| 摘要 |
In a semiconductor memory device comprising semiconductor memory elements having such a degree of integration in memory circuits as to produce soft errors by incident alpha -rays derived from a packaging material and a package which packages the memory elements and is made from the packaging material, when an alpha -rays shielding layer made from a resinous material, which may contain one or more high-purity fillers, containing a total amount of 1 part per billion or less of uranium and thorium is interposed between the memory elements and the package, the generation of soft errors is reduced remarkably. |
