Angular Dependence of SOI Transistor Response to Heavy Ion Irradiation

Experimental results showing angular dependence for charge collection in SOI transistors under heavy ion irradiation are presented. Geant4 and Synopsys Sentaurus simulations are performed to analyze these results in terms of direct ionization effects. The influence of the beam direction in relation to that of the transistor's channel on the transistor's response is underlined. Depending on the considered beam direction, deviation from the inverse-cosine law is shown to vary from 0% to 30%. These differences seem to be independent of the ion energy. However, the use of different ion species may hide this possible effect.