Observation of a two-dimensional electron gas in the AlGaN/GaN on SiC substrates
- National Central Univ., Chungli (Taiwan, Province of China). Dept. of Physics
- National Chiao Tung Univ., Hsinchu (Taiwan, Province of China)
GaN/Al{sub 0.08}Ga{sub 0.92}N heterostructure has been grown on(0001) 6H-SiC substrates using low pressure metalorganic chemical vapor deposition (LP-MOCVD). Triethylgallium (TEGa), trimethylaluminum (TMA) and ammonia (NH{sub 3}) were used as the Ga, Al and N sources, respectively. The carrier gas is hydrogen(H{sub 2}) and the growth pressure is kept at 76 torr. Five pairs of GaN/Al{sub 0.08}Ga{sub 0.92}N(100{angstrom}/100{angstrom}) were used as buffer layer, then followed by an 1.3 {micro}m GaN film. The 500{angstrom} AlGaN bulk structure was grown on the GaN and finally an 100{angstrom} GaN cap layer to prevent the oxidation of AlGaN layer. The full width half maxima(FWHM) of x-ray peak is 115 arc second for the thick layer of GaN (1.3 {micro}m), this value is smaller than they reported for the GaN on sapphire substrate (it was about 300 arc second). The Hall mobility and sheet carrier concentration are 887 cm{sup 2}/Vs, 1.0 {times} 10{sup 16} cm{sup {minus}2} at 300 K and 4,661 cm{sup 2}/Vs, 7.2 {times} 10{sup 12} cm{sup {minus}2} at 77K. This high electron mobility is an indication of a two-dimensional electron gas(2DEG) formed at the GaN/AlGaN interface.
- OSTI ID:
- 581126
- Report Number(s):
- CONF-961202--; ISBN 1-55899-353-3
- Country of Publication:
- United States
- Language:
- English
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