| 摘要 |
PURPOSE:To form grooves which are actually used as elements, by a design wherein dummy grooves on which elements on a mask are not formed at the peripheral part of a pattern, in which the grooves are concentrated densely, beforehand, so that the number of the dummy grooves is determined to cover a region, where the shape becomes unstable. CONSTITUTION:The required number (since 1M pieces of capacitors are required, 1000 pieces (e) for both rows and columns) of silicon grooves 2 are provided in a memory cell part 5. In addition, two pieces (two columns or lines) of dummy silicon groove patterns 6, which are not used as cell capacitors, are formed along the sides of the outside parts of the memory cell part 5. A forming part 7 of the dummy grooves on a silicon substrate 1 is a part between the memory cell part, where the capacitors are present, and a peripheral circuit 8, where capacitors are not provided. The shapes of the grooves at the two columns (a) at the peripheral part are unstable. It is expected that the capacitance is smaller than a specified capacitance because of poor breakdown strength of a capacitor oxide film and the shallow grooves. However, lead-out electrodes are not formed at this part, and this part is not utilized as capacitors for a DRAM. |
