Lattice parameter variation in doped GaAs substrates determined using high resolution photoluminescence spectroscopy

Abstract

Variations in the lattice parameters of commercially available undoped and Si-doped GaAs substrates have been studied using high resolution photoluminescence (PL) spectroscopy. The lattice parameter difference between high quality epitaxial layers of GaAs and the doped substrates upon which they are grown induces a biaxial strain in the epitaxial layer which can be detected with remarkable sensitivity using low temperature PL. The PL results show that a lattice mismatch as low as 0.0013% can cause significant and well-resolved changes in the features of donor (D°X) and acceptor (A°X) bound exciton spectra, which are consistent with results obtained from samples subjected to externally applied biaxial stress. In addition to studying a variety of low lattice mismatch GaAs/GaAs:Si heterostructures, the technique is also successfully employed in the case of more highly strained GaAs grown on an In0.004Ga0.996As substrate.

High-resolution photoluminescence measurement of the isotopic-mass dependence of the lattice parameter of silicon

“…8 This technique has, however, been previously used to measure lattice mismatches of order 10 −5 for epitaxial layers of undoped GaAs grown on doped GaAs substrates. 9 In this Brief Report, we provide corrected values of the lattice mismatch for the 28 Si/ nat Si samples, which were subjected to a numerical error in our preliminary study. 8 We also present results for the lattice mismatch of 30 Si/ nat Si determined using PL spectroscopy, and find it to be consistent with our results for 28 Si/ nat Si.…”