MOSFET dosimeters incorporating an electrically floating polysilicon gate have been fabricated in a commercial CMOS technology. Charge is placed on the floating gate by tunnelling from a small overlapping injector gate. Subsequent irradiation partially discharges the floating gate, producing a change in threshold voltage which can be used to infer the absorbed dose. No external power source is required during this sensing period. Sensitivities up to 70 mVGy-1 (0. 7 mV/rad) have been obtained for temperature-compensated matched-pair dosimeters under 60Co gamma irradiation.

Additional Metadata
Journal IEEE Transactions on Nuclear Science
Tarr, N.G. (1998). A floating gate mosfet dosimeter requiring no external bias supply. IEEE Transactions on Nuclear Science, 45(3 PART 3), 1470–1474.