A study of hydrogenated amorphous silicon deposited by hot-wall glow discharge

Abstract

We report a study of a-Si:H films deposited in a hot-wall glow-discharge machine. Optical and transport properties were studied as a function of frequency (400 kHz and 13.56 MHz) and power of the radio frequency (rf), temperature and pressure during deposition, and they were found very similar to those of films deposited by other glow-discharge techniques. Thin films (<1 μm) have a higher defect density than thicker films. The lowest defect density and disorder are achieved in the 200–250 °C temperature range. Pressure and rf frequency have no effect on defect density and disorder but control the position of the Fermi level. Reversible defect creation is induced by long and intense light irradiation but this induces no shift of the Fermi level.