A New Method for Calculating Background Dopant Density from p-n Junction Capacitance-Voltage Measurements

A new method is presented for calculating the average background dopant density within the depletion layer of a planar diffused p-n junction using capacitance-voltage (C-V) measurements. The method has been successfully applied to specimens having a background dopant density as high as 10(18) cm(-3), and ideal data studies indicate that the method may be applicable to specimens having a background dopant density up to about 10(19) cm(-3). The average background dopant density is calculated by finding the Gaussian diffused layer as characterized by an effective surface dopant density, background dopant density, and junction depth which can best be fitted to all the C-V data. It is not necessary to know the actual surface dopant density. The method is illustrated by calculations on both real and idealized C-V data.