Radiation effects on commercial 4-kilobit NMOS memories

Conference · Wed Dec 01 04:00:00 EST 1976 · IEEE Trans. Nucl. Sci.; (United States)

OSTI ID:7256740

Myers, D K

The 4K NMOS dynamic RAM is one of the least radiation tolerant of modern semiconductor devices. Samples from seven manufacturers exhibit a uniformly high susceptibility to total dose with the failure threshold starting at 1700 rads (Si) and the parts completely dead by 3500 rads (Si). The entire circuit is dynamic including the peripheral circuitry with the sense amps detecting 200 millivolt signals. In the tested population, most failed for V/sub GT/ shifts. The design will tolerate <0.2 volt change. Test transistors on the die were measured confirming this conclusion. Circuit analysis and electrical autopsy indicate the X and Y decoders are stuck in ''1'' state causing failure. Most 4K NMOS devices are processed for optimization of electrical performance, commercial reliability and yield. These processes utilize chlorine oxides for stability, greater than or equal to 1000 A thick gate oxides for static discharge reliability, and silicon gate techniques for threshold and speed requirements. Changes in any of these processes affect at least one of the ''optimized'' performance criteria adversely so that the devices no longer meet commercial price/performance requirements. Increased complexity NMOS devices, such as 16K RAM's and microprocessors, utilize extensions of the existing NMOS technology and will also be very susceptible to ionizing radiation.

• Research Organization: Fairchild Camera and Instrument Corp., Palo Alto, CA
• OSTI ID: 7256740
• Conference Information: Journal Name: IEEE Trans. Nucl. Sci.; (United States) Journal Volume: NS-23:6
• Country of Publication: United States
• Language: English

Related Subjects

440200* -- Radiation Effects on Instrument Components
Instruments
or Electronic Systems
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ELECTRICAL PROPERTIES
ELECTRONIC CIRCUITS
MEMORY DEVICES
MOS TRANSISTORS
PHYSICAL PROPERTIES
PHYSICAL RADIATION EFFECTS
RADIATION EFFECTS
SEMICONDUCTOR DEVICES
SEMICONDUCTOR STORAGE DEVICES
TRANSISTORS