Superconducting field-effect transistors with inverted MISFET structure

US5382565A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Johannes G. Bednorz · Adliswil, CH
• Jochen Mannhart · Eppelheim, DE
• Carl A. Mueller · Hedingen, CH

Key dates

• Filing date: Oct 20, 1993
• Grant date: Jan 17, 1995
• Expiry date: Oct 20, 2013

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S505/706

Abstract

This field-effect transistor comprises a conductive substrate (2) serving as the gate electrode, an insulating barrier layer (3), and a superconducting channel layer (1) on top of the barrier layer (3). The superconductor layer (1) carries a pair of mutually spaced electrodes (4, 5) forming source and drain, respectively. The substrate is provided with an appropriate gate contact (6). The substrate (2) consists of a material belonging to the same crystallographic family as the barrier layer (3). In a preferred embodiment, the substrate (2) is niobium-doped strontium titanate, the barrier layer (3) is undoped strontium titanate, and the superconductor (1) is a thin film of a material having a lattice constant at least approximately similar to the one of the materials of the substrate (2) and barrier (3) layers. A preferred material of this type is YBa.sub.2 Cu.sub.3 O.sub.7-.delta., where 0.ltoreq..delta..ltoreq.0.5.