| 摘要 |
PURPOSE:To provide semiconductor integrated circuit devices comprising a potential well provided on or in the semiconductor to store electric charge in which any malfunctions to be caused by alpha particles may be prevented and the working reliability is improved by coating the surface of the semiconductor device with a layer of high purity substance with impurities contained in an amount not exceeding a certain level. CONSTITUTION:In MOS-type RAM's or CCD's a well-type potential zone 18 is formed on the surface of a semiconductor substrate 11 by the electric potential of an insulating gate 16 provided on the substrate 11. Then a layer 36 of a high purity substance, say, with impurities contained at not exceeding 0.001ppm or, for example, a layer of high purity silicon, germanium, or gold having a thickness of 200mum is formed on the surface of an information memory device 35 by storage of electrons or holes in the potential zone 18. The thus formed memory device 35 is included in a package composed of alumina, ceramics, or resinous material. The layer 36 serves to shut off the alpha particles that might come out of the package due to decomposition of radioactive substances, such as uranium, contained therein, resulting in preventing the occurrence of the socalled soft errors. |
