Speaker
Description
Bulk and surface defects in semiconductor devices are known to cause negative effects, including increased leakage current and increased charge trapping. Radiation from both high energy photons and particles (typically neutrons or protons) increases these negative effects, and will eventually render the device unusable. Previous studies have been performed demonstrating microwave annealing as an effective technique for low-temperature activation of dopants and reduction of interface defects in some limited applications, but have not considered using microwave annealing to enhance silicon radiation sensors, or microwave annealing of radiation induced defects.
In this study, we investigate the impact of microwave annealing on defects in devices fabricated with sensor-grade float-zone silicon, evaluating their behavior both before and after irradiation. A set of MOS capacitors, gate-controlled diodes, and PIN diodes were irradiated at the Gamma Irradiation Facility (GIF), and a set of silicon photomultiplier sensors (SiPMs) and PIN diodes were irradiated at the McClellan Nuclear Research Center. Several parameters pertaining to surface and bulk defects are measured for these devices, such as the surface current density, oxide charge density, carrier lifetime, and dark count rate in the SiPMs. Following microwave annealing, improvement in some of these parameters are observed both for unirradiated and irradiated devices.