Capacitance-Voltage-Method Carrier Concentration Depth Profiles in Liquid-Encapsulated-Czochralski-Technique Grown GaAs Wafers from Near-Stoichiometric and Extremely-Composition Melts

Abstract

ABSTRACTIt was observed that carrier concentration depth profiles under 200μm-diameter gold Schottky electrodes of deeply Si-implanted electrically active layers on undoped semi-insulating GaAs wafers depend on melt composition of liquid-glass encapsulation Czochralski technique (LEC) growth, Fourier-transformed infrared (FT-IR) measurement carbon content of LEC growth, and consecutive cooling thermal cycle of LEC growth. In the range of this experiment, for head position of boules and 2.5 × 10exp.12/cm2 Si dosage, peak carrier concentrations of As-rich melt LEC growth (initial: [As]/([As]+[Ga])≃0.526) were comparable to or slightly higher than those of near-stoichiometric melt LEC growth. For tail position and 3 × 10exp.12/cm2 Si dosage, a peak carrier concentration of a father As-rich melt LEC-growth was clearly higher than that of Ga-rich melt LEC-growth. LEC-grown melt composition effect depended on consecutive cooling thermal cycle. For peak carrier concentration dispersion of head position, there was anticorrelation between carbon content of FT-IR measurement and peak carrier concentration dispersion.