| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain aprogramming method for a non-volatile memory in which the time required for performing programming operation can be minimized by control of gate voltage. SOLUTION: Threshold voltage in which a value is increased for a pre- programming pulse at the time of programming is applied to a gate terminal of each cell to be programmed, and an increment of threshold voltage of a cell to be programmed is made equal to an increment of gate voltage (ΔVcp). Variation interval of threshold voltage relating to each level is held at a small value to move from one threshold level to a next threshold level, in order to reduce a whole programming time, continuous pulses are supplied to each cell to be programmed with non-verifying until it is reduced to a voltage level to be programmed or less (107-109), and a verifying process (110) is performed, successively, a programming process and a verifying process (112, 110, 117, 118) are continuously performed until a cell to be programmed reaches the desired threshold value.</p> |
