GaN films were deposited on sapphire(0001) and Si(100) substrates by MOCVD using an atomic nitrogen source based on a dielectric barrier discharge (DBD) method. Molecule nitrogen and trimethylgallium (TMG) were separately delivered to the substrates. Wurtzite GaN films, with no trace of cubic GaN, were successfully growth on α-Al2O3 substrates even at relatively low temperatures (<800°C). Sapphire substrate RMS roughness was 5.01 and 4.93 angstrom before and after the exposure to DBD N-source, respectively. This shows negligible irradiation damage of accelerated N2+ ion as well as the effect of smoothening the substrate surfaces with DBD N-source. The PL results exhibited small luminescence at the spectral region of blue and UV but a luminescence around the yellow region (2.5 eV) was detected. This is caused by oxygen impurity from AES analysis.
Bibliographical noteFunding Information:
This work was supported by The Korea Science and Engineering Foundation (Grant No. 98-0300-08-01-03) and KIST-2000 Research Program (Grant No. 2V00253).
ASJC Scopus subject areas
- Condensed Matter Physics
- Inorganic Chemistry
- Materials Chemistry