,GaSb p-Channel Metal-Oxide-Semiconductor Field-Effect Transistors with Ni/Pt/Au Source/Drain Ohmic

• 作 者: WU Li-Shu SUN Bin CHANG Hu-Dong ZHAO Wei XUE Bai-Qing ZHANG Xiong LIU Hong-Gang
• 机 构: Advanced Photonics Center, School of Electronic Science and Engineering, Southeast University, Nanji
• 出 处: 中国物理快报（英文版）
• 发表日期: 2012年12期

GaSb is an attractive candidate for future high-performance Ⅲ-Ⅴ p-channel metal-oxide-semiconductor-fieldeffect-transistors (pMOSFETs) because of its high hole mobility.The effect of HCI based-chemical cleaning on removing the non-self limiting and instable native oxide layer of GaSb to obtain a clean and smooth surface has been studied.It is observed that the rms roughness of a GaSb surface is significantly reduced from 2.731 nm to 0.693nm by using HCl:H2O (1:3) solution.The Ni/Pt/Au ohmic contact exhibits an optimal specific contact resistivity of about 6.89 × 10-7 Ω.cm2 with a 60s rapid thermal anneal (RTA) at 250℃.Based on the chemical cleaning and ohmic contact experimental results,inversion-channel enhancement GaSb pMOSFETs are demonstrated.For a 6 μm gate length GaSb pMOSFET,a maximum drain current of about 4.0 mA /mm,a drain current on-off (ION/IOFF) ratio of ＞103,and a subthreshold swing of ～250mV/decade are achieved.Combined with the split C-V method,a peak hole mobility of about 160cm2/V.s is obtained for a 24 μm gate length GaSb pMOSFET.