| 摘要 |
PURPOSE:To prevent short circuits from occurring between word lines attendant on the densification of a memory device so as to offer a DRAM of high reliability by a method wherein a thickness transition region is provided to a field insulating film, and the end of a plate electrode is located at the thickness transition region. CONSTITUTION:When a field insulating film 3S under a plate electrode 6 is made thinner than a field insulating film 3 located under a part other than the electrode 6, the end of the plate electrode 6 is located at the thickness transition region of the insulating film 3, so that the plate electrode 6 is so structured that its end is sloped when the plate electrode 6 is processed using a resist pattern R as a mask, and provided that the thickness of a plate electrode is represented by t, and when the plate electrode is patterned under such an etching condition that a pattern conversion difference is made to become equal to G, the angle of the processed face of the plate electrode end is equal to an angle of theta1, but as the end of the plate electrode is located on a sloping region, an angle of theta2 actually formed by the processed face with a horizontal plane satisfies a formula, theta2=theta1-alpha. By this setup, the angle of the processed face of a plate electrode can be made small at processing without making a conversion difference large. |
