Alpha-particle sensitive test SRAMs

• Published in: IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (USA) Vol. 37; no. 6; pp. 1849 - 1854
• Main Authors: Buehler, M.G., Blaes, B.R.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Legacy CDMS IEEE 01.12.1990
• Subjects: 440101 - Radiation Instrumentation- General Detectors or Monitors & Radiometric Instruments; 440200 - Radiation Effects on Instrument Components, Instruments, or Electronic Systems; ALPHA PARTICLES; CHARGED PARTICLES; CMOS technology; DESIGN; ELECTRIC CHARGES; ELECTRONIC CIRCUITS; Electronics And Electrical Engineering; INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; Ion sources; Laboratories; MEASURING INSTRUMENTS; MONITORS; MOSFETs; Optical pulses; PERFORMANCE TESTING; PHYSICAL RADIATION EFFECTS; Propulsion; RADIATION EFFECTS; RADIATION MONITORS; Random access memory; SENSITIVITY; TESTING; Voltage control
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/23.101200

A bench-level test is being developed to evaluate memory-cell upsets in a test SRAM designed with a cell offset voltage. This offset voltage controls the critical charge needed to upset the cell. The effect is demonstrated using a specially designed 2- mu m n-well CMOS 4-kb test SRAM and a Po-208 5.1-MeV 0.61-LET alpha-particle source. This test SRAM has been made sensitive to alpha particles through the use of a cell offset voltage, and this has allowed a bench-level characterization in a laboratory setting. The experimental data are linked to a alpha-particle interaction physics and to SPICE circuit simulations through the alpha-particle collection depth. The collection depth is determined by two methods and found to be about 7 mu m. In addition, alpha particles that struck outside the bloated drain were able to flip the SRAM cells. This lateral charge collection was observed to be more than 6 mu m.< >