Pulsed plasma-enhanced chemical vapor deposition from CH2F2, C2H2F4, and CHCIF2

Pulsed plasma enhanced chemical vapor deposition films have been grown from 1,1,2,2-C2H2F4, CH2F2, and CHClF2. C 1s x-ray photoelectron spectroscopy i ndicates a prevalence of (C) under bar-CF species in the films from C2H2F4 and CH2F2, whereas CF, species dominate the films from CHClF2. The CF, spec ies distributions for the films are largely controlled by the competition b etween CF2-producing and HF elimination reactions in the pulsed plasmas. Do minance by HF elimination produces films with high (C) under bar-CF and CF concentrations (e.g., CH2F2), whereas dominance by CF2-producing reactions leads to films with higher CF2 concentrations (e.g., CHClF2). The % CF3 in the him is lowest for the precursor having the lowest F:H ratio, CH2F2. Lit tle or no hydrogen was detected in the deposited films. Pulsed plasma films from all three precursors gave dielectric constants of 2.4, with loss tang ents on the order of 10(-2). Dielectric measurements of pulsed plasma films from hexafluoropropylene oxide gave a dielectric constant of 2.0+/-0.1 wit h a loss tangent of 0.009. (C) 1999 American Vacuum Society. [S0734-2101(99 )04102-0].