Analysis of border and interfacial traps in ALD-Y2O3 and -Al2O3 on GaAs via electrical responses - A comparative study

作者：Chang T W; Lin K Y; Lin Y H; Young L B; Kwo J^*; Hong M^*

来源：Microelectronic Engineering, 2017, 178: 199-203.

DOI：10.1016/j.mee.2017.05.019

• Border trap
• Interfacial trap
• High-k dielectric
• GaAs
• ALD
• Y2O3

Y2O3 and Al2O3 were in-situ atomic layer deposited (ALD) on pristine GaAs(001)-4 x 6 reconstructed surfaces without surface pretreatments. We have studied the border and interfacial traps in both hetero-structures using the measured electrical responses. On the basis of frequency dispersion analysis of the capacitance-voltage (CV) characteristics, we conclude that Y2O3 has effectively passivated GaAs surface with a much lower interfacial trap density (D-it) than Al2O3 as the gate dielectric. The quasi-static CV and conductance measurements are in agreement with the above conclusion. We have demonstrated an excellent ALD-Y2O3/GaAs interface with low D-it's of (0.5-2) x 10(12) eV(-1) cm(-2) through the whole GaAs band gap without a mid-gap peak feature.

• 出版日期2017-6-25
• 单位清华大学