Vacancy controlled interdiffusion of the group V sublattice in strained InGaAs/InGaAsP quantum wells

Abstract

In this letter we present the results of a photoluminescence study of the interdiffusion of arsenic and phosphorous in the In_0.66Ga_0.33As/In_0.66Ga_0.33As_0.7P_0.3 system over the temperature range 950–600 °C. We have shown that the diffusion is Fickian with no dependence of the diffusion coefficient on the substrate doping type or etch pit density. For both tin‐ and sulfur‐doped substrates the diffusion can be described by a diffusion coefficient D, which is given by D=D₀ exp(−E_A/kT), where D₀=23 cm²/s and E_A=3.7 eV for temperatures greater than 675 °C. This activation energy is the same as that determined for the group III interdiffusion in In_0.2Ga_0.8As/GaAs. Below this temperature a lower activation energy process takes over with D₀=5×10⁻¹⁰ cm²/s and E_A=1.7 eV.