Integrated circuit device and method of manufacturing the same

An integrated circuit device includes a fin type active area protruding from a substrate and having an upper surface at a first level; a nanosheet extending in parallel to the upper surface of the fin type active area and comprising a channel area, the nanosheet being located at a second level spaced apart from the upper surface of the fin type active area; a gate disposed on the fin type active area and surrounding at least a part of the nanosheet, the gate extending in a direction crossing the fin type active area; a gate dielectric layer disposed between the nanosheet and the gate; a source and drain region formed on the fin type active area and connected to one end of the nanosheet; a first insulating spacer on the nanosheet, the first insulating spacer covering sidewalls of the gate; and a second insulating spacer disposed between the gate and the source and drain region in a space between the upper surface of the fin type active area and the nanosheet, the second insulating spacer having a multilayer structure.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 10-2015-0144321, filed on Oct. 15, 2015, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

The 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 metal-oxide-semiconductor field effect transistor (MOSFET) and a method of manufacturing the same.

As the integration degree of semiconductor devices becomes greater, the size of semiconductor devices has been reduced to an extreme state, and scaling thereof has approached the limit. Accordingly, to reduce an effective switching capacitance (Ceff) in semiconductor devices and enhance the performance thereof, new methods may be needed involving structural changes semiconductor devices.

SUMMARY

The inventive concept provides an integrated circuit device having a structure capable of reducing an effective switching capacitance (Ceff) of the integrated semiconductor device and enhancing performance thereof.

The inventive concept also provides a method of manufacturing an integrated circuit device having a structure capable of reducing an effective switching capacitance (Ceff) of the integrated semiconductor device and enhancing performance thereof.

According to an aspect of the inventive concept, there is provided an integrated circuit device including a fin type active area protruding from a substrate and having an upper surface at a first level; a nanosheet extending in parallel to the upper surface of the fin type active area and including a channel area, the nanosheet being located at a second level spaced apart from the upper surface of the fin type active area; a gate disposed on the fin type active area and surrounding at least a part of the nanosheet, the gate extending in a direction crossing the fin type active area; a gate dielectric layer disposed between the nanosheet and the gate; a source and drain region formed on the fin type active area and connected to one end of the nanosheet; a first insulating spacer on the nanosheet, the first insulating spacer covering sidewalls of the gate; and a second insulating spacer disposed between the gate and the source and drain region in a space between the upper surface of the fin type active area and the nanosheet, the second insulating spacer having a multilayer structure.

The gate may include a main gate portion covering an upper surface of the nanosheet and a sub-gate portion connected to the main gate portion and formed in a space between the fin type active area and the nanosheet. The first insulating spacer may cover sidewalls of the main gate portion. The second insulating spacer may cover sidewalls of the sub-gate portion.

The nanosheet may be formed in an overlap region covered by the gate in a space between the fin type active area and the gate and has a planar area greater than a planar area of the overlap region.

The first insulating spacer and the second insulating spacer may include different materials.

The second insulating spacer may include an air space.

The second insulating spacer may have at least a triple layer structure.

The triple layer structure may include an air space.

The second insulating spacer may include: a first liner having a surface facing the gate and the nanowire and including a first insulating material that does not include oxygen; a second liner spaced apart from the gate and the nanowire and including a second insulating material different from the first insulating material, wherein the first liner is between the second liner and the gate and between the second liner and the nanowire; and an air space having at least a part limited by the second liner.

The second insulating spacer may further include a partial burial layer limiting an air space defined by the second liner.

The second insulating spacer may include: a first liner having a surface facing the gate and the nanowire and including a first insulating material that does not include oxygen; a second liner spaced apart from the gate and the nanowire and including a second insulating material different from the first insulating material, wherein the first liner is between the second liner and the gate and between the second liner and the nanowire; and a burial layer filling at least a part of a space defined by the second liner and including a third insulating material different from the second insulating material.

The second insulating spacer may include: a first liner including one of SiN, SiCN, and SiBN; and a second liner spaced apart from the gate and the nanowire and including one of SiON, SiOCN, and SiBCN, wherein the first liner is between the second liner and the gate and between the second liner and the nanowire.

The second insulating spacer may include: a first liner including a first insulating material that does not include oxygen; and a second liner having a composition different from a composition of the first insulating material and having an oxygen content ranging from 0 to about 50 atom %.

The second insulating spacer may include at least one of an air space, SiN, SiCN, SiBN, SiON, SiOCN, SiBCN, SiOC, and SiO2.

The first insulating spacer may include SiN. The second insulating spacer may include an insulating layer contacting the source and drain region and including SiON.

According to another aspect of the inventive concept, there is provided an integrated circuit device including a fin type active area protruding from a substrate and extending in a first direction; at least one nanosheet stack structure facing and spaced apart from an upper surface of the fin type active area, the at least one nanosheet stack structure including a plurality of nanosheets each having a channel area; at least one gate disposed on the fin type active area and covering the at least one nanosheet stack structure, the at least one gate extending in a direction crossing the first direction; at least one gate dielectric layer disposed between the at least one nanosheet stack structure and the at least one gate; source and drain regions connected to the plurality of nanosheets; and insulating spacers each having a multilayer structure and contacting the source and drain regions in spaces between the plurality of nanosheets.

The at least one gate may include a main gate portion on the plurality of nanosheets and a sub-gate portion filling the spaces between the plurality of nanosheets, the main gate portion having a first thickness and the sub-gate portion having a second thickness smaller than the first thickness. The insulating spacers may cover sidewalls of the sub-gate portion.

The insulating spacers may include an air space.

The insulating spacers may include: a first liner spaced apart from the source and drain regions and including a first insulating material that does not include oxygen; and a second liner contacting the source and drain regions, the second liner having a composition different from a composition of the first insulating material and having an oxygen content ranging from 0 to about 50 atom %.

The plurality of nanosheets may be in at least one overlap region covered by the at least one gate, among spaces between the fin type active area and the at least one gate, and has a planar area greater than a planar area of the at least one overlap region.

The at least one nanosheet stack structure may include a plurality of nanosheet stack structures and the at least one gate includes a plurality of gates, wherein the plurality of nanosheet stack structures are arranged in a line along the first direction on the fin type active area and each includes a plurality of the nanosheets. The plurality of gates may extend in parallel to each other on the fin type active area, the plurality of nanosheet stack structures may be arranged between the fin type active area and the plurality of gates.

According to another aspect of the inventive concept, there is provided a method of manufacturing an integrated circuit device, the method including forming a fin type active area protruding from a substrate and having an upper surface at a first level and a nanosheet being located at a second level spaced apart from the upper surface of the fin type active area and extending in parallel to the upper surface of the fin type active area; forming a first insulating spacer on the nanosheet, the first insulating spacer defining a gate space; forming a second insulating spacer in a space between the upper surface of the fin type active are and the nanosheet, the second insulating spacer having a multilayer structure; forming a source and drain region on the fin type active area, the source and drain region being connected to one end of the nanosheet and one end of the second insulating layer; and forming a gate on the fin type active area, wherein the gate extends in a direction crossing the fin type active area, surrounds at least a part of the nanosheet, and faces the source and drain region, and the second insulating spacer is between the gate and the source and drain region.

The forming of the second insulating spacer may include forming a first liner and a second liner sequentially covering a surface of the nanosheet. The first liner and the second liner may include different materials.

The forming of the second insulating spacer may include: forming a first liner covering a surface of the nanosheet; and forming a second liner on the first liner. The second liner may include a first portion contacting the first liner between the nanosheet and the fin type active area, and a second portion spaced apart from the first liner with an air space interposed between the first liner and the second liner, the air space being disposed between the nanosheet and the fin type active area.

The forming of the second insulating spacer may include: forming a first liner covering a surface of the nanosheet; forming a second liner on the first liner, wherein the second liner contacts the first liner between the nanosheet and the fin type active area; and forming a burial liner on the second liner. The burial liner may contact the second liner between the nanosheet and the fin type active area. The first liner, the second liner, and the burial liner may include different materials from each other.

A portion of the second insulating spacer contacting the source and drain region may include a material different from a material of the first insulating spacer.

According to another aspect of the inventive concept, there is provided a method of manufacturing an integrated circuit device, the method including forming a fin type active area and a nanosheet stack structure including a plurality of nanosheets, wherein the fin type active area protrudes from a substrate and extends in a first direction, and the nanosheet stack structure faces an upper surface of the fin type active area, and is spaced apart from the upper surface; forming a first insulating spacer on the nanosheet stack structure, the first insulating spacer defining a gate space; forming a plurality of second insulating spacers, each having a multilayer structure, in spaces between the plurality of nanosheets and a space between the upper surface of the fin type active area and a lowest nanosheet among the plurality of nanosheets; forming a source and drain region on the fin type active area, the source and drain region being connected to one end of the nanosheet stack structure and ends of the plurality of second insulating spacers; and forming a gate on the fin type active area, wherein the gate extends in a second direction, surrounds the plurality of nanosheets, and faces the source and drain region, and the plurality of second insulating spacers is between the gate and the source and drain region.

The forming of the plurality of second insulating spacers may include forming an upper second insulating spacer in a space between the plurality of nanosheets and a lower second insulating spacer in a space between the upper surface of the fin type active area and the lowest nanosheet among the plurality of nanosheets. A thickness of the upper second insulating spacer may be greater than a thickness of the lower second insulating spacer.

The forming of the plurality of second insulating spacers may include forming insulating structures in spaces between the plurality of nanosheets and a space between the upper surface of the fin type active area and the lowest nanosheet among the plurality of nanosheets, each of the insulating structures including an air space.

The insulating structures may include two insulating liners including different materials and the air space interposed between the two insulating liners.

The insulating structures may include three insulating liners including different materials from each other.

According to another aspect of the inventive concept, an integrated circuit device comprises a substrate, a fin type active area that protrudes from the substrate, a plurality of source and drain regions on the fin type active area, a plurality of nanosheets that are adjacent to the plurality of source and drain regions, the plurality of source and drain regions being respectively connected to opposing ends of the plurality of nanosheets, and a plurality of insulating spacers disposed between ones of the plurality of nanosheets, each of the insulating spacers having a multi-layer structure.

The multi-layer structure may comprise at least one of an air space, SiN, SiCN, SiBN, SiON, SiOCN, SiBCN, SiOC, and SiO2.

The integrated circuit device may further comprise a gate comprising a main gate portion and a plurality of sub-gate portions. The main gate portion is on the plurality of nanosheets and the plurality of sub-gate portions is between the fin type active area and the plurality of nanosheets.

The plurality of insulating spacers may be a plurality of nanosheet insulating spacers and the integrated circuit device may further comprise: insulating liners on sidewalls of the main gate portion, gate insulating spacers on sidewalls on the insulating liners, and protection layers on the insulating liners. The gate insulating spacers and the nanosheet insulating spacers comprise different materials.

The multi-layer structure may comprise a first liner, a second liner, and an air space. The first liner is disposed between a respective one of the plurality of sub-gate portions, and the second liner and the air space is at least partially limited by the second liner. The first liner and the second liner comprise different materials.

The first liner may not comprise oxygen and the second liner may have an oxygen content from about 0 to about 50 atom %.

The multi-layer structure may comprise a first liner, a second liner, and a burial layer. The first liner is disposed between a respective one of the plurality of sub-gate portions, and the second liner and the burial layer fills a space at least partially limited by the second liner. The first liner, the second liner, and the burial layer may comprise different materials.

The first liner may not comprise oxygen and the second liner and the burial layer each may have an oxygen content from about 0 to about 50 atom %.

The multi-layer structure may comprise a first liner, a second liner, an air space and a partial burial layer. The first liner is disposed between a respective one of the plurality of sub-gate portions, and the second liner and the air space is at least partially limited by the second liner and the partial burial layer. The first liner, the second liner, and the partial burial layer comprise different materials.

The first liner may not comprise oxygen and the second liner and the partial burial layer may each have an oxygen content from about 0 to about 50 atom %.

It is noted that aspects of the inventive concepts described with respect to one embodiment, may be incorporated in a different embodiment although not specifically described relative thereto. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination. These and other aspects of the inventive concepts are explained in detail in the specification set forth below.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, the inventive concept will be described in detail by explaining embodiments of the invention with reference to the attached drawings. Like reference numerals in the drawings denote like elements, and, thus, their description will be omitted. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

The inventive concept may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. In the drawings, lengths and sizes of layers and areas may be exaggerated for clarity.

As used herein, the singular terms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it may be directly connected or coupled to the other element or intervening elements may be present.

Similarly, it will be understood that when an element such as a layer, region or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present. In contrast, the term “directly” means that there are no intervening elements. Additionally, the embodiments in the detailed description will be described with sectional views as ideal exemplary views of the inventive concepts. Accordingly, shapes of the exemplary views may be modified according to manufacturing techniques and/or allowable errors. Therefore, the embodiments of the inventive concepts are not limited to the specific shape illustrated in the exemplary views, but may include other shapes that may be created according to manufacturing processes.

Furthermore, throughout this disclosure, directional terms such as “upper,” “intermediate,” “lower,” and the like may be used herein to describe the relationship of one element or feature with another, and the inventive concept should not be limited by these terms. Accordingly, these terms such as “upper,” “intermediate,” “lower,” and the like may be replaced by other terms such as “first,” “second,” “third,” and the like to describe the elements and features.

Also, though terms like ‘first’ and ‘second’ are used to describe various elements, components, areas, layers, and/or portions in various embodiments of the inventive concept, the elements, components, areas, layers, and/or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another. Thus, a first element, component, area, layer or section discussed below could be termed a second element, component, area, layer or section without departing from the teachings of the inventive concept.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this inventive concept belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and this specification and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. As appreciated by the present inventive entity, devices and methods of forming devices according to various embodiments described herein may be embodied in microelectronic devices such as integrated circuits, wherein a plurality of devices according to various embodiments described herein are integrated in the same microelectronic device. Accordingly, the cross-sectional view(s) illustrated herein may be replicated in two different directions, which need not be orthogonal, in the microelectronic device. Thus, a plan view of the microelectronic device that embodies devices according to various embodiments described herein may include a plurality of the devices in an array and/or in a two-dimensional pattern that is based on the functionality of the microelectronic device.

The devices according to various embodiments described herein may be interspersed among other devices depending on the functionality of the microelectronic device. Moreover, microelectronic devices according to various embodiments described herein may be replicated in a third direction that may be orthogonal to the two different directions, to provide three-dimensional integrated circuits. Accordingly, the cross-sectional view(s) illustrated herein provide support for a plurality of devices according to various embodiments described herein that extend along two different directions in a plan view and/or in three different directions in a perspective view. For example, when a single active region is illustrated in a cross-sectional view of a device/structure, the device/structure may include a plurality of active regions and transistor structures (or memory cell structures, gate structures, etc., as appropriate to the case) thereon, as would be illustrated by a plan view of the device/structure.

When a certain embodiment can be embodied in a different manner, a specified process order may be performed in a different manner in order to be described. For example, two processes to be described sequentially may be substantially performed at the same time or may be performed in an order opposite to the order to be described.

As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the inventive concept should not be construed as limited to the particular shapes of areas illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. A term such as “substrate” may denote a substrate itself, or a stack structure including a substrate and predetermined layers or films formed on a surface of the substrate. In addition, a term “surface of substrate” may denote an exposed surface of the substrate itself, or an external surface of a predetermined layer or a film formed on the substrate. In the present specification, a term “nanosheet” may denote a two-dimensional structure having a thickness from about 1 to about 100 nm.

FIGS. 1A through 1Care diagrams illustrating an integrated circuit device100according to embodiments of the inventive concept, whereinFIG. 1Ais a plan layout diagram of main elements of the integrated circuit device100,FIG. 1Bis a cross-sectional view of the integrated circuit device100taken along a line X-X′ ofFIG. 1A, andFIG. 1Cis a cross-sectional view of the integrated circuit device100taken along a line Y-Y′ ofFIG. 1A.

Referring toFIGS. 1A through 1C, the integrated circuit device100may include a plurality of fin type active areas FA protruding from a substrate102and extending in a first direction (X direction) and a plurality of nanosheet stack structures NSS spaced apart from the upper surface104of the plurality of fin type active areas FA and facing an upper surface104of the plurality of fin type active areas FA.

A first trench T1defining the plurality of fin type active areas FA and a second trench T2defining a device area DR may be formed in the substrate102. The second trench T2may be deeper than the first trench T1.

Lower side walls of the plurality of fin type active areas FA may be covered by a shallow trench isolation (STI) layer114filling the first trench T1. The STI layer114may include an insulating liner114A conformally covering an inner wall of the first trench T1and a gap-fill insulating layer114B filling the first trench T1on the insulating liner114A. The second trench T2may be filled with a device isolation layer116. A level of the upper surface104of the plurality of fin type active areas FA, a level of an upper surface of the STI layer114, and a level of an upper surface of the device isolation layer132may be the same as or similar to each other.

A plurality of gates150may extend in a second direction (Y direction) crossing the first direction on the plurality of fin type active areas FA. The upper surface104of the plurality of fin type active areas FA may have a first level LV1.

The plurality of nanosheet stack structures NSS may be spaced apart from the upper surface104of the plurality of fin type active areas FA. The plurality of nanosheet stack structures NSS may include a plurality of nanosheets N1, N2, and N3extending in parallel to the upper surface104of the plurality of fin type active areas FA at a second level LV2farther than the first level LV1from the substrate102. The present example describes the configuration in which the plurality of nanosheet stack structures NSS and the plurality of gates150are formed on the single fin type active area FA, and the plurality of nanosheet stack structures NSS are arranged on the single fin type active area FA in a line along an extending direction (X direction) of the fin type active area FA but the inventive concept is not limited thereto. The number of the nanosheet stack structures NSS arranged on the single fin type active area FA is not be particularly limited. For example, the single nanosheet stack structure NSS may be formed on the single fin type active area FA.

The plurality of nanosheets N1, N2, and N3constituting the plurality of nanosheet stack structures NSS may be sequentially stacked on the upper surface104of the plurality of fin type active areas FA one by one. The present example describes a case where the single nanosheet stack structure NSS includes the three nanosheets N1, N2, and N3, but the inventive concept is not limited thereto. For example, each of the three nanosheets N1, N2, and N3may include one nanosheet, and may include a plurality of nanosheets that are variously selected if necessary. Each of the plurality of nanosheets N1, N2, and N3may include a channel area.

The plurality of gates150may be formed to surround at least some of the plurality of nanosheets N1, N2, and N3while covering the nanosheet stack structures NSS. Each of the plurality of gates150may include a main gate portion150M covering an upper surface of the nanosheet stack structures NSS and a plurality of sub-gate portions150S formed in a space between the fin type active areas FA and the nanosheets N1, N2, and N3. A thickness of each of the plurality of sub-gate portions150S may be smaller than a thickness of the main gate portion150M. In this regard, the thicknesses of the plurality of sub-gate portions150S and the thickness of the main gate portion150M refer to thicknesses in a Z direction inFIGS. 1A through 1C.

A gate dielectric layer145may be formed between the nanosheet stack structures NSS and the gates150.

The plurality of nanosheets N1, N2, and N3may be formed in an overlap region OR covered by the gates150in spaces between the fin type active areas FA and the gates150. In an X-Y plane, the nanosheet stack structures NSS including the plurality of nanosheets N1, N2, and N3may have a larger plane area than a plane area of the overlap region OR.FIG. 1Ashows a case where plane shapes of the nanosheet stack structures NSS are approximately rectangular shapes, but the inventive concept is not limited thereto. The nanosheet stack structures NSS may have various plane shapes according to plane shapes of the fin type active areas FA and plane shapes of the gates150.

The substrate102may include semiconductors, such as Si and Ge, or compound semiconductors, such as SiGe, SiC, GaAs, InAs, and InP. In some embodiments, the substrate102may include at least one of a group III-V material and a group IV material. The group III-V material may include a binary, a trinary, or a quaternary compound including at least one group III element and at least one group V element. The group III-V material may be a compound including at least one element of In, Ga, and Al as the group III element and at least one element of As, P, and Sb as the group V element. For example, the group III-V material may be selected from InP, InzGa1-zAs (0≤z≤1), and AlzGa1-zAs (0≤z≤1). The binary compound may be one of, for example, InP, GaAs, InAs, InSb and GaSb. The trinary compound may be one of InGaP, InGaAs, AlInAs, InGaSb, GaAsSb and GaAsP. The group IV material may be Si or Ge. However, the embodiments of the inventive concept are not limited to the above examples of the group III-V material and the group IV material. The group III-V material and the group IV material, such as Ge, may be used as channel materials for forming a transistor having a low power consumption and a high operating speed. A high performance complementary metal oxide semiconductor (CMOS) may be fabricated by using a semiconductor substrate including the group III-V material, e.g., GaAs, having a higher electron mobility than that of an Si substrate, and a semiconductor substrate having a semiconductor material, e.g., Ge, having a higher hole mobility than that of the Si substrate. In some embodiments, when an NMOS transistor is formed on the substrate102, the substrate102may include one of the group III-V materials described above. In some other embodiments, when a PMOS transistor is formed on the substrate102, at least a part of the substrate102may include Ge. In other embodiments, the substrate102may have a silicon-on-insulator (SOI) structure. The substrate102may include a conductive area, for example, a well doped with impurities or a structure doped with impurities.

In some embodiments, the plurality of nanosheets N1, N2, and N3may include a single material. In some embodiments, the plurality of nanosheets N1, N2, and N3may be formed of the same material as that of the substrate102.

In some embodiments, the gap-fill insulating layer114B may include an oxide layer. In some embodiments, the gap-fill insulating layer114B may include an oxide layer formed through a deposition process or a coating process. In some embodiments, the gap-fill insulting layer114B may include an oxide layer formed through a flowable chemical vapour deposition (FCVD) process or a spin coating process. For example, the gap-fill insulting layer114B may include fluoride silicate glass (FSG), undoped silicate glass (USG), boro-phospho-silicate glass (BPSG), phospho-silicate glass (PSG), flowable oxide (FOX), plasma enhanced tetra-ethyl-ortho-silicate (PE-TEOS), or tonen silazene (TOSZ), but is not limited thereto.

The device isolation layer116filled in the second trench T2may include an oxide layer, a nitride layer, or a combination thereof. In some embodiments, the device isolation layer116and the gap-fill insulting layer114B may include the same material.

The gate dielectric layer145may have a stack structure of an interfacial layer and a high dielectric layer. The interfacial layer may cure an interface defect between the upper surface104of the plurality of fin type active areas FA and surfaces of the plurality of nanosheets N1, N2, and N3and the high dielectric layer. In some embodiments, the interfacial layer may include a low dielectric material layer having a dielectric constant of 9 or less, e.g., a silicon oxide layer, a silicon oxynitride layer, or a combination thereof. In some other embodiments, the interfacial layer may include silicate, a combination of the silicate and a silicon oxide layer, or a combination of the silicate and a silicon oxynitride layer. In some embodiments, the interfacial layer may be omitted. The high dielectric layer may include a material having a dielectric constant greater than that of the silicon oxide layer. For example, the high dielectric layer may have a dielectric constant of about 10 to about 25. The high dielectric layer may include a material selected from hafnium oxide, hafnium oxynitride, hafnium silicon oxide, lanthanum oxide, lanthanum aluminum oxide, zirconium oxide, zirconium silicon oxide, tantalum oxide, titanium oxide, barium strontium titanium oxide, barium titanium oxide, strontium titanium oxide, yttrium oxide, aluminum oxide, lead scandium tantalum oxide, lead zinc niobate, and a combination thereof, but is not limited thereto. The high dielectric layer may be formed by an atomic layer deposition (ALD), a chemical vapour deposition (CVD), or physical vapor deposition (PVD) process. The high dielectric layer may have a thickness ranging from about 10 Å to about 40 Å, but is not limited thereto.

The gates150may include a layer containing metal for adjusting a work function, and a layer containing metal for filling a gap formed on an upper portion of the layer containing metal for adjusting the work function. In some embodiments, the gates150may have a structure in which a metal nitride layer, a metal layer, a conductive capping layer, and a gap-fill metal layer are sequentially stacked. The metal nitride layer and the metal layer may each include at least one metal material selected from Ti, W, Ru, Nb, Mo, Hf, Ni, Co, Pt, Yb, Tb, Dy, Er, and Pd. The metal nitride layer and the metal layer may be formed by an ALD process, a metal organic ALD (MOALD) process, or a metal organic CVD (MOCVD) process. The conductive capping layer may act as a protective layer for preventing or reducing oxidation of a surface of the metal layer. In addition, the conductive capping layer may act as a wetting layer for making a deposition of another conductive layer on the metal layer easy. The conductive capping layer may include a metal nitride layer, e.g., TiN, TaN, or a combination thereof, but is not limited thereto. The gap-fill metal layer may extend on the conductive capping layer. The gap-fill metal layer may include a W layer. The gap-fill metal layer may be formed by the ALD, the CVD, or the PVD process. The gap-fill metal layer may embed a recess space formed by a step between areas on an upper surface of the conductive capping layer without a void. In some embodiments, the gates150may include a stack structure of TiAlC/TiN/W, a stack structure of TiN/TaN/TiAlC/TiN/W, or a stack structure of TiN/TaN/TiN/TiAlC/TiN/W. In the above stack structures, a TiAlC layer or a TiN layer may function as a layer containing metal for adjusting the work function.

A plurality of source and drain regions162may be formed on the fin-type active areas FA. The plurality of source and drain regions162may be respectively connected to ends of the plurality of nanosheets N1, N2, and N3that are adjacent to the plurality of source and drain regions162.

The plurality of source and drain regions162may include a semiconductor layer162A that is epitaxially grown from the plurality of nanosheets N1, N2, and N3. The source and drain regions162may have an embedded SiGe structure including a Si layer that is epitaxially grown, an SiC layer that is epitaxially grown, and a plurality of SiGe layers that are epitaxially grown. The plurality of source and drain regions162may further include a metal silicide layer162B formed on the semiconductor layer162A. In some embodiments, the metal silicide layer162B may include titanium silicide, but is not limited thereto. In some embodiments, the metal silicide layer162B may be omitted.

Insulating liners134, first insulating spacers136, and protection layers138that sequentially cover sidewalls of the gates150may be formed on the plurality of nanosheet stack structures NSS. The protection layers138may extend to cover the plurality of source and drain regions162. The insulating liners134, the first insulating spacers136, and the protection layers138may include silicon nitride layers but are not limited thereto. In some embodiments, the protection layers138may be omitted.

The insulating liners134, the first insulating spacers136, and the protection layers138may cover a sidewall of the main gate portion150M included in the gates150.

Second insulating spacers140contacting the source and drain regions162may be formed in spaces between the plurality of nanosheets N1, N2, and N3. The second insulating spacers140may be disposed between the sub-gate portions150S and the source and drain regions162in the spaces between the plurality of nanosheets N1, N2, and N3. The second insulating spacers140may cover sidewalls of at least some of the plurality of sub-gate portions150S. In the integrated circuit device100illustrated inFIG. 1B, both side walls of the two sub-gate portions150S, excluding the sub-gate portion150S closest to the fin type active areas FA, among the three sub-gate portions150S may be covered by the second insulating spacers140. As illustrated inFIG. 1B, both side walls of the sub-gate portion150S closest to the fin type active areas FA among the three sub-gate portions150S may be covered by a buffer semiconductor layer106covering the upper surface104of the fin type active areas FA. The buffer semiconductor layer106may include a material different from materials of the fin type active areas FA and the plurality of nanosheets N1, N2, and N3. For example, the fin type active areas FA may include Si, and the buffer semiconductor layer106may include Ge.

The first insulating layers136and the second insulating spacer140may include different materials. In some embodiments, the first insulating spacers136may include a silicon nitride layer, and the second insulating spacers140may include a silicon nitride layer further including an oxygen (O) atom, boron (B) atom, a carbon (C) atom, or atoms including a combination thereof. In some other embodiments, the first insulating spacers136may include an insulating layer in which seeding and epitaxial growth of a semiconductor atom are impossible on its surface, and the second insulating spacers140may include an insulating layer in which seeding and epitaxial growth of a semiconductor atom are possible on at least a part of its surface. For example, the first insulating spacer136may include a SiN layer, and the second insulating spacers140may include a SiON layer. The SiON layer may be formed in contact with the semiconductor layer162A of the source and drain regions162.

In some embodiments, at least some of the plurality of second insulating spacers140may include an air space.

The plurality of second insulating spacers140may have a multilayer structure. In some embodiments, the plurality of second insulating spacers140may include at least one insulator selected from an air space, SiN, SiCN, SiBN, SiON, SiOCN, SiBCN, SiOC, and SiO2. For example, the plurality of second insulating spacers140may have at least a triple layer structure. A part of the at least a triple layer structure may be the air space.

FIGS. 2A through 2Care cross-sectional views of configurations of second insulating spacers140A,140B, and140C of various multilayer structures that may be used as the second insulating spacers140of the integrated circuit device100according to embodiments of the inventive concept, by expanding a portion corresponding to an area II inFIG. 1B.

As shown inFIG. 2A, the second insulating spacer140A may include a first liner142A, a second liner144A, and an air space AS1.

The first liner142A may have a surface facing the sub-gate portion150S of the gate150and a surface facing at least one of a plurality of nanowires N1, N2, and N3, and may include a first insulating material that does not include oxygen.

The second liner144A may be spaced apart from the sub-gate portion150S and the nanowires N1, N2, and N3with the first liner142A interposed therebetween and may include a second insulating material different from the first insulating material.

The air space AS1may be partially limited by the second liner144A.

In some embodiments, the first liner142A may include one of SiN, SiCN, and SiBN, and the second liner144A may include one of SiON, SiOCN, and SiBCN.

In some embodiments, the first insulating material constituting the first liner142A may not include oxygen, and the second insulating material constituting the second liner144A may have oxygen content ranging from about 0 to about 50 atom %.

As shown inFIG. 2B, the second insulating spacer140B may include a first liner142B, a second liner144B, and a burial layer146B.

The first liner142B may have a surface facing the sub-gate portion150S of the gate150and a surface facing at least one of the plurality of nanowires N1, N2, and N3, and may include the first insulating material that does not include oxygen.

The second liner144B may be spaced apart from the sub-gate portion150S and the nanowires N1, N2, and N3with the first liner142B interposed therebetween and may include the second insulating material different from the first insulating material.

The burial layer146B may fill at least a part of a space limited by the second liner142B and may include a third insulating material different from the second insulating material.

In some embodiments, the first liner142B may include one of SiN, SiCN, and SiBN, and the second liner144B and the burial layer146B may include different materials selected from SiON, SiOCN, and SiBCN.

In some embodiments, the first insulating material constituting the first liner142B may not include oxygen, and the second and third insulating materials respectively constituting the second liner144B and the burial layer146B may have oxygen content ranging from about 0 to about 50 atom %.

As shown inFIG. 2C, the second insulating spacer140C may include a first liner142C, a second liner144C, an air space AS2, and a partial burial layer146C.

The first liner142C may have a surface facing the sub-gate portion150S of the gate150and a surface facing at least one of the plurality of nanowires N1, N2, and N3, and may include the first insulating material that does not include oxygen.

The second liner144C may be spaced apart from the sub-gate portion150S and the nanowires N1, N2, and N3with the first liner142C interposed therebetween and may include the second insulating material different from the first insulating material.

The air space AS2may be partially limited by the second liner144C.

The partial burial layer146C along with the second liner144C may limit the air space AS2.

In some embodiments, the first liner142C may include one of SiN, SiCN, and SiBN, and the second liner144C and the partial burial layer146C may include different materials selected from SiON, SiOCN, and SiBCN.

In some embodiments, the first insulating material constituting the first liner142C may not include oxygen, and materials constituting the second liner144C and the partial burial layer146C may have oxygen content ranging from about 0 to about 50 atom %.

Referring toFIGS. 1A through 1C, an inter-gate insulating layer172and an interlayer insulating layer174may be sequentially formed on the plurality of source/drain regions162. The inter-gate insulating layer172and an interlayer insulating layer174may include a silicon nitride layer, but are not limited thereto.

A contact plug190may be connected to each of the plurality of source and drain regions162. The contact plug190may pass through the interlayer insulating layer174, the inter-gate insulating layer172, and the protection layer138and may be connected to the plurality of source and drain regions162. The metal silicide layer162B may be disposed between the semiconductor layer162A and the contact plug190. The contact plug190may include metal, conductive metal nitride, or a combination thereof. For example, the contact plug190may include W, Cu, Al, Ti, Ta, TiN, TaN, an alloy thereof, or a combination thereof, but is not limited thereto. Embodiments of the inventive concept are not limited to the above materials.

The integrated circuit device100described with reference toFIGS. 1A through 2Cabove may include the plurality of second insulating spacers140contacting the source and drain regions162in spaces between the plurality of nanosheets N1, N2, and N3formed on the fin type active areas FA. The plurality of second insulting spacers140may be formed as a multilayer structure or may be formed to include air spaces, and, thus, capacitance between the sub-gate portions150S of the gates150present in spaces between the plurality of nanosheets N1, N2, and N3and the source and drain regions162may be reduced, thereby reducing effective switching capacitance Ceff.

FIG. 3is a cross-sectional view of an integrated circuit device200according to other embodiments of the inventive concept. The integrated circuit device200illustrated inFIG. 3may have the same layout as shown in the plan layout diagram illustrated inFIG. 1A.FIG. 3illustrates a cross-sectional view taken along line X-X′ ofFIG. 1A. InFIG. 3, the same reference numerals are used to denote the same elements as inFIGS. 1A through 2C, and detailed descriptions thereof are omitted.

The integrated circuit device200illustrated inFIG. 3may generally have the same configuration as the integrated circuit device100illustrated inFIGS. 1A through 1C, except that the integrated circuit device200may not include the buffer semiconductor layer106illustrated inFIG. 1B. In the integrated circuit device200, the sub-gate portions150S may also be formed not only in spaces between the plurality of nanosheets N1, N2, and N3but also in spaces between the fin type active areas FA and the nanosheet N1. The plurality of second insulating spacers140and a plurality of second insulating spacers240may include the plurality of second insulating spacers140formed in the spaces between the plurality of nanosheets N1, N2, and N3and the second insulating spacers240formed in contact with the source and drain regions162in the spaces between the fin type active areas FA and the nanosheet N1. The second insulating spacers140and240may be disposed between the sub-gate portions150S and the source and drain regions162in spaces between the upper surface104of the fin type active areas FA and the plurality of nanosheets N1, N2, and N3. The second insulating spacers140and240may cover side walls of the plurality of sub-gate portions150S. A thickness of the second insulating spacer240that is the closest to the substrate102among the second insulating spacers240may be greater than a thickness of the other second insulating spacers140. A more detailed configuration of the second insulating spacers240is generally the same as that of the second insulating spacers140described with reference toFIGS. 1A through 2C.

FIGS. 4A through 4Care cross-sectional views of configurations of second insulating spacers140A,140B,140C,240A,240B, and240C of various multilayer structures that may be used as the second insulating spacers140and240of the integrated circuit device200according to other embodiments, by expanding a portion corresponding to an area IV indicated inFIG. 3. InFIGS. 4A through 4C, the same reference numerals are used to denote the same elements as inFIGS. 1A through 3, and detailed descriptions thereof are omitted.

The second insulating spacer240A ofFIG. 4Amay include a first liner242A, a second liner244A, and an air space AS21.

The first liner242A may have a surface facing the sub-gate portion150S that is the closest to the fin type active area FA among the plurality of sub-gate portions150S of the gate150, a surface facing the nanowire N1that is the closest to the fin type active area FA among the plurality of nanowires N1, N2, and N3, and a surface facing the fin type active area FA, and may include a first insulating material that does not include oxygen.

The second liner244A may be spaced apart from the fin type active area FA, the sub-gate portion150S, and the nanowire N1with the first liner242A interposed therebetween and may include a second insulating material different from the first insulating material.

The air space AS21may be partially limited by the second liner244A.

More detailed descriptions of the first liner242A and the second liner244A are generally the same as described regarding the first liner142A and the second liner144A with reference toFIG. 2A.

The second insulating spacer240B ofFIG. 4Bmay include a first liner242B, a second liner244B, and a burial layer246B.

The first liner242B may have a surface facing the sub-gate portion150S that is the closest to the fin type active area FA among the plurality of sub-gate portions150S of the gate150, a surface facing the nanowire N1that is the closest to the fin type active area FA among the plurality of nanowires N1, N2, and N3, and a surface facing the fin type active area FA, and may include a first insulating material that does not include oxygen.

The second liner244B may be spaced apart from the fin type active area FA, the sub-gate portion150S, and the nanowire N1with the first liner242B interposed therebetween and may include the second insulating material different from the first insulating material.

The burial layer246B may fill at least a part of a space limited by the second liner242B and may include a third insulating material different from the second insulating material.

More detailed descriptions of the first liner242B, the second liner244B, and the burial layer246B are generally the same as described regarding the first liner142b, the second liner144B, and the burial layer146B with reference toFIG. 2B.

The second insulating spacer240C ofFIG. 4Cmay include a first liner242C, a second liner244C, an air space AS22, and a partial burial layer246C.

The first liner242C may have a surface facing the sub-gate portion150S that is the closest to the fin type active area FA among the plurality of sub-gate portions150S of the gate150, a surface facing the nanowire N1that is the closest to the fin type active area FA among the plurality of nanowires N1, N2, and N3, and a surface facing the fin type active area FA, and may include a first insulating material that does not include oxygen.

The second liner244C may be spaced apart from the fin type active area FA, the sub-gate portion150S, and the nanowire N1with the first liner242C interposed therebetween and may include the second insulating material different from the first insulating material.

The air space AS22may be partially limited by the second liner244C.

The partial burial layer246C along with the second liner244C may limit the air space AS22.

More detailed descriptions of the first liner242C, the second liner244c, the air space AS22, and the partial burial layer246C are generally the same as described regarding the first liner142C, the second liner144C, the air space AS2, and the partial burial layer146C with reference toFIG. 2C.

The integrated circuit device200described with reference toFIGS. 3 through 4Cabove may include the plurality of second insulating spacers140and240contacting the source and drain regions162in not only spaces between the plurality of nanosheets N1, N2, and N3but also spaces between the fin type active areas FA and the nanosheet N1. The plurality of second insulting spacers140and240may be formed as a multilayer structure or some of the plurality of second insulting spacers140and240may be configured as air spaces, and, thus, capacitance between the sub-gate portions150S of the gates150present in spaces between the fin type active areas FA and the plurality of nanosheets N1, N2, and N3and the source and drain regions162may be reduced, thereby reducing effective switching capacitance Ceff.

FIGS. 5 through 26are cross-sectional views illustrating a method of manufacturing the integrated circuit device100based on a process order, according to embodiments of the inventive concept. The method of manufacturing the integrated circuit device100illustrated inFIGS. 1A through 1Cwill be described with reference toFIGS. 5 through 26. InFIGS. 5 through 26,FIGS. 5, 6A, 7A, 8A, 9A, 10A, 11A, 12 through 14, 15A, 16A and 17 through 26are cross-sectional views of portions corresponding to cross-sections taken along the line X-X′ ofFIG. 1A, andFIGS. 6B, 7B, 8B, 9B, 10B, and 11Bare cross-sectional views of portions corresponding to cross-sections taken along the line Y-Y′ ofFIG. 1A. InFIGS. 5 through 26, the same reference numerals are used to denote the same elements as inFIGS. 1A through 2C, and detailed descriptions thereof are omitted.

Referring toFIG. 5, a plurality of sacrifice semiconductor layers106S and a plurality of nanosheet semiconductor layers NS may be alternately stacked on the substrate102.

The plurality of sacrifice semiconductor layers106S and the plurality of nanosheet semiconductor layers NS may include different semiconductor materials. In some embodiments, the plurality of sacrifice semiconductor layers106S may include SiGe, and the plurality of nanosheet semiconductor layers NS may include Si, but embodiments of the inventive concept are not limited thereto.

A thickness of the sacrifice semiconductor layer106S that is the closest to the substrate102among the plurality of sacrifice semiconductor layers106S may be greater than those of the other sacrifice semiconductor layers106S, but is not limited thereto. For example, the sacrifice semiconductor layers106S may have the same thickness.

Referring toFIGS. 6A and 6B, a mask pattern MP may be formed on a stack structure of the plurality of sacrifice semiconductor layers106S and the plurality of nanosheet semiconductor layers NS.

The mask pattern MP may include a plurality of line patterns extending in parallel to each other in one direction (X direction).

The mask pattern MP may include a pad oxide layer pattern512and a hard mask pattern514. The hard mask pattern512may include silicon nitride, polysilicon, a spin-on hardmask (SOH) material, or a combination thereof, but is not limited thereto. In some embodiments, the SOH material may include a hydrocarbon compound having a relatively high carbon content ranging from about 85 w % to about 99 w % in relation to the total weight of the SOH material or derivatives thereof.

Referring toFIGS. 7A and 7B, the stack structure of the sacrifice semiconductor layers106S and the plurality of nanosheet semiconductor layers NS may be formed by using the mask pattern MP as an etch mask and the plurality of first trenches T1may be formed by etching a part of the substrate102. As a result, the plurality of fin type active areas FA defined by the plurality of first trenches T1may be formed.

After the plurality of fin type active areas FA is formed, the stack structure of the sacrifice semiconductor layers106S and the plurality of nanosheet semiconductor layers NS may remain on the plurality of fin type active areas FA.

Referring toFIGS. 8A and 8B, the STI layer114including the insulating liner114A and the gap-fill insulating layer114B may be formed in the plurality of first trenches Ti.

Referring toFIGS. 9A and 9B, the second trench T2defining the device area DR (seeFIG. 1A) may be formed by etching a partial structure from a resultant structure formed from the plurality of fin type active areas FA and the STI layer114, and the device isolation layer116may be formed in the second trench T2.

Referring toFIGS. 10A and 10B, the mask pattern MP remaining on the stack structure of the plurality of sacrifice semiconductor layers106S and the plurality of nanosheet semiconductor layers NS may be removed, and a recess process may be performed to remove upper portions of the STI layer114and the device isolation layer116equal to partial thicknesses thereof.

The recess process may be performed on an upper surface of each of the STI layer114and the device isolation layer116to be approximately the same as or similar to a level of the upper surface104of the fin type active area FA. As a result, side walls of the stack structure of the sacrifice semiconductor layers106S and the plurality of nanosheet semiconductor layers NS present on the plurality of fin type active areas FA may be exposed.

Dry etching, wet etching, or a combination of dry etching and wet etching may be used to perform the recess process.

In some embodiments, after the mask pattern MP is removed, before the recess process is performed to remove the upper portions of the STI layer114and the device isolation layer116, an impurity ion injection process for injecting impurity ions for adjusting threshold voltages may be performed on the upper portions of the plurality of nanosheet semiconductor layers NS and the plurality of fin-type active areas FA. In some embodiments, during the impurity ion injection process for injecting impurity ions for adjusting threshold voltages, boron (B) ions may be injected into an area in which an NMOS transistor is formed as impurities, and phosphor (P) or arsenide (As) ions may be injected into an area in which a PMOS transistor is formed as impurities.

Referring toFIGS. 11A and 11B, a plurality of dummy gate structures DGS extending across the plurality of fin-type active areas FA may be formed on the plurality of fin-type active areas FA.

The dummy gate structures DGS may have a structure in which an oxide layer D152, a dummy gate layer D154, and a capping layer D156are sequentially stacked. In an example of forming the dummy gate structures DGS, the oxide layer D152, the dummy gate layer D154, and the capping layer D156may be sequentially formed to respectively cover an exposed surface of the stack structure of the plurality of sacrifice semiconductor layers106S and the plurality of nanosheet semiconductor layers NS that cover the plurality of fin type active areas FA, an upper surface of the STI layer114, and an upper surface of the device isolation layer116and then patterned, and, thus, the oxide layer D152, the dummy gate layer D154, and the capping layer D156may be maintained only where necessary. The dummy gate structures DGS may be formed to have a planar shape corresponding to a planar shape of the gates150illustrated inFIG. 1A.

In some embodiments, the dummy gate layer D154may include polysilicon, and the capping layer D156may include a silicon nitride layer, but, embodiments of the inventive concept are not limited thereto.

Referring toFIG. 12, the insulating liner134may be formed to cover an exposed surface of the dummy gate structures DGS, the exposed surface of the stack structure of the plurality of sacrifice semiconductor layers106S and the plurality of nanosheet semiconductor layers NS, and the upper surface of each of the STI layer114and the device isolation layer116.

In some embodiments, the insulating liner134may include a silicon nitride layer.

In some embodiments, after the insulating liner134is formed, a halo implantation region may be formed in the plurality of nanosheet semiconductor layers NS by injecting impurity ions in the plurality of nanosheet semiconductor layers NS. To form the halo implantation region, boron (B) ions may be injected into an area in which an NMOS transistor is formed as impurities, and phosphor (P) or arsenide (As) ions may be injected into an area in which a PMOS transistor is formed as impurities.

Referring toFIG. 13, the first insulating spacers136covering both side walls of the dummy gate structures DGS may be formed, a part of the stack structure of the plurality of sacrifice semiconductor layers106S and the plurality of nanosheet semiconductor layers NS may be removed by etching by using the dummy gate structures DGS and the first insulating spacers136as an etching mask, and the plurality of nanosheet stack structures NSS including the plurality of nanosheets N1, N2, and N3may be formed from the plurality of nanosheet semiconductor layers NS.

To form the first insulating spacers136, after a spacer layer including a silicon nitride layer may be formed on a resultant structure ofFIG. 12in which the insulating liner134is formed, the first insulating spacers136may remain by etching back the spacer layer again.

When the stack structure of the plurality of sacrifice semiconductor layers106S and the plurality of nanosheet semiconductor layers NS is etched, an etching process may be performed by using a point where the sacrifice semiconductor layer106S that is the lowest layer among the plurality of sacrifice semiconductor layer106S is exposed as an etching end point. Accordingly, after the plurality of nanosheet stack structures NSS is formed, the sacrifice semiconductor layers106S covering the fin type active areas FA may be exposed between the plurality of nanosheet stack structures NSS. After the plurality of nanosheet stack structures NSS is formed, the sacrifice semiconductor layers106S may remain between the fin type active area FA and the plurality of nanosheet stack structures NSS and between the plurality of nanosheets N1, N2, and N3.

Referring toFIG. 14, an isotropic etching process may be used to form recess regions106R between the plurality of nanosheets N1, N2, and N3by removing some of the plurality of sacrifice semiconductor layers106S exposed at both sides of each of the plurality of nanosheet stack structures NSS.

During the formation of the recess regions106R, a part of an upper surface of an exposed portion of the lowest sacrifice semiconductor layer106S covering the fin type active areas FA may be removed between the plurality of nanosheets N1, N2, and N3.

In some embodiments, the isotropic etching process for forming the recess regions106R may be performed through a wet etching process that uses a difference in an etch selectivity between the plurality of sacrifice semiconductor layers106S and the plurality of nanosheet stack structures NSS.

Referring toFIG. 15A, an insulating structure140L including the plurality of second insulating spacers140filling the recess regions106R (seeFIG. 14) formed between the plurality of nanosheet stack structures NSS may be formed.

In some embodiments, the insulating structure140L may include a plurality of insulating layers.

FIGS. 15B through 15Dare cross-sectional views of various insulating structures140L1,140L2, and140L3that are employable as the insulating structure140L including the plurality of second insulating spacers140, by expanding a portion corresponding to an area P1ofFIG. 15A.

In some embodiments, to form the insulating structure140L including the second insulating spacers140illustrated inFIG. 15A, the insulating structure140L1including the second insulating spacer140A illustrated inFIG. 15Bmay be formed.

The insulating structure140L1may include the first liner142A and the second liner144A that are sequentially formed from inner side walls of the recess region106R (seeFIG. 14). The insulating structure140L1may further include the air space AS1limited by the second liner144A in the recess region106R.

To form the first liner142A and the second liner144A, an ALD process, a CVD process, an oxidation process, or a combination thereof may be used. To form the air space AS1limited by the second liner144A in the recess region106R, a step coverage characteristic may be controlled during a deposition process for forming the second liner144A. The second liner144A may be formed to include a portion contacting the first liner142A between the plurality of nanosheet stack structures NSS and a portion spaced apart from the first liner142A having the air space AS1therebetween between the plurality of nanosheet stack structures NSS.

More detailed descriptions of the first liner142A and the second liner144A are the same as described with reference toFIG. 2Aabove.

In some other embodiments, to form the insulating structure140L including the second insulating spacers140illustrated inFIG. 15A, the insulating structure140L2including the second insulating spacer140B illustrated inFIG. 15Cmay be formed.

The insulating structure140L2may include the first liner142B, the second liner144B, and the burial layer146B that are sequentially formed from inner side walls of the recess region106R (seeFIG. 14). The first liner142B, the second liner144B, and the burial layer146B may include different materials.

To form the first liner142B, the second liner144B, and the burial layer146B, an ALD process, a CVD process, an oxidation process, or a combination thereof may be used.

More detailed descriptions of the first liner142B, the second liner144B, and the burial layer146B are the same as described with reference toFIG. 2Babove.

In some other embodiments, to form the insulating structure140L including the second insulating spacers140illustrated inFIG. 15A, the insulating structure140L3including the second insulating spacer140C illustrated inFIG. 15Dmay be formed.

The insulating structure140L3may include the first liner142C, the second liner144C, and the partial burial layer146C that are sequentially formed from inner side walls of the recess region106R (seeFIG. 14). The insulating structure140L3may further include the air space AS2limited by the second liner144C and the partial burial layer146C in the recess region106R.

To form the first liner142C, the second liner144C, and the partial burial layer146C, an ALD process, a CVD process, an oxidation process, or a combination thereof may be used.

In an example of forming the air space AS2, a step coverage characteristic may be controlled during a deposition process for forming the partial burial layer146C such that the air space AS2may remain in the recess region106R.

More detailed descriptions of the first liner142C, the second liner144C, and the partial burial layer146C are the same as described with reference toFIG. 2Cabove.

Referring toFIG. 16A, the second insulating spacer140filling the recess region106R may remain by removing a portion of the insulating structure140L (seeFIG. 15A) outside the recess region106R (seeFIG. 14).

FIGS. 16B through 16Dare cross-sectional views of various configurations obtained after removing the portion of the insulating structure140L outside the recess region106R (seeFIG. 14) by expanding a portion corresponding to an area P2ofFIG. 16A.

In some embodiments, as shown inFIG. 16B, the second insulating spacer140A remaining in the recess region106R (seeFIG. 14) after removing the portion of the insulating structure140L outside the recess region106R (seeFIG. 14) may include the first liner142A and the second liner144A. The second insulating spacer140A may further include the air space AS1limited by the first liner142A and the second liner144A.

In some embodiments, as shown inFIG. 16C, the second insulating spacer140B remaining in the recess region106R (seeFIG. 14) after removing the portion of the insulating structure140L outside the recess region106R (seeFIG. 14) may include the first liner142B, the second liner144B, and the burial layer146B.

In some embodiments, as shown inFIG. 16D, the second insulating spacer140C remaining in the recess region106R (seeFIG. 14) after removing the portion of the insulating structure140L outside the recess region106R (seeFIG. 14) may include the first liner142C, the second liner144C, and the partial burial layer146C. The second insulating spacer140C may further include the air space AS2limited by the second liner144C and the partial burial layer146C.

Referring toFIG. 16A, after removing the portion of the insulating structure140L illustrated inFIG. 15Aoutside the recess region106R (seeFIG. 14), both side walls of the nanowires N1, N2, and N3, the plurality of second insulating spacers140, and the sacrifice semiconductor layer106S that is the lowest layer among the plurality of sacrifice semiconductor layers106S may be exposed.

Referring toFIG. 17, the exposed side walls of the nanowires N1, N2, and N3and the exposed surface of the sacrifice semiconductor layer106S that is the lowest layer among the plurality of sacrifice semiconductor layers106S may be exposed in a cleaning atmosphere148, and, thus, a natural oxide layer may be removed from the exposed both side walls and the exposed surfaces.

In some embodiments, a first cleaning process using a wet cleaning process, a second cleaning process using a SiCoNi™ etching process, or a combination thereof may be used as the cleaning atmosphere148. During the wet cleaning process, DHF (diluted HF), NH4OH, TMAH (tetramethyl ammonium hydroxide), KOH (potassium hydroxide) solution, etc. may be used. The SiCoNi™ etching process may be performed using a hydrogen source of ammonia NH3and a fluorine source of nitrogen trifluoride NF3.

During a cleaning process for removing the natural oxide layer, insulating layers constituting the second insulating spacers140, in particular, insulating layers exposed to the cleaning atmosphere148, may be configured as materials having an etching resistance with respect to the cleaning atmosphere148, and, thus, the second insulating spacers140may not be consumed during the removing of the natural oxide layer under the cleaning atmosphere148. More details of appropriate insulating materials constituting the second insulating spacers140are the same as described with reference toFIGS. 2A through 2C.

Referring toFIG. 18, the semiconductor layer162A for forming the source and drain regions162(seeFIG. 1B) may be formed by epitaxially growing a semiconductor material from both side walls exposed to the plurality of nanosheets N1, N2, and N3from which the natural oxide layer is removed.

As described with reference toFIGS. 1A through 1Cabove, the first insulating spacers136may include an insulating layer in which seeding and epitaxial growth of a semiconductor atom are impossible on its surface, and the second insulating spacers140may include an insulating layer in which seeding and epitaxial growth of a semiconductor atom are possible on at least a part of its surface, and thus an epitaxial growth process for forming the semiconductor layer162A may be performed not only on the exposed both side walls of the plurality of nanowires N1, N2, and N3but also on surfaces of the second insulating spacers140, thereby facilitating the formation of the semiconductor layer162A and forming the semiconductor layer162A having a good characteristic without a void.

Referring toFIG. 19, the protection layer138covering a resultant structure in which the semiconductor layer162A is formed may be formed.

In some embodiments, the protection layer138may include a silicon nitride layer. To form the protection layer138, the ALD process or the CVD process may be used.

Referring toFIG. 20, after the inter-gate insulating layer172is formed on the protection layer138, an upper surface of the capping layer D156may be exposed by planarizing the inter-gate insulating layer172.

Referring toFIG. 21, the capping layer D156(seeFIG. 20) covering an upper surface of the dummy gate layer D154, and the insulating liner134, the first insulating spacer136, and the protection layer138that surround the capping layer D156may be etched back, and an upper portion of the inter-gate insulating layer172may be polished to a depth equal to a partial thickness thereof, such that the upper surface of the inter-gate insulating layer172may be located at an approximately same level as that of the upper surface of the dummy gate layer D154.

Referring toFIG. 22, the dummy gate layer D154exposed through the inter-gate insulating layer172and the oxide layer D152present below the dummy gate layer D154may be removed, such that the nanosheet N3may be exposed through gate spaces GS.

Referring toFIG. 23, parts of the plurality of sacrifice semiconductor layers106S remaining on the fin type active area FA may be removed, such that the plurality of nanosheets N1, N2, and N3and the upper surface104of the fin type active area FA may be partially exposed through the gate spaces GS.

The sacrifice semiconductor layer106S that is the lowest layer among the plurality of sacrifice semiconductor layers106S may not be completely removed so that a part of the sacrifice semiconductor layer106S may remain on the fin type active area FA in a lower portion of the second insulating spacer140. A portion of the sacrifice semiconductor layer106S remaining on the fin type active area FA may constitute the buffer semiconductor layer106.

Referring toFIG. 24, after the natural oxide layer is removed from the exposed surfaces of the plurality of nanosheets N1, N2, and N3and the fin type active area FA, the gate dielectric layer145may be formed on surfaces exposed by the gate spaces GS (seeFIG. 23), and a gate forming conductive layer150L covering the inter-gate insulating layer172may be formed while filling the gate spaces GS on the gate dielectric layer145.

Referring toFIG. 25, a part of an upper surface of the gate forming conductive layer150L (seeFIG. 24) may be removed until an upper surface of the inter-gate insulating layer172is exposed, and the gate150filling the gate spaces GS may be formed.

The gate150may include the main gate portion150M covering an upper surface of the nanosheet stack structure NSS including the plurality of nanosheets N1, N2, and N3and the plurality of sub-gate portions150S connected to the main gate portion150M and formed in spaces between the plurality of nanosheets N1, N2, and N3.

Referring toFIG. 26, after an interlayer insulating layer174covering the gate150and the inter-gate insulating layer172is formed, the interlayer insulating layer174and the inter-gate insulating layer172may be partially etched so that a plurality of contact holes190H exposing the plurality of semiconductor layers162A may be formed. Thereafter, the metal silicide layer162B may be formed on an upper surface of the plurality of semiconductor layers162A exposed through the plurality of contact holes190H, and the plurality of contact plugs190respectively connected to the semiconductor layers162A through the metal silicide layer162B may be formed, and, thus, the integrated circuit device100illustrated inFIGS. 1A through 1Cmay be formed.

The method of manufacturing the integrated circuit device100described with reference toFIGS. 5 through 26above may be used to form the integrated circuit device100including the plurality of second insulating spacers140contacting the source and drain regions162in spaces between the plurality of nanosheets N1, N2, and N3. In particular, the plurality of second insulating spacers140may be formed as a multilayer structure, or the plurality of second insulating spacers140may be formed to include air spaces if necessary. Thus, capacitance between the sub-gate portions150S of the gates150and the source and drain regions162of the semiconductor layers162A may be reduced, thereby easily implementing a structure that may reduce effective switching capacitance Ceff.

FIGS. 27 through 31are cross-sectional views illustrating a method of manufacturing the integrated circuit device200based on a process order, according to other embodiments of the inventive concept. The method of manufacturing the integrated circuit device200illustrated inFIG. 3will now be described with reference toFIGS. 27 through 31. InFIGS. 27 through 31,FIGS. 27, 28, 29A, 30A, and 31are cross-sectional views of portions corresponding to cross-sections taken along the line X-X′ ofFIG. 3. InFIGS. 27 through 31, the same reference numerals are used to denote the same elements as inFIGS. 1A through 26, and detailed descriptions thereof are omitted.

Referring toFIG. 27, processes described with reference toFIGS. 5 through 13may be performed to form the plurality of nanosheet stack structures NSS including the plurality of nanosheets N1, N2, and N3on the fin type active area FA.

However, differently from described with reference toFIG. 13, in the present example, an etching process may be performed until an upper surface of the fin type active area FA is exposed when a stack structure of the plurality of sacrifice semiconductor layers106S and the plurality of nanosheet semiconductor layers NS is etched. Accordingly, after the plurality of nanosheet stack structures NSS is formed, the fin type active areas FA may be exposed between the plurality of nanosheet stack structures NSS.

Referring toFIG. 28, in the same manner as described with reference toFIG. 14above, some of the plurality of sacrifice semiconductor layers106S exposed at both sides of each of the plurality of nanosheet stack structures NSS may be removed, and, thus, the recess regions106R may be formed between the plurality of nanosheet stack structures NSS. However, in the present example, additional recess regions106R may be formed between the nanosheet N1that is the lowest layer of the plurality of nanosheet stack structures NSS and the fin type active area FA.

Referring toFIG. 29A, in a similar way as described with reference toFIG. 15A, the insulating structure140L including the plurality of second insulating spacers140and240filling the recess regions106R (seeFIG. 28) may be formed. A thickness of the second insulting spacer240formed in the recess region106R between the nanosheet N1that is the lowest layer and the fin type active area FA may be greater than a thickness of the second insulating spacer140formed in the recess region106R between the plurality of nanosheets N1, N2, and N3.

FIGS. 29B through 29Dare cross-sectional views of various insulating structures140L1,140L2, and140L3that may be used as the insulating structure140L including the plurality of second insulating spacers140and240, by expanding a portion corresponding to an area P3ofFIG. 29A.

In some embodiments, to form the insulating structure140L including the second insulating spacers140and240illustrated inFIG. 29A, in a similar way as described with reference toFIG. 15B, the insulating structure140L1including the second insulating spacer140A and240A illustrated inFIG. 29Bmay be formed.

The insulating structure140L1may be formed to include the air spaces AS1in spaces between the plurality of nanosheets N1, N2, and N3and a space between the upper surface of the fin type active area FA and the nanosheet N1that is the lowest layer among the plurality of nanosheets N1, N2, and N3. In the insulating structure140L1, the second insulating spacer240A formed in the recess region106R (seeFIG. 28) between the nanosheet N1that is the lowest layer among the plurality of nanosheets N1, N2, and N3and the fin type active area FA may have generally the same configuration as the second insulating spacers140A between the plurality of nanosheets N1, N2, and N3. However, a thickness of the second insulating spacer240A may be greater than a thickness of the second insulating spacer140A.

In some other embodiments, to form the insulating structure140L including the second insulating spacers140and240illustrated inFIG. 29A, in a similar way as described with reference toFIG. 15C, the insulating structure140L2including the second insulating spacer140B and240B illustrated inFIG. 29Cmay be formed. In the insulating structure140L2, the second insulating spacer240B formed in the recess region106R (seeFIG. 28) between the nanosheet N1that is the lowest layer among the plurality of nanosheets N1, N2, and N3and the fin type active area FA may have generally the same configuration as the second insulating spacers140B between the plurality of nanosheets N1, N2, and N3. However, a thickness of the second insulating spacer240B may be greater than a thickness of the second insulating spacer140B.

In some other embodiments, to form the insulating structure140L including the second insulating spacers140and240illustrated inFIG. 29A, in a similar way as described with reference toFIG. 15D, the insulating structure140L3including the second insulating spacer140C and240C illustrated inFIG. 29Dmay be formed.

The insulating structure140L3may be formed to include the air spaces AS2in spaces between the plurality of nanosheets N1, N2, and N3and a space between the upper surface of the fin type active area FA and the nanosheet N1that is the lowest layer among the plurality of nanosheets N1, N2, and N3. In the insulating structure140L3, the second insulating spacer240C formed in the recess region106R (seeFIG. 28) between the nanosheet N1that is the lowest layer among the plurality of nanosheets N1, N2, and N3and the fin type active area FA may have generally the same configuration as the second insulating spacers140C between the plurality of nanosheets N1, N2, and N3. However, a thickness of the second insulating spacer240C may be greater than a thickness of the second insulating spacer140C.

Referring toFIG. 30A, in a similar way as described with reference toFIG. 16A, the second insulating spacers140and240filling the recess regions106R may remain by removing portions of the insulating structure140L (seeFIG. 29A) outside the recess regions106R (seeFIG. 28).

FIGS. 30B through 30Dare cross-sectional views of various configurations obtained after removing the portions of the insulating structure140L outside the recess regions106R (seeFIG. 28), by expanding a portion corresponding to an area P4ofFIG. 30A.

Referring toFIGS. 30B through 30D, the second insulating spacers140A,140B, and140C may be formed in the recess regions106R (seeFIG. 28) between the plurality of nanosheets N1, N2, and N3, and the second insulating spacers240A,240B, and240C may be formed in the recess regions106R (seeFIG. 28) between the nanosheet N1that is the lowest layer among the plurality of nanosheets N1, N2, and N3and the fin type active area FA.

Referring toFIG. 31, processes described with reference toFIGS. 17 through 26may be performed on a resultant structure ofFIG. 30A, and, thus, the integrated circuit device200may be formed.

The method of manufacturing the integrated circuit device200described with reference toFIGS. 27 through 31above may be used to form the integrated circuit device200including the plurality of second insulating spacers140and240contacting the source and drain regions162in spaces between the plurality of nanosheets N1, N2, and N3and a space between the nanosheet N1that is the lowest layer among the plurality of nanosheets N1, N2, and N3and the fin type active area FA. In particular, the plurality of second insulating spacers140and240may be formed as a multilayer structure, or the plurality of second insulating spacers140and240may be formed to include air spaces if desired. Thus, capacitance between the sub-gate portions150S of the gates150and the source and drain regions162may be reduced, thereby implementing a structure for reducing effective switching capacitance Ceff.

Although the methods of manufacturing the integrated circuit device100illustrated inFIGS. 1A through 1Cand the integrated circuit device200illustrated inFIG. 3are described with reference toFIGS. 5 through 31above, it will be understood to one of ordinary skill in the art that various integrated circuit devices having similar structures to those of the integrated circuit devices100and200may be manufactured through various modifications and changes within the scope of the inventive concept.

Integrated circuit devices including transistors having nanosheet channel areas formed on three-dimensional structure fin type active areas and methods of manufacturing the integrated circuit devices are described with reference toFIGS. 1A through 31, but the embodiments of the inventive concept are not limited thereto. For example, it will be understood to one of ordinary skill in the art that integrated circuit devices including planar MOSFETs having characteristics of the embodiments of the inventive concept and methods of manufacturing the integrated circuit devices may be provided through various modifications and changes within the scope of the inventive concept.

FIG. 32is a block diagram of an electronic device1000according to embodiments of the inventive concept.

Referring toFIG. 32, the electronic device1000may include a logic area1010and a memory area1020.

The logic area1010may include various kinds of logic cells including a plurality of circuit elements, such as transistors, registers, etc., as standard cells performing desired logic functions, such as a counter, a buffer, etc. The logic cell may be configured to implement such logical functions as, e.g., AND, NAND, OR, NOR, XOR (exclusive OR), XNOR (exclusive NOR), INV (inverter), ADD (adder), BUF (buffer), DLY (delay), FILL (filter), multiplexer (MXT/MXIT), OAI (OR/AND/INVERTER), AO (AND/OR), AOI (AND/OR/INVERTER), D flip-flop, reset flip-flop, master-slaver flip-flop, latch, etc. However, the logic cells according to the embodiments of the inventive concept are not limited to the above examples.

The memory area1020may include at least one of SRAM, DRAM, MRAM, RRAM, and PRAM.

The logic area1010and the memory area1020may respectively include at least one of the integrated circuit devices100and200illustrated inFIGS. 1A through 4Cand other integrated circuit devices having various structures modified and changed from the above integrated circuit devices100and200within the scope of the inventive concept.

FIG. 33is a block diagram of an electronic system2000according to embodiments of the inventive concept.

Referring toFIG. 33, the electronic system2000may include a controller2010, an input/output (I/O) device2020, a memory2030, and an interface2040that are connected to one another via a bus2050.

The controller2010may include at least one of a microprocessor, a digital signal processor, and other similar processors. The I/O device2020may include at least one of a keypad, a keyboard, and a display. The memory2030may be used to store a command executed by the controller2010. For example, the memory2030may be used to store user data.

The electronic system2000may be used to configure a wireless communication device, or a device capable of transmitting and/or receiving information under a wireless communication environment. The interface2040may include a wireless interface in order to transmit/receive data via a wireless communication network in the electronic system2000. The interface2040may include an antenna and/or a wireless transceiver. In some embodiments, the electronic system2000may be used for a communication interface protocol of a third-generation communication system, e.g., code division multiple access (CDMA), global system for mobile communications (GSM), north American digital cellular (NADC), extended-time division multiple access (E-TDMA), and/or wide band code division multiple access (WCDMA). The electronic system2000may include at least one of the integrated circuit devices100and200illustrated inFIGS. 1A through 4Cand other integrated circuit devices having various structures modified and changed from the above integrated circuit devices100and200within the scope of the inventive concept.