GaAs Using Nondestructive Acousto-Electric Voltage Measurement

The amplitude and the transient time constant of the acoustoelectric voltage is measured as a function of temperature to determine the activation energy of deep levels in AI,Ga, -.As/GaAs grown by molecular-beam epitaxy. In comparison to other methods based on monitoring the capacitance transient, this method has several advantages. The technique is nondestructive, and because of the dependence of the polarity of the acoustoelectric voltage on the carrier type, it yields information about the charge of the transient carriers and the type of deep traps involved in the release or trapping of these carriers. It has also, in particular, large sensitivity in studying highresistivity materials.