CONTROLLED HYDROGENATION OF AMORPHOUS SILICON AT LOW-TEMPERATURES

Silicon-ion bombardment of crystalline Si and hydrogen-ion implantation are used to produce high-purity amorphous Si with controlled hydrogenation at low temperatures. Hydrogen implanted into amorphous Si chemically bonds predominantly in monohydride (SiH) centers over a wide range of hydrogen concentration. Predominance of monohydride over polyhydride (SiH2) formation in bombardment-produced amorphous Si is independent of the order of hydrogenation and amorphization, and the results suggest that a high disorder level favors monohydride formation. This suggestion is supported by ion-bombardment-induced conversion of SiH2 to SiH1 centers in sputter-deposited films.