Vertical semiconductor device with lower pattern comprising silicon and germanium
A vertical semiconductor device may include a substrate, a pattern structure on the substrate, and a channel structure in a channel hole passing through the pattern structure. The pattern structure may include insulation patterns and gate structures alternately stacked in a vertical direction perpendicular to an upper surface of the substrate. The channel structure may extend in the vertical direction. The channel structure may include a data storage structure on an inner surface of the channel hole, a channel contacting the data storage structure, a lower pattern on the channel positioned at a lower portion of the channel hole, and a filling insulation pattern on the channel and the lower pattern. The channel may have a cylindrical shape. The lower pattern may include an oxide including silicon and germanium.
1 . A semiconductor device, comprising:
a substrate;
a pattern structure on the substrate, the pattern structure including insulation patterns and gate structures alternately stacked in a vertical direction perpendicular to an upper surface of the substrate; and
a channel structure in a channel hole passing through the pattern structure, and the channel structure extending in the vertical direction,
wherein the channel structure includes
a data storage structure on an inner surface of the channel hole,
a channel contacting the data storage structure, and having a cylindrical shape,
a lower pattern on a bottom surface of the channel positioned at a lower portion of the channel hole, the lower pattern including an oxide including silicon and germanium, and
a filling insulation pattern on the channel and the lower pattern.
2 . The semiconductor device of claim 1 , wherein the channel includes polysilicon containing germanium.
3 . The semiconductor device of claim 2 , wherein
the channel includes a first portion and a second portion,
the first portion of the channel is positioned higher than an upper surface of the lower pattern,
the second portion of the channel is positioned lower than the upper surface of the lower pattern, and
a thickness of the first portion is less than a thickness of the second portion.
4 . The semiconductor device of claim 2 , wherein the channel has a uniform thickness depending on positions.
5 . The semiconductor device of claim 1 , wherein the channel structure further includes a first mask pattern between the channel and the lower pattern.
6 . The semiconductor device of claim 5 , wherein the first mask pattern includes silicon nitride, silicon oxide, titanium nitride, or aluminum oxide.
7 . The semiconductor device of claim 5 ,
wherein the first mask pattern includes pin holes.
8 . The semiconductor device of claim 1 , wherein the filling insulation pattern includes silicon oxide.
9 . The semiconductor device of claim 1 , wherein the channel has a grain size greater than 20 nm.
10 . A semiconductor device, comprising:
a substrate;
a pattern structure on the substrate, the pattern structure including insulation patterns and gate structures alternately stacked in a vertical direction perpendicular to an upper surface of the substrate; and
a channel structure in a channel hole passing through the pattern structure, and the channel structure extending in the vertical direction,
wherein the channel structure includes
a data storage structure on a sidewall of the channel hole,
a channel contacting the data storage structure, the channel having a cylindrical shape, and the channel including polysilicon containing germanium,
a lower pattern on the channel and positioned at a lower portion of the channel hole,
a first mask pattern between the channel and the lower pattern, and
a filling insulation pattern on the channel and the lower pattern, the filling insulation pattern including silicon oxide.
11 . The semiconductor device of claim 10 , wherein the lower pattern includes an oxide including silicon and germanium.
12 . The semiconductor device of claim 10 , wherein
the channel includes a first portion and a second portion,
the first portion of the channel is positioned higher than an upper surface of the lower pattern,
the second portion of the channel is positioned lower than the upper surface of the lower pattern, and
a thickness of the first portion is less than a thickness of the second portion.
13 . The semiconductor device of claim 10 , further comprising:
a common source plate on the substrate; and
a channel connection pattern on the common source plate, the channel connection pattern contacting an upper surface of the common source plate and a lower outer wall of the channel.
14 . The semiconductor device of claim 10 , further comprising:
a semiconductor pattern in a lower portion of the channel hole, wherein
the semiconductor pattern contacts the substrate, and
the channel structure is on the semiconductor pattern.
15 . The semiconductor device of claim 10 , wherein the first mask pattern includes silicon nitride, silicon oxide, titanium nitride, or aluminum oxide.