The Study Of Device Characterization And Process Technology For InAs/AlSb HEMTs

As the represent of Sb-based compound semiconductor devices, InAs/AlSbHEMTs with high electron mobility, low power consumption and good noise figure aregoing to be the next generation of high speed devices after InP-based device. They willbe competitive devices in the areas of high speed, low consumption applications.In this thesis, necessary research work has been made to get a InAs/AlSb HEMTdevice. First of all, important parameters of the device are analyzed and the history ofInAs/AlSb HEMT devices is introduced. On the basis of these, material structures aredesigned and grew. In order to improve the density of two-dimension electrongas(2DEG) and the mobility of electrons, material of four different kinds of structuresare grew. Atomic force microscope, Hall measurement and C-V are used to evaluatethe quality of epitaxial wafers. The results show that material of#3structure has aconcentrated channel2DEG density of8.55×1011cm-2,electron mobility of25318cm2/V s and a smooth surface. And it can be used to make HEMT devices. On the basisof this material structure device process such as mesa etch, Ohmic contact, andSchottkey gate are made. The conditions to etch to the AlGaSb buffer layer are studiedof. Ni/Au/Ni/Au alloyed Ohmic contact was made and a contact resistance of0.312Ω mm was got. Ti/Au Schottkey gate contact was made after InAs cap layer removed by1M citric acid:H2O2, and a Schottkey barrier of0.74eV was got.