| 摘要 |
PURPOSE:To fabricate a semiconductor memory device quite stably by reducing leak current of a capacitor insulating film thereby facilitating control of the etching end point of poly-Si film. CONSTITUTION:A contact window 11 is opened through an interlayer insulating film 4, a silicon nitride film 6 and a poly-Si film 7 on a semiconductor substrate 1, a poly-Si film 12 and a silicon oxide film 13 are then applied thereon sequentially, thereafter the silicon oxide film 13 is patterned so that it is left immediately above the contact window 11 and the periphery thereof. A poly-Si film 14 and a silicon oxide film 15 are then applied on the poly-Si film 12 and the silicon oxide film 13 being left and the silicon oxide film 15 is entirely etched back to leave it only at the outer periphery of the silicon oxide film 13. The poly-Si films 14, 12, 7 are then etched with the silicon oxide films 13, 15 as a mask until the silicon nitride film 6 is exposed with the poly-Si film 7 underneath the poly-Si film 14 being left partially between the silicon oxide films 13, 15. |
