Abstract: A method of forming a fin field effect transistor includes forming a fin and forming a source region adjacent a first end of the fin and a drain region adjacent a second end of the fin. The method further includes forming a dummy gate over the fin and forming a dielectric layer around the dummy gate. The method also includes removing the dummy gate to form a trench in the dielectric layer and forming a metal gate in the trench.

Abstract: A method for forming dual gate electrodes using a damascene gate process is disclosed.

Abstract: Technique and structures for camouflaging an integrated circuit structure. The integrated circuit structure is formed by a plurality of layers of material having controlled outlines and controlled thicknesses. A layer of dielectric material of a controlled thickness is disposed among said plurality of layers to thereby render the integrated circuit structure intentionally inoperable.

Abstract: A technique for and structures for camouflaging an integrated circuit structure. A layer of conductive material having a controlled outline is disposed to provide artifact edges of the conductive material that resemble an operable device when in fact the device is not operable.

Abstract: A structure includes a substrate, first and second signal lines above the substrate, where unused substrate surface area exists between the first and second signal lines, and a first shield line in the unused substrate surface area. To define the first shield line, the signal line layout which includes the first and second signal lines is defined. Any areas which are not signal lines are then defined as unused areas of the substrate. The shield lines including the first shield line are then defined in portions of the unused areas of the substrate. In this manner, shield lines are automatically designed at every available location without requiring any allocation of substrate surface area.

Abstract: Strained silicon is grown on a dielectric material in a trench in a silicon germanium layer at a channel region of a MOSFET after fabrication of other MOSFET elements using a removable dummy gate process to form an SOI MOSFET. The MOSFET is fabricated with the dummy gate in place, the dummy gate is removed, and a trench is formed in the channel region. Dielectric material is grown in the trench, and strained silicon is then grown from the silicon germanium trench sidewalls to form a strained silicon layer that extends across the dielectric material. The silicon germanium sidewalls impart strain to the strained silicon, and the presence of the dielectric material allows the strained silicon to be grown as a thin fully depleted layer. A replacement gate is then formed by damascene processing.

Abstract: The manufacturing method of the invention is applied to production of a semiconductor device including a memory area and a logic circuit area. The method first provides a semiconductor substrate, which has an element separating region formed on surface of a semiconductor layer to attain insulation between semiconductor elements, a first conductive layer formed above the semiconductor layer and patterned to give a word gate of the non-volatile memory device, a stopper layer formed above the first conductive layer, and control gates formed as side walls via an ONO membrane on both side faces of the first conductive layer in the memory area. The method subsequently patterns the first conductive layer in the logic circuit area to create a gate electrode of an insulated gate field effect transistor, which constructs the peripheral circuit, in the logic circuit area and to create a dummy gate electrode above the element separating region in the logic circuit area.

Abstract: A method is provided for manufacturing a semiconductor device with a highly controlled impurity layer without influence from the heat treatment involved in epitaxial growth. The method comprises: forming a dummy gate layer above a semiconductor substrate; forming a spacer layer closely adjacent to each side of the dummy gate layer; selectively forming a silicon layer by epitaxial growth above the semiconductor substrate; forming a gate electrode after removing the dummy gate layer; forming a source/drain region by introducing an impurity into the semiconductor substrate through the silicon layer; and changing the silicon layer into silicide.

Abstract: A method of forming a nanowire is disclosed. A nanowire having a first dimension is deposited on a first dielectric layer that is formed on a substrate. A sacrificial gate stack having a sacrificial dielectric layer and a sacrificial gate electrode layer is deposited over a first region of the nanowire leaving exposed a second region and a third region of the nanowire. A first spacer is deposited on each side of the sacrificial gate stack. A second dielectric layer is deposited over the first dielectric layer to cover the second region and third region. The sacrificial gate stack is removed. The first region of the nanowire is thinned by at least one thermal oxidation process and oxide removal process to thin said first region from said first dimension to a second dimension.

Abstract: A method for forming a semiconductor structure removes the temporary gate formed on the dielectric layer to expose a recess in which oxygen-rich CVD oxide is deposited. A tantalum layer is then deposited by low-power physical vapor deposition on the CVD oxide. Annealing is then performed to create a Ta2O5 region and a Ta region from the deposited oxide and Ta. This creates a low carbon-content Ta2O5 and a metallic Ta gate in a single process step.

Abstract: A method is provided for eliminating uneven heating of substrate active areas during laser thermal annealing (LTA) due to variations in gate electrode density. Embodiments include adding dummy structures, formed simultaneously with the gate electrodes, to “fill in” the spaces between isolated gate electrodes, such that the spacing between the gate electrodes and the dummy structures is the same as the spacing between the densest array of device structures on the substrate surface. Since the surface features (i.e., the gate electrodes and the dummy structures) appear substantially uniform to the LTA laser, the laser radiation is uniformly absorbed by the substrate, and the substrate surface is evenly heated.

Abstract: The invention includes a field effect transistor (FET) on an insulator layer, and integrated circuit (IC) on SOI chip including the FETs and a method of forming the IC. The FETs include a thin channel with raised source/drain (RSD) regions at each end on an insulator layer, e.g., on an ultra-thin silicon on insulator (SOI) chip. Isolation trenches at each end of the FETs, i.e., at the end of the RSD regions, isolate and define FET islands. Insulating sidewalls at each RSD region sandwich the FET gate between the RSD regions. The gate dielectric may be a high K dielectric. Salicide on the RSD regions and, optionally, on the gates reduce device resistances.

Abstract: A sub-0.05 ?m channel length fully-depleted SOI MOSFET device having low source and drain resistance and minimal overlap capacitance and a method of fabricating the same are provided. The sub-0.05 ?m channel length fully-depleted SOI MOSFET device includes an SOI structure which contains at least an SOI layer having a channel region of a first thickness and abutting source/drain regions of a second thickness present therein, wherein the second thickness is greater than the first thickness and the source/drain regions having a salicide layer present thereon. A gate region is present also atop the SOI layer.

Abstract: The present invention discloses semiconductor device which comprises a metal gate electrode surrounded by polysilicon layers and a gate insulating film whose edges are thicker than the center portion formed according to a reoxidation process using a thermal process before the formation of an ion implantation region in a process for forming the metal gate electrode using a replacement process and method for manufacturing the same.

Abstract: A method of forming a double gated SOI channel transistor comprising the following steps. A substrate having an SOI structure formed thereover is provided. The SOI structure including a lower SOI silicon oxide layer and an upper SOI silicon layer. The SOI silicon layer is patterned to form a patterned silicon layer. A dummy layer is formed over the SOI silicon oxide layer and the patterned SOI silicon layer. The dummy layer is patterned to form a damascene opening therein exposing: a portion of the lower SOI silicon oxide layer; and a central portion of the patterned SOI silicon layer to define a source structure and a drain structure. Patterning the exposed lower SOI silicon oxide layer to form a recess. Gate oxide layer portions are formed around the exposed portion of the patterned SOI silicon layer. A planarized layer portion is formed within the final damascene opening. The planarized layer portion including a bottom gate and a top gate.

Abstract: A method of manufacturing a semiconductor device comprising the steps of forming a dummy film and a dummy gate pattern at a predetermined gate-forming region on a semiconductor substrate, forming a first side wall insulating film on a side wall of the dummy gate pattern, forming an interlayer insulating film on a portion of the semiconductor substrate around the dummy gate pattern bearing the first side wall insulating film, forming a groove by removing the dummy gate pattern, removing a portion of dummy film exposed through the groove while leaving a portion of the first side wall insulating film as well as a portion of the dummy film disposed below the portion of the first side wall insulating film, forming a gate insulating film at least on a bottom surface of the groove, and forming a gate electrode on the gate insulating film formed in the groove.

Abstract: A MOS transistor with a drain extension includes an isolation block on the upper surface of a semiconductor substrate. The isolation block has a first sidewall next to the gate of the transistor, and a second sidewall that is substantially parallel to the first sidewall. The isolation block further includes a drain extension zone in the substrate under the isolation block, and a drain region in contact with the drain extension zone. The drain region is in the substrate but is not covered by the isolation block.

Abstract: An MOS device comprising a gate dielectric formed on a first conductivity type region. A gate electrode formed on the gate dielectric. A pair of sidewall spacers are formed along laterally opposite sidewalls of the gate electrode. A pair of deposited silicon or silicon alloy source/drain regions are formed in the first conductivity region and on opposite sides of a gate electrode wherein the silicon or silicon alloy source/drain regions extend beneath the gate electrode and to define a channel region beneath the gate electrode in the first conductivity type region wherein the channel region directly beneath the gate electrode is larger than the channel region deeper into said first conductivity type region.

Abstract: A method for forming an electrical insulating layer on bit lines of the flash memory is disclosed. A conductive layer, a mask layer and a cap layer are sequentially formed on a semiconductor substrate and then are etched to form a plurality of spacing. Afterwards, a dielectric layer is formed on the semiconductor substrate and a planarized layer is then formed on the dielectric layer. The planarized layer and the dielectric layer are etched sequentially wherein the etching rate of the planarized layer is less than that of the dielectric layer. Next, the dielectric layer is etched to remove a portion of the dielectric layer wherein the etching rate of the dielectric layer is higher than that of the cap layer, and thus a spacing dielectric layer is formed on the spacing. Thereafter, the cap layer is stripped wherein the etching rate of the dielectric layer is less than that of the mask layer so that the spacing dielectric layer has a round top and slant sides.

Abstract: An integrated circuit employing CMOS technology employs a process integration that combines a source/drain silicide with a replacement gate process using a triple layer hardmask that is consumed during the course of processing in which a first temporary gate sidewall spacer defines an area for the formation of the raised source and drain and a second temporary spacer defines an area for the implant of the source and drain and for the siliciding of the source and drain while the temporary gate is protected from silicidaiton by the hardmask.

Abstract: A method is provided for manufacturing a semiconductor device with a highly controlled impurity layer without influence from the heat treatment involved in epitaxial growth. The method comprises: forming a dummy gate layer above a semiconductor substrate; forming a spacer layer closely adjacent to each side of the dummy gate layer; selectively forming a silicon layer by epitaxial growth above the semiconductor substrate; forming a gate electrode after removing the dummy gate layer; forming a source/drain region by introducing an impurity into the semiconductor substrate through the silicon layer; and changing the silicon layer into silicide.

Abstract: A method of manufacturing an integrated circuit utilizes solid phase epitaxy to form an elevated source region and an elevated drain region. The method includes providing a mask structure including spacers, removing the mask structure, providing an amorphous semiconductor material and crystallizing the amorphous semiconductor material without damaging a high-k gate dielectric layer. The semiconductor material can be silicided. A shallow source/drain implant can also be provided.

Abstract: A gate structure which includes a semiconductor substrate having a channel region, a gate insulator adjacent the channel region of the semiconductor substrate and a conductible gate adjacent the gate insulator. A primary insulation layer is adjacent the semiconductor substrate, the primary insulation layer having an opening where the gate insulator contacts the semiconductor substrate and an isolation dielectric layer adjacent the primary insulation layer, the isolation dielectric layer having an opening where the conductible gate is located and the isolation dielectric layer having a silicon oxynitride material.

Abstract: A process for fabricating a CMOS device in which conductive gate structures are defined self-aligned to shallow trench isolation (STI), regions, without using a photolithographic procedure, has been developed. The process features definition of shallow trench openings in regions of a semiconductor substrate not covered by dummy gate structures, or by silicon oxide spacers located on sides of the dummy gate structures. Filling of the shallow trench openings with silicon oxide, and removal of the dummy gate structures, result in STI regions comprised of filled shallow trench openings, overlying silicon oxide shapes, and silicon oxide sidewall spacers on the sides of the overlying silicon oxide shapes. Formation of silicon nitride spacers on the sides of the STI regions, is followed by deposition of a high k gate insulator layer and of a conductive gate structure, with the conductive gate structure formed self-aligned to the STI regions.

Abstract: A method of forming a specialized channel region removes a sacrificial gate material and provides a semiconductor implant though the recess associated with the remove sacrificial gate material. The process can be utilized to form a silicon germanium layer in the channel region having a sharp profile in the vertical direction. Further, the silicon germanium layer can be ultra-thin. The silicon germanium channel region has increased charge mobility with respect to conventional channel regions.

Abstract: An etch stopper member is formed under a cell plate electrode so as to surround an active region along a periphery of the cell plate electrode. The etch stopper member is formed from a material that is resistant to an etchant of a first interlayer insulating film. For example, a dummy gate line and a cylindrical wall formed thereon are provided as the etch stopper member. Either the dummy gate line or the cylindrical wall may be provided as the etch stopper member. The etch stopper member prevents the interlayer insulating film from being laterally etched at the boundary between a DRAM memory section and a logic section. This eliminates the need to provide an etching margin, allowing for reduction in the area of the DRAM memory section.

Abstract: The present invention provides a MISFET with a replacement gate electrode, which ensures large ON-current. A semiconductor device, in which on the substrate, first and second field effect transistors are formed, the first field effect transistor is a replacement gate type field effect transistor, and the length of the overlap between a gate electrode and a source/drain diffusion zone of the first field effect transistor correspond to that between a gate electrode and a source/drain diffusion zone of the second field effect transistor.

Abstract: A method for forming a junction electrode of a semiconductor device where a gate is formed on a semiconductor substrate by using a predetermined device structure, a contact hole is formed by stacking an interlayer insulation film on the gate, and n-type and p-type junction electrodes are formed in the contact hole according to an epitaxial growth method, thereby preventing a defect due to the implantation and improving yields of the semiconductor devices. Moreover, a selective silicon growth method may be employed in a narrow junction portion, thereby reducing the number of processes, prime cost, and time. In addition, performance of the electrode is exemplary and homogeneous, a result which has not been achieved using conventional implantation methods.

Abstract: Interconnections are formed over an interlayer insulating film which covers MISFETQ1 formed on the principal surface of a semiconductor substrate, while dummy interconnections are disposed in a region spaced from such interconnections. Dummy interconnections are disposed also in a scribing area. Dummy interconnections are not formed at the peripheries of a bonding pad and a marker. In addition, a gate electrode of a MISFET and a dummy gate interconnection formed of the same layer are disposed. Furthermore, dummy regions are disposed in a shallow trench element isolation region. After such dummy members are disposed, an insulating film is planarized by the CMP method.

Abstract: The present invention includes methods and structures for forming at least a substantially self-aligned MOSFET. According to the present invention, a method of fabricating a semiconductor device includes providing a substrate; providing first materials (such as a first polysilicon) having horizontal surfaces and also having opposed vertical surfaces forming a trench; providing a second material (such as a second polysilicon) in the trench and over the vertical and horizontal surfaces, the second material having a substantially (eg, ±10%) uniform thickness so as to form a notch over the trench; providing a masking material (such as an oxide or a nitride) into the notch, and then removing the second material using the masking material as a mask in a direction toward the first material, so that a vertical surface of one of the first materials is at least substantially aligned with a vertical surface of the second material.

Abstract: A semiconductor device includes a gate insulating film formed on a semiconductor substrate between first diffusion layers, a gate electrode including a first gate portion formed on the gate insulating film and a second gate portion formed on the first gate portion, a first width in a channel direction of the first gate portion being substantially equal to a width in that of the gate insulating film, and a second width in the channel direction of the second gate portion being larger than the first width, a gate side wall insulating film including a first side wall portion formed on a side surface of the first gate portion and the gate insulating film and a second side wall portion formed on a side surface of the second gate portion, and a second diffusion layer formed apart from the first diffusion layers below the gate insulating film.

Abstract: A semiconductor device including an IGFET (insulated gate field effect transistor) (30) is disclosed. IGFET (30) may include a source/drain area (15) having an impurity concentration distribution that may be formed shallower at a higher concentration than the impurity concentration distribution in another source/drain area (7). A gate oxide film may include a first gate oxide film (5) adjacent to source/drain area (7) and a second gate oxide film (12) adjacent to source drain area (15). Second gate oxide film (12) may be thinner than first gate oxide film (5). An impurity concentration distribution of a second channel impurity area (11) under second gate oxide film (12) may be at a higher concentration than an impurity concentration distribution of a first channel impurity area (9) under first gate oxide film (5). In this way, an electric field at a PN junction of source/drain area (7) may be reduced.

Abstract: Disclosed herein is a method of fabricating a semiconductor device using a damascene process. The method comprises the steps of: forming a dummy gate electrode on a semiconductor substrate; forming a source/drain region in the substrate; polishing and planarizing an interlayer insulating film formed on the substrate to expose the dummy gate electrode; etching the dummy gate electrode to form a groove in an exposed portion of the substrate; implanting impurity ions into the exposed portion of the substrate to form a delta-doping layer; thermally treating the semiconductor substrate to activate the implanted impurity ions; growing a silicon film on the exposed portion of the substrate by a selective epitaxial process; depositing a gate insulating film on the surface of the groove; and depositing a gate metal film on the gate insulating film in the groove, forming the gate electrode.

Abstract: An integrated circuit metal oxide semiconductor device comprises a gate region and a dielectric layer positioned therein, wherein the dielectric layer is substantially free of germanium diffused therein from a silicon germanium layer of the device. The method comprises depositing a dummy replacement gate, subjecting the device to high temperature processing, removing the dummy gate, and then depositing a dielectric material and a final gate material within the formed gate region. Because the dielectric material is deposited after high temperature processing of the device, there is negligible diffusion of germanium into the dielectric material.

Abstract: A method of fabricating an RF lateral MOS device, comprising the following steps. A substrate having a gate oxide layer formed thereover is provided. A first layer of polysilicon is formed over the gate oxide layer. A second layer of material is formed over the polysilicon layer. The polysilicon and the second layer of material are patterned to form a gate having exposed sidewalls with the gate having a lower patterned polysilicon layer and an upper patterned second material layer. Sidewall spacers are formed on the exposed sidewalls of the gate. The upper patterned second material layer of the gate is removed to form a cavity above the patterned polysilicon layer and between the sidewall spacers. A planarized copper plug is formed within the cavity.

Abstract: Disclosed is an ISFET comprising a H+-sensing membrane consisting of RF-sputtering a-WO3. The a-WO3/SiO2-gate ISFET of the present invention is very sensitive in aqueous solution, and particularly in acidic aqueous solution. The sensitivity of the present ISFET ranges from 50 to 58 mV/pH. In addition, the disclosed ISFET has high linearity. Accordingly, the disclosed ISFET can be used to detect effluent.

Abstract: A semiconductor device and a method for fabricating the semiconductor device using a damascene process are disclosed. The method includes forming an Al2O3 film over a dummy gate disposed over a semiconductor substrate. Next, the dummy gate and a portion of the Al2O3 film are removed to form a groove defined by remains of the Al2O3 film and the semiconductor substrate. Then, a subsequent film is deposited within the groove, and a gate material is formed over the second film to complete the semiconductor device.

Abstract: Self-aligned contacts in integrated circuits can be formed on an integrated circuit substrate having an active region. A groove can be formed in the insulating layer and a conductive material can be formed in the groove to a level that is recessed in the groove. An insulating material can be formed in the groove on the conductive material that has an etch selectivity with respect to the insulating layer. A contact that is self-aligned to the active region can be then be formed.

Abstract: A metal gate MISFET comprises a metal gate electrode on a semiconductor substrate, a side wall insulation film, and a source-drain region which is formed on the surface of the semiconductor substrate on both sides of the side wall insulation film. Then, a cobalt silicide film is formed on the source-drain region. In this step of manufacturing the MISFET, since the cobalt silicide film is sealed with the silicon nitride film at the time of oxidizing the surface of the substrate of a gate portion, the property of the cobalt silicide film will never be deteriorated. As a consequence, the metal-gate field effect transistor having a low parasitic resistance of the source-drain region can be obtained.

Abstract: The semiconductor device comprises: a conducting layer including: a channel region; a source region and a drain region sandwiching the channel region; and a body region connected to the channel region and being adjacent to the source region and the drain region; a gate electrode formed above the channel region interposing a gate insulation film therebetween; a dummy electrode formed on the body region near the interface between at least the drain region and the body region, and electrically insulated with the gate electrode; and a body contact region formed in the body region except a region where the dummy electrode is formed. The gate electrode and the dummy electrode are electrically insulated with each other, whereby the semiconductor device having body contacts can have a gate capacitance much decreased. Accordingly, deterioration of the speed performance of the transistors can be suppressed.

Abstract: A method of forming dual-metal gates in a semiconductor device, including the steps of providing a semiconductor substrate having a PMOS area and an NMOS area wherein dummy gates are formed in the PMOS and NMOS areas respectively, forming an insulating interlayer on the semiconductor substrate so as to cover the dummy gates, polishing the insulating interlayer until the dummy gates are exposed, forming a first groove defining a first metal gate area by selectively removing one of the dummy gates formed in the PMOS and NMOS areas, forming a first gate insulating layer and a first metal layer on an entire area of the semiconductor substrate including the first groove successively, forming a first metal gate in the first groove by etching the first metal layer and first gate insulating layer until the insulating interlayer is exposed, forming a second groove defining a second metal gate area by removing the remaining dummy gate, forming a second gate insulating layer and a second metal layer on the entire area o

Abstract: A technology of preventing the threshold voltage of the transistor of a cell region from increasing and the refresh characteristic of the transistor of the cell region from deteriorating, while maintaining the characteristic of the transistor of core circuit/peripheral circuit regions of a semiconductor memory device, is provided. A semiconductor memory device comprises a first transistor comprised of a first gate, a first gate insulating film, a first source region, and a first drain region formed in core circuit/peripheral circuit regions of a semiconductor memory device having a cell region and core circuit/peripheral circuit regions, a planarized interlayer dielectric film which covers the first transistor, and a second transistor formed in the cell region, including a second source region, a second drain region, a second gate having a height corresponding to the height of the interlayer dielectric film, and a second gate insulating film.

Abstract: To achieve a lower operating gate voltage for an FET, while avoiding breakdown and similar problems, a high K dielectric such as aluminum or zirconium oxide can be used As deposited, these materials tend to have a high density of trapped charge. The present invention discloses how such charge may be neutralized by impregnating the high K dielectric layer with between about 5 and 10 atomic percent of nitrogen. Several methods for introducing the nitrogen are described. These include diffusion from an overlay of silicon nitride, diffusion from a gas source, remote plasma nitridation, and decoupled plasma nitridation.

Abstract: An ultra-thin body SOI MOSFET transistor and fabrication method are described which provide extended silicide depth in a gate-last process. The method utilizes the fabrication of a dummy gate, comprising insulation, which is replaced with an insulated gate after implantation, annealing, and the formation of silicide so that diffusion effects are reduced. By way of example, dummy gate stacks are created having insulating upper segments. Silicon is deposited on the wafer and planarized to expose the insulating segment. The junction is formed by implantation followed by annealing to recrystallize the silicon and to activate the junction. Silicide is then formed, to a depth which can exceed the thickness of the silicon within the SOI wafer, on the upper portion of the silicon layer. The segment of insulation is then removed and a gate is formed with a gate electrode insulated by high-k dielectric.

Abstract: A method for adjusting Vt while minimizing parasitic capacitance for low voltage high speed semiconductor devices. The method uses shadow effects and an angled punch through prevention implant between vertical structures to provide a graded implant. The implant angle is greater than or equal to arc tangent of S/H where S is the horizontal distance between, and H is the height of, such vertical structures.

Abstract: A metal gate MISFET comprises a metal gate electrode on a semiconductor substrate, a side wall insulation film, and a source-drain region which is formed on the surface of the semiconductor substrate on both sides of the side wall insulation film. Then, a cobalt silicide film is formed on the source-drain region. In this step of manufacturing the MISFET, since the cobalt silicide film is sealed with the silicon nitride film at the time of oxidizing the surface of the substrate of a gate portion, the property of the cobalt silicide film will never be deteriorated. As a consequence, the metal-gate field effect transistor having a low parasitic resistance of the source-drain region can be obtained.

Abstract: A method for forming insulating spacers for separating conducting layers in semiconductor wafer fabrication. The spacers are formed by removing portions of a protective photoresist layer through photolithography, and then through etching of exposed portions of the insulating layer. The spacers allow for fabrication of components that are smaller in size than are obtainable through conventional photolithography methods.

Abstract: Interband tunnel diodes which are compatible with Si-based processes such as, but not limited to, CMOS and SiGe HBT fabrication. Interband tunnel diodes are disclosed (i) with spacer layers surrounding a tunnel barrier; (ii) with a quantum well adjacent to, but not necessarily in contact with, one of the injectors, and (iii) with a first quantum well adjacent to, but not necessarily in contact with, the bottom injector and a second quantum well adjacent to, but not necessarily in contact with, the top injector. Process parameters include temperature process for growth, deposition or conversion of the tunnel diode and subsequent thermal cycling which to improve device benchmarks such as peak current density and the peak-to-valley current ratio.

Abstract: Methods for forming notched gates and semiconductor devices utilizing the notched gates are provided. The methods utilize the formation of a dummy gate on a substrate. The dummy gate is etched to form notches in the dummy gate, and sidewall spacers are formed on the sidewalls of the notched dummy gate. The dummy gate is removed, and a notched gate is formed. The methods allow the height and depth of the notches to be independently controlled, and transistors having shorter channel lengths are formed.

Abstract: A gate insulating film is provided on a channel region. A gate electrode includes a lower part and an upper part. The lower part has a lower surface and sides, and the upper part has a lower surface. The lower surface of the lower part contacts the gate insulating film. The upper part is longer than the lower part in a lengthwise direction of a gate electrode. The first insulating film is interposed between the lower surface of the upper part of the gate electrode and a semiconductor substrate. The first insulating film surrounds at least the sides of the lower part of the gate electrode, which face drain and source regions, and having parts interposed between the lower surface of the upper part of the gate electrode and the semiconductor substrate and made thicker than the other parts.