Observation of abnormal capacitance-frequency behavior in In0.12Ga0.88As/GaAs p-i-n superlattice grown at low temperature

Abstract

Capacitance-frequency measurement is used to study In0.12Ga0.88As/GaAs p-i-n superlattice, with superlattice layer grown at 300 degrees C by molecular-beam epitaxy. Three traps are observed, and their parameters are consistent with those obtained from deep-level transient spectroscopy. Among these three traps, the trap (E-a = 0.45 +/- 0.02 eV, sigma = 6 +/- 4x10(-17) cm(2)) shows an abnormal increase of capacitance with increasing frequency, similar to that observed from the 0.66 eV trap in low-temperature grown GaAs p-i-n structure, suggesting that it is created by the low-temperature growth and is a generation-recombination center. This result also shows that the capacitance-frequency measurement is effective in studying the generation-recombination centers. (C) 1999 American Institute of Physics. [S0003-6951(99)01434-5].