High-Quality InSb Grown on Semi-Insulting GaAs Substrates by Metalorganic Chemical Vapor Deposition for Hall Sensor Application**Supported by the Hundred Talents Program of Chinese Academy of Sciences, the CAS Interdisciplinary Innovation Team, the National Natural Science Foundation of China under Grant Nos 61874179, 61804161 and 61605236, and the Key Frontier Scientific Research Program of Chinese Academy of Sciences under Grant No

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--thick InSb epilayer grown at 450°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 × 104 cm2/. 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 10mV with the input voltage of 1V at 9.3mT and the electron mobility of 3.2 × 104 cm2/ is determined, which indicates a strong potential for Hall applications.