Enhanced Incorporation of P into Tensile-Strained GaAs1-yPy Layers Grown by Metal-Organic Vapor Phase Epitaxy at Very Low Temperatures

摘要

Metal-organic vapor phase epitaxy (MOVPE) of tensile-strained GaAs1-yPy layers on GaAs substrates was carried out over the temperature range from 380 to 650 degrees C. The P content in the GaAs1-yPy epitaxial layers initially decreases with decreasing growth temperature from 550 to 650 degrees C, while then exhibiting an increase with decreasing growth temperature from 550 to 380 degrees C. Thermodynamic calculations indicate that P incorporation is far from thermodynamic equilibrium at all growth temperatures. Related surface kinetics for the anion incorporation competition are discussed and it is suggested that the P incorporation is assisted by the increased P surface coverage at low growth temperatures. GaAs1-yPy tensile strained layers with layer thickness exceeding the critical thickness exhibit an early stage of strain relaxation by the formation of cracks rather than misfit dislocations. (c) The Author(s) 2016. Published by ECS. All rights reserved.