| 摘要 |
PURPOSE:To reduce the dimensional change, to increase the region of a capacitor and to contrive improvement in holding characteristics of information by a method wherein the element isolation insulating film located between capacitors is formed thinner than the element isolation insulating film of the side part of the switching element which constitutes a memory cell. CONSTITUTION:The thermally oxided mask 21 formed on the whole surface of a semiconductor substrate 1 becomes the mask which will be used in thermal oxidization process in which a field insulating film 10 is formed on regions A and B and a thin field insulating film 11 formed on the region A. The mask 22, consisting of resist, in which an aperture is provided on the part which will be turned to the insulating films 10 and 11, is formed on a memory cell region in the region A, and also the mask 22 is formed on a p-channel MISFET (metal insulating semiconductor field effect transistor) region and an n-channel MISFET region in the region B. Then, the base film 15 is exposed by selectively removing the mask 21, and p-type impurities 23, to be used for formation of a p-type channel stopper region 12, is introduced into the surface of the substrate 1, which is exposed from the mask 22, by performing ion implantation. The insulating film 11 is larger than the size of the aperture of the mask 21 and it is formed with the difference in dimensional change, but as it has thin film thickness, its difference in dimensional change is small, and especially, the reduction in the capacitor region of the region A due to a bird's beak is small. |
