Continuous Growth of High Purity InP/InGaAs on InP Substrate by Vapor Phase Epitaxy

Growth conditions and crystal properties for InP and InGaAs layers successively grown by vapor phase epitaxy are described. After InGaAs lattice-matched to a (100) InP substrate is deposited, InP is successively grown by using a sliding substrate holder and changing the growth temperature profile. Optimum growth conditions to reduce etch pit density and unwanted interface states at the heterointerface are discussed. Planar InP/InGaAs photodiodes fabricated from grown crystals have dark current density of 2.4×10 -5 A/cm 2 at -40 V. Carrier densities for InP and InGaAs are about 3.5×10 15 cm -3 , which is suitable for photodiodes with small capacitance.