Analysis of HEMT Time-Evolution Characteristics

A novel transient measurement of the time-evolution of drain characteristics is analyzed to separate thermal and trapping dispersions. The procedure extracts isothermal characteristics from the measured data and parameterizes thermal dispersion. A significant dispersion effect in the isothermal characteristics is then linked to leakage currents that are related to drain potential. The effect of impact ionization is also evident in the data. This analysis provides information necessary to formulate bias- and rate-dependent models of HEMTs.