| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor storage element and a nonvolatile semiconductor storage device capable of improving the controllability of a threshold voltage, inhibiting the dispersion of the threshold voltage and making the realization of the threshold voltages exceeding two kinds and the reduction of a power-supply voltage compatible. <P>SOLUTION: A channel for the nonvolatile semiconductor storage element is formed tabularly, a charge storage layer is formed on one surface of a channel region through an insulating film and a control gate electrode is formed on the charge storage layer through the insulating film. The control gate electrode is formed on the other surface of the channel region through the insulating film. The thickness of a tabular semiconductor region is formed in a thickness thinner than the double of the thickness of a maximum depletion layer determined by the impurity concentration. Accordingly, the variation of the threshold voltage with the change of the voltage of the control gate electrode can be reduced to a value exceeding a threshold value in a conventional element. Consequently, the controllability of the threshold voltage is improved and the power-supply voltage can be reduced and the nonvolatile semiconductor storage element capable of reducing a consumption power can be obtained. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
