Research Review of InAs/GaSb Superlattice Mesa Etching Process

This paper reviews the research on InAs/GaSb superlattice mesa etching technology. The physicochemi-cal mechanism and parameter control of wet and dry etching are analyzed to elucidate the influence of process conditions on mesa morphology, so as to suppress the surface leakage current of long wave and very long wave superlattice with narrow band-gap. The results show that the uniform etching of the two components can be achieved with the appropriate proportion of etching solution in wet etching, without causing rough surface and serious undercut. In dry etching, Cl2-base and CH4-base mixed gas is used. By adjusting the type and proportion of etching gas, the balance between physical and chemical etching processes can be achieved to ensure the smoothness of the mesa sidewall and the perpendicularity of the dip angle. In addition, for superlattices of different components, different process parameters need to be selected to meet the synergistic etching of InAs and GaSb. Finally, the InAs/GaSb superlattice mesa