Fundamental criteria for the design of high-performance Josephson nondestructive readout random access memory cells and experimental confirmation

Journal Article · Sat Dec 01 04:00:00 EST 1979 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.325955· OSTI ID:5677776

Henkels, W H

Fundamental design criteria for Josephson nondestructive readout random access memory (NDRO RAM) cells are presented, within the context of an LSI array environment. Emphasis is placed upon principles which are relevant to high performance. The criteria are elucidated via a specific design which is simulated and then experimentally evaluated in a technology with a smallest critical dimension of 5 ..mu..m. The specific cell differs from previously tested Josephson NDRO cells in several respects; namely, the cell stores only approx.8Phi/sub 0/, employs interferometer gates and an external damping resistor, allows switching into device resonances, and eliminates the need for a special initialization cycle. The cell-selection scheme, employing triple coincidence, results in larger operating margins and smaller operating currents than have previously been achieved. The large operating margins and all basic cell design criteria were experimentally verified. The experimental interferometer gate characteristics were analyzed in detail and found to be describable by simple models. In addition, it was discovered that single flux quantum transitions in the interferometer gates could be exploited beneficially in order to enhance the insensitivity of operating margins to fabrication tolerances.

• Research Organization: IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598
• OSTI ID: 5677776
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 50:12; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COMPARATIVE EVALUATIONS
DATA
DESIGN
EFFICIENCY
ELECTRICAL EQUIPMENT
ELECTRONIC CIRCUITS
EQUIPMENT
INFORMATION
INTEGRATED CIRCUITS
INTERFEROMETERS
JOSEPHSON JUNCTIONS
MEASURING INSTRUMENTS
MEMORY DEVICES
MICROELECTRONIC CIRCUITS
RESISTORS
RESONANCE
SIMULATION
SUPERCONDUCTING DEVICES
SUPERCONDUCTING JUNCTIONS