SURFACE TREATMENT FOR BASE OF COMPOUND OF GROUP 3-5

摘要

PURPOSE:To carry out the surface treatment of a base without making the surface rough, and to remove an oxidized film, by etching the base of an aluminum- containing compound of the group III-V with the first solution containing an alkali, followed by etching it with the second solution containing an acid. CONSTITUTION:A base 1 (e.g., one using three component mixed crystal Ga0.3Al0.7As) of an aluminum-containing compound of the group III-V, having the formed oxidized film 2 on the surface, is etched with the first solution (e.g., NaOH aqueous solution) containing an alkali. Aluminum oxide is removed, and the modified layer 3 consisting essentially of Ga oxide is formed. The base is etched with the second solution (e.g., sulfuric acid or phosphoric acid aqueous solution) containing an acid, and the modified layer 3 is removed. After the removal of them, the surface 4 of the base keeps mirror face. When an electrode is formed, an ohmic contact can be obtained easily.