Field-effect semiconductor device

Abstract

Abstract PURPOSE:To protect an active layer and keep the charactaristic stable by a method wherein a surface of a n-type active layer between a gate electrode and a source-driain electrode of a GaAs Schottky gate type FET is covered by a GaAlAs layer which is thick enough to be insulating. CONSTITUTION:Liquid phase epitaxial growth of a n-type active layer 12 and, for instance, a Ga0.7Al0.3As layer 17 which the thickness large enough (approximately 1,000Angstrom ) to make the layer 17 practically insulating is made on a semi- insulating GaAs substrate 11 with a buffer layer in between. Then after an element region is determined by mesa etching, electrodes 14, 15 of, for instance An-Ge are formed and after thermal processing an alloy layer 16 is formed. Or after an impurity is injected into a source-drain region electrodes 14, 15 are formed. Then the layer 17 of the gate region is removed and an Al gate electrode 13 is formed and a FET is composed. With above method, a passivation composition which does not produce boundary level or something like that in the active region, so that a FET in which the drift of the characteristics hardly occurs and which has low noise level can be obtained.

Inventors

• 👤 Yasuo Nemoto
• 👤 Satoru Shibata
• 👤 Masumi Fukuda

Bibliographic Details