memory devices

Abstract

This invention reduces the manufacturing cost of memory devices. An embodiment of the memory device 1 includes a plurality of conductive layers 24, an insulating film 51, and a plurality of contact plugs CC, arranged throughout layers TLCA and TUCA. Each of the plurality of conductive layers 24 has a high-dielectric film 54. The upper surface of the insulating film 51 has a step along a stepped shape formed by the plurality of conductive layers 24a included in the layer TLCA. The insulating film 51 is thicker than the conductive layers 24a and includes a high-dielectric film 52 of the same material as the high-dielectric film 54. The plurality of contact plugs includes a plurality of contact plugs CCa respectively connected to the plurality of conductive layers 24a. Each of the plurality of contact plugs CCa includes a sub-contact plug LCC having a portion passing through the layer TLCA and the insulating film 51, and a sub-contact plug UCC having a portion passing through the layer TUCA.

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