Manufacturable MBE growth process for Sb-based photodetector materials on large diameter substrates

Antimony-based photodetector materials have attracted considerable interest for their potential and demonstrated performance in infrared detection and imaging applications. Mid-wavelength infrared detector has been demonstrated using bulk InAsSb/AlAsSb-based nBn structures. Heterostructures based on InAs/Ga(In)Sb strained layer superlattices create a type-II band alignment that can be tailored to cover a wide range of the mid- and long-wavelength infrared absorption bands by varying the thickness and composition of the constituent materials. Through careful design, these Sb-based detectors can realize desirable features such as higher operating temperature, better uniformity, suppression of Auger recombination, reduction of tunneling currents, and higher quantum efficiency. The manufacturing challenge of these structures is the reproducible growth of high-quality Sb-based epiwafers due to their complex designs including large numbers of alternating thin layers and mixed group-V elements. In this paper, we discuss the manufacturability of such epiwafers on 3" and 4" diameter GaSb substrates by molecular beam epitaxy using multi-wafer production tools. Various techniques were used to characterize the material properties of these wafers, including high-resolution x-ray diffraction, low-temperature photoluminescence, Nomarski optical microscopy, and atomic force microscopy.