Metamorphic high electron mobility Te-doped AlInSb/GaInSb heterostructures on InP (001)

Abstract

This work reports on the Te δ-doping of high electron mobility AlInSb/GaInSb heterostructures grown by molecular beam epitaxy on InP(001) substrates with a metamorphic approach. The combination of atomic force microscopy and van der Pauw measurements is used to investigate and explain the influence of the buffer layers on the electron mobility and sheet density in the heterostructure. Furthermore, a significant increase in the electron sheet density is reached when the δ-doping plane is incorporated in a thin AlSb layer introduced in the barrier. This improvement is explained by the lower dopant activation energy in the AlSb layer. AlInSb/GaInSb heterostructures with an electron mobility of 18 000 cm2/V s and sheet density of 2.2×1012 cm−2 at room temperature are demonstrated.