shift layer that opens a portion of a transparent substrate of the first photomask corresponding to the first light transmission region located in the first phase shift mask region on the transparent substrate, and the first binary mask region is formed to include a dual layer of a phase shift layer and a light blocking layer, which opens a portion of the transparent substrate of the first photomask corresponding to the first light transmission region located in the first binary mask region on the transparent substrate.

3. The method of claim 1, wherein the first photomask is substantially similar to the second photomask rotated by 90 degrees.

4. The method of claim 1, wherein the first light transmission regions comprise:

first cell light transmission regions repetitively arranged in a line shape; and

a first dummy light transmission region in a line shape arranged outside the first cell light transmission regions, wherein a line width of the first dummy light transmission region is larger than the line width of the first cell light transmission region.

5. The method of claim 1, further comprising:

forming an under layer below the resist layer;

forming hole patterns by etching a portion of the under layer exposed to the resist patterns; and

forming pillars filling the hole patterns.

6. The method of claim 5, wherein, in a phase change memory device including bottom electrodes, phase change layers, and top electrodes, the pillars are formed as the bottom electrodes of the phase change memory device.

7. A method for fabricating a fine pattern, comprising:

forming a first photomask that includes;

a first phase shift mask region including a first phase shift layer with body portions of first light transmission regions having a line shape on a first transparent substrate; and

a first binary mask region including a first light blocking layer with end portions of the first light transmission regions;

forming a second photomask which includes;

a second phase shift mask region including a second phase shift layer with body portions of second light transmission regions having a line shape on a second transparent substrate, wherein the second light transmission regions intersect the first light transmission regions; and

a second binary region including a second light blocking layer with end portions of the second light transmission regions;

forming a resist layer on an under layer;

exposing regions corresponding to the first light transmission regions of the resist layer using the first photomask;

exposing regions corresponding to the second light transmission regions of the resist layer using the second photomask; and

developing the resist layer exposed to the first and second photomasks to form resist patterns with open regions corresponding to portions at intersection of the first and second light transmission regions.

8. The method of claim 7, wherein the first photomask is substantially similar to the second photomask rotated by 90°

.

9. The method of claim 7, wherein the first light transmission regions comprise:

first cell light transmission regions repetitively arranged in a line shape; and

a first dummy light transmission region having a line shape, arranged outside the first cell light transmission regions, wherein a line width of the first dummy light transmission region is larger than the line width of the first cell light transmission region.

10. The method of claim 7, wherein hole patterns are formed at the open regions.

11. The method of claim 10, further comprising forming pillars filling the hole patterns.

12. A method for fabricating a fine pattern, comprising:

forming a first photomask including first cell light transmission regions and a first dummy light transmission region in a line shape extending over a first phase shift mask region and a first binary mask region adjacent to the first phase shift mask region;

forming a second photomask including second cell light transmission regions and a second dummy light transmission region in a line shape extending over a second phase shift mask region and a second binary mask region adjacent to the second phase shift mask region, wherein the second cell light transmission regions and the second dummy light transmission region intersect the first cell light transmission regions and the first dummy light transmission region;

forming a resist layer on an under layer;

exposing the resist layer using the first photomask;

exposing the resist layer using the second photomask;

developing the resist layer exposed to the first and second photomasks to form resist patterns with open regions corresponding to portions where the first cell light transmission regions and the first dummy light transmission region intersect the second cell light transmission regions and the second dummy light transmission region; and

forming cell hole patterns and dummy hole patterns by etching portions of the under layer exposed to the resist patterns.

13. The method of claim 12, wherein the forming of the first and second photomasks comprises:

obtaining a target layout that includes the cell hole patterns and the dummy hole patterns disposed outside the cell hole patterns;

obtaining a layout of the first and second cell light transmission regions and the first and second dummy light transmission regions, in which the cell hole patterns are set by the portions of the first cell light transmission regions that intersect the second cell light transmission regions, and the dummy hole patterns are set by the portions of the first dummy light transmission region that intersect the second cell light transmission regions, the portions of the second dummy light transmission region that intersect the first cell light transmission regions, and the portions of the first dummy transmission regions that intersect the second dummy transmission regions;

setting the first and second phase shift mask regions and the first and second binary mask regions in the layout of the first and second cell light transmission regions and the first and second dummy light transmission regions; and

forming the first photomask using the layout of the first cell light transmission regions and the first dummy light transmission region, and forming the second photomask using the layout of the second cell light transmission regions and the second dummy light transmission region.

14. The method of claim 12, wherein the first phase shift mask region is formed to include a phase shift layer that opens a portion of a transparent substrate of the first photomask corresponding to the first cell light transmission region that is located in the first phase shift mask region on the transparent substrate, and the first binary mask region is formed to include a dual layer of a phase shift layer and a light blocking layer, which opens a portion of the transparent substrate of the first photomask corresponding to the first light transmission region that is located in the first binary mask region on the transparent substrate.

15. The method of claim 12, wherein a line width of the first and second dummy light transmission regions is larger than a line width of the first and second cell light transmission regions.

16. The method of claim 12, further comprising forming pillars filling the cell hole patterns and the dummy hole patterns.