High-Quality 100 nm Thick InSb Films Grown on GaAs(001) Substrates with an InxAl1-xSb Continuously Graded Buffer Layer

In this paper, we report the growth of a high-quality 100 nm thick InSb layer on a (001) GaAs substrate for InSbbased high-speed electronic device applications. A continuously graded buffer (CGB) technique with InxAl1-xSb was used to grow high-quality InSb films on GaAs substrates. The CGB layer was grown by continuously changing the growth temperature and composition of the aluminum and indium during the growth of the buffer layer. Degradation of electrical properties, which normally accompany carrier-defect scattering in a heteroepitaxial layer, was minimized by using the CGB layer. The electrical properties of the InSb films were characterized by Hall measurements, and the electron mobility of the 100 nm-thick InSb film had the largest value, of 39 290 cm(2)/V.s, among reports of similar thickness. To investigate the relationship between electrical and structural properties, the 100 nm thick InSb film was characterized by energy-dispersive spectroscopy and transmission electron microscopy.