Research on wet etching techniques for very long-wavelength InAs/GaSb superlattices

Manufacturing high-quality very long-wavelength infrared detectors (VLWIR) on GaSb substrate is significant for advancing the superlattices application in the field of infrared detection. In this study, superlattices with excellent surface and crystal quality were obtained. Based on it, we delved into the wet chemical etching fabrication for very long-wavelength InAs/GaSb superlattices. The impact of varying concentrations of different components on surface etching results along the growth direction was examined through univariate experiments. The analysis revealed that the concentration and ratios of phosphoric acid and hydrogen peroxide notably dictated both the etching rate and surface roughness. The surface chemistry of GaSb and InAs bulk materials treated with various etching solution components was investigated using X-ray photoelectron spectroscopy (XPS). The objective of this study is to provide a comprehensive understanding of the effects caused by different components in wet etching, thereby enhancing the understanding of the wet etching process for InAs/GaSb materials.