COMPARATIVE-STUDY OF PROPERTIES BETWEEN A-GEC-H AND A-SIC-H FILMS PREPARED BY RADIOFREQUENCY REACTIVE SPUTTERING IN METHANE

Hydrogenated amorphous germanium-carbon (a-GeC:H) and silicon-carbon (a-SiC:H) films were deposited by reactive magnetron sputtering of Ge and Si targets in a methane argon gas mixture. The effect of rf power on the structural, optical, and electrical properties of the films was investigated. The carbon content in a-SiC:H films is larger than in a-GeC:H for the same deposition condition, and it decreases with increasing rf power. The intensity of the carbon-related bonds, the optical band gap, and the activation energy of de conductivity of both films decreases with decreasing carbon content. The temperature dependence of de conductivity of a-SiC:R exhibits activated-type conduction, whereas hopping conduction is predominant in a-GeC:H. Hydrogen concentration and H bonding ratio are examined, indicating that the termination of the dangling bond by hydrogen is more effective in a a-SiC:H films than a-GeC:H films. (C) 1995 American Institute of Physics.