Electronic devices

US5081512A · kind A · utility

Assignee

• The General Electric Company, p.l.c. · GB

Inventors

• Michael J. Kelly · Staatsburg, US
• Micahel Pepper · Cambridge, GB
• Robert Joseph Brown · Cookeville, US
• Charles G. Smith · Kalamazoo, US
• David A. Wharam · Munich, DE

Key dates

• Filing date: May 8, 1990
• Grant date: Jan 14, 1992
• Expiry date: May 8, 2010

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B82Y10/00
• WIPO field: Micro-structural and nano-technology
• WIPO sector: Chemistry

Abstract

Semiconductor apparatus comprises a split-gate semiconductor device (1) which has a first layer (3) of a first undoped semiconductor material (e.g. GaAs) and a second layer (4) of a second semiconductor material (e.g. AlGaAs) which is doped through at least part of its thickness. The second material has a higher energy band gap than the first material, and the layers form a heterojunction so that electrons from the second layer collect in the first layer to form a two-dimensional electron gas. Drain and source contacts (7,6) are provided on the second layers, and a gate electrode (8) is so configured that on application of a sufficiently large negative bias to the gate electrode a constriction is formed in the first layer through which only a one-dimensional electron gas can pass between the source and drain contacts. The apparatus also includes a bias supply (17) for applying a bias voltage between the source and drain contacts. The source/drain bias is made equal to or greater than E.sub.f /e where E.sub.f is the Fermi energy of electrons in the two-dimensional gas and e is the electron charge. As a result of the large source drain bias, the device exhibits negative resistance, a…