| 摘要 |
PURPOSE:To form an electrode with excellent ohmic contact with GaAlAs and excellent adhesion to an insulating film by a method wherein a process to laminate Cr layer, Zn layer and Au layer successively on a P type GaAlAs crystal and another process to heat-treat all of the formed layers are provided. CONSTITUTION:Island type Cr layers 12 are formed on a P type Ga0.55Al0.45As single crystal 11. The Cr layers 12 may be formed into island type economically owing to surface tension by means of e.g. Cr evaporation process on the single crystal 11. Next a Zn layer 13 and an Au layer 14 are successively formed on the Cr layers 12 to be heat-treated at the temperature of around 350 deg.C. Consequently all layers are alloyed while an alloy layer 15 may come into excellent ohmic contact with the single crystal 11 because the Zn layer 13 comes into direct contact with the surface of single crystal 11 due to the island type of Cr layers 12 while Zn is directly diffused in Ga0.55Al0.45As single crystal 11 in case of the heat-treatment process. Besides, when the alloy layer 15 comprising said three layers is formed on the insulating film such as SiO2, Al2O3 etc., the alloy layer 15 may be provided with excellent adhesion due to Cr layers 12 filling the role of bonding layers. |
