Simulation and process flow of radiation sensors based on chalcogenide glasses for in situ measurement capability

In this work we present data about electronic devices based on a planar structure; inert electrode/nanophase chalcogenide glass/inert electrode in close proximity with a source of silver (Ag) oriented laterally over the chalcogenide glass film. The conductivity of the devices changes with radiation and it can be measured by contacting the two inert electrodes. Spacing of the electrodes was chosen after an in-depth investigation into the electric field (E-field) and E-field energy displacement simulations with the aid of COMSOL multi-physics software. Simulations have been used to enlighten a specific device structure to perform in situ measurements. Bias voltages, inert electrode material and thickness of the films were used as standards for all different types of simulations while only varying the spacing and the geometries to affect the E-fields. It has been established from the experimental results that a 1 V bias is the most appropriate for the device performance and this is the voltage used in the simulations. The key motivation for this research is to find appropriate dimensions and geometry, which do not cause a change in conduction as a direct result of the applied E-field, but rather effectively contribute to the establishment of only the radiation induced change of the device conductivity. The process flow for the device fabrication is described and data from the device performance are presented as well. The radiation induced Ag doping is mapped in the device volume using electron dispersion X-ray spectroscopy (EDS).