2020-2021 / 3107
MOSFET
Metal–Oxide–Semiconductor Field-Effect Transistor
8/31/16
5 V
GND ..
a
b
GND
Irradiation mode
Read-out mode
3.7 V
GND ..
Vgs
a
b
“Varying the voltage between the gate and body modulates the conductance of this layer and
makes it possible to control the current flow between drain and source. Conventionally, the
gate voltage necessary to allow conduction through the MOSFET is known as the
threshold
voltage.
When the MOSFET is exposed to ionizing radiation electron-hole pairs are formed in
the oxide insulation layer. The trapped positive charges cause a shift in the threshold voltage
proportional to the radiation dose deposited in the oxide layer.
The threshold voltage is
permanently changed by the absorbed dose classifying the MOSFET as an additive
dosimeter
“
Verellen et al. 2009