Claims
- 1. A method for reducing distortion in charged particle lithographic masks, comprising the steps of:
adding a dummy fill shape in an unexposed region of a mask; and applying a blocking layer to the region of the dummy fill shape.
- 2. The method of claim 1 wherein the blocking layer is an aperture.
- 3. The method of claim 2 where the step of applying further comprises sliding an aperture over the dummy shape.
- 4. The method of claim 2 wherein the aperture is adjustable.
- 5. The method of claim 1 where the step of applying blocking layer occurs by using a second mask with an opaque region where the dummy fill shape is.
- 6. The method of claim 1 where the step of applying the blocking layer occurs by depositing a low stress material that covers the dummy fill shape.
- 7. The method of claim 1 where the step of applying the blocking layer occurs by forming a second membrane layer on the mask and patterning the membrane.
- 8. The method of claim 7 wherein the blocking layer is created by using a SOI starting substrate.
- 9. The method of claim 1 where the step of applying the blocking layer occurs after a stencil mask is fabricated.
- 10. The method of claim 9 where the blocking layer is fabricated by first applying thin support layer over the stencil mask.
- 11. A charged particle lithographic device, which comprises:
a dummy shape in an unexposed region of a mask; and a blocking layer covering the dummy shape in such a manner as to prevent the dummy shape from printing
- 12. The device of claim 11, wherein the blocking layer is a structure separate from the mask.
- 13. The device of claim 12, wherein the separate structure is an aperture.
- 14. The device of claim 12, wherein the separate structure is an additional mask.
- 15. The device of claim 13, wherein, the aperture is adjustable.
- 16. The device of claim 14 wherein the additional mask has an opaque region where the dummy fill shape is.
- 17. The device of claim 11 wherein the blocking layer is a low stress material deposited in a region on the mask covering the dummy fill shape.
- 18. The device of claim 11 wherein the blocking layer is deposited on a second membrane layer on the mask.
- 19. The device of claim 18 wherein the blocking layer is created by using a SOI starting substrate.
- 20. The method of claim 9 wherein the blocking layer is fabricated on a stencil mask.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0001] This invention was made with U.S. Government support under Agreement No. N00019-99-3-1366 awarded by the Naval air Systems Command. The U.S. Government has certain rights in the invention.