SURFACE MODIFICATION OF A-SIC THIN-FILMS WITH EX-SITU HYDROGENATION

We present a study of surface modifications induced in a-SiC thin film s grown by sputtering and subjected to ex-situ hydrogenation in a radi ofrequency hydrogen glow discharge. Measurements of X-ray photoelectro n spectroscopy, optical reflectivity and X-Ray diffraction lead to the conclusion that atomic hydrogen causes preferential etching of silico n from the surface and promotes the formation of a surface polycrystal line hydrogenated carbon layer with a small oxygen content. Furthermor e, surface characterisation using scanning electron microscopy and ato mic force microscopy shows that the surface carbon layer is grooved. T he groves form angles with values very close to those of a hexagonal s tructure and they have an average peak-to-peak height of 20+/-5nm.