High-Quality InSb Grown on Semi-Insulting GaAs Substrates by Metalorganic Chemical Vapor Deposition for Hall Sensor Application
Xin Li1,2, Yu Zhao2, Min Xiong2, Qi-Hua Wu2, Yan Teng1,2, Xiu-Jun Hao2,3, Yong Huang1,2**, Shuang-Yuan Hu4, Xin Zhu4
1School of Nano Technology and Nano Bionics, University of Science and Technology of China, Hefei 230026 2Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123 3School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210 4Suzhou Matrix Opto Co. Ltd, Suzhou 215614
Abstract:High-quality InSb epilayers are grown on semi-insulting GaAs substrates by metalorganic chemical vapor deposition using an indium pre-deposition technique. The influence of V/III ratio and indium pre-deposition time on the surface morphology, crystalline quality and electrical properties of the InSb epilayer is systematically investigated using Nomarski microscopy, atomic force microscopy, high-resolution x-ray diffraction, Hall measurement and contactless sheet resistance measurement. It is found that a 2-μm-thick InSb epilayer grown at 450$^{\circ}\!$C with a V/III ratio of 5 and an indium pre-deposition time of 2.5 s exhibits the optimum material quality, with a root-mean-square surface roughness of only 1.2 nm, an XRD rocking curve with full width at half maximum of 358 arcsec and a room-temperature electron mobility of $4.6\times10^{4}$ cm$^{2}$/V$\cdot$s. These values are comparable with those grown by molecular beam epitaxy. Hall sensors are fabricated utilizing a 600-nm-thick InSb epilayer. The output Hall voltages of these sensors exceed 10 mV with the input voltage of 1 V at 9.3 mT and the electron mobility of $3.2\times10^{4}$ cm$^{2}$/V$\cdot$s is determined, which indicates a strong potential for Hall applications.