Comparative study of low-temperature PECVD Of amorphous silicon using mono-, di-, trisilane and cyclohexasilane

• Published in: 2009 34th IEEE Photovoltaic Specialists Conference (PVSC) pp. 001758 - 001760
• Main Authors: Pokhodnya, K., Sandstrom, J., Olson, C., Xuliang Dai, Boudjouk, P.R., Schulz, D.L.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.06.2009
• Subjects: Amorphous silicon; Argon; Chemical vapor deposition; Hydrogen; Plasma chemistry; Plasma temperature; Raman scattering; Semiconductor films; Substrates; Temperature distribution
• ISBN: 1424429498; 9781424429493
• ISSN: 0160-8371
• DOI: 10.1109/PVSC.2009.5411459

The hydrogenated amorphous silicon a-Si:H films were grown by plasma-enhanced chemical vapor deposition (PECVD) using liquid cyclohexasilane Si 6 H 12 (CHS). The growth rate of a-Si:H was studied as a function of substrate temperatures in the range of 30 °C<T<450°C using deposition conditions that were optimized for monosilane SiH 4 . The same parameters were used for a- Si:H films grown using disilane (Si 2 H 6 ) and trisilane (Si 3 H 8 ) precursors. It was found that the a-Si:H film growth rate of CHS is lower with respect to those of mono-, di- and trisilane in an Ar plasma. Addition of ~10% of H 2 dramatically increases the deposition rate for CHS-based films about 700% to 8 ¿/sec. The as-deposited films were characterized by FTIR and Raman spectroscopy to probe the hydrogen content and local bonding environment. It was found that the films grown using Ar/H 2 mixtures as carrier gas have a reduced hydrogen content relative to polysilane fragments indicating higher quality amorphous silicon.