THERMAL-CONDUCTIVITY OF ALPHA-SIH THIN-FILMS

The thermal conductivity of sputtered a-Si:H thin films for a hydrogen content of 1-20 % and a film thickness of 0.2-1.5 mum is determined i n the temperature range 80-400 K using an extension of the 3w measurem ent technique. The reliability of the method is demonstrated on 1-mum- thick a-SiO2 thermally grown on Si. Scattering of phonons at the inter face between the a-Si:H film and the substrate places a simple upper l imit on the heat transport by long-wavelength phonons and facilitates the comparison of the experimental data to recent numerical solutions of a Kubo formula using harmonic vibrations.