FORMATION OF WIRING AND ELECTRODE

摘要

PURPOSE:To facilitate selective removal of underlying metal by employing a same metal as the plating metal on the surface of an original thick wiring and employing a metal removable selectively together with the original wiring and the plating metal as the underlying metal for plating. CONSTITUTION:An oxide film is deposited on GaAs and a first wiring 2 of Ti/Mo/Au is formed on the surface with Au being selected for the uppermost layer. Underlying metal tungsten 3 is then deposited and subjected to RIE at the part exposed on the bottom of an opening made in a resist 4 mask. The resist 4 is pierced wish a current supply needle 5 touching the underlying metal 3. It is then immersed into an electrolytic plating liquid of Au. Upon finishing the Au plating, the underlying metal tungsten 3 is further subjected to etching. Consequently, the first wiring 2 is made thick by plating and the plating metal is precipitated while enhancing adhesion.