Experimental method for determining the supply current of a PMOS power transistor for use as a RADFET dosimeter

Radiation Sensitive MOSFETs (RADFETs) have been commonly used as ionizing radiation dosimeters. The threshold voltage variation is the main transistor parameter used for radiation dosimetry, as this voltage variation is directly related to total dose and it can be easily determined by using simple measurement and biasing circuits. In this work it is presented a novel experimental method to determine the optimal drain-source current value to be supplied to a p-type MOSFET used in a traditional RADFET configuration (diode connected transistor) for monitoring of the accumulated X- and gamma-radiation dose. Experimental results from irradiations with 60Co gamma-rays and comparison measurements with semiconductor analyzer indicate that lower supply current values result in more precise dose measurement results.