Selective etching process

• Main Authors: BILAKANTI, JAYA, LASKOWSKI, EDWARD JOHN
• Format: Patent
• Language: English; French; German
• Published: 27.02.1991
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

An etching process is described for etching aluminum containing III-V semiconductor compounds. The etch solution contains dichromate ion in acid aqueous solution in which the acid is either phosphoric acid or sulfuric acid. The etch solution is highly selective in that it etches the aluminum containing III-V semiconductor compounds without etching significantly other III-V semiconductor compounds not containing aluminum exposed to the same etching solution. The etching process is extremely useful in fabricating a variety of III-V semiconductor devices including heterojunction bipolar transistors, heterojunction field effect transistors and self-enhanced electro optic devices.