570-ps 13-m W Josephson 1-kbit NDRO RAM

Journal Article · Sun Oct 01 00:00:00 EDT 1989 · IEEE Journal of Solid-State Circuits (Institute of Electrical and Electronics Engineers); (USA)

DOI:https://doi.org/10.1109/JSSC.1989.572615· OSTI ID:7140234

Nagasawa, S; Wada, Y; Hidaka, M; Tsuge, H; Ishida, I; Tahara, S ^[1]

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1. Microelectronics Research Labs., NEC Corp., Ibaraki (JP)

This paper reports Josephson 1-kbit random access memories (RAM's) fabricated using Nb multilayer planarization technology with Nb/AlO{sub {ital x}}/Nb junctions and Mo resistors. The RAM design has been reported previously. The RAM consists of a 32 {times} 32-bit nondestructive readout (NDRO) memory cell array and peripheral circuits. The NDRO memory cell consists of a loop storing three flux quanta and two 3-junction interferometer gates. The peripheral circuits consist of decoders with address inverters, drivers, a sense circuit, and reset circuits, where resistor-coupled Josephson logic (RCJL) circuits are used as basic circuits. The RAM circuit size is 4.4 {times} 4.4 mm{sup 2}, and the memory cell size is 65 {times} 65 {mu}m{sup 2}. About 10000 Nb/AlO{sub {ital x}}/Nb junctions with 1030-A/cm{sup 2} critical current density were contained in the RAM. Minimum line and space widths were 3 and 2 {mu}m, respectively. The Mo resistors had 1.2 {approximately} 1.3 {Omega} sheet resistance. ABout 40 percent of the bits were successfully operated with a {+-} 18-percent bias margin. A minimum 570-ps access time with 13-mW power dissipation was obtained for the highest peripheral circuit bias conditions.

• OSTI ID: 7140234
• Journal Information: IEEE Journal of Solid-State Circuits (Institute of Electrical and Electronics Engineers); (USA), Vol. 24:5; ISSN 0018-9200
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
JOSEPHSON JUNCTIONS
FABRICATION
MOLYBDENUM
RESISTORS
NIOBIUM
SUPERCONDUCTIVITY
ALUMINIUM OXIDES
LOGIC CIRCUITS
MEMORY DEVICES
ALUMINIUM COMPOUNDS
CHALCOGENIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
ELECTRONIC CIRCUITS
ELEMENTS
EQUIPMENT
JUNCTIONS
METALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SUPERCONDUCTING JUNCTIONS
TRANSITION ELEMENTS
426001* - Engineering- Superconducting Devices & Circuits- (1990-)