| 摘要 |
PURPOSE:To make it possible to avoid definitely adverse effect based on the generation of charge induced by alpha line by forming a region which increases the concentration of impurities in a well an a region which reduces the impurities on the other hand. CONSTITUTION:A memory formation section is adapted to remain by conducting selective etching based on photo lithography so that an opening section 31 may be formed in an element dielectric isolation layer or a section where LO COS must be formed. Deep ion implantation is carried out by selecting implantation energy, which forms an impurity implantation region 14 and further forms a shallow impurity implantation region which forms a channel stop region 12 by less implanting energy. It is, therefore, possible to inhibit the charge of one party of polarities directed at a memory cell even carriers (charges) are generated at the depth of a base body 1 induced by alpha-rays. More specifically, this construction makes it possible to protect this memory cell from memory destruction and malfunction. |
