Superconductive tunnel junction device and method of manufacture
AssigneeSperry Corporation
InventorHarry Kroger
Life of this patent
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Abstract
A Josephson tunnel junction device having niobium nitride superconductive electrodes includes a polycrystalline semiconductor tunneling barrier therebetween comprised of silicon, germanium, or an alloy thereof preferably deposited on the lower superconductive electrodes by vapor deposition. The barrier thickness of the junction is controlled by precision doping of the semiconductor material. The active junction is defined after the interfaces between the barrier material and the two superconductor lines are formed, retaining those active interfaces in fully unpolluted character.
Claims15
A method of manufacturing a superconductive tunnel junction device including at least one superconductive tunnel junction defined as a predetermined active region comprising the steps of
- forming a first layer of superconductive material on said substrate,
- forming a barrier layer of barrier material on said first layer,
- forming a second layer of superconductive material on said barrier layer, and
- rendering insulating at least the entire thickness of said second layer of superconductive material except at said predetermined active region for defining said tunnel junction, and with the exception of said first layer of superconductive material which remains substantially unconverted to insulating material,
- the unconverted second layer at said predetermined active region providing an upper electrode for said tunnel junction, the barrier layer underlying said upper electrode providing a tunnelling barrier for said tunnel junction and the unconverted first layer underlying said tunnelling barrier providing a lower electrode for said tunnel junction,
- electrical contact to said lower electrode being effected through the unconverted first layer laterally adjacent said predetermined active region.
Dependencies are inferred from the claim text.