Effect of electric field on silicon photomultipliers for scintillation detector applications

Abstract

In this dissertation, I investigate the degree to which the electric field developed within the depletion region can influence the DCR and PDE quantitatively. More importantly, I demonstrate the photon-number resolving capability of an SiPM ($R_{SiPM}$) under an arbitrary light exposure with respect to the electric field strength to highlight the significance of well structures for designing an SiPM for a target scintillator detector application. To demonstrate the influence of the electric field on SiPM characteristics, SiPMs with three different p-well implantation conditions were selected to produce three different electric field profiles in descending order with the identical device layouts and under the identical fabrication environments. Measurements on the VBD, gain, DCR, PDE, and correlated noise were accordingly obtained from the fabricated samples. Based on the measured device parameters, the $R_{SiPM}$ of each sample was calculated to demonstrate how the electric field in the depletion region could quantitatively influence the SiPM performance. Ultimately, the intention of this research is to provide a guideline for obtaining appropriate SiPM parameters for target applications under given fabrication conditions.