AN INSIGHT INTO THE MECHANISM OF SURFACE CONDUCTIVITY IN THIN-FILM DIAMOND

Diamond containing hydrogen at or near the surface displays p-type con ductivity. The origin of this effect has been controversial. We have u sed I-V, Hall effect, SIMS, Raman, UPS and XPS to study hydrogenated p olycrystalline CVD diamond films. The direct formation of acceptor sta tes by hydrogen, which resides within the top 20 nm of the film, is th e origin of the carriers present rather than surface band bending. Up to 10(19) holes cm(-3) can be measured and mobilities as high as 70 cm (2) Vs(-1) recorded. H-termination of the surface is important for the formation of high quality metal-diamond interfaces. (C) 1998 Elsevier Science S.A.