Semiconductor device having a channel pattern and method of manufacturing the same
A semiconductor device may include a tubular channel pattern vertically extending from a semiconductor substrate. A gate insulation layer may be provided on faces exposed through the channel pattern. A gate electrode may be provided on the gate insulation layer. The gate electrode may fill the channel pattern. A conductive region, which may serve as lower source/drain regions, may be formed at a surface portion of the semiconductor substrate. The conductive region may contact a lower portion of the channel pattern. A conductive pattern, which may serve as upper source/drain regions, may horizontally extend from an upper portion of the channel pattern.
1. A semiconductor device, comprising:
a tubular channel pattern vertically extending from a semiconductor substrate;
a gate insulation layer provided on an inner sidewall of the channel pattern and a portion of the semiconductor substrate exposed through the channel pattern so as to form a closed bottom portion;
a gate electrode provided on the gate insulation layer;
a conductive region provided at a surface portion of the substrate, the conductive region contacting the channel pattern; and
a conductive pattern vertically spaced apart from the conductive region and horizontally extending from the channel pattern.
2. The semiconductor device of claim 1 , wherein the substrate comprises any one selected from the group consisting of a bulk silicon wafer and a silicon-on-insulator semiconductor substrate.
3. The semiconductor device of claim 1 , wherein the gate electrode comprises any one material selected from the group consisting of polysilicon doped with impurities and a metal.
4. The semiconductor device of claim 1 , wherein the gate electrode comprises a polysilicon pattern doped with impurities and a metal silicide pattern formed on the polysilicon pattern.
5. The semiconductor device of claim 1 , wherein the conductive pattern comprises any one material selected from the group consisting of polysilicon doped with impurities and a metal.
6. The semiconductor device of claim 1 , wherein the gate insulation layer comprises at least one material selected from the group consisting of silicon oxide, silicon oxynitride, hafnium oxide, zirconium oxide, lanthanum oxide, tantalum oxide, titanium oxide, strontium titanate and barium strontium titanate.
7. The semiconductor device of claim 1 , wherein the gate insulation layer has an upper face higher than that of the channel pattern, and the gate electrode having an upper face higher than that of the gate insulation layer.
8. The semiconductor device of claim 7 , wherein the conductive pattern horizontally extends from the gate insulation layer.
9. The semiconductor device of claim 8 , further comprising an insulating interlayer provided on the conductive pattern, the insulating interlayer having an upper face lower than that of the gate electrode.
10. The semiconductor device of claim 8 , further comprising an insulating interlayer provided on the conductive pattern, wherein the gate electrode comprises a polysilicon plug extending to an upper face of the insulating interlayer and a metal pattern formed on the polysilicon plug.
11. The semiconductor device of claim 1 , wherein the conductive region and the conductive pattern extend in horizontal directions substantially different from each other.
12. The semiconductor device of claim 1 , wherein the conductive region and the conductive pattern extend in horizontal directions substantially identical to each other, and the conductive region has an extension length longer than that of the conductive pattern.
13. The semiconductor device of claim 1 , wherein the channel pattern has a circular tubular shape and the gate electrode has a cylindrical shape.
14. The semiconductor device of claim 1 , wherein the conductive pattern encloses a portion of the channel pattern.
15. A method, comprising:
forming a tubular channel pattern that vertically extends from a substrate;
forming a conductive region at a surface portion of the substrate, the conductive region contacting the channel pattern;
forming a conductive pattern that is vertically spaced apart from the conductive region and horizontally extends from the channel pattern;
forming a gate insulation layer on an inner sidewall of the channel pattern and a portion of the semiconductor substrate exposed through the channel pattern so as to form a closed bottom portion; and
forming a gate electrode on the gate insulation layer.
16. The method of claim 15 , wherein forming the channel pattern comprises:
forming a sacrificial plug that includes first and second portions, the first portion being protruded from the substrate, and the second portion being buried in the substrate;
forming a sacrificial spacer on a sidewall of the sacrificial plug; and
anisotropically etching the substrate using the sacrificial plug and the sacrificial spacer as etching masks to form the channel pattern.
17. The method of claim 16 , wherein forming the sacrificial plug comprises:
forming a first sacrificial layer that includes a first opening partially exposing the substrate;
anisotropically etching an exposed portion of the substrate to form a second opening exposing the substrate;
forming a second sacrificial layer on the first sacrificial layer to fill up the first and the second openings;
partially removing an upper portion of the second sacrificial layer until the first sacrificial layer is exposed; and
removing the first sacrificial layer.
18. The method of claim 16 , wherein forming the conductive region comprises:
implanting impurities into a portion of the substrate adjacent to the channel pattern to form a preliminary conductive region; and
patterning the preliminary conductive region.
19. The method of claim 18 , wherein the conductive region extends in a first direction and the conductive pattern extends in a second direction substantially different from the first direction.
20. The method of claim 18 , wherein the conductive region and the conductive pattern extend in parallel directions substantially identical to each other, and the conductive region has an extension length substantially longer than that of the conductive pattern.
21. The method of claim 16 , wherein forming the conductive pattern comprises:
forming an insulation layer on the substrate, the channel pattern being partially protruded from the insulation layer;
forming a conductive layer on the sacrificial plug, the channel pattern and the insulation layer;
planarizing the conductive layer to expose the sacrificial plug;
patterning the planarized conductive layer to form a preliminary conductive pattern; and
partially removing the preliminary conductive pattern until a portion of the sacrificial plug protrudes from the conductive pattern.
22. The method of claim 21 , wherein the conductive pattern contacts a side face of the sacrificial plug.
23. The method of claim 22 , wherein forming the gate insulation layer comprises:
forming an insulating interlayer on the conductive pattern and the sacrificial plug;
planarizing the insulating interlayer until the sacrificial plug is exposed;
removing the sacrificial plug to form an opening exposing the inner sidewall of the channel pattern and the portion of the substrate; and
forming the gate insulation layer on the conductive pattern, the inner sidewall of the channel pattern and the portion of the substrate exposed through the opening.
24. The method of claim 23 , wherein forming the gate electrode comprises:
forming a second conductive layer on the gate insulation layer and the insulating interlayer to fill the opening; and
patterning the conductive layer.
25. The method of claim 23 , forming the gate electrode comprises:
forming a polysilicon layer on the gate insulation layer and the insulating interlayer to fill the opening;
forming a metal suicide layer on the polysilicon layer; and
patterning the polysilicon layer and the metal suicide layer.
26. The method of claim 23 , wherein forming the gate electrode comprises:
forming a polysilicon layer on the gate insulation layer and the insulating interlayer to fill the opening;
removing an upper portion of the polysilicon layer until the insulating interlayer is exposed to form a polysilicon plug in the opening;
forming a metal layer on the polysilicon plug and the insulating interlayer; and
patterning the metal layer.
27. A semiconductor device, comprising:
a channel pattern vertically extending from a semiconductor substrate, wherein the channel pattern has a tubular shape;
a gate insulation layer provided on a sidewall of the channel pattern and the semiconductor substrate so as to form a closed bottom portion;
a gate electrode provided on the gate insulation layer;
a conductive region provided at a surface portion of the substrate, the conductive region contacting the channel pattern; and
a conductive pattern vertically spaced apart from the conductive region and horizontally extending from the channel pattern.
28. A method, comprising:
forming a channel pattern that vertically extends from a substrate, wherein the channel pattern has a tubular shape;
forming a conductive region at a surface portion of the substrate, the conductive region contacting the channel pattern;
forming a conductive pattern that is vertically spaced apart from the conductive region and horizontally extends from the channel pattern;
forming a gate insulation layer on the channel pattern and the semiconductor substrate so as to form a closed bottom portion; and
forming a gate electrode on the gate insulation layer.