Abstract
Mixed phase of amorphous and microcrystalline silicon-hydrogen alloys has been fabricated by reactive sputtering in He containing H2 of which mole fraction is less than about 5 mole%. The degree of the crystallization, evaluated by electron microscopy and optical absorption spectroscopy, becomes high as the amount of H2 in the atmosphere increases. The conductivity in dark and photoconductivity increase as the partial pressure of H2 increases (from 0 to 1 mole%) and also as the pressure during sputtering increases. This increase in conductivity and photoconductivity is supposed to be related to the development of microcrystals. The highest photoconductivity is observed at the H2 mole fraction of about 1 mole%. This film contains a small amount of microcrystals and show the photoconductivity higher by 2 orders of magnitude than that in a film sputter-deposited in Ar and H2 atmosphere in the same apparatus.
