| 摘要 |
PURPOSE:To improve the off characteristic of a bipolar-type SIT by having a pattern on the interior circumference edge of a floating gate layer with a polygon type of more than a pentagon or a round shape, and by having the interior circumference pattern of a control gate layer corresponding to the above. CONSTITUTION:In case a channel width or a gate clearance is not uniform, a depletion layer is pinched off at the section where the channel width is narrow, but it is not sufficiently pinched off at the section with a wider width. Besides the distance from the gate to the section is long and the barrier formed by a diffusion potential is low. Therefore, a sharp cut-off characteristic can not be obtained. Accordingly, in the case of a bipolar type SIT as a flat pattern of the floating gate layer 20 is made round corresponding to the interior circumference edge of a control gate layer 18, the width of a channel 16A or a gate clearance becomes a uniform value a and the off characteristic can be improved. |
