Dependence of electron mobility on gate voltage sweeping width and deposition temperature in MOSFETs with HfO2/ Al2O3/ InGaAs gate stacks

作者：Ohsawa Kazuto^*; Netsu Seiko; Kise Nobukazu; Noguchi Shinji; Miyamoto Yasuyuki^*

来源：Japanese Journal of Applied Physics, 2017, 56(4): 04CG05.

DOI：10.7567/JJAP.56.04CG05

In this study, we fabricated MOSFETs with Al2O3/ InGaAs or HfO2/ Al2O3/ InGaAs gate stacks. The surface was subjected to nitrogen plasma and trimethylaluminum cleaning prior to low-temperature atomic layer deposition. Electron mobility was extracted using the capacitance-gate voltage (C-VG) and drain current-gate voltage (ID-VG) characteristics. We determined that the mobility decreased when the gate voltage sweeping width increased during C-VG and ID-VG measurements. In addition, we determined that the lowering of the deposition temperature to 120 degrees C improved the mobility of MOSFETs with HfO2/Al2O3/ InGaAs gate stacks as compared with that corresponding to deposition at 300 degrees C. Furthermore, HfO2/ Al2O3/ InGaAs gate stacks with various Al2O3 thicknesses were fabricated. When the number of Al2O3 deposition cycles was more than 4, the mobility of MOSFETs with HfO2/ Al2O3/ InGaAs gate stacks improved, reaching the value of the Al2O3/InGaAs gate stack.

• 出版日期2017-4