Semiconductor device having hybrid capacitors
11626405 · 2023-04-11
Assignee
Inventors
Cpc classification
H10B12/30
ELECTRICITY
H01L28/82
ELECTRICITY
International classification
H01L27/08
ELECTRICITY
Abstract
A semiconductor device includes a plurality of lower electrode structures disposed on a substrate, and a supporter pattern disposed between pairs of lower electrode structures of the plurality of lower electrode structures. The semiconductor device further includes a capacitor dielectric layer disposed on surfaces of each of the plurality of lower electrode structures and the supporter pattern, and an upper electrode disposed on the capacitor dielectric layer. The plurality of lower electrode structures includes a first lower electrode and a second lower electrode disposed on the first lower electrode and having a cylindrical shape. The first lower electrode has a pillar shape. The first lower electrode includes an insulating core. The insulating core is disposed in the first lower electrode. An outer side surface of the first lower electrode and an outer side surface of the second lower electrode are coplanar.
Claims
1. A semiconductor device comprising: a substrate; a plurality of lower electrode structures disposed on the substrate, each of the plurality of lower electrode structures including a first lower electrode and a second lower electrode that is disposed on the first lower electrode; a capacitor dielectric layer disposed on the plurality of lower electrode structures; and an upper electrode disposed on the capacitor dielectric layer, wherein the first lower electrode includes a lower portion having a pillar shape and an upper portion continuously extending from a first region of the lower portion in a vertical direction, a filling pattern is on and in contact with a second region of the lower portion of the first lower electrode, the second lower electrode includes a recess that is adjacent to a top surface of the second lower electrode, a bottom surface of the second lower electrode contacts a top surface of the filling pattern and a top surface of the upper portion of the first lower electrode, a portion of the capacitor dielectric layer and a portion of the upper electrode are disposed in the recess of the second lower electrode, the vertical direction is perpendicular to an upper surface of the substrate, the upper portion of the first lower electrode has an inner side surface contacting a side surface of the filling pattern and an outer side surface contacting the capacitor dielectric layer, and a first distance between a bottom surface of the lower portion of the first lower electrode and a bottom surface of the filling pattern is greater than a second distance between the inner side surface of the upper portion of the first lower electrode and an external side surface of the upper portion of the first lower electrode.
2. The semiconductor device of claim 1, wherein the top surface of the upper portion of the first lower electrode is substantially coplanar with the top surface of the filling pattern.
3. The semiconductor device of claim 1, wherein a bottom surface of the filling pattern is closer to the top surface of the upper portion of the first lower electrode than to a bottom surface of the lower portion of the first lower electrode.
4. The semiconductor device of claim 1, wherein the filling pattern includes amorphous silicon, amorphous carbon layer (ACL) and/or silicon oxide.
5. The semiconductor device of claim 1, wherein a diameter of the bottom surface of the second lower electrode is about 50 nm or less.
6. The semiconductor device of claim 1, wherein the second lower electrode includes a protruding portion that is disposed on an inner bottom surface of the second lower electrode and on the filling pattern.
7. The semiconductor device of claim 1, wherein the top surface of the filling pattern is higher than the top surface of the upper portion of the first lower electrode.
8. The semiconductor device of claim 1, wherein the second lower electrode includes a protrusion portion that is disposed on an outer bottom surface of the second lower electrode and on the filling pattern, and the protrusion portion of the second lower electrode extends in a hole defining by the upper portion of the first lower electrode.
9. The semiconductor device of claim 1, wherein the top surface of the filling pattern is lower than the top surface of the upper portion of the first lower electrode.
10. The semiconductor device of claim 1, wherein at least one of the top surface of the first lower electrode, the bottom surface of the second lower electrode and the top surface of the filling pattern are concave.
11. The semiconductor device of claim 1, wherein a width of the top surface of the filling pattern is greater than a width of a bottom surface of the filling pattern.
12. The semiconductor device of claim 1, wherein an outer side surface of the first lower electrode is substantially coplanar with an outer side surface of the second lower electrode.
13. The semiconductor device of claim 1, further comprising a first supporter contacting the first lower electrode and including a first opening that exposes at least three of the plurality of lower electrode structures, wherein a top surface of the first supporter is substantially coplanar with at least one of the top surface of the first lower electrode and the top surface of the filling pattern.
14. The semiconductor device of claim 13, further comprising a second supporter that is disposed on the first supporter, that contacts the second lower electrode and that includes a second opening which exposes at least three of the plurality of lower electrode structures, wherein a top surface of the second supporter is substantially coplanar with the top surface of the second lower electrode.
15. The semiconductor device of claim 1, wherein the capacitor dielectric layer doses not contact the filling pattern.
16. The semiconductor device of claim 1, wherein the filling pattern includes an insulating material.
17. A semiconductor device comprising: a substrate; a plurality of lower electrode structures disposed on the substrate, each of the plurality of lower electrode structures including a first lower electrode and a second lower electrode that is disposed on the first lower electrode; a first supporter disposed on the substrate and contacting the first lower electrode; a second supporter disposed on the first supporter and contacting the second lower electrode; a capacitor dielectric layer disposed on the plurality of lower electrode structures; and an upper electrode disposed on the capacitor dielectric layer, wherein the first lower electrode includes a lower portion having a pillar shape and an upper portion continuously extending from a first region of the lower portion in a vertical direction, a filling pattern is on and in contact with a second region of the lower portion of the first lower electrode, the second lower electrode includes a recess that is adjacent to a top surface of the second lower electrode, a bottom surface of the second lower electrode contacts a top surface of the filling pattern and a top surface of the upper portion of the first lower electrode, a portion of the capacitor dielectric layer and a portion of the upper electrode are disposed in the recess of the second lower electrode, the top surface of the upper portion of the first lower electrode is substantially coplanar with at least one of a top surface of the first supporter and the top surface of the filling pattern, the top surface of the second lower electrode is substantially coplanar with a top surface of the second supporter, the vertical direction is perpendicular to an upper surface of the substrate, the upper portion of the first lower electrode has an inner side surface contacting a side surface of the filling pattern and an outer side surface contacting the capacitor dielectric layer, and a first distance between a bottom surface of the lower portion of the first lower electrode and a bottom surface of the filling pattern is greater than a second distance between the inner side surface of the upper portion of the first lower electrode and the outer side surface of the upper portion of the first lower electrode.
18. The semiconductor device of claim 17, wherein a bottom surface of the filling pattern is closer to the top surface of the upper portion of the first lower electrode than to a bottom surface of the lower portion of the first lower electrode.
19. The semiconductor device of claim 17, wherein the filling pattern includes an insulating material.
20. A semiconductor device comprising: a substrate; a lower insulating layer disposed on the substrate and including a through hole; a contact plug disposed in the through hole of the lower insulating layer; an upper insulating layer disposed on the lower insulating layer; a lower electrode structure passing through the upper insulating layer and contacting the contact plug, the lower electrode structure including a first lower electrode and a second lower electrode that is disposed on the first lower electrode; a first supporter disposed on the substrate and contacting the first lower electrode; a second supporter disposed on the first supporter and contacting the second lower electrode; a capacitor dielectric layer disposed on the lower electrode structure; and an upper electrode disposed on the capacitor dielectric layer, wherein the first lower electrode includes a lower portion having a pillar shape and an upper portion continuously extending from a first region of the lower portion in a vertical direction, a filling pattern is on and in contact with a second region of the lower portion of the first lower electrode and includes an insulating material, the second lower electrode includes a recess that is adjacent to a top surface of the second lower electrode, a bottom surface of the second lower electrode contacts a top surface of the filling pattern and a top surface of the first lower electrode, a portion of the capacitor dielectric layer and a portion of the upper electrode are disposed in the recess of the second lower electrode, the top surface of the first lower electrode is substantially coplanar with a top surface of the first supporter and the top surface of the filling pattern, the filling pattern does not contact the capacitor dielectric layer, the vertical direction is perpendicular to an upper surface of the substrate, the upper portion of the first lower electrode has an inner side surface contacting a side surface of the filling pattern and an outer side surface contacting the capacitor dielectric layer, and a first distance between a bottom surface of the lower portion of the first lower electrode and a bottom surface of the filling pattern is greater than a second distance between the inner side surface of the upper portion of the first lower electrode and the outer side surface of the upper portion of the first lower electrode.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) A more complete appreciation of the present disclosure and many of the attendant aspects thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing, wherein:
(2)
(3)
(4)
(5)
(6)
DETAILED DESCRIPTION OF THE EMBODIMENTS
(7) Exemplary embodiments of the present inventive concept will be described more fully hereinafter with reference to the accompanying drawings.
(8)
(9) Referring to
(10) The substrate 102 may include a semiconductor material. For example, the substrate 102 may be a silicon substrate, a germanium substrate, a silicon germanium substrate, or a silicon-on-insulator (SOI) substrate. A plurality of word lines and bit lines which cross each other may be disposed on the substrate 102, and impurity regions may be disposed on the substrate 102.
(11) The contact plug 104 and the lower insulating layer 106 may be disposed on the substrate 102. The contact plug 104 may be disposed (e.g., buried) in the lower insulating layer 106 and a plurality of contact plugs 104 may be provided. For example, the contact plug 104 may be at least partially surrounded by the insulating layer 106. An upper surface of the contact plug 104 may be positioned at the same level as an upper surface of the lower insulating layer 106. For example, the upper surface of the contact plug 104 and the upper surface of the lower insulating layer 106 may be coplanar. However, the present inventive concept is not limited thereto. In an exemplary embodiment of the present inventive concept, the upper surface of the contact plug 104 may be positioned at a lower level than the upper surface of the lower insulating layer 106. A width of the contact plug 104 may be smaller than or equal to a width of a lower surface of a first lower electrode 122. The contact plug 104 may be electrically connected to the first lower electrode 122. The lower insulating layer 106 may insulate the contact plugs 104 from each other to prevent the plurality of contact plugs 104 from being electrically connected to each other.
(12) The contact plug 104 may include a conductive material. For example, the contact plug 104 may include a doped semiconductor material such as doped polysilicon, a metal-semiconductor compound such as WSi.sub.2, a metal nitride such as TiN or TaN, or a metal such as Ti, W, or Ta. The lower insulating layer 106 may include silicon oxide, silicon nitride, silicon oxynitride, or a combination thereof.
(13) The etch stop film 110 may be disposed on the lower insulating layer 106. The etch stop film 110 may prevent a plurality of first lower electrodes 122 from being electrically connected to each other. The etch stop film 110 may include silicon nitride, silicon oxynitride, or a combination thereof. Further, the etch stop film 110 may prevent a wet etchant from flowing to the lower insulating layer 106 during a wet etching process, thereby preventing the lower insulating layer 106 from being etched.
(14) A plurality of lower electrode structures 120 may be disposed on the contact plugs 104. Referring to
(15) In this specification, the first direction D1 refers to a direction which extends parallel to a main surface of the substrate 102 and in which the lower electrode structures 120 shown in
(16) Each lower electrode structure 120 may include the first lower electrode 122 and a second lower electrode 124 disposed on the first lower electrode 122. A lower electrode structure 120 may have a hybrid form including electrodes of different shapes. For example, the first lower electrode 122 may have a pillar shape and the second lower electrode 124 may have a cylindrical shape. The first lower electrode 122 and the second lower electrode 124 might not be misaligned. In other words, the first lower electrode 122 and the second lower electrode 124 may be aligned. For example, an outer side surface of the first lower electrode 122 and an outer side surface of the second lower electrode 124 may be positioned to be coplanar.
(17) The first lower electrode 122 may be disposed on the contact plug 104. The first lower electrode 122 may have a pillar shape and the outer side surface thereof may be covered by the capacitor dielectric layer 150. The first lower electrode 122 may include the insulating core 130 disposed therein. The second lower electrode 124 may be disposed on the first lower electrode 122. The second lower electrode 124 may have a cylindrical shape, and the outer side surface and an inner side surface of the second lower electrode 124 may be covered by the capacitor dielectric layer 150. In
(18) The first lower electrode 122 and the second lower electrode 124 may be electrically connected to the contact plug 104 and may include a metal, such as Ti, W, Ni, or Co, or a metal nitride, such as TiN, TiSiN, TiAlN, TaN, TaSiN, WN, and/or the like. In an exemplary embodiment of the present inventive concept, the first lower electrode 122 and the second lower electrode 124 may include TiN.
(19) The insulating core 130 may be disposed in an inside of the first lower electrode 122. The insulating core 130 may be positioned at a central portion of the first lower electrode 122 having, for example, a circular shape when viewed from above. However, the present inventive concept is not limited thereto. For example, the insulating core 130 may have a rectangular shape. The insulating core 130 may have a predetermined height, an upper end of the insulating core 130 may be in contact with a lower surface of the second lower electrode 124, and a lower end of the insulating core 130 may be positioned at a higher level than the lower surface of the first lower electrode 122. In
(20) The first supporter pattern 140 and the second supporter pattern 142 may be disposed between the lower electrode structures 120. The first supporter pattern 140 and the second supporter pattern 142 may connect the lower electrode structures 120 to each other. For example, the first supporter pattern 140 and the second supporter pattern 142 may provide support to the lower electrode structures 120. For example, the first supporter pattern 140 may support the first lower electrodes 122, and the second supporter pattern 142 may support the second lower electrodes 124. A thickness of the second supporter pattern 142 in the third direction D3 may be greater than a thickness of the first supporter pattern 140 in the third direction D3. The first supporter pattern 140 and the second supporter pattern 142 may have the same shape when viewed from above. In an exemplary embodiment of the present inventive concept, a side surface of the first supporter pattern 140, which is in contact with the first lower electrode 122, and a side surface of the second supporter pattern 142, which is in contact with the second lower electrode 124, may be coplanar.
(21) As shown in
(22) The capacitor dielectric layer 150 may be disposed between the lower electrode structure 120 and the upper electrode 160. For example, the capacitor dielectric layer 150 may be conformally disposed on surfaces of the etch stop film 110, the lower electrode structure 120, the first supporter pattern 140, and the second supporter pattern 142. For example, the capacitor dielectric layer 150 may include a metal oxide, such as HfO.sub.2, ZrO.sub.2, Al.sub.2O.sub.3, La.sub.2O.sub.3, Ta.sub.2O.sub.3, or TiO.sub.2, a dielectric material having a perovskite structure, such as SrTiO.sub.3 (STO), BaTiO.sub.3, lead zirconate titanate (PZT), or lanthanum-doped lead zirconate titanate (PLZT), or a combination thereof.
(23) The upper electrode 160 may be disposed on the capacitor dielectric layer 150. For example, the upper electrode 160 may include a metal, such as Ti, W, Ni, or Co, or a metal nitride, such as TiN, TiSiN, TiAlN, TaN, TaSiN, WN, and/or the like. In an exemplary embodiment of the present inventive concept, like the first lower electrode 122 and the second lower electrode 124, the upper electrode 160 may include TiN. The first lower electrode 122, the second lower electrode 124, the capacitor dielectric layer 150, and the upper electrode 160 may function as capacitors.
(24)
(25) Referring to
(26) The etch stop film 110 may include a material having an etch selectivity with respect to the first mold layer 125 and the second mold layer 126. For example, the etch stop film 110 may include silicon nitride, silicon oxynitride, or a combination thereof.
(27) The first mold layer 125 and the second mold layer 126 may include a material having an etch selectivity with respect to the first supporter layer 140a and the second supporter layer 142a. For example, the first mold layer 125 and the second mold layer 126 may include silicon oxide. For example, the first supporter layer 140a and the second supporter layer 142a may include silicon nitride. In an exemplary embodiment of the present inventive concept, a thickness of the second supporter layer 142a may be greater than a thickness of the first supporter layer 140a. However, the present inventive concept is not limited thereto.
(28) A portion of the second supporter layer 142a may be exposed by the first mask pattern 170 and the second mask pattern 172. A region in which a lower electrode structure 120 is disposed may be formed by the first mask pattern 170 and the second mask pattern 172. For example, the first mask pattern 170 may include amorphous carbon and/or polysilicon, and the second mask pattern 172 may include a photosensitive material.
(29) Referring to
(30) Referring to
(31) Referring to
(32) After the insulating core 131 fills the seam S, a planarization process may be performed. The second mask pattern 172 may be removed by the planarization process. An upper surface of the first conductive layer 121 may be positioned at substantially the same level as an upper end of the insulating core 131. In an exemplary embodiment of the present inventive concept, the planarization process may be omitted. For example, the insulating core 131 may include an insulating material, such as amorphous silicon, an ACL, and/or silicon oxide (SiO.sub.2).
(33) Referring to
(34) In
(35) Referring to
(36) Referring to
(37) Referring to
(38) For example, the capacitor dielectric layer 150 may include a metal oxide, such as HfO.sub.2, ZrO.sub.2, Al.sub.2O.sub.3, La.sub.2O.sub.3, Ta.sub.2O.sub.3, or TiO.sub.2, a dielectric material of a perovskite structure, such as STO, BaTiO.sub.3, PZT, or PLZT, or a combination thereof. The capacitor dielectric layer 150 may be formed by a process such as a CVD process, an ALD process, or the like.
(39) Referring to
(40) The upper electrode 160 may include the same material as that of the first lower electrode 122 and the second lower electrode 124. For example, the upper electrode 160 may include TiN. The upper electrode 160 may be formed by a process such as a CVD process, an ALD process, or the like.
(41) As shown in
(42) As shown in
(43)
(44) Referring to
(45) The second lower electrode 224 having a cylindrical shape may include a protrusion 225 protruding upward from an inner lower surface 224a thereof. Correspondingly, an outer lower surface 224b of the second lower electrode 224 may have a concave shape in an upward direction. The protrusion 225 may overlap the insulating core 230. For example, the protrusion 225 may be positioned on the insulating core 230. As shown in
(46) Referring to
(47) The second lower electrode 324 may include a protrusion 325 protruding downward from an outer lower surface 324b thereof. Correspondingly, an inner lower surface 324a of the second lower electrode 324 may have a concave shape extending downward. The protrusion 325 may be positioned on the insulating core 330. The capacitor dielectric layer 350 may be conformally formed along surfaces of the etch stop film 110, the first lower electrode 322, the second lower electrode 324, the first supporter pattern 140, and the second supporter pattern 142. A portion of the capacitor dielectric layer 350, which is disposed in the second lower electrode 324, may be formed to have a convex shape in a downward direction. For example, the capacitor dielectric layer 350 may have a protrusion corresponding to the protrusion 325 of the outer lower surface 324b.
(48) Referring to
(49) Referring to
(50)
(51) Referring to
(52) Referring to
(53) Referring to
(54) Referring to
(55) Referring to
(56) Referring to
(57) According to an exemplary embodiment of the present inventive concept, in a semiconductor device, an insulating core is formed inside a first lower electrode disposed below a second lower electrode, and thus, exposure of a contact plug can be prevented during an etching process and leakage current and degradation of capacitors can be prevented.
(58) Exemplary embodiments of the present inventive concept are directed to a semiconductor device for preventing leakage current and degradation of capacitors.
(59) While the present inventive concept has been described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made thereto without departing from the spirit and scope of the present inventive concept.