Claims
- 1. A method for forming an x-ray mask using a tungsten film absorber, comprising the steps of:
- depositing an oxide layer on a top side of a substrate;
- forming trenches in said oxide layer defining an x-ray mask pattern;
- sputtering collimated tungsten into said trenches to completely fill said trenches;
- removing excess tungsten to make said trenches flush with said oxide layer;
- removing said substrate starting from a bottom side of said substrate to minimize substrate thickness.
- 2. A method for forming an x-ray mask as recited in claim 1 wherein said step of removing leaves a layer of said substrate at most approximately 2 .mu.m thick.
- 3. A method for forming an x-ray mask as recited in claim 1 wherein said step of removing is etching.
- 4. A method for forming an x-ray mask as recited in claim 1 wherein said sputtering step is performed at a pressure between 12 to 18 mT.
- 5. A method for forming an x-ray mask as recited in claim 1 wherein removing excess tungsten step is performed by polishing.
- 6. A method for forming an x-ray mask as recited in claim 1 wherein said step of forming trenches in said oxide layer comprises forming trenches having varying depths for realizing a grey level x-ray mask.
- 7. A method of forming an x-ray mask as recited in claim 1 wherein said oxide layer is deposited using a tetraethyl orthosilicate (TEOS) source.
- 8. A damascene tungsten absorber x-ray mask, made by the process comprising the steps of:
- forming on a top side of a substrate an oxide layer, said oxide layer having trenches formed therein defining an x-ray mask pattern, said oxide layer being transparent to x-rays;
- depositing a collimated tungsten film filling said trenches, said collimated tungsten film being opaque to x-rays; and
- removing a portion of said substrate from a bottom side.
- 9. A damascene tungsten absorber x-ray mask as recited in claim 8 wherein said substrate is approximately 2 .mu.m thick after said step of removing.
- 10. A damascene tungsten absorber x-ray mask, as recited in claim 8 wherein said trenches are of varying depths for realizing a grey level x-ray mask.
- 11. A damascene tungsten absorber x-ray mask as recited in claim 8 wherein said collimated tungsten film is sputter deposited at a gas pressure of 12-18 mT.
- 12. A grey scale x-ray mask, comprising:
- an oxide layer having a plurality of trenches formed therein defining an x-ray mask pattern, said oxide layer being transparent to x-rays;
- a plurality of x-ray absorber materials of varying x-ray transparency filling various ones of said plurality of trenches.
- 13. A grey scale x-ray mask as recited in claim 12 wherein said oxide layer is tetraethyl orthosilicate (TEOS).
- 14. A grey scale x-ray mask as recited in claim 12 wherein one of said plurality of x-ray absorber materials is tungsten.
Parent Case Info
This application is a continuation of U.S. patent application Ser. No. 08/486,219, filed Jun 7, 1995, now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (4)
Number |
Date |
Country |
0440377A2 |
Aug 1991 |
EPX |
512296A1 |
Nov 1992 |
EPX |
5326426 |
Aug 1992 |
JPX |
5243181 |
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JPX |
Non-Patent Literature Citations (2)
Entry |
"High-resolution and high-fidelity x-ray mask structure employing embedded absorbers"; S.Y. Chou et al.; J. Vac. Science, Nov./Dec. 1988. |
"EB Proximity Printer With Increased Throughput"; K. Asch et al.; IBM Technical Disclosure Bulletin; vol. 26, No. 2, Jul. 1983. |
Continuations (1)
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Number |
Date |
Country |
Parent |
486219 |
Jun 1995 |
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