Optical properties of Si–O–N–F films as a phase shift mask material for 157 nm optical lithography

• Published in: Optical materials 2003-06, Vol.22 (4), p.361-367
• Main Authors: Kim, Sung Kwan, Kang, Myung Ah, Sohn, Jung Min, Kim, Songho, No, Kwangsoo
• Format: Article
• Language: English
• Subjects: 157 nm; Applied sciences; Circuit properties; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Extinction coefficient; Fabrication techniques; lithography, pattern transfer; Fundamental areas of phenomenology (including applications); Integrated optics. Optical fibers and wave guides; Optical and optoelectronic circuits; Optical materials; Optics; Phase shift mask; Physics; Refractive index; Si–O–N–F; Transmittance
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/S0925-3467(02)00370-1

Si–O–N–F has been studied as a new candidate material for a high transmittance attenuated phase shift mask (HT-Att-PSM). The requirements of HT-Att-PSM are 20 ± 5% transmittance and 180° phase shift at the exposure wavelength (157 nm) and less than 40% transmittance at the inspection wavelength (193 nm). Si–O–N–F films were deposited with varying process parameters, such as gas flow rate and deposition time, to find optimum conditions to meet the above requirements. In this study, the effects of process parameters on the optical properties and the degradation of Si–O–N–F films were examined. To satisfy the requirements of HT-Att-PSM, a new mask structure was suggested and analyzed.