| 摘要 |
PURPOSE:To eliminate nonuniformity in the width of a word line and to dispense with disposition of a dummy word line by using a mask on which the width of a light-shielding film corresponding to the word line in the edge part of an active region array is made smaller than that of the film corresponding to the word line in the central part of the array. CONSTITUTION:A field oxide film 2 is formed by oxidizing the surface part of a P-type silicon substrate 1 selectively and active regions are sectioned. Next, gate oxide films 3 are formed on the surfaces of the active regions. These active regions are disposed at prescribed pitches in the two direction. Besides, a light-shielding film on a mask corresponding to a word line 4A in the end part of a memory cell array is made thinner in width than the light-shielding film corresponding to a word line 4 in the central part of the array. By this method, the thickness of the word lines can be formed uniformly over the whole area of the memory cell array and a dummy word line is dispensed with. Besides, the size of the memory cell array in the direction of a bit line can be reduced by the a size corresponding to two word lines. |
