DRY ETCHING METHOD FOR COMPOUND SEMICONDUCTOR

摘要

PURPOSE:To regulate with high precision the width of a pattern in a compound semiconductor base by a method wherein a second film with an opening smaller than an opening in a first film provided on the semiconductor base is used as a mask for etching said base. CONSTITUTION:Reactive neutral particles 11 remaining not activated spread side- wise and arrive at a d1-width region in an opening 7 provided in an SiO2 film 3. The surface of an active layer 2 is coated with an oxide film 9. The active layer 2 and oxide film 9 being differently responsive to an etching gas, ethcing by the neutral particles 11 of the active layer 2 facing the d1 region is impeded. With etching proceeding only in a region defined by the width d2 of the opening 8 in the resist 4, the width d is nearly equal to the width d2.