Claims
- 1. A method of forming a dual damascene pattern employing a single phase-shifting mask layer comprising the steps of:
- providing a quartz substrate;
- depositing a layer of metal over said quartz substrate;
- depositing a first layer of photoresist over said layer of metal;
- patterning said first layer of photoresist with a first pattern;
- etching said layer of metal through said first pattern;
- removing said first layer of photoresist;
- depositing a second layer of photoresist over said quartz substrate;
- patterning said second layer of photoresist with a second pattern;
- etching said quartz substrate to a controlled thickness through said second pattern; and
- removing said second layer of photoresist.
- 2. The method of claim 1, wherein said first layer of metal is chromium (Cr).
- 3. The method of claim 1, wherein said first layer of resist is negative type e-beam resist.
- 4. The method of claim 1, wherein said patterning of first layer of e-beam resist is accomplished with a recipe comprising 2.38% TMAH developer in a stream puddle for about 40 to 70 seconds.
- 5. The method of claim 1, wherein said first pattern is a line pattern.
- 6. The method of claim 1, wherein said etching said layer of metal through said first pattern is accomplished with a wet recipe comprising 9%[Cl(NH.sub.4).sub.2 (NO).sub.3 ], 86%[H.sub.2 O] and 5%[Hcl], or dry etch recipe comprising gases Cl.sub.2 and BCl.sub.3 at flow rates between about 30 to 100 and 40 to 100 sccm, respectively.
- 7. The method of claim 1, wherein said second layer of photoresist is negative-type electron-beam resist.
- 8. The method of claim 1, wherein said patterning of second layer of photoresist is accomplished with a recipe comprising developer TMAH and stream puddle for about 40 to 70 seconds.
- 9. The method of claim 1, wherein said second pattern is a hole pattern.
- 10. The method of claim 1, wherein said etching said quartz substrate to a controlled thickness through said second pattern is accomplished with a recipe comprising gases Ar, CHF.sub.3 and C.sub.4 F.sub.8 at a flow rate between about 50 to 150 (sccm), 10 to 50 sccm, and 0 to 22 sccm, respectively.
- 11. The method of claim 1, wherein said controlled thickness is between about 1200 to 2000 angstroms (.ANG.).
- 12. The method of claim 12, wherein said controlled thickness yields a phase shift between about 70 to 110 degrees with light transmittance between about 70 to 34 percent.
RELATED PATENT
U.S. patent application by the same inventor C. M. Dai filed Oct. 14, 1997, Ser. No. 08/949,358, now U.S. Pat. No. 5,935,762, entitled "Two-layered TSI Processes for Dual Damascene Patterning"; filed Oct. 14, 1997, Ser. No. 08/949,350, now U.S. Pat. No. 5,877,075, entitled "Dual Damascene Process Using Single Photoresistk Process"; filed Oct. 14, 1997, Ser. No. 08/949,354, now U.S. Pat. No. 5,882,996, "Self-Aligned Dual Damascene Patterning Using Developer Soluble ARC Interstitial Layer"; and filed Oct. 14, 1997, Ser. No. 08/949,352, now U.S. Pat. No. 5,877,076, entitled "Opposed Two-Layered Photoresist Process for Dual Damascene Patterning", assigned to common assignee.
US Referenced Citations (5)
Non-Patent Literature Citations (1)
Entry |
S. Wolf et al, "Silicon Processing for the VLSI Era" vol. 1, Lattice Press, Sunset Beach, CA, 1986, p. 443. |