Low temperature growth and physical properties of InAs thin films grown on Si, GaAs and In0.53Ga0.47As template

Abstract

Integration of III-V semiconductors on a Si platform is interesting for both nanoelectronic and optoelectronic devices. Among the different challenges, the formation of low resistive contacts remains essential. In this paper, the growth by metalorganic chemical vapor deposition of thin InAs film as intermediate layer between the III-V materials and the metal has been studied on different templates: Si(100), GaAs/Si(100) and In0.53Ga0.47As/InP/GaAs/Si(100). We have shown that the formation of a continuous layer with low surface roughness is obtained at a growth temperature below 500°C with a two steps growth mode. The influence of the substrate on which the InAs is deposited, is investigated through morphological and structural properties. We observed an evolution of the InAs surface morphology versus the templates used. The surface roughness value obtained is 2.5nm, 0.9nm and 2nm respectively for a 30nm InAs layer grown on Si(100), GaAs/Si(100) and In0.53Ga0.47As/InP/GaAs/Si(100). Structural characterization shows that InAs crystal quality is better when GaAs/Si(100) are used as templates compared to growth on Si(100) and In0.53Ga0.47As/InP/GaAs/Si(100). The n-type doping using silicon as impurity allows a doping level of 5×1019cm−3 for all InAs layers, which favors the formation of low resistance contacts. Moreover we measured aa minimum resistivity of 6×10−4Ω·cm−1 for InAs on Si(100) and 10−4Ω·cm−1 for InAs on GaAs/Si(100) and In0.53Ga0.47As/InP/GaAs/Si(100).