Characterization methodology for pseudomorphic high electron mobility transistors using surface photovoltage spectroscopy

Pseudomorphic high electron mobility transistor structures have been charac terized using surface photovoltage spectroscopy and numerical simulations. According to the effect of the electric fields in different regions of the device on the surface photovoltage spectra, a simple empirical model that c orrelates the spectral parameters and electrical parameters of the structur e has been developed. The spectra and their analysis are shown to provide v alues for the electrical parameters of the structure. The sensitivity of th e technique to the device electrical parameters is shown by three different examples. In these examples, the differences in doping level and surface c harge have been monitored as well as the nonuniformity of doping level acro ss the wafer. (C) 2000 American Institute of Physics. [S0021-8979(00)08324- 9].