Ion beam synthesis of 3C-SiC layers in Si and its application in buffer layer for GaN epitaxial growth

A 180 keV carbon implantation with an ion dose of 8.0 +/- 1.0 x 10(17) C+/cm(2) into Si(111) wafer has been investigated in order to examine the synthesis of 3C-SiC at the substrate temperature T-s = RT to 800 degreesC and in the subsequent annealing treatment at the temperature T-a = 1000-1250 degreesC/2 h. The combination at T-s approximate to 500 degreesC and at T-a > 1200 degreesC is the most suitable for the synthesis of crystalline 3C-SiC with the same orientation of the Si(111) substrate. The crystalline 3C-SiC layer was used as a buffer layer for the formation of GaN/SiC/Si structure using MOVPE for the GaN growth. After removal of upper layers on the 3C-SiC by chemical etching, a crack-free epitaxial GaN layer of 3 mum thickness has been successfully synthesized. (C) 2004 Elsevier B.V. All rights reserved.