MEASUREMENT OF THE DOPANT DISTRIBUTION IN THIN EPITAXIAL SI AND GaAs STRUCTURES.

Doping profile is a very important technological parameter of almost all semiconductor devices. Its non-destructive measurement is generally based on the so-called C-V method. Instead of the direct C-V relationship, dC/dV vs. C gives, however, a more straightforward and accurate means of calculating the doping profile. The paper describes an instrument measuring directly dC/dV equals f(C) and discusses the practical limits of C, dC/dV and the area of the junction to be measured considering the sensitivity limit of the detector. The instrument is designed around three feedback loops for automatic compensations; one of them compensates for the losses varying during the measurement.