Abstract: A zero threshold voltage (ZVt) pFET (104) and a method of making the same. The ZVt pFET is made by implanting a p-type substrate (112) with a retrograde n-well (116) so that a pocket (136) of the p-type substrate material remains adjacent the surface of the substrate. This is accomplished using an n-well mask (168) having a pocket-masking region (184) in the aperture (180) corresponding to the ZVt pFET. The n-well may be formed by first creating a ring-shaped precursor n-well (116′) and then annealing the substrate so as to cause the regions of the lower portion (140′) of the precursor n-well to merge with one another to isolate the pocket of p-type substrate material. After the n-well and isolated pocket of p-type substrate material have been formed, remaining structures of the ZVt pFET may be formed, such as a gate insulator (128), gate (132), source (120), and drain (124).

Abstract: A short-channel NMOS transistor in a p-well, bordered laterally on each side by an isolation region and vertically by a channel stop region, has a n-source and a n-drain, each comprising a shallow region extending to the transistor gate and a deeper region recessed from the gate, and both having a depletion region when reverse biased. The shallow regions are surrounded in part by an enhanced p-doping implant pocket. The transistor further has in these regions of enhanced p-doping another region of a p-resistivity higher than the remainder of the semiconductor. These regions extend laterally approximately from the inner border of the respective shallow region to the inner border of the respective recessed region, and vertically from a depth just below the depletion regions of source and drain to approximately the top of the channel stop regions.

Abstract: Fin-type field effect transistors are fabricated on a semiconductor substrate. Rectangular fins are formed on the substrate in a rectangular pattern of rows and columns and gate electrodes are deposited on at least two sides of the fins. The gate electrodes are implanted with ions at an angle &thgr; to a line perpendicular to the substrate, such that D≈H tan &thgr;, where D is the distance between fins in adjacent rows or columns and H is the height of the fins.

Abstract: A semiconductor device has a structure in which an impurity diffusion region with an impurity concentration lower than an impurity concentration of a source and a drain is formed between the source and drain and a channel below the gate, having an asymmetric shape with respect to a center line along which the gate extends.

Abstract: The invention relates to a method of adjusting the erase/program voltage in semiconductor non-volatile memories. The memories are formed of at least one matrix of memory cells having a floating gate, a control gate, and drain and source terminals, and are organized by the byte in rows and columns, each byte comprising a group of cells having respective control gates connected in parallel with one another to a common control line through a selection element of the byte switch type, and each cell being connected to a respective control column through a selection element of the bit switch type. Advantageously, a double adjustment is provided for the program voltage of the memory cells, whereby the program voltage during the erasing phase can be higher in modulo than the program voltage during the writing phase.

Abstract: Structures for providing devices that include resistive paths specifically designed to provide a predetermined resistance between the bulk material of the device and a well tie contact. By providing a resistive path, an equivalent RC circuit is introduced to the device that allows the bulk material potential to track the gate potential, thereby advantageously lowering the threshold voltage as the device turns on and raising the threshold voltage as the device turns off. In addition, the introduction of the resistive path also allows the bulk material potential to be controlled and stabilize at an equilibrium potential between switching events.

Abstract: A semiconductor device according to the present invention includes a memory region in which a memory cell array is formed of non-volatile memory devices arranged in a matrix of a plurality of rows and columns. Each of the nonvolatile memory devices includes a word gate formed over a semiconductor layer with a gate insulating layer interposed in between, impurity layers formed in the semiconductor layer, and sidewall-shaped control gates formed along both side surfaces of the word gate. The control gate includes a first control gate and a second control gate which are adjacent to each other. The first control gate is formed on a first insulating layer formed of a first silicon oxide film, a silicon nitride film, and a second silicon oxide film. The second control gate is formed on a second insulating layer formed of a silicon oxide film.

Abstract: A power MOSFET includes a semiconductor substrate having a drift region therein and a transition region that extends between the drift region and a first surface of the semiconductor substrate. The transition region has a vertically retrograded doping profile therein that peaks at a first depth relative to the first surface. An insulated gate electrode is provided that extends on the first surface and has first and second opposing ends. First and second base regions of second conductivity type are provided in the substrate. The first and second base regions are self-aligned to the first and second ends of the insulated gate electrode, respectively, and form respective P-N junctions with opposing sides of an upper portion of the transition region extending adjacent the first surface. First and second source regions are provided in the first and second base regions, respectively.

Abstract: The invention concerns a semi-conductor device comprising on a substrate: a first dynamic threshold voltage MOS transistor (10), with a gate (116), and a channel (111) of a first conductivity type, and a current limiter means (20) connected between the gate and the channel of said first transistor. In accordance with the invention, this first transistor is fitted with a first doped zone (160) of the first conductivity type, connected to the channel, and the current limiter means comprises a second doped zone (124) of a second conductivity type, placed against the first doped zone and electrically connected to the first zone by an ohmic connection. Application to the manufacture of CMOS circuits.

Abstract: Power MOSFET devices provide highly linear transfer characteristics (e.g., Id v. Vg) and can be used effectively in linear power amplifiers. These linear transfer characteristics are provided by a device having a channel that operates in a linear mode and a drift region that simultaneously supports large voltages and operates in a current saturation mode. A relatively highly doped transition region is provided between the channel region and the drift region. Upon depletion, this transition region provides a potential barrier that supports simultaneous linear and current saturation modes of operation. Highly doped shielding regions may also be provided that contribute to depletion of the transition region.

Abstract: A semiconductor device comprises at least a semiconductor layer including source and drain areas of a first conductive type and of a high impurity concentration and a channel area positioned between the source and drain areas, an insulation layer covering at least the channel area, and a gate electrode positioned close to the insulation layer. The channel area at least comprises a first channel area of a low resistance, positioned close to the insulation layer and having a second conductive type opposite to the first conductive type, and a second channel area of a high resistance, having the first conductive type and positioned adjacent to the first channel area.

Abstract: Structures for providing devices that include resistive paths specifically designed to provide a predetermined resistance between the bulk material of the device and a well tie contact. By providing a resistive path, an equivalent RC circuit is introduced to the device that allows the bulk material potential to track the gate potential, thereby advantageously lowering the threshold voltage as the device turns on and raising the threshold voltage as the device turns off. In addition, the introduction of the resistive path also allows the bulk material potential to be controlled and stabilize at an equilibrium potential between switching events.

Abstract: A power field effect transistor utilizes a retrograded-doped transition region to enhance forward on-state and reverse breakdown voltage characteristics. Highly doped shielding regions may also be provided that extend adjacent the transition region and contribute to depletion of the transition region during both forward on-state conduction and reverse blocking modes of operation. In a vertical embodiment, the transition region has a peak first conductivity type dopant concentration at a first depth relative to a surface on which gate electrodes are formed. A product of the peak dopant concentration and a width of the transition region at the first depth is preferably in a range between 1×1012 cm−2 and 7×1012 cm−2.

Abstract: Structures for providing devices that include resistive paths specifically designed to provide a predetermined resistance between the bulk material of the device and a well tie contact. By providing a resistive path, an equivalent RC circuit is introduced to the device that allows the bulk material potential to track the gate potential, thereby advantageously lowering the threshold voltage as the device turns on and raising the threshold voltage as the device turns off. In addition, the introduction of the resistive path also allows the bulk material potential to be controlled and stabilize at an equilibrium potential between switching events.

Abstract: A trench MOSFET transistor device and method of making the same are provided. The trench MOSFET transistor device comprises: (a) a drain region of first conductivity type; (b) a body region of a second conductivity type provided over the drain region, such that the drain region and the body region form a first junction; (c) a source region of the first conductivity type provided over the body region, such that the source region and the body region form a second junction; (d) source metal disposed on an upper surface of the source region; (e) a trench extending through the source region, through the body region and into the drain region; and (f) a gate region comprising (i) an insulating layer, which lines at least a portion of the trench and (ii) a conductive region, which is disposed within the trench adjacent the insulating layer. The body region in this device is separated from the source metal.

Abstract: A nonvolatile semiconductor memory device according to the present invention has a control gate electrode which is formed on the upper stage of a stepped portion formed in the principal surface of a substrate with a first insulating film interposed therebetween and a floating gate electrode which is formed to cover up the stepped portion, capacitively coupled to the side surface of the control gate electrode closer to the stepped portion with a second insulating film interposed therebetween, and opposed to the lower stage of the stepped portion with a third insulating film serving as a tunnel film interposed therebetween.

Abstract: A semiconductor device has a first semiconductor region formed in a semiconductor substrate and having a first conductivity type due to first-conductivity-type active impurities contained in the first semiconductor region, and a second semiconductor region formed between the first semiconductor region and the surface of the semiconductor substrate and having a second conductivity type due to second-conductivity-type active impurities contained in the second semiconductor region. The second semiconductor region contains first-conductivity-type active impurities whose concentration is zero or smaller than a quarter of a concentration of the second-conductivity-type active impurities contained in the second semiconductor region. An insulating film and a conductor are formed on the second semiconductor region. Third and fourth semiconductor regions of the second conductivity type are formed at the semiconductor surface in contact with the side faces of the second semiconductor region.

Abstract: A metal-oxide-silicon (MOS) device that at least includes a silicon-based substrate, a nanometer scaled oxide layer formed on the silicon-based substrate and a metal layer formed on the oxide layer, is disclosed. The present invention basically uses a nanometer scaled oxide structure that result in a non-uniform tunneling current to enhance light-emitting efficiency. The manufacturing steps of the MOS device according to the present invention are quite similar to those of conventional MOS device, so the MOS device according to the present invention can be integrated with the current silicon-based integrated circuit chip. Further the application fields of the silicon-based chip and material can be extended. The cost of MOS device can be reduced and its practicality can be increased.

Abstract: A high voltage MOS transistor is provided that is compatible with low-voltage, sub-micron CMOS and BiCMOS processes. The high voltage transistor of the present invention has dopants that are implanted into the substrate prior to formation of the epitaxial layer. The implanted dopants diffuse into the epitaxial layer from the substrate during the formation of the epitaxial layer and subsequent heating steps. The implanted dopants increase the doping concentration in a lower portion of the epitaxial layer. The implanted dopants may diffuse father into the epitaxial layer than dopants in the buried layer forming an up-retro well that prevents vertical punch-through at high operating voltages for thin epitaxial layers. In addition, the doping concentration below the gate may be light so that the threshold voltage of the transistor is low.

Abstract: Methods of forming a channel region between isolation regions of an integrated circuit substrate are disclosed. In particular, a mask can be formed on an isolation region that extends onto a portion of the substrate adjacent to the isolation region to provide a shielded portion of the substrate adjacent to the isolation region and an exposed portion of the substrate spaced apart from the isolation region having the shielded portion therebetween. A channel region can be formed in the exposed portion of the substrate. Related integrated circuits are also discussed.

Abstract: A silicon film provided on a blocking film 102 on a substrate 101 is made amorphous by doping Si+, and in a heat-annealing process, crystallization is started in parallel to a substrate from an area 100 where nickel serving as a crystallization-promoting catalyst is introduced.

Abstract: A flash memory with a self-aligned spilt gate and the methods for fabricating and operating the same are described. The flash cell consists of a substrate having a deep n-type well and a shallow p-type well in the deep n-type well therein, a control gate structure on the gate oxide layer located on the p-type shallow well, a floating gate on one sidewall of the control gate and over the substrate, a tunnel oxide layer between the control gate and the floating gate and between the floating gate and the substrate, a drain and a common source disposed beneath each side of the control gate in the substrate, wherein the depth of the drain and the common source are larger than the depth of the shallow p-type well, a pocket p-type well in the substrate around the drain and electrically connecting with the shallow p-type well.

Abstract: A halo implant (42, 44) for an MOS transistor (10) is formed in a semiconductor substrate (12) at a shallow implant angle, relative to normal to the substrate surface (29). A polysilicon gate structure (32, 33) is formed over a gate oxide (28) and then a hard mask (70), such as a TEOS-generated layer of silicon oxide, is deposited on an upper surface (68) of the gate. The mask is etched with a blanket anisotropic etch to form a cap-shaped mask (72). The shape of the cap causes the dopant for the halo implant to penetrate to a depth which follows the contour of the cap. Thus, halo implants may be formed which extend under the gate structure without the need for large angle implants and resultant shadowing problems caused by adjacent devices.

Abstract: A method and apparatus for providing a meshed power and signal bus system on an array type integrated circuit that minimizes the size of the circuit. In a departure from the art, through-holes for the mesh system are placed in the cell array, as well as the peripheral circuits. The power and signal buses of the mesh system run in both vertical and horizontal directions across the array such that all the vertical buses lie in one metal layer, and all the horizontal buses lie in another metal layer. The buses of one layer are connected to the appropriate bus(es) of the other layer using through-holes located in the array. Once connected, the buses extend to the appropriate sense amplifier drivers. The method and apparatus are facilitated by an improved subdecoder circuit implementing a hierarchical word line structure.

Abstract: Memory elements, switching elements, and peripheral circuits to constitute a nonvolatile memory are integrally formed on a substrate by using TFTs. Since semiconductor active layers of memory element TFTs are thinner than those of other TFTs, impact ionization easily occurs in channel regions of the memory element TFTs. This enables low-voltage write/erase operations to be performed on the memory elements, and hence the memory elements are less prone to deteriorate. Therefore, a nonvolatile memory capable of miniaturization can be provided.

Abstract: High performance asymmetric transistors including controllable diode characteristics at the source and/or drain are developed by supplying impurities with high accuracy of location by angled implants in a trench or diffusion from a solid body formed as a sidewall of doped material. High concentration gradient of impurities to support high performance is achieved by providing for reduced heat treatment after the impurity is supplied in order to limit diffusion previously necessary to achieve the desired location of impurity structures. Damascene or quasi-Damascene gate structures are also provided for high dimensional uniformity, increased manufacturing yield and structural integrity of the transistor.

Abstract: A nonvolatile semiconductor memory comprises a pair of diffused layers formed in the surface area of a p-type silicon substrate, and a gate electrode (polysilicon film and tungsten silicide film formed on a gate oxide between the diffused layers over the p-type silicon substrate. Silicon nitride film is formed at both ends of the gate oxide so that the carrier trap characteristic may become high locally in areas near the pair of diffused layer. This configuration prevents carrier injection to other than the ends of the gate oxide, ensures reliable recording and storage, and increases reliability by preventing write and erase error.

Abstract: A semiconductor device and a method for forming the same are disclosed. The semiconductor device includes an epitaxial source/drain junction layer having an insulating film thereunder. The method comprises the step of forming a under-cut under an epitaxial source/drain junction layer so that an insulating film filling the under-cut can be formed.

Abstract: A surface-channel MOS transistor comprising; a gate electrode formed on a semiconductor substrate with a gate dielectric film therebetween and source/drain regions formed in the semiconductor substrate wherein the gate electrode is formed at least a polysilicon layer of a thickness of 100 to 200 nm uniformly doped with an impurity and the source/drain regions contains the same impurity in self-alignment with the gate electrode.

Abstract: A zero power memory cell includes first and second NMOS transistors and a PMOS transistor, wherein the first NMOS transistor and first PMOS transistor each include a three-implant channel region, and wherein the second NMOS transistor further includes a two-implant channel region.

Abstract: A method of fabricating a transistor comprises forming a gate structure outwardly of a semiconductor substrate, wherein the gate structure comprises a gate, a gate insulator and sidewalls and forming source region and a drain region in the substrate using the gate structure as a mask, wherein a channel is defined in the substrate between the source region and the drain region. A bottomwall/sidewall junction capacitance reduction region extending within and between the source region and the drain region is formed, wherein the bottomwall/sidewall junction capacitance reduction region extends at least partially through the bottomwall junction or the sidewall junction.

Abstract: An active negative differential resistance element (an NDR FET) and a memory device (such as an SRAM) using such elements is disclosed. Soft error rate (SER) performance for NDR FETs and such memory devices are enhanced by adjusting a location of charge traps in a charge trapping layer that is responsible for effectuating an NDR behavior. Both an SER and a switching speed performance characteristic can be tailored by suitable placement of the charge traps.

Abstract: The present invention includes a semiconductor device having a shallow trench isolation and a method of fabricating the same. The semiconductor device includes a gate electrode being arranged to cross over the active region. An oxide pattern is interposed between the active region and the edge of the gate electrode. The oxide pattern defines a channel region under the gate electrode. A lightly doped diffusion layer is formed in the active region downward and outward from the oxide pattern, and a heavy doped diffusion layer is formed in a predetermined region of the active region and surrounded by the lightly doped diffusion layer. In the method of fabricating the semiconductor substrate, a trench isolation layer is formed at a predetermined region of a semiconductor substrate to define an active region. A pair of preliminary lightly doped diffusion layers are formed in a line to cross over the active region. Then, oxide patterns are formed to cover at least the preliminary lightly doped diffusion layers.

Abstract: A non-volatile multiple bit memory (10, 50) has electrically isolated storage elements (17, 21, 78, 80) that overlie a channel region having a central area (24, 94) with high impurity concentration. A planar gate (30, 84) overlies the storage elements. The high impurity concentration may be formed by a centrally located region (24) or by two peripheral regions (70, 72) having lower impurity concentration than the central portion of the channel. During a read or program operation, the channel area of high impurity concentration effectively controls a channel depletion region to enhance reading or programming of stored data bits. During a hot carrier program operation, the channel area of high impurity concentration enhances the programming efficiency by decreasing leakage currents in a memory array.

Abstract: A high withstand voltage insulated gate N-channel field effect transistor has N-type source and drain regions formed on a semiconductor substrate, and a channel forming region disposed between the source and drain regions. A gate insulating film is disposed over the channel forming region. A gate electrode is formed on the channel forming region through the gate insulating film. N-type low concentration regions are formed between respective ones of the drain region and the channel forming region and the source region and the channel forming region. Second insulating films are formed on respective ones of the low concentration regions. A P-type buried layer is formed in a boundary region between the semiconductor substrate and the epitaxial layer and below the source region, the drain region, the channel forming region, the gate insulating film, and the second insulating films. A P-type well layer is formed in a part of a region under the gate insulating film.

Abstract: A functional device free from cracking and having excellent functional characteristics, and a method of manufacturing the same are disclosed. A low-temperature softening layer (12) and a heat-resistant layer (13) are formed in this order on a substrate (11) made of an organic material such as polyethylene terephthalate, and a functional layer (14) made of polysilicon is formed thereon. The functional layer (14) is formed by crystallizing an amorphous silicon layer, which is a precursor layer, with laser beam irradiation. When a laser beam is applied, heat is transmitted to the substrate (11) and the substrate (11) tends to expand. However, a stress caused by a difference in a thermal expansion coefficient between the substrate (11) and the functional layer (14) is absorbed by the low-temperature softening layer (12), so that no cracks and peeling occurs in the functional layer (14). The low-temperature softening layer (12) is preferably made of a polymeric material containing an acrylic resin.

Abstract: When polycrystalline silicon germanium film is used for gate electrodes in a MOS transistor apparatus, there have been problems of reduced reliability in the gate insulating film, due to stress in the silicon germanium grains. Therefore, a polysilicon germanium film is formed, after forming silicon fine particles of particle size 10 nm or less on an oxide film. As a result, it is possible to achieve a high-speed MOS transistor apparatus using an ultra-thin oxide film having a film thickness of 1.5 nm or less, wherein the Ge concentration of the polycrystalline silicon germanium at its interface with the oxide film is uniform, thereby reducing the stress in the film, and improving the reliability of the gate electrode.

Abstract: A MOSFET with low leakage current and method. The MOSFET has a substrate, a channel region, a source/drain region, a gate oxide layer and a conductive layer. The channel region in the substrate has a first region and a second region. The first region has a first threshold voltage and the second region has a second threshold voltage, respectively. The second region is located between the first region and the source/drain region. The first threshold voltage is smaller than the second threshold voltage. The leakage current of the MOSFET has an appropriate reduction by increasing the second threshold voltage of the second region. Significantly, by adjusting the size and position of the second region of the channel region, both the leakage current and the drain current of the MOSFET are readily optimized.

Abstract: Impurity regions 110 that can form an energy barrier are artificially and locally disposed in a channel formation region 111. The impurity regions 110 restrain a depletion layer that extends from a drift region 102 toward a channel formation region 111, and prevents a short channel effect caused by the depletion layer, with the result that an insulated gate semiconductor device high in withstand voltage can be manufactured without lowering the operation speed.

Abstract: An improved DMOS power transistor (20) with a single p-body implant (12) and including an n-type channel compensating implant (NCCI) (24). The improved DMOS power transistor (20) provides a more favorable trade-off between threshold voltage (VT) and on-state resistance, while increasing the safe operating area (SOA). The NCCI (24) also improves the off-state breakdown voltage, and allows a larger fraction of the gate bias voltage to be supported on the thin gate oxide (32). The present invention can be fabricated using self-aligned fabrication techniques so that the channel length (22) is insensitive to lithography equipment.

Abstract: The invention includes a semiconductor construction having a pair of channel regions that have sub-regions doped with indium and surrounded by boron. A pair of transistor constructions are located over the channel regions and are separated by an isolation region. The transistors have gates that are wider than the underlying sub-regions. The invention also includes a semiconductor construction that has transistor constructions with insulative spacers along gate sidewalls. Each transistor construction is between a pair source/drain regions that extend beneath the spacers. A source/drain extension extends the source/drain region farther beneath the transistor constructions on only one side of each of the transistor constructions. The invention also includes methods of forming semiconductor constructions.

Abstract: The invention includes a semiconductor construction having a pair of channel regions that have sub-regions doped with indium and surrounded by boron. A pair of transistor constructions are located over the channel regions and are separated by an isolation region. The transistors have gates that are wider than the underlying subregions. The invention also includes a semiconductor construction that has transistor constructions with insulative spacers along gate sidewalls. Each transistor construction is between a pair source/drain regions that extend beneath the spacers. A source/drain extension extends the source/drain region farther beneath the transistor constructions on only one side of each of the transistor constructions. The invention also includes methods of forming semiconductor constructions.

Abstract: A transistor is protected when a high voltage is applied to a drain, without an increase in the capacitance of the drain. A semiconductor device has a gate electrode on a silicon semiconductor substrate on a gate oxide film, and a pair of N+-type diffusion regions at a surface of a silicon semiconductor substrate on either side of the gate electrode. An N-type diffusion region in the N+-type diffusion region of the drain protrudes to a position deeper in the substrate than the N+-type diffusion region.

Abstract: A first object of the present invention is to provide an insulated gate field effect transistor which realizes reductions in the junction depth and the resistance of source and drain junction regions beneath a gate electrode. Another object is to provide a miniaturized complementary type insulated gate field effect transistor capable of achieving a large current and a high operation speed. In a miniaturized MOS transistor, a low concentration impurity integrated layer comprising In or Ga is provided so as to have a peak in the inside of high concentration shallow source and drain diffusion layer regions. By this arrangement, the shallow source and drain diffusion layers are attracted by the impurity integrated layer, to realize shallower junctions having a high concentration and a rectangular distribution.

Abstract: A new type of partially-depleted SOI MOSFET is described in which a tunneling connection between the gate and the base is introduced. This is achieved by using a gate dielectric whose thickness is below its tunneling threshold. The gate pedestal is made somewhat longer than normal and a region near one end is implanted to be P+ (or N+ in a PMOS device). This allows holes (electrons for PMOS) to tunnel from gate to base. Since the hole current is self limiting, applied voltages greater than 0.7 volts may be used without incurring excessive leakage (as is the case with prior art DTMOS devices). A process for manufacturing the device is also described.

Abstract: In a channel region between the source/drain diffusion layers, impurities of the same conductivity type as the well are doped in an area apart from the diffusion regions. By using as a mask the gate formed in advance, tilted ion implantation in opposite directions is performed to form the diffusion layers and heavily impurity doped region of the same conductivity type as the well in a self-alignment manner relative to the gate.

Abstract: An electrooptical device including a semiconductor device which is formed in a semiconductor layer on an insulating layer in such a manner that floating substrate effects which are essential in a SOI structure is suppressed without reducing the aperture ratio. The thickness of a semiconductor layer in pixel areas is limited to a range equal to or less than 100 nm, p-channel transistors having less floating substrate effects are employed as pixel transistors, and recombination centers are produced by means of implantation of Ar ions, thereby avoiding accumulation of excess carriers, thereby realizing an electrooptical device in which floating substrate effects are suppressed without forming a body contact and which has a high aperture ratio and a low optically induced leakage current.

Abstract: An asymmetric retrograde HALO Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) includes a semiconductor substrate. A gate is formed over the substrate, the gate defining a channel thereunder in the substrate having a source side and a drain side. A retrograde HALO doped area is formed in the source side of the channel using tilted ion implantation. A source and drain are formed in the substrate adjacent to the source and drain sides of the channel. The asymmetrical doping arrangement provides the specified level of off-state leakage current without decreasing saturation drive current and transconductance.

Abstract: A silicon nitride film having a thickness of 3 nm or less is formed on the surfaces of a P-well and N-well, as well as on the upper and side surfaces of a gate electrode, in which the silicon nitride film can be formed, for example, by exposing the surface of the P-well and N-well, and the upper and side surfaces of the gate electrode to a nitrogen-gas-containing plasma using a magnetron RIE apparatus. Then, pocket layers, extension layers and source/drain layers are formed while leaving the silicon nitride film unremoved.

Abstract: Dot-pattern-like impurity regions 104 are artificially and locally formed on a channel forming region 103. The impurity regions 104 restrain the expansion of a drain side depletion layer toward the channel forming region 103 to prevent the short channel effect. The impurity regions 104 allow a channel width W to be substantially fined, and the resultant narrow channel effect releases the lowering of a threshold value voltage which is caused by the short channel effect.