| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method of trimming threshold voltage applied to an over-programmed field effect transistor (FET) nonvolatile memory (NVM) cell. <P>SOLUTION: The method comprises: (a) applying first voltage and second voltage to a control gate and a body of the over-programmed FET NMV cell, respectively; and (b) applying a signal to a drain of the over-programmed FET NVM cell within the prescribed time period to produce a limited threshold voltage reduction, wherein polarities of the first voltage and the second voltage are opposite to that of the signal. Thus, the charge placement in storing material can be precisely controlled within a small range of a specific charge state, further, higher digital storage density can be attained. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
