Dislocations and traps in p-InGaAs/GaAs lattice-mismatched heterostructures were studied by means of cross-sectional transmission electron microscopy and deep-level transient spectroscopy. The misfit and threading dislocations which were observed, by means of cross-sectional transmission electron microscopy in samples with various In mole fractions and various InGaAs layer thicknesses, all satisfied the Dodson-Tsao plastic flow critical layer thickness curve. By comparing the cross-sectional transmission electron microscopic and deep-level transient spectroscopic results, it was deduced that the threading dislocations in bulk layers introduced 3 hole trap levels (H1, H3, H5) with deep-level transient spectroscopic activation energies of 0.32, 0.40 and 0.88eV, respectively. There was also an electron trap level, E1, with a deep-level transient spectroscopic activation energy of 0.54eV. Misfit dislocations in the relaxed InGaAs/GaAs interface introduced a hole trap level, H4, with a deep-level transient spectroscopic activation energy of 0.67 to 0.73eV.

A.Y.Du, M.F.Li, T.C.Chong, K.L.Teo, W.S.Lau, Z.Zhang: Applied Physics Letters, 1996, 69[19], 2849-51