The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 05, 1988
Filed:
Nov. 18, 1982
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 of the described type can also be used for other semiconductor devices, as opto-electronic devices and integrated circuits.