Effects of Hydrogen Plasma Treatment on Hydrogenated Amorphous Silicon

Abstract

ABSTRACTWe have studied the effects of hydrogen plasma treatments of a-Si:H at elevated temperatures using conductivity, photoconductivity, and spin density measurements. Effects were measured as a function of temperature and of treatment time; control specimens were subjected to comparable treatments without the plasma. In no case did plasma treatment improve the specimen photoconductivity over the as-deposited state. At treatment temperatures (230 °C < T < 460 °C) plasma treatment reduced the photoconductivity below that of the control specimen. This effect may be evidence for plasma-assisted dehydro-genation of the specimen. The defect structural equilibration determined by hydrogen chemical potential depending on temperature and hydrogen plasma is also addressed.