Production of compound semiconductor element

Abstract

Abstract PURPOSE:To avoid reduction of electrode contact area in a mesa etching by adopting a laminated structure of Au-Ge, Pt, Mo or W as the electrode layer on an n- type GaAs crystal. CONSTITUTION:An n-and p-type GaAs films 12, 13 are superposed to an n<+>-type GaAs substrate. An AuGe film 14, Pt film 100, Mo film 15 and an Au film 16 are superposed to the substrate 11 to form an electrode layer 10. Another electrode layer 20 is formed by forming a Ti film 17, Mo film 18 and a thick Au film 19 on the layer 13. Then, a mesa etching is effected with a solution of a compound ratio of H2SO4:H2O2:H2O=4:1:1, making use of the electrode layer 10 as a mask. By so doing, Pt is diffused in the AuGe to form an Au-Ge-Au alloy so that the potential difference between the etching solution and the GaAs crystal is extinguished to prevent further etching so that the etching at the side surface, which has been inevitable in the conventional technic, is completely eliminated to avoid the reduction of the contact area between the electrode 10 and the crystal 11.

Inventors

• 👤 Eiji Murata
• 👤 Kazuhiro Arai
• 👤 Susumu Okano

Bibliographic Details