Rapid computer-controlled capacitance transient characterization of deep-level centers

A computer-based deep-level capacitance transient spectrometer is described which was designed and constructed as a result of the inadequacy of present commercially available deep-level transient spectrometers. Deep-level activation energies and trap concentrations are here obtained in a single-temperature scan. Unlike conventional systems, which “contour” predetermined emission rates by viewing a rate window, giving only one point per level, thermal emission rates are here directly determined. This retains more information and reduces the redundancy of conventional methods by obtaining all information necessary to construct an Arrhenius plot in a single-temperature ramp. The method requires fewer computer calculations compared with systems using Fast Fourier Analysis, and displays improved signal-to-noise ratios. Data is displayed in the form of an Arrhenius plot for level depth and capture cross section assessment, and a ΔC versus temperature graph provides information on trap concentrations. The time required to determine such data is reduced to less than one sixth of that needed using conventional methods, and with the use of a multiplexing system two samples may be analyzed simultaneously, also in a single-temperature scan, thus reducing data aquisition times even further.