Investigation on the InAs_(1-x)Sb_x epilayers growth on GaAs (001) substrate by molecular beam epitaxy

摘要

Undoped and Be-doped InAs_(1-x)Sb_x (0 ≤ x ≤ 0.71) epitaxial layers were successfully grown on lattice mismatched semi-insulating GaAs (001) substrate with 2° offcut towards <110>. The effect of the InAs buffer layer on the quality of the grown layers was investigated. Moreover, the influence of Sb/In flux ratio on the Sb fraction was examined. Furthermore, we have studied the defects distribution along the depth of the InAsSb epilayers. In addition, the p-type doping of the grown layers was explored. The InAsSb layers were assessed by X-ray diffraction, Nomarski microscopy, high resolution optical microscopy and Hall effect measurement. The InAs buffer layer was found to be beneficial for the growth of high quality InAsSb layers. The X-ray analysis revealed a full width at half maximum (FWHM) of 571 arcsec for InAs_(0.87)Sb_(0.13). It is worth noting here that the Hall concentration (mobility) as low (high) as 5 × 10~(16) cm~(-3) (25000 cm~2V~(-1)s~(-1)) at room temperature, has been acquired.