| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method of monitoring an erase threshold voltage distribution in a NAND type flash memory device, which can surely detect and measure the distribution of erase threshold voltage (Vt), in such a relation that a peripheral cell and a main cell mutually interfere. <P>SOLUTION: A first program voltage is applied to the main cell, and the threshold voltage is measured by programming the main cell (step 104). A programming operation, using a second program voltage and a third program voltage, is performed on the peripheral cell and the threshold voltage of the peripheral cell is measured (step 108). The threshold voltage of the main cell changed by the measured threshold voltage of the peripheral cell is measured, then the initial erase threshold voltage distribution of a page of the peripheral cell is predicted (step 114), by using an interface correlation between the measured peripheral cell and the main cell (step 112). <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
