| 摘要 |
<p>PURPOSE:To realize a real electrical substitution and to perform secure and highly reliable substitution operation, by constituting a redundant part with a FAMOS, and by substituting the defective memory cell of a proper part with the memory cell of the redundant part. CONSTITUTION:1 shows an ROM body part having large capacity, 2 and 3 are an original column and a row address decoder part respectively, 4 and 5 are a column having FAMOS construction and redundant memory cell part corresponding to a row respectively, and 6 and 7 are a redundant column having FAMOS construction and row address decoder parts, respectively. If the defects of an address in the ROM body is detected by a wafer test, the said address is programmed in the redundant address decoder part formed by a FAMOS to select a redundant memory cell formed by the FAMOS, inhibit to select the defective memory cell in the body, and program the correct contents to be programmed to the memory cell to the selected redundant memory cell to complete the substitution.</p> |
