INVESTIGATION ON SURFACE OF BORON-DOPED CVD DIAMOND BY CATHODOLUMINESCENCE SPECTROSCOPY

Boron-doped polycrystalline and homoepitaxial CVD diamond films were i nvestigated by cathodoluminescence (CL) spectroscopy. By CL imaging an d by variation in the electron penetration depth, segregation of the 5 35 mil luminescence center at the growth surface and the interface of Si/diamond was confirmed. After etching by hydrogen plasma, or oxidiza tion by annealing or plasma. the segregation of the 535 nm center stil l remained. Annealing in oxygen or oxidization by plasma induced the b road emission band at 500 nm enhanced in a near surface layer of elect ron penetration depth for 3-5 kV. The 500 nm band appeared remarkably in thin B-doped films with a large quantity of grain boundaries. The b ulging of the 500 nm band was not observed in either homoepitaxial fil ms or undoped films. (C) 1998 Elsevier Science S.A.