The Growth of Al33GaSb/GaSb MQW on Silicon(100) substrate with Al66GaSb/AlSb SPS layer

Abstract

Sb-based material semiconductors have attracted for high-speed and low power electric devices. Silicon substrate has a lot of advantages including growth of large area and cost effectiveness comparing to GaSb substrate. However, the lattice mismatch of silicon and GaSb is ~13%. Thermal expansion effect and the growth of polar compound on a non-polar substrate are also obstacles [1]. The large lattice mismatch could make threading dislocations (TDs) and exacerbate GaSb crystal quality on silicon (100) substrate. Therefore, it is important to minimize threading dislocation in AlSb buffer layer [2]. AlGaSb/GaSb shore-period lattice (SPS) layer is used to overcome problem of large lattice mismatch. TDs would be bent to misfit dislocations (MDs) at the interface of SPS layer for strain release [3]. MDs could not affect to upper GaSb layer and would be dissipated at the interface of SPS layer. The surface of AlSb buffer layer was measured by AFM measurement. The root mean square (RMS) value of SPS layer is about 2nm. In addition, AlSb buffer layer will be measured by dark-field (DF) XTEM. GaSb/AlGaSb MQW PL spectra were obtained at room temperature and 10K with a fixed excitation power of 100mW. Emission peaks showed at 1761nm and 1623nm, respectively.