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Accession Number:
ADA280988
Title:
Nitride Semiconductors for Ultraviolet Detection
Descriptive Note:
Semiannual technical rept. 1 Jan 1994-30 Jun 1994
Corporate Author:
NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATERIALS SCIENCE AND ENGINEERING
Report Date:
1994-06-01
Pagination or Media Count:
26.0
Abstract:
Monocrystalline GaN thin films have been grown on vicinal alpha6H- SiC0001 and sapphire0001 wafers via organometallic vapor phase epitaxy OMVPE using a cold-wall, vertical barrel reactor with triethylgallium TEG and ammonia. Chemical, analytical and microstructural studies revealed epitaxial films of high microstructural quality. The surface morphologies and photoluminescence spectroscopy PL spectra of GaN films on both substrates are presented and described. Specifically, the PL data revealed donor bound exciton emission at 357.6nm for films thicker than 1 mm. Two other emission peaks at 375-378 nm and 540 nm were common to all films tested. Hall effect measurements showed that the unintentionally doped films were highly n-type with a mobility of approx. 40 sq cmVdots. The new method for the growth of the III-V compounds, namely, the use on an ammonia cracker cell to minimize film damage and increase growth rate has been designed and ordered. Preliminary studies of the use of AlN as a candidate insulator material has been conducted via the fabrication of an MIS structure. I-V and high frequency C-V measurements revealed a 13.4 MVcm breakdown field and a dielectric constant of approx. 14. Operation of the MIS devices at 300 deg C with only a slight reduction in the breakdown field to 13 MVcm.
Distribution Statement:
APPROVED FOR PUBLIC RELEASE
