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用自组装的氨源分子束外延 (NH3-MBE)系统和射频等离子体辅助分子束外延 (PA-MBE)系统在 C面蓝宝石衬底上外延了优质 Ga N以及 Al Ga N/Ga N二维电子气材料。Ga N膜 (1 .2 μm厚 )室温电子迁移率达3 0 0 cm2 /V· s,背景电子浓度低至 2× 1 0 1 7cm- 3。双晶 X射线衍射 (0 0 0 2 )摇摆曲线半高宽为 6arcmin。 Al Ga N/Ga N二维电子气材料最高的室温和 77K二维电子气电子迁移率分别为 73 0 cm2 /V·s和 1 2 0 0 cm2 /V· s,相应的电子面密度分别是 7.6× 1 0 1 2 cm- 2和 7.1× 1 0 1 2 cm- 2 ;用所外延的 Al Ga N/Ga N二维电子气材料制备出了性能良好的 Al Ga N/Ga N HFET(异质结场效应晶体管 ) ,室温跨导为 5 0 m S/mm(栅长 1 μm) ,截止频率达 1 3 GHz(栅长 0 .5μm)。该器件在 3 0 0°C出现明显的并联电导 ,这可能是材料中的深中心在高温被激活所致
High-quality Ga N and Al Ga N / Ga N two-dimensional (2D) GaAs films were epitaxially grown on C-plane sapphire substrates by a self-assembled ammonia source molecular beam epitaxy (NH3-MBE) system and a radio frequency plasma-assisted molecular beam epitaxy (PA- Electronic gas materials. The electron mobility of Ga N film (1.2 μm thick) at room temperature is 300 cm 2 / V · s and the background electron concentration is as low as 2 × 10 7 cm -3. The FWHM (0 0 0 2) rocking curve FWHM is 6 arcmin. The highest room-temperature and 77K two-dimensional electron gas electron mobility of AlGaN / GaN two-dimensional electron gas materials were 73 0 cm2 / V · s and 12 0 0 cm2 / V · s respectively. The corresponding electronic surface densities were 7.6 × 10 12 cm -2 and 7.1 × 10 12 cm -2. The Al Ga N / Ga N HFET with good properties was prepared by using the epitaxial Al Ga N / Ga N two-dimensional electron gas Quality junction field effect transistor) with a transconductance of 50 mS / mm (gate length 1 μm) at room temperature and a cut-off frequency of 13 GHz (gate length 0.5 μm). The device exhibits significant parallel conductance at 300 ° C, which may be due to activation of the deep center of the material at high temperatures