| 摘要 |
In a non-volatile semiconductor memory composed of floating gate field effect transistors arranged in rows and columns forming an array, a redundancy method is provided which includes the steps of: providing one or more column lines for redundancy, in which floating gate FETs in a number as many as the row lines of the array are connected; when a defect occurs in a column line, setting the thresholds of at least all the floating gate FETs connected to the defective column line, to the high state; and using as the substitute memory, the floating gate FETs for redundancy connected to redundancy column lines in a number as many as those of the floating gate FETs of which the thresholds are set in the high state.
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