Si‐Doping of Low‐Temperature‐Grown GaAs Heterostructures on (100) and (111)A GaAs Substrates

Abstract

Utilizing the amphoteric property of silicon impurity in GaAs (111)A for acceptor doping of low‐temperature‐grown (LTG‐) GaAs films and LTG‐GaAs‐based heterostructures for THz photoconductive applications is proposed and realized. The electronic properties of superlattice structures {LTG‐GaAs/GaAs:Si} grown by molecular beam epitaxy on (100) and (111)A GaAs substrates are experimentally investigated, where GaAs:Si are silicon‐doped GaAs layers grown at standard conditions. The use of GaAs substrates with surface orientation (111)A results in spatially indirect p‐type doping of LTG‐GaAs layers. In addition, the charge redistribution at the LTG‐GaAs/GaAs:Si interfaces, due to the presence of silicon atoms in GaAs:Si layers and antisite point defects in adjacent LTG‐GaAs layers, is also analyzed by means of band structure modeling.