| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce the influence of a RTS (Random Telegraph Signal) in accordance with characteristic of a non-volatile memory cell. <P>SOLUTION: A flash memory 1 has a memory array 3 and a control circuit 16. The memory array has a semiconductor substrate 30, a gate insulation film 37, and an electric charge accumulation region 36, and has a plurality of memory transistors in which a threshold value can be changed by injecting or discharging electrons for the electric charge accumulation region. Before stored information is read from the memory transistors, the control circuit applies voltage for rejecting temporarily RTS occurrence cause electrons (B) existing in a RTS depending region (A) consisting of boundaries 37A, 37C and a bulk 37B of the gate insulation film and voltage for catching temporarily the RTS occurrence cause electrons in the RTS depending region to selection terminals of the memory transistors. In the control circuit, undesired variation of the threshold voltage by influence of RTS can be reduced by performing read-out operation while adjusting a state of an electric charges of the RTS depending region. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
