Abstract: A gate structure in a CMOS is fabricated wherein the encapsulation material is self-aligned with the gate conductor and the gate channel. The gate conductor is formed subsequent to the device doping and heat cycles for formulation of the source and drain junction, and is preferably of greater width than the gate.

Abstract: A method for forming N- and P-channel transistors having shallow junctions in an integrated circuit device is described. A semiconductor substrate is provided having active regions separated from one another by isolation regions wherein there is a N-channel active region and a P-channel active region and wherein gate electrodes and associated lightly doped source and drain regions have been formed in each of the active regions. A layer of borosilicate glass is deposited overlying the semiconductor substrate. A photoresist mask is formed over the P-channel active region. The borosilicate glass layer is etched away where it is not covered by the photoresist mask thereby leaving the borosilicate glass layer only overlying the P-channel region. The photoresist mask is removed. A layer of phosphosilicate glass is deposited overlying the semiconductor substrate.

Abstract: A diffused server as a source and a drain. It is formed comprised of a deep first diffused layer and a shallow second diffused layer positioned between the first diffused layer and the channel region. In the second diffused region, a distribution in a depth direction of carriers has a profile in which the concentration is more than 5.times.10.sup.18 cm-.sup.-3 at the peak and is in correspondence with a carrier concentration of the semiconductor substrate at a depth less than 0.04 .mu.m. Since the second diffused layer has a high concentration, the short-channel effect can be suppressed. As the second diffused region, a solid phase diffusion source such as an impurity doped silicate glass is used.

Abstract: A transistor and transistor fabrication method are presented where a sequence of layers are formed and either entirely or partially removed upon sidewall surfaces of a gate conductor. The formation and removal of layers produces a series of laterally spaced surfaces to which various implants can be aligned. Those implants, placed in succession produce a highly graded junction having a relatively smooth doping profile. The multilayer spacer structure comprises a polysilicon spacer interposed between a grown oxide and an etch stop. The polysilicon spacer is formed by an anisotropic etch, and the pre-existing etch stop prevents the anisotropic etch from damaging the source/drain and gate conductor regions beneath the etch stop. Further, the etch stop allows removal of the overlying oxide as well as the entire polysilicon during times when the multi-layer spacer is entirely removed. Removal of the various layers does not damage the underlying substrate due to the presence of the etch stop.

Abstract: A method for fabricating a semiconductor device having a substrate includes the steps of defining a first region and a second region in the substrate, forming a gate insulator over the substrate at each of the first and second regions, forming a gate electrode over the gate insulator and forming impurity regions in the substrate at adjacent sides of the gate electrode in each of the first and second regions, forming a first insulating layer on top and at sides of the gate electrode in the first region, forming a second insulating layer on the first insulating layer at the first region and on the gate electrode of the second region, removing the second insulating layer by selective etching and forming gate sidewalls at the second region, and forming lightly doped drain areas by injecting ions using the gate sidewalls at the second region and the second insulating layer at the first region as masks.

Abstract: A semiconductor device having a controlled drive current strength is produced by varying spacer width to accommodate any variation in gate electrode length from a desired value. After formation of the gate electrode on a substrate, the length is measured and compared to a desired value. Based on any differences between the measured and desired values, the width of spacer is determined in order to counteract the variation in gate electrode length. This results in maintaining the desired channel length after dopant implanting, to provide the desired drive current strength. The present process permits close control over the drive current strength of semiconductor devices and also decreased variation within and between lots and corresponding increases in productivity.

Abstract: A method for forming within an integrated circuit a high areal capacitance planar capacitor, and the high areal capacitance planar capacitor which results from the method. There is first formed upon a semiconductor substrate a first planar capacitor electrode. The first planar capacitor electrode has a first planar capacitor dielectric layer formed thereupon, and the first planar capacitor dielectric layer has a second planar capacitor electrode formed thereupon. Formed then upon the semiconductor substrate is a Pre-Metal Dielectric (PMD) layer which is planarized until the surface of the second planar capacitor electrode is fully exposed. There is formed upon the second planar capacitor electrode a second planar capacitor dielectric layer. Finally, there is formed upon the second planar capacitor dielectric layer a third planar capacitor electrode.

Abstract: A CMOS process with inverse-T gate LDD structure uses liquid phase deposition (LPD) processes to achieve a low thermal budget with only six photoresist-masks in a CMOS device. A first photoresist-mask is used to form field oxide regions. A second photoresist-mask is used to implant a P-well. Before the second photoresist-mask is removed, a first LPD oxide layer is used to cover the N-well. The second photoresist-mask is removed, and the first LPD oxide layer is used as a mask for implanting the N-well. The first LPD oxide layer is removed and a polysilicon layer is deposited on the substrate. A third photoresist-mask is used to etch the polysilicon layer to form gate-structures for the NMOS and PMOS devices. A conformal amorphous Si layer is formed on the gate-structures, followed by forming a fourth photoresist-mask over the N-well. A conformal LPD oxide layer is formed on the conformal polysilicon layer over the P-well. N-LDD regions are then implanted.

Abstract: In the fabrication of an integrated circuit having both N MOSFETs and P MOSFETs in which the respective N-type species and P-type species have substantially different diffusivities, the source implant of the dopant species having a the higher diffusivity is advantageously delayed until a contact masking process step. By delaying the dopant species having the higher diffusivity, depletion of the dopant by subsequent annealing steps is avoided. P MOSFETs formed using a high diffusivity boron implant species in an integrated circuit including both P MOSFETs and N MOSFET are fabricated with no source implant in the source regions during formation of the gate electrodes and sidewall spaces.

Abstract: An isolation gate structure is formed between active areas on a P-type semiconductor substrate. The isolation structure includes a thick gate oxide layer over which is formed a P-doped polycrystalline silicon layer. The polycrystalline silicon layer is electrically connected to the substrate, by buried contact if desired, and can further be electrically connected to a source region formed within the active area. The polycrystalline silicon layer and substrate are connected to ground potential, thus preventing current flow between active areas.

Abstract: N- and P-channel transistor characteristics are independently optimized for CMOS semiconductor devices with design features of 0.25 microns and under. Removable second sidewall spacers are formed on the N-channel transistor gate electrode having first sidewall spacers thereon. Ion implantation is conducted to form N-type moderately/heavily doped implants followed by activation annealing. The second sidewall spacer is then removed from the P-channel transistor leaving first sidewall spacers thereon serving as an ion implantation mask for the P-type lightly doped implants. Subsequently, third sidewall spacers are formed on the P-channel gate electrode having first sidewall spacers thereon followed by ion implantation to form the P-type moderately or heavily doped implants, with subsequent activation annealing. Embodiments enable complete independent control of the channel lengths of the N- and P-channel transistors by varying the width of the first, second and third sidewall spacers.

Abstract: Methods of forming MOS transistors include the steps of forming hot-carrier suppression electrodes on opposing sides of an insulatedgate of a field effect transistor, to reduce hot-carrier degradation parasitics and reduce gate-to-drain overlap capacitance (C.sub.gd). These methods include the steps of forming at least a first hot-carrier suppression electrode between a drain electrode and an insulated gate electrode of a field effect transistor. The hot-carrier suppression electrode reduces the likelihood of hot-carrier degradation parasitics by inhibiting hot electron injection into the gate oxide of the field effect transistor and also reduces the gate-to-drain region capacitance by eliminating the need to establish a fully-overlapped geometry between the transistor's gate and lightly doped drain (LDD) region extension as a way to prevent parasitic injection. According to a preferred embodiment of the present invention, a first electrically insulating layer (e.g., SiO.sub.

Abstract: A method for fabricating a thin film transistor (TFT), including the steps of forming a semiconductor layer on a substrate; forming an insulating oxide layer on the semiconductor layer; forming a polysilicon layer on the insulating layer; etching the polysilicon layer to form a gate electrode having tapered sides; carrying out an oxidation process on exposed surfaces of the gate electrode and the polysilicon layer surrounding the gate electrode resulting in the oxide layer thereby formed being thicker below the bottom edges of the tapered sides of the gate electrode than on other portions of the gate electrode and the surrounding polysilicon layer; and forming impurity regions in the semiconductor layer on opposite sides of the gate electrode to thereby form a transistor. The TFT thereby formed has a tapered gate and reduced OFF current.

Abstract: A metal-oxide-semiconductor field effect transistor (MOSFET) with reduced leakage current includes drain and source regions separated by a channel, a drain terminal over a portion of the drain region, a source terminal over a portion of the source region and a gate terminal opposite the channel. An oxide layer is deposited over the remaining portions of the drain and source regions, as well as on the adjacent vertical sides and top edges of the drain, source and gate terminals. A silicide layer is deposited over the gate terminal between the oxide-covered top edges thereof and over the drain and source terminal up to the oxide-covered top edges thereof. With oxide over the drain source regions instead of silicide, parasitic Schottky diodes are avoided, thereby eliminating leakage current due to such parasitic elements.

Abstract: The present invention is directed to a process for forming a self-aligned raised source/drain MOS device comprising a planarized metal layer, preferably tungsten, overlying a source, a drain, and a gate that is provided on both sides with an insulating spacer to electrically isolate it from the source and drain. The planarized tungsten layer comprises a first portion whose lower surface is in contact with a polysilicon layer of the gate. The lower surface of each of the second and third portions of the tungsten layer is in contact with the source and drain, respectively. The second and third portions are insulated from the first portion by the insulating spacers, and the upper surfaces of all the portions comprise a coplanar surface. Planarization of the deposited metal layer thus provides ohmic contact at substantially the same level to the source, drain, and gate.

Abstract: An IGFET with a gate electrode and metal spacers in a trench is disclosed. The IGFET includes a trench with opposing sidewalls and a bottom surface in a semiconductor substrate, metal spacers adjacent to the sidewalls and the bottom surface, a gate insulator on the bottom surface between the metal spacers, protective insulators on the metal spacers, a gate electrode on the gate insulator and protective insulators, and a source and drain adjacent to the bottom surface.

Abstract: A method of forming a transistor having silicide contacts to the gate and source/drain regions. A semiconductor substrate is provided having spaced field oxide regions and active areas. On the active areas, a gate structure is formed having a gate oxide, gate, and gate insulating layer. In an important step, the gate 18 is laterally etched to remove a first width of the gate. A second dielectric layer 22 composed of oxide is deposited over the sidewalls of the gate, the gate 18 and the substrate 10. The second dielectric layer 22 is etched forming sidewall spacers 24 on the sidewalls of the gate 18, the gate insulating layer 20, and the gate oxide layer. The gate insulating layer 20 is then removed with a selective etch. A metal layer 30 is deposited over the resulting surface. The metal layer 30 is heat treated forming a gate silicide contact 36 on the gate 18 and source and drain silicide contacts 34 on the active areas.

Abstract: A method for fabricating a CMOSFET includes the steps of forming a first well of a first conduction type and a second well of a second conduction type on a substrate of the first conduction type; forming gate electrodes having sides on the first well and the second well; forming semiconductor sidewall spacers of the first conduction type at the sides of the gate electrodes; forming a semiconductor layer of the second conduction type over the first well; implanting impurity ions of the first conduction type into the second well; and annealing the semiconductor substrate to form lightly doped shallow impurity regions of the first conduction type in the first and second wells under the semiconductor sidewall spacers, and heavily doped deep impurity regions of the second conduction type in the first well, and simultaneously activating the impurity ions in the second well to formed heavily doped deep impurity regions of the first conduction type in the second well.

Abstract: A CMIS transistor suitable for device miniaturization, elimination of degradation of operational characteristics by hot carrier effect, and elimination of decrease of threshold voltage caused by short channel effect, includes a laterally spreading N-type diffusion region having an impurity concentration level higher than P-type and N-type wells but lower than source and drain regions, such that the N-type diffusion region extends laterally into a part located immediately below an edge of an insulating gate and has a depth smaller than a depth of the source and drain regions. The device is thereby capable of increasing the width of depletion layer at the bottom of the source and drain regions while maintaining effectiveness as a punch-thorough stopper. Thereby, the junction capacitance at the source and drain regions is reduced and the operational speed of the device improved in the P-channel transistor part in the device.

Abstract: A method for fabricating a metal oxide silicon field effect transistor (MOSFET) wherein a polysilicon layer is deposited over a gate oxide film serving to insulate the gate of the MOSFET from the substrate of the MOSFET. The polysilicon layer serves to prevent the gate oxide film from being etched upon forming a gate electrode using a metal film or metal silicide side walls as a mask. Accordingly, it is possible to prevent a short circuit from occurring between the semiconductor substrate and gate electrode of the MOSFET upon forming the gate electrode.

Abstract: This invention is a process flow involving wordline spacer formation and source/drain implants which mitigates stress-induced damage to the silicon substrate during the post-implant anneal step. The process employs composite wordline spacers having a removable silicon dioxide portion and a non-removable silicon nitride portion. The post-implant anneal step is performed with only the silicon nitride portion of the spacer in place on the wordlines. The thinness of the silicon nitride portion greatly reduces the stress levels experienced by the substrate during the anneal as compared with that experienced by the substrate when thick one-piece silicon nitride spacers are left in place during the anneal.

Abstract: The problem of how to prevent trapping charge during high energy ion implantation, as part of a PLDD, NLDD, PS/D, and NS/D manufacturing process, has been solved through use of a protective cap of photoresist which is applied to the gate prior to the high energy ion implantation. Said protective cap is readily removed after ion implantation.

Abstract: Methods of planarizing one or more layers having an irregular top surface topology in a semiconductor device based on an underlying MOS structure are disclosed. Methods of creating doped wells or regions for the underlying MOS structure are also disclosed, using thick oxide growths on the surface of the substrate to mask implantation of ions into the wells. A technique for creating a pair of adjacent complementary oppositely-doped wells, such as for a CMOS structure, using a thick oxide growths as a mask is also disclosed. One of the methods of planarizing the one or more layers involves depositing, densifying and re-flowing a layer of glass on top of the topological layer. Another method of planarizing the one or more layers involves depositing, densifying and chemical-mechanically polishing the deposited and densified glass, thereby avoiding an additional temperature cycle (i.e., for re-flowing the glass) which would adversely affect underlying diffusions.

Abstract: The method of fabricating a semiconductor device, includes the steps of (a) forming gate oxides on regions separated by device isolation regions, (b) depositing an amorphous silicon or a polysilicon film, (c) depositing a removable space-forming film over the silicon film, (d) patterning the space-forming film and the silicon film into the same shape to form a gate electrode comprising the thus patterned space-forming film and silicon film, (e) depositing a silicon nitride film, (f) etching the silicon nitride film to form a first sidewall around a sidewall of the gate electrode, (g) depositing a silicon oxide film, (h) etching the silicon oxide film to form a second sidewall around and onto the first sidewall, (i) etching the space-forming film with hydrofluoric anhydride for removal so that the silicon film is exposed and the first sidewall remains unremoved, (j) forming source/drain regions, and (k) selectively depositing a refractory metal or metal silicide film on the silicon film and the source/drain re

Abstract: An insulated gate field effect transistor (10) having a reduced gate to drain capacitance and a method of manufacturing the field effect transistor (10). A dopant well (13) is formed in a semiconductor substrate (11) and a drain extension region (25) is formed in the dopant well (13). An oxide layer (26) is formed on the dopant well (13) wherein the oxide layer (26) has a thickness of at least 400 angstroms. A gate structure (61) having a gate shunt portion (32) over a thinned portion of the oxide (26) and a gate extension portion (58) over an unthinned portion of the oxide (26). The thinned portion of the oxide (26) forms a gate oxide of the field effect transistor (10) and the unthinned portion lowers a capacitance of the gate shunt portion (32) of the field effect transistor (10).

Abstract: In a method for manufacturing a salicide MOS device, a gate insulating layer and a polycrystalline silicon gate electrode layer are formed on a monocrystalline silicon substrate. A sidewall insulating layer is formed on a sidewall of the gate electrode layer, and impurities are introduced into the substrate with a mask of the sidewall insulating layer and the gate electrode layer, thus forming impurity diffusion regions in the substrate. Then, an upper portion of the gate electrode layer is etched out. Finally, a metal layer is formed on the entire surface, and a heating operation is carried out, so that metal silicide layers are formed on upper portions of the gate electrodes and the impurity diffusion regions. In an alternative embodiment, the gate further comprises an intervening metal nitride layer.

Abstract: An MOS transistor for use in an integrated circuit, particularly CMOS integrated circuits, is fabricated with a self-aligning contact and interconnect structure which allows for higher packing density. Self-aligning source and drain contacts overlap the gate but are prevented from short circuiting to the gate by oxide insulation between the source/drain contacts and the gate, and a layer of silicon nitride above the gate. Contacts to the gate are made on top of the gate over the active region of the transistor because the source and drain regions are protected by a hardened layer of photoresist during etching of insulation to expose the gate contact. Source, drain and gate contacts are protected by a layer of titanium silicide so that interconnects are not required to completely cover these areas. Low resistance interconnects are formed of titanium silicide encapulated by a thin film of titanium nitride.

Abstract: A process is disclosed for fabricating a CMOS structure with ESD protection. The outside transistors are covered with a protective oxide layer which is so masked as to cover the areas of the respective source and drain regions adjoining the field-oxide regions and the gate regions. The protective oxide layer is then subjected to a heat treatment, after which a siliciding process is carried out.