| 摘要 |
PURPOSE:To enable a uniform Au-Si alloy layer to be formed on the while rear surface of a semiconductor substrate by forming an active region in the surface of a silicon semiconductor substrate of a particular impurity concentration, and adding and forming an amorphous silicon thin film layer before forming a gold layer on the rear of the substrate. CONSTITUTION:On a semiconductor substrate 1 containing arsenic of an impurity concentration of 8X10<18> atoms/cm<3> or more, an N<-> epitaxial layer 2 is formed, a large number of active P<+> layers of diode of a P<+> region 4 and cathode electrodes 5 of aluminium are formed by conventional photoengraving and diffused evaporation processes. Thereafter, the rear is lapped, and a high-purity amorphous silicon layer 7 is formed at a normal temperature by a sputtering evaporation. Then, after forming a metal layer 6 by an evaporation process, a sintering treatment is applied at 400 deg.C or higher. Whereupon, the gold layer 6 easily reacts with the silicon of the amorphous silicon layer, becoming a liquid Au-Si compound. And, the impurity in the neighborhood of the interface of the semiconductor substrate 1 is diluted by the silicon of the amorphous silicon thin film layer 7, and reacts with the liquid Au-Si compound thereby easily forming a uniform and good Au-Si eutectic alloy in the interface of the semiconductor substrate 1.
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