SELF-ALIGNED PILLAR PATTERNING USING MULTIPLE SPACER MASKS

• US 20090017631A1
• Filed: 05/13/2008
• Published: 01/15/2009
• Est. Priority Date: 06/01/2007
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Bencher, Christopher D.
• Application Number:
  US12/119,836
• Publication Number:
  US 20090017631A1
• Time in Patent Office: Days
• US Class Current: 438/703
• CPC Class Codes: H01L 21/0334 characterised by their size, orientation, disposition, behaviour, shape, in horizontal or vertical plane
• CPC Class Codes: H01L 21/0338 Process specially adapted to improve the resolution of the mask

Abstract

A method for fabricating a semiconductor mask is described. The image of a series of lines from a first spacer mask is first provided to a mask layer to form a patterned mask layer. The image of a series of lines from a second spacer mask is then provided to the patterned mask layer to form a pillar mask comprised of a series of pillars. The image of the series of lines from the second spacer mask is non-parallel with the series of lines from the first spacer mask.

Claims

1. A method for fabricating a semiconductor mask, comprising:

providing the image of a series of lines from a first spacer mask to a mask stack to form a patterned mask stack; and

providing the image of a series of lines from a second spacer mask to said patterned mask stack to form a pillar mask comprised of a series of pillars, wherein the image of said series of lines from said second spacer mask is non-parallel with the image of said series of lines from said first spacer mask.

2. The method of claim 1 wherein the image of said series of lines from said second spacer mask is orthogonal with the image of said series of lines from said first spacer mask, and wherein each pillar of said pillar mask has a square shape.

3. The method of claim 1 wherein the image of said series of lines from said second spacer mask is at an angle θ

relative to the image of said series of lines from said first spacer mask, wherein 45°

<

θ

<

90°

, and wherein each pillar of said pillar mask has a diamond shape.

4. The method of claim 1 wherein said mask stack comprises a layer of amorphous carbon film.

5. A method for fabricating a semiconductor mask, comprising:

providing a semiconductor structure having a first sacrificial mask comprised of a first series of lines above a mask stack;

forming a first spacer mask having spacer lines adjacent to the sidewalls of said first series of lines of said first sacrificial mask;

removing said first sacrificial mask; and

, subsequently,

providing the image of the spacer lines from said first spacer mask to said mask stack to form a patterned mask stack;

forming a second sacrificial mask comprised of a second series of lines above said patterned mask stack;

forming a second spacer mask having spacer lines adjacent to the sidewalls of said second series of lines of said second sacrificial mask, wherein the spacer lines of said second spacer mask are non-parallel with the image of the spacer lines from said first spacer mask in said patterned mask stack;

removing said second sacrificial mask; and

, subsequently,

providing the image of the spacer lines from said second spacer mask to said patterned mask stack to form a pillar mask stack comprised of a series of pillars.

6. The method of claim 5 wherein the spacer lines of said second spacer mask are orthogonal with the image of the spacer lines from said first spacer mask in said patterned mask layer, and wherein each pillar of said pillar mask stack has a square shape.

7. The method of claim 5 wherein the spacer lines of said second spacer mask are at an angle θ

relative to the image of the spacer lines from said first spacer mask in said patterned mask layer, wherein 45°

<

θ

<

90°

, and wherein each pillar of said pillar mask stack has a diamond shape.

8. The method of claim 5 wherein the frequency of the spacer lines of said first spacer mask is double the frequency of said first series of lines of said first sacrificial mask.

9. The method of claim 8 wherein the pitch of said first series of lines of said first sacrificial mask is approximately 4.

10. The method of claim 9 wherein the frequency of the spacer lines of said second spacer mask is double the frequency of said second series of lines of said second sacrificial mask.

11. The method of claim 10 wherein the pitch of said second series of lines of said second sacrificial mask is approximately 4.

12. The method of claim 5 wherein said mask stack comprises a layer of amorphous carbon film.

13. A method for fabricating a semiconductor mask, comprising:

providing a semiconductor structure having a first sacrificial mask comprised of a first series of lines above a mask stack;

depositing a first spacer layer above said semiconductor structure and conformal with said first sacrificial mask;

etching said first spacer layer to provide a first spacer mask having spacer lines adjacent to the sidewalls of said first series of lines of said first sacrificial mask;

removing said first sacrificial mask; and

, subsequently,

providing the image of the spacer lines from said first spacer mask to said mask stack to form a patterned mask stack;

forming a second sacrificial mask comprised of a second series of lines above said patterned mask stack;

depositing a second spacer layer above said patterned mask stack and conformal with said second sacrificial mask;

etching said second spacer layer to provide a second spacer mask having spacer lines adjacent to the sidewalls of said second series of lines of said second sacrificial mask, wherein the spacer lines of said second spacer mask are non-parallel with the image of the spacer lines from said first spacer mask in said patterned mask stack;

removing said second sacrificial mask; and

, subsequently,

providing the image of the spacer lines from said second spacer mask to said patterned mask stack to form a pillar mask stack comprised of a series of pillars.

14. The method of claim 13 wherein the spacer lines of said second spacer mask are orthogonal with the image of the spacer lines from said first spacer mask in said patterned mask layer, and wherein each pillar of said pillar mask stack has a square shape.

15. The method of claim 13 wherein the spacer lines of said second spacer mask are at an angle θ

relative to the image of the spacer lines from said first spacer mask in said patterned mask layer, wherein 45°

<

θ

<

90°

, and wherein each pillar of said pillar mask stack has a diamond shape.

16. The method of claim 13 wherein the frequency of the spacer lines of said first spacer mask is double the frequency of said first series of lines of said first sacrificial mask.

17. The method of claim 16 wherein the pitch of said first series of lines of said first sacrificial mask is approximately 4.

18. The method of claim 17 wherein the frequency of the spacer lines of said second spacer mask is double the frequency of said second series of lines of said second sacrificial mask.

19. The method of claim 18 wherein the pitch of said second series of lines of said second sacrificial mask is approximately 4.

20. The method of claim 13 wherein said mask stack comprises a layer of amorphous carbon film.