Electrode for compound semiconductor

TL;DR: In this paper, the authors proposed to obtain an electrode having excellent heat resistance by repeatedly depositing laminated layers of diffusion barrier layers and soft metal layers, whose thicknesses are controlled so as not to yield cracks, on an ohmic connecting layer on a compound semiconductor substrate.

Abstract: PURPOSE: To obtain an electrode having excellent heat resistance, by repeatedly depositing laminated layers of diffusion barrier layers and soft metal layers, whose thicknesses are controlled so as not to yield cracks, on an ohmic connecting layer on a compound semiconductor substrate. CONSTITUTION: Mo 32 is evaporated on a P-type GaAs substrate 31. The Mo 32 also serves the role of a barrier for preventing external diffusion of Ga and As from an ohmic electrode and the substrate. Then, soft metal Au 33 is evaporated in a vacuum. An Mo diffusion preventing film 34, an Au film 35, an Mo diffusion preventing film 36 and an Au film 37 are evaporated in a vacuum. Thus an ohmic electrode is completed. In this way, the diffusion preventing Mo film is divided into a plurality of layers. The thickness of each layer is controlled so that cracks are not yielded in heat treatment during alloy processing and element processes. Then, the electrode having an excellent barrier effect and heat resistance is obtained. COPYRIGHT: (C)1986,JPO&Japio