Interface supersaturation dependence of step velocity in liquid-phase epitaxy of InP

摘要

By employing microchannel epitaxy (MCE), it became possible to reduce the dislocation density in liquid-phase epitaxy (LPE) of InP, so that steps supplied from only one screw dislocation can cover whole surface of MCE island. This enabled us to measure interstep disttance by AFM and to calcualte interface supersaturatione even in metallic solution with the help of the formula given byCabrera and Levine. From the interstep distance, the step velocity was calculated by employing the macroscoic vertical grwoth velocity. It was found that the step velocity increases linearly with the increase of the interface supersaturation, and the slope of the curve, which gives a step kinetic coefficient of the grwoth, increases with the increase of the groth temperature. From the Arrhenius plot of the kinetic coefficient of the grwoth, increases with the increase of the grwoth temepruatrue. From the Arrhenius plot of the kinetic coeficient, the activation energy of step advance was found as E=32.8 kJ/mol. A critical value of the interface supersaturation σ_c probably means that step advance is stopped by the impurity pinning effect.