Angle resolved IBIC analysis of 4H-SiC Schottky diodes

We present a new experimental procedure based on the ion beam induced charge collection (IBIC) to characterise semiconductor detectors and devices. It consists in measuring the charge collection efficiency (g) as a function of the angle of incidence (a) of a strongly penetrating MeV ion beam focussed onto a partially depleted semiconductor detector. The unidimensional model based on the drift-diffusion model derived from the Shockley–Ramo–Gunn’s theorem gives the theoretical background to fit the g(a) curve and to estimate both the extension of the depletion layer, the dead layer thickness and the minority carrier diffusion length. To illustrate the analytical capability of this technique, a 2 MeV proton beam was focussed at different incident angles onto a 4H-SiC Schottky diode; the experimental results and the theoretical approach are presented and discussed.