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

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This item was taken from the IEEE Conference ' Comparative study of low-temperature PECVD Of amorphous silicon using mono-, di-, trisilane and cyclohexasilane ' The hydrogenated amorphous silicon a-Si6H films were grown by plasma-enhanced chemical vapor deposition (PECVD) using liquid cyclohexasilane Si6H12 (CHS). The growth rate of a-Si6H was studied as a function of substrate temperatures in the range of 30 �CjTj450 �C using deposition conditions that were optimized for monosilane SiH4. The same parameters were used for a- Si6H films grown using disilane (Si2H6) and trisilane (Si3H8) precursors. It was found that the a-Si6H film growth rate of CHS is lower with respect to those of mono-, di- and trisilane in an Ar plasma. Addition of <10% of H2 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/H2 mixtures as carrier gas have a reduced hydrogen content relative to polysilane fragments indicating higher quality amorphous silicon.