Title :
Implications of the spatial dependence of the single-event-upset threshold in SRAMs measured with a pulsed laser
Author :
Buchner, S. ; Langworthy, J.B. ; Stapor, W.J. ; Campbell, A.B. ; Rivet, S.
Author_Institution :
Naval Res. Lab., Washington, DC, USA
Abstract :
Pulsed laser light was used to measure single event upset (SEU) thresholds for a large number of memory cells in both CMOS and bipolar SRAMs. Results showed that small variations in intercell upset threshold could not explain the gradual rise in the curve of cross section versus linear energy transfer (LET). The memory cells exhibited greater intracell variations implying that the charge collection efficiency within a memory cell varies spatially and contributes substantially to the shape of the curve of cross section versus LET. The results also suggest that the pulsed laser can be used for hardness-assurance measurements on devices with sensitive areas larger than the diameter of the laser beam.<>
Keywords :
CMOS memory circuits; SRAM chips; bipolar memory circuits; errors; integrated circuit testing; measurement by laser beam; radiation effects; radiation hardening (electronics); CMOS SRAM; SEU thresholds measurement; SRAM testing; bipolar SRAM; charge collection efficiency; hardness-assurance measurements; intercell upset threshold; linear energy transfer; memory cells; pulsed laser; single-event-upset; spatial dependence; Circuits; Energy exchange; Error analysis; Laboratories; Optical pulses; Pulse measurements; Random access memory; Semiconductor lasers; Shape; Single event upset;
Journal_Title :
Nuclear Science, IEEE Transactions on