| 摘要 |
PURPOSE:To decrease the MOS capacity and variations thereof at an electrode part and reduce such failures as disconnection of an electrode metal at a step, through formation of an electrode on an exposed semiconductor substrate, by forming a second insulating film on a first insulating film formed on a semiconductor substrate, and providing an opening region in the second insulating film. CONSTITUTION:On a silicon substrate 21, an oxide film 22 is formed as a first insulating film by thermal oxidation. A contact hole is formed in the insulating film 22, and on the whole surface, a silicon nitride film 24 and a silicon oxide film 25 are formed as second and third insulating films, respectively. Then, a hole is opened in the oxide film 25, and the nitride film 24 is etched to expose the surface of the substrate 21. Titanium 26 and aluminum 23 are successively deposited on the whole surface by evaporation to form an electrode. Since the contact hole is previously opened in the silicon oxide film 22 as a ground, it is possible to decrease variations of the diameter thereof, and there will be no change in size of the diameter in steps carried out subsequent thereto. Moreover, since it is possible to enlarge the silicon oxide film thickness while maintaining the size of the contact hole, the MOS capacity can be decreased. Also, there will be fewer problems of disconnection of the electrode metal at a step, since two layers of silicon oxide film are provided with the silicon nitride film interposed therebetween. |
