An SEU tolerant memory cell derived from fundamental studies of SEU mechanisms in SRAM

Conference · Tue Dec 01 00:00:00 EST 1987 · IEEE Trans. Nucl. Sci.; (United States)

OSTI ID:7158856

Weaver, H T; Axness, C L; McBrayer, J D; Browning, J S; Fu, J S; Ochoa, A Jr; Koga, R

A new single event upset (SEU) hardening concept, an LRAM cell, is demonstrated theoretically and experimentally. Decoupling resistors in the LRAM are used only to protect against the short n-channel transient; longer persisting pulses are reduced in magnitude by a voltage divider, a basically new concept for SEU protection. In such a design, smaller resistors provide SEU tolerance, allowing higher performance, hardened memories. As basis for the LRAM idea, techniques were developed to measure time constants for ion induced voltage transients in conventional static random access memories, SRAM. Time constants of 0.8 and 6.3 nsec were measured for transients following strikes at the n- and p-channel drains, respectively - primary areas of SEU sensitivity. These data are the first transient time measurements on full memory chips and the large difference is fundamental to the LRAM concept. Test structures of the new design exhibit equivalent SEU tolerance with resistors 5-to-10 times smaller than currently used in SRAM. Our advanced transport-plus-circuit numerical simulations of the SEU process predicted this result and account for the LRAM experiments, as well as a variety of experiments on conventional SRAM.

• Research Organization: Sandia National Labs., Div. 1141, Albuquerque, NM (US)
• OSTI ID: 7158856
• Report Number(s): CONF-8707112-; TRN: 88-023540
• Journal Information: IEEE Trans. Nucl. Sci.; (United States), Vol. NS-34:6; Conference: Annual conference on nuclear and space radiation effects, Snowmass Village, CO, USA, 28 Jul 1987
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
FAULT TOLERANT COMPUTERS
MEMORY DEVICES
PERFORMANCE TESTING
RADIATION HARDENING
ELECTRICAL TRANSIENTS
ELECTRONIC CIRCUITS
EXPERIMENTAL DATA
IONS
MATHEMATICAL MODELS
NUMERICAL SOLUTION
RADIOSENSITIVITY
TECHNOLOGY ASSESSMENT
THEORETICAL DATA
CHARGED PARTICLES
COMPUTERS
DATA
DIGITAL COMPUTERS
HARDENING
INFORMATION
NUMERICAL DATA
PHYSICAL RADIATION EFFECTS
RADIATION EFFECTS
TESTING
TRANSIENTS
VOLTAGE DROP
420800* - Engineering- Electronic Circuits & Devices- (-1989)