Type-II superlattice structure based on indium arsenide and preparation method

The invention discloses a type-II superlattice structure based on indium arsenide and a preparation method. The type-II superlattice structure based on indium arsenide comprises an InAs layer, a GaAs layer, a GaAsxSb1-xlayer and a GaAs layer from bottom to top, and is characterized in that: (1) an original GaSb substrate is replaced with an InAs substrate, so that the growth temperature of superlattices is substantially increased, and the increasement of the growth temperature is conductive to increasing a diffusion length of surface atoms, thereby being more conductive to the two-dimensional growth of materials and the reduction of material defect density; (2) an As valve is always in an open state during the whole growth process of type-II superlattices, so that a GaAsSb ternary compound is formed due to the outflow of partial As when growing a GaSb layer, growth temperature of the layers tends to be uniform due to the existence of the common element As in the layers, and the counterdiffusion at interfaces is reduced; (3) variation of thickness of the InAs layer has small influence on mismatching of the InAs-based type-II superlattices, the growth difficulty of long waves materials, particularly extremely-long-wave materials, is extremely reduced, and the performance and quality of the materials can be more easily improved.