阅读说明：本技术 半导体器件
(Semiconductor device with a plurality of transistors
) 是由 朴桭胡
丁少锋
方镛胜
安正勋 于 2020-04-15 设计创作，主要内容包括：本公开提供了半导体器件。一种半导体器件包括：基板；第一电极,包括第一孔；第一电介质层,在第一电极的上表面上和在第一孔的内表面上；第二电极,在第一电介质层上；第二电介质层,在第二电极上；第三电极,在第二电介质层上并包括第二孔；以及第一接触插塞,延伸穿过第二电极和第二电介质层并延伸穿过第一孔和第二孔。第一接触插塞的侧壁脱离与第一孔的侧壁和第二孔的侧壁的直接接触,并具有与第二电极的上表面相邻定位的台阶部分。(The present disclosure provides a semiconductor device. A semiconductor device includes: a substrate; a first electrode including a first hole; a first dielectric layer on an upper surface of the first electrode and on an inner surface of the first hole; a second electrode on the first dielectric layer; a second dielectric layer on the second electrode; a third electrode on the second dielectric layer and including a second hole; and a first contact plug extending through the second electrode and the second dielectric layer and extending through the first hole and the second hole. The sidewall of the first contact plug is out of direct contact with the sidewall of the first hole and the sidewall of the second hole, and has a step portion positioned adjacent to the upper surface of the second electrode.)
1. A semiconductor device, comprising:
a substrate;
a first electrode including a first hole;
a first dielectric layer on an upper surface of the first electrode and filling at least a portion of the first hole;
a second electrode on the first dielectric layer;
a second dielectric layer on the second electrode;
a third electrode on the second dielectric layer, the third electrode comprising a second hole; and
a first contact plug extending through the first hole, the second electrode, the second dielectric layer, and the second hole,
wherein a sidewall of the first contact plug is out of direct contact with the first electrode and the third electrode, the sidewall of the first contact plug has a step portion, and the step portion of the sidewall of the first contact plug is adjacent to an upper surface of the second electrode.
2. The semiconductor device according to claim 1, wherein the step portion of the sidewall of the first contact plug is between a portion of the upper surface of the second electrode covered with the second dielectric layer and a lower surface of the second electrode.
3. The semiconductor device according to claim 1, wherein the step portion of the side wall of the first contact plug contacts a portion of the upper surface of the second electrode.
4. The semiconductor device of claim 1, further comprising:
a second contact plug extending through the first electrode, the first dielectric layer, the second dielectric layer, and the third electrode, the second contact plug contacting the first electrode and the third electrode, the second contact plug being out of direct contact with the second electrode,
wherein a sidewall of the second contact plug has a plurality of step portions.
5. The semiconductor device of claim 1, further comprising:
a second contact plug extending through the first electrode, the first dielectric layer, the second dielectric layer, and the third electrode, the second contact plug contacting the first electrode and the third electrode, the second contact plug being out of direct contact with the second electrode,
wherein the second contact plug covers a portion of the upper surface of the first electrode and a portion of an upper surface of the third electrode.
6. The semiconductor device of claim 1, further comprising:
a second contact plug extending through the first electrode, the first dielectric layer, the second dielectric layer, and the third electrode, the second contact plug contacting the first electrode and the third electrode, the second contact plug being out of direct contact with the second electrode,
wherein the second contact plug comprises
A first portion between the upper surface of the first electrode and an upper surface of the substrate,
a second portion at least partially remote from an upper surface of the substrate relative to the upper surface of the third electrode, an
A third portion between the first portion and the second portion, and
wherein the sidewalls of the first portion, the second portion, and the third portion are aligned with one another to define separate portions of a single continuous three-dimensional geometric shaped surface.
7. The semiconductor device of claim 1, wherein
The first contact plug includes
A first portion at least partially distal from an upper surface of the substrate relative to the upper surface of the second electrode; and
a second portion at least partially between a lower surface of the second electrode and the upper surface of the substrate,
the width of the first portion continuously decreases in proportion to getting closer to the second electrode, and
the width of the second portion continuously decreases in proportion to getting closer to the upper surface of the substrate.
8. The semiconductor device of claim 1, further comprising:
an interlayer insulating layer between the upper surface of the substrate and the first electrode;
a lower wiring layer between the interlayer insulating layer and the upper surface of the substrate; and
a second contact plug extending through the interlayer insulating layer, the first dielectric layer, and the second dielectric layer, the second contact plug contacting the lower wiring layer,
wherein the first electrode is on and in contact with an upper surface of the interlayer insulating layer, and
a portion of the first dielectric layer is on and in contact with a portion of the upper surface of the interlayer insulating layer.
9. A semiconductor device, comprising:
a substrate;
a first electrode on the substrate;
a first dielectric layer on the first electrode;
a second electrode on the first dielectric layer;
a second dielectric layer on the second electrode;
a third electrode on the second dielectric layer; and
a first contact plug extending through and contacting the first electrode and the third electrode,
wherein the first contact plug comprises
A first portion at least partially between a lower surface of the first electrode and an upper surface of the substrate,
a second portion at least partially remote from an upper surface of the substrate relative to the upper surface of the third electrode, an
A third portion at least partially between the upper surface of the first electrode and the lower surface of the third electrode,
wherein the sidewalls of the first portion are offset to the sidewalls of the third portion,
wherein the sidewalls of the third portion are offset to sidewalls of the second portion.
10. The semiconductor device of claim 9, wherein
The first contact plug is out of direct contact with the second electrode, and
the third portion of the first contact plug extends through both the first dielectric layer and the second dielectric layer.
11. The semiconductor device of claim 9, wherein
The second electrode comprises a hole, and the second electrode comprises a hole,
the second dielectric layer includes a first portion that fills a portion of the hole,
the third electrode includes a second portion that fills a remaining portion of the hole that is not filled by the first portion of the second dielectric layer, and
the third portion of the first contact plug extends through both the second portion of the third electrode and the first portion of the second dielectric layer.
12. The semiconductor device of claim 9, wherein
The second portion of the first contact plug covers a portion of the upper surface of the third electrode, and
the third portion of the first contact plug covers a portion of the upper surface of the first electrode.
13. The semiconductor device of claim 9, wherein
The width of the second portion of the first contact plug is greater than the width of the third portion of the first contact plug, and
the width of the third portion of the first contact plug is greater than the width of the first portion of the first contact plug.
14. The semiconductor device of claim 9, further comprising:
a second contact plug extending through the second electrode and contacting the second electrode.
15. The semiconductor device of claim 14, wherein
The second contact plug comprises
A first portion at least partially remote from an upper surface of the substrate relative to the upper surface of the second electrode, and
a second portion at least partially between a lower surface of the second electrode and the upper surface of the substrate, and
sidewalls of the first portion of the second contact plug are offset to sidewalls of the second portion of the second contact plug.
16. The semiconductor device of claim 14, wherein
The second contact plug is out of direct contact with the first electrode and the third electrode, and
the second contact plug extends through both the first dielectric layer and the second dielectric layer.
17. The semiconductor device of claim 14, wherein
The first electrode includes a first aperture and,
the third electrode includes a second hole vertically overlapping the first hole, and
the second contact plug extends through both the first hole and the second hole.
18. The semiconductor device of claim 17, wherein
The first dielectric layer includes a first portion that fills a portion of the first hole,
the second electrode includes a second portion that fills a remaining portion of the first hole that is not filled by the first portion of the first dielectric layer, and
the second contact plug extends through the first portion of the first dielectric layer and the second portion of the second electrode.
19. The semiconductor device of claim 14, wherein
The second contact plug comprises
A first portion at least partially remote from an upper surface of the substrate relative to the upper surface of the second electrode, and
a second portion at least partially between the upper surface of the second electrode and the upper surface of the substrate, and
sidewalls of the first portion of the second contact plug are aligned with sidewalls of the second portion of the second contact plug.
20. The semiconductor device of claim 9, further comprising:
an interlayer insulating layer between the upper surface of the substrate and the first electrode; and
a first lower wiring layer between the upper surface of the substrate and the interlayer insulating layer,
wherein the first contact plug extends through the interlayer insulating layer and contacts the first lower wiring layer.
21. A semiconductor device, comprising:
a substrate;
a first electrode on the substrate;
a first dielectric layer on the first electrode;
a second electrode on the first dielectric layer, the second electrode comprising a first aperture;
a second dielectric layer on the second electrode, the second dielectric layer at least partially filling the first hole;
a third electrode on the second dielectric layer; and
a first contact plug extending through the first electrode, the first dielectric layer, the first hole, and the third electrode,
wherein the first contact plug covers at least one of a portion of an upper surface of the first electrode and a portion of an upper surface of the third electrode.
22. The semiconductor device of claim 21, wherein a portion of the third electrode is between the second dielectric layer and the first contact plug and at least partially fills the first hole.
23. The semiconductor device of claim 21, wherein the second dielectric layer contacts an upper surface of the first dielectric layer.
24. The semiconductor device of claim 21, further comprising:
a second contact plug formed on the first contact plug,
wherein the first electrode comprises a second aperture,
wherein the third electrode includes a third hole vertically overlapping the second hole,
wherein the second contact plug extends through the second hole, the first dielectric layer, the second electrode, the second dielectric layer, and the third hole, and
wherein the second contact plug contacts the second electrode.
25. The semiconductor device of claim 24, wherein the first dielectric layer fills at least a portion of the second hole.
Technical Field
Example embodiments of the present disclosure relate to semiconductor devices, and more particularly, to metal-insulator-metal (MIM) capacitors.
Background
As the integration density of semiconductor devices, such as Dynamic Random Access Memory (DRAM) devices, increases, the area of a unit cell in a semiconductor device decreases, and thus the area of one or more capacitors in the semiconductor device also decreases. However, in order to integrate a semiconductor device, it may be desirable to increase the capacitance of the capacitor.
As the thickness of the capacitor dielectric layer of the capacitor is reduced to increase the capacitance of the capacitor, the leakage current of the capacitor may increase. Thus, the high dielectric layer may serve as a capacitor dielectric layer of the capacitor. However, when the high dielectric layer is used as a capacitor dielectric layer in a capacitor, a low dielectric layer may be formed between the high dielectric layer and the upper electrode in the case where the upper electrode of the capacitor is formed of polysilicon. As a result, a desired capacitance of the capacitor cannot be obtained. Accordingly, metal-insulator-metal (MIM) capacitors may be used in semiconductor devices instead of metal-insulator-semiconductor (MIS) capacitors.
Disclosure of Invention
According to some example embodiments of the inventive concepts, a semiconductor device may include: a substrate; a first electrode including a first hole; a first dielectric layer on an upper surface of the first electrode and filling at least a portion of the first hole; a second electrode on the first dielectric layer; a second dielectric layer on the second electrode; a third electrode on the second dielectric layer, the third electrode including a second hole; and a first contact plug extending through the first hole, the second electrode, the second dielectric layer, and the second hole. The sidewall of the first contact plug may be out of direct contact with the first electrode and the third electrode. The sidewall of the first contact plug may have a step portion. The step portion of the sidewall of the first contact plug may be adjacent to an upper surface of the second electrode.
According to some example embodiments of the inventive concepts, a semiconductor device may include: a substrate; a first electrode on the substrate; a first dielectric layer on the first electrode; a second electrode on the first dielectric layer; a second dielectric layer on the second electrode; a third electrode on the second dielectric layer; and a first contact plug extending through and contacting the first electrode and the third electrode. The first contact plug may include a first portion at least partially between the lower surface of the first electrode and the substrate, a second portion at least partially remote from the upper surface of the substrate relative to the upper surface of the third electrode, and a third portion at least partially between the upper surface of the first electrode and the lower surface of the third electrode. The sidewalls of the first portion may be offset to the sidewalls of the third portion. The sidewalls of the third portion may be offset to the sidewalls of the second portion.
According to some example embodiments of the inventive concepts, a semiconductor device may include: a substrate; a first electrode on the substrate; a first dielectric layer on the first electrode; a second electrode on the first dielectric layer, the second electrode including a first hole; a second dielectric layer on the second electrode, the second dielectric layer at least partially filling the first hole; a third electrode on the second dielectric layer; and a first contact plug extending through the first electrode, the first dielectric layer, the first hole, and the third electrode. The first contact plug may cover at least one of a portion of an upper surface of the first electrode and a portion of an upper surface of the third electrode.
Drawings
Fig. 1is a plan view illustrating a semiconductor device according to some example embodiments of the inventive concepts.
Fig. 2 is a cross-sectional view taken along line I-I' of fig. 1, illustrating a semiconductor device according to some example embodiments of the inventive concepts.
Fig. 3A is an enlarged view of a portion a of fig. 2.
Fig. 3B is an enlarged view of a portion B of fig. 2.
Fig. 4 is a cross-sectional view taken along line I-I' of fig. 1, illustrating a semiconductor device according to some example embodiments of the inventive concepts.
Fig. 5is a cross-sectional view taken along line I-I' of fig. 1, illustrating a semiconductor device according to some example embodiments of the inventive concepts.
Fig. 6 is a cross-sectional view taken along line I-I' of fig. 1, illustrating a semiconductor device according to some example embodiments of the inventive concepts.
Fig. 7A, 7B, 7C, 7D, 7E, 7F, and 7G illustrate methods of manufacturing a semiconductor device according to some example embodiments of the inventive concepts, and are sectional views taken along line I-I' of fig. 1.
Detailed Description
Various example embodiments will now be described more fully hereinafter with reference to the accompanying drawings. Throughout this application, like reference numerals may refer to like elements.
Fig. 1is a plan view illustrating a semiconductor device according to some example embodiments of the inventive concepts. Fig. 2 is a cross-sectional view taken along line I-I' of fig. 1, illustrating a semiconductor device according to some example embodiments of the inventive concepts. Fig. 3A is an enlarged view of a portion a of fig. 2. Fig. 3B is an enlarged view of a portion B of fig. 2.
Referring to fig. 1 and 2, a first interlayer insulating layer 101 may be disposed on an upper surface 100U of a substrate 100. The substrate 100 may be, for example, a silicon single crystal wafer or a silicon-on-insulator (SOI) substrate. The first interlayer insulating layer 101 may include an insulating material, for example, silicon oxide or silicon nitride. The first lower wiring layer 103 may be disposed in the first interlayer insulating layer 101. The upper surface of the first lower wiring layer 103 may be coplanar with the upper surface of the first interlayer insulating layer 101. The first lower wiring layer 103 may include a metal such as copper, aluminum, or tungsten. The first buffer insulating layer 105 may be disposed on an upper surface of the first interlayer insulating layer 101. The first buffer insulating layer 105 may cover a part of the upper surface of the first lower wiring layer 103 and the entire upper surface of the first interlayer insulating layer 101. The first buffer insulating layer 105 may include, for example, silicon carbon nitride (SiCN).
The second interlayer insulating layer 107 may be disposed on the first buffer insulating layer 105. The second interlayer insulating layer 107 may cover an upper surface of the first buffer insulating layer 105. The second interlayer insulating layer 107 may include an insulating material, for example, silicon oxide or silicon nitride. A second buffer insulating layer 109 may be disposed on the second interlayer insulating layer 107. The second buffer insulating layer 109 may cover an upper surface of the second interlayer insulating layer 107. The second buffer insulating layer 109 may include, for example, silicon carbon nitride (SiCN). The third interlayer insulating layer 111 may be disposed on the second buffer insulating layer 109. The third interlayer insulating layer 111 may cover an upper surface of the second buffer insulating layer 109. The third interlayer insulating layer 111 may include an insulating material, for example, silicon oxide or silicon nitride.
It will be understood that, as used herein, an element "on" another element can be above or below the other element. In addition, an element "on" another element may be directly on the other element such that the element is in direct contact with at least a portion of the other element, or may be indirectly on the other element such that the element is out of direct contact with the other element through one or more intervening structures and/or spaces (isolated from direct contact).
The second lower wiring layer 113 may be disposed in the second buffer insulating layer 109 and the third interlayer insulating layer 111. The second lower wiring layer 113 may penetrate the third interlayer insulating layer 111 and the second buffer insulating layer 109. The upper surface of the second lower wiring layer 113 may be coplanar with the upper surface of the third interlayer insulating layer 111. The second lower wiring layer 113 may include a metal, such as copper, aluminum, or tungsten. The third lower wiring layer 115 may be disposed in the third interlayer insulating layer 111 and the second buffer insulating layer 109. The third lower wiring layer 115 may penetrate the third interlayer insulating layer 111 and the second buffer insulating layer 109. The third lower wiring layer 115 may be spaced apart from the second lower wiring layer 113. The upper surface of the third lower wiring layer 115 may be coplanar with the upper surface of the third interlayer insulating layer 111. The third lower wiring layer 115 may include a metal such as copper, aluminum, or tungsten. The fourth lower wiring layer 117 may be disposed in the second buffer insulating layer 109 and the third interlayer insulating layer 111. The fourth lower wiring layer 117 may penetrate the third interlayer insulating layer 111 and the second buffer insulating layer 109. The fourth lower wiring layer 117 may be spaced apart from the second lower wiring layer 113 and the third lower wiring layer 115. The upper surface of the fourth lower wiring layer 117 may be coplanar with the upper surface of the third interlayer insulating layer 111. The fourth lower wiring layer 117 may be electrically connected to a resistor. The fourth lower wiring layer 117 may include a metal such as copper, aluminum, or tungsten. The conductive through via 119 may be provided between the first lower wiring layer 103 and the third lower wiring layer 115. The conductive through via 119 may penetrate the first buffer insulating layer 105 and the second interlayer insulating layer 107. The conductive through via 119 may contact the first lower wiring layer 103 and the third lower wiring layer 115 and may be electrically connected between the first lower wiring layer 103 and the third lower wiring layer 115. The conductive through vias 119 may comprise a metal, such as copper, aluminum, or tungsten.
The third buffer insulating layer 121 may be disposed on the third interlayer insulating layer 111. The third buffer insulating layer 121 may cover upper surfaces of the second to fourth lower wiring layers 113, 115, and 117 and an upper surface of the third interlayer insulating layer 111. The third buffer insulating layer 121 may include, for example, silicon carbon nitride (SiCN). A fourth interlayer insulating layer 123 may be disposed on the third buffer insulating layer 121. The thickness of the fourth interlayer insulating layer 123 may be greater than the thickness of each of the first to third interlayer insulating layers 101, 107, and 111. The fourth interlayer insulating layer 123 may include an insulating material, for example, silicon oxide or silicon nitride.
The first electrode 201 may be disposed on the upper surface 123U of the fourth interlayer insulating layer 123 and may contact the upper surface 123U of the fourth interlayer insulating layer 123 such that the first to fourth interlayer insulating layers 101, 107, 111, and 123 are between the upper surface 100U of the substrate 100 and the first electrode 201. The first electrode 201 may vertically overlap the second lower wiring layer 113 and the third lower wiring layer 115. The first electrodes 201 may not be provided on the fourth lower wiring layer 117 or may not vertically overlap with the fourth lower wiring layer 117. The first electrode 201 may include a first hole H1 therein. The first holes H1 may vertically overlap with the second lower wiring layer 113 (e.g., overlap in a vertical direction perpendicular to the upper surface 100U of the substrate 100). The first hole H1 may expose a portion of the upper surface of the fourth interlayer insulating layer 123. The first electrode 201 may include, for example, TaN, Ta, Al, Ti, TiN, TaSiN, WN, and/or WSiN.
A first dielectric layer 203 may be disposed on the first electrode 201. As shown in fig. 2 and 3A, the first dielectric layer 203 may be on the upper surface 201U and the sidewalls 201S of the first electrode 201 and may cover the upper surface 201U and the sidewalls 201S of the first electrode 201. The first dielectric layer 203 may be disposed on the bottom surface H1B and the sidewalls H1S of the first hole H1. That is, the first dielectric layer 203 may be on a portion of the upper surface 123U of the fourth interlayer insulating layer 123 exposed by the first hole H1,the portion may be contacted and thus may be covered. The first dielectric layer 203 may comprise, for example, Si3N4、Ta2O5、Al2O3And/or ZrO2. As shown in at least fig. 3A, the first dielectric layer 203 may include a portion that fills at least a portion of the first hole H1 (e.g., fills a limited portion of the first hole H1 such that the remainder of the first hole H1 is not filled by the first dielectric layer 203).
The second electrode 205 may be disposed on the first dielectric layer 203. The second electrode 205 may cover a portion of the upper surface of the first dielectric layer 203. The second electrode 205 may vertically overlap the second lower wiring layer 113 and the third lower wiring layer 115. The second electrode 205 may not be provided on the fourth lower wiring layer 117 or vertically overlap with the fourth lower wiring layer 117. The second electrode 205 may fill the first hole H1 of the first electrode 201 in which the first dielectric layer 203 is disposed. For example, as shown in fig. 3A, the second electrode 205 may include a portion that fills the remaining portion of the first hole H1 that is not filled by at least the portion of the first dielectric layer 203. The second electrode 205 may include a second hole H2 therein. The second hole H2 may vertically overlap the third lower wiring layer 115. The second hole H2 may expose a portion of the upper surface of the first dielectric layer 203. The second electrode 205 may include, for example, TaN, Ta, Al, Ti, TiN, TaSiN, WN, and/or WSiN.
A second dielectric layer 207 may be disposed on the second electrode 205. The second dielectric layer 207 may cover the upper surface and sidewalls of the second electrode 205. The second dielectric layer 207 may be disposed on the bottom surface H2B and the sidewalls H2S of the second hole H2. As shown in at least fig. 3B, the second dielectric layer 207 may include a portion that fills at least a portion of the second hole H2 (e.g., fills a limited portion of the second hole H2 such that the remainder of the second hole H2 is not filled by the second dielectric layer 207). The second dielectric layer 207 may cover a portion of the upper surface 203U of the first dielectric layer 203 exposed by the second hole H2. The second dielectric layer 207 may contact a portion of the upper surface 203U of the first dielectric layer 203 exposed by the second hole H2. The second dielectric layer 207 may contact the upper surface 203U of the first dielectric layer 203A portion above the fourth lower wiring layer 117. The second dielectric layer 207 may comprise, for example, Si3N4、Ta2O5、Al2O3And/or ZrO2。
A third electrode 209 may be disposed on the second dielectric layer 207. The third electrode 209 may cover an upper surface and sidewalls of the second dielectric layer 207. For example, as shown in fig. 3B, the third electrode 209 may include a portion that fills the remaining portion of the second hole H2 that is not filled by the portion of the second dielectric layer 207. The third electrode 209 may vertically overlap the second lower wiring layer 113 and the third lower wiring layer 115. The third electrode 209 may not be provided on the fourth lower wiring layer 117 or vertically overlap with the fourth lower wiring layer 117. The third electrode 209 may include a third hole H3 therein. As shown in fig. 3A, the third hole H3 may partially or completely vertically overlap with the first hole H1 of the first electrode 201 (e.g., partially or completely overlap in a direction perpendicular to the upper surface 100U of the substrate 100). The third hole H3 may expose a portion of the upper surface of the second dielectric layer 207. The third electrode 209 may fill the second hole H2 of the second electrode 205 in which the second dielectric layer 207 is disposed. The third electrode 209 may include, for example, TaN, Ta, Al, Ti, TiN, TaSiN, WN, and/or WSiN. A fifth interlayer insulating layer 211 may be disposed on the third electrode 209. The fifth interlayer insulating layer 211 may cover the third electrode 209 and the second dielectric layer 207. The fifth interlayer insulating layer 211 may fill the third hole H3. The fifth interlayer insulating layer 211 may include an insulating material, for example, silicon oxide or silicon nitride.
Referring to fig. 2 and 3A, the first contact plug CP1 may extend through (e.g., penetrate) the first hole H1 of the first electrode 201 and the third hole H3 of the third electrode 209. The first contact plug CP1 may extend through the fifth interlayer insulating layer 211, the second electrode 205, the first dielectric layer 203, the second dielectric layer 207, the fourth interlayer insulating layer 123, and the third buffer insulating layer 121. As shown in fig. 3A, the first contact plug CP1 may extend through a portion of the first dielectric layer 203 filling a portion of the first hole H1 and a portion of the second electrode 205 filling the remaining portion of the first hole H1 not filled by the first dielectric layer 203. The first contact plug CP1 may contact the second electrode 205 and the second lower wiring layer 113. The first contact plug CP1 may be electrically connected to the second electrode 205 and the second lower wiring layer 113. As shown in fig. 3A, the upper surface S1 of the second electrode 205 may have a stepped profile. For example, as shown in fig. 3A, the portion S1a of the upper surface S1 of the second electrode 205 covered by the first contact plug CP1 may be a portion recessed from the portion S1b of the upper surface S1 of the second electrode 205 covered by the second dielectric layer 207 (e.g., overlapped in a vertical direction perpendicular to the upper surface 100U of the substrate 100). The first contact plug CP1 may contact a portion S1a of the upper surface S1 of the second electrode 205 and may cover a portion S1a of the upper surface S1 of the second electrode 205 as shown in fig. 3A. First contact plug CP1 may be physically spaced apart (e.g., out of direct contact) from both first electrode 201 and third electrode 209 and electrically insulated from both first electrode 201 and third electrode 209.
The first contact plug CP1 may include a first portion P1 and a second portion P2. The first portion P1 may be at least partially disposed on the portion S1a of the upper surface S1 of the second electrode 205 (e.g., at least partially away from the upper surface 100U of the substrate 100 relative to the upper surface S1). The second portion P2 may be disposed at least partially under a lower surface L1 of the second electrode 205 that is in contact with the uppermost surface of the first dielectric layer 203 (e.g., at least partially between the lower surface L1 and the upper surface 100U of the substrate 100). The second portion P2 may be disposed at least partially below the upper surface S1 of the second electrode 205 (e.g., at least partially between the upper surface S1 and the upper surface 100U of the substrate 100). The first portion P1 may extend through the third hole H3 of the third electrode 209, and the second portion P2 may extend through the first hole H1 of the first electrode 201. The width Wa1 of the first portion P1 extending through the third hole H3 may be less than the width W1 of the third hole H3. The first portion P1 may be spaced apart from a sidewall of the third hole H3. The width Wa2 of the second portion P2 extending through the first hole H1 may be less than the width W2 of the first hole H1. The second portion P2 may be spaced apart from the sidewalls of the first hole H1. For example, a portion of the first dielectric layer 203 may be interposed between the second portion P2 and the sidewall of the first hole H1.
The first contact plug CP1 may have a sidewall SW 1. As shown in fig. 3A, sidewall SW1 of first contact plug CP1 may be physically spaced apart (e.g., out of direct contact) from both first electrode 201 and third electrode 209 and electrically insulated from both first electrode 201 and third electrode 209, e.g., based at least in part on being directly covered by portions of first dielectric layer 203, second electrode 205, and second dielectric layer 207 and physically out of direct contact from sidewall H3S of third hole H3. The side wall SW1 of the first contact plug CP1 may have a step portion SP. As shown in fig. 3A, the stepped portion SP of the sidewall SW1 of the first contact plug CP1 may be positioned adjacent to the upper surface S1 of the second electrode 205 (e.g., between the portion S1b of the upper surface S1 of the second electrode 205 covered by the second dielectric layer 207 and the lower surface L1 of the second electrode 205). The portion S1a of the upper surface S1 and the inner sidewall 205IS of the second electrode 205 may contact (e.g., directly contact) the step portion SP of the sidewall SW1 of the first contact plug CP 1. As shown in fig. 3A, the side wall SW1 of the first portion P1 of the first contact plug CP1 may be offset to the side wall SW1 of the second portion P2 of the first contact plug CP1 such that there is a step change (e.g., a discontinuous change in width) in the side wall SW1 between the first portion P1 and the second portion P2 (e.g., at the step portion SP). The width Wa1 of the first portion P1 of the first contact plug CP1 may be greater than the width Wa2 of the second portion P2 of the first contact plug CP 1. The width Wa1 of the first portion P1 of the first contact plug CP1 may be gradually (e.g., continuously) decreased in proportion to getting closer to the second portion P2 and/or in proportion to getting closer to the second electrode 205. The width of the second portion P2 of the first contact plug CP1 may be gradually (e.g., continuously) decreased in proportion to getting closer to the upper surface 100U of the substrate 100. The first contact plug CP1 may have a T shape. The first contact plug CP1 may include, for example, copper, aluminum, or tungsten.
Referring to fig. 2 and 3B, the second contact plug CP2 may extend through (e.g., penetrate) the second hole H2 of the second electrode 205. The second contact plug CP2 may extend through (e.g., penetrate) the fifth interlayer insulating layer 211, the third electrode 209, the second dielectric layer 207, the first dielectric layer 203, the first electrode 201, and the fourth interlayer insulating layer 123, and the third buffer insulating layer 121. The second contact plug CP2 may physically and electrically contact (e.g., directly contact) the third electrode 209, the first electrode 201, and the third lower wiring layer 115. Second contact plug CP2 may be physically spaced apart (e.g., out of direct contact) from second electrode 205 and electrically insulated from second electrode 205. The upper surface S2 of the first electrode 201 may have a stepped shape. For example, the portion S2a of the upper surface S2 of the first electrode 201 covered by the second contact plug CP2 may be a portion recessed from the portion S2b of the upper surface S2 of the first electrode 201 covered by the first dielectric layer 203. The upper surface S3 of the third electrode 209 may have a stepped profile. For example, the portion S3a of the upper surface S3 of the third electrode 209 covered by the second contact plug CP2 may be a portion recessed from the portion S3b of the upper surface S3 of the third electrode 209 covered by the fifth interlayer insulating layer 211.
The second contact plug CP2 may contact the portion S2a of the upper surface S2 of the first electrode 201 and the portion S3a of the upper surface S3 of the third electrode 209. The second contact plug CP2 may be spaced apart from the sidewall H2S of the second hole H2. For example, a portion of the second dielectric layer 207 may be interposed between the sidewall H2S of the second hole H2 and the second contact plug CP 2. A portion of the third electrode 209 filling a portion of the second hole H2 may be interposed between the second contact plug CP2 and a portion of the second dielectric layer 207 in the second hole H2.
The second contact plug CP2 may include a first portion P1a, a second portion P2a, and a third portion P3 a. As shown in fig. 3B, third portion P3a may be between first portion P1a and second portion P2 a. As shown in fig. 3B, the first portion P1a may be disposed at least partially below the lower surface L2 of the first electrode 201 (e.g., at least partially between the lower surface L2 and the upper surface 100U of the substrate 100). As shown in fig. 3B, the first portion P1a may be disposed below the upper surface S2 of the first electrode 201 (e.g., between the upper surface S2 and the upper surface 100U of the substrate 100). As shown in fig. 3B, the second portion P2a may be at least partially disposed on the recessed portion S3a of the upper surface S3 of the third electrode 209 (e.g., at least partially away from the upper surface 100U of the substrate 100 relative to the upper surface S3 of the third electrode 209). The third portion P3a may be at least partially disposed between the lower surface L3 of the third electrode 209 and the recessed portion S2a of the upper surface S2 of the first electrode 201. The third portion P3a may extend through the second hole H2 and may penetrate (e.g., extend through) both the first dielectric layer 203 and the second dielectric layer 207. As shown in fig. 3B, for example, the third portion P3a may extend through the portion of the second dielectric layer 207 that fills a portion of the second hole H2 and the portion of the third electrode 209 that fills the remaining portion of the second hole H2 that is not filled by the second dielectric layer 207. As shown in fig. 3B, a portion of the third electrode 209 may be between the second dielectric layer 207 and the second contact plug CP2 and may also be at least partially within the second hole H2 such that the portion of the third electrode 209 at least partially fills the second hole H2. The width Wa3 of the third portion P3a extending through the second hole H2 may be less than the width W3 of the second hole H2. As shown in fig. 3B, the width Wa2 of the second portion P2a may be greater than the width Wa1 of the first portion P1a and the width Wa3 of the third portion P3 a. The width Wa3 of the third portion P3a may be greater than the width Wa1 of the first portion P1 a. That is, the width Wa1 of the first portion P1a may be smaller than the width Wa2 of the second portion P2a and the width Wa3 of the third portion P3 a. The width Waa2 of the second portion P2a may gradually (e.g., continuously) decrease in proportion to approaching the third portion P3 a. The width Waa1 of the first portion P1a may gradually (e.g., continuously) decrease in proportion to approaching the upper surface 100U of the substrate 100.
The second contact plug CP2 may have a sidewall SW 2. The side wall SW2 of the second contact plug CP2 may have a plurality of step portions (e.g., SP1 and SP 2). The first step portion SP1 may be positioned adjacent to the upper surface S2 of the first electrode 201. The portion S2a of the upper surface S2 of the first electrode 201 and the inner sidewall 201IS of the first electrode 201 may contact the first step portion SP1 of the sidewall SW2 of the second contact plug CP2, and thus the third portion P3a may cover the portion S2a of the upper surface S2 of the first electrode 201. The first step portion SP1 may be located between the lower surface L2 of the first electrode 201 and the upper surface S2 of the first electrode 201. Specifically, the first step portion SP1 may be located between the lower surface L2 of the first electrode 201 and a portion (e.g., the portion S2b of the upper surface S2) of the upper surface S2 of the first electrode 201 that is covered by the first dielectric layer 203 (e.g., overlapped in the vertical direction perpendicular to the upper surface 100U of the substrate 100). The second step portion SP2 can be positioned adjacent to the upper surface S3 of the third electrode 209. The portion S3a of the upper surface S3 and the inner sidewall 209IS of the third electrode 209 may contact the second step portion SP2 of the sidewall SW2 of the second contact plug CP2, and thus the second portion P2a may cover the portion S3a of the upper surface S3 of the third electrode 209. The second step portion SP2 may be located between the lower surface L3 of the third electrode 209 and the upper surface S3 of the third electrode 209. Specifically, the second step portion SP2 may be located between the lower surface L3 of the third electrode 209 and a portion (e.g., the portion S3b of the upper surface S3) of the upper surface S3 of the third electrode 209 that is covered by the fifth interlayer insulating layer 211 (e.g., overlapped in the vertical direction perpendicular to the upper surface 100U of the substrate 100). As shown in fig. 3B, the side wall SW2 of the first portion P1a of the second contact plug CP2 may be offset to the side wall SW2 of the third portion P3a of the second contact plug CP2 such that there is a step change (e.g., a discontinuous change in width) in the side wall SW2 between the first portion P1a and the third portion P3a (e.g., at the first step portion SP 1). As shown in fig. 3B, the side wall SW2 of the third portion P3a of the second contact plug CP2 may be offset to the side wall SW2 of the second portion P2a of the second contact plug CP2 such that there is a step change (e.g., a discontinuous change in width) in the side wall SW2 between the second portion P2a and the third portion P3a (e.g., at the second step portion SP 2). The second contact plug CP2 may include a metal, such as copper, aluminum, or tungsten.
According to some example embodiments of the inventive concepts, the first contact plug CP1 may cover the portion S1a of the upper surface S1 of the second electrode 205 and may contact the second electrode 205. The second contact plug CP2 may cover a portion S2a of the upper surface S2 of the first electrode 201 and a portion S3a of the upper surface S3 of the third electrode 209, and may contact the first electrode 201 and the third electrode 209. Accordingly, the second contact plug CP2 may cover at least one of a portion (e.g., the portion S2a) of the upper surface S2 of the first electrode 201 and a portion (e.g., the portion S3a) of the upper surface S3 of the third electrode 209. A contact area between the first contact plug CP1 and the second electrode 205 may increase, and a contact area between each of the first electrode 201 and the third electrode 209 and the second contact plug CP2 may increase. Accordingly, the resistance of each of the first and second contact plugs CP1 and CP2 may be reduced.
Referring again to fig. 2, the third contact plug CP3 may contact the fourth lower wiring layer 117. The third contact plugs CP3 may extend through the third buffer insulating layer 121, the fourth interlayer insulating layer 123, the first and second dielectric layers 203 and 207, and the fifth interlayer insulating layer 211, and may contact the upper surface of the fourth lower wiring layer 117 to be electrically connected to the fourth lower wiring layer 117. The third contact plug CP3 may include a metal, such as copper, aluminum, or tungsten.
The first upper wiring layer 221, the second upper wiring layer 223, and the third upper wiring layer 225 may be disposed on the fifth interlayer insulating layer 211. The first upper wiring layer 221 may be disposed on an upper surface of the first contact plug CP1 and may be electrically connected to the first contact plug CP 1. The second upper wiring layer 223 may be disposed on an upper surface of the second contact plug CP2 and may be electrically connected to the second contact plug CP 2. The third upper wiring layer 225 may be disposed on an upper surface of the third contact plug CP3 and may be electrically connected to the third contact plug CP 3.
Fig. 4 is a cross-sectional view taken along line I-I' of fig. 1, illustrating a semiconductor device according to some example embodiments of the inventive concepts.
Referring to fig. 4, the third portion P3a of the second contact plug CP2 extending through the second hole H2 of the second electrode 205 may contact a portion of the second dielectric layer 207 covering sidewalls of the second hole H2. For example, the third electrode 209 may not be disposed between the third portion P3a of the second contact plug CP2 and the portion of the second dielectric layer 207 covering the sidewalls of the second hole H2. That is, unlike that shown in fig. 2, the third electrode 209 may not fill the second hole H2.
Fig. 5is a cross-sectional view taken along line I-I' of fig. 1, illustrating a semiconductor device according to some example embodiments of the inventive concepts.
Referring to fig. 5, the first contact plug CP1 may include a first portion P1 on the upper surface S1 of the second electrode 205 and a second portion P2 under the upper surface S1 of the second electrode 205. The first contact plug CP1 may extend through the second electrode 205 and contact the second electrode 205, but may not cover the upper surface S1 of the second electrode 205. For example, the sidewall SW1 of the first contact plug CP1 may be flat. That is, the sidewall SW1 of the first portion P1 of the first contact plug CP1 may be aligned with the sidewall SW1 of the second portion P2 of the first contact plug CP 1. As shown in fig. 5, the side wall SW1 of the first portion P1 and the side wall SW1 of the second portion P2 may be inclined with respect to the upper surface 100U of the substrate 100. The side wall SW1 of the first portion P1 and the side wall SW1 of the second portion P2 may be obliquely aligned with each other. In some embodiments, the sidewall SW1 of the first portion P1 and the sidewall SW1 of the second portion P2 may be perpendicular to the upper surface 100U of the substrate 100. That is, the side wall SW1 of the first portion P1 and the side wall SW1 of the second portion P2 may be vertically aligned with each other (e.g., aligned in a vertical direction perpendicular to the upper surface 100U of the substrate 100). The first contact plug CP1 may have a tapered cross-section or a rectangular cross-section.
Fig. 6 is a cross-sectional view taken along line I-I' of fig. 1, illustrating a semiconductor device according to some example embodiments of the inventive concepts.
Referring to fig. 6, the second contact plug CP2 may include a first portion P1a, a second portion P2a, and a third portion P3 a. The first portion P1a may be disposed under the upper surface S2 of the first electrode 201. The second portion P2a may be disposed on the upper surface S3 of the third electrode 209. The third portion P3a may be disposed between the first portion P1a and the second portion P2 a. The second contact plug CP2 may extend through the first and third electrodes 201 and 209 and may contact the first and third electrodes 201 and 209, but may not cover the upper surface S2 of the first electrode 201 and the upper surface S3 of the third electrode 209. For example, the sidewall SW2 of the second contact plug CP2 may be flat. That is, in the second contact plug CP2, the sidewall SW2 of the first portion P1a, the sidewall SW2 of the second portion P2a, and the sidewall SW2 of the third portion P3a may be aligned with each other, for example, as shown in fig. 6, such that the sidewall SW2 of the first portion P1a, the sidewall SW2 of the second portion P2a, and the sidewall SW2 of the third portion P3a define respective portions of a single continuous three-dimensional geometric-shaped surface (e.g., respective portions of a single tapered shape or a conical surface, as shown in fig. 6).
As shown in fig. 6, in the second contact plug CP2, the side wall SW2 of the first portion P1a, the side wall SW2 of the second portion P2a, and the side wall SW2 of the third portion P3a may be inclined with respect to the upper surface 100U of the substrate 100 and may be obliquely aligned with each other. In some embodiments, in the second contact plug CP2, the sidewall SW2 of the first portion P1a, the sidewall SW2 of the second portion P2a, and the sidewall SW2 of the third portion P3a may be perpendicular to the upper surface 100U of the substrate 100 and may be vertically aligned with each other (e.g., aligned in a vertical direction perpendicular to the upper surface 100U of the substrate 100). The second contact plug CP2 may have a tapered cross-section or a rectangular cross-section.
Fig. 7A, 7B, 7C, 7D, 7E, 7F, and 7G illustrate methods of manufacturing a semiconductor device according to some example embodiments of the inventive concepts, and are sectional views taken along line I-I' of fig. 1.
Referring to fig. 7A, a first interlayer insulating layer 101 may be formed on a substrate 100. The first lower wiring layer 103 may be formed in the first interlayer insulating layer 101. The upper surface of the first lower wiring layer 103 may be coplanar with the upper surface of the first interlayer insulating layer 101. The first buffer insulating layer 105 may be formed on an upper surface of the first interlayer insulating layer 101. The first buffer insulating layer 105 may cover a portion of the upper surface of the first lower wiring layer 103. The second interlayer insulating layer 107 may be formed to cover the upper surface of the first buffer insulating layer 105. The conductive through via 119 may be formed to extend through the first buffer insulating layer 105 and the second interlayer insulating layer 107. The conductive through via 119 may contact an upper surface of the first lower wiring layer 103. The second buffer insulating layer 109 and the third interlayer insulating layer 111 may be sequentially formed on the upper surface of the second interlayer insulating layer 107. The second lower wiring layer 113, the third lower wiring layer 115, and the fourth lower wiring layer 117 may be disposed in the second buffer insulating layer 109 and the third interlayer insulating layer 111. The third lower wiring layer 115 may contact the upper surface of the conductive through via 119. The upper surfaces of the second to fourth lower wiring layers 113, 115, and 117 may be coplanar with the upper surface of the third interlayer insulating layer 111.
The third buffer insulating layer 121 may be formed on an upper surface of the third interlayer insulating layer 111. The third buffer insulating layer 121 may cover an upper surface of the third interlayer insulating layer 111 and upper surfaces of the second to fourth lower wiring layers 113, 115, and 117. The fourth interlayer insulating layer 123 may be formed to cover an upper surface of the third buffer insulating layer 121. The first electrode layer EL1 may be formed on the upper surface of the fourth interlayer insulating layer 123. The first electrode layer EL1 may include, for example, TaN, Ta, Al, Ti, TiN, TaSiN, WN, and/or WSiN.
Referring to fig. 7B, a first mask pattern MP1 may be formed on the first electrode layer EL 1. The first electrode layer EL1 may be patterned using the first mask pattern MP1 as an etch mask to form the first electrode 201. The first mask pattern MP1 may be, for example, a photoresist pattern. A portion of the upper surface of the fourth interlayer insulating layer 123 may be exposed by the patterning process of the first electrode layer EL 1. The first electrode 201 may include a first hole H1 and a fifth hole H5. The first holes H1 may be formed to vertically overlap with the second lower wiring layer 113 (e.g., overlap in a vertical direction perpendicular to the upper surface 100U of the substrate 100). The fifth holes H5 may be formed to vertically overlap the third lower wiring layer 115. The patterning process of the first electrode layer EL1 may be performed, for example, by a dry etching process. After the patterning process of the first electrode layer EL 1is performed, the first mask pattern MP1 may be removed by, for example, an ashing process or a stripping process.
Referring to fig. 7C, a first dielectric layer 203 may be formed on the first electrode 201 and the fourth interlayer insulating layer 123. The first dielectric layer 203 may conformally cover the upper surface and sidewalls of the first electrode 201 and the upper surface of the fourth interlayer insulating layer 123. The first dielectric layer 203 may be formed to cover bottom surfaces and sidewalls of the first hole H1 and bottom surfaces and sidewalls of the third hole H5. For example, the first dielectric layer 203 may conformally cover sidewalls of the first hole H1 and a portion of the upper surface of the fourth interlayer insulating layer 123 exposed by the first hole H1. For example, the first dielectric layer 203 may conformally cover sidewalls of the fifth hole H5 and a portion of the upper surface of the fourth interlayer insulating layer 123 exposed by the fifth hole H5. The first dielectric layer 203 may comprise, for example, Si3N4、Ta2O5、Al2O3And/or ZrO2。
The second electrode layer EL2 may be formed on the first dielectric layer 203. The second electrode layer EL2 may cover the upper surface of the first dielectric layer 203. The second electrode layer EL2 may fill the first hole H1 in which the first dielectric layer 203 is formed and the fifth hole H5 in which the first dielectric layer 203 is formed. The second electrode layer EL2 may include, for example, TaN, Ta, Al, Ti, TiN, TaSiN, WN, and/or WSiN.
Referring to fig. 7D, a second mask pattern MP2 may be formed on the second electrode layer EL 2. The second electrode layer EL2 may be patterned using the second mask pattern MP2 as an etch mask to form the second electrode 205. The second mask pattern MP2 may be, for example, a photoresist pattern. The second electrode 205 may expose a portion of the upper surface of the first dielectric layer 203. The second electrode 205 may include a second hole H2 and a sixth hole H6. The second hole H2 may be formed to vertically overlap the fifth hole H5 of the first electrode 201. The sixth hole H6 may be formed to vertically overlap the first hole H1 of the first electrode 201. As an example, the width of the second hole H2 of the second electrode 205 may be greater than the width of the fifth hole H5 of the first electrode 201, and the width of the sixth hole H6 of the second electrode 205 may be less than the width of the first hole H1 of the first electrode 201.
A portion of the second electrode layer EL2 filling the fifth hole H5 of the first electrode 201 may be removed by a patterning process. Accordingly, a portion of the first dielectric layer 203 may be exposed by the second hole H2. The portion of the second electrode layer EL2 filling the first hole H1 may be partially removed by a patterning process. A portion of the upper surface of the first dielectric layer 203 may be exposed by the sixth hole H6 of the second electrode 205. After the patterning process of the second electrode layer EL2 is performed, a portion of the second electrode 205 may remain on a portion of the first dielectric layer 203 covering sidewalls of the first hole H1. The patterning process of the second electrode layer EL2 may be performed, for example, by a dry etching process. After the patterning process of the second electrode layer EL2 is performed, the second mask pattern MP2 may be removed. The second mask pattern MP2 may be removed by, for example, an ashing process or a stripping process.
Referring to FIG. 7E, secondA dielectric layer 207 may be formed on the second electrode 205. The second dielectric layer 207 may conformally cover the upper surface and sidewalls of the second electrode 205, the portion of the upper surface of the first dielectric layer 203 exposed by the second electrode 205, and the inner surface of the second hole H2 of the second electrode 205. The second dielectric layer 207 may fill the sixth hole H6 of the second electrode 205. The second dielectric layer 207 may comprise, for example, Si3N4、Ta2O5、Al2O3And/or ZrO2. The third electrode layer EL3 may be formed on the second dielectric layer 207. The third electrode layer EL3 may conformally cover the upper surface of the second dielectric layer 207 and may fill the second hole H2 in which the second dielectric layer 207 is formed. The third electrode layer EL3 may include, for example, TaN, Ta, Al, Ti, TiN, TaSiN, WN, and/or WSiN.
Referring to fig. 7F, a third mask pattern MP3 may be formed on the third electrode layer EL 3. The third electrode layer EL3 may be patterned using the third mask pattern MP3 as an etch mask to form the third electrode 209. The third mask pattern MP3 may be, for example, a photoresist pattern. The third electrode 209 may expose a portion of the upper surface of the second dielectric layer 207. The third electrode 209 may include a third hole H3 and a seventh hole H7. The third hole H3 may be formed to vertically overlap the sixth hole H6 of the second electrode 205 and the first hole H1 of the first electrode 201. The seventh hole H7 may be formed to vertically overlap the second hole H2 of the second electrode 205 and the fifth hole H5 of the first electrode 201. As an example, the width of the third hole H3 of the third electrode 209 may be greater than the width of the sixth hole H6 of the second electrode 205, and the width of the seventh hole H7 of the third electrode 209 may be less than the width of the second hole H2 of the second electrode 205.
The portion of the third electrode layer EL3 filling the second hole H2 of the second electrode 205 may be partially removed by a patterning process. Accordingly, a portion of the upper surface of the second dielectric layer 207 may be exposed by the seventh hole H7 of the third electrode 209. After the patterning process of the third electrode layer EL3 is performed, a portion of the third electrode 209 may remain on a portion of the second dielectric layer 207 covering sidewalls of the second hole H2. A portion of the upper surface of the second dielectric layer 207 may be exposed by the third hole H3 of the third electrode 209. The patterning process of the third electrode layer EL3 may be performed, for example, by a dry etching process. After the patterning process of the third electrode layer EL3 is performed, the third mask pattern MP3 may be removed. The third mask pattern MP3 may be removed by, for example, an ashing process or a stripping process.
Referring to fig. 7G, a fifth interlayer insulating layer 211 may be formed on the third electrode 209 and the second dielectric layer 207. The fifth interlayer insulating layer 211 may be formed to fill the third hole H3 and the seventh hole H7 of the third electrode 209. The fifth interlayer insulating layer 211 may cover the upper surface and sidewalls of the third electrode 209 and the upper surface of the second dielectric layer 207.
The first through hole TH1, the second through hole TH2, and the third through hole TH3 may be formed. The first through hole TH1 may be formed through the fifth interlayer insulating layer 211, the second electrode 205, the second dielectric layer 207, the first dielectric layer 203, the fourth interlayer insulating layer 123, and the third buffer insulating layer 121. The first through holes TH1 may be formed in the first hole H1 of the first electrode 201, the sixth hole H6 of the second electrode 205, and the third hole H3 of the third electrode 209. A portion of the upper surface and the inner sidewall of the second electrode 205 may be exposed by the first through hole TH 1. The width of the first through hole TH1 formed on the upper surface of the second electrode 205 may be less than the width of the third hole H3 of the third electrode 209 and may be greater than the width of the sixth hole H6 of the second electrode 205. The width of the first through hole TH1 formed under the upper surface of the second electrode 205 may be less than the width of the first hole H1 of the first electrode 201. The first through holes TH1 may not expose the first and third electrodes 201 and 209. The first through holes TH1 may expose a portion of the upper surface of the second lower wiring layer 113.
The second through hole TH2 may be formed through the fifth interlayer insulating layer 211, the third electrode 209, the second dielectric layer 207, the first dielectric layer 203, the first electrode 201, the fourth interlayer insulating layer 123, and the third buffer insulating layer 121. The second through holes TH2 may be formed in the fifth hole H5 of the first electrode 201, the second hole H2 of the second electrode 205, and the seventh hole H7 of the third electrode 209. The second through hole TH2 may expose a portion of the upper surface and an inner sidewall of the third electrode 209 and a portion of the upper surface and an inner sidewall of the first electrode 201. The width of the second through holes TH2 formed on the upper surface of the third electrode 209 may be greater than the width of the seventh hole H7 of the third electrode 209. The width of the second through holes TH2 formed on the upper surface of the first electrode 201 may be greater than the width of the fifth holes H5 of the first electrode 201. The second through holes TH2 may not expose the second electrode 205. The second through holes TH2 may expose a portion of the upper surface of the third lower wiring layer 115.
The third through hole TH3 may pass through the fifth interlayer insulating layer 211, the first and second dielectric layers 203 and 207, the fourth interlayer insulating layer 123, and the third buffer insulating layer 121. The third through holes TH3 may expose a portion of the upper surface of the fourth lower wiring layer 117. The first, second, and third through holes TH1, TH2, and TH3 may be formed through an etching process. The etching process may be performed using an etching recipe for etching the fifth interlayer insulating layer 211, the first and second dielectric layers 203 and 207, the fourth interlayer insulating layer 123, and the third buffer insulating layer 121. The etching recipe may have an etching selectivity with respect to the first to third electrodes 201, 205, and 209 and the second to fourth lower wiring layers 113, 115, and 117. The etching process may be performed by, for example, a dry etching process.
Referring again to fig. 2, a first contact plug CP1, a second contact plug CP2, and a third contact plug CP3 may be formed. The first contact plug CP1 may be formed in the first through hole TH 1. The second contact plug CP2 may be formed in the second through hole TH 2. The third contact plug CP3 may be formed in the third through hole TH 3. The first contact plug CP1 may be formed to cover the portion of the upper surface of the second electrode 205 exposed by the first through hole TH1 and the inner sidewall. The second contact plug CP2 may be formed to cover the portion and the inner sidewall of the upper surface of the third electrode 209 exposed by the second through hole TH2 and the portion and the inner sidewall of the upper surface of the first electrode 201 exposed by the second through hole TH 2. The first to third upper wiring layers 221, 223 and 225 may be formed on the first to third contact plugs CP1, CP2 and CP3, respectively. For example, the first upper wiring layer 221 may be formed on the upper surface of the first contact plug CP 1. The second upper wiring layer 223 may be formed on the upper surface of the second contact plug CP 2. The third upper wiring layer 225 may be formed on the upper surface of the third contact plug CP 3.
While the inventive concept has been shown and described with reference to certain 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 therein without departing from the spirit and scope of the inventive concept as set forth in the following claims.
This application claims priority from korean patent application No. 10-2019-0052419 filed by the korean intellectual property office on 3/5/2019, the disclosure of which is incorporated herein by reference in its entirety.
