METHOD AND APPARATUS FOR SINGLE-POLARITY CHARGE SENSING FOR SEMICONDUCTOR RADIATION DETECTORS DEPOSITED BY PHYSICAL VAPOR DEPOSITION TECHNIQUES

摘要

A system for improving the resolution of semiconductor based radiationdetectors deposited via physical vapor deposition(PVD) techniques (e.g. evaporation or sputtering such as amorphous Selenium,.alpha.-Se, Mercury Iodide, HgI2, Lead Oxide,PbO) which exhibit poor transport properties for either electrons or holes(depending on the type of the detector) due tosignificant carrier trapping. An additional electrical grid is establishedwithin the semiconductor between the top andbottom electrodes. The intermediate grid is biased at an appropriate potentialto eliminate the variation in the inducedcharge on photon interaction depth inside the detector volume. The proposedmethod improves the resolution and thesignal-to-noise ratio of the detector system and enables large-area pixelatedarray designs. The proposed hybrid readoutmethod also enables the design of low-noise readout electronics incomplementary metal-oxide semiconductor (CMOS)technologies for large area applications.