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Title: Microstructures of GaN and In{sub x}Ga{sub 1-x}N films grown by MOCVD on free-standing GaN templates

Conference ·
OSTI ID:795385

We summarize structural properties of thick HVPE GaN templates from the point of view of their application as substrates for growth of nitride layers. This is followed by the results of optical and structural studies, mostly transmission electron microscopy, of nitride layers grown by MOCVD on top of the HVPE substrates. The results indicate high structural quality of these layers with a low density of threading dislocations (in the range of 10{sup 6} cm{sup -2}). Convergent beam electron diffraction studies showed that the MOCVD GaN films have Ga-polarity, the same polarity as the HVPE GaN substrates. Structural studies of an InGaN layer grown on top of the MOCVD GaN film showed the presence of two layers, which differed in lattice parameter and composition. The upper layer, on the top of the structure had a c-lattice parameter about 2% larger than that of GaN and contained 10.3 {+-} 0.8% of In. Values measured for the thinner, intermediate layer adjacent to the GaN layer were about 2 .5 times lower.

Research Organization:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
Air Force Office of Scientific Research, Order No. AFOSR-ISSA-00-0011 (US)
DOE Contract Number:
AC03-76SF00098
OSTI ID:
795385
Report Number(s):
LBNL-50186; R&D Project: 43CA01; TRN: US200301%%656
Resource Relation:
Conference: 2002 MRS Spring Meeting, San Francisco, CA (US), 04/01/2002--04/05/2002; Other Information: Supercedes report DE00795385; PBD: 30 Apr 2002; Materials Research Society Symposium Proceedings. Vol. 722, pp. 205-210, 2002; PBD: 30 Apr 2002
Country of Publication:
United States
Language:
English