Electroreflectance study of InGaAsP quaternary alloys lattice matched to InP

Abstract

Characterization of InGaAsP lattice matched to InP has been performed by electroreflectance measurement. For the measurement, In <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</inf> Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> As <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</inf> P <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-y</inf> alloys ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0 &lt; y &lt; 1</tex> ) were grown on InP substrates using a vertical LPE furnace and Schottky-barrier diodes were fabricated on them. Analysis of the electroreflectance (ER) spectra taken at the low-field condition has enabled us to determine precisely the energies of the fundamental band edge and the corresponding spin-orbit split-off edge of InGaAsP alloys lattice-matched to InP over the whole composition range. The compositional variations of the band edge, its temperature coefficient near room temperature and the spin-orbit splitting of the valence band in the InGaAsP quaternary alloy system are reported.