The present inventive concept relates to semiconductor devices and methods of manufacturing semiconductor devices.
Semiconductor devices including three-dimensional FinFETs are being developed to overcome limitations in device characteristics (e.g. a short channel effect) due to the further miniaturization of the semiconductor devices. In order to improve the performance of semiconductor devices, methods of increasing charge carrier mobility and decreasing source/drain resistance are being studied.
Embodiments according to the inventive concept can provide semiconductor devices including varied depth recesses for contacts and methods of manufacturing the same. Pursuant to these embodiments, a first conductivity type finFET device can include first embedded sources/drains of a first material that have a first etch rate. The first embedded sources/drains can each include an upper surface having a recessed portion and an outer raised portion relative to the recessed portion. A second conductivity type finFET device can include second embedded sources/drains of a second material that have a second etch rate than is greater that the first etch rate. The second embedded sources/drains can each include an upper surface that is at a lower level than the raised portion of the first conductivity type finFET device.
In some embodiments according to the inventive concept, a semiconductor device, can include at least one active fin protruding from a substrate and a gate structure intersecting the at least one active fin. An embedded source/drain can be disposed on the active fin and include an upper surface having a recessed portion thereof that extends parallel to a direction in which the gate structure extends. A contact plug can partially cover the recessed portion, where the upper surface of the embedded source/drain can further include a raised portion relative to the recessed portion, where the raised portion can be located between the recessed portion and the gate structure.
In some embodiments according to the inventive concept, a method of manufacturing a semiconductor device, can include providing a substrate including first active fins, first sacrificial gates, and first sidewall spacers disposed in a first region, and second active fins, second sacrificial gates, and second sidewall spacers disposed in a second region. Second embedded sources/drains can be formed at both sides of the second sacrificial gates and first embedded sources/drains can be formed at both sides of the first sacrificial gates. A blocking insulating layer can be formed to cover the second embedded sources/drains and expose the first embedded sources/drains. The first embedded sources/drains can be etched using the first sidewall spacers as an etch mask to provide recessed portions of the first embedded sources/drains exposed by the first sidewall spacers. An etch-stop layer can be formed to cover the first sacrificial gates, the second sacrificial gates, the first embedded sources/drains, and the second embedded sources/drains. An interlayer insulating layer can be formed on the etch-stop layer and the interlayer insulating layer over the first and second embedded sources/drains can be simultaneously etched to provide first and second contact holes on the first and second embedded sources/drains, respectively.
In some embodiments according to the inventive concept, a method of manufacturing a semiconductor device can include providing first sacrificial gates and first sidewall spacers disposed in a first region of a substrate, and second sacrificial gates and second sidewall spacers disposed in a second region of the substrate and forming second embedded sources/drains comprising a second material at both sides of the second sacrificial gates. First embedded sources/drains can be formed to include a first material that is different from the second material, at both sides of the first sacrificial gates. A blocking insulating layer can be formed to cover the second embedded sources/drains and to expose the first embedded sources/drains. The first embedded sources/drains can be partially etched to provide recessed portions. An etch-stop layer can be formed on the first sacrificial gates, the second sacrificial gates, the first embedded sources/drains, and the second embedded sources/drains. A first interlayer insulating layer can be formed to expose upper surfaces of the first and second sacrificial gates on the etch-stop layer. The first and second sacrificial gates can be replaced with first and second gate structures, respectively. A second interlayer insulating layer can be formed to cover the first gate structures, the second gate structures, and the first interlayer insulating layer and the first and second interlayer insulating layers can be simultaneously etched to provide first contact holes that partially expose the first embedded sources/drains and to provide second contact holes that partially expose the second embedded sources/drains.
Example embodiments of the present inventive concept will now be described in detail with reference to the accompanying drawings.
The inventive concepts are described hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the inventive concepts are shown. The advantages and features of the inventive concepts and methods of achieving them will be apparent from the following exemplary embodiments that will be described in more detail with reference to the accompanying drawings. It should be noted, however, that the inventive concepts are not limited to the following exemplary embodiments, and may be implemented in various forms. Accordingly, the exemplary embodiments are provided only to disclose the inventive concepts and let those skilled in the art know the category of the inventive concepts. In the drawings, embodiments of the inventive concepts are not limited to the specific examples provided herein and are exaggerated for clarity.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. 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. 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. 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.
It will be also understood that although the terms first, second, third etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, a first element in some embodiments could be termed a second element in other embodiments without departing from the teachings of the present invention. Exemplary embodiments of aspects of the present inventive concepts explained and illustrated herein include their complementary counterparts. The same reference numerals or the same reference designators denote the same elements throughout the specification.
Moreover, exemplary embodiments are described herein with reference to cross-sectional illustrations and/or plane illustrations that are idealized exemplary illustrations. Accordingly, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, exemplary embodiments should not be construed as limited to the shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an etching region illustrated as a rectangle will, typically, have rounded or curved features. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of example embodiments.
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.
Referring to
The first transistors 100A may include first active fins 105, first gate structures 140, first sidewall spacers 150, first embedded sources/drains 110, and first contact plugs 180. The second transistors 100B may include second active fins 205, second gate structures 240, second sidewall spacers 250, second embedded sources/drains 210, a blocking insulating layer 252, and second contact plugs 280. The semiconductor device 100 may further include isolation layers 107 and 207, etch-stop layers 154 and 254, and contact spacers 170 and 270.
The first region I may be a region in which N-type FinFETs are formed, and the second region II may be a region in which P-type FinFETs are formed. That is, the first transistors 100A may be the N-type FinFETs, and the second transistors 100B may be the P-type FinFETs.
The substrate 101 may include an upper surface extending in an X-direction and a Y-direction. The substrate 101 may include a semiconductor material, such as a IV-group semiconductor, a III-V group compound semiconductor, or a II-VI compound semiconductor. For example, the substrate 101 may be a semiconductor substrate including silicon, germanium, or silicon-germanium, a silicon-on-insulator (SOI) substrate, or a germanium-on-insulator (GeOI) substrate.
The first and second active fins 105 and 205 may be disposed to extend in a first direction, such as the Y-direction on substrate 101. The first and second active fins 105 and 205 may have a structure of fins protruding from the substrate 101. The first and second active fins 105 and 205 may be formed by etching the substrate 101. In some example embodiments, the first and second active fins 105 and 205 may include an epitaxial layer grown from the substrate 101. For example, the first active fins 105 may be formed of silicon including P-type impurities, and the second active fins 205 may be formed of silicon including N-type impurities. The first active fins 105 and the second active fins 205 are illustrated as extending in the same direction, but are not limited thereto. The first active fins 105 and the second active fins 205 may extend in different directions.
The isolation layers 107 and 207 may be disposed between the first and second active fins 105 and 205. The isolation layers 107 and 207 may have a height to expose upper portions of the first and second active fins 105 and 205. The isolation layers 107 and 207 may be formed by a shallow trench isolation (STI) process, for example. The isolation layers 107 and 207 may be formed of an insulating material. The isolation layers 107 and 207 may include, for example, silicon oxide, silicon nitride, a low-k material, or a combination thereof. The low-k material may include boro-phospho-silicate glass (BPSG), tonen silazene (TOSZ), undoped silicate glass (USG), spin on glass (SOG), flowable oxide (FOX), tetra-ethyl-ortho-silicate (TEOS), or a high density plasma-CVD (HDP-CVD) oxide.
The first and second gate structures 140 and 240 may be disposed to substantially perpendicularly intersect the first and second active fins 105 and 205, respectively, and extend in a second direction such as in the X-direction on the substrate 101. Channel areas of transistors may be formed in the first and second active fins 105 and 205 intersecting the first and second gate structures 140 and 240. The first gate structures 140 and the second gate structures 240 are illustrated as extending in the same direction, but are not limited thereto. The first gate structures 140 and the second gate structures 240 may extend in different directions.
Each of the first gate structures 140 may include a first gate insulating layer 142, a first lower gate electrode 145, and a first upper gate electrode 147. The first gate insulating layer 142 may be disposed between the first active fins 105 and the first lower gate electrode 145. The first gate insulating layer 142 may extend to a space between the first sidewall spacer 150 and the first lower gate electrode 145. The first lower gate electrode 145 and the first upper gate electrode 147 may be sequentially disposed on the first gate insulating layer 142. Each of the second gate structures 240 may include a second gate insulating layer 242, a second lower gate electrode 245, and a second upper gate electrode 247. The second gate insulating layer 242 may be disposed between the second active fins 205 and the second lower gate electrode 245. The second gate insulating layer 242 may extend to a space between the second sidewall spacer 250 and the second lower gate electrode 245. The second lower gate electrode 245 and the second upper gate electrode 247 may be sequentially disposed on the second gate insulating layer 242.
The first and second gate insulating layers 142 and 242 may include silicon oxide, silicon oxynitride, silicon nitride, or a high-k material. The high-k material may be a dielectric material having a higher dielectric constant than silicon oxide (SiO2). The high-k material may include, for example, aluminum oxide (Al2O3), tantalum oxide (Ta2O3), titanium oxide (TiO2), yttrium oxide (Y2O3), zirconium oxide (ZrO2), zirconium silicon oxide (ZrSixOy), hafnium oxide (HfO2), hafnium silicon oxide (HfSixOy), lanthanum oxide (La2O3), lanthanum aluminum oxide (LaAlxOy), lanthanum hafnium oxide (LaHfxOy), hafnium aluminum oxide (HfAlxOy), or praseodymium oxide (Pr2O3). The first and second lower gate electrodes 145 and 245 may include, for example, at least one selected from the group consisting of titanium nitride (TiN), tantalum nitride (TaN), tungsten nitride (WN), titanium aluminum nitride (TiAlN), titanium aluminum (TiAl), tantalum carbide (TaC), and titanium carbide (TiC). The first and second upper gate electrodes 147 and 247 may include a metal material, such as aluminum (Al), tungsten (W), or molybdenum (Mo), or a semiconductor material such as doped polysilicon.
Each of the first and second sidewall spacers 150 and 250 may be disposed on both sidewalls of the first and second gate structures 140 and 240. The first sidewall spacers 150 may be disposed between the first embedded sources/drains 110 and the first gate structures 140. The second sidewall spacer 250 may be disposed between the second embedded sources/drains 210 and the second gate structure 240. The first and second sidewall spacers 150 and 250 may include silicon oxide, silicon nitride, silicon oxynitride, or a low-k material. The first and second sidewall spacers 150 and 250 may be formed of a multilayer. For example, the first and second sidewall spacers 150 and 250 may have a stacked structure of a silicon nitride layer and a low-k layer.
The first embedded sources/drains 110 may be disposed on the first active fins 105 at both sides of the first gate structures 140. More specifically, the first embedded sources/drains 110 may be formed on areas at which the first active fins 105 are recessed. The first embedded sources/drains 110 may be provided as source areas or drain areas of the first transistors 100A. The first embedded sources/drains 110 may be elevated sources/drains whose upper surfaces are disposed higher than lower surfaces of the first gate structures 140. Each of the first embedded sources/drains 110 may have a merged or a connected structure on the first active fins 105. The number of the first active fins 105 may not be limited to that illustrated in
Each of the first embedded sources/drains 110 may include a recessed portion RS parallel to the first gate structure 140. That is, each of the first embedded sources/drains 110 may include the recessed portion RS extending parallel to the direction in which the first gate structure 140 extends. The recessed portion RS may be disposed throughout the upper surface of the first embedded source/drain 110 in the direction in which the first gate structure 140 extends. The recessed portion RS may be formed to be spaced apart from the first sidewall spacer 150 by a particular distance. The recessed portion RS may have a shape to which the shape of the upper surface of the first embedded source/drain 110 is transferred. Each of the first embedded sources/drains 110 may include a raised portion relative to a recessed portion RS and the raised portion located between the recessed portion and the first gate structure 140.
The first embedded sources/drains 110 may be epitaxial layers grown by a selective epitaxial growth process. The first embedded sources/drains 110 may include, for example, silicon or silicon carbide (SiC) in which N-type impurities are doped with a high concentration.
The second embedded sources/drains 210 may be disposed at both sides of the second gate structures 240 on areas at which the second active fins 205 are recessed. The second embedded sources/drains 210 may be provided as source areas or drain areas of the second transistors 100B. Upper surfaces of the second embedded sources/drains 210 may be formed to have substantially the same height as lower surfaces of the second gate structures 240. In some example embodiments, the second embedded sources/drains 210 may be elevated sources/drains whose upper surfaces are disposed higher than the lower surfaces of the second gate structures 240. Upper surfaces of the second embedded sources/drains 210 may be at a different level from the outer raised portions of the first embedded sources/drains 110. For example, upper surfaces of the second embedded sources/drains 210 may be at a lower level from the outer raised portions of the first embedded sources/drains 110. Each of the second embedded sources/drains 210 may have a connected or merged structure on the second active fins 205. The number of the connected second active fins 205 is not limited to that illustrated in
The second embedded sources/drains 210 may be epitaxial layers grown by a selective epitaxial growth process. The second embedded sources/drains 210 may include, for example, silicon-germanium (SiGe) in which P-type impurities are doped with a high concentration. For example, when the second embedded sources/drains 210 include silicon-germanium (SiGe), compressive stress may be applied to channel areas, portions of the second active fins 205 formed of silicon (Si). Accordingly, hole mobility in the channel areas may be improved.
The blocking insulating layer 252 may be formed to have a substantially uniform thickness on the second sidewall spacers 250, isolation layers 207, and second embedded sources/drains 210 disposed on the substrate 101. The etch-stop layer 254 may be disposed to have a substantially uniform thickness on the blocking insulating layer 252. The blocking insulating layer 252 may be formed of silicon nitride, silicon oxynitride, or a combination thereof.
The etch-stop layers 154 and 254 may have substantially uniform thicknesses on the first and second sidewall spacers 150 and 250, the isolation layers 107 and 207, the first and second embedded sources/drains 110 and 210, and the recessed portions RS formed in the first embedded sources/drains 110, disposed on the substrate 101. The etch-stop layers 154 and 254 may be formed of silicon nitride, silicon oxynitride, or a combination thereof.
The first and second contact plugs 180 and 280 may be respectively disposed on the first and second embedded sources/drains 110 and 210 and may have elongated horizontal cross-sections. In other words, the first and second contact plugs 180 and 280 may have a shape elongated in directions in which the first and second gate structures 140 and 240 extend (such as in the X-direction). In addition, the first and second contact plugs 180 and 280 may have rectangular or oval shapes when viewed in a plan view.
The first contact plugs 180 may pass through the etch-stop layer 154 to be connected to the first embedded sources/drains 110. The first contact plugs 180 may be disposed to cover portions of the recessed portions RS of the first embedded sources/drains 110. The etch-stop layer 154 may remain on the recessed portions RS on which the first contact plugs 180 are not formed. Widths (for example, sizes in the Y-direction) of the first contact plugs 180 may not be the same as widths of the recessed portions RS. When the widths of the first contact plugs 180 are narrower than the widths of the recessed portions RS, the etch-stop layer 154 may remain between the first contact plugs 180 and side surfaces of the recessed portions RS (refer to
The second contact plugs 280 may pass through the etch-stop layer 254 and the blocking insulating layer 252 to connect to the second embedded sources/drains 210.
The first and second contact plugs 180 and 280 may include first conductive layers 184 and 284 and second conductive layers 186 and 286. The first conductive layers 184 and 284 may be conformally formed on lower surfaces and sidewalls of the first and second contact plugs 180 and 280. The first conductive layers 184 and 284 may include, for example, at least one of metal nitrides such as titanium nitride (TiN), tantalum nitride (TaN), and tungsten nitride (WN). The second conductive layers 186 and 286 may include a conductive material such as aluminum (Al), copper (Cu), tungsten (W), or molybdenum (Mo).
Silicide layers 182 and 282 may be disposed between the first contact plugs 180 and the first embedded sources/drains 110, and between the second contact plugs 280 and the second embedded sources/drains 210 (refer to
Referring to
The first active fins 105 may be formed in the first region by forming mask patterns on the substrate 101 and etching the substrate 101 by using the mask patterns as etch masks, and the second active fins 205 may be formed in the second region. Trenches may be formed between the first and second active fins 105 and 205 by the etching process. The isolation layers 107 and 207 may be formed by filling lower portions of the trenches with an insulating material. As a result, upper portions of the first and second active fins 105 and 205 may protrude above the isolation layers 107 and 207.
After forming a gate insulating layer and a gate electrode layer covering the first and second active fins 105 and 205, the first gate mask patterns 136 may be formed in the first region, and the second gate mask patterns 236 may be formed in the second region. The gate insulating layer and the gate electrode layer may be anisotropically etched using the first and second gate masks 136 and 236 as etch masks. Thereby, the first sacrificial gate insulating layers 132 and the first sacrificial gates 135 extending to intersect the first active fins 105 may be formed in the first region, and the second sacrificial gate insulating layers 232 and the second sacrificial gates 235 extending to intersect the second active fins 205 may be formed in the second region. For example, the first and second sacrificial gate insulating layers 132 and 232 may include silicon oxide, and the first and second sacrificial gates 135 and 235 may include polysilicon.
The first sidewall spacers 150 may be formed on the sidewalls of the first sacrificial gates 135, and the second sidewall spacers 250 may be formed on the sidewalls of the second sacrificial gates 235, by forming an insulating layer covering the first and second sacrificial gates 135 and 235 and the first and second active fins 105 and 205 and performing an etchback process. The first and second sidewall spacers 150 and 250 may include silicon oxide, silicon nitride, or silicon oxynitride. The first and second sidewall spacers 150 and 250 are illustrated as being formed in a single layer, but are not limited thereto. The first and second sidewall spacers 150 and 250 may be formed in multilayers.
Fin recesses may be formed at both sides of the second sidewall spacers 250 by selectively etching the second active fins 205 after forming a protection layer covering the first region of the substrate 101. The second embedded sources/drains 210 filling the fin recesses may be formed using a selective epitaxial growth (SEG) process. Upper surfaces of the second embedded sources/drains 210 are illustrated as being formed substantially at the same level as upper surfaces of the second active fins 205, but are not limited thereto. In some example embodiments, the upper surfaces of the second embedded sources/drains 210 may be formed higher than the upper surfaces of the second active fins 205. The second embedded sources/drains 210 may be, for example, a silicon germanium (SiGe) layer. Although the second embedded sources/drains 210 are illustrated as a single layer, the second embedded sources/drains 210 may include two or more silicon germanium layers having different germanium concentrations. During the process of growing the second embedded sources/drains 210, P-type impurities such as boron (B) may be in-situ doped. The second embedded sources/drains 210 may be formed to have a merged structure while growing on the second active fins 205.
The protection layer covering the first region of the substrate 101 may be removed, and the blocking insulating layer 252 covering the second region of the substrate 101 may be formed. The blocking insulating layer 252 may be conformally formed to have a substantially uniform thickness on surfaces of the second embedded sources/drains 210, the second gate mask patterns 236, and the second sidewall spacers 250. The blocking insulating layer 252 may be formed of, for example, silicon nitride.
Fin recesses may be formed by selectively etching portions of the first active fins 105 at both sides of the first sidewall spacers 150 in the first region. The first embedded sources/drains 110 filling the fin recesses may be formed using an SEG process. Upper surfaces of the first embedded sources/drains 110 are illustrated as being formed higher than upper surfaces of the first active fins 105, but are not limited thereto. The first embedded sources/drains 110 may be formed of a different material from the second embedded sources/drains 210. The first embedded sources/drains 110 may be, for example, a silicon (Si) layer. During the process of growing the first embedded sources/drains 110, N-type impurities such as phosphors (P) may be in-situ doped. The first embedded sources/drains 110 may be formed to have a merged structure while growing on the first active fins 105.
Referring to
Third sidewall spacers 153 and 253 may be formed by forming an insulating layer having a given thickness and covering both of the first region and second region in the substrate 101 and performing an etchback process. The third sidewall spacers 153 formed in the first region may be disposed on one sides of the first sidewall spacers 150 to partially cover the upper surfaces of the first embedded sources/drains 110. The third sidewall spacers 153 and 253 may be formed of, for example, silicon oxide. The third sidewall spacers 153 and 253 may be formed by an atomic layer deposition (ALD) process.
The recessed portions RS spaced apart from the first sidewall spacers 150 at a given distance may be formed by selectively removing portions of the first embedded sources/drains 110 by using the third sidewall spacers 153 formed in the first region as etch masks. The distance between the recessed portions RS and the first sidewall spacers 150 may be determined by a thickness of the third sidewall spacers 153. That is, the recessed portions RS may be formed at locations spaced apart from the first sidewall spacers 150 by the thickness of the third sidewall spacers 153. The recessed portions RS may be formed to have a given depth D1 from the upper surfaces of the first embedded sources/drains 110. The recessed portion RS may have a shape to which a shape of the upper surfaces of the first embedded sources/drains 110 is transferred.
Accordingly, in some embodiments, when the first contact holes C1 and the second contact holes C2 are simultaneously formed to expose the first and second embedded sources/drains 110 and 210 by patterning interlayer insulating layers (refer to
As appreciated by the present inventors, during an etching process by which the contact holes C1 and C2 are simultaneously formed on the first and second embedded sources/drains 110 and 210, upper portions of the first and second embedded sources/drains 110 and 210 may be partially removed. Here, when the second embedded sources/drains 210 are silicon germanium layers and the first embedded sources/drains 110 are silicon layers, an etching rate of the first embedded sources/drains 110 may be less than that of the second embedded sources/drains 210. Thus, the depths of the contact recesses RSC1 formed on the first embedded sources/drains 110 may be shallower than depths of contact recesses RSC2 formed on the second embedded sources/drains 210. When a contact recess is shallow, a contact area of a contact plug formed therein may be small and contact resistance of the contact plug may increase.
Therefore, by forming the recessed portions RS in the first embedded sources/drains 110 first, and forming recesses in the process of etching the contact holes according to an example embodiment, the depth of the contact recesses RSC1 of the first contact holes C1 may be independently adjusted to a desired level. Further, the contact resistance of the contact plugs may be reduced. A depth of the recessed portion RS of the first embedded sources/drains 110 is selected to compensate for a difference between the etching rate of the first embedded sources/drains 110 and the etching rate of second embedded sources/drains 210.
Referring to
In the first region, the etch-stop layer 154 may be formed to have a given thickness on the first sidewall spacers 150, the recessed portions RS, and the first embedded sources/drains 110. In the second region, the etch-stop layer 254 may be formed to have a given thickness on the blocking insulating layer 252, The etch-stop layers 154 and 254 may be formed of silicon nitride. The etch-stop layers 154 and 254 may be formed by an ALD process.
Referring to
The first interlayer insulating layers 162 and 262 may be formed by forming an insulating layer on the etch-stop layers 154 and 254 and performing a planarization process to expose the upper surfaces of the first and second sacrificial gates 135 and 235. Accordingly, the first and second gate masks 136 and 236 may be removed in this process. Alternatively, in some example embodiments, the first and second gate masks 136 and 236 may remain on the first and second sacrificial gates 135 and 235, and the remaining first and second gate masks 136 and 236 may be removed in a subsequent process.
The first interlayer insulating layers 162 and 262 may include boro-phospho-silicate glass (BPSG), tonen silazene (TOSZ), undoped silicate glass (USG), spin on glass (SOG), flowable oxide (FOX), tetra-ethyl-ortho-silicate (TEOS), or a high density plasma-CVD (HDP-CVD) oxide. The first interlayer insulating layers 162 and 262 may be formed by a chemical vapor deposition (CVD) process, a plasma enhanced-CVD (PE-CVD) process, a spin coating process, or an ALD process.
Referring to
The first and second sacrificial gate insulating layers 132 and 232, and the first and second sacrificial gates 135 and 235 may be removed. The first and second sacrificial gate insulating layers 132 and 232, and the first and second sacrificial gates 135 and 235 may be selectively removed with respect to the isolation layers 107 and 207 and first and second active fins 105 and 205 disposed thereunder, to form openings partially exposing the isolation layers 107 and 207 and the first and second active fins 105 and 205. The process of removing the first and second sacrificial gate insulating layers 132 and 232 and the first and second sacrificial gates 135 and 235 may include at least one of a dry etching process and a wet etching process.
The first gate structures 140 and the second gate structures 240 may be formed by sequentially forming first and second gate insulating layers 142 and 242, first and second lower gate electrodes 145 and 245, and first and second upper gate electrodes 147 and 247 in the openings, and performing a planarization process. In some example embodiments, the first lower gate electrodes 145 and the second lower gate electrodes 245 may include different materials. In this case, an additional deposition and etching process may be used.
The second interlayer insulating layers 164 and 264 may be formed by forming an insulating layer covering the first interlayer insulating layers 162 and 262 and the gate structures 140 and 240 and performing a planarization process. The second interlayer insulating layers 164 and 264 may include boro-phospho-silicate glass (BPSG), tonen silazene (TOSZ), undoped silicate glass (USG), spin on glass (SOG), flowable oxide (FOX), tetra-ethyl-ortho-silicate (TEOS), or a high density plasma-CVD (HDP-CVD) oxide. The second interlayer insulating layers 164 and 264 may be formed by a CVD process, a PE-CVD process, a spin coating process, or an ALD process.
Referring to
The first interlayer insulating layers 162 and 262 and the second interlayer insulating layers 164 and 264 may be etched using a mask pattern such as a photoresist pattern, to form preliminary contact holes partially exposing the etch-stop layers 154 and 254. Next, an insulating layer may be conformally formed on inner surfaces of the preliminary contact holes. The insulating layer may also be formed on the exposed etch-stop layers 154 and 254.
The first contact holes C1 partially exposing the first embedded sources/drains 110 may be formed by etching the insulating layer and the etch-stop layer 154 retained in lower portions of the preliminary contact holes in the first region using an additional etching process. Here, the contact spacers 170 may be formed on the sidewalls of the first contact holes C1. In addition, the second contact holes C2 partially exposing the second embedded sources/drains 210 may be formed by etching the insulating layer, the etch-stop layer 254, and the blocking insulating layer 252 retained in lower portions of the preliminary contact holes in the second region using the additional etching process. Here, the contact spacers 270 may be formed on the sidewalls of the second contact holes C2. The etching process for forming the first and second contact holes C1 and C2 may be simultaneously performed.
While the first contact holes C1 are formed, upper portions of the first embedded sources/drains 110 having the recessed portions RS may be partially etched to form the contact recesses RSC1. Since the first contact holes C1 are formed on the recessed portions RS of the first embedded sources/drains 110, the first embedded sources/drains 110 may be additionally etched from lower surfaces of the recessed portions RS to form the contact recesses RSC1 having a first depth DC1. While the second contact holes C2 are formed, upper surfaces of the second embedded sources/drains 210 may be partially etched to form the contact recesses RSC2 having a second depth DC2. For example, respective bottoms of the first and second contact holes C1 and C2 are about level with one another. That is, respective bottoms of the first and second contact plugs (180 and 280 in
Referring to
The first and second contact holes C1 and C2 may be filled by sequentially depositing first conductive layers 184 and 284 and second conductive layers 186 and 286. The first and second contact plugs 180 and 280 may be formed by performing a planarization process to expose upper surfaces of the second interlayer insulating layers 164 and 264. Silicide layers 182 and 282 formed between the first and second contact plugs 180 and 280 and the embedded sources/drains 110 and 210 may include a metal silicide formed by a reaction of the first conductive layers 184 and 284 with the embedded sources/drains 110 and 210 in this process or in a subsequent process. Alternatively, the silicide layers 182 and 282 may include a metal silicide formed by a reaction of another metal material with the embedded sources/drains.
Referring to
Referring to
Although the method of forming the recessed portions RS in the first embedded sources/drains 110 using a dry etching process is described with reference to
Referring to
After performing the processes described with reference to
Referring to
Referring to
Referring to
Referring to
Third sidewall spacers 153 and 253 may be formed by forming an insulating layer covering the entire first and second regions of the substrate 101 and performing an etchback process. The sacrificial oxide layers 160′ may be formed by performing an oxidation process on the first embedded sources/drains 110 exposed between the third sidewall spacers 153 in the first region. The sacrificial oxide layers 160′ may include bird's beaks formed under the third sidewall spacers 153. The sacrificial oxide layers 160′ may have smaller thicknesses than the sacrificial oxide layers 160 described with reference to
Referring to
Referring to
The first transistors 300A may include first active fins 105, first gate structures 140, first sidewall spacers 150, first embedded sources/drains 110a, and first contact plugs 180, and the second transistor 300B may include second active fins 205, second gate structures 240, second sidewall spacers 250, second embedded sources/drains 210a, and second contact plugs 280. Although structures formed on the substrate 101 are similar to those illustrated in
In the example embodiment of the present inventive concept, the first embedded sources/drains 110a may have a connected or merged structure on three first active fins 105. Different from those illustrated in
Similarly, the second embedded sources/drains 210a may have a connected or merged structure on three second active fins 205. Different from those illustrated in
The number of active fins may not be limited to that illustrated in
Referring to
Although structures formed on the substrate 101 are similar to those illustrated in
The first transistors 400A may include one first active fin 105 and first embedded sources/drains 110b disposed on the one first active fin 105, and the second transistor 400B may include one second active fin 205, second gate structures 240, second sidewall spacers 250, second embedded sources/drains 210b, and second contact plugs 280.
The number of active fins may not be limited to that illustrated in
In the example embodiment of the present inventive concept, the first and second embedded sources/drains 110b and 210b are illustrated as having a pentagonal structure, but are not limited thereto. The first and second embedded sources/drains 110b and 210b may have a variety of shapes.
Referring to
Referring to
In addition, the first pull-down transistor TN1 including an NMOSFET and the first pull-up transistor TP1 including a PMOSFET may be connected in series to configure a first inverter, and the second pull-down transistor TN2 including an NMOSFET and the second pull-up transistor TP2 including a PMOSFET may be connected in series to configure a second inverter. An output terminal of the first inverter may be connected to a source of the first pass transistor TN3, and an output terminal of the second inverter may be connected to a source of the second pass transistor TN4. In addition, input terminals and output terminals of the first and second inverters may be cross-coupled to provide a latch circuit. In addition, drains of the first and second pass transistors TN3 and TN4 may be respectively connected to first and second bit-lines BL and /BL. Gates of the first and second pass transistors TN3 and TN4 may be connected to a word-line WL. The transistors may be formed of the above-described semiconductor devices according to various example embodiments of the present inventive concept.
Referring to
Referring to
The communication unit 2010 may include a wired/wireless communications module, such as a wireless internet module, a short-range communications module, a GPS module, or a mobile communications module. The wired/wireless communications module included in the communication unit 2010 may be connected to an external communications network by a variety of communications standards to transmit and receive data. The input unit 2020 is a module supplied for a user to control an operation of the electronic apparatus 2000, and includes a mechanical switch, a touchscreen, a voice recognition module, or the like. In addition, the input unit 2020 may include a trackball, a laser pointer mouse, or a finger mouse, and may further include a variety of sensor modules in which a user can input data. The output unit 2030 may output information processed by the electronic apparatus 2000 in an audio or video form. The memory 2040 may store a program for processing or controlling of the processor 2050, data, or the like. The processor 2050 may write data or read data by transmitting a command to the memory 2040 according to a requested operation. The memory 2040 may be embedded in the electronic apparatus 2000 or communicate with the processor 2050 through a separate interface. When the memory 2040 communicates with the processor 2050 through the separate interface, the processor 2050 may write data to or read data from the memory 2040 by a variety of interface standards, such as SD, SDHC, SDXC, MICRO SD, or USB. The processor 2050 may control operations of each unit included in the electronic apparatus 2000. The processor 2050 may perform controlling or processing operations related to voice calls, video calls, or data communication, or controlling or processing operations for multimedia playback and management. In addition, the processor 2050 may process an input transmitted through the input unit 2020 from a user, and output a result thereof through the output unit 2030. Further, the processor 2050 may write data used to control operations of the electronic apparatus 2000 to the memory 2040, or read the data from the memory 2040, as described above. At least one of the processor 2050 or the memory 2040 may include the above-described semiconductor devices according to various example embodiments of the present inventive concept.
Referring to
As set forth above, according to the example embodiments of the present inventive concept, a method of manufacturing a semiconductor device may be provided. According to the method of the present inventive concept, depths of recessed portions of contact holes can be independently controlled in the N-type transistor and the P-type transistor while simultaneously forming the contact holes. In addition, a semiconductor device having excellent electrical characteristics may be provided.
While example embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations could be made without departing from the scope of the invention as defined by the appended claims.
Number | Date | Country | Kind |
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10-2015-0073726 | May 2015 | KR | national |
This application is a continuation of U.S. patent application Ser. No. 15/150,917, filed May 10, 2016, which itself claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2015-0073726 filed on May 27, 2015, with the Korean Intellectual Property Office, the disclosures of both of which are hereby incorporated by reference in their entireties.
Number | Date | Country | |
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Parent | 15150917 | May 2016 | US |
Child | 15916513 | US |