Abstract: Provided is a method for manufacturing a MOS transistor.

Abstract: A process for manufacturing a thin-film transistor device includes forming a dielectric insulation layer on a substrate, forming an amorphous silicon layer on the dielectric insulation layer, crystallizing the amorphous silicon layer, so as to obtain polycrystalline silicon, forming gate structures on the polycrystalline silicon, and forming first doped regions within the polycrystalline silicon laterally with respect to the gate structures. The crystallizing step includes forming first capping dielectric regions on the amorphous silicon layer, and then irradiating the amorphous silicon layer using a laser so as to form active areas of polycrystalline silicon separated by separation portions of amorphous silicon underlying the first capping dielectric regions.

Abstract: The present invention relates to methods for fabricating nanoscale electrodes separated by a nanogap, wherein the gap size may be controlled with high precision using a self-aligning aluminum oxide mask, such that the gap width depends upon the thickness of the aluminum oxide mask. The invention also provides methods for using the nanoscale electrodes.

Abstract: An embodiment of a method for forming silicide areas of different thicknesses in a device comprising first and second silicon areas, comprising the steps of: implanting antimony or aluminum in the upper portion of the first silicon areas; covering the silicon areas with a metallic material; and heating the device to transform all or part of the silicon areas into silicide areas, whereby the silicide areas formed at the level of the first silicon areas are thinner than the silicide areas formed at the level of the second silicon areas.

Abstract: Equivalent oxide thickness (EOT) scaled high k/metal gate stacks are provided in which the capacitance bottleneck of the interfacial layer is substantially eliminated, with minimal compromise on the mobility of carriers in the channel of the device. In one embodiment, the aforementioned EOT scaled high k/metal gate stacks are achieved by increasing the dielectric constant of the interfacial layer to a value that is greater than the originally formed interfacial layer, i.e., the interfacial layer prior to diffusion of a high k material dopant element therein. In another embodiment, the aforementioned scaled high k/metal gate stacks are achieved by eliminating the interfacial layer from the structure. In yet another embodiment, the aforementioned high k/metal gate stacks are achieved by both increasing the dielectric constant of the interfacial layer and reducing/eliminating the interfacial layer.

Abstract: A method of producing a semiconducting device is provided that in one embodiment includes providing a semiconducting device including a gate structure atop a substrate, the gate structure including a dual gate conductor including an upper gate conductor and a lower gate conductor, wherein at least the lower gate conductor includes a silicon containing material; removing the upper gate conductor selective to the lower gate conductor; depositing a metal on at least the lower gate conductor; and producing a silicide from the metal and the lower gate conductor. In another embodiment, the inventive method includes a metal as the lower gate conductor.

Abstract: A method of forming (and apparatus for forming) tantalum silicide layers (including tantalum silicon nitride layers), which are typically useful as diffusion barrier layers, on a substrate by using a vapor deposition process with a tantalum halide precursor compound, a silicon precursor compound, and an optional nitrogen precursor compound.

Abstract: A method of setting a work function of a fully silicided semiconductor device, and related device. At least some of the illustrative embodiments are methods comprising forming a gate stack over a semiconductor substrate (the gate stack comprising a dielectric layer, a silicide layer on the dielectric layer that defines a metal-dielectric layer interface, and a polysilicon layer on the silicide layer), depositing a metal layer over the gate stack, annealing to induce a reaction between the polysilicon layer and the metal layer, and delivering a work function-setting dopant to the metal-dielectric layer interface by way of the reaction.

Abstract: The present disclosure provides a method of fabricating a semiconductor device that includes providing a semiconductor substrate, forming a metal gate on the substrate, the metal gate having a first gate resistance, removing a portion of the metal gate thereby forming a trench; and forming a conductive structure within the trench such that a second gate resistance of the conductive structure and remaining portion of the metal gate is lower than the first gate resistance.

Abstract: The invention provides a technique to manufacture a highly reliable semiconductor device and a display device at high yield. As an exposure mask, an exposure mask provided with a diffraction grating pattern or an auxiliary pattern formed of a semi-transmissive film with a light intensity reducing function is used. With such an exposure mask, various light exposures can be more accurately controlled, which enables a resist to be processed into a more accurate shape. Therefore, when such a mask layer is used, the conductive film and the insulating film can be processed in the same step into different shapes in accordance with desired performances. As a result, thin film transistors with different characteristics, wires in different sizes and shapes, and the like can be manufactured without increasing the number of steps.

Abstract: A transistor disposed on a substrate includes a gate, spacers on gate sidewalls, and diffusion regions adjacent to the gate. Silicide contacts on the diffusion regions are displaced from the spacers by a distance G. Stressors may be provided in the diffusion region to induce a first stress in the channel region of the transistor.

Abstract: The present invention relates to a thin-film resistor for an attenuator that is utilized in the fourth generation mobile communication, and more specifically, to a thin-film resistor having a Ti(N) thin film formed on an aluminum nitride (ALN) substrate. The thin-film resistor of the invention has superior electrical characteristics, such as sheet resistance, and superior characteristics in change of attenuation and voltage standing wave ratio (VSWR) with respect to changes of frequency and L/W, and thus the thin-film resistor can be utilized in a high frequency domain of up to 6 GHz.

Abstract: Some embodiments include methods of forming charge storage transistor gates and standard FET gates in which common processing is utilized for fabrication of at least some portions of the different types of gates. FET and charge storage transistor gate stacks may be formed. The gate stacks may each include a gate material, an insulative material, and a sacrificial material. The sacrificial material is removed from the FET and charge storage transistor gate stacks. The insulative material of the FET gate stacks is etched through. A conductive material is formed over the FET gate stacks and over the charge storage transistor gate stacks. The conductive material physically contacts the gate material of the FET gate stacks, and is separated from the gate material of the charge storage transistor gate stacks by the insulative material remaining in the charge storage transistor gate stacks. Some embodiments include gate structures.

Abstract: A MOS transistor having its gate successively comprising an insulating layer, a metal silicide layer, a layer of a conductive encapsulation material, and a polysilicon layer.

Abstract: A structure and method to create a metal gate having reduced threshold voltage roll-off. A method includes: forming a gate dielectric material on a substrate; forming a gate electrode material on the gate dielectric material; and altering a first portion of the gate electrode material. The altering causes the first portion of the gate electrode material to have a first work function that is different than a second work function associated with a second portion of the gate electrode material.

Abstract: A semiconductor device and a manufacturing method thereof that can prevent mutual diffusion of impurity in a silicide layer and can decrease sheet resistance of an N-type polymetal gate electrode and a P-type polymetal gate electrode, respectively in the semiconductor device having gate electrodes of a polymetal gate structure and a dual gate structure are provided. The P-type polymetal gate electrode includes a P-type silicon layer containing P-type impurity, a silicide layer formed on the P-type silicon layer and having a plurality of silicide grains which are discontinuously disposed in a direction substantially parallel with the surface of the semiconductor substrate, a silicon film continuously formed on the surface of the P-type silicon layer exposed on the discontinuous part of the silicide layer and on the surface of the silicide layer, a second metal nitride layer formed on the silicon film, and a metal layer formed on the metal nitride layer.

Abstract: The present invention relates to semiconductor devices, and more particularly to a process and structure for removing a dielectric spacer selective to a surface of a semiconductor substrate with substantially no removal of the semiconductor substrate. The method of the present invention can be integrated into a conventional CMOS processing scheme or into a conventional BiCMOS processing scheme. The method includes forming a field effect transistor on a semiconductor substrate, the FET comprising a dielectric spacer and the gate structure, the dielectric spacer located adjacent a sidewall of the gate structure and over a source/drain region in the semiconductor substrate; depositing a first nitride layer over the FET; and removing the nitride layer and the dielectric spacer selective to the semiconductor substrate with substantially no removal of the semiconductor substrate.

Abstract: A method for fabricating a semiconductor device includes forming a recess pattern by selectively etching a substrate; forming a gate dielectric layer filling the recess pattern on the substrate; forming a groove by selectively etching the gate dielectric layer; forming a polysilicon electrode filling the groove; forming an electrode metal layer on the polysilicon electrode and the gate dielectric layer; and forming a gate pattern by etching the electrode metal layer and the gate dielectric layer. The recess pattern is formed along an edge portion of the gate pattern as a quadrilateral periphery.

Abstract: This disclosure concerns a manufacturing method of a semiconductor device includes forming a Fin-type body on an insulation layer, the Fin-type body being made of a semiconductor material and having an upper surface covered with a protective film; forming a gate insulation film on side surfaces of the Fin-type body; depositing a gate electrode material so as to cover the Fin-type body; planarizing the gate electrode material; forming a gate electrode by processing the gate electrode material; depositing an interlayer insulation film so as to cover the gate electrode; exposing the upper surface of the gate electrode; depositing a metal layer on the upper surface of the gate electrode; siliciding the gate electrode by reacting the gate electrode with the metal layer; forming a trench on the upper surface of the protective film by removing an unreacted metal in the metal layer; and filling the trench with a conductor.

Abstract: The present disclosure describes methods for preparing semiconductor structures, comprising forming a Ge layer on a semiconductor substrate using an admixture of (a) (GeH3)2CH2 and Ge2H6; (b) GeH3CH3 and Ge2H6; or (c) (GeH3)2CH2, GeH3CH3 and Ge2H6, wherein in all cases, Ge2H6 is in excess. The disclosure further provides semiconductor structures formed according to the methods of the invention as well as compositions comprising an admixture of (GeH3)2CH2 and/or GeH3CH3 and Ge2H6 in a ratio of between about 1:5 and 1:30. The methods herein provide, and the semiconductor structures provide, Ge layers formed on semiconductor substrates having threading dislocation density below 105/cm2 which can be useful in semiconductor devices.

Abstract: Measuring the amount of unreacted polysilicon gate material in a fully silicided (FUSI) nickel silicide gate process for metal oxide semiconductor (MOS) transistors in an integrated circuit (IC) to guide process development and monitor IC production requires a statistically significant sample size and an economical procedure. A method is disclosed which includes a novel deprocessing sequence of oxidizing the nickel followed by removing the nickel silicide by acid etching, acquiring an SEM image of a deprocessed area encompassing a multitude of gates, forming a quantifiable mask of the original gate area in the SEM image, forming a quantifiable image of the unreacted polysilicon area in the SEM image, and computing a fraction of unreacted polysilicon.

Abstract: A method is disclosed for forming at least two semiconductor devices with different gate electrode thicknesses. After forming a gate dielectric region, and determining whether a first or second device formed on the gate dielectric region expects a relatively faster gate dopant diffusion rate, a gate electrode layer is formed on the gate dielectric region wherein the gate electrode layer has a step-structure in which a portion thereof for the first device has a relatively larger thickness than that for the second device if the first device has a relatively faster gate dopant diffusion rate.

Abstract: In a metal gate replacement process, strain may be selectively induced in the channels of NMOS and PMOS transistors. For example, a material having a higher coefficient of thermal expansion than the substrate may be used to form the gate electrodes of PMOS transistors. A material with a lower coefficient of thermal expansion than that of the substrate may be used to form the gate electrodes of NMOS transistors.

Abstract: A semiconductor device may include a gate insulating layer on a semiconductor substrate, a polysilicon layer doped with impurities on the gate insulating layer, an interface reaction preventing layer on the polysilicon layer, a barrier layer on the interface reaction preventing layer, and a conductive metal layer on the barrier layer. The interface reaction preventing layer may reduce or prevent the occurrence of a chemical interfacial reaction with the barrier layer, and the barrier layer may reduce or prevent the diffusion of impurities doped to the polysilicon layer. The interface reaction preventing layer may include a metal-rich metal silicide having a metal mole fraction greater than a silicon mole fraction, so that the interface reaction preventing layer may reduce or prevent the dissociation of the barrier layer at higher temperatures. Thus, a barrier characteristic of a poly-metal gate electrode may be improved and surface agglomerations may be reduced or prevented.

Abstract: A plurality of spaced-apart conductor structures is formed on a semiconductor substrate, each of the conductor structures including a conductive layer. Insulating spacers are formed on sidewalls of the conductor structures. An interlayer-insulating film that fills gaps between adjacent ones of the insulating spacers is formed. Portions of the interlayer-insulating layer are removed to expose upper surfaces of the conductive layers. Respective epilayers are grown on the respective exposed upper surfaces of the conductive layers and respective metal silicide layers are formed from the respective epilayers.

Abstract: In one aspect, an image sensor is provided which includes an active pixel array and a control circuit connected to the active pixel array. The active pixel array of this aspect includes a plurality of first gate dielectric layers, and the control circuit includes a plurality of second gate dielectric layers, where the first gate dielectric layers are plasma nitrided silicon oxide layers.

Abstract: A gate of a transistor includes a gate oxide layer formed on a semiconductor device, a first conductive layer pattern including polysilicon doped with boron and formed on the gate oxide layer, a diffusion preventing layer pattern including amorphous silicon formed by a chemical vapor deposition process using a reaction gas having trisilane (Si3H8) and formed on the first conductive layer pattern, and a second conductive layer pattern including metal silicide and formed on the diffusion preventing layer pattern. Since a gate of PMOS transistor includes a diffusion preventing layer having an excellent surface morphology, diffusion of impurities is sufficiently prevented. Thus, the threshold voltage of PMOS transistor may be reduced and threshold voltage distribution may be improved.

Abstract: In a method for manufacturing a semiconductor device, an insulating film is formed on an entire surface of a substrate having a device isolation region and a first and a second conductive region. Then, a semiconductor device structure having a gate electrode forming region is formed on each of the conductive regions, the insulating film being disposed between the gate electrode forming region and each of the conductive regions. A gate electrode groove is formed in the gate electrode forming region of the semiconductor device structure, the insulating film being removed in the gate electrode groove. Thereafter, a gate insulating film and a film of metal gate electrode material are deposited on a bottom surface and a side surface of the gate electrode groove and an alloy is formed by alloying the film of metal gate electrode material deposited in a gate electrode groove of the first conductive region.

Abstract: A method for forming a semiconductor structure includes providing a semiconductor substrate; forming a gate dielectric layer on the semiconductor substrate; forming a metal-containing layer on the gate dielectric; and forming a composite layer over the metal-containing layer. The step of forming the composite layer includes forming an un-doped silicon layer substantially free from p-type and n-type impurities; and forming a silicon layer adjoining the un-doped silicon layer. The step of forming the silicon layer comprises in-situ doping a first impurity. (or need to be change to: forming a silicon layer first & then forming un-doped silicon layer) The method further includes performing an annealing to diffuse the first impurity in the silicon layer into the un-doped silicon layer.

Abstract: A method for fabricating a semiconductor structure is disclosed. A substrate with a first transistor having a first dummy gate and a second transistor having a second dummy gate is provided. The conductive types of the first transistor and the second transistor are different. The first and second dummy gates are simultaneously removed to form respective first and second openings. A high-k dielectric layer, a second type conductive layer and a first low resistance conductive layer are formed on the substrate and fill in the first and second openings, with the first low resistance conductive layer filling up the second opening. The first low resistance conductive layer and the second type conductive layer in the first opening are removed. A first type conductive layer and a second low resistance conductive layer are then formed in the first opening, with the second low resistance conductive layer filling up the first opening.

Abstract: A semiconductor device includes an Nch transistor having a first gate electrode and a Pch transistor having a second gate electrode. The first gate electrode and the second gate electrode are made of materials causing stresses of different magnitudes.

Abstract: Embodiments of the invention provide a semiconductor integrated circuit device and a method for fabricating the device. In one embodiment, the method comprises forming a plurality of preliminary gate electrode structures in a cell array region and a peripheral circuit region of a semiconductor substrate; forming selective epitaxial films on the semiconductor substrate in the cell array region and the peripheral region; implanting impurities into at least some of the selective epitaxial films to form elevated source/drain regions in the cell array region and the peripheral circuit region; forming a first interlayer insulating film; and patterning the first interlayer insulating film to form a plurality of first openings exposing the elevated source/drain regions. The method further comprises forming a first ohmic film, a first barrier film, and a metal film; and removing portions of each of the metal film, the first barrier film, and the first ohmic film.

Abstract: Substrate devices having tuned work functions and methods of forming thereof are provided. In some embodiments, forming devices on substrates may include depositing a dielectric layer atop a substrate having a conductivity well; depositing a work function layer comprising titanium aluminum or titanium aluminum nitride having a first nitrogen composition atop the dielectric layer; etching the work function layer to selectively remove at least a portion of the work function layer from atop the dielectric layer; depositing a layer comprising titanium aluminum or titanium aluminum nitride having a second nitrogen composition atop the work function layer and the substrate, wherein at least one of the work function layer or the layer comprises nitrogen; etching the layer and the dielectric layer to selectively remove a portion of the layer and the dielectric layer from atop the substrate; and annealing the substrate at a temperature less than about 1500 degrees Celsius.

Abstract: The present disclosure provides a method of fabricating a semiconductor device that includes providing a substrate having a first region and a second region, forming first and second gate stacks in the first and second regions, respectively, the first gate stack including a first dummy gate and the second gate stack including a second dummy gate, removing the first dummy gate in the first gate stack thereby forming a first trench and removing the second dummy gate in the second gate stack thereby forming a second trench, forming a first metal layer in the first trench and in the second trench, removing at least a portion of the first metal layer in the first trench, forming a second metal layer in the remainder of the first trench and in the remainder of the second trench, reflowing the second metal layer, and performing a chemical mechanical polishing (CMP).

Abstract: A flash memory device and method of fabricating thereof. In accordance with the method of the invention, a tunnel dielectric layer and an amorphous first conductive layer are formed over a semiconductor substrate. An annealing process to change the amorphous first conductive layer to a crystallized first conductive layer is performed. A second conductive layer is formed on the crystallized first conductive layer. A first etch process to pattern the second conductive layer is performed. A second etch process to remove an oxide layer on the crystallized first conductive layer is performed. A third etch process to pattern the amorphous first conductive layer is performed.

Abstract: Various embodiments of the invention relate to a PMOS device having a transistor channel of silicon germanium material on a substrate, a gate dielectric having a dielectric constant greater than that of silicon dioxide on the channel, a gate electrode conductor material having a work function in a range between a valence energy band edge and a conductor energy band edge for silicon on the gate dielectric, and a gate electrode semiconductor material on the gate electrode conductor material.

Abstract: A transistor structure includes a semiconductor substrate with a first surface, a diffusion region at the first surface of the substrate, a sacrificial gate formed on the diffusion region, and insulating side walls formed adjacent to the sacrificial gate. A metal gate is formed by etching out the sacrificial gate and filling in the space between the insulating side walls with gate metals. Silicided source and drain contacts are formed over the diffusion region between the side walls of two adjacent aluminum gates. One or more oxide layers are formed over the substrate. Vias are formed in the oxide layers by plasma etching to expose the silicided source and drain contacts, which simultaneously oxidizes the aluminum gate metal. A first metal is selectively formed over the silicided contact by electroless deposition, but does not deposit on the oxidized aluminum gate.

Abstract: Semiconductor device performance is improved via a gate structure having a tunable effective workfunction and reduced gate depletion effects. According to an example embodiment, the design threshold voltage of a semiconductor device is adjusted in a manner that includes providing a gate having a workfunction that enables operation of the semiconductor device at a selected voltage. The gate is formed having two different conductive materials with different electric workfunctions that both significantly contribute to the overall workfunction of the gate. The relative composition, thickness, and arrangement of each of the two conductive materials is selected to attain a gate electrode workfunction that is different than the workfunctions of each of the two layers and that sets the threshold voltage of the semiconductor device. The adjustability of the effective workfunction of the gate electrode can be applied to a variety of semiconductor devices.

Abstract: A system and method are disclosed for processing a zero angstrom oxide interface dual poly gate structure for a flash memory device. An exemplary method can include removing an oxide on a surface of a first poly layer and forming a second poly layer on the first poly layer in a same processing chamber. A transfer of the structure is not needed from an oxide removal tool to, for example, a poly layer formation tool, an implant tool, and the like. As a result, impurities containing a silicon oxide caused by exposure of the first poly layer to an oxygen-containing atmosphere do not form at the interface of the first and second poly layers.

Abstract: A method for fabricating a CMOS structure is disclosed. The method includes the blanket disposition of a high-k gate insulator layer in an NFET device and in a PFET device, and the implementation of a gate metal layer over the NFET device. This is followed by a blanket disposition of an Al layer over both the NFET device and the PFET device. The method further involves a blanket disposition of a shared gate metal layer over the Al layer. When the PFET device is exposed to a thermal annealing, the high-k dielectric oxidizes the Al layer, thereby turning the Al layer into a PFET interfacial control layer, while in the NFET device the Al becomes a region of the metal gate.

Abstract: A method of depositing a bilayer of tungsten over tungsten nitride by a plasma sputtering process in which krypton is used as the sputter working gas during the tungsten deposition. Argon may be used as the sputtering working gas during the reactive sputtering deposition of tungsten nitride. The beneficial effect of reduction of tungsten resistivity is increased when the thickness of the tungsten layer is less than 50 nm and further increased when less than 35 nm. The method may be used in forming a gate stack including a polysilicon layer over a gate oxide layer over a silicon gate region of a MOS transistor in which the tungsten nitride acts as a barrier. A plasma sputter chamber in which the invention may be practiced includes gas sources of krypton, argon, and nitrogen.

Abstract: There is provided a method for cleaning a semiconductor device capable of making compatible the inhibition of dissolution of a gate metal material and the acquisition of a favorable contact resistance.

Abstract: A method is disclosed to reduce parasitic capacitance in a metal high dielectric constant (MHK) transistor. The method includes forming a MHK gate stack upon a substrate, the MHK gate stack having a bottom layer of high dielectric constant material, a middle layer of metal, and a top layer of one of amorphous silicon or polycrystalline silicon. The method further forms a depleted sidewall layer on sidewalls of the MHK gate stack so as to overlie the middle layer and the top layer, and not the bottom layer. The depleted sidewall layer is one of amorphous silicon or polycrystalline silicon. The method further forms an offset spacer layer over the depleted sidewall layer and over exposed surfaces of the bottom layer.

Abstract: Provided is a highly reliable semiconductor device equipped with a plurality of semiconductor elements having desired properties, respectively; and a manufacturing method facilitating the manufacture of the semiconductor device. The semiconductor device is manufactured by forming a gate-electrode metal film having a thickness of from 3 to 30 nm over the entire upper surface of a gate insulating film; forming an n-side cap layer having a thickness of 10 nm or less over the entire upper surface of a portion of the gate-electrode metal film belonging to an nFET region by using a material different from that of the gate-electrode metal film; and carrying out heat treatment over the n-side cap layer to diffuse the material of the n-side cap layer into the gate-electrode metal film immediately below the n-side cap layer and react them to form an n-side gate-electrode metal film in a nFET region. A poly-Si layer is then deposited, followed by gate electrode processing.

Abstract: A gate-last method for forming a metal gate transistor is provided. The method includes forming an opening within a dielectric material over a substrate. A gate dielectric structure is formed within the opening and over the substrate. A work function metallic layer is formed within the opening and over the gate dielectric structure. A silicide structure is formed over the work function metallic layer.

Abstract: A method for forming a Field Effect Transistor (FET) within a strain effect semiconductor layer is disclosed, whereby the source and drain of the FET are formed only in the strain effect silicon layer. The FET may be formed as a gate electrode of a p-channel type field effect transistor, and a gate electrode of a n-channel type field effect transistor on the silicon layer which has the strain effect through a gate insulating film. The sources and drains of p- and n-type diffusion layers are then formed in the silicon layer having the strain effect, on both sides of the gate electrode.

Abstract: A semiconductor device is provided including a transistor element on a substrate, a silicide on a gate and a source/drain of the transistor element; and an amorphous capping layer on the silicide.

Abstract: A layer-stacked wiring made up of a microcrystalline silicon thin film and a metal thin film is provided which is capable of suppressing an excessive silicide formation reaction between the microcrystalline silicon thin film and metal thin film, thereby preventing peeling of the thin film. In a polycrystalline silicon TFT (Thin Film Transistor) using the layer-stacked wiring, the microcrystalline silicon thin film is so configured that its crystal grains each having a length of the microcrystalline silicon thin film in a direction of a film thickness being 60% or more of a film thickness of the microcrystalline silicon thin film amount to 15% or less of total number of crystal grains or that its crystal grains each having a length of the microcrystalline silicon thin film in a direction of a film thickness being 50% or less of a film thickness of the microcrystalline silicon thin film amount to 85% or more of the total number of crystal grains making up the microcrystalline silicon thin film.

Abstract: A flash memory device includes a tunnel insulating layer formed over a semiconductor substrate, a charge trap layer formed over the tunnel insulating layer and configured to trap electric charges, a blocking insulating layer formed over the charge trap layer, and a gate electrode formed over the blocking insulating layer and including a first conductive layer and a second conductive layer doped with N and P impurities respectively. Further, a method of erasing a flash memory device includes providing a flash memory device including a gate electrode having a first conductive layer and a second conductive layer doped with N and P impurities respectively, and performing an erase operation in a state where a thickness of a depletion layer at an interface of a PN junction comprising the first conductive layer and the second conductive layer is increased due to a negative potential bias applied to the gate electrode.

Abstract: A gate dielectric film, a poly-silicon film, a film of a refractory metal such as tungsten, and a gate cap dielectric film are sequentially laminated on a semiconductor substrate. The gate cap dielectric film and the refractory metal film are selectively removed by etching. Thereafter, a double protection film including a silicon nitride film and a silicon oxide film is formed on side surfaces of the gate cap dielectric film, the refractory metal film, and the poly-silicon film. The poly-silicon film is etched using the double protection film as a mask. Thereafter, the semiconductor substrate is light oxidized to form a silicon oxide film on side surfaces of the poly-silicon film. Accordingly, a junction leakage of a MOSFET having a gate electrode of a poly-metal structure, particularly, a memory cell transistor of a DRAM, can be further reduced.