| 摘要 |
<p>PURPOSE:To obtain a redundant circuit having superior holding characteristic in the OFF state of circuit by constituting with nonvolatile semiconductor memory cells capable of writing which are vertically put with plural fuse elements. CONSTITUTION:Two fuse cells MEE1, MEE2 are used and the changeover can be made at the same time for two cells. A common potential is supplied for a source potential VS and the changeover is made by utilizing an F-N tunneling. The fuse cell information is received by a buffer Buf and outputted to an output O. Both gate voltages VG1, VG2 of fuse cells MEE1, MEE2 are a power source voltage at the normal using time, and when either one threshold at least is higher enough, the information of OFF state can be continuously supplied to the output O, and also even when the cells are erroneously changed over, they can be returned to the ON state. Thus, a sufficient reliability can be given to the holding characteristic in the OFF information of circuit.</p> |
