EFFECT OF ANNEALING ON THE DEFECT STRUCTURE IN A-SIC-H FILMS

The annealing behavior of amorphous, hydrogenated silicon carbide film s in the range 400-900 degrees C was studied by optical characterizati on methods, N-15 hydrogen profiling, and defect profiling using a vari able energy positron beam. The films were deposited in an electron cyc lotron resonance chemical vapor deposition system using ditertiary but yl silane [SiH2(C4H9)(2)] as the monosource for silicon and carbon. As -deposited films were found to contain large concentrations of hydroge n, both bonded and unbounded. Under rapid thermal annealing in a N-2 a tmosphere, the bonded hydrogen effuses giving rise to additional Si-C bond formation and to film densification. After annealing at high temp eratures in N-2, a marked decrease in the total hydrogen content is ob served. After annealing in vacuum, however, the hydrogen effusion prom otes void formation in the films. (C) 1996 American Institute of Physi cs.