A floating gate mosfet dosimeter requiring no external bias supply
IEEE Transactions on Nuclear Science , Volume 45 - Issue 3 PART 3 p. 1470- 1474
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.