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在研制AlGaN/GaNHEMT器件的基础上,采用ALD法制备了Al2O3AlGaN/GaNMOSHEMT器件.通过X射线光电子能谱测试表明在AlGaN/GaN异质结材料上成功淀积了Al2O3薄膜.根据对HEMT和MOSHEMT器件肖特基电容、器件输出以及转移特性的测试进行分析发现:所制备的Al2O3薄膜与AlGaN外延层间界面态密度较小,因而MOSHEMT器件呈现出较好的栅控性能;其次,该器件的栅压可以加至+3V,此时的最大饱和电流达到800mA/mm,远远高于肖特基栅HEMT器件的最大输出电流;而且栅漏反偏状态下的泄漏电流却减小了两个数量级,提高了器件的击穿电压,通过进一步分析认为泄漏电流主要来源于Fowler-Nordheim隧穿.
Al 2 O 3 AlGaN / GaNMOSHEMT devices were prepared by ALD method on the basis of AlGaN / GaNHEMT devices.The results of X-ray photoelectron spectroscopy showed that the Al 2 O 3 thin films were successfully deposited on AlGaN / GaN heterojunction materials.According to the HEMT and MOSHEMT devices Schottky capacitance, device output and transfer characteristics of the test analysis found that: the prepared Al 2 O 3 thin film and the AlGaN epitaxial layer interface state density is small, so the MOSHEMT device shows good gate control performance; second, the device gate The voltage can be increased to + 3V, at which point the maximum saturation current reaches 800mA / mm, which is much higher than the maximum output current of Schottky barrier HEMT devices. And the leakage current in the reverse gate-drain state is reduced by two orders of magnitude , Which improves the breakdown voltage of the device. After further analysis, the leakage current mainly comes from Fowler-Nordheim tunneling.