| 摘要 |
PURPOSE:To reduce a value of contact resistance and obtain a uniform electrode by forming the electrode by application of a laser beam to a window for electrode in a semiconductor substrate in vacuum and then by evaporation of metal thereon. CONSTITUTION:An n layer is provided on the P type substrate, while the window for electrode is provided in an SiO2 film 3. The laser beam is applied in vacuum and the surface of the n layer 2 thus exposed in heated at high temperature. By this heating, impurities, organic substances and the thin SiO2 film on the surface are vaporized and thereby the surface is purified. Al7 is evaporated immediately, whereon an alloy film 8 such as Si and further Cu is laid. Finally, the metal films 7 and 8 are etched selectively, thereby an electrode pattern is provided, the device thus prepared is processed in N at about 400 deg.C, Si and metal are alloyed on the interface between the film 7 and the n layer 2, and thus ohmic connection is completed. By this method, cooling is performed in a short time since the uppermost surface layer of the substrate alone is heated, and thus the electrode which has low value of contact resistance and uniformity can be obtained. |
