Re-usable Metal Oxide Semiconductor sensors in a radiation dosimeter.

J. LIPOVETZKY , E. G. REDIN , M. MAESTRI , A. FAIGÓN

Montevideo, Uruguay

Congreso; 5 Congreso Iberoamericano de Sensores; 2006

Metal Oxide Semiconductor (MOS) dosimeters are p-channel transistors used to sense absorbed doses of ionizing radiation. The response saturates after receiving a high dose, limiting the life  of the sensor and requiring its periodic replacement in a dosimeter system. In this work, a new method is presented to restore the sensor to an initial state after being irradiated, allowing its reuse and improving the dose  measurement accuracy. The method consists on restoring, after irradiation, the threshold voltage to an initial value by means of a Fowler Nordheim tunnel injection. A  high repeatability in the  dosimeters responses is achieved by saturating, before the first use, the interface states density with electrical and radiation stress.