Semiconductor device with damascene bit line and method for fabricating the same

摘要

A semiconductor device includes a substrate having a plurality of contact surfaces, an interlayer dielectric layer formed over the substrate and having a first open portion which exposes a part of the contact surfaces and a second open portion which exposes the other contact surfaces, a storage node contact (SNC) plug filling the first open portion, and a damascene structure filing the second open portion and including a bit line, a spacer formed on both sidewalls of the bit line, a capping layer formed over the bit line and the spacer, and an air gap formed between the bit line and the spacer. The bit line includes a conductive material of which the volume is contracted by a heat treatment to form the air gap.

主权项

1. A semiconductor device comprising:
a substrate having a plurality of contact surfaces; an interlayer dielectric layer formed over the substrate and having a first open portion which exposes a part of the contact surfaces and a second open portion which has a line shape to expose the other contact surfaces and a first portion between two adjacent contact surfaces among the other contact surfaces; a storage node contact (SNC) plug filling the first open portion; and a damascene structure filing the second open portion and comprising a bit line, a spacer formed on at least both sidewalls of the bit line, and an air gap that is formed between the bit line and the spacer, wherein uppermost portions of the other contact surfaces include a metal silicide, the spacer is further formed under the bit line and the air gap in a region overlapping with the first portion, and a bottom surface of the bit line directly contacts the metal silicide except for the region overlapping with the first portion.