摘要
GaSb is an attractive candidate for future high-performance Ⅲ-Ⅴ p-channel metal-oxide-semiconductor-field-effect-transistors(pMOSFETs)because of its high hole mobility.The effect of HCl 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 0.693 nm by using HCl:H_(2)O(1:3)solution.The Ni/Pt/Au ohmic contact exhibits an optimal specific contact resistivity of about 6.89×10^(-7)Ω·cm^(2) with a 60 s 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 6μm gate length GaSb pMOSFET,a maximum drain current of about 4.0 mA/mm,a drain current on-off(ION/IOFF)ratio of>10^(3),and a subthreshold swing of~250 mV/decade are achieved.Combined with the split C-V method,a peak hole mobility of about 160 cm^(2)/V·s is obtained for a 24μm gate length GaSb pMOSFET.
基金
Supported by the National Basic Research Program of China under Grant Nos 2011CBA00605,2010CB327501
the National Natural Science Foundation of China under Grant No 61106095
the National Science&Technology Major Project of China under Grant No 2011ZX02708-003
One Hundred Talents Program of Chinese Academy of Sciences,and the Scientific Research Foundation for the Returned Overseas Chinese Scholars,the Ministry of Education of China.
