NSF Award
9710628
*** 9710628 Namavar This Small Business Innovation Research Phase II Project is to improve the quality of GaN layers by carbonizing the entire top layer of SIMOX, and to grow GaN by MOCVD on SiC-on-insulator (SiCOI) structures. Phase II will also fabricate extremely high-temperature (HT) n-GaN/p-beta-SiD/n-beta-SiC and n-GaN/p-beta-SiC/n-FaN heterojunction bipolar transistors (HBT's) on large-area compliant SIMOX structures. GaN/beta-SiC/GaN HBT structures will be made by etching the samples from the back and selectively depositing GaN. Phase I results for partially carbonized Si on SIMOX clearly demonstrated the advantage of an SOI structure for growth of beta-SiC. A much narrower rocking curve specta was obtained from SiC grown on SIMOX as compared to that grown on Si.. Rocking curve data, unlike Bragg-Brentano data, are sensitive to the mosaic structure of heteroepitaxial growt, and thus measure crystalline quality. Photoluminescence of MOCVD-grown GaN on SiC/SIMOX shows much stronger purple and weaker yellow emission than GaN on SiC/Si or on sapphire. Also demonstrated was the possibility of selective epitaxial growth of SiC and GaN. HT HBT's are useful for under-the-hood automotive electronics and electronic replacement of avionic hydraulic systems. ***
