Reconstruction of the charge collection probability in a semiconductor diode from collection efficiency measurements by the regularization method

Abstract

A new method is introduced to analyze the collection efficiency data that are obtained on a Schottky or p–n junction diode by irradiation with an electron beam with variable energy. The method aims at directly reconstructing the distribution φ(z) of the charge collection probability in the device, by inverting the integral transform that connects φ(z) to the measured collection efficiency profile. This inversion is generally an ill-posed problem, which, however, can be solved by the Tikhonov regularization method. This procedure is used to analyze published measurements obtained both on Si and GaAs diodes, and is shown to be particularly useful for characterizing nonideal devices.