Digital IBIC—new spectroscopic modalities for ion-beam-induced charge imaging

The first implementation of digital ion-beam-induced charge (IBIC) imaging is presented, which permits spectroscopic time-resolved IBIC imaging of charge transport in semiconductors. A digital IBIC system has been developed which uses a high-speed waveform digitiser to capture the pulse shapes produced by interactions of a 1 μm resolution scanning microbeam in semiconductor samples. Using a variety of digital pulse shape analysis algorithms, quantitative images of charge signal amplitude, charge carrier lifetime, mobility and trapping phenomena can be acquired in real-time, with a time resolution of <20 ns. We report data from the commissioning experiment which shows digital IBIC images of electron and hole transport in CdZnTe radiation detectors, obtained by lateral scanning of the ion beam between the cathode and anode. The room temperature electron drift mobility in CdZnTe was measured with a value of 1.1×103 cm2/Vs.