A Semifloating Gate Controlled Camel Diode Radiation Dosimeter

A camel diode (CD) gamma-ray dosimeter with dual semifloating gates (SFGs) is presented. The SFG diode performs the function of collecting holes accumulated in the potential hump of CD, and hence controls the barrier height. With the silicon depletion instead of oxide as sensitive area, the sensitivity of the dosimeter is enhanced, while the volume is reduced compared with the conventional dosimeters. Moreover, the dosimeter requires only 2 V bias to reset within 1 ms. The numerical simulation has been carried out with Sentaurus TCAD. As a result, a linear dependence of threshold voltage on absorbed dose of the gamma rays was obtained with a sensitivity of 143 mV/Gy. Due to its high sensitivity, low power, and convenient resetting operation, the design is highly suitable for radiotherapy applications.