Abstract: A method for fabricating FinFETs is described. A semiconductor substrate is patterned to form odd fins. Spacers are formed on the substrate and on the sidewalls of the odd fins, wherein each spacer has a substantially vertical sidewall. Even fins are then formed on the substrate between the spacers. A semiconductor structure for forming FinFETs is also described, which is fabricated using the above method.

Abstract: Disclosed herein are various methods of forming metal silicide regions on semiconductor devices by using different temperatures during the silicidation processes. In one example, the method includes forming a plurality of N-doped source/drain regions and a plurality of P-doped source/drain regions in a semiconducting substrate and performing a first heating process at a first temperature to initially form a first metal silicide region in each of the P-doped source/drain regions. The method further includes performing a second heating process at a second temperature to initially form a second metal silicide region in each of the N-doped source/drain regions, wherein the second temperature is less than the first temperature and performing a third heating process at a third temperature to complete the formation of the first and second metal silicide regions, wherein the third temperature is greater than the first temperature.

Abstract: A MOSFET is described incorporating a common metal process to make contact to the source, drain and the metal gate respectively which may be formed concurrently with the same metal or metals.

Abstract: A semiconductor device in which a metal silicide layer is formed by a salicide process is improved in reliability. By a salicide process according to a partial reaction method, metal silicide layers are formed over respective surfaces of gate electrodes, n+-type semiconductor regions, and p+-type semiconductor regions. In a first heat treatment when the metal silicide layers are formed, a heat-conduction type anneal apparatus is used for the heat treatment of a semiconductor wafer. In a second heat treatment, a microwave anneal apparatus is used for the heat treatment of the semiconductor wafer, thereby reducing the temperature of the second heat treatment and preventing abnormal growth of the metal silicide layers. Thus, a junction leakage current in the metal silicide layers is reduced.

Abstract: An integrated circuit device and method for manufacturing the integrated circuit device is disclosed. The disclosed method provides a processing for forming improved source/drain features in the semiconductor device. Semiconductor devices with the improved source/drain features may prevent or reduce defects and achieve high strain effect resulting from epi layers. In an embodiment, the source/drain features comprises a second portion surrounding a first portion, and a third portion between the second portion and the semiconductor substrate, wherein the second portion has a composition different from the first and third portions.

Abstract: In a multiple gate transistor, the plurality of Fins of the drain or source of the transistor are electrically connected to each other by means of a common contact element, wherein enhanced uniformity of the corresponding contact regions may be accomplished by an enhanced silicidation process sequence. For this purpose, the Fins may be embedded into a dielectric material in which an appropriate contact opening may be formed to expose end faces of the Fins, which may then act as silicidation surface areas.

Abstract: The present disclosure provides a method for manufacturing a semiconductor field effect transistor, comprising: forming a semiconductor substrate having a local Silicon-on-Insulator (SOI) structure, which comprises a local buried isolation dielectric layer; forming a fin on a silicon substrate above the local buried isolation dielectric layer; forming a gate stack structure on a top and on side faces of the fin; forming source/drain structures in the fin at both sides of the gate stack structure; and metallizing. The present disclosure uses a conventional top-to-bottom process based on quasi-plane, which has a good compatibility with CMOS planar processes. Also, the method can suppress short channel effects and help to reduce the dimensions of MOSFETs.

Abstract: A fabricating method of a transistor is provided. A patterned sacrificed layer is formed on a substrate, wherein the patterned sacrificed layer includes a plurality of openings exposing the substrate. By using the patterned sacrificed layer as a mask, a doping process is performed on the substrate, thereby forming a doped source region and a doped drain region in the substrate exposed by the openings. A selective growth process is performed to form a source and a drain on the doped source region and the doped drain region, respectively. The patterned sacrificed layer is removed to expose the substrate between the source and the drain. A gate is formed on the substrate between the source and the drain.

Abstract: Structures and methods are presented relating to formation of finFET semiconducting devices. A finFET device is presented comprising fin(s) formed on a substrate, wherein the fin(s) has a needle-shaped profile. The needle-shaped profile, in conjunction with at least a buffer layer or a doped layer, epitaxially formed on the fin(s), facilitates strain to be induced into the fin(s) by the buffer layer or the doped layer. The fin(s) can comprise silicon aligned on a first plane, while at least one of the buffer layer or the doped layer are grown on a second plane, the alignment of the first and second planes are disparate and are selected such that formation of the buffer layer or the doped layer generates a stress in the fin(s). The generated stress results in a strain being induced into the fin(s) channel region, which can improve electron and/or hole mobility in the channel.

Abstract: A method of forming a transistor is disclosed, in which gate-to-substrate leakage is addressed by forming and maintaining a conformal oxide layer overlying the transistor gate. Using the method disclosed for an n-type device, the conformal oxide layer can be formed as part of the source-drain doping process. Subsequent removal of residual phosphorous dopants from the surface of the oxide layer is accomplished without significant erosion of the oxide layer. The removal step uses a selective deglazing process that employs a hydrolytic reaction, and an acid-base neutralization reaction that includes an ammonium hydroxide component.

Abstract: A semiconductor device includes a first NMOS device with a first threshold voltage and a second NMOS device with a second threshold voltage. The first NMOS device includes a first gate structure over a semiconductor substrate, first source/drain (S/D) regions in the semiconductor substrate and adjacent to opposite edges of the first gate structure. The first S/D regions are free of dislocation. The second NMOS device includes a second gate structure over the semiconductor substrate, second S/D regions in the semiconductor substrate and adjacent to opposite edges of the second gate structure, and a dislocation in the second S/D regions.

Abstract: The present invention provides a manufacturing method for a semiconductor device having epitaxial source/drain regions, in which a diffusion barrier layer of the source/drain regions made of epitaxial silicon-carbon or germanium silicon-carbon are added on the basis of epitaxially growing germanium-silicon of the source/drain regions in the prior art process, and the introduction of the diffusion barrier layer of the source/drain regions prevents diffusion of the dopant in the source/drain regions, thus mitigating the SCE and DIBL effect.

Abstract: A method of forming a device is disclosed. A substrate having a high gain (HG) device region for a HG transistor is provided. A HG gate is formed on the substrate in the HG device region. The HG gate includes sidewall spacers on its sidewalls. Heavily doped regions are formed adjacent to the HG gate. Inner edges of the heavily doped regions are aligned with about outer edges of the sidewall spacers of the HG gate. The heavily doped regions serve as HG source/drain (S/D) regions of the HG gate. The HG S/D regions do not include lightly doped drain (LDD) regions or halo regions.

Abstract: An S/D region including a first region and a second region is provided. The first region is located, with at least a partial thickness, in the substrate. The second region is formed on the first region and made of a material different from that of the first region. A method for forming an S/D region is further provided, and the method includes: forming trenches at both sides of a gate stack structure in a substrate; forming a first semiconductor layer, wherein at least a part of the first semiconductor layer is filled into the trenches; and forming a second semiconductor layer on the first semiconductor layer, wherein the second semiconductor layer is made of a material different from that of the first semiconductor layer. A contact hole and a forming method thereof are also provided which may increase the contact area between a contact hole and a contact region, and reduce the contact resistance.

Abstract: The present invention includes methods for stressing transistor channels of semiconductor device structures. Such methods include the formation of so-called near-surface “nanocavities” adjacent to the source/drain regions, forming extensions of the source/drain regions adjacent to and including the nanocavities, and implanting matter of a type that will expand or contract the volume of the nanocavities, depending respectively upon whether compressive strain is desirable in transistor channels between the nanocavities, as in PMOS field effect transistors, or tensile strain is wanted in transistor channels, as in NMOS field effect transistors, to enhance carrier mobility and transistor speed. Semiconductor device structures and semiconductor devices including these features are also disclosed.

Abstract: The drain and source regions may at least be partially formed by in situ doped epitaxially grown semiconductor materials for complementary transistors in sophisticated semiconductor devices designed for low power and high performance applications. To this end, cavities may be refilled with in situ doped semiconductor material, which in some illustrative embodiments also provides a desired strain in the channel regions of the complementary transistors.

Abstract: According to one embodiment, a method for manufacturing a semiconductor device includes forming a depression in an upper portion of a semiconductor substrate, placing a sacrificial material in the depression, forming a plurality of fins extending in one direction and arranged periodically by selectively removing the semiconductor substrate and the sacrificial material, forming a device isolation insulating film in a lower portion of space between the fins, removing the sacrificial material, forming a gate insulating film on an exposed surface of the fin, and forming a gate electrode. The gate electrode extends in a direction crossing the one direction so as to straddle the fin on the device isolation insulating film.

Abstract: A method of manufacturing an organic light-emitting display device includes forming a gate electrode including a lower gate electrode on a gate insulating layer and an upper gate electrode on the lower gate electrode; forming a source region and a drain region at a semiconductor active layer using the gate electrode as a mask; forming an interlayer insulating layer on a substrate and etching the interlayer insulating layer, resulting in contact holes that expose portions of the source region and the drain region; forming a source/drain electrode raw material on the substrate and etching the source/drain electrode raw material to form a source electrode and a drain electrode; forming a gold overlapped lightly doped drain (GOLDD) structure having a LDD region at the semiconductor active layer by injecting impurity ions; depositing a protective layer on the substrate; and forming a display device on the substrate.

Abstract: A method of fabricating a semiconductor device can be provided by etching sidewalls of a preliminary trench in a substrate that are between immediately adjacent gate electrode structures, to recess the sidewalls further beneath the gate electrode structures to provide recessed sidewalls. Then, the recessed sidewalls and a bottom of the preliminary trench can be etched using crystallographic anisotropic etching to form a hexagonally shaped trench in the substrate.

Abstract: While embedded silicon germanium alloy and silicon carbon alloy provide many useful applications, especially for enhancing the mobility of MOSFETs through stress engineering, formation of alloyed silicide on these surfaces degrades device performance. The present invention provides structures and methods for providing unalloyed silicide on such silicon alloy surfaces placed on semiconductor substrates. This enables the formation of low resistance contacts for both mobility enhanced PFETs with embedded SiGe and mobility enhanced NFETs with embedded Si:C on the same semiconductor substrate. Furthermore, this invention provides methods for thick epitaxial silicon alloy, especially thick epitaxial Si:C alloy, above the level of the gate dielectric to increase the stress on the channel on the transistor devices.

Abstract: A method includes forming a gate structure over a semiconductor substrate. The gate structure defines a channel region in the semiconductor substrate. Trenches are formed in the semiconductor substrate, and the trenches are interposed by the channel region. A first semiconductor layer is epitaxially grown in the trenches, and the first semiconductor layer has a first dopant with a first dopant concentration. A second semiconductor layer is epitaxially grown over the first semiconductor layer, and the second semiconductor layer has a second dopant with a second dopant concentration. The second dopant has an electrical carrier type opposite to an electrical carrier type of the first dopant.

Abstract: A field effect transistor (FET) has a channel hosted in Ge. The FET has silicon-germanium (SiGe) source and drain formed by selective epitaxy. The SiGe source and drain exert a tensile stress onto the Ge channel. During forming of the SiGe source and drain, an n-type dopant species and a compensating species are being incorporated into the SiGe source and drain. The n-type dopant species and the compensating species are so selected that the size of the SiGe atomic radius is inbetween the dopant atomic radius and the compensating species atomic radius.

Abstract: A method includes forming a gate stack over a semiconductor substrate, wherein the gate stack includes a gate dielectric and a gate electrode over the gate dielectric. A portion of the semiconductor substrate adjacent to the gate stack is recessed to form a recess. A semiconductor region is epitaxially grown in the recess. The semiconductor region is implanted with a p-type impurity or an n-type impurity. A dry treatment is performed on the semiconductor region.

Abstract: Improved silicide formation and associated devices are disclosed. An exemplary method includes providing a semiconductor material having spaced source and drain regions therein, forming a gate structure interposed between the source and drain regions, performing a gate replacement process on the gate structure to form a metal gate electrode therein, forming a hard mask layer over the metal gate electrode, forming silicide layers on the respective source and drain regions in the semiconductor material, removing the hard mask layer to expose the metal gate electrode, and forming source and drain contacts, each source and drain contact being conductively coupled to a respective one of the silicide layers.

Abstract: An integrated circuit device and method for manufacturing the integrated circuit device is disclosed. The disclosed method provides improved control over a surface proximity and tip depth of integrated circuit device. In an embodiment, the method achieves improved control by forming a doped region and a lightly doped source and drain (LDD) region in a source and drain region of the device. The doped region is implanted with a dopant type opposite the LDD region.

Abstract: A method includes forming a gate stack including a gate electrode on a first semiconductor fin. The gate electrode includes a portion over and aligned to a middle portion of the first semiconductor fin. A second semiconductor fin is on a side of the gate electrode, and does not extend to under the gate electrode. The first and the second semiconductor fins are spaced apart from, and parallel to, each other. An end portion of the first semiconductor fin and the second semiconductor fin are etched. An epitaxy is performed to form an epitaxy region, which includes a first portion extending into a first space left by the etched first end portion of the first semiconductor fin, and a second portion extending into a second space left by the etched second semiconductor fin. A first source/drain region is formed in the epitaxy region.

Abstract: A method of forming a transistor device includes forming a patterned gate structure over a semiconductor substrate, forming a raised source region over the semiconductor substrate adjacent a source side of the gate structure, and forming silicide contacts on the raised source region, on the patterned gate structure, and on the semiconductor substrate adjacent a drain side of the gate structure. Thereby, a hybrid field effect transistor (FET) structure having a drain side Schottky contact and a raised source side ohmic contact is defined.

Abstract: The present disclosure provides a semiconductor device having a transistor. The transistor includes a source region, a drain region, and a channel region that are formed in a semiconductor substrate. The channel region is disposed between the source and drain regions. The transistor includes a first gate that is disposed over the channel region. The transistor includes a plurality of second gates that are disposed over the drain region.

Abstract: A method of fabricating a metal silicide layer includes forming a metal layer on a substrate, and forming a pre-metal silicide layer by reacting the substrate with the metal layer by performing a first annealing process on the substrate. The method also includes implanting silicon into the substrate using a gas cluster ion beam (GCIB) process, and changing the pre-metal silicide layer into a metal silicide layer by performing a second annealing process on the substrate.

Abstract: A MOSFET device is formed on top of a semiconductor-on-insulator (SOI) substrate having a semiconductor layer with a thickness ranging from 3 nm to 20 nm. A stair-shape raised extension, a raised source region and a raised drain region (S/D) are formed on top of the SOI substrate. The thinner raised extension region abuts at a thin gate sidewall spacer, lowering the extension resistance without significantly increasing the parasitic resistance. A single epitaxial growth forms the thinner raised extension and the thicker raised S/D preferably simultaneously, reducing the fabrication cost as well as the contact resistance between the raised S/D and the extension. A method of forming the aforementioned MOSFET device is also provided.

Abstract: A voltage converter includes an output circuit having a high side device and a low side device which can be formed on a single die (i.e. a “PowerDie”) and connected to each other through a semiconductor substrate. Both the high side device and the low side device can include lateral diffused metal oxide semiconductor (LDMOS) transistors. Because both output transistors include the same type of transistors, the two devices can be formed simultaneously, thereby reducing the number of photomasks over other voltage converter designs. The voltage converter can further include a controller circuit on a different die which can be electrically coupled to, and co-packaged with, the PowerDie.

Abstract: A method of forming a transistor device includes forming a patterned gate structure over a semiconductor substrate; forming a spacer layer over the semiconductor substrate and patterned gate structure; removing horizontally disposed portions of the spacer layer so as to form a vertical sidewall spacer adjacent the patterned gate structure; and forming a raised source/drain (RSD) structure over the semiconductor substrate and adjacent the vertical sidewall spacer, wherein the RSD structure has a substantially vertical sidewall profile so as to abut the vertical sidewall spacer and produce one of a compressive and a tensile strain on a channel region of the semiconductor substrate below the patterned gate structure.

Abstract: A semiconductor structure includes a semiconductor substrate having a top surface; a gate stack on the semiconductor substrate; and a stressor in the semiconductor substrate and adjacent the gate stack. The stressor comprises at least a first portion with a first top surface lower than the top surface of the semiconductor substrate.

Abstract: A memory device includes a substrate and source and drain regions formed in the substrate. The source and drain regions include both phosphorous and arsenic and the phosphorous may be implanted prior to the arsenic. The memory device also includes a first dielectric layer formed over the substrate and a charge storage element formed over the first dielectric layer. The memory device may further include a second dielectric layer formed over the charge storage element and a control gate formed over the second dielectric layer.

Abstract: A method is provided for fabricating a finFET device. Multiple fin structures are formed over a BOX layer, and a gate stack is formed on the BOX layer. The fin structures each include a semiconductor layer and extend in a first direction, and the gate stack is formed over the fin structures and extends in a second direction. The gate stack includes dielectric and polysilicon layers. Gate spacers are formed on vertical sidewalls of the gate stack, and an epi layer is deposited over the fin structures. Ions are implanted to form source and drain regions, and the gate spacers are etched so that their upper surface is below an upper surface of the gate stack. After etching the gate spacers, silicidation is performed to fully silicide the polysilicon layer of the gate stack and to form silicide regions in an upper surface of the source and drain regions.

Abstract: Embodiments of a method for fabricating an integrated circuit are provided. In one embodiment, the method includes producing a partially-completed semiconductor device including a substrate, source/drain (S/D) regions, a channel region between the S/D regions, and a gate stack over the channel region. At least one raised electrically-conductive structure is formed over at least one of the S/D regions and separated from the gate stack by a lateral gap. The raised electrically-conductive structure is then back-etched to increase the width of the lateral gap and reduce the parasitic fringing capacitance between the raised electrically-conductive structure and the gate stack during operation of the completed semiconductor device.

Abstract: A semiconductor device is disclosed. The semiconductor device includes a semiconductor substrate including a first source drain region, a second source drain region, and an intrinsic region therebetween; an asymmetric lightly doped drain (LDD) region within the substrate, wherein the asymmetric LDD region extends from the first source drain region into the intrinsic region between the first source drain region and the second source drain region; and a gate positioned atop the semiconductor substrate, wherein an outer edge of the gate overlaps the second source drain region. A related method and design structure are also disclosed.

Abstract: An electrostatic discharge protection device, methods of fabricating an electrostatic discharge protection device, and design structures for an electrostatic discharge protection device. A drain of a first field-effect transistor and a diffusion resistor of higher electrical resistance may be formed as different portions of a doped region. The diffusion resistor, which is directly coupled with the drain of the first field-effect transistor, may be defined using an isolation region of dielectric material disposed in the doped region and selective silicide formation. The electrostatic discharge protection device may also include a second field-effect transistor having a drain as a portion the doped region that is directly coupled with the diffusion resistor and indirectly coupled by the diffusion resistor with the drain of the first field-effect transistor.

Abstract: Nonvolatile memory devices having a low off state leakage current and an excellent data retention time characteristics. The present invention provides a surrounding stacked gate fin field effect transistor nonvolatile memory structure comprising a silicon-on-insulator substrate of a first conductivity type and a fin active region projecting from an upper surface of the insulator. The structure further includes a tunnel oxide layer formed on the fin active region and a first gate electrode disposed on the tunnel oxide layer and upper surface of the insulator. Additionally, the structure includes an oxide/nitride/oxide (ONO) composite layer formed on the first gate electrode, a second gate electrode formed on the ONO composite layer and patterned so as to define a predetermined area of the ONO composite layer. The structure further includes a dielectric spacer formed on a sidewall of the second gate electrode and source/drain regions formed in the fin active region on both sides of the second gate electrode.

Abstract: A method of fabricating p-type metal oxide semiconductor (PMOS) transistor devices on a common substrate is presented. The method provides a first portion of semiconductor material and a second portion of semiconductor material on the common substrate. The first portion of semiconductor material and the second portion of semiconductor material are insulated from each other. The method continues by creating first PMOS transistor devices using the first portion of semiconductor material. The first PMOS transistor devices include stressor regions that impart compressive stress to channel regions of the first PMOS transistor devices. The method also creates second PMOS transistor devices using the second portion of semiconductor material. The second PMOS transistor devices do not include channel stressor regions.

Abstract: A method for manufacturing semiconductor devices includes providing a substrate having a first region and a second region defined thereon, and a shallow trench isolation (STI) formed in between the first region and the second region, the first region comprising a first gate structure and the second region comprising a second gate structure respectively formed therein; forming a patterned protecting layer covering at least the entire STI and the second region on the substrate; forming recesses not exposing the STI in the substrate respectively at two sides of the first gate structure; and forming an epitaxial layer in the recesses respectively, the epitaxial layer filling up the recesses.

Abstract: A semiconductor device having dislocations and a method of fabricating the semiconductor device is disclosed. The exemplary semiconductor device and method for fabricating the semiconductor device enhance carrier mobility. The method includes providing a substrate having an isolation feature therein and two gate stacks overlying the substrate, wherein one of the gate stacks is atop the isolation feature. The method further includes performing a pre-amorphous implantation process on the substrate. The method further includes forming spacers adjoining sidewalls of the gate stacks, wherein at least one of the spacers extends beyond an edge the isolation feature. The method further includes forming a stress film over the substrate. The method also includes performing an annealing process on the substrate and the stress film.

Abstract: A memory device includes an array of memory cells and peripheral devices. At least some of the individual memory cells include carbonated portions that contain SiC. At least some of the peripheral devices do not include any carbonated portions. A transistor includes a first source/drain, a second source/drain, a channel including a carbonated portion of a semiconductive substrate that contains SiC between the first and second sources/drains and a gate operationally associated with opposing sides of the channel.

Abstract: A process for forming an integrated circuit with reduced sidewall spacers to enable improved silicide formation between minimum spaced transistor gates. A process for forming an integrated circuit with reduced sidewall spacers by first forming sidewall spacer by etching a sidewall dielectric and stopping on an etch stop layer, implanting source and drain dopants self aligned to the sidewall spacers, followed by removing a portion of the sidewall dielectric and removing the etch stop layer self aligned to the reduced sidewall spacers prior to forming silicide.

Abstract: Disclosed herein are various methods and structures using contacts to create differential stresses on devices in an integrated circuit (IC) chip. An IC chip is disclosed having a p-type field effect transistor (PFET) and an n-type field effect transistor (NFET), a PFET contact to a source/drain region of the PFET and an NFET contact to a source/drain region of the NFET. In a first embodiment, a silicon germanium (SiGe) layer is included only under the PFET contact, between the PFET contact and the source/drain region of the PFET. In a second embodiment, either the PFET contact extends into the source/drain region of the PFET or the NFET contact extends into the source/drain region of the NFET.

Abstract: A semiconductor device having a substrate including a major surface, a gate stack comprising a sidewall over the substrate and a spacer over the substrate adjoining the sidewall of the gate stack. The spacer having a bottom surface having an outer point that is the point on the bottom surface farthest from the gate stack. An isolation structure in the substrate on one side of the gate stack has an outer edge closest to the spacer. A strained material below the major surface of the substrate disposed between the spacer and the isolation structure having an upper portion and a lower portion separated by a transition plane at an acute angle to the major surface of the substrate.

Abstract: A method to form a LDMOS transistor includes forming a gate/source/body opening and a drain opening in a field oxide on a substrate structure, forming a gate oxide in the gate/source/body opening, and forming a polysilicon layer over the substrate structure. The polysilicon layer is anisotropically etched to form polysilicon spacer gates separated by a space in the gate/source/body opening and a polysilicon drain contact in the drain opening. A body region is formed self-aligned about outer edges of the polysilicon spacer gates, a source region is formed self-aligned about inner edges of the polysilicon spacer gates, and a drain region is formed under the polysilicon drain contact and self-aligned with respect to the polysilicon spacer gates. A drift region forms in the substrate structure between the body region and the drain region, and a channel region forms in the body region between the source region and the drift region.

Abstract: A method of manufacturing a semiconductor device, the method including providing a substrate, the substrate including single crystalline silicon and having the first region and a second region; growing a pillar from a top surface of the substrate in the first region; forming a vertical channel transistor including a first gate structure such that first gate structure surrounds a central portion of the pillar; and forming a second transistor on the second region of the substrate such that the second transistor includes a second gate structure.

Abstract: A process of forming a CMOS integrated circuit including integrating SiGe source/drains in the PMOS transistor after source/drain and LDD implants and anneals. A dual layer hard mask is formed on a polysilicon gate layer. The bottom layer prevents SiGe growth on the polysilicon gate. The top layer protects the bottom layer during source/drain spacer removal. A stress memorization layer may be formed on the integrated circuit prior to a source/drain anneal and removed prior to forming a SiGe blocking layer over the NMOS. SiGe spacers may be formed on the PMOS gate to laterally offset the SiGe recesses.

Abstract: Transistor devices and methods of their fabrication are disclosed. In one method, a dummy gate structure is formed on a substrate. Bottom portions of the dummy gate structure are undercut. In addition, stair-shaped, raised source and drain regions are formed on the substrate and within at least one undercut formed by the undercutting. The dummy gate structure is removed and a replacement gate is formed on the substrate.