Electron and hole traps in heavily compensated InGaAs/GaAs heterostructures

Abstract A variety of junction space charge techniques have been used to investigate an MBE grown In 0.083 Ga 0.917 As/GaAs, Al Schottky heterostructure, with the InGaAs layer above the critical thickness for this system. CV , IV and SIMS results suggest the top InGaAs layer to be heavily compensated and thus depleted of free carriers even under equilibrium conditions. Deep level transient spectroscopy measurements indicate an electron trap with an activation energy of 0.50 eV spatially located near the heterointerface as well as activation energies of 0.30 and 0.58 eV for defects in the bulk GaAs. Optical deep level transient spectroscopy was also used to investigate minority carrier defects in the InGaAs. It is argued that the depletion of the InGaAs layer gives junction space charge techniques a greater sensitivity for the determination of defect parameters located near the heterointerface, suggesting an improved approach for epilayer interface investigations.