US 4,498,228 AGranted

Method of manufacturing Josephson junction integrated circuits

AssigneeSperry Corporation

InventorsDon W. Jillie, Jr., Lawrence N. Smith

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Abstract

Josephson junction integrated circuits of the current injection type and magnetically controlled type utilize a superconductive layer that forms both Josephson junction electrode for the Josephson junction devices on the integrated circuit as well as a ground plane for the integrated circuit. Large area Josephson junctions are utilized for effecting contact to lower superconductive layers and islands are formed in superconductive layers to provide isolation between the groundplane function and the Josephson junction electrode function as well as to effect crossovers. A superconductor-barrier-superconductor trilayer patterned by local anodization is also utilized with additional layers formed thereover. Methods of manufacturing the embodiments of the invention are disclosed.

Claims21

Dependent claims

A method of fabricating a superconductive integrated circuit including at least one Josephson tunnel junction, said tunnel junction including first and second tunnel junction electrodes superposed with respect to each other with a Josephson tunneling barrier therebetween for conducting Josephson tunneling current between said first and second tunnel junction electrodes, said method comprising the steps of

forming a ground plane for said integrated circuit and forming said first tunnel junction electrode by depositing a first layer of superconductive material on a substrate, said first layer comprising said ground plane as well as including said first tunnel junction electrode,
forming a first layer of insulative material on said first layer of superconductive material,
forming at least one opening through said first layer of insulative material,
forming said Josephson tunneling barrier within said opening in said layer of insulative material, and
depositing a second layer of superconductive material on said layer of insulative material, said second layer including said second tunnel junction electrode.

2 more elements

A method of fabricating a superconductive integrated circuit including a plurality of Josephson tunnel junction, each said tunnel junction including first and second tunnel junction electrodes superposed with respect to each other with a Josephson tunneling barrier therebetween for conducting Josephson tunneling current between said first and second tunnel junction electrodes, said method comprising the steps of

forming a ground plane for said integrated circuit and forming said first tunnel junction electrode of each said Josephson tunnel junction by depositing a first layer of superconductive material on a substrate, said first layer comprising said ground plane as well as including said first tunnel junction electrode of each said Josephson tunnel junction,
forming a barrier layer on said first layer of superconductive material, said barrier layer including said Josephson tunneling barrier of each said Josephson tunnel junction,
depositing a second layer of superconductive material on said barrier layer, said second layer including said second tunnel junction electrode of each said Josephson tunnel junction,
anodizing said second layer of superconductive material through to said barrier layer except at the locations of said Josephson tunnel junctions so as to define said Josephson tunnel junctions,
said first and second layers of superconductive material with said barrier layer therebetween and with said second layer of superconductive material anodized through to said barrier layer, with said Josephson tunneling junctions defined by the unanodized areas, comprising a trilayer, and
depositing a third layer of supercondutive material superposed with respect to said trilayer making electrical contact with said second layer of supercondutive material.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/550,847Filed 14 Nov 1983 · division
Priority: 9 Apr 1981
Granted: 12 Feb 1985
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H10N 60/0912
Manufacture or treatment: of Josephson-effect devices
H10N 69/00
Integrated devices, or assemblies of multiple devices, comprising at least one superconducting
Y10S 505/874
Active solid-state device: with josephson junction, e.g. squid
Y10S 505/922
Mechanically manufacturing superconductor: making josephson junction device