| 摘要 |
PURPOSE:To obtain the electrode with good reproducibility, when the electrode is provided in the compound semiconductor including Al, by forming the three layer structure of the electrode comprising a Ti layer which is provided on the substrate, a layer including a metal which is ohmic-contacted with the Ti layer, and an Au layer. CONSTITUTION:On the P type GaAs substrate 1, a P type GaAlAs region 2 and an N type GaAlAs region 3 are laminated and grown by a liquid phase epitaxial growth. The Ti layer 7 which is to become a protecting film at the time of chemical etching, the mixed metal layer 8 of Ge and Ni which is excellently ohmic-contacted by the diffusion at the later heat treatment, and the Au layer 9 which is readily bonded to lead wire are laminated and deposited on the layer 3. Then a heat sensitive film 10 having a fine pattern is provided on a layer 9. At first, the exposed part of the layer 9 is etched away, then the layer 8 is etched away by using a mixed liquid of KI-I2. Thereafter, the layer 7 is plasma- etched by using a gas such as CF4, the film 10 is removed, and an electrode 5 such as Au-Zn is deposited on the back surface of the substrate 1. Thereafter, the heat treatment is performed. Thus the electrode having the excellent three layer structure is obtained on the surface of the substrate 1. |
