Title :
Radiation effects in five volt and advanced lower voltage DRAMs
Author :
Shaw, D.C. ; Swift, G.M. ; Padgett, D.J. ; Johnston, A.H.
Author_Institution :
Jet Propulsion Lab., California Inst. of Technol., Pasadena, CA, USA
Abstract :
This work examines the effects of ionizing radiation on highly scaled DRAMs. Several 4 Mb and 16 Mb DRAMs with 5.0, 3.6, and 3.3 volt memory arrays are compared. A novel approach using memory cell retention time is introduced and applied that allows insight into the effects of radiation on individual devices within a DRAM array. Data from this new application of retention time exhibits significant changes due to ionizing radiation, even at low levels where other device parameters do not change significantly. The parameter, /spl tau/ (50%), is introduced that helps classify DRAM radiation response. Data are presented showing that there are two different damage mechanisms that affect DRAM radiation response. Finally, a relationship between threshold voltage and retention time is shown for several DRAMs.<>
Keywords :
DRAM chips; failure analysis; integrated circuit reliability; integrated circuit testing; radiation effects; 16 Mbit; 3 to 5 V; 4 Mbit; DRAM radiation response; damage mechanisms; data retention time test; dynamic RAM; highly scaled DRAM; ionizing radiation; lower voltage DRAMs; memory arrays; memory cell retention time; radiation effects; threshold voltage; Circuits; History; Ionizing radiation; Laboratories; Propulsion; Radiation effects; Random access memory; Space technology; Space vehicles; Threshold voltage;
Journal_Title :
Nuclear Science, IEEE Transactions on
