Patent Publication Number: US-11646316-B2

Title: Integrated circuit devices and methods of manufacturing the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 17/179,469, filed Feb. 19, 2021, which claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2020-0069845, filed on Jun. 9, 2020, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     The present inventive concept relates to an integrated circuit device and a method of manufacturing the same, and more particularly, to an integrated circuit device including a fin field-effect transistor and a method of manufacturing the integrated circuit device. 
     With down-scaling of integrated circuit devices, the accuracy of the operations of integrated circuit devices as well as the fast operating speed thereof became an important consideration. Accordingly, techniques for reducing an area occupied by wirings and contacts, reliably securing a distance between wirings and contacts for electrical isolation, and increasing reliability have been developed. 
     SUMMARY 
     Embodiments of present inventive concept provide integrated circuit devices including a structure increasing the reliability of the integrated circuit devices having a device region reduced by down-scaling. 
     Embodiments of present inventive concept also provide methods of manufacturing an integrated circuit device including a structure increasing the reliability of the integrated circuit devices having a device region reduced by down-scaling. 
     According to some embodiments of the present inventive concept, provided are integrated circuit devices including a fin-type active region extending on a substrate in a first horizontal direction; a gate line extending on the fin-type active region in a second horizontal direction crossing the first horizontal direction; a source/drain region on the fin-type active region and adjacent to the gate line; and a source/drain contact pattern electrically connected to the source/drain region and including a first portion and a second portion, the first portion having a first height in a vertical direction, the second portion having a second height less than the first height in the vertical direction, wherein the source/drain contact pattern includes a metal plug in the first portion and the second portion and a conductive barrier film on sidewalls of the metal plug in the first portion and the second portion, and a first top surface of the conductive barrier film in the second portion is lower than a top surface of the metal plug in the second portion relative to the substrate. 
     According to some embodiments of the present inventive concept, provided are integrated circuit devices including a plurality of fin-type active regions extending on a substrate in a first horizontal direction to be parallel to each other; a gate line extending on the plurality of fin-type active regions in a second horizontal direction crossing the first horizontal direction; a source/drain region on the plurality of fin-type active regions and adjacent to the gate line; and a source/drain contact pattern electrically connected to the source/drain region, wherein the source/drain contact pattern includes a first portion and a second portion, the first portion has a first height in a vertical direction, and the second portion has a second height less than the first height in the vertical direction; the first portion includes a first portion of a metal plug and a first portion of a conductive barrier film on a sidewall of the first portion of the metal plug, and the second portion includes a second portion of the metal plug and a second portion of the conductive barrier film on a sidewall of the second portion of the metal plug; a first top surface of the first portion of the conductive barrier film and a second top surface of the first portion of the metal plug are coplanar with each other and are at a first vertical level; and a third top surface of the second portion of the conductive barrier film is lower than a fourth top surface of the second portion of the metal plug relative to the substrate. 
     According to some embodiments of the present inventive concept, provided are integrated circuit devices including a first fin-type active region and a second fin-type active region, the first and second fin-type active regions each extending on a substrate in a first horizontal direction to be parallel with each other and being spaced apart from each other in a second horizontal direction crossing the first horizontal direction; a gate line extending longitudinally in the second horizontal direction on the first fin-type active region and the second fin-type active region; a source/drain region on the first fin-type active region and the second fin-type active region; and a source/drain contact pattern electrically connected to the source/drain region, wherein the source/drain contact pattern includes a first portion and a second portion, the first portion overlapping the first fin-type active region in a vertical direction and having a first height in the vertical direction, and the second portion overlapping the second fin-type active region in the vertical direction, having a second height less than the first height in the vertical direction, and the source/drain contact pattern includes a metal plug and a conductive barrier film, the metal plug includes a protruding top portion in the second portion, and the conductive barrier film in the second portion is on a sidewall of the metal plug in the second portion and includes a first top surface that is lower than a top surface of the protruding top portion relative to the substrate. 
     According to some embodiments of the present inventive concept, provided are methods of manufacturing an integrated circuit device. In the methods, a fin-type active region extending on a substrate in a first horizontal direction is formed. A source/drain region is formed on the fin-type active region. A source/drain contact pattern electrically connected to the source/drain region is formed. The source/drain contact pattern includes a first portion and a second portion, the first portion having a first height in a vertical direction, the second portion having a second height less than the first height in the vertical direction. The source/drain contact pattern includes a metal plug in the first portion and the second portion and a conductive barrier film on sidewalls of the metal plug in the first portion and the second portion, and the conductive barrier film in the second portion including a first top surface lower than a top surface of the metal plug in the second portion relative to the substrate. 
     According to some embodiments of the present inventive concept, provided are methods of manufacturing an integrated circuit device. In the methods, a fin-type active region extending on a substrate in a first horizontal direction is formed. A source/drain region is formed on the fin-type active region. An insulating film on the source/drain region is formed. A source/drain contact hole is formed in the insulating film to expose the source/drain region. A source/drain contact pattern is formed in the source/drain contact hole to include a first portion and a second portion, the first portion having a first height in a vertical direction, and the second portion having a second height less than the first height in the vertical direction. The forming of the source/drain contact pattern includes forming a preliminary source/drain contact in the source/drain contact hole, the preliminary source/drain contact including a preliminary conductive barrier film and a preliminary metal plug; forming a mask pattern on a portion of the preliminary source/drain contact; and then forming a metal plug and a conductive barrier film by etching the preliminary conductive barrier film and the preliminary metal plug using the mask pattern as an etch mask. The metal plug is in the first portion and the second portion, and the conductive barrier film covers sidewalls of the metal plug in the first portion and the second portion, and the conductive barrier film in the second portion including a first top surface lower than a top surface of the metal plug in the second portion relative to the substrate. 
     According to some embodiments of the present inventive concept, methods of manufacturing an integrated circuit device are provided. In the methods, a first fin-type active region and a second fin-type active region are formed on a substrate to extend in a first horizontal direction to be parallel to each other and to be spaced apart from each other in a second horizontal direction crossing the first horizontal direction. A source/drain region is formed on the first fin-type active region and the second fin-type active region to be electrically connected to the first fin-type active region and the second fin-type active region. An insulating film is formed on the source/drain region. A source/drain contact pattern is formed to pass through the insulating film and electrically connected to the source/drain region. The source/drain contact pattern includes a first portion and a second portion, the first portion overlapping the first fin-type active region in a vertical direction and having a first height in the vertical direction, and the second portion overlapping the second fin-type active region in the vertical direction and having a second height less than the first height in the vertical direction. The forming of the source/drain contact pattern includes forming a metal plug and a conductive barrier film, the metal plug including a protruding top portion in the second portion, and the conductive barrier film on a sidewall of the metal plug in the second portion and including a first top surface lower than a topmost surface of the protruding top portion relative to the substrate. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Example embodiments of the present inventive concept will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings in which: 
         FIG.  1    is a layout of an integrated circuit device according to some embodiments of the present inventive concept; 
         FIG.  2 A  shows cross-sectional views taken along lines X 1 -X 1 ′ and X 2 -X 2 ′ in  FIG.  1   ;  FIG.  2 B  is a cross-sectional view taken along line Y 1 -Y 1 ′ in  FIG.  1   ; 
         FIGS.  3 A and  3 B  are enlarged cross-sectional views of a portion corresponding to region C 1  in  FIG.  1   , wherein  FIG.  3 A  is an enlarged cross-sectional view of region C 2 A in  FIG.  2 A , and  FIG.  3 B  is an enlarged cross-sectional view of region C 2 B in  FIG.  2 B ; 
         FIGS.  4 A and  4 B  are cross-sectional views of an integrated circuit device according to some embodiments of the present inventive concept; 
         FIGS.  5 A and  5 B  are cross-sectional views of an integrated circuit device according to some embodiments of the present inventive concept; 
         FIGS.  6 A and  6 B  are cross-sectional views of an integrated circuit device according to some embodiments of the present inventive concept; 
         FIGS.  7 A and  7 B  are cross-sectional views of an integrated circuit device according to some embodiments of the present inventive concept; 
         FIG.  8 A  is a layout of an integrated circuit device according to some embodiments of the present inventive concept;  FIG.  8 B  is a cross-sectional view taken along line X 8 -X 8 ′ in  FIG.  8 A ; 
         FIG.  9    is a cross-sectional view of an integrated circuit device according to some embodiments of the present inventive concept; 
         FIG.  10 A  is a layout of an integrated circuit device according to some embodiments of the present inventive concept;  FIG.  10 B  is a cross-sectional view taken along line X 9 -X 9 ′ in  FIG.  10 A ;  FIG.  10 C  is a cross-sectional view taken along line Y 9 -Y 9 ′ in  FIG.  10 A ; 
         FIGS.  11 A through  22 B  are cross-sectional views illustrating a method of manufacturing an integrated circuit device, according to some embodiments of the present inventive concept, wherein  FIGS.  11 A,  12 A,  13 A,  14 A,  15 A,  16 A,  17 A,  18 A,  19 A,  20 A,  21 A, and  22 A  show portions respectively corresponding to the cross-sections respectively taken along the lines X 1 -X 1 ′ and X 2 -X 2 ′ in  FIG.  1   , and  FIGS.  11 B,  12 B,  13 B,  14 B,  15 B,  16 B,  17 B,  18 B,  19 B,  20 B,  21 B, and  22 B  show a portion corresponding to the cross-section taken along the line Y 1 -Y 1 ′ in  FIG.  1   ; 
         FIGS.  23 A through  23 D  are cross-sectional views illustrating a method of manufacturing an integrated circuit device, according to some embodiments of the present inventive concept; 
         FIGS.  24 A and  24 B  are cross-sectional views illustrating a method of manufacturing an integrated circuit device, according to some embodiments of the present inventive concept; and 
         FIGS.  25 A through  31    are cross-sectional views illustrating a method of manufacturing an integrated circuit device, according to some embodiments of the present inventive concept, wherein  FIGS.  25 A,  26 A,  27 A,  28 A,  29 A,  30 A, and  31    show a portion corresponding to the cross-section taken along the line X 9 -X 9 ′ in  FIG.  10 A , and  FIGS.  25 B,  26 B,  27 B,  28 B,  29 B, and  30 B  show a portion corresponding to the cross-section taken along the line Y 9 -Y 9 ′ in  FIG.  10 A . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, example embodiments of the present inventive concept will be described in detail with reference to the accompanying drawings. In the drawings, like reference numbers and characters refer to like elements, and redundant descriptions thereof may be omitted. 
       FIG.  1    is a layout of an integrated circuit device  100  according to some embodiments of the present inventive concept.  FIG.  2 A  show cross-sectional views taken along lines X 1 -X 1 ′ and X 2 -X 2 ′ in  FIG.  1   , and  FIG.  2 B  is a cross-sectional view taken along line Y 1 -Y 1 ′ in  FIG.  1   .  FIGS.  3 A and  3 B  are enlarged cross-sectional views of a portion corresponding to region Cl in  FIG.  1   , wherein  FIG.  3 A  is an enlarged cross-sectional view of region C 2 A in  FIG.  2 A , and  FIG.  3 B  is an enlarged cross-sectional view of region C 2 B in  FIG.  2 B . 
     Referring to  FIGS.  1  through  3 B , the integrated circuit device  100  includes a logic cell LC formed in a region defined by a cell boundary BN on a substrate  110 . The logic cell LC may include a fin field-effect transistor (FinFET). 
     The substrate  110  has a main surface  110 M extending in a horizontal direction (e.g., an XY-plane direction). The substrate  110  may include a semiconductor material such as Si or Ge or a compound semiconductor material such as SiGe, SiC, GaAs, InAs, or InP. The substrate  110  may include a conductive region, e.g., an impurity-doped well or an impurity-doped structure. 
     The logic cell LC includes a first device region RX 1  and a second device region RX 2 . A plurality of fin-type active regions FA protruding from the substrate  110  may be formed in each of the first device region RX 1  and the second device region RX 2 . A device isolation region DTA may be between the first device region RX 1  and the second device region RX 2 . 
     The fin-type active regions FA may extend in a width direction of the logic cell LC, i.e., a first horizontal direction (e.g., an X direction), to be parallel to each other. As shown in  FIG.  2 B , an isolation film  112  may be formed in the substrate  110  among the fin-type active regions FA, and an isolation insulating film  114  may be formed in the substrate  110  in the device isolation region DTA. Each of the isolation film  112  and the isolation insulating film  114  may include, for example, an oxide film. The fin-type active regions FA may protrude from the isolation film  112  to have a fin shape in the first device region RX 1  and the second device region RX 2 . 
     A plurality of gate insulating films  132  and a plurality of gate lines GL are formed on the substrate  110  to extend in a height direction of the logic cell LC, i.e., a second horizontal direction (e.g., a Y direction), crossing the fin-type active regions FA. The gate insulating films  132  and the gate lines GL may cover the top surface and both sidewalls of each of the fin-type active regions FA, the top surface of the isolation film  112 , and the top surface of the isolation insulating film  114 . “An element A covers a surface of an element B” (or similar language) as used herein may mean that the element A is on and overlaps the surface of the element B and does not necessarily mean that the element A covers the surface of the element B entirely. 
     A plurality of metal-oxide semiconductor (MOS) transistors may be formed along the gate lines GL in the first device region RX 1  and the second device region RX 2 . Each of the MOS transistors may have a three-dimensional ( 3 D) structure, in which a channel is formed on the top surface and both sidewalls of each of the fin-type active regions FA. 
     A dummy gate line DGL may extend along the cell boundary BN in the second horizontal direction (the Y direction). The dummy gate line DGL may include the same material as the gate lines GL but may function as an electrical isolation region between the logic cell LC and another neighboring logic cell by maintaining an electrical floating state during the operation of the integrated circuit device  100 . The gate lines GL and a plurality of dummy gate lines DGL may have the same width in the first horizontal direction (the X direction) and may be arranged at a certain pitch in the first horizontal direction (the X direction). 
     The gate insulating films  132  may include, for example, a silicon oxide film, a high-k dielectric film, or a combination thereof. The high-k dielectric film may include a material having a higher dielectric constant than a silicon oxide film. The high-k dielectric film may include, for example, metal oxide or metal oxynitride. An interface film (not shown) may be between a fin-type active region FA and a gate insulating film  132 . The interface film may include, for example, an oxide film, a nitride film, or an oxynitride film. 
     The gate lines GL and the dummy gate lines DGL may have a structure, in which a metal nitride layer, a metal layer, a conductive capping layer, and a gap-fill metal film are sequentially stacked. The metal nitride layer and the metal layer may include at least one metal selected from Ti, Ta, W, Ru, Nb, Mo, and Hf. The gap-fill metal film may include a W film or an A 1  film. The gate lines GL and the dummy gate lines DGL may include a work function metal layer. The work function metal layer may include at least one metal selected from Ti, W, Ru, Nb, Mo, Hf, Ni, Co, Pt, Yb, Tb, Dy, Er, and Pd. In some embodiments, the gate lines GL and the dummy gate lines DGL may include a stack structure of TiAlC/TiN/W, TiN/TaN/TiAlC/TiN/W, or TiN/TaN/TiN/TiAlC/TiN/W but are not limited thereto. 
     A plurality of insulating spacers  120  may cover both sidewalls of the gate lines GL and both sidewalls of the dummy gate lines DGL. Each of the insulating spacers  120  may have a line shape extending in a length direction (the Y direction) of the logic cell LC. The insulating spacers  120  may include, for example, a silicon nitride film, a SiOCN film, a SiCN film, or a combination thereof but are not limited thereto. 
     The top surface of each of the gate lines GL, the gate insulating films  132 , the insulating spacers  120 , and the dummy gate lines DGL may be covered with an insulating capping line  140 . A plurality of insulating capping lines  140  may include, for example, a silicon nitride film. 
     A plurality of recess regions RR may be formed in top surfaces of the fin-type active regions FA at sides of each of the gate lines GL, respectively, and a plurality of source/drain regions SD may be formed in the recess regions RR, respectively. Each of the source/drain regions SD may be between adjacent gate lines GL. A gate line GL may be separated from a source/drain region SD with a gate insulating film  132  and an insulating spacer  120  between the gate line GL and the source/drain region SD. A plurality of source/drain regions SD may include, for example, a semiconductor epitaxial layer epitaxially grown on a plurality of recess regions RR in a fin-type active region FA or a combination of semiconductor epitaxial layers. The source/drain regions SD may include, for example, an epitaxially grown Si layer, an epitaxially grown SiC layer, or an epitaxially grown SiGe layer. An intergate insulating film  128  may include, for example, a silicon oxide film. In example embodiments, the source/drain regions SD may be covered with an insulating liner (not shown). The insulating liner may conformally cover the surface of each of the source/drain regions SD. The insulating liner may include, for example, SiN, SiCN, SiBN, SiON, SiOCN, SiBCN, SiOC, SiO 2 , or a combination thereof. 
     In example embodiments, the first device region RX 1  may correspond to an N-channel MOS (NMOS) transistor region, and the second device region RX 2  may correspond to a P-channel MOS (PMOS) transistor region. In this case, a plurality of source/drain regions SD in the first device region RX 1  may include an epitaxially grown Si layer or an epitaxially grown SiC layer, and a plurality of source/drain regions SD in the second device region RX 2  may include a plurality of epitaxially grown SiGe layers. As shown in  FIG.  2 B , the source/drain regions SD in the first device region RX 1  may have a different shape and size than the source/drain regions SD in the second device region RX 2 . However, embodiments are not limited thereto, and a plurality of source/drain regions SD may have various shapes and sizes in the first device region RX 1  and the second device region RX 2 . 
     A plurality of source/drain contact patterns CAP may be formed on the source/drain regions SD. The source/drain regions SD may be connected to a conductive line (not shown) thereabove through the source/drain contact patterns CAP. The source/drain contact patterns CAP may include a conductive barrier film  154  and a metal plug  156 . The conductive barrier film  154  may cover the sidewall and bottom surface of the metal plug  156 . A metal silicide film  152  may be formed between a source/drain region SD and a source/drain contact pattern CAP. “An element A is connected to an element B” (or similar language) as used herein may mean that the element A is electrically connected to the element B or the element A physically contacts the element B. 
     In example embodiments, the metal silicide film  152  may include, for example, Ti, W, Ru, Nb, Mo, Hf, Ni, Co, Pt, Yb, Tb, Dy, Er, or Pd. For example, the metal silicide film  152  may include titanium silicide. The conductive barrier film  154  may include, for example, Ti, Ta, TiN, TaN, or a combination thereof, and the metal plug  156  may include, for example, W, Co, Cu, Ru, Mn, or a combination thereof. 
     The sidewall of each of the source/drain contact patterns CAP may be covered with a contact insulating spacer  150 . In example embodiments, the contact insulating spacer  150  may include, for example, SiCN, SiCON, silicon nitride (SiN), or a combination thereof but is not limited thereto. 
     The source/drain contact patterns CAP may have different heights according to the positions thereof. Each of the source/drain contact patterns CAP may include a first segment S 1  and a second segment S 2 , which respectively have different heights in a vertical direction (a Z direction) and are integrally connected to each other. As used herein, the term “segment” may be interchangeable with the term “portion.” 
     As shown in  FIG.  3 B , the first segment S 1  of a source/drain contact pattern CAP above a fin-type active region FA may have a first height H 1  in the vertical direction (the Z direction), and the second segment S 2  of the source/drain contact pattern CAP may have a second height H 2  in the vertical direction (the Z direction), the second height H 2  being less than the first height H 1 . 
     In each source/drain contact pattern CAP, the conductive barrier film  154  and the metal plug  156  may extend across the first segment S 1  and the second segment S 2  to be included in the first segment S 1  and the second segment S 2 . 
     In the first segment S 1  of each source/drain contact pattern CAP, a top surface of the conductive barrier film  154  may be coplanar with a top surface of the metal plug  156  at a vertical level LV 1 . In the specification, the term “level” refers to a distance from the main surface  110 M of the substrate  110  in the vertical direction (the Z direction). 
     In the second segment S 2  of each source/drain contact pattern CAP, a vertical level LV 2  of a topmost surface of the conductive barrier film  154  is lower than a vertical level LV 3  of a topmost surface of the metal plug  156 . A height difference DH 1  between the vertical level LV 3  of the topmost surface of the metal plug  156  and the vertical level LV 2  of the topmost surface of the conductive barrier film  154  in the second segment S 2  may be about 1 nm to about 5 nm, for example, about 2 nm to about 3 nm. As used herein, “a vertical level X of a surface A is lower than a vertical level Y of a surface B” (or similar language) may mean that the surface A is lower than the surface B in a vertical direction relative to a substrate, and the substrate is thus closer to the surface A than the surface B in the vertical direction. 
     The vertical level LV 1  of a topmost surface of the first segment S 1  may be higher than a vertical level of a topmost surface of the gate line GL in the vertical direction (the Z direction), and the vertical level LV 2  of the topmost surface of the conductive barrier film  154  in the second segment S 2  and the vertical level LV 3  of the topmost surface of the metal plug  156  in the second segment S 2  may be lower than the vertical level of the topmost surface of the gate line GL. In other words, a distance from the main surface  110 M of the substrate  110  to the topmost surface of the first segment S 1  may be greater than a distance from the main surface  110 M of the substrate  110  to the topmost surface of each of the gate lines GL in the vertical direction (the Z direction), and a distance from the main surface  110 M of the substrate  110  to the topmost surface of the second segment S 2  may be less than a distance from the main surface  110 M of the substrate  110  to the topmost surface of each of the gate lines GL in the vertical direction (the Z direction). However, embodiments are not limited thereto. For example, the topmost surface of each of the first and second segments S 1  and S 2  may be higher than the topmost surface of each of the gate lines GL. As used herein, “a vertical level X of a surface A is higher than a vertical level Y of a surface B” (or similar language) may mean that the surface A is higher than the surface B in a vertical direction relative to a substrate, and the substrate is thus closer to the surface B than the surface A in the vertical direction. 
     In the second segment S 2  of each source/drain contact pattern CAP, the metal plug  156  may include a protruding top portion  156 P at a level higher than the vertical level LV 2  of the topmost surface of the conductive barrier film  154  in the second segment S 2 . In the second segment S 2  of each source/drain contact pattern CAP, a sidewall of the protruding top portion  156 P of the metal plug  156  may not be covered with the conductive barrier film  154 . The protruding top portion  156 P may protrude beyond the topmost surface of the conductive barrier film  154  in the second segment S 2  as illustrated in  FIGS.  3 A and  3 B . 
     The protruding top portion  156 P may have a flat top surface (e.g., a substantially planar top surface). In example embodiments, a topmost surface of the protruding top portion  156 P may extend substantially evenly in a direction parallel to the main surface  110 M of the substrate  110 . However, embodiments are not limited thereto, and the shape of the protruding top portion  156 P may be variously changed. Specific examples of various shapes of the protruding top portion  156 P will be described with reference to  FIGS.  5 A through  7 B  below. 
     The insulating capping lines  140  may have different thicknesses at different positions. For example, as shown in  FIG.  2 A , a portion of the insulating capping lines  140 , which is between two adjacent first segments S 1 , may be relatively thick, and a portion of the insulating capping lines  140 , which is between two adjacent second segments S 2 , may be relatively thin. A portion of an insulating capping line  140  between the first segment S 1  of one source/drain contact pattern CAP and the second segment S 2  of another source/drain contact pattern CAP may have a thickness, which may be variable and decrease from the first segment S 1  toward the second segment S 2  in the first horizontal direction (the X direction). 
     The integrated circuit device  100  may include a buried insulating film  170 , which covers the second segment S 2  of each of a plurality of source/drain contact patterns CAP, the gate lines GL, and a plurality of insulating capping lines  140 , and an insulating structure  180  covering a top surface of the buried insulating film  170 . 
     The buried insulating film  170  may be in contact with the top surface of each of a plurality of second segments S 2  and the top surface of each of the insulating capping lines  140 . The buried insulating film  170  may include a main buried portion  170 M and a buried protrusion  170 P. The main buried portion  170 M covers the top surface of the metal plug  156  included in each of the second segments S 2 , portions of a plurality of contact insulating spacers  150  adjacent to the second segments S 2 , and the insulating capping lines  140 . The buried protrusion  170 P protrudes from the main buried portion  170 M toward the substrate  110 . The buried protrusion  170 P may be on the second segment S 2  of each of the source/drain contact patterns CAP to be in contact with the top surface of the conductive barrier film  154 . The buried protrusion  170 P may also be in contact with the sidewall of the protruding top portion  156 P of the metal plug  156  and a sidewall of the contact insulating spacer  150 . The buried protrusion  170 P may fill a space (e.g., an inner space of a lower recess LR illustrated in  FIGS.  19 A and  19 B ), which is defined by the topmost surface of the conductive barrier film  154 , the sidewall of the protruding top portion  156 P of the metal plug  156 , and the sidewall of the contact insulating spacer  150 . 
     The buried insulating film  170  may have a planarized top surface. The buried insulating film  170  may include a portion filling a space above the second segment S 2  of each of the source/drain contact patterns CAP among the gate lines GL. The top surface of the buried insulating film  170  may be coplanar with the topmost surfaces of the conductive barrier film  154  and the metal plug  156 , which are included in the first segment S 1  of each of the source/drain contact patterns CAP, and may be substantially at the vertical level LV 1 . The buried insulating film  170  may include, for example, a silicon oxide film, SiOC, SiOCN, SiON, SiCN, SiN, or a combination thereof but is not limited thereto. 
     The insulating structure  180  may include an etch stop film  182  and an interlayer insulating film  184 , which are sequentially stacked on the buried insulating film  170 . The bottom surface of the etch stop film  182  may be in contact with the topmost surface of the buried insulating film  170 . The etch stop film  182  may include, for example, silicon carbide (SiC), SiN, nitrogen-doped silicon carbide (SiC:N), SiOC, AlN, AlON, AlO, AlOC, or a combination thereof. The interlayer insulating film  184  may include, for example, an oxide film, a nitride film, an ultra low-k (ULK) film having an ultra low dielectric constant K of about 2.2 to about 2.4, or a combination thereof. For example, the interlayer insulating film  184  may include a tetraethylorthosilicate (TEOS) film, a high density plasma (HDP) film, a boro-phospho-silicate glass (BPSG) film, a flowable chemical vapor deposition (FCVD) oxide film, a SiON film, a SiN film, a SiOC film, a SiCOH film, or a combination thereof. 
     A plurality of via contacts CAV may be respectively formed on the source/drain contact patterns CAP. Each of the via contacts CAV may pass through the insulating structure  180  and be in contact with the top surface of the first segment S 1  of a source/drain contact pattern CAP. 
     A plurality of gate contacts CB may be respectively formed on the gate lines GL. Each of the gate contacts CB may pass through the insulating structure  180 , the buried insulating film  170 , and an insulating capping line  140  and may be connected to a gate line GL. Each gate contact CB may pass through a relatively thin portion of the insulating capping line  140  and be in contact with the top surface of the gate line GL. 
     Each of some gate contacts CB may be in contact with the gate line GL in a location adjacent to the second segment S 2  of the source/drain contact pattern CAP. In this case, as shown in  FIGS.  2 A and  3 A , the buried protrusion  170 P of the buried insulating film  170  may be between the gate line GL and the second segment S 2  of the source/drain contact pattern CAP, which are adjacent to each other in the first horizontal direction (the X direction). In other words, a gate contact CB and the second segment S 2  of the source/drain contact pattern CAP may be separated from each other in the first horizontal direction (the X direction) with the buried protrusion  170 P of the buried insulating film  170  therebetween. Accordingly, a separation distance from the conductive barrier film  154  and the metal plug  156 , which form the second segment S 2 , to the gate line GL may be secured at least by the buried protrusion  170 P. Therefore, even when the gate contact CB and the second segment S 2  of the source/drain contact pattern CAP are formed to be adjacent to each other, an insulation margin between the gate contact CB and the source/drain contact pattern CAP may be secured, thereby reducing or preventing an undesirable short-circuit between the gate contact CB and the source/drain contact pattern CAP. 
     Each of the via contacts CAV and the gate contacts CB may include a buried metal film and a conductive barrier film surrounding the buried metal film. The buried metal film may include, for example, Co, Cu, W, Ru, Mn, or a combination thereof, and the conductive barrier film may include, for example, Ti, Ta, TiN, TaN, or a combination thereof. Sidewalls of each of the via contacts CAV and the gate contacts CB may be covered with an insulating liner (not shown). The insulating liner may include, for example, a silicon nitride film but is not limited thereto. “An element A surrounds an element B” (or similar language) as used herein may mean that the element A is on and partially surrounds the element B and does not necessarily mean that the element A completely surrounds the surface of the element B entirely. 
     In the logic cell LC, a ground line VSS may be connected to fin-type active regions FA in the first device region RX 1  through some of the source/drain contact patterns CAP, and a power supply line VDD may be connected to fin-type active regions FA in the second device region RX 2  through others of the source/drain contact patterns CAP. The ground line VSS and the power supply line VDD may be formed at a level higher than the top surface of each of the source/drain contact patterns CAP and the gate contacts CB. Each of the ground line VSS and the power supply line VDD may include a conductive barrier film and a wiring conductive layer. The conductive barrier film may include, for example, Ti, Ta, TiN, TaN, or a combination thereof. The wiring conductive layer may include, for example, Co, Cu, W, an alloy thereof, or a combination thereof. 
       FIGS.  4 A and  4 B  are cross-sectional views of an integrated circuit device  200  according to some embodiments of the present inventive concept.  FIG.  4 A  shows cross-sectional views of the integrated circuit device  200  taken along the line X 1 -X 1 ′ and the line X 2 -X 2 ′ in  FIG.  1   , and  FIG.  4 B  shows a cross-section view of the integrated circuit device  200  taken along the line Y 1 -Y 1 ′ in  FIG.  1   . 
     Referring to  FIGS.  4 A and  4 B , the integrated circuit device  200  may be substantially the same as or similar to the integrated circuit device  100  described with reference to  FIGS.  1  through  3 B . However, the integrated circuit device  200  includes a plurality of conductive lines ML, which extend on the via contacts CAV in a direction crossing a plurality of gate lines GL. 
     Some of the conductive lines ML may each be connected to a source/drain region SD through a via contact CAV and a source/drain contact pattern CAP. Although not shown, others of the conductive lines ML may each be connected to a gate line GL through a gate contact CB. 
     The conductive lines ML may be formed at the same level as the ground line VSS and the power supply line VDD on the substrate  110 . The conductive lines ML may include a plurality of unidirectional wiring layers extending in the first horizontal direction (the X direction) to be parallel to each other. Each of the conductive lines ML may include a conductive barrier film and a wiring conductive layer. The conductive barrier film may include, for example, Ti, Ta, TiN, TaN, or a combination thereof. The wiring conductive layer may include, for example, Co, Cu, W, an alloy thereof, or a combination thereof. 
       FIGS.  5 A and  5 B  are cross-sectional views of an integrated circuit device  300  according to some embodiments of the present inventive concept. In detail,  FIG.  5 A  is an enlarged cross-sectional view of the region Cl in  FIG.  1    taken along the line X 1 -X 1 ′ in  FIG.  1   , and  FIG.  5 B  is an enlarged cross-sectional view of the region Cl in  FIG.  1    taken along the line Y 1 -Y 1 ′ in  FIG.  1   . 
     Referring to  FIGS.  5 A and  5 B , the integrated circuit device  300  may be substantially the same as or similar to the integrated circuit device  100  described with reference to  FIGS.  1  through  3 B . However, a source/drain contact pattern CAP of the integrated circuit device  300  includes a metal plug  356  instead of the metal plug  156 . The metal plug  356  may include a protruding top portion  356 P at a higher level than the conductive barrier film  154  in the second segment S 2  of the source/drain contact pattern CAP. The protruding top portion  356 P may have a rounded corner  356 C in an outer edge thereof. A top surface portion  356 T substantially in the middle of the protruding top portion  356 P in the first horizontal direction (the X direction) may extend substantially evenly in a direction parallel to the main surface  110 M of the substrate  110 . The detailed configuration of the metal plug  356  is substantially the same as or similar to that of the metal plug  156  of the integrated circuit device  100  described with reference to  FIGS.  1  through  3 B . 
       FIGS.  6 A and  6 B  are cross-sectional views of an integrated circuit device  400  according to some embodiments of the present inventive concept. In detail,  FIG.  6 A  is an enlarged cross-sectional view of the region C 1  in  FIG.  1    taken along the line X 1 -X 1 ′ in  FIG.  1   , and  FIG.  6 B  is an enlarged cross-sectional view of the region Cl in  FIG.  1    taken along the line Y 1 -Y 1 ′ in  FIG.  1   . 
     Referring to  FIGS.  6 A and  6 B , the integrated circuit device  400  may be substantially the same as or similar to the integrated circuit device  100  described with reference to  FIGS.  1  through  3 B . However, the source/drain contact pattern CAP of the integrated circuit device  400  includes a metal plug  456  instead of the metal plug  156 . The metal plug  456  may include a protruding top portion  456 P at a higher level than the conductive barrier film  154  in the second segment S 2  of the source/drain contact pattern CAP. The protruding top portion  456 P may have a top surface portion  456 T, which bulges in a direction away from the substrate  110 . The top surface portion  456 T of the protruding top portion  456 P may extend not evenly but in a curved shape in the first horizontal direction (the X direction). The protruding top portion  456 P may have a rounded corner  456 C in an outer edge thereof in the second horizontal direction (the Y direction). The detailed configuration of the metal plug  456  may be substantially the same as or similar to that of the metal plug  156  of the integrated circuit device  100  described with reference to  FIGS.  1  through  3 B . 
       FIGS.  7 A and  7 B  are cross-sectional views of an integrated circuit device  500  according to some embodiments of the present inventive concept. In detail,  FIG.  7 A  is an enlarged cross-sectional view of the region Cl in  FIG.  1    taken along the line Xl-X 1 ′ in  FIG.  1   , and  FIG.  7 B  is an enlarged cross-sectional view of the region C 1  in  FIG.  1    taken along the line Y 1 -Y 1 ′ in  FIG.  1   . 
     Referring to  FIGS.  7 A and  7 B , the integrated circuit device  500  may be substantially the same as or similar to the integrated circuit device  100  described with reference to  FIGS.  1    through  3 B. However, the source/drain contact pattern CAP of the integrated circuit device  500  includes a metal plug  556  instead of the metal plug  156 . The metal plug  556  may include a protruding top portion  556 P at a higher level than the conductive barrier film  154  in the second segment S 2  of the source/drain contact pattern CAP. The protruding top portion  556 P may have a double-humped protrusion, which bulges in a direction away from the substrate  110 . 
     In detail, the protruding top portion  556 P may include a double-humped protrusion, which includes a first hump T 1  and a second hump T 2 , which bulge in the direction away from the substrate  110 . An indentation  556 D may be between the first hump T 1  and the second hump T 2 . Opposite sidewalls of the first hump T 1  of the protruding top portion  556 P may be symmetric or asymmetric with respect to a first peak P 1 . Opposite sidewalls of the second hump T 2  may be symmetric or asymmetric with respect to a second peak P 2 . A level of the first peak P 1  may be equal or similar to a level of the second peak P 2  in the vertical direction (the Z direction). In some embodiments, the first peak P 1  and the second peak P 2  may be equidistant from the substrate  110 . 
     The protruding top portion  556 P may have a rounded corner  556 C in an outer edge in the second horizontal direction (the Y direction). The indentation  556 D of the protruding top portion  556 P may extend substantially evenly in the second horizontal direction (the Y direction). The detailed configuration of the metal plug  556  is substantially the same as that of the metal plug  156  of the integrated circuit device  100  described with reference to  FIGS.  1  through  3 B . 
     In the integrated circuit devices  300 ,  400 , and  500  illustrated in  FIGS.  5 A through  7 B , the metal plugs  356 ,  456 , and  556  of the second segment S 2  of the source/drain contact pattern CAP may respectively include the protruding top portions  356 P,  456 P, and  556 P at a higher level than the conductive barrier film  154  in the second segment S 2 , each of the protruding top portions  356 P,  456 P, and  556 P may include the rounded corner  356 C,  456 C, or  556 C in the outer edge thereof, the top surface portions  356 T,  456 T, and  556 T that may be flat (e.g., substantially planar), may bulge, or may include a double-humped protrusion including the first hump Ti and the second hump T 2 . Accordingly, even when each of some gate contacts CB is arranged to be adjacent to the second segment S 2  of the source/drain contact pattern CAP, a separation distance between the second segment S 2  of the source/drain contact pattern CAP and an adjacent gate contact CB in the first horizontal direction (the X direction) may be sufficiently secured. Therefore, even when the gate contact CB and the second segment S 2  of the source/drain contact pattern CAP are arranged to be adjacent to each other, an insulation margin between the gate contact CB and the source/drain contact pattern CAP may be more easily secured, thereby reducing or preventing an undesirable short-circuit between the gate contact CB and the source/drain contact pattern CAP. 
       FIGS.  8 A and  8 B  are diagrams of an integrated circuit device  600  according to some embodiments of the present inventive concept, wherein  FIG.  8 A  is a layout of the integrated circuit device  600 , and  FIG.  8 B  is a cross-sectional view taken along line X 8 -X 8 ′ in  FIG.  8 A . In  FIGS.  1  through  3 B  and  FIGS.  8 A and  8 B , like reference numerals denote like elements, and detailed descriptions thereof may be omitted. The integrated circuit device  600  illustrated in  FIGS.  8 A and  8 B  may include an SRAM array including a plurality of SRAM cells arranged in a matrix on the substrate  110 . 
     Referring to  FIGS.  8 A and  8 B , the integrated circuit device  600  includes a plurality of fin-type active regions FA, which extend in the first horizontal direction (the X direction) to be parallel to each other, and a plurality of gate lines GL, which extend on the fin-type active regions FA in the second horizontal direction (the Y direction) to be parallel to each other. Transistors may be formed at respective intersections between the fin-type active regions FA and the gate lines GL. The integrated circuit device  600  may include a plurality of shared contacts SC each being connected to a gate line GL and a source/drain region SD. 
     In the integrated circuit device  600 , each of the source/drain contact patterns CAP may include the conductive barrier film  154  and the metal plug  156 . Each of the source/drain contact patterns CAP may include the first segment S 1  and the second segment S 2 , which respectively have different heights in the vertical direction (the Z direction) and are integrally connected to each other. In each of the source/drain contact patterns CAP, the conductive barrier film  154  and the metal plug  156  may extend across the first segment S 1  and the second segment S 2  to be included in the first segment S 1  and the second segment S 2 . 
     In the first segment S 1  of each of the source/drain contact patterns CAP, the top surface of the conductive barrier film  154  may be coplanar with the top surface of the metal plug  156  at a vertical level LV 61 . In the second segment S 2  of each of the source/drain contact patterns CAP, a vertical level LV 62  of the topmost surface of the conductive barrier film  154  is lower than a vertical level LV 63  of the topmost surface of the metal plug  156 . A height difference between the vertical level LV 63  of the topmost surface of the metal plug  156  and the vertical level LV 62  of the topmost surface of the conductive barrier film  154  in the second segment S 2  may be about 1 nm to about 5 nm, for example, about 2 nm to about 3 nm. 
     In the second segment S 2  of each of the source/drain contact patterns CAP, the metal plug  156  may include a protruding top portion  656 P at a level higher than the vertical level LV 62  of the topmost surface of the conductive barrier film  154 . In the second segment S 2  of each of the source/drain contact patterns CAP, a sidewall of the protruding top portion  656 P of the metal plug  156  may not be covered with the conductive barrier film  154 . 
     Similar to the protruding top portion  156 P illustrated in  FIGS.  3 A and  3 B , the protruding top portion  656 P may have a flat top surface (e.g., a substantially planar top surface). However, embodiments are not limited thereto. For example, the metal plug  156  of the integrated circuit device  600  may include, instead of the protruding top portion  656 P, a protruding top portion having a shape the same as or similar to one of the protruding top portions  356 P,  456 P, and  556 P illustrated in  FIGS.  5 A through  7 B . 
     The buried insulating film  170  may cover the top surface of the second segment S 2  of each of the source/drain contact patterns CAP and the top surface of the insulating capping line  140 . The buried insulating film  170  may include the main buried portion  170 M and the buried protrusion  170 P protruding from the main buried portion  170 M toward the substrate  110 . The main buried portion  170 M may be in contact with the top surface of the metal plug  156  included in each of a plurality of second segments S 2 , a portion of the intergate insulating film  128 , and a plurality of insulating capping lines  140 . The buried protrusion  170 P may be on the second segment S 2  of each of the source/drain contact patterns CAP to be in contact with the topmost surface of the conductive barrier film  154 . The buried protrusion  170 P may also be in contact with the sidewall of the protruding top portion  656 P of the metal plug  156 . The buried protrusion  170 P may fill a space, which is defined by the topmost surface of the conductive barrier film  154  of the second segment S 2 , the sidewall of the protruding top portion  656 P of the metal plug  156 , and the contact insulating spacer  150 . 
     The buried insulating film  170  may have a planarized top surface. The buried insulating film  170  may include a portion filling a space above the second segment S 2  of each of the source/drain contact patterns CAP among the gate lines GL. The top surface of the buried insulating film  170  may be coplanar with the topmost surfaces of the conductive barrier film  154  and the metal plug  156 , which are included in the first segment S 1  of each of the source/drain contact patterns CAP, may be substantially at the vertical level LV 61 . 
     The integrated circuit device  600  includes the metal plug  156 , which includes the protruding top portion  656 P in the second segment S 2  of a source/drain contact pattern CAP. The sidewall of the protruding top portion  656 P may be covered with the buried protrusion  170 P of the buried insulating film  170 . Accordingly, a separation distance from the conductive barrier film  154  and the metal plug  156 , which form the second segment S 2 , to another conductive region adjacent to the second segment S 2  may be secured at least by the buried protrusion  170 P. Therefore, an insulation margin between the second segment S 2  of the source/drain contact pattern CAP and an adjacent conductive region may be secured, thereby reducing or preventing an undesirable short-circuit between the second segment S 2  and the adjacent conductive region and increasing the reliability of the integrated circuit device  600 . 
       FIG.  9    is a cross-sectional view of an integrated circuit device  700  according to some embodiments of the present inventive concept.  FIG.  9    illustrates an enlarged cross-sectional view of a portion corresponding to region C 9  in  FIG.  8 B . 
     Referring to  FIG.  9   , the integrated circuit device  700  may be substantially the same as or similar to the integrated circuit device  600  described with reference to  FIGS.  8 A and  8 B . However, the integrated circuit device  700  includes a metal plug  756  instead of the metal plug  156  in the source/drain contact pattern CAP. The metal plug  756  may include a protruding top portion  756 P at a higher level than the conductive barrier film  154  in the second segment S 2  of the source/drain contact pattern CAP. The protruding top portion  756 P may have a rounded corner  756 C in an outer edge. A top surface portion  756 T substantially in the middle of the protruding top portion  756 P in the first horizontal direction (the X direction) may extend substantially evenly in a direction parallel to the main surface  110 M of the substrate  110 . However, embodiments are not limited thereto. For example, the protruding top portion  756 P may have a bulging curved shape like the protruding top portion  456 P described with reference to  FIGS.  6 A and  6 B . In another example, the protruding top portion  756 P may include a double-humped protrusion, which bulges in a direction away from the substrate  110 , like the protruding top portion  556 P described with reference to  FIGS.  7 A and  7 B . The detailed configuration of the metal plug  756  may be substantially the same as or similar to that of the metal plug  156  of the integrated circuit device  100  described with reference to  FIGS.  1  through  3 B . 
       FIGS.  10 A through  10 C  are diagrams of an integrated circuit device  900  according to some embodiments of the present inventive concept, wherein  FIG.  10 A  is a layout of the integrated circuit device  900 ,  FIG.  10 B  is a cross-sectional view taken along line X 9 -X 9 ′ in  FIG.  10 A , and  FIG.  10 C  is a cross-sectional view taken along line Y 9 -Y 9 ′ in  FIG.  10 A . 
     Referring to  FIGS.  10 A through  10 C , the integrated circuit device  900  includes a plurality of fin-type active regions F 9 , which protrude from a substrate  902  and extend (e.g., extend longitudinally) in the first horizontal direction (e.g., the X direction), and a plurality of nanosheet stacks NSS, each of which is separated from the underlying fin-type active region F 9  in the vertical direction (the Z direction) and faces a top surface FT of the fin-type active region F 9 . In this specification, the term “nanosheet” refers to a conductive structure having a cross-section substantially perpendicular to a direction in which current flows. It will be understood that the nanosheet includes a nanowire. 
     A trench T 9  defining a plurality of fin-type active regions F 9  may be formed in the substrate  902  and filled with an isolation film  912 . The substrate  902 , the fin-type active regions F 9 , and the isolation film  912  may be the same as or similar to the substrate  110 , the fin-type active regions FA, and the isolation film  112 , which are illustrated in  FIGS.  2 A and  2 B , respectively. 
     A plurality of gate lines  960  extend on the fin-type active regions F 9  in the second horizontal direction (the Y direction). Each of the nanosheet stacks NSS may be above the top surface FT of one of the fin-type active regions F 9  at an intersection between one of the fin-type active regions F 9  and one of the gate lines  960 , may face the top surface FT of one of the fin-type active regions F 9 , and may be at a position separated from one of the fin-type active regions F 9 . A plurality of nanosheet transistors may be formed at respective intersections between the fin-type active regions F 9  and the gate lines  960  on the substrate  902 . 
     Each of the nanosheet stacks NSS may include a plurality of nanosheets, which overlap each other in the vertical direction (the Z direction) above the top surface FT of one of the fin-type active regions F 9 . The nanosheets may include a first nanosheet N 1 , a second nanosheet N 2 , and a third nanosheet N 3 , which respectively have different vertical distances from the top surface FT of each of the fin-type active regions F 9 . As used herein, “an element A overlaps an element B in a vertical direction” (or similar language) may mean that at least one vertical line intersecting both the elements A and B exists. 
     Although  FIG.  10 A  show the nanosheet stacks NSS having a rectangular shape, embodiments are not limited thereto. The nanosheet stacks NSS may have various shapes in a plan view according to shapes of the fin-type active regions F 9  and the gate lines  960 . Further, although  FIGS.  10 A,  10 B, and  10 C  show that a plurality of nanosheet stacks NSS and a plurality of gate lines  960  are formed on one fin-type active region F 9  and the nanosheet stacks NSS are arranged on the fin-type active region F 9  along the first horizontal direction (the X direction), the present inventive concept is not limited thereto. The number of nanosheet stacks NSS on one fin-type active region F 9  is not particularly limited. For example, one nanosheet stack NSS may be formed on one fin-type active region F 9 . Still further, although  FIGS.  10 B and  10 C  show that each of the nanosheet stacks NSS includes three nanosheets, embodiments are not limited thereto. For example, each of the nanosheet stacks NSS may include at least two nanosheets (e.g., two, four or more), and the number of nanosheets included in each nanosheet stack NSS is not particularly limited. 
     Each of the first, second, and third nanosheets Ni, N 2 , and N 3  may have a channel region. In example embodiments, each of the first, second, and third nanosheets N 1 , N 2 , and N 3  may include, for example, a Si layer, a SiGe layer, or a combination thereof. 
     A plurality of recess regions R 9  may be formed in an upper portion of the fin-type active region F 9 , and a plurality of source/drain regions  930  may be formed in the recess regions R 9 . The source/drain regions  930  may include, for example, an epitaxially grown semiconductor layer. The source/drain regions  930  may be substantially the same as or similar to the source/drain regions SD described above with reference to  FIGS.  2 A and  2 B . 
     The gate lines  960  may be on the fin-type active regions F 9  to cover the nanosheet stacks NSS and surround each of the first, second, and third nanosheets N 1 , N 2 , and N 3 . Each of the gate lines  960  may include a main gate portion  960 M, which extends (e.g., extends longitudinally) in the second horizontal direction (the Y direction) to cover the top surface of a nanosheet stack NSS, and a plurality of sub gate portions  960 S, which are integrally connected to the main gate portion  960 M and respectively between the third nanosheet N 3  and the second nanosheet N 2 , between the second nanosheet N 2  and the first nanosheet N 1 , and between the first nanosheet N 1  and a fin-type active region F 9 . The first, second, and third nanosheets N 1 , N 2 , and N 3  may have a gate-all-around (GAA) structure surrounded by a gate line  960 . The gate line  960  may include, for example, a metal, a metal nitride, a metal carbide, or a combination thereof. The metal may be selected from, for example, Ti, W, Ru, Nb, Mo, Hf, Ni, Co, Pt, Yb, Tb, Dy, Er, and Pd. The metal nitride may be selected from, for example, TiN and TaN. The metal carbide may include, for example, TiAlC. A gate insulating film  952  may be between the nanosheet stack NSS and the gate line  960 . The gate insulating film  952  may be substantially the same as or similar to the gate insulating film  132  described with reference to  FIGS.  2 A and  2 B . 
     A metal silicide film  982  may be formed on the top surface of each of the source/drain regions  930 . The metal silicide film  982  may be substantially the same as or similar to the metal silicide film  152  described with reference to  FIGS.  2 A and  2 B . The metal silicide film  982  may be omitted. 
     Both sidewalls of each of the gate lines  960  may be covered with a plurality of outer insulating spacers  918 . The outer insulating spacers  918  may be on a plurality of nanosheet stacks NSS to cover both sidewalls of the main gate portion  960 M. The outer insulating spacers  918  and the source/drain regions  930  may be covered with an insulating liner  942 . The outer insulating spacers  918  and the insulating liner  942  may include, for example, SiN, SiCN, SiBN, SiON, SiOCN, SiBCN, SiOC, SiO 2 , or a combination thereof. The insulating liner  942  may be omitted. 
     A plurality of inner insulating spacers  928  are between the third nanosheet N 3  and the second nanosheet N 2 , between the second nanosheet N 2  and the first nanosheet N 1 , and between the first nanosheet N 1  and the fin-type active region F 9 . Each of both sidewalls of each of the sub gate portions  960 S may be covered with an inner insulating spacer  928  with the gate insulating film  952  between the sidewall of each sub gate portion  960 S and the inner insulating spacer  928 . A plurality of inner insulating spacers  928  may be between the sub gate portions  960 S and a source/drain region  930 . In example embodiments, the outer insulating spacers  918  and the inner insulating spacers  928  may include the same insulating material as each other. In example embodiments, the outer insulating spacers  918  and the inner insulating spacers  928  may include different insulating materials from each other. The inner insulating spacer  928  may include, for example, SiN, SiCN, SiBN, SiON, SiOCN, SiBCN, SiOC, SiO 2 , or a combination thereof. The inner insulating spacer  928  may further include an air gap. 
     The insulating liner  942  may be covered with an intergate insulating film  944 . The intergate insulating film  944  may include, for example, a silicon oxide film. A plurality of source/drain contact patterns CAP 9  may be respectively in a plurality of contact holes  980 , which pass through the intergate insulating film  944  and the insulating liner  942 . Each of the source/drain contact patterns CAP 9  may be connected to the source/drain region  930  through the metal silicide film  982 . Each of the source/drain contact patterns CAP 9  may include a conductive barrier film  954  and a metal plug  956 . Each of the source/drain contact patterns CAP 9  may include a first segment S 91  and a second segment S 92 , which have different heights in the vertical direction (the Z direction) and are integrally connected to each other. 
     In each of the source/drain contact patterns CAP 9 , the conductive barrier film  954  and the metal plug  956  may extend across the first segment S 91  and the second segment S 92  to be included in the first segment S 91  and the second segment S 92 . 
     In the first segment S 91  of each of the source/drain contact patterns CAP 9 , the top surface of the conductive barrier film  954  may be coplanar with the top surface of the metal plug  956  at a vertical level LV 91 . In the second segment S 92  of each of the source/drain contact patterns CAP 9 , a vertical level LV 92  of the topmost surface of the conductive barrier film  954  is lower than a vertical level LV 93  of the topmost surface of the metal plug  956 . A height difference between the vertical level LV 93  of the topmost surface of the metal plug  956  and the vertical level LV 92  of the topmost surface of the conductive barrier film  954  in the second segment S 92  may be about 1 nm to about 5 nm, for example, about 2 nm to about 3 nm. 
     In the second segment S 92  of each of the source/drain contact patterns CAP 9 , the metal plug  956  may include a protruding top portion  956 P at a level higher than the vertical level LV 92  of the topmost surface of the conductive barrier film  954 . In the second segment S 92  of each of the source/drain contact patterns CAP 9 , a sidewall of the protruding top portion  956 P of the metal plug  956  may not be covered with the conductive barrier film  954 . 
     Similar to the protruding top portion  156 P illustrated in  FIGS.  3 A and  3 B , the protruding top portion  956 P may have a flat top surface (e.g., a substantially planar top surface). However, embodiments are not limited thereto. For example, the metal plug  956  may include, instead of the protruding top portion  956 P, a protruding top portion having a shape the same as or similar to one of the protruding top portions  356 P,  456 P, and  556 P illustrated in  FIGS.  5 A through  7 B . 
     The conductive barrier film  954  and the metal plug  956 , which form each of the source/drain contact patterns CAP 9 , may be substantially the same as or similar to, respectively, the conductive barrier film  154  and the metal plug  156 , which have been described with reference to  FIGS.  2 A through  3 B . Each of the gate lines  960  may be covered with an insulating capping line  940 . The insulating capping line  940  may have a different thickness at a different position. For example, the insulating capping line  940  may have a variable thickness in the first horizontal direction (the X direction). The insulating capping line  940  may be substantially the same as or similar to the insulating capping line  140  described with reference to  FIGS.  2 A and  2 B . 
     A buried insulating film  970  may cover the top surface of the second segment S 92  of each of the source/drain contact patterns CAP 9  and the top surface of the insulating capping line  940 . The buried insulating film  970  may be in contact with the top surface of the second segment S 92  and the top surface of the insulating capping line  940 . 
     The buried insulating film  970  may include a main buried portion  970 M and a buried protrusion  970 P protruding from the main buried portion  970 M toward the substrate  902 . The main buried portion  970 M may be in contact with the top surface of the metal plug  956  included in each of a plurality of second segments S 92 , a portion of the insulating liner  942 , a portion of the intergate insulating film  944 , and a plurality of insulating capping lines  940 . The buried protrusion  970 P may be on the second segment S 92  of each of the source/drain contact patterns CAP 9  to be in contact with the top surface of the conductive barrier film  954 . The buried protrusion  970 P may also be in contact with the sidewall of the protruding top portion  956 P of the metal plug  956 . The buried protrusion  970 P may fill a space, which is defined by the top surface of the conductive barrier film  954  of the second segment S 92 , the sidewall of the protruding top portion  956 P of the metal plug  956 , and a sidewall of the intergate insulating film  944 . 
     The buried insulating film  970  may have a planarized top surface. The buried insulating film  970  may include a portion filling a space above the second segment S 92  of each of the source/drain contact patterns CAP 9  among the gate lines  960 . The top surface of the buried insulating film  970  may be coplanar with the respective topmost surfaces of the conductive barrier film  954  and the metal plug  956 , which are included in the first segment S 91  of each of the source/drain contact patterns CAP 9 , and may be substantially at the vertical level LV 91 . The detailed configuration of the buried insulating film  970  may be the same as or similar to that of the buried insulating film  170  described above with reference to  FIGS.  2 A through  3 B . The integrated circuit device  900  described with reference to  FIGS.  10 A through  10 C  includes the metal plug  956 , which includes the protruding top portion  956 P in the second segment S 92  of each of the source/drain contact patterns CAP 9 . The sidewall of the protruding top portion  956 P may be covered with the buried protrusion  970 P of the buried insulating film  970 . Accordingly, a separation distance from the conductive barrier film  954  and the metal plug  956 , which form the second segment S 92 , to another conductive region adjacent to the second segment S 92  may be secured at least by the buried protrusion  970 P. Therefore, an insulation margin between the second segment S 92  of each of the source/drain contact pattern CAP 9  and an adjacent conductive region may be secured, thereby reducing or preventing an undesirable short-circuit between the second segment S 92  and the adjacent conductive region and increasing the reliability of the integrated circuit device  900 . 
     Methods of manufacturing integrated circuit devices according to some embodiments of the present inventive concept will be described with specific examples below. 
       FIGS.  11 A through  22 B  are cross-sectional views illustrating a method of manufacturing an integrated circuit device, according to some embodiments of the present inventive concept.  FIGS.  11 A,  12 A,  13 A,  14 A,  15 A,  16 A,  17 A,  18 A,  19 A,  20 A,  21 A, and  22 A  show portions respectively corresponding to the cross-sections respectively taken along the lines X 1 -X 1 ′ and X 2 -X 2 ′ in  FIG.  1   , and  FIGS.  11 B,  12 B,  13 B,  14 B,  15 B,  16 B,  17 B,  18 B,  19 B,  20 B,  21 B, and  22 B  show a portion corresponding to the cross-section taken along the line Y 1 -Y 1 ′ in  FIG.  1   . An example of a method of manufacturing the integrated circuit device  100  illustrated in  FIGS.  1  through  3 B  will be described with reference to  FIGS.  11 A through  22 B  below. 
     Referring to  FIGS.  11 A and  11 B , a plurality of fin-type active regions FA, which protrude in the vertical direction (the Z direction) from the main surface  110 M of the substrate  110  and extend in the first horizontal direction (the X direction) to be parallel to each other, and an isolation film  112 , which covers both sidewalls of a lower portion of each of the fin-type active regions FA, may be formed by partially etching the substrate  110  in the first device region RX 1  and the second device region RX 2 . A deep trench DT, which defines the first device region RX 1  and the second device region RX 2 , may be formed by etching a portion of the isolation film  112  and a portion of the substrate  110  and may be filled with an isolation insulating film  114 . Accordingly, the deep trench DT in the device isolation region DTA may be filled with the isolation insulating film  114 . In the first device region RX 1  and the second device region RX 2 , the fin-type active regions FA may protrude upward from the top surface of the isolation film  112 . 
     Referring to  FIGS.  12 A and  12 B , a plurality of dummy gate structures DGS extending to cross the fin-type active regions FA are formed on the isolation film  112  and the isolation insulating film  114 . Each of the dummy gate structures DGS may include a dummy gate insulating film D 12 , a dummy gate line D 14 , and a dummy insulating capping layer D 16 , which are sequentially stacked on the fin-type active regions FA. The dummy gate insulating film D 12  may include, for example, silicon oxide. The dummy gate line D 14  may include, for example, polysilicon. The dummy insulating capping layer D 16  may include, for example, silicon nitride. 
     An insulating spacer  120  may be formed on each of both sidewalls of each of the dummy gate structures DGS, and a plurality of recess regions RR may be formed in an upper portion of each of a plurality of fin-type active regions FA by partially etching the fin-type active regions FA exposed at both sides of each dummy gate structure DGS. Thereafter, a plurality of source/drain regions SD filling the recess regions RR may be formed. 
     The isolation film  112 , the isolation insulating film  114 , the source/drain regions SD, and the intergate insulating film  128  covering the source/drain regions SD may be formed among the dummy gate structures DGS. In example embodiments, before the intergate insulating film  128  is formed, an insulating liner (not shown) covering the source/drain regions SD may also be formed. The insulating liner may include, for example, SiN, SiCN, SiBN, SiON, SiOCN, SiBCN, SiOC, SiO 2 , or a combination thereof. 
     Referring to  FIGS.  13 A and  13 B , the dummy gate line D 14  is exposed by removing the dummy insulating capping layer D 16  and insulating films around the dummy insulating capping layer D 16  from the resultant structure of  FIGS.  12 A and  12 B  by using, for example, a chemical mechanical polishing (CMP) process. At this time, the heights of the intergate insulating film  128  and the insulating spacer  120  may be lowered. 
     Referring to  FIGS.  14 A and  14 B , a plurality of gate spaces GA are provided by removing a plurality of dummy gate lines D 14  and a plurality of dummy gate insulating films D 12  from the resultant structure of  FIGS.  13 A and  13 B . The insulating spacer  120 , the fin-type active regions FA, the isolation film  112 , and the isolation insulating film  114  may be exposed by the gate spaces GA. 
     Referring to  FIGS.  15 A and  15 B , a gate insulating film  132 , a gate line GL, and an insulating capping line  140  are formed in the gate spaces GA of the resultant structure of  FIGS.  14 A and  14 B . 
     To form the gate insulating film  132 , the gate line GL, and the insulating capping line  140 , a plurality of gate insulating films  132  and a plurality of gate lines GL may be formed to fill the gate spaces GA and then etched back to be lowered so as to fill only lower portions of the gate spaces GA. During the etch-back of the gate insulating films  132  and the gate lines GL, an upper portion of the insulating spacer  120  defining the gate spaces GA may also be removed such that the height of the insulating spacer  120  may be lowered. Thereafter, the insulating capping line  140  may be formed to cover the top surface of each of the gate lines GL, the gate insulating films  132 , and the insulating spacer  120  in the gate spaces GA and to fill the upper portions of the gate spaces GA. 
     In example embodiments, before the gate insulating films  132  are formed, an interface film (not shown) may be formed to cover the surface of each of the fin-type active regions FA exposed by the gate spaces GA. For example, to form the interface film, the fin-type active regions FA exposed in the gate spaces GA may be partially oxidized. 
     Referring to  FIGS.  16 A and  16 B , a plurality of source/drain contact holes CAH are formed to expose the source/drain regions SD through the intergate insulating film  128 , and a contact insulating spacer  150  is formed to cover the inner sidewalls of each of the source/drain contact holes CAH. To form the contact insulating spacer  150 , an insulating spacer film may be formed to conformally cover the inner wall of each of the source/drain contact holes CAH and then anisotropically etched to expose a source/drain region SD through each source/drain contact hole CAH. Consequently, a plurality of contact insulating spacers  150  each including a portion of the insulating spacer film remaining on the sidewall of the source/drain contact hole CAH may be obtained. 
     A plurality of metal silicide films  152 , which respectively cover the source/drain regions SD in the lower portions of the source/drain contact holes CAH, and a plurality of preliminary source/drain contacts RCA, which respectively fill the source/drain contact holes CAH, are formed. The preliminary source/drain contacts RCA may include the conductive barrier film  154  and the metal plug  156 . In the present specification, the conductive barrier film  154  included in the preliminary source/drain contacts RCA may be referred to as a “preliminary conductive barrier film”, and the metal plug  156  included in the preliminary source/drain contacts RCA may be referred to as a “preliminary metal plug”. 
     In example embodiments, the metal silicide films  152 , the conductive barrier film  154 , and the metal plug  156  may be formed by performing the processes described below. Firstly, a metal liner conformally covering the source/drain regions SD may be formed in the source/drain contact holes CAH. The metal liner may include, for example, Ti, W, Ru, Nb, Mo, Hf, Ni, Co, Pt, Yb, Tb, Dy, Er, Pd, or a combination thereof. Thereafter, the conductive barrier film  154  may be formed to cover an exposed surface of the metal liner and the inner walls of the source/drain contact holes CAH. The metal liner and the conductive barrier film  154  may be formed using, for example, physical vapor deposition (PVD), CVD, or atomic layer deposition (ALD). Thereafter, a heat treatment may be performed on a resultant structure including the metal liner and the conductive barrier film  154  to induce a reaction between a semiconductor material of the source/drain regions SD and a metal of the metal liner, thereby forming the metal silicide films  152  covering the source/drain regions SD. In example embodiments, after the metal silicide films  152  are formed, a portion of the metal liner may remain between each of the metal silicide films  152  and the conductive barrier film  154 . In example embodiments, the entire metal liner may be used to form the metal silicide films  152  and thus the metal liner may not remain between each of the metal silicide films  152  and the conductive barrier film  154 . 
     Thereafter, a metal film may be formed on a resultant structure including the metal silicide films  152  and the conductive barrier film  154  to be thick enough to fill the inside of each of the source/drain contact holes CAH. The metal film may be formed using, for example, CVD, PVD, or electroplating. Thereafter, the metal plug  156  including the metal film remaining on the conductive barrier film  154  in each of the source/drain contact holes CAH may be formed by removing the conductive barrier film  154  and an unnecessary portion of the metal film using, for example, CMP to expose the top surface of the intergate insulating film  128 . 
     Referring to  FIGS.  17 A and  17 B , the height of the top surface of the conductive barrier film  154  is lowered by performing an etch-back process for selectively removing a portion (e.g., an upper portion) of the conductive barrier film  154  in the resultant structure of  FIGS.  16 A and  16 B . As a result, an upper recess UR exposing the top surface of the conductive barrier film  154  may be formed between the metal plug  156  and a contact insulating spacer  150  in each of the source/drain contact holes CAH. An outer sidewall of the metal plug  156  and an inner sidewall of the contact insulating spacer  150  may be exposed by the upper recess UR. 
     In example embodiments, a vertical height URH of the upper recess UR exposing the top surface of the conductive barrier film  154  may be about 1 nm to about 5 nm, for example, about 2 nm to about 3 nm. 
     Referring to  FIGS.  18 A and  18 B , an etch stop film  160  is formed to cover the top surface of the resultant structure of  FIGS.  17 A through  17 B , and a plurality of mask patterns MP may be formed on the etch stop film  160  to partially cover the preliminary source/drain contacts RCA. The mask patterns MP may be positioned to correspond to the source/drain via contacts CAV in  FIG.  1   . In some embodiments, each of the mask pattern MP may overlap a first portion of the upper recess UR and may not overlap a second portion of the upper recess UR as illustrated in  FIGS.  18 A and  18 B . 
     The etch stop film  160  may include a different material than the mask patterns MP. In example embodiments, the etch stop film  160  may include, for example, SiOC, SiN, or a combination thereof, and the mask patterns MP may include, for example, a silicon oxide film, a spin-on-hardmask (SOH) film, a photoresist film, or a combination thereof, but embodiments are not limited thereto. 
     Referring to  FIGS.  19 A and  19 B , the etch stop film  160  is etched using the mask patterns MP as etch masks, and the preliminary source/drain contacts RCA that are exposed are etched in a certain etching atmosphere to be lowered. As a result, a plurality of source/drain contact patterns CAP having different heights at different positions may be formed. Each of the source/drain contact patterns CAP may include a first segment S 1  and a second segment S 2 , which have different heights in the vertical direction (the Z direction) and are integrally connected to each other. The first segment S 1  may include a first portion of the metal plug  156 , and a second segment S 2  may include a second portion of the metal plug  156 . Each of the first and second portions of the metal plug  156  may be a portion of a metal film that is a monolithic or unitary film and is formed by a single process, and the first and second portions of the metal plug  156  may be connected to each other without an interface or boundary. The first segment S 1  may include a first portion of the conductive barrier film  154 , and a second segment S 2  may include a second portion of the conductive barrier film  154 . Each of the first and second portions of the conductive barrier film  154  may be a portion of a barrier film that is a monolithic or unitary film is formed by a single process, and the first and second portions of the conductive barrier film  154  may be connected to each other without an interface or boundary. 
     The certain etching atmosphere may be provided to etch a metal containing film forming the preliminary source/drain contacts RCA. In the certain etching atmosphere, the etching amount of the metal containing film forming the preliminary source/drain contacts RCA may be greater than the etching amount of an insulating film forming a plurality of insulating capping lines  140 , and the etching amount of the insulating film forming the insulating capping lines  140  may be greater than 0. While each of the metal plug  156  and the contact insulating spacer  150  is being lowered by etching the exposed portions of the preliminary source/drain contacts RCA using the mask patterns MP as etch masks, the profile of the top surface of a preliminary source/drain contact RCA including the upper recess UR illustrated in  FIGS.  17 A and  17 B  may be transferred downwards. As a result, after the source/drain contact patterns CAP are formed, a lower recess LR exposing the top surface of the conductive barrier film  154  may be formed on a top surface of the second segment S 2  of each of the source/drain contact patterns CAP, which is between the metal plug  156  and the contact insulating spacer  150 . The outer sidewall of the metal plug  156  of each of the source/drain contact patterns CAP and the inner sidewall of the contact insulating spacer  150  may be exposed by the lower recess LR. 
     In example embodiments, a vertical height LRH of the lower recess LR exposing the top surface of the conductive barrier film  154  may be about 1 nm to about 5 nm, for example, about 2 nm to about 3 nm. 
     The heights of portions of the insulating capping lines  140 , which are exposed to the certain etching atmosphere while the exposed portions of the preliminary source/drain contacts RCA are being etched using the mask patterns MP as etch masks, may be lowered. 
     While the source/drain contact patterns CAP including the first segment S 1  and the second segment S 2  are being formed, the height of each of the mask patterns MP, a plurality of insulating spacers  120 , and the intergate insulating film  128  may be lowered in the certain etching atmosphere. 
     Referring to  FIGS.  20 A and  20 B , an insulating film is formed on the resultant structure of  FIGS.  19 A and  19 B  to have a thickness enough to fill spaces among the mask patterns MP, and planarization is performed on a resultant structure including the insulating film to form the buried insulating film  170  including the planarized insulating film. While the planarization is being performed until the buried insulating film  170  is obtained, the mask patterns MP, the etch stop film  160 , an upper portion of each of the source/drain contact patterns CAP are removed such that the respective top surfaces of the conductive barrier film  154  and the metal plug  156 , which form the first segment S 1  of each of the source/drain contact patterns CAP, may be coplanar with each other and may be substantially at the vertical level LV 1 . 
     The second segment S 2  of each of the source/drain contact patterns CAP and the insulating capping lines  140  may be covered with the buried insulating film  170 . The buried insulating film  170  may be formed to fill a space above the second segment S 2  of each of the source/drain contact patterns CAP among the gate lines GL. The buried insulating film  170  may include the buried protrusion  170 P, which fills the lower recess LR (see  FIGS.  19 A and  19 B ) on the top surface of the second segment S 2 . 
     The buried insulating film  170  may have a planarized top surface (e.g., a flat or substantially planar top surface). The top surface of the buried insulating film  170  may extend substantially at the vertical level LV 1  on the same plane as the respective top surfaces of the conductive barrier film  154  and the metal plug  156 , which form the first segment S 1 . 
     Referring to  FIGS.  21 A and  21 B , the insulating structure  180  is formed on the resultant structure of  FIGS.  20 A and  20 B . The insulating structure  180  may include the etch stop film  182  and the interlayer insulating film  184 , which are sequentially formed on the buried insulating film  170  and the source/drain contact patterns CAP. 
     Referring to  FIGS.  22 A and  22 B , a plurality of source/drain via contacts CAV connected to the respective first segments S 1  of the source/drain contact patterns CAP and a plurality of gate contacts CB connected to a plurality of gate lines GL, respectively, are formed. 
     In example embodiments, the source/drain via contacts CAV and the gate contacts CB may be simultaneously formed. In example embodiments, the source/drain via contacts CAV and the gate contacts CB may be sequentially formed using separate processes. In this case, the gate contacts CB may be formed after the source/drain via contacts CAV are formed, or the source/drain via contacts CAV may be formed after the gate contacts CB are formed. 
     Each of the source/drain via contacts CAV may pass through the insulating structure  180  and be in contact with the top surface of the first segment S 1  of one of the source/drain contact patterns CAP. Each of the gate contacts CB may pass through the interlayer insulating film  184 , the etch stop film  182 , the buried insulating film  170 , and one of the insulating capping lines  140  and be in contact with the top surface of one of the gate lines GL. 
     Each of some gate contacts CB may be in contact with the gate line GL in a location adjacent to the second segment S 2  of the source/drain contact pattern CAP. In this case, as shown in  FIGS.  22 A , the buried protrusion  170 P of the buried insulating film  170  may be between the second segment S 2  of the source/drain contact pattern CAP and the gate line GL adjacent to the second segment S 2  in the first horizontal direction (the X direction). Accordingly, a separation distance from the conductive barrier film  154  and the metal plug  156 , which form the second segment S 2 , to the gate line GL may be secured at least by the buried protrusion  170 P. Therefore, even when the gate contact CB is adjacent to the second segment S 2  of the source/drain contact pattern CAP, an insulation margin between the gate contact CB and the source/drain contact pattern CAP may be secured, thereby reducing or preventing an undesirable short-circuit between the gate contact CB and the source/drain contact pattern CAP. 
       FIGS.  23 A through  23 D  are cross-sectional views illustrating a method of manufacturing an integrated circuit device, according to some embodiments of the present inventive concept.  FIGS.  23 A through  23 D  show cross-sectional views of portions respectively corresponding to the cross-sections, respectively taken along the lines X 1 -X 1 ′ and X 2 -X 2 ′ in  FIG.  1   , in the sequential stages. Another example of a method of manufacturing the integrated circuit device  100  illustrated in  FIGS.  1  through  3 B  will be described with reference to  FIGS.  23 A through  23 D  below. 
     Referring to  FIG.  23 A , the etch stop film  160  and a plurality of mask patterns MP are formed on the resultant structure, which is obtained by performing the method described with reference to  FIGS.  11 A through  16 B  to form a plurality of preliminary source/drain contacts RCA, using the method described with reference to  FIGS.  18 A and  18 B . 
     Referring to  FIG.  23 B , the etch stop film  160  is etched using the mask patterns MP as etch masks in the resultant structure of  FIG.  23 A , thereby exposing some of the preliminary source/drain contacts RCA. 
     Referring to  FIG.  23 C , an etch-back process is performed on the resultant structure of  FIG.  23 B  using the mask patterns MP as etch masks so that a portion of the conductive barrier film  154  in each exposed one among the preliminary source/drain contacts RCA is selectively removed by the method described with reference to  FIGS.  17 A and  17 B . As a result, the height of the top surface of the conductive barrier film  154  is lowered and the upper recess UR is formed. 
     Referring to  FIG.  23 D , a plurality of source/drain contact patterns CAP each including a first segment S 1  and a second segment S 2 , which are integrally connected to each other, are formed by a method similar to that described with reference to  FIGS.  19 A and  19 B  by etching the preliminary source/drain contacts RCA in the resultant structure of  FIG.  23 C  using the mask patterns MP as etch masks. The lower recess LR exposing the top surface of the conductive barrier film  154  may be formed on the top surface of the second segment S 2  of each of the source/drain contact patterns CAP, which is between the metal plug  156  and the contact insulating spacer  150 . 
     Thereafter, the integrated circuit device  100  illustrated in  FIGS.  1  through  3 B  may be manufactured by performing the processes described with reference to  FIGS.  20 A through  22 B . 
       FIGS.  24 A and  24 B  are cross-sectional views illustrating a method of manufacturing an integrated circuit device, according to some embodiments of the present inventive concept.  FIGS.  24 A and  24 B  show cross-sectional views of portions respectively corresponding to the cross-sections, respectively taken along the lines X 1 -X 1 ′ and X 2 -X 2 ′ in  FIG.  1   , in the sequential stages. Still another example of a method of manufacturing the integrated circuit device  100  illustrated in  FIGS.  1  through  3 B  will be described with reference to  FIGS.  24 A and  24 B  below. 
     Referring to  FIG.  24 A , after the etch stop film  160  and the mask patterns MP are formed on a resultant structure including the preliminary source/drain contacts RCA formed by the method described with reference to  FIGS.  23 A and  23 B , and the preliminary source/drain contacts RCA are etched, using the mask patterns MP as etch mask, by a method similar to that described with reference to  FIG.  23 D  so that the height of a portion corresponding to the second segment S 2  of each of the source/drain contact patterns CAP illustrated in  FIGS.  2 A and  2 B  is lowered. 
     While the heights of some of the preliminary source/drain contacts RCA are being lowered by etching exposed portions of the preliminary source/drain contacts RCA using the mask patterns MP as etch masks, the profile of the top surface of each of the preliminary source/drain contacts RCA in  FIG.  23 B  may be transferred downwards. As a result, in a portion in which the height of each of the preliminary source/drain contacts RCA is lowered, the top surface of the conductive barrier film  154  may be substantially at the same level as the top surface of the metal plug  156 . 
     Referring to  FIG.  24 B , an etch-back process is performed on the resultant structure of  FIG.  24 A  using the mask patterns MP as etch masks so that a portion of the conductive barrier film  154  in each exposed one among the preliminary source/drain contacts RCA is selectively removed by a method similar to the method described with reference to  FIGS.  17 A and  17 B , thereby lowering the height of the top surface of the conductive barrier film  154  and forming a lower recess LR. As a result, a plurality of source/drain contact patterns CAP each including a first segment S 1  and a second segment S 2 , which are integrally connected to each other, may be formed. 
     In some embodiments, instead of performing the process described with reference to  FIG.  24 B , the resultant structure of  FIG.  24 B  may be obtained from the resultant structure of  FIG.  23 B , using one-step etching of the preliminary source/drain contacts RCA, by applying an etching atmosphere, in which an etch selectivity of each of the conductive barrier film  154  and the metal plug  156  may be appropriately controlled, while the preliminary source/drain contacts RCA are being etched using the mask patterns MP as etch masks in the process described with reference to  FIG.  24 A . The structure shown in  FIG.  24 B  may be formed by performing a single etch process on the structure shown in  FIG.  23 B  using the mask patterns MP as etch masks. 
     Thereafter, the integrated circuit device  100  illustrated in  FIGS.  1  through  3 B  may be manufactured by performing the processes described with reference to  FIGS.  20 A through  22 B . 
     Although examples of a method of manufacturing the integrated circuit device  100  illustrated in  FIGS.  1  through  3 B  have been described with reference to  FIGS.  11 A through  22 B ,  FIGS.  23 A through  23 D , and  FIGS.  24 A and  24 B , it will be understood by those skilled in the art that the integrated circuit device  200  illustrated in  FIGS.  4 A and  4 B , the integrated circuit device  300  illustrated in  FIGS.  5 A and  5 B , the integrated circuit device  400  illustrated in  FIGS.  6 A and  6 B , the integrated circuit device  500  illustrated in  FIGS.  7 A and  7 B , the integrated circuit device  600  illustrated in  FIGS.  8 A and  8 B , the integrated circuit device  700  illustrated in  FIG.  9   , the integrated circuit device  900  illustrated in  FIGS.  10 A through  10 C , and other integrated circuit devices having various structures modified and changed therefrom may be manufactured by making various modifications and changes to the methods described with reference to  FIGS.  11 A through  22 B ,  FIGS.  23 A through  23 D , and  FIGS.  24 A and  24 B , without departing from the scope of the present inventive concept. 
     In example embodiments, the processes of manufacturing the integrated circuit device  100 , which are described with reference to  FIGS.  11 A through  22 B , may be used to manufacture the integrated circuit device  200  illustrated in  FIGS.  4 A and  4 B . However, after the source/drain via contacts CAV and the gate contacts CB are formed in the stage described with reference to  FIGS.  22 A and  22 B , a process of forming a plurality of conductive lines ML connected to the source/drain via contacts CAV and the gate contacts CB may be further performed. 
     In example embodiments, to manufacture the integrated circuit device  300  illustrated in  FIGS.  5 A and  5 B  and the integrated circuit device  400  illustrated in  FIGS.  6 A and  6 B , the processes of manufacturing the integrated circuit device  100 , which have been described with reference to  FIGS.  11  through  22 B , may be used. However, in the process of forming the upper recess UR, as described with reference to  FIGS.  17 A and  17 B , and/or the process of forming the lower recess LR, as described with reference to  FIGS.  19 A and  19 B , the etch selectivity of the conductive barrier film  154  with respect to the metal plug  156  may be controlled such that, instead of the metal plug  156 , the metal plug  356 , which has the rounded corner  356 C in the outer edge of the protruding top portion  356 P, as describe with reference to  FIGS.  5 A and  5 B , or the metal plug  456 , which has the top surface portion  456 T and the rounded corner  456 C in the protruding top portion  456 P, as describe with reference to  FIGS.  6 A and  6 B , may be formed in the final structure including the lower recess LR. 
     In example embodiments, to manufacture the integrated circuit device  500  illustrated in  FIGS.  7 A and  7 B , the processes of manufacturing the integrated circuit device  100 , which have been described with reference to  FIGS.  11  through  22 B , may be used. However, in the process of forming the metal plug  156 , as described with reference to  FIGS.  16 A and  16 B , the metal plug  156  may be formed to have a seam or a void at least in an inner portion thereof in the process of forming the upper recess UR, as described with reference to  FIGS.  17 A and  17 B , and/or the process of forming the lower recess LR, as described with reference to  FIGS.  19 A and  19 B , the etch selectivity of the conductive barrier film  154  with respect to the metal plug  156  may be controlled such that a portion of the metal plug  156 , which is relatively weak because of the seam or the void in the metal plug  156 , is also etched during an etching process for the formation of the upper recess UR or the lower recess LR, so as to form the metal plug  556 , which has a double-humped protrusion in the protruding top portion  556 P, instead of the metal plug  156 , in the final structure including the lower recess LR. 
       FIGS.  25 A through  31    are cross-sectional views illustrating a method of manufacturing an integrated circuit device, according to some embodiments of the present inventive concept, wherein  FIGS.  25 A,  26 A,  27 A,  28 A,  29 A,  30 A, and  31    show a portion corresponding to the cross-section taken along the line X 9 -X 9 ′ in  FIG.  10 A , and  FIGS.  25 B,  26 B,  27 B,  28 B,  29 B, and  30 B  show a portion corresponding to the cross-section taken along the line Y 9 -Y 9 ′ in  FIG.  10 A . An example of a method of manufacturing the integrated circuit device  900  illustrated in  FIGS.  10 B through  10 C  will be described with reference to  FIGS.  25 A through  31    below. In  FIGS.  1  through  10 C  and  FIGS.  25 A and  31   , like reference numerals and characters denote like elements, and detailed descriptions thereof may be omitted. 
     Referring to  FIGS.  25 A and  25 B , a plurality of sacrificial semiconductor layers  904  and a plurality of nanosheet semiconductor layers NS are alternately stacked on the substrate  902 . The sacrificial semiconductor layers  904  may include a different material than the nanosheet semiconductor layers NS. In example embodiments, the sacrificial semiconductor layers  904  may include, for example, SiGe, and the nanosheet semiconductor layers NS may include, for example, Si. 
     Referring to  FIGS.  26 A and  26 B , a trench T 9  is formed by partially etching the sacrificial semiconductor layers  904 , the nanosheet semiconductor layers NS, and the substrate  902 , and the isolation film  912  is formed in the trench T 9 . As a result, a fin-type active region F 9  defined by the trench T 9  may be formed. A stack structure of the sacrificial semiconductor layers  904  and the nanosheet semiconductor layers NS remains on the top surface FT of the fin-type active region F 9 . 
     Referring to  FIGS.  27 A and  27 B , a plurality of dummy gate structures DGS 9  are formed on the stack structure of the sacrificial semiconductor layers  904  and the nanosheet semiconductor layers NS of the resultant structure of  FIGS.  26 A and  26 B , and a plurality of outer insulating spacers  918  respectively covering both sidewalls of each of the dummy gate structures DGS 9  are formed. Thereafter, the sacrificial semiconductor layers  904  and the nanosheet semiconductor layers NS are partially etched using the dummy gate structures DGS 9  and the outer insulating spacers  918  as etch masks such that the nanosheet semiconductor layers NS are separated into a plurality of nanosheet stacks NSS including the first, second, and third nanosheets N 1 , N 2 , and N 3 . Thereafter, the fin-type active region F 9  exposed among the nanosheet stacks NSS is etched, thereby forming a plurality of recess regions R 9  in the upper portion of the fin-type active region F 9 . 
     Each of the dummy gate structures DGS 9  may extend (e.g., extend longitudinally) in the second horizontal direction (the Y direction). Each of the dummy gate structures DGS 9  may have a structure, in which an insulating layer D 962 , a dummy gate layer D 964 , and a capping layer D 966  are sequentially stacked. In example embodiments, the insulating layer D 962  may include, for example, silicon oxide, the dummy gate layer D 964  may include, for example, polysilicon, and the capping layer D 966  may include, for example, silicon nitride. 
     Referring to  FIGS.  28 A and  28 B , a plurality of indents (e.g., openings) are formed among the first, second, and third nanosheets N 1 , N 2 , and N 3  and the top surface FT by partially removing the sacrificial semiconductor layers  904  exposed around the recess regions R 9  of the resultant structure of  FIGS.  27 A and  27 B , and a plurality of inner insulating spacers  928  filling the indents are formed. 
     Referring to  FIGS.  29 A and  29 B , a plurality of source/drain regions  930  are formed by epitaxially growing a semiconductor material from exposed surfaces of the recess regions R 9  of the resultant structure of  FIGS.  28 A and  28 B , an insulating liner  942  is formed to cover a resultant structure including the source/drain regions  930 , an intergate insulating film  944  is formed on the insulating liner  942 , and the top surface of the capping layer D 966  is exposed by planarizing the top surface of each of the insulating liner  942  and the intergate insulating film  944 . Thereafter, a gate space GS is provided by removing the dummy gate structures DGS 9 , and the sacrificial semiconductor layers  904  are removed through the gate space GS such that the gate space GS extends to spaces among the first, second, and third nanosheets N 1 , N 2 , and N 3  and the top surface FT. 
     Referring to  FIGS.  30 A and  30 B , a gate insulating film  952  is formed to cover an exposed surface of each of the first, second, and third nanosheets N 1 , N 2 , and N 3  and the fin-type active region F 9 , a plurality of gate lines  960  are formed on the gate insulating film  952  to fill a plurality of gate spaces GS, and an upper portion of each of the gate lines  960  and an upper portion of each of the gate insulating film  952  and the outer insulating spacers  918 , which are around the gate lines  960 , are removed to empty the upper portion of each of the gate spaces GS. Thereafter, the upper portion of each of the gate spaces GS is filled with an insulating capping line  940 . Because planarization is performed during the formation of the gate lines  960  and the insulating capping line  940 , the height of each of the insulating liner  942  and the intergate insulating film  944  may be lowered. 
     Referring to  FIG.  31   , a plurality of contact holes  980  exposing the source/drain regions  930  are formed by partially etching the intergate insulating film  944  and the insulating liner  942 , and a metal silicide film  982  and a preliminary source/drain contact RCA 9  are formed in each of the contact holes  980 . 
     In example embodiments, the method of forming the metal silicide film  152  and the preliminary source/drain contact RCA, which has been described with reference to  FIGS.  16 A and  16 B , may be used to form the metal silicide film  982  and the preliminary source/drain contact RCA 9 . 
     Thereafter, processes similar to those described with reference to  FIGS.  17 A through  19 B  may be performed on the resultant structure of  FIG.  31   , thereby forming a plurality of source/drain contact patterns CAPS (see  FIG.  10 B ) from a plurality of source/drain contacts RCA 9 . At this time, the height of a portion of the insulating capping line  940  is lowered so that the insulating capping line  940  may have a variable thickness in the first horizontal direction (the X direction). Thereafter, the integrated circuit device  900  illustrated in  FIGS.  10 A through  10 C  may be manufactured by forming the buried insulating film  970  using the method of forming the buried insulating film  170 , which has been described with reference to  FIGS.  20 A and  20 B . 
     In the drawing, two elements that are illustrated to contact each other without an intervening element may directly contact each other. 
     While the present inventive concept has been particularly shown and described with reference to some example embodiments thereof, it will be understood that various changes in form and details may be made therein without departing from the scope of the inventive concept. Thus, to the maximum extent allowed by law, the scope of the inventive concept is to be determined by the broadest permissible interpretation of following claims and their equivalents and shall not be restricted or limited by the foregoing detailed description.