阅读说明：本技术 包括接触件和与接触件侧壁交界的导电线的半导体装置 (Semiconductor device including contact and conductive line interfacing with contact sidewall ) 是由 梁起豪 于 2019-08-27 设计创作，主要内容包括：公开了一种半导体装置,包括：衬底；顺序地堆叠在衬底上的第一介电层和第二介电层；接触件,其穿透第一介电层并朝向衬底延伸；以及导电线,其设置在第二介电层中并电连接到接触件。导电线在第一方向上延伸。接触件包括位于第一介电层中的下段和位于第二介电层中的上段。导电线在第二方向上的宽度随着距衬底的距离减小而减小。第二方向与第一方向相交。接触件的上段的侧壁与导电线接触。(Disclosed is a semiconductor device including: a substrate; a first dielectric layer and a second dielectric layer sequentially stacked on the substrate; a contact penetrating the first dielectric layer and extending toward the substrate; and a conductive line disposed in the second dielectric layer and electrically connected to the contact. The conductive lines extend in a first direction. The contact includes a lower section in the first dielectric layer and an upper section in the second dielectric layer. The width of the conductive line in the second direction decreases with decreasing distance from the substrate. The second direction intersects the first direction. The side wall of the upper section of the contact is in contact with the conductive line.)

1. A semiconductor device, comprising:

a substrate;

a first dielectric layer and a second dielectric layer sequentially stacked on the substrate;

a contact penetrating the first dielectric layer and extending toward the substrate, the contact comprising a lower section in the first dielectric layer and an upper section in the second dielectric layer; and

a conductive line extending in a first direction in the second dielectric layer and electrically connected to the contact,

wherein a sidewall of the upper section of the contact is in contact with the conductive line.

2. The semiconductor device of claim 1, wherein the sidewalls of the upper section of the contact comprise a first portion in contact with the conductive line and a second portion in contact with the second dielectric layer.

3. The semiconductor device of claim 1, wherein the conductive line completely covers a sidewall of the upper segment of the contact.

4. The semiconductor device according to claim 1, wherein a width of the upper section of the contact in the second direction increases with decreasing distance from the substrate.

5. The semiconductor device according to claim 1, wherein a top surface of the upper section of the contact is surrounded by a side wall of the upper section of the contact when viewed from a plane.

6. The semiconductor device according to claim 1, wherein a width of the lower section of the contact in the second direction decreases as a distance from the substrate decreases.

7. The semiconductor device of claim 1, further comprising a barrier layer between the first dielectric layer and a lower section of the contact.

8. A semiconductor device, comprising:

a substrate;

a first dielectric layer and a second dielectric layer sequentially stacked on the substrate;

a contact penetrating the first dielectric layer and extending toward the substrate; and

a conductive line disposed in the second dielectric layer and electrically connected to the contact, the conductive line extending in a first direction,

wherein the contact comprises a lower section in the first dielectric layer and an upper section in the second dielectric layer,

wherein a width of an upper section of the contact in a second direction that intersects the first direction increases with decreasing distance from the substrate, and

wherein a width of the conductive line in the second direction decreases with decreasing distance from the substrate.

9. The semiconductor device of claim 8, wherein a sidewall of an upper segment of the contact is in contact with the conductive line.

10. The semiconductor device of claim 9, wherein the sidewalls of the upper section of the contact comprise a first portion in contact with the conductive line and a second portion in contact with the second dielectric layer.

11. The semiconductor device according to claim 8, wherein a maximum width of the conductive line in the second direction is larger than a minimum width of an upper section of the contact in the second direction.

12. The semiconductor device according to claim 11, wherein a minimum width of the conductive line in the second direction is smaller than a maximum width of an upper section of the contact in the second direction.

13. The semiconductor device according to claim 12, wherein a maximum width of the conductive line in the second direction is larger than a maximum width of an upper section of the contact in the second direction.

14. The semiconductor device according to claim 9, wherein a top surface of the upper section of the contact is surrounded by a side wall of the upper section of the contact when viewed from a plane.

15. A semiconductor device, comprising:

a substrate;

a first dielectric layer and a second dielectric layer sequentially stacked on the substrate;

a contact penetrating the first dielectric layer and extending toward the substrate; and

a conductive line in the second dielectric layer and electrically connected to the contact, the conductive line extending in the first direction,

wherein the contact comprises a lower section in the first dielectric layer and an upper section in the second dielectric layer,

wherein the conductive line includes a recess portion that is located in a lowermost surface of the conductive line and is recessed in a direction away from the substrate, and

wherein the upper section of the contact is in contact with the recess.

16. The semiconductor device of claim 15, wherein the conductive line completely covers a sidewall of the upper segment of the contact.

17. The semiconductor device of claim 16, wherein a width of the conductive line in a second direction decreases with decreasing distance from the substrate, the second direction intersecting the first direction.

18. The semiconductor device according to claim 17, wherein a width of an upper section of the contact in the second direction increases as a distance from a substrate decreases.

19. The semiconductor device of claim 18, wherein a maximum width of an upper segment of the contact in the second direction is substantially equal to a minimum width of the conductive line in the second direction.

20. The semiconductor device of claim 15, wherein opposing sidewalls of the upper segment of the contact are inwardly sloped toward each other relative to the substrate and opposing sidewalls of the conductive line are outwardly sloped away from each other relative to the substrate to define an hourglass-shaped cross-section at boundaries where the opposing sidewalls of the upper segment of the contact meet the opposing sidewalls of the conductive line.

Technical Field

The inventive concept relates to interconnect structures in semiconductor devices.

Background

Semiconductor devices are widely used in the electronics industry because of their small size, versatility, and/or low manufacturing cost. The semiconductor device may include a memory device for storing data, a logic device for processing data, and a hybrid device for simultaneously operating various functions.

With the advanced development of the electronics industry, semiconductor devices have been increasingly used for high integration. Since there is a problem in that a process margin is reduced in an exposure process for defining a fine pattern, it is increasingly difficult to manufacture a semiconductor device. With the advanced development of the electronics industry, semiconductor devices have also been increasingly used at high speeds. Various studies have been made to meet the demand for high integration and/or high speed in semiconductor devices.

Disclosure of Invention

Embodiments according to the inventive concept may provide a semiconductor device including a contact and a conductive line interfacing with a sidewall of the contact. According to the embodiments, a semiconductor device may include a substrate and a first dielectric layer and a second dielectric layer sequentially stacked on the substrate. A contact may penetrate the first dielectric layer and extend toward the substrate, and the contact may include a lower section in the first dielectric layer and an upper section in the second dielectric layer. The conductive line may extend in the second dielectric layer in the first direction and be electrically connected to the contact. The side wall of the upper section of the contact is in contact with the conductive line.

According to some example embodiments of the inventive concepts, a semiconductor device may include a substrate and first and second dielectric layers sequentially stacked on the substrate. The contact may penetrate the first dielectric layer and extend toward the substrate. A conductive line may be disposed in the second dielectric layer and electrically connected to the contact, wherein the conductive line extends in a first direction, wherein the contact may include a lower section in the first dielectric layer and an upper section in the second dielectric layer, wherein a width of the upper section of the contact in a second direction increases with decreasing distance from the substrate, the second direction intersecting the first direction, wherein the width of the conductive line in the second direction decreases with decreasing distance from the substrate.

According to some example embodiments of the inventive concepts, a semiconductor device may include first and second dielectric layers sequentially stacked on a substrate and a contact passing through the first dielectric layer and extending toward the substrate. A conductive line may be located in the second dielectric layer and electrically connected to the contact, wherein the conductive line extends in the first direction, wherein the contact includes a lower segment located in the first dielectric layer and an upper segment located in the second dielectric layer. The conductive line may include a recess portion located in a lowermost surface of the conductive line and recessed in a direction away from the substrate, the upper section of the contact being in contact with the recess portion.

Drawings

Fig. 1A illustrates a plan view showing a semiconductor apparatus according to some example embodiments of the inventive concepts.

FIG. 1B shows a cross-sectional view taken along line A-A' of FIG. 1A.

FIG. 1C shows a cross-sectional view taken along line B-B' of FIG. 1A.

FIG. 1D shows a cross-sectional view taken along line C-C' of FIG. 1A.

Fig. 2A, 3A and 4A illustrate plan views showing methods for manufacturing a semiconductor device according to some example embodiments of the inventive concept.

Fig. 2B, 3B and 4B show cross-sectional views taken along line a-a' of fig. 2A, 3A and 4A, respectively.

Fig. 4C shows a cross-sectional view taken along line B-B' of fig. 4A.

Fig. 4D shows a cross-sectional view taken along line C-C' of fig. 4A.

Fig. 5A illustrates a plan view showing a semiconductor apparatus according to some example embodiments of the inventive concepts.

Fig. 5B shows a cross-sectional view taken along line a-a' of fig. 5A.

Fig. 6 illustrates a cross-sectional view showing a semiconductor apparatus according to some example embodiments of the inventive concepts.

Detailed Description

Fig. 1A illustrates a plan view showing a semiconductor apparatus according to some example embodiments of the inventive concepts. FIG. 1B shows a cross-sectional view taken along line A-A' of FIG. 1A. FIG. 1C shows a cross-sectional view taken along line B-B' of FIG. 1A. FIG. 1D shows a cross-sectional view taken along line C-C' of FIG. 1A.

Referring to fig. 1A, 1B, 1C, and 1D, a first dielectric layer 110 and a second dielectric layer 120 may be sequentially disposed on a substrate 100. The substrate 100 may be a semiconductor substrate. For example, the substrate 100 may be a silicon substrate, a germanium substrate, or a silicon germanium substrate. The substrate 100 may have transistors and/or memory cells disposed thereon. The first dielectric layer 110 may include a silicon oxide layer or a silicon oxynitride layer. The second dielectric layer 120 may include a material having an etch selectivity with respect to the first dielectric layer 110. For example, the second dielectric layer 120 may include tetraethyl orthosilicate (TEOS).

The conductive line ML may be disposed on the first dielectric layer 110. The conductive lines ML may be disposed in the second dielectric layer 120. Each of the conductive lines ML may have a bar shape or a line shape extending in the first direction D1. The first direction D1 may be parallel to the top surface of the substrate 100. The conductive lines ML may be spaced apart from each other in the second direction D2. For example, the conductive lines ML may be arranged in the second direction D2. The second direction D2 may be parallel to the top surface of the substrate 100 and may intersect the first direction D1. Conductive line ML may include copper or aluminum.

Each of the conductive lines ML may include a first sidewall MLs1 and a second sidewall MLs 2. The first sidewall MLS1 may stand opposite to the second sidewall MLS 2. The first and second sidewalls MLS1 and MLS2 may extend in the first direction D1. Each of the first and second sidewalls MLS1 and MLS2 may have a slope with respect to the top surface of the substrate 100. The conductive lines ML may have a width in the second direction D2, which may decrease as the distance from the substrate 100 decreases. Conductive line ML may have a minimum width or first width W1 in second direction D2. Conductive line ML may have a first width W1 at its bottom. Conductive line ML may have a maximum width or second width W2 in second direction D2. Conductive line ML may have a second width W2 at its top. The second width W2 may be greater than the first width W1. The conductive lines ML may include recesses RS recessed toward a direction away from the substrate 100. The recess RS may be disposed at a lower portion of the conductive line ML.

The substrate 100 may be provided with a contact CT that electrically connects the conductive line ML to the substrate 100. The conductive lines ML may be electrically connected to transistors and/or memory cells on the substrate 100 through contacts CT. The contact CT may penetrate the first dielectric layer 110 and extend in the third direction D3. The contact CT may extend toward the substrate 100. The third direction D3 may be perpendicular to the top surface of the substrate 100. The contact CT may include a conductive material. The contact CT may include a material identical to or different from that of the conductive line ML. For example, the contact CT may comprise metal or doped silicon.

Each of the contacts CT may include a lower section CTL disposed in the first dielectric layer 110 and an upper section CTU disposed on the lower section CTL. The upper segment CTU may be disposed in the second dielectric layer 120. The lower segment CTL may be surrounded by the first dielectric layer 110 when viewed from above the plane. The upper CTU may be surrounded by the second dielectric layer 120 when viewed from above the plane. The upper section CTU may be in contact with the conductive line ML. The upper section CTU may fill the recess RS of the conductive line ML. The upper segment CTU may have a width in the second direction D2, which may increase as the distance from the substrate 100 decreases. The lower segment CTL may have a width in the second direction D2, which may decrease as the distance from the substrate 100 decreases. The upper segment CTU may have a minimum width or a third width W3 in the second direction D2. Third width W3 may be less than first width W1 of conductive line ML. The upper segment CTU may have a maximum width or a fourth width W4 in the second direction D2. Fourth width W4 may be greater than first width W1 of conductive line ML. Fourth width W4 may be less than second width W2 of conductive line ML.

The upper section CTU of the contact CT may have a top surface CTUT and a third sidewall CTUs. The top surface CTUT may have a circular shape when viewed from a plane. The third sidewall CTUS may surround the top surface CTUT when viewed from above the plane. The third sidewall CTUS may be inclined to have a slope with respect to the top surface of the substrate 100. The inclination of the third sidewall CTUS may be opposite to the inclination of the first and second sidewalls MLS1 and MLS 2.

The top surface CTUT may be covered by the conductive lines ML. For example, the top surface CTUT may be in contact with the conductive line ML.

The third sidewall CTUS may comprise a first portion CTUS1 and a second portion CTUS 2. The first portion CTUS1 may be a portion connected to the top surface CTUT of the contact CT. The second portion CTUS2 may be part of the lower segment CTL connected to the contact CT. The first portion CTUS1 of the third sidewall CTUS may be covered by a conductive line ML. For example, the first portion CTUS1 of the third sidewall CTUS may be in contact with the conductive line ML. The second portion CTUS2 of the third sidewall CTUS may not be covered by the conductive lines ML. For example, the second portion CTUS2 of the third sidewall CTUS may not be in contact with the conductive line ML. The second portion CTUS2 of the third sidewall CTUS may be covered by the second dielectric layer 120. For example, the second portion of the third sidewall CTUS2 may be in contact with the second dielectric layer 120.

The third sidewall CTUs of the upper segment CTU of the contact CT may be in contact with the first and second sidewalls MLs1 and MLs2 of the conductive line ML. The first boundary BO1 may be defined as a boundary indicating that the third sidewall CTUS is in contact with the first sidewall MLS 1. The second boundary BO2 may be defined as a boundary indicating that the third sidewall CTUS is in contact with the second sidewall MLS 2. The first sidewall MLS1, the third sidewall CTUS, and the second dielectric layer 120 may contact each other at a first boundary BO 1. The second sidewall MLS2, the third sidewall CTUS, and the second dielectric layer 120 may contact each other at a second boundary BO 2. The first boundary BO1 and the second boundary BO2 may be curved when viewed in a plane (see fig. 1A). The first boundary BO1 and the second boundary BO2 may divide the third sidewall CTUS into a first portion CTUS1 and a second portion CTUS 2. Thus, the cross-section of the structure shown in fig. 1B may define an hourglass shape at the boundary of the conductive line ML and the contact CT.

The barrier layer BL may be disposed to conformally cover the sidewalls and bottom surface of the lower section CTL of the contact CT. Each of the barrier layers BL may be interposed between the contact CT and the first dielectric layer 110. The barrier layer BL may include titanium nitride.

According to some example embodiments of the inventive concept, since the conductive line ML and the contact CT contact each other at the third sidewall CTUs of the upper segment CTU, a relatively large contact area may be provided between the conductive line ML and the contact CT. As a result, it may be possible to improve the characteristics of the interface resistance between the conductive line ML and the contact CT.

Fig. 2A, 3A and 4A illustrate plan views showing methods of manufacturing a semiconductor device according to some example embodiments of the inventive concept. Fig. 2B, 3B and 4B show cross-sectional views taken along line a-a' of fig. 2A, 3A and 4A, respectively. Fig. 4C shows a cross-sectional view taken along line B-B' of fig. 4A. Fig. 4D shows a cross-sectional view taken along line C-C' of fig. 4A.

Referring to fig. 2A and 2B, a first dielectric layer 110 and a third dielectric layer 130 may be sequentially formed on a substrate 100. The first dielectric layer 110 may include a silicon oxide layer or a silicon oxynitride layer. The third dielectric layer 130 may include a material having an etch selectivity with respect to the first dielectric layer 110. For example, third dielectric layer 130 may include tetraethyl orthosilicate (TEOS).

The barrier layer BL and the contact CT may be formed in the first dielectric layer 110 and the third dielectric layer 130. The contact CT may extend in the third direction D3 and penetrate through the first dielectric layer 110 and the third dielectric layer 130. Each of the contacts CT may include a lower section CTL disposed in the first dielectric layer 110 and an upper section CTU disposed on the lower section CTL. The upper segment CTU may be disposed in the third dielectric layer 130. The barrier layer BL may conformally cover the bottom surface and the sidewalls of the contact CT.

The formation of the barrier layer BL and the contact CT may include: patterning the first dielectric layer 110 and the third dielectric layer 130; forming a barrier material layer conformally on the entire surface of the substrate 100; forming a contact material layer on the barrier material layer; and performing a planarization process to partially remove the barrier material layer and the contact material layer. The planarization process may be continued until the top surface of the third dielectric layer 130 is exposed. The planarization process may include a chemical mechanical polishing process. The barrier material layer may include titanium nitride. The contact material layer may include a conductive material. For example, the contact material layer may include a metal or doped silicon.

Referring to fig. 3A and 3B, a first etching process may be performed to remove the third dielectric layer 130. For example, the first etching process may simultaneously remove the third dielectric layer 130, the barrier layer BL located in the third dielectric layer 130, and a portion of the upper section CTU of the contact CT. For another example, a first etching process may be performed to remove the third dielectric layer 130, and then a second etching process may be performed to remove the exposed portion of the barrier layer BL and a portion of the exposed portion of the upper segment CTU of the contact CT. The partial removal of the upper section CTU of the contact CT may define a top surface CTUT and a third sidewall CTUs at the upper section CTU of the contact CT. The removal of the third dielectric layer 130 may expose the upper segment CTU of the contact CT.

Referring to fig. 4A, 4B, 4C, and 4D, a second dielectric layer 120 may be formed on the first dielectric layer 110. The second dielectric layer 120 may cover the upper section CTU of the contact CT. The second dielectric layer 120 may include a material having an etch selectivity with respect to the first dielectric layer 110. For example, the second dielectric layer 120 may include tetraethyl orthosilicate (TEOS).

The second dielectric layer 120 may be patterned to form trenches TR in the second dielectric layer 120. The trenches TR may extend in a first direction D1. The grooves TR may be spaced apart from each other in the second direction D2. For example, the trenches TR may be arranged in the second direction D2. The trench TR may have a width in the second direction D2, which may decrease as the distance from the substrate 100 decreases. The trench TR may have sidewalls each having a slope with respect to the top surface of the substrate 100.

The trench TR may expose a top surface CTUT of the upper section CTU of the contact CT. The third sidewall CTUs of the upper segment CTU of the contact CT may have a first portion CTUs1 exposed to the trench TR.

Referring back to fig. 1A, 1B, 1C, and 1D, the conductive line ML may be formed to fill the trench TR. The conductive lines ML may cover the top surfaces CTUT of the upper segments CTU of the contacts CT. The conductive line ML may cover a first portion CTUs1 of the third sidewall CTUs of the upper segment CTU of the contact CT.

The formation of the conductive line ML may include forming a conductive material layer on the entire surface of the substrate 100 and performing a planarization process to partially remove the conductive material layer. The planarization process may continue until the top surface of the second dielectric layer 120 is exposed. The planarization process may include a chemical mechanical polishing process. The layer of conductive material may comprise copper or aluminum.

Fig. 5A illustrates a plan view showing a semiconductor apparatus according to some example embodiments of the inventive concepts. Fig. 5B shows a cross-sectional view taken along line a-a' of fig. 5A. In the following embodiments, detailed descriptions of technical features overlapping with those discussed above with reference to fig. 1A, 1B, 1C, and 1D will be omitted, and differences thereof will be discussed in detail.

Referring to fig. 5A and 5B, the conductive line ML may completely cover the third sidewall CTUs of the upper segment CTU of the contact CT. For example, the third sidewall CTUS may not be in contact with the second dielectric layer 120. The conductive lines ML may separate the third sidewalls CTUS and the second dielectric layer 120 from each other.

Conductive line ML may have a minimum width or fifth width W5 in second direction D2. The upper segment CTU of the contact CT may have a maximum width or a sixth width W6 in the second direction D2. The fifth width W5 and the sixth width W6 may be substantially the same.

Fig. 6 illustrates a cross-sectional view showing a semiconductor apparatus according to some example embodiments of the inventive concepts. In the following embodiments, detailed descriptions of technical features overlapping with those discussed above with reference to fig. 1A, 1B, 1C, and 1D will be omitted, and differences thereof will be discussed in detail.

Referring to fig. 6, the substrate 100 may be provided to include a first region RG1 and a second region RG 2. The first area RG1 may be a memory cell area on which a DRAM device is disposed. The second region RG2 may be a peripheral circuit region or a core region.

A device isolation layer ST may be disposed on the substrate 100. The device isolation layer ST may separate the first and second regions RG1 and RG2 from each other. The device isolation layer ST may define a first active portion ACT1 on the first region RG1 of the substrate 100, and may also define a second active portion ACT2 on the second region RG2 of the substrate 100. For example, the device isolation layer ST may include a silicon oxide layer, a silicon nitride layer, or a silicon oxynitride layer.

The first area RG1 of the substrate 100 may be provided thereon with a first gate line GL1 traversing the first active portion ACT 1. The first gate line GL1 may extend in the first direction D1 and may be arranged in the second direction D2. The first gate line GL1 may be embedded in the first area RG1 of the substrate 100. The first gate line GL1 may include a conductive material. For example, the conductive material may include one or more of a doped semiconductor (doped silicon, doped germanium, etc.), a conductive metal nitride (titanium nitride, tantalum nitride, etc.), a metal (tungsten, titanium, tantalum, etc.), and a metal semiconductor compound (tungsten silicide, cobalt silicide, titanium silicide, etc.).

The first gate dielectric pattern GI1 may be interposed between the first active portion ACT1 and each of the first gate lines GL 1. For example, the first gate dielectric pattern GI1 may include a silicon oxide layer, a silicon nitride layer, or a silicon oxynitride layer.

The first cover pattern CP1 may be disposed on a top surface of each of the first gate lines GL 1. For example, the first cover pattern CP1 may include a silicon nitride layer or a silicon oxynitride layer.

The first active portion ACT1 may be provided therein with a first impurity region SD1 and a pair of second impurity regions SD 2. The pair of second impurity regions SD2 may be spaced apart from each other on both sides of the first impurity region SD1 in the second direction D2.

The first impurity region SD1 may be disposed in the first active portion ACT1 between a pair of adjacent first gate lines GL 1. The second impurity region SD2 may be disposed in the first active portion ACT1 on opposite sides of a pair of adjacent first gate lines GL 1. The second impurity regions SD2 may be spaced apart from each other on both sides of a pair of adjacent first gate lines GL1 in the second direction D2. First impurity region SD1 may have substantially the same conductivity type as that of second impurity region SD 2.

The first region RG1 of the substrate 100 may be provided thereon with a first dielectric layer 110 covering the first active portion ACT 1. The first dielectric layer 110 may include a silicon oxide layer or a silicon oxynitride layer.

The bit line BT may be disposed in the first dielectric layer 110. The bit line BT may extend in a first direction D1. The bit line BT may be electrically connected to the first impurity region SD 1. For example, the bit line BT may include one of a doped semiconductor, a conductive metal nitride, a metal, and a metal semiconductor compound. The second cover pattern CP2 may be disposed on the bit line BT. For example, the second cover pattern CP2 may include a silicon nitride layer or a silicon oxynitride layer.

The first dielectric layer 110 may be provided therein with a first contact CT1 and a landing pad LP. The landing pads LP may be disposed on the corresponding first contacts CT 1. The first contacts CT1 may be electrically connected to the corresponding second impurity regions SD 2. The first contact CT1 and the landing pad LP may comprise a conductive material such as a metal or doped silicon.

The capacitor CAP may be disposed on the first dielectric layer 110. The capacitor CAP may include a first electrode LEL1, a second electrode LEL2, and a dielectric layer DIL between the second electrode LEL2 and the first electrode LEL 1. The first electrode LEL1 may be disposed on the corresponding landing pad LP. Each of the first electrodes LEL1 is electrically connected to the second impurity region SD2 through the landing pad LP and the first contact CT 1.

Each of the first electrodes LEL1 may have a cylindrical shape (or cup shape) including a base plate section and a side wall section extending vertically from the base plate section. The floor segment and the sidewall segment of each of the first electrodes LEL1 may have substantially the same thickness.

The first electrode LEL1 can include one of a doped semiconductor, a conductive metal nitride, a metal, and a metal semiconductor compound. For example, the first electrode LEL1 may include a metal nitride layer, such as a titanium nitride (TiN) layer, a titanium silicon nitride (TiSiN) layer, a titanium aluminum nitride (TiAlN) layer, a tantalum nitride (TaN) layer, a tantalum silicon nitride (TaSiN) layer, a tantalum aluminum nitride (TaAlN) layer, and a tungsten nitride (WN) layer.

The dielectric layer DIL may be disposed to have a uniform thickness on the surface of the first electrode LEL 1. For example, the dielectric layer DIL may include a dielectric material such as HfO₂、ZrO₂、Al₂O₃、La₂O₃、Ta₂O₃And TiO₂High-k dielectric material of (1).

The second electrode LEL2 may be disposed on the dielectric layer DIL. The second electrode LEL2 may cover the first electrode LEL1 with the dielectric layer DIL interposed between the second electrode LEL2 and the first electrode LEL 1. The second electrode LEL2 may fill a portion of the cylindrical shape (or cup shape) inside the first electrode LEL 1. The second electrode LEL2 can include one of a doped semiconductor, a conductive metal nitride, a metal, and a metal semiconductor compound. For example, the second electrode LEL2 may have a structure in which a metal nitride layer and a semiconductor layer are sequentially stacked.

The second dielectric layer 120 and the third dielectric layer 130 may be sequentially stacked on the capacitor CAP. The second dielectric layer 120 may include a silicon oxide layer or a silicon oxynitride layer. The third dielectric layer 130 may include a material having an etch selectivity with respect to the second dielectric layer 120. For example, third dielectric layer 130 may include tetraethyl orthosilicate (TEOS).

The second contact CT2 may be disposed to penetrate the second dielectric layer 120 and have an electrical connection with the second electrode LEL 2. The first conductive lines ML1 may be disposed in the third dielectric layer 130. First conductive lines ML1 may extend in first direction D1. The first conductive line ML1 may be electrically connected to the capacitor CAP through the second contact CT 2. First conductive lines ML1 may have a width in second direction D2, which may decrease as the distance from substrate 100 decreases.

The second contact CT2 may include a lower segment CT2L disposed in the second dielectric layer 120 and an upper segment CT2U disposed on the lower segment CT 2L. The upper segment CT2U may be disposed in the third dielectric layer 130. The upper segment CT2U may have a width in the second direction D2 that may increase as the distance from the substrate 100 decreases. Upper section CT2U may have a top surface covered by first conductive line ML 1. Upper section CT2U may have sidewalls partially covered by first conductive lines ML 1.

The second area RG2 of the substrate 100 may be provided thereon with a second gate line GL2 traversing the second active portion ACT 2. The second gate line GL2 may extend in the first direction D1. The second gate line GL2 may include a conductive material. For example, the conductive material may include one or more of a doped semiconductor (doped silicon, doped germanium, etc.), a conductive metal nitride (titanium nitride, tantalum nitride, etc.), a metal (tungsten, titanium, tantalum, etc.), and a metal semiconductor compound (tungsten silicide, cobalt silicide, titanium silicide, etc.).

The second gate dielectric pattern GI2 may be interposed between the second active portion ACT2 and the second gate line GL 2. For example, the second gate dielectric pattern GI2 may include a silicon oxide layer, a silicon nitride layer, or a silicon oxynitride layer.

The gate spacers GS may be disposed on opposite sidewalls of the second gate line GL 2. The gate spacers GS may be spaced apart from each other on both sides of the second gate line GL2 in the second direction D2. The gate spacer GS may include a silicon oxide layer, a silicon nitride layer, or a silicon oxynitride layer.

The third cover pattern CP3 may be disposed on a top surface of the second gate line GL 2. For example, the third cover pattern CP3 may include a silicon nitride layer or a silicon oxynitride layer.

A pair of third impurity regions SD3 may be provided in the second active portion ACT 2. The pair of third impurity regions SD3 may be spaced apart from each other on both sides of the second gate line GL2 in the second direction D2. The third impurity regions SD3 may have substantially the same conductivity type as each other.

The first dielectric layer 110, the second dielectric layer 120, and the third dielectric layer 130 may be sequentially stacked on the second region RG2 of the substrate 100.

The third contact CT3 may be disposed to penetrate the first and second dielectric layers 110 and 120 and have an electrical connection with the third impurity region SD 3. The second conductive lines ML2 may be disposed in the third dielectric layer 130. Second conductive lines ML2 may extend in first direction D1. The second conductive line ML2 may be electrically connected to the third impurity region SD3 through the third contact CT 3. The second conductive lines ML2 may have a width in the second direction D2, which may decrease as the distance from the substrate 100 decreases.

The third contact CT3 may include a lower section CT3L disposed in the first and second dielectric layers 110, 120 and an upper section CT3U disposed on the lower section CT 3L. The upper segment CT3U may be disposed in the third dielectric layer 130. The upper segment CT3U may have a width in the second direction D2 that may increase as the distance from the substrate 100 decreases. Upper section CT3U may have a top surface covered by second conductive line ML 2. The upper section CT3U may have sidewalls partially covered by the second conductive lines ML 2.

According to the inventive concept, the sidewall of the upper section of the contact may be in contact with the conductive line, which may result in an improvement in interfacial resistance characteristics between the contact and the conductive line.

Although the present invention has been described in connection with some exemplary embodiments of the inventive concept illustrated in the accompanying drawings, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the technical spirit and essential features of the inventive concept. It will be apparent to those skilled in the art that various substitutions, modifications and changes may be made thereto without departing from the scope and spirit of the inventive concept.