Abstract: A fieldless CMOS image sensor that include a non-LOCOS isolation structure surrounding the photodiode diffusion region of each pixel. The isolation structure is formed by an anti-punchthrough (APT) implant isolation region formed in the substrate around the photodiode diffusion region, and spacer oxide that is formed using a special mask to cover the APT implant region. The APT implant isolation region is self-aligned with the special spacer oxide mask. A width of the isolation structure between two adjacent photodiodes is 0.5 &mgr;m or more. Similarly, LOCOS structures that are used, for example, in the image sensor active circuitry, are separated from the image-sensing (e.g., photodiode) region of each pixel by portions of the isolation structure having a width of 0.5 &mgr;m or more.

Abstract: An on-chip decoupling capacitor cell is disclosed that is compatible with standard CMOS cells. A cell boundary defining the area of the cell includes a first transistor area and a second transistor area. A PMOS transistor having an n-well is formed within the first transistor area. The on-chip decoupling capacitor cell further includes an n-well extension that extends the n-well into the second transistor area, thereby providing a decoupling capacitor cell having reduced leakage compared to a CMOS capacitor cell, and increased capacitance per unit area compare with a traditional PMOS capacitor cell.

Abstract: A crystalline semiconductor having an even surface and a large crystal grain size is formed on an economical glass substrate using a laser crystallizing technology. A series of processes, including forming an insulation film on a glass substrate; forming a semiconductor film in the first layer; crystallizing the semiconductor film in the first layer by irradiating laser light stepwise from weak energy laser light to strong energy laser light; forming a semiconductor film in a second layer having a film thickness thinner than that of the semiconductor film in the first layer; performing laser crystallization of the semiconductor thin film in the second layer by irradiating laser light stepwise from weak energy laser light to strong energy laser light, are continuously performed without exposing the workpiece to the atmosphere.

Abstract: A semiconductor device is presented which is directed to a method of forming embedded DRAM and logic devices, where the DRAM devices are formed in bulk, single crystalline semiconductor regions and logic devices are formed in silicon-on-insulator (“SOI”) regions and where buried, doped glass is used as a mask to form deep trenches for storage in the bulk region. The resulting structure is also disclosed.

Abstract: When an arsenic ion (As+) large in mass is injected, polysilicon films are covered with a fifth resist mask so as to cover an end of the resist mask covering the polysilicon films to form a PMOS forming region. Through this process, a silicide non-forming region is arranged not to overlap with a pn junction to prevent the silicide non-forming region from increasing in resistance.

Abstract: Each of a plurality of repeating units comprises a plurality of memory cells. A second-conductivity-type well is formed in a surface layer of a semiconductor substrate extending over the plurality of the repeating units. In the second-conductivity-type well, first-conductivity-type channel MOS transistors of the plurality of the repeating units are provided. A second-conductivity-type well tap region is formed in one of the memory cells in each repeating unit and in the second-conductivity-type well. In the memory cell provided with the second-conductivity-type well tap region or in the memory cell adjacent thereto, an interlayer connection member is provided. The interlayer connection member is connected to the source region of one of the first-conductivity-type channel MOS transistors and to the corresponding second-conductivity-type well tap region.

Abstract: According to the present invention, contact plugs are formed by a CVD method without deteriorating the properties of the ferroelectric capacitor in a semiconductor device having a fine ferroelectric capacitor. Adhesive film is formed in a contact hole, which exposes an upper electrode of the ferroelectric capacitor after conducting heat treatment in an oxidizing atmosphere, and a W layer is deposited by the CVD method using such TiN adhesive film as a hydrogen barrier and the contact hole is filled.

Abstract: A flat panel display device comprising a thin film semiconductor switching element formed on a surface of a substrate, a display electrode connected with the switching element, a semiconductor layer for auxiliary capacity which is electrically connected with the display electrode, a dielectric layer formed on a surface of the semiconductor layer for auxiliary capacity, and a metal layer formed on a surface of the dielectric layer, wherein the auxiliary capacity is constituted by the semiconductor layer for auxiliary capacity, the dielectric layer, and the metal layer, and the semiconductor layer for auxiliary capacity is implanted all over the surface thereof with a high concentration of impurity ion.

Abstract: A SRAM of complete CMOS type having its memory cell composed of six MISFETs, in which a pair of local wiring lines for connecting the input/output terminals of CMOS inverters are formed of a refractory metal silicide layer formed over a first conducting layer constituting the individual gate electrodes of the drive MISFETs, the transfer MISFETs and the load MISFETs of the memory cell and in which a reference voltage line formed over the local wiring lines is arranged to be superposed over the local wiring lines to form a capacity element. Moreover, the capacity element is formed between the local wiring lines and the first conducting layer by superposing the local wiring lines over the first conducting layer. Moreover the local wiring lines are formed by using resistance lowering means such as silicification. In addition, there are made common the means for lowering the resistance of the gate electrode of the transfer MISFETs and the means for forming the local wiring lines.

Abstract: A bi-layer silicon electrode and its method of fabrication is described. The electrode of the present invention comprises a lower polysilicon film having a random grain microstructure, and an upper polysilicon film having a columnar grain microstructure.

Abstract: A CMOS device and a method for fabricating the same, is disclosed, the device including an insulating film formed on a substrate, first and second sapphire patterns formed on the insulating film at fixed intervals, first and second epitaxial semiconductor layers formed on the first and second sapphire patterns, isolating structures formed at edges of the first and second semiconductor layers, respectively, first and second trenches formed down to predetermined depths from surfaces of the first and second semiconductor layers, sidewall spacer structures formed at both sides of the first and second trenches, a gate insulating film formed on a surface of each of the first and second semiconductor layers between the sidewall spacer structures, first and second gate electrodes formed in the first and second trenches respectively on the gate insulating film, first conductivity type impurity regions formed in the first semiconductor layer on both sides of the first gate electrodes, and second conductivity type impur

Abstract: The present invention discloses a mask ROM which has excellent compatibility with a logic process and improves integration of a memory cell, and a fabrication method thereof. The mask ROM includes: a substrate where a memory cell array region and a segment select region are defined; first and second trenches respectively formed at the outer portion of the memory cell array region and at the outer portion of a buried layer formation region of the segment select region; an element isolating film and an isolating pattern respectively filling up the first and second trenches; a plurality of buried layers aligned on the substrate in a first direction by a predetermined interval, and surrounded by the isolating pattern; and a plurality of gates aligned in a second direction to cross the buried layers in an orthogonal direction.

Abstract: A simple thin film provided on a substrate which supports a semiconductor device structure, over which is formed a dielectric barrier and a composite metal film contact structure. Contacts are formed by creating holes in the dielectric barrier at locations where contact to an upper region of the semiconductor material is required, and then forming a first metal film extending into the holes to contact a top region of the semiconductor structure. A second set of holes are created to expose an underlying opposite polarity region. Surfaces at the second holes are doped and a second metal film is formed to contact the underlying semiconductor region. The metal structure is then scribed to isolate the contacts to the upper and lower semiconductor regions.

Abstract: In a solid state image sensor having micro lenses, the micro lens and a bonding pad electrode are formed on a planarizing layer. Thus, it is no longer necessary to etch the planarizing layer for exposing the bonding pad under the planarizing layer, by use of a photolithography, and therefore, it is possible to avoid dissolution, deform and detachment of the micro lens, which would have otherwise been caused in the prior art by dissolving a photoresist which was used in the photolithography.

Abstract: Various semiconductor device structures that include an inductor or balun can be formed using a semiconductor structure having a monocrystalline silicon substrate, an amorphous oxide material overlying the monocrystalline silicon substrate, a monocrystalline perovskite oxide material overlying the amorphous oxide material; and a monocrystalline compound semiconductor material overlying the monocrystalline perovskite oxide material, and/or other types of material such as metals and non-metals.

Abstract: A static random access memory comprising memory cells each composed of transfer MISFETs controlled by word lines and of a flip-flop circuit made of driver MISFETs and load MISFETs. The top of the load MISFETs is covered with supply voltage lines so that capacitor elements of a stacked structure are formed between the gate electrodes of the load MISFETs and the supply voltage lines.

Abstract: Process for fabrication of semiconductor structures and devices (267, 270) including an intermediate surface cleaning procedure performed to remove metal contaminants in the surface region (262) of a seed film (261) of a monocrystalline compound semiconductor material that is formed overlying a perovskite oxide film (24), which is the source of the contaminants. After removal of the contaminated surface region (262), monocrystalline compound semiconductor material is regrown on the remaining seed film (264) to form a layer (266) having a thickness suitable for forming devices therein.

Abstract: An etching process for manufacturing deep trenches in silicon layers of semiconductor devices and the resulting structures is described. The etching process makes the trenches using a chlorine-based chemical as the primary etchant, while employing various additives to obtain the desired trench surface conditions, geometry, shape, and uniformity. The etching process obtains the trenches in a single step, decreasing the cost and time for manufacturing. In the future, as requirements for IC components (i.e., capacitors and deep isolation trenches) using trenches become more restrictive, the method and structures of present invention could become an integral part of trench technology.

Abstract: There is provided a semiconductor integrated circuit device wherein functional circuit groups are arranged on a chip in a direction spreads, which aims to enhance layout efficiency and to prevent deterioration of element characteristics. A unit wiring region IL1P is constituted outside of a power voltage wiring VCC, a part of a second region BIP and a unit wiring region IL1N is constituted outside of a reference voltage wiring VSS, a part of a second region BIN. Within the second wiring regions BIP and BIN, connection wirings 11, 12A, 13, 14 are wired. These connection wirings connect between units within the logic circuits CIA11, CIR12 or between the logic circuits CIR11, CIR12. There is only arranged an input/output wiring region IOL1 on a first region A1 located between the power voltage wiring VCC1 and the reference voltage wiring VSS1. Since no unit wiring region exists in the first region A1, width of the first region A1 can be laid-out short.

Abstract: A CMOS device formed with a Silicon On Insulator (SOI) technology with reduced Drain Induced Barrier Lowering (DIBL) characteristics and a method for producing the same. The method involves a high energy, high dose implant of boron and phosphorus through the p- and n-wells, into the insulator layer, thereby creating a borophosphosilicate glass (BPSG) structure within the insulation layer underlying the p- and n-wells of the SOI wafer. Backend high temperature processing steps induce diffusion of the boron and phosphorus contained in the BPSG into the p- and n-wells, thereby forming a retrograde dopant profile in the wells. The retrograde dopant profile reduces DIBL and also provides recombination centers adjacent the insulator layer and the active layer to thereby reduce floating body effects for the CMOS device.

Abstract: A solid imaging device including: a semiconductor substrate of a first conductivity type; a layer of a second conductivity type formed on a surface of the semiconductor substrate, the layer at least including a photosensitive portion of the second conductivity type; and a MOS transistor of the second conductivity type coupled to the photosensitive portion, wherein the solid imaging device further includes a layer of the first conductivity type in at least a channel region of the MOS transistor of the second conductivity type, the layer of the first conductivity type having an impurity concentration which is higher than an impurity concentration of the semiconductor substrate, and wherein at least a portion of a boundary of the layer of the second conductivity type is in direct contact with the semiconductor substrate.

Abstract: Single-electron transistors include first and second electrodes and an insulating layer between them on a substrate. The insulating layer has a thickness that defines a spacing between the first and second electrodes. At least one nanoparticle is provided on the insulating layer. Accordingly, a desired spacing between the first and second electrodes may be obtained without the need for high resolution photolithography. An electrically-gated single-electron transistor may be formed, wherein a gate electrode is provided on the at least nanoparticle opposite the insulating layer end. Alternatively, a chemically-gated single-electron transistor may be formed by providing an analyte-specific binding agent on a surface of the at least one nanoparticle. Arrays of single-electron transistors also may be formed on the substrate.

Abstract: An enhanced conductive probe that facilitates the gathering of data and a method of fabricating the probe. The probe includes an amplifier fabricated to define the probe tip. More particularly, the probe structure is defined by an amplifier formed as one of a metal oxide semiconductor (MOS) transistor, a bipolar amplifier, or a metal semiconductor field effect transistor (MESFET), thereby providing for the amplification of the input signal and improved signal to noise ratio during operation of the probe tip.

Abstract: An electronic device on a semiconductor substrate can include first and second field effect transistors on a substrate. In particular, the first field effect transistor includes a first gate dielectric layer having a first nitrogen concentration, and the second field effect transistor includes a second gate dielectric layer having a second nitrogen concentration lower than the first nitrogen concentration. More particularly, the first field effect transistor can be a PMOS transistor, and the second field effect transistor can be an NMOS transistor. Related methods are also discussed.

Abstract: A method of fabricating a dual metal gate CMOS includes forming a gate oxide in a gate region and depositing a place-holder gate in each of a n-well and p-well; removing the place-holder gate and gate oxide; depositing a high-k dielectric in the gate region; depositing a first metal in the gate region of the p-well; depositing a second metal in the gate region of each of the n-well and p-well; and insulating and metallizing the structure. A dual metal gate CMOS of the invention includes PMOS transistor and a NMOS transistor. In the NMOS, a gate includes a high-k cup, a first metal cup formed in the high-k cup, and a second metal gate formed in the first metal cup. In the PMOS, a gate includes a high-k cup and a second metal gate formed in the high-k cup.

Abstract: Providing a semiconductor device with a TFT structure with high reliability

Abstract: In forming a thin film transistor (TFT), a semiconductor region is formed on a glass substrate and then a gate electrode is formed on the semiconductor region through an gate insulating film. After the gate electrode and a gate electrode arrangement extended from the gate electrode is anodized, insulators each having approximately rectangular shape are formed on side surfaces of the gate electrode and the gate electrode arrangement. An interlayer insulator is formed on a whole surface, and then the second layer arrangement is formed on the interlayer insulator. In an overlap portion in which the second layer arrangement overlaps the gate electrode and the gate electrode arrangement, since the insulators is formed, a slope is small.

Abstract: A monolithic sensor including a doped mechanical structure is movably supported by but electrically isolated from a single crystal semiconductor substrate of the sensor through a relatively simple process. The sensor is preferably made from a single crystal silicon substrate using front-side release etch-diffusion. Thick single crystal Si micromechanical devices are combined with a conventional bipolar complimentary metal oxide semiconductor (BiCMOS) integrated circuit process. This merged process allows the integration of Si mechanical resonators as thick as 15 &mgr;m thick or more with any conventional integrated circuit process with the addition of only a single masking step. The process does not require the use of Si on insulator wafers or any type of wafer bonding. The Si resonators are etched in an inductively coupled plasma source which allows deep trenches to be fabricated with high aspect ratios and smooth sidewall surfaces.

Abstract: A method and a device for locally heating a semiconductor wafer having a first region of a first impurity and a second region of a second impurity having a diffusion rate different from that of the first impurity. A field oxide layer, a P well and an N well, gate oxide layers, gate electrodes, an N-type region and a P-type region are formed in sequence on or in a silicon wafer. The wafer is placed into a chamber. Then, a mask, which has a pattern for blocking the radiation from the heat source to the N well of the wafer, is positioned between the heat source and the wafer. The heat source emits radiation for heating the wafer, thereby the donor-type dopant atoms in the N-type region are diffused with a diffusion depth of d2 to form an electrically active region, but the acceptor-type dopant atoms in the P-type region are not diffused. After this step, a mask, which has a pattern for blocking the radiation from the heat source to the P well of the wafer, is positioned between the heat source and the wafer.

Abstract: A semiconductor device comprising a first transistor (40) and a second transistor (100), both formed in a semiconductor substrate (50). The first transistor comprises a gate conductor (56) and a gate insulator (54) separating the gate conductor from a semiconductor material and defining a channel area (66) in the semiconductor material opposite from the gate conductor. The first transistor further comprises a source (S2) comprising a first doped region (581) of a first conductivity type and adjacent the channel area. Further, the first transistor comprises a drain (D2). The drain comprises a first well (641) adjacent the channel area and having a first concentration of the first conductivity type and a first doped region portion and a second doped portion (68). The first doped portion has a second concentration of the first conductivity type. The second concentration is greater than the first concentration and the first doped region portion has a common interface with the first well.

Abstract: To provide a technique required for purifying the interface between an active layer and an insulating film. On a substrate (101), a gate wiring (103) is formed and the surface thereof is covered with a gate oxide film (104). Then, a first insulating film (105a), a second insulating film (105b), a semiconductor film (106) and a protective film (107) are sequentially formed and layered without exposing them to the air. Further, the semiconductor film (106) is irradiated with laser light through the protective film (107). In this way, a TFT may be given good characteristics by completely purifying the interface of the semiconductor film.

Abstract: A method of fabricating a CMOS transistor to construct shallow drain extenders (30) using a replacement gate design. The method involves forming epitaxial layers (30) and (220) the will later function as shallow drain extensions. The etching of the replacement gate (220) and the formation of inner sidewalls (90) serve to define the transistor gate length.

Abstract: A three-dimensional integrated circuit and fabrication process is provided for producing active and passive devices on various levels of the integrated circuit. The present process is particularly suited to interconnecting a source of one transistor to a drain of another to form series-connected transistors often employed in core logic units. A junction of an underlying transistor can be connected to a junction of an overlying transistor, with both transistors separated by an interlevel dielectric. The lower transistor junction is connected to the upper level transistor junction using a plug conductor. The plug conductor and, more specifically, the mutually connected junction, is further coupled to a laterally extended interconnect. The interconnect extends from the mutual connection point of the plug conductor to a substrate of the overlying transistor.

Abstract: A CMOS image sensor fabrication method that is capable of preventing a surface of a metal line from being damaged or contaminated is provided. The formed CMOS image sensor includes: a semiconductor structure, wherein the semiconductor structure includes a unit pixel area and a pad area; a metal line formed on the pad area, wherein a portion of the metal line is exposed; a passivation layer formed on the unit pixel area and on the metal line such that the exposed portion is left exposed; a planarized photoresist formed on a portion of the passivation layer; a micro-lens formed on a portion of the planarized photoresist; and an oxide layer formed on the entire formed structure such that the exposed portion is left exposed.

Abstract: A MOS (Metal Oxide Semiconductor) transistor includes a gate electrode, a drain electrode, and a source electrode. The MOS transistor has an on-state resistance when the MOS transistor is in an ON state. The MOS transistor further includes a specific electrode, wherein the specific electrode connects the source electrode to a power supply section to which a power is supplied. The specific electrode has a resistance substantially identical to the on-state resistance. The specific electrode has a width substantially identical to a width of the gate electrode. The specific electrode and the gate electrode are formed at a same time.

Abstract: A circuit including at least one strained channel, enhancement mode FET, and at least one strained channel, depletion mode FET. The depletion mode FET includes an ion implanted dopant supply. In exemplary embodiments, the FETs are surface channel or buried channel MOSFETS. In another exemplary embodiment, the FETs are interconnected to form an inverter.

Abstract: A photoelectric conversion device has a non-single-crystal semiconductor laminate member formed on a substrate having a conductive surface, and a conductive layer formed on the non-single-crystal semiconductor laminate member. The non-single-crystal semiconductor laminate member has such a structure that a first non-single-crystal semiconductor layer having a P or N first conductivity type, an I-type second non-single-crystal semiconductor layer and a third non-single-crystal semiconductor layer having a second conductivity type opposite the first conductivity type are laminated in this order. The first (or third) non-single-crystal semiconductor layer is disposed on the side on which light is incident, and is P-type. The I-type non-single-crystal semiconductor layer has introduced thereinto a P-type impurity, such as boron which is distributed so that its concentration decreases towards the third (or first) non-single-crystal semiconductor layer in the thickwise direction of the I-type layer.

Abstract: The TFT has a channel-forming region formed of a crystalline semiconductor film obtained by heat-treating and crystallizing an amorphous semiconductor film containing silicon as a main component and germanium in an amount of not smaller than 0.1 atomic % but not larger than 10 atomic % while adding a metal element thereto, wherein not smaller than 20% of the lattice plane {101} has an angle of not larger than 10 degrees with respect to the surface of the semiconductor film, not larger than 3% of the lattice plane {001} has an angle of not larger than 10 degrees with respect to the surface of the semiconductor film, and not larger than 5% of the lattice plane {111} has an angle of not larger than 10 degrees with respect to the surface of the semiconductor film as detected by the electron backscatter diffraction pattern method.

Abstract: A method of forming a MOS device using doped and activated n-type and p-type polysilicon layers includes forming a first doped and activated polysilicon area (either n-type and p-type) on a substrate. An isolation material layer is formed abutting the first activated area. A second doped and activated polysilicon area of opposite conductivity type from the first activated area is formed adjacent to the isolation material layer. The second activated opposite area has a height that does not exceed that of the first doped and activated polysilicon layer. Further processing may be effected to complete the MOS device. The method of the present invention eliminates ion implantation and annealing steps used in previously existing methods.

Abstract: A process for fabricating a highly stable and reliable semiconductor, comprising: coating the surface of an amorphous silicon film with a solution containing a catalyst element capable of accelerating the crystallization of the amorphous silicon film, and heat treating the amorphous silicon film thereafter to crystallize the film.

Abstract: An SRAM cell is arranged in a semiconductor device. A metal oxide semiconductor field effect transistor is arranged in the SRAM cell. An interlayer insulating film is formed on the metal oxide semiconductor field effect transistor. A load resistor conductive layer is formed on the interlayer insulating film. In addition, a wiring conductive layer which connects the gate electrode of the metal oxide semiconductor field effect transistor to the load resistor conductive layer is provided. The resistance of the wiring conductive layer is lower than the resistance of the load resistor conductive layer. A side wall is formed between the load resistor conductive layer and the wiring conductive layer.

Abstract: A method of forming a MOS device using doped and activated n-type and p-type polysilicon layers wherein a first doped and activated polysilicon layer (either n-type and p-type) is patterned on a substrate. An isolation material layer is formed abutting the first doped and activated polysilicon layer in the corners formed at the junction between the first doped and activated polysilicon layer and the substrate. A second doped and activated polysilicon layer (either n-type or p-type) is applied over the first doped and activated polysilicon layer and the isolation material layer. The second doped and activated polysilicon layer is planarized to the height of the first doped and activated polysilicon layer. The first and second doped and activated polysilicon layers are etched to substantially bifurcate the first and second doped and activated polysilicon layers. Further processing steps known in the art are utilized to complete the MOS device.

Abstract: The solution (for example, a nickel acetate solution) containing a metal element such as nickel which accelerates the crystallization of silicon is applied to an amorphous silicon film by spin coating using a mask, to retain nickel in contact with the surface of the amorphous silicon film. Then, heating treatment is performed to crystallize selectively the amorphous silicon film, so that an amorphous region and a crystalline region are formed in the silicon film. In this state, the silicon film is heated to diffuse the metal element from the crystalline region to the amorphous region, thereby decreasing a concentration of the metal element in the crystalline region.

Abstract: A static random access memory comprising memory cells each composed of transfer MISFETs controlled by word lines and of a flip-flop circuit made of driver MISFETs and load MISFETs. The top of the load MISFETs is covered with supply voltage lines so that capacitor elements of a stacked structure are formed between the gate electrodes of the load MISFETs and the supply voltage lines.

Abstract: The present invention describes the use of two semiconductor layers, a thin film (TF) layer and a bulk Si wafer layer, to make high density and high speed merged logic and memory IC chips. The memory cells use three-dimensional (3D) SRAM structures. Two kinds of 3D logic cells are disclosed. 3D form of the differential cascode voltage switch (DCVS) architecture, and a 3D form of the DCVS with pass gate (DCVSPG) logic architecture. A high density “system on chip” architecture is described. The high density is achieved by locating large PMOS transistors in the TF Si layer, and the fast NMOS transistors in a bulk Si wafer layer. A single process sequence to simultaneously make the logic and memory circuits on the IC chip is also described.

Abstract: An SOI MOSFET having improved electrical characteristics includes a low barrier body contact under the source region, and alternatively under the drain region, to facilitate collection and removal of current carriers generated by impact ionization. Fully-depleted and non-fully-depleted SOI MOSFETs can be integrated on the same chip by providing some transistors with thicker source and drain regions with a recessed channel therebetween and by selective channel dopant implant. Accordingly, digital circuitry and analog circuitry can be combined on one substrate. Improved electrostatic discharge protection is provided by fabricating transistors for the protection circuit directly in the supporting substrate by first removing the silicon thin film and underlying insulation barrier.

Abstract: Shallow trench isolation is combined with optional deep trenches that are self-aligned with the shallow trenches, at the corners of the shallow trenches, and have a deep trench width that is controlled by the thickness of a temporary sidewall deposited in the interior of the shallow trench and is limited by the sidewall deposition thickness of the deep trench fill.

Abstract: A semiconductor device which materializes dynamic threshold operation, on the assumption of the application of a bulk semiconductor substrate. The semiconductor substrate has a first conductivity type well region (11), a source region (12) and a drain region (13) of second conductivity type are made in the vicinity of the surface of the first conductivity type of well region (11), a channel region (14) is provided between these regions (12 and 13), a gate insulating film (15) and a gate electrode (16) are stacked in order on the channel region (14), and the gate electrode (16) is connected to the well region (11) through the contact hole (not shown in the figure) of the gate insulating film (15). In this transistor, as compared with a conventional SOI substrate, the resistance of the well region (11) can be lowered to about one-tenth.

Abstract: A thin film transistor includes: an insulating substrate; a semiconductor layer of a polycrystalline silicon formed on the insulating substrate; a gate insulator film formed so as to contact the semiconductor layer; a gate electrode formed so as to contact the gate insulator film; an active layer formed in a region of the semiconductor layer corresponding to the gate electrode; a first semiconductor region which is formed in the semiconductor layer outside of the active layer and which has an impurity concentration of higher than or equal to 1×1018 cm−3 and lower than 1×1020 cm−3; and a second semiconductor region which is formed in the semiconductor layer outside of the first semiconductor region and which has an impurity concentration of higher than that of the first semiconductor region, the second semiconductor region having the same conductive type as that of the first semiconductor region. Thus, it is possible to obtain a reliable thin film transistor having small OFF current.

Abstract: A semiconductor device having a CMOS structure, wherein, in manufacturing a CMOS circuit, an impurity element which imparts p-type conductivity to the active layer of the p-channel type semiconductor device is added before forming the gate insulating film. Then, by applying thermal oxidation treatment to the active layer, the impurity element is subjected to redistribution, and the concentration of the impurity element in the principal surface of the active layer is minimized. The precise control of threshold voltage is enabled by the impurity element that is present in a trace quantity.