Evaluation of surface passivation layers for bulk lifetime estimation of high resistivity silicon for radiation detectors

With the aim to identify an appropriate low-temperature surface passivation process that could be used for bulk lifetime estimation of high resistivity (HR) (>1 kOmega-cm) silicon for radiation detectors, different candidate passivating layers were evaluated on n-type and p-type standard Czochralski (CZ), HR magnetic Czochralski (MCZ) and HR float zone (FZ)) substrates. Minority carrier lifetime measurements were performed by means of a microwave PhotoConductance Decay single point setup. The results show that SiNx PECVD layers deposited at 200degC may be used to evaluate the impact of different processing steps and treatments on the substrate characteristics for radiation detectors.