A neutron dosemeter based on a stack of two p-MOSFETs

The dosimetric characteristics of a new type of Metal-Oxide-Semiconductor field effect transistor (MOSFET), sensitive to both thermal and intermediate-fast neutrons were studied. The dosemeters were manufactured at LAAS-CNRS Laboratory in Toulouse, France. They consist of two identical MOSFETs, fabricated on the same silicon chip and showed excellent linearity for wide dose ranges. In order to be used as neutron dosemeters, a thin film of lithium fluoride was deposited on the surface of the MOS gate above the Cr layer. Their sensitivity to thermal neutrons, up to 1eV, is much higher than that of intermediate-fast neutrons.