Feasibility of an ultra-high-speed Josephson multiplier

Journal Article · Sun Feb 01 04:00:00 EST 1987 · IEEE J. Solid-State Circuits; (United States)

DOI:https://doi.org/10.1109/JSSC.1987.1052677· OSTI ID:6411398

Kotani, S; Fujimaki, N; Morohashi, S; Ohara, S; Hasuo, S

In this paper, the authors discuss the design, fabrication, and evaluation of a Josephson multiplier model featuring all niobium junctions. They designed a 16-bit X 16-bit parallel multiplier and fabricated its critical path model consisting of 828 gates. The circuit was designed using modified variable threshold logic (MVTL) or gates and single-junction AND gates. These gates consisted of Nb/AlO/sub x//Nb Josephson junctions, Nb wirings, Mo resistors, and SiO/sub 2/ insulators. Both the minimum linewidth and junction diameter were 2.5 ..mu..m. The observed multiplication time using the critical path model was 1.1 ns. The propagation delay due to the interconnecting wirings was estimated to be 0.20 ns, and the longest path of the circuit consisted of 103 gates. Thus the average gate delay in the circuit was estimated to be 8.7 ps/gate. These results point to the possibility of an ultra-high-speed multiplier, about five times faster than any other semiconductor device.

• Research Organization: Fujitsu Ltd., 10-1, Morinosato-Wakamiya, Atsugi-shi 243-01
• OSTI ID: 6411398
• Journal Information: IEEE J. Solid-State Circuits; (United States), Journal Name: IEEE J. Solid-State Circuits; (United States) Vol. SC-22:1; ISSN IJSCB
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420201* -- Engineering-- Cryogenic Equipment & Devices
420800 -- Engineering-- Electronic Circuits & Devices-- (-1989)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
99 GENERAL AND MISCELLANEOUS
990220 -- Computers
Computerized Models
& Computer Programs-- (1987-1989)
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
DESIGN
ELECTRICAL EQUIPMENT
ELECTRICAL INSULATORS
ELECTRONIC CIRCUITS
ELEMENTS
EQUIPMENT
FABRICATION
FEASIBILITY STUDIES
GATING CIRCUITS
JOSEPHSON JUNCTIONS
JUNCTIONS
LINE WIDTHS
LOGIC CIRCUITS
METALS
MOLYBDENUM
NIOBIUM
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE TESTING
PERT METHOD
RESISTORS
SILICON COMPOUNDS
SILICON OXIDES
SUPERCONDUCTING JUNCTIONS
TESTING
TIME MEASUREMENT
TRANSITION ELEMENTS
WIRES