TID test for SDRAM based IEEM calibration system

Traditionally, to map out device sensitivity with submicrometric resolutions one uses a microbeam. Ion electron emission microscopy (IEEM) appears to be a promising new method for device characterization. An advanced implementation of this instrument is under development at the SIRAD irradiation facility of the Legnaro National Laboratory (LNL). In IEEM operations total integrated dose (TID) effects could be a potential problem and should be addressed before the final test. For this purpose a TID monitoring method, based on the measurement of the bit retention time, that is the time the information is retained in a memory cell without refresh, in synchronous dynamic RAM (SDRAM) commercial off the shelf (COTS) devices, is proposed. This paper presents the experimental setup and the results of a preliminary TID test with a /sup 60/Co gamma ray source on SDRAM COTS to test the method.