Dose and microdose measurement based on threshold shifts in MOSFET arrays in commercial SRAMs

A new dosimetry method using an array of MOS transistors is described for a measuring dose absorbed from ionizing radiation. The method uses direct measurement of the number of cells that change state as a function of applied-operating bias to a SRAM as a function of absorbed dose. Because the input and output of a SRAM are digital, the measurement of dose is easily accessible by a remote processing system. The devices show minimal response to total ionizing dose, but individual SRAM ceils show strong microdose effects. Index Terms--Microdose, oxide damage, single event effect, single-hard error (SHE), SRAM, stuck bit.