Antimonidation of ultrathin epitaxial aluminum nanofilms for metamorphic growth of Sb-based structures on GaAs substrates

Abstract

The narrow-bandgap Sb-based semiconductors find their potential in various kinds of device applications such as high-speed, low-power transistors and mid-infrared diode lasers. However, epitaxial growth on the substrates that are commercially available in large sizes (for example, GaAs and Si) faces the fundamental challenge of lattice mismatch. Different from the conventional metamorphic growth employing a thick buffer, we adopt the approach of transforming an ultrathin epitaxial aluminum (Al) nanofilm into epitaxial AlSb to serve as the template for growth of antimonide structures. It is found that the process named "antimonidation" plays a critical role in Sb-based metamorphic growth. Our experimental results provide practical usefulness for growing semiconductor devices on lattice-mismatched substrates without using thick metamorphic buffer layers. (C) 2020 The Japan Society of Applied Physics