EBIC OBSERVATION OF N-GAN GROWN ON SAPPHIRE SUBSTRATES BY MOCVD

Si-doped GaN layers were grown on sapphire substrates by metalorganic chemical vapor deposition (MOCVD) and characterized by using electron beam-induced current (EBIC) and molten KOH etching. Dark spot densitie s in EBIC image are be 1.0 and 1.2 x 10(8) cm(-2) depending on the acc elerating voltage. The dark spots in EBIC image correspond to recombin ation centers. When we compare dark spot density with etch pit density revealed molten KOH, this is the same order as the EPD revealed by mo lten KOH. We confirm there are many dislocations which influence recom bination of minority carriers in the layers. (C) 1998 Elsevier Science B.V. All rights reserved.