DOSIMETER STRUCTURE BASED ON A MOS CAPACITOR WITH FLOATING GATE OF GERMANIUM NANOCRYSTALS AND A PROCESS FOR MANUFACTURING THE SAME

摘要

The invention relates to a MOS capacitor structure with floating gate of Ge nanocrystals immersed in HfOand to a process for manufacturing the same, the structure being used for monitoring the doses absorbed in spatial applications, radiation therapy, personal dosimetry and military applications. The claimed structure comprises three layers, namely: a control HfOlayer/a layer of Ge nanocrystals immersed in HfO/a HfOtunnel layer/a Si sublayer. The claimed process consists in depositing the three-layered structure on a Si wafer by magnetron sputtering, followed by a rapid thermal treatment in Ar in order to form the Ge nanocrystals immersed in HfOplaying the role of floating gate. The claimed structure has the properties of a dosimeter, with a sensitivity in the range of 1 mV/Gy at a dose of 200 Gy obtained from an α source of 241 Am.