Hydride-vapor-phase epitaxial growth of highly pure GaN layers with smooth as-grown surfaces on freestanding GaN substrates
Hydride-vapor-phase epitaxial growth of highly pure GaN layers with smooth as-grown surfaces on freestanding GaN substrates
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DOI：
10.7567/jjap.56.085503
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发表时间：
2017-07
影响因子：
1.5
通讯作者：
H. Fujikura;Taichiro Konno;Takehiro Yoshida;F. Horikiri
中科院分区：
文献类型：
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作者：
H. Fujikura;Taichiro Konno;Takehiro Yoshida;F. Horikiri
利用我们先进的氢化物-气相外延（HVPE）系统，在独立GaN衬底上制备了厚（20-30 μ m）的高纯度GaN层，其表面光滑，具有器件质量。从HVPE系统中去除石英部分显着降低了残留杂质的浓度，低于二次离子质谱法检测的极限。在HVPE系统中，适当的气流管理实现了设备质量、光滑、生长表面和极好的厚度均匀性。未掺杂的氮化镓层具有绝缘性能。通过Si掺杂，电子浓度可控制在2 × 1014 cm−3的较宽范围内，最大迁移率为1150 cm2·V−1·s−1。在整个2-in中，轻硅掺杂层的残留深能级浓度在1014 cm−3范围内或更小。晶片表面。这些成就清楚地证明了HVPE作为功率器件结构外延生长工具的潜力。
Thick (20–30 µm) layers of highly pure GaN with device-quality smooth as-grown surfaces were prepared on freestanding GaN substrates by using our advanced hydride-vapor-phase epitaxy (HVPE) system. Removal of quartz parts from the HVPE system markedly reduced concentrations of residual impurities to below the limits of detection by secondary-ion mass spectrometry. Appropriate gas-flow management in the HVPE system realized device-quality, smooth, as-grown surfaces with an excellent uniformity of thickness. The undoped GaN layer showed insulating properties. By Si doping, the electron concentration could be controlled over a wide range, down to 2 × 1014 cm−3, with a maximum mobility of 1150 cm2·V−1·s−1. The concentration of residual deep levels in lightly Si-doped layers was in the 1014 cm−3 range or less throughout the entire 2-in. wafer surface. These achievements clearly demonstrate the potential of HVPE as a tool for epitaxial growth of power-device structures.