Deep Level Parameter Studies And Their Significance For Optically Controlled Solid State Switches

Deep level characterization studies have been made for various semiconductor materials (such as, as grown gallium arsenide (GaAs), silicon doped copper compensated gallium arsenide (GaAs.-Si:Cu)) of interest for photoconductive pulse power switches. Photo induced current transient spectroscopy(PICTS)techniquehasbeenusedformeasuring deep level parameters, such as activation energy, concentration and cross sections for electron and hole capture. Of particular interest is the information on different copper levels (Cu,, Cu,) and EL2 levels in silicon doped copper compensated GaAs switch, which has been shown to perform as optically controlled closing and opening switch. The analysis of the current transient is made by using the standard rate window method. Improvements in the PiCTS system has enabled us to detect CUA levels in our switch samples. The effect of processing parameters such as, diffusion temperature, time and, also the arsenic (As) overpressure during the diffusion of copper into the silicon doped GaAs is reported,