| 摘要 |
PURPOSE:To enable to accomplish the characteristics differing between the memory cell part and the circumferential circuit part of the titled device by a method wherein the raised-up quantity of the impurities from a buried layer to an epitaxially grown layer for the memory cell part is made larger than that for the circumferential circuit part. CONSTITUTION:A silicon dioxide film is grown on a silicon substrate 1, and after an aperture has been selectively formed thereon, an As-doped silica film 3 is applied. Subsequently, a buried layer 4 is formed by performing push-off diffusion, and a silicon dioxide film is formed by oxidizing the aperture part on the film 2. Besides, an aperture is selectively provided at the part which will be turned to the buried layer of the transistor of the memory cell part, As is implanted by performing an ion implantation 10, and a diffusion layer 5 is formed by performing a heat treatment. Subsequently, an epitaxially grown layer 6 is formed, and then the prescribed diffusion layers such as a base layer, an emitter layer and the like are formed. |
