| 摘要 |
PURPOSE:To improve breakdown strength of an oxide film by forming a trench structure, rounding the corners of the top of the trench and forming an oxide film, an insulating film of a capacitor, thereon. CONSTITUTION:A thin film 2 is formed on a trench and the surface part of its periphery, a nitride film 3 is grown on the film 2, the film 3 is removed except the trench and its surface except the corners, and a thick oxide film 4 is further formed. Then, the films 3, 4 are removed, and the corners of the top of the trench are rounded. Then, an oxide film 5 of the insulating film of a capacitor is formed, a polycrystalline silicon layer 6 is so grown by a chemical vapor growing method as to bury the trench part on the film 5, and selectively etched to form a capacitor. Thus, the breakdown strength of the film 5 of the insulating film of the capacitor is improved. |
