Contact structure and semiconductor memory device including the same

Abstract

Provided are a contact structure and a semiconductor memory device including the same. The contact structure includes a contact insulation layer defining a preliminary contact hole, a first insulating spacer extending along a side of the preliminary contact hole, a second insulating spacer provided on an upper portion of a side surface of the first insulating spacer, and a contact filling a contact hole defined by the first insulating spacer and the second insulating spacer. Each of the contact provided on a lower portion of the side surface of the first insulating spacer and the contact provided on a side surface of the second insulating spacer has a width that changes in a direction from a bottom surface of the contact toward an upper surface thereof. A maximum width of the contact provided on the bottom surface of the second insulating spacer is greater than a minimum width of the contact provided on the side surface of the second insulating spacer.

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