Low frequency oscillations in undoped GaAs as a probe to deep level parameters

Low frequency oscillations that produce 1/f noise in GaAs FETS are characterized using a new method. The low frequency current oscillations of undoped LEC GaAs substrates are used to determine deep level energies, cross sections and concentrations. The frequency is seen to vary almost four orders of magnitude in a 50°K temperature range. Plotting the temperature dependence of each frequency component in an Arrhenius plot gives activation energies and cross-sections corresponding to the deep levels responsible for the oscillations. This technique allows the determination of trap parameters as a function of electric field at values much less than the critical field for intervalley transfer in GaAs.