An Enhanced Sensitivity Operation Mode for Floating Gate Dosimeters

A new method for enhancing the sensitivity of the Floating Gate DOSimeter (FGDOS) has been investigated. By increasing the electric field in the silicon dioxide, it is possible to improve the fractional yield of collection of the electron–hole pairs, thus to increase the device’s sensitivity. In particular, a sensitivity enhancement implies a proportional improvement of the sensor’s dose resolution. Such an amelioration would dramatically improve the dosimeter’s performance in low dose rate environments, especially when only short time windows are available for measurements. Moreover, a higher electric field in the floating gate oxide makes for an improved sensitivity degradation rate throughout the device’s radiation lifetime. Results, both from analog and digital test chips, are presented, proving the effectiveness of the enhancement and its effect on the FGDOS’ sensitivity degradation rate. Finally, both aspects are discussed and explained from a theoretical point of view.