| 摘要 |
PURPOSE:To improve breakdown strength by constituting obtuse angle arrangement with respect to an upper surface part and a side surface part, on the peripheral part between the upper surface part and the side surface part of a plurality of stack electrodes, and relieving the concentration of electric field. CONSTITUTION:By thermally oxidizing an N-type silicon substrate 1, an oxide film 2 is formed; a contact hole is formed, and a substrate 1 of a desired region is exposed; a polysilicon layer 4 is grown, and therein phosphorus is diffused to increase conductivity; the silicon layer 4 and the substrate 1 are electrically connected; after a silicon nitride film 5 is grown, an initial shape processing is performed; further thermal oxidation is performed, and an oxide film 6 is formed on the silicon layer 4; by using a silicon layer 6 as a mask, etching is performed, thereby forming a plurality of stack electrodes. By using the silicon film 6, the electrodes are subjected to formation of an inclined surface of the periphery and patterning, and all angles of electrode periphery are turned into obtuse angles. Thereby the concentration of electric field is restrained, and a shape of large breakdown strength can be obtained. |
