Impurity doping in chemically vapor-deposited amorphous hydrogenated silicon from disilane

Abstract

Physical properties of amorphous hydrogenated silicon produced by the chemical vapor deposition (CVD) of disilane have been investigated as a function of doping ratio of phosphine or diborane. The growth rate is decreased by phosphine doping and increased by boron doping. It is found that the electrical conductivity can be controlled over a wide range by phosphorus or boron doping. The optical band gap is lowered by doping as a result of decrease in hydrogen content. Also, a wide band gap of a-SixN1−x:H has been prepared by CVD of a Si2H6+NH3 gas mixture.