Chemical etching using a 1:5:40 HF‐HNO3
COOH solution has been used for the evaluation of hydrogenated amorphous silicon (a
‐Si:H) films. The dissolution rate of a
H films and the structural features brought out by etching have revealed significant differences in the properties of a
‐Si:H films deposited in hydrogen and helium atmospheres. Unintentionally contaminated a
H films have also been found to show considerably higher dissolution rate than intrinsic films, and the dissolution rate measurements may be used to optimize the deposition conditions.