Controlling Macropores Etching in n-Si by Means of in-situ FFT Voltage- and Photoimpedance Spectroscopy

Abstract

In this work we use FFT-impedance spectroscopy for in-situ characterization of the macropores growth process in n-Si. The impedance is done in the applied voltage. Additionally a new type of photoimpedance is proposed that is calculated from the response of the etching current to the modulation of the backside illumination intensity. Both types of impedance offer a huge amount of data that can be used to interpret the state of the macropores at any instance in time. We consider that this information can be used, in a later stage, for in-situ control the pores growth process hence conceiving an automated etching system.