AlSixOy AS A HIGH-TRANSMITTANCE EMBEDDED MATERIAL OF TERNARY ATTENUATED PHASE-SHIFTING MASK AND CORRELATION BETWEEN CHEMICAL COMPOSITION AND OPTICAL PROPERTIES OF AlSixOy IN 193 nm LITHOGRAPHY

• Published in: Jpn.J.Appl.Phys ,Part 1. Vol. 39, no. 12B, pp. 6801-6806. 2000 Vol. 39; no. 12B; pp. 6801 - 6806
• Main Authors: Lin, C-M, Loong, W-A
• Format: Journal Article
• Language: English
• Published: 2000
• ISSN: 0021-4922
• DOI: 10.1143/JJAP.39.6801

AlSixOy (Al:Si:O=1:0.36:0.88) thin film has the potential for use as a new and high-transmittance embedded layer of an attenuated phase-shifting mask (AttPSM) in 193 nm lithography. Increasing the compositions of Al2O3, SiO2, and other oxides increases n and decreases k in AlSixOy. Compared to a conventional AttPSM (T% < 10%), the high-T% AttPSM assisted by opaque Cr scattering bars can achieve a greater depth of focus, 0.45 mu m for a 0.10 mu m isolated line. Under the conditions of BCl3/Cl2=30/7 sccm, chamber pressure 3 mTorr, source power 1400 W and RF bias power 30 W, the etching selectivity of AlSixOy over positive resist EP-1EG is 7.7:1. Under those of BCl3/Cl2/O2=35/7/3.2 sccm, the selectivity of AlSixOy over substrate fused SiO2 is 5.8:1. A 0.25-mu m-line/space (1:1) etched pattern was successfully fabricated using AlSixOy as an embedded layer. 13 refs.