Material properties and growth process of microcrystalline silicon with growth rates in excess of 1 nm/s

Abstract

ABSTRACTThe expanding thermal plasma (ETP) has been used to deposit microcrystalline silicon (µc-Si:H) with rates up to 2.7 nm/s. Typical material properties of well crystallised material are crystallite sizes of 20 nm, photo- and dark conductivity of 2×10−5 and 2x10−7 S/cm respectively, and an activation energy of 600 meV. The radical densities of SiH3, SiH, and Si present in the gas phase have been quantified. In conditions where [.proportional µc-Si:H is deposited the atomic hydrogen flux towards the surface is of the same magnitude or higher as the flux of deposited radicals. Furthermore, the abundance of radicals such as SiH and Si is large and may contribute several tens of percent to the deposition rate.