Characterization of amorphous silicon-barrier Josephson junctions, resonant tunneling, and circuit applications

Miscellaneous · Fri Jan 01 00:00:00 EST 1988

OSTI ID:7154773

Bradley, P D

The author studied the effect of processing conditions on the quality of silicon-barrier junctions and obtained junctions with low leakage. Amorphous silicon-barrier Josephson junctions were chosen with two goals in mind. One goal was to study the effect on junction behavior of localized electron states in the tunnel barrier, primarily, to see the effects of resonant tunneling. Oxidized silicon has a much lower density of localized states than amorphous silicon, so the density of states are reduced in a layer of the barrier by growing a thermal oxide on silicon. Tunnel barriers of a fixed thickness were fabricated, composed mostly of amorphous silicon, but containing a thin silicon oxide layer. An expression was derived for the conductance due to resonant tunneling in these structures as a function of the location of this oxide layer, and good agreement with experimental results was found. The other goal was the use of these barriers in circuits because of their low capacitance relative to other materials that have been shown to form good-quality junctions. This leads to higher-speed operation of Josephson circuits, everything else being fixed. A new shift register design was simulated at clock rates as high as 20 GHz. A new design for a Josephson memory circuit was simulated at sub-nanosecond cycle times and a single cell was successfully tested.

• Research Organization: California Univ., Berkeley, CA (USA)
• OSTI ID: 7154773
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
JOSEPHSON JUNCTIONS
FABRICATION
SILICON
SCHOTTKY BARRIER DIODES
AMORPHOUS STATE
ELECTRONIC CIRCUITS
TUNNEL EFFECT
ELEMENTS
JUNCTIONS
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES
SEMIMETALS
SUPERCONDUCTING JUNCTIONS
426001* - Engineering- Superconducting Devices & Circuits- (1990-)