Studies on new low noise silicon radiation detector

In connection with a research project for developing room temperature energy dispersive detectors for X ray spectroscopy the possibility of integrating a signal amplifying transistor directly on the detector is studied. The idea is to integrate a normal FET (Field Effect Transistor) structure on high resistivity n-type semiconductor wafer with p-type layer on the other side of the bulk. This kind of structure acts as a detector when it is completely depleted from the p-side. The amplification of the transistor is based on the shape of the electric potential in the detector. First detectors based on this method were manufactured using MOS transistor technology. Results on transistor characteristics, detector depletion behavior and readout electronics are presented. The shape of the electric potential and charge carrier (concentration distribution of a detector utilizing JFET (Junction FET) technology was studied by simulation using the knowledge of the possible processing steps as parameters. The simulations suggested that detectors based on a FJET structure can be manufactured.