| 摘要 |
PURPOSE:To prevent the contamination of the surface of an electrode due to the diffusion of group III atoms at the time of heat treatment, and to increase the strength of wire bonding by forming a barrier layer onto an ohmic layer. CONSTITUTION:An ohmic layer 2 is shaped onto a III-V compound semiconductor substrate 1, and a barrier layer 3 and a gold layer 4 are formed onto the ohmic layer 2 in succession. The barrier layer 3 is constituted of a Ti layer 3a, an Mo layer 3b and a Ti layer 3c successively. That is, since Mo has inferior adhesive properties with Au, the Ti layers 3a, 3c having extremely excellent adhesive properties with both Mo and Au are shaped to the upper and lower sections of the Mo layer 36, and the adhesive properties of the Mo layer 3b with each of an Au layer 2c as the uppermost layer of the ohmic layer 2 and the Au layer 4 of the uppermost surface of an electrode are improved. Accordingly, the barrier layer stops the diffusion and permeation of Ga due to heat treatment, thus preventing the contamination of the surface of the electrode by group III atoms.
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