A new method to analyze multiexponential transients for deep-level transient spectroscopy

Abstract

A new technique is introduced to analyze digitally recorded capacitive transients in order to determine the properties of deep states. Using a nonlinear double exponential fitting routine, it is shown that a two-trap model can be applied to the transient data. We determine the individual trap concentrations and produce two Arrhenius plots. The latter yields the thermal activation energies and capture cross sections of closely spaced traps. The excellent agreement between the new technique and the standard rate window technique is shown via a simulation deep-level transient spectroscopy spectrum. The new method is applied to Se-doped AlxGa1−xAs (x=0.19 and 0.27) grown by metal-organic chemical vapor deposition. The measured results for all deep states including the DX centers agree well with the values published in the literature.