InP基RTD/HEMT集成的几个关键工艺研究

用MBE设备在半绝缘的InP衬底上依次生长高电子迁移率晶体管(HEMT)外延材料和共振遂穿二极管(RTD)外延材料,在此材料结构基础上研究和分析了RTD与HEMT器件单片集成工艺中的隔离工艺、欧姆接触工艺、HEMT栅挖槽工艺和空气桥工艺等几步关键工艺,给出了这些工艺的相关参数。利用上述工艺成功地制作了RTD和HEMT器件,并在室温下分别测试了RTD器件和HEMT器件的电学特性。测试表明:在室温下,RTD器件的峰电流密度与谷电流密度之比(PVCR)为3.66;HEMT器件的最大跨导约为370 mS/mm,在Vds=1.5 V时的饱和电流约为391 mA/mm。这将为RTD与HEMT的单片集成研究奠定工艺基础。

Several Key Processes for InP-based Integration of Resonant Tunneling Diodes and High Electron Mobility Transistors

The epitaxial layers of the resonant tunneling diodes(RTD) and high electron mobility transistors(HEMT) were grown on semi-insulating InP substrates by Molecular Beam Epitaxy(MBE).The key fabrication processes of the integration of RTD devices and HEMT devices were systematically investigated and analyzed,such as the isolation technology,the ohmic contact technology,the chamfer of the HEMT gate and the air-bridge technology on the new material structure,and the processes parameters were given.Besides,the RTD devices and HEMT devices are fabricated successfully by using these processes,and the electronical characteristics of fabricated RTD devices and HEMT devices at room temperature were tested,respectively.These results show that the peak-to-valley current density ratio(PVCR) of RTD is 3.66,the maximum transconductance of HEMT is 370 mS/mm and the saturated current at Vds=1.5 V is 391 mA/mm.The research will be helpful to establish the complete processes for integration of RTD devices and HEMT devices.