Heterostructure semiconductor device

US4755857A · kind A · utility

Assignee

• Max-Planck-Gesellschaft zur Föderung der Wissenschaften e.V. · US

Inventors

• Gerhard Abstreiter · Hallbergmoos, DE
• Klaus Ploog · Stuttgart, DE
• Albrecht Fischer · Löchgau, DE

Key dates

• Filing date: Nov 18, 1982
• Grant date: Jul 5, 1988
• Expiry date: Nov 18, 2002

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D62/824

Abstract

A heterostructure semiconductor device as a Schottky gate field-effect tristor comprises a semiconductor body including first and second layers made of different semiconductor materials, as gallium arsenide and aluminium gallium arsenide. A narrow heterojunction is formed between the layers. The material of the first layer is pure and comprises a minimum of defects. The second layer comprises a doping material, the concentration of which being at least one order of magnitude higher than the concentration of any doping or impurity material present in the first layer. The semiconductor and doping materials are chosen such that the energy levels occupied by the shallow doping material atoms in said second layer have an energetically more unfavorable position than an adjacent of the energy bands of the first layer so that free charge carriers from the doped second layer can migrate in an adjacent region of the first layer. Since the first layer has a low impurity concentration, the mobility of the charge carriers accumulating in the first layer is high, and the region containing the accumulated charge carriers can be used as channel of the field-effect transistor. Semiconductor bodies …