Silicon doping and impurity profiles in Ga0.47In0.53As and Al0.48In0.52As grown by molecular beam epitaxy

摘要

Silicon‐doped n‐type Ga0.47In0.53As and Al0.48In0.52As epitaxial layers lattice matched to InP substrates have been grown by molecular beam epitaxy. Doping levels up to 7×1018 cm-3 vary proportionally with the arrival rate of Si. For the same Si arrival rate, the carrier concentrations in both ternary epitaxial layers are identical. Mobility studies showed that the variations of electron mobility as a function of carrier concentration in Si‐doped Ga0.47In0.53As are in good agreement with the theoretically calculated results involving the alloy scattering mechanism at both 77 and 300 K. This alloy scattering mechanism is attributed to the defects induced at lower growth temperature. Doping profile measurements by the differential capacitance technique show that very abrupt changes in carrier concentration can be realized in Si‐doped Ga0.47In0.53As and Al0.48In0.52As and Sn‐doped Al0.48In0.52As. In the case of Sn‐doped Ga0.47In0.53As, the sharpness of the doping profile is limited by the surface segregation of Sn. Schottky barrier height on Ga0.47In0.53As was enhanced with the aid of a thin n‐type Al0.48In0.52As surface layer.