Semiconductor memory device
A semiconductor memory device, and a method of manufacturing the semiconductor memory device, includes a gate stack including interlayer insulating layers and word lines alternately stacked in a first direction, channel pillars passing through the gate stack and tapering toward the first direction, source select lines surrounding the channel pillars and extending to overlap the gate stack, and a source isolation insulating layer overlapping the gate stack between the source select lines and tapering toward a direction opposite to the first direction.
1. A semiconductor memory device comprising:
a gate stack including interlayer insulating layers and word lines alternately stacked in a first direction;
channel pillars passing through the gate stack and tapering toward the first direction;
source select lines surrounding the channel pillars and extending to overlap the gate stack; and
a source isolation insulating layer overlapping the gate stack between the source select lines and tapering toward a direction opposite to the first direction.
2. The semiconductor memory device of claim 1 , wherein the gate stack further comprises:
drain select lines respectively overlapping the source select lines with the word lines interposed between the drain select lines and the source select lines; and
a drain isolation insulating layer disposed between the drain select lines and tapering toward the first direction.
3. The semiconductor memory device of claim 2 , wherein the source isolation insulating layer overlaps the drain isolation insulating layer.
4. The semiconductor memory device of claim 2 , wherein:
the channel pillars include a first channel pillar and a second channel pillar;
the drain select lines include a first drain select line surrounding the first channel pillar and a second drain select line surrounding the second channel pillar, wherein the second drain select line is spaced apart from the first drain select line by the drain isolation insulating layer; and
the source select lines include a first source select line surrounding the first channel pillar and a second source select line surrounding the second channel pillar, wherein the second source select line is spaced apart from the first source select line by the source isolation insulating layer.
5. The semiconductor memory device of claim 1 , wherein each of the source select lines includes silicon.
6. The semiconductor memory device of claim 1 , wherein each of the source select lines includes:
a silicon layer; and
a metal silicide layer that is in contact with the silicon layer between the silicon layer and the source isolation insulating layer.
7. The semiconductor memory device of claim 1 , wherein:
each of the source select lines includes a silicon layer and a sidewall conductive pattern disposed between the silicon layer and the source isolation insulating layer; and
the sidewall conductive pattern includes a metal barrier layer that is in contact with the silicon layer, and a metal layer disposed between the metal barrier layer and the source isolation insulating layer.
8. The semiconductor memory device of claim 1 , wherein the source select lines and the word lines include the same conductive material.
9. The semiconductor memory device of claim 8 , wherein each of the source select lines includes conductive patterns of at least two layers stacked to be spaced apart from each other in the first direction.
10. The semiconductor memory device of claim 1 , further comprising:
a common source layer in contact with the channel pillars, wherein the common source layer overlaps the gate stack with the source select lines interposed between the common source layer and the gate stack;
a bit line connected to the channel pillars, wherein the bit line overlaps the common source layer with the gate stack interposed between the bit line and the common source layer; and
a peripheral circuit structure overlapping the gate stack with the bit line interposed between the peripheral circuit structure and the gate stack.