Direct measurement of the inter-diffusion in quantum wells enhanced by group V intermixing for InP- based structures

Group V inter-diffusion in InGaAsP/InP quantum wells (QW) has been studied using analytical electron microscopy in the temperature range of 600-850degC. The structure was grown by metalorganic chemical vapour deposition (MOCVD) and subsequently capped with a 100 nm thick layer of SiO
₂
, Si
₃
N
₄
or low temperature molecular beam epitaxy (MBE)-grown InP (LT-InP). Diffusion coefficients for the group V species were calculated from the width-concentration profiles and activation energies (E
_alpha
) together with diffusivity (D
₀
) were obtained from Arrhenius plots. Small as-grown compositional difference between quantum well and barriers (~6%) in group III prevents us from accurate analysis of ln-Ga interdiffusion.