Dislocation-related deep levels in GaInAs layers which had been grown onto GaAs substrates by means of molecular beam epitaxy were investigated. Essentially unstrained Ga1-xInxAs layers, where x was 0.1, 0.2 or 0.3, were obtained by choosing the In composition of linearly graded Ga1-xInxAs buffers. Two electron traps, E2 and E3, whose activation energies scaled well with the energy gap, were found. Unlike E2, E3 exhibited a logarithmic dependence of the deep-level transient spectroscopy amplitude upon the filling pulse width and an increase in concentration as the buffer/GaInAs interface was approached. Together with the observation that, in compressively strained Ga0.8In0.2As, the E3-related concentration was definitely higher than that of essentially unstrained Ga0.8In0.2As, indicated that this trap probably originated from extended defects such as threading dislocations.

Deep levels in virtually unstrained InGaAs layers deposited on GaAs D.Pal, E.Gombia, R.Mosca, A.Bosacchi, S.Franchi: Journal of Applied Physics, 1998, 84[5], 2965-7