Determination of semiconductor electrophysical parameters by microwave spectrum measurements of the coaxial probe impedance

We propose a method for determining semiconductors electrophysical characteristics (concentration and mobility of free charge carriers, conductivity) using measurements of the microwave impedance spectrum of a coaxial probe as a function of the applied constant voltage $U$. The parameters under study are found by solving the corresponding inverse problem using the developed theory of the near-field antenna. A computer program was created that searches for a solution by minimizing the multiparameter discrepancy function using the Nelder–Mead algorithm. The accuracy of the method is analyzed from simulation results in which the impedance is calculated via the obtained charge concentration profile $n(x, U)$ of the depleted layer in the vicinity of the metal-semiconductor contact. The possibility of diagnostics with micron lateral resolution is demonstrated.