Liquid phase epitaxy growth of high purity InP using rare earth dysprosium gettering

Abstract

Epitaxial layers of InP were grown on semi-insulating InP substrates by liquid phase epitaxy. The introduction of small amounts (4 × 10^-4 -1 × 10^-3 atomic fraction) of the rare earth dysprosium in the melt resulted in a substantial increase in electron mobility and a reduction in the electron concentration. The mobility increased from 2040 cm² V^-1 s^-1 (without dysprosium) to 4200 cm² V^-1 s^-1 (with dysprosium) at 300 K and from 2480 cm² V^-1 s^-1 to 19 250 cm² V^-1 s^-1 at 83 K. The carrier concentration accordingly decreased from 2.3 × 10¹⁷ to 4 × 10¹⁵ cm^-3 (300 K). The results of secondary-ion mass spectrometry and photoluminescence measurements indicate that reduction in the dominant impurity silicon by gettering is responsible for the improved properties.