| 摘要 |
PURPOSE:To remarkably reduce software errors of a semiconductor device by containing a semiconductor memory cell in a package removed of radioactive substance. CONSTITUTION:A cap 2 and an adhering glass are introduced into a nuclear reactor, and neutron beam containing, for example, 1X10<21> pieces/cm<2> in intensity is irradiated thereto. As a result, radioactive substance such as uranium or the like in the small amount in the cap and the adhering glass conduct unclear fission and accordingly scatter with large kinetic energy thus obtained to be removed from the cap and the adhering glass, with a result that the residual radioactive substance becomes substantially one-half. When the neutron beam is reduced to 4X10<21> pieces/cm<2>, it is reduced to 10% of the initial value. Accordingly, no harm occurs eveven if it is used for the package substrate. According to this configutation, software errors are remarkably reduced in the semiconductor device. |
