Abstract: A process for forming a titanium silicide local interconnect between electrodes separated by a dielectric insulator on an integrated circuit. A first layer of titanium is formed on the insulator, and a layer of silicon is formed on the titanium. The silicon layer is masked and etched to form a silicon strip connecting the electrodes, and an overlying second layer of titanium is formed over the silicon strip. The titanium and silicon are heated to form nonsilicidized titanium over a strip of titanium silicide, and the nonsilicidized titanium is removed.

Abstract: A process for the formation of a planar epitaxial cobalt silicide and for the formation of shallow conformal junctions for use in semiconductor processing. A cobalt silicide and titanium nitride bilayer is formed. The titanium nitride layer is chemically removed. Ions with or without a dopant are then implanted into the cobalt silicide layer. During the ion implantation, at least a portion of the cobalt silicide layer is transformed into an amorphous cobalt silicon mixture while the non-amorphous portion remains single crystal. If the ion implantation contains dopants, then after the implantation is completed, both the amorphous and non-amorphous portions of the cobalt silicide layer contain the dopants. The substrate is then annealed in either an ambient comprising a nitrogen gas or in an oxidizing ambient. During the anneal, the amorphous portion of the silicon substrate recrystallizes into a single crystal cobalt silicide layer.

Abstract: A semiconductor device includes a first metal film formed on a semiconductor substrate, a second metal film formed on the first metal film and containing silver as a main component, and a protective film containing a metal element of the first metal film and covering at least the upper surface of the second metal film. The protective film is formed by annealing in an atmosphere containing a predetermined element. That is, the metal element of the first metal film is diffused into the second metal film and reacts with the predetermined element in the atmosphere on the surface of the second metal film, thereby forming the protective film. Aggregation of silver is prevented in the presence of the protective film.

Abstract: A conductive layer in a semiconductor device is protected against chemical attack by a photoresist developer by forming a protective film overlying the conductive layer. The protective film is formed using a chemical reaction that occurs through defects in a passivation layer that was previously formed overlying the conductive layer. The chemical reaction substantially occurs at the surface of the conductive layer and chemically converts portions thereof in forming the protective film. Preferably, the conductive layer is aluminum or an alloy thereof containing copper and/or silicon, and the protective film is aluminum oxide formed on the aluminum layer to protect it from corrosion by tetramethyl ammonium hydroxide (TMAH). The passivation layer is TiN, and the chemical reaction used is oxidation of the aluminum layer through defects in the overlying TiN layer by placing in an ozone asher.

Abstract: A semiconductor wafer is processed so as to inhibit corrosion of aluminum or other metal interconnection lines thereon. The anti-corrosion processing of the wafer takes place after forming a metal layer on a semiconductor wafer, masking the metal layer with resist and reactive ion etching the conductive layer in an evacuated chamber so as to form metal interconnection lines. The semiconductor wafer is then moved under vacuum to a second evacuated chamber, where an oxide is formed on sidewalls of the metal layer by heating the semiconductor wafer while flowing dry oxygen-containing gas. The oxide on the sidewalls of the metal layer prevents corrosion of the metal layer by reactive halogen compounds remaining on the semiconductor wafer after the reactive ion etching step. The resist remaining on the wafer is removed after the semiconductor wafer is removed from the second evacuated chamber.

Abstract: A method is described for fabricating an integrated circuit with polycide gate electrodes in which there is no delamination of the overlying dielectric layer. A polysilicon layer over a gate dielectric is provided on a silicon substrate. A silicide layer is formed over the polysilicon layer using WF.sub.6 and SiH.sub.4 as the reaction gases. The silicide and polysilicon layers are patterned to form polycide gate electrodes. The substrate is annealed initially in an inert gas atmosphere to remove excess fluorine gas, then in an oxygen atmosphere. Lightly doped source and drain ion implants are performed. Spacers are formed on the sidewalls of the polycide gate electrodes. Source/drain ion implants are performed with include fluoride ions. The substrate is degassed in an inert atmosphere to remove the excess fluoride ions. A dielectric layer is deposited over the pattern of polycide gate electrodes and flowed. There is no excess fluorine gas concentration to form a bubble in the dielectric layer.

Abstract: A heterojunction device including a first semiconductive layer on a substrate, a barrier layer on the first layer, a second semiconductive layer on the barrier layer and a multi-layer cap, on the second semiconductive layer. First and second gates positioned on layers of the cap to define first and second transistors, with the cap layers being selected and etched to pin the Fermi level in a first transistor conduction channel in the second semiconductive layer such that the number of carriers in the first conduction channel are substantially less than the number of carriers in surrounding portions of the second semiconductive layer and the Fermi level in a second transistor conduction channel in the first semiconductive layer such that the number of carriers in the second conduction channel are substantially less than the number of carriers in surrounding portions of the first semiconductive layer.

Abstract: Capping a low resistivity metal conductor line or via with a refractory metal allows for effectively using chemical-mechanical polishing techniques because the hard, reduced wear, properties of the refractory metal do not scratch, corrode, or smear during chemical-mechanical polishing. Superior conductive lines and vias are created using a combination of both physical vapor deposition (e.g., evaporation or collimated sputtering) of a low resistivity metal or alloy followed by chemical vapor deposition (CVD) of a refractory metal and subsequent planarization. Altering a ratio of SiH.sub.4 to WF.sub.6 during application of the refractory metal cap by CVD allows for controlled incorporation of silicon into the tungsten capping layer. Collimated sputtering allows for creating a refractory metal liner in an opening in a dielectric which is suitable as a diffusion barrier to copper based metalizations as well as CVD tungsten.

Abstract: A lower wiring layer is formed on an insulating film 12 covering a semiconductor substrate 10. The wiring layer 14 has a laminated structure of a barrier metal layer such as Wsi.sub.2, an Al or Al alloy layer, and a cap metal layer such as WSi.sub.2 formed in this order from the bottom. The cap metal layer is caused to contain conductive material such as Al by using an ion injection method or the like. After forming an insulating film covering the wiring layer, a contact hole is formed in the insulating film by a dry etching process using a resist layer as a mask. The dry etching process uses a fluorine based gas such as CHF.sub.3 as the etching gas. With this etching gas, fluoride such as Al fluoride (AlF.sub.3) is generated to suppress the etching of the cap metal layer.

Abstract: A manufacturing method of semiconductor devices and semiconductor devices isolated by a trench portion. The trench portion is refilled with a Si epitaxial growth layer. The trench has a first insulating layer on its side wall and a second insulating layer formed by the oxidation in the self-alignment manner, as a cap layer, on the top portion of the trench. A semiconductor device formed on the substrate is isolated by the trench. The excessive leakage currents created by the stress between the substrate and the Si epitaxial layer are decreased. The concentration of the field effect at the corner portion of the trench is suppressed by the cap layer. The refilling step can be also made to a trench having the wider opening and another trench having the narrower opening simultaneously and uniformly.

Abstract: A method of manufacturing a semiconductor device is set forth comprising a semiconductor body (1) having a surface (2) adjoined by a semiconductor region (3) and a field oxide region (4) surrounding this region, on which surface (2) is provided a metal layer (13), in which a conductor track (17, 18) is formed, after which an isolating layer of silicon oxide (19) is deposited over the conductor track (17, 18) on the surface (2). According to the invention, before the layer of silicon oxide (19) is provided over the conductor track (17, 18), this track is provided with a top layer (16) of an oxidation-preventing material. By providing this top layer (16), it is avoided that the conductor track (17, 18) covered by silicon oxide (19) has a high electrical resistance or even an electrical interruption.

Abstract: A titanium nitride layer is deposited between the metal titanium layer and the oxide cap of a conventional oxide capped titanium disilicide technology process. This titanium nitride layer is deposited in-situ after a certain thickness of metal titanium has been deposited by bleeding nitrogen gas into the titanium sputter machine. Thereafter the normal oxide cap is deposited over this titanium nitride layer. The normal titanium react process is performed to produce titanium disilicide. After the titanium disilicide has been produced, it is then necessary to strip off the oxide cap. The extra titanium nitride layer makes it is possible to use a wet etch to remove the oxide cap, with the titanium nitride layer serving as a etch stop. In this manner an isotropic wet etch may be employed to remove all of the oxide cap layer. The isotropic wet etch is preferably a 10% buffered HF etch.

Abstract: An ion implantation stopper is formed on a gate electrode extending on a substrate. When ions are implanted into the substrate to form an LDD layer or source and drain regions in the substrate, the stopper functions to prevent the gate electrode from being exposed to ion implantation. The prevention of the exposure of the gate electrode to the ion implantation ensures the prevention of channeling in the gate electrode. The invention includes forming a first protective film on the gate of an NMOS, implanting to form LDD region for the NMOS, implanting to form source and drain regions of a PMOS, forming a second protective film on the gate of the NMOS, implanting to form source and drain regions of the NMOS, the first and second protective films prevent the gate electrode of the NMOS from being exposed to ion implantation during the respective implanting steps so that channeling is prevented from occurring in the gate electrode of the NMOS.

Abstract: The present invention comprises a method of fabricating devices and circuits employing at least one heteroepitaxial layer under strain. The thickness of the heteroepitaxial layer is more than two times the calculated equilibrium critical thickness for an uncapped heteroepitaxial layer upon a crystalline substrate, based on previously known equilibrium theory for the uncapped layer. Subsequent to growth of the heteroepitaxial layer, the structure is processed at temperatures higher than the growth temperature of the heteroepitaxial layer.The strained heteroepitaxial layer (second layer) is epitaxially grown upon the surface of a first, underlaying crystalline layer, creating a heterojunction. Subsequently a third crystalline layer is deposited or grown upon the major exposed surface of the second, strained heteroepitaxial layer. The preferred manner of growth of the third crystalline layer is epitaxial growth.

Abstract: A method is provided for forming isolated regions of oxide of an integrated circuit, and an integrated circuit formed according to the same. A pad oxide layer is formed over the integrated circuit. A nitrogen doped polysilicon layer is formed over the pad oxide layer. A thick nitride layer is then formed over the nitrogen doped polysilicon layer. An opening is formed in the nitride layer and the nitrogen doped polysilicon layer exposing a portion of the pad oxide layer. The nitrogen doped polysilicon layer is annealed encapsulating the polysilicon layer in silicon nitride. A field oxide region is then formed in the opening.

Abstract: A method of fabricating a semiconductor device is disclosed, which can prevent disconnection failures due to corrosion of aluminum-base alloy lines in the semiconductor device. First, an aluminum-base alloy film containing at least one kind of alloying element other than aluminum is formed on an insulating film which covers a semiconductor substrate. Before the surface of the aluminum-base alloy film is cleaned with fuming nitric acid, the surface treatment of the aluminum-base alloy film is performed using a plasma of an oxygen-base gas, to cover fully the surface of the aluminum-base alloy film with passivation film. Next, the given portions of the aluminum-base alloy film are selectively etched to form a line pattern. The surface treatment of the line pattern is performed using a plasma of an oxygen-base gas to cover fully the sides of the line pattern with passive film, before the surface of the line pattern is cleaned with fuming nitric acid.

Abstract: According to this invention, there is provided to a method of manufacturing semiconductor devices including the steps of ion-implanting at least one impurity selected from As, P, Sb, Si, B, Ga, and Al in a wafer prior to a predetermined manufactural process of semiconductor devices in the semiconductor wafer grown by the Czochralski technique, and thereafter annealing the wafer at a temperature of at least 900.degree. C. Nonuniformity of an impurity concentration of the wafer can be improved. The difference in characteristics among the semiconductor devices manufactured in the wafer is decreased, a product yield can be increased, and the quality of the semiconductor devices can be improved.

Abstract: Method for deposit of a p type dopant from a dopant layer into a predetermined region of a III-V semiconductor layer or multiple layers. The p type dopant is deposited in very high concentration in a semiconductor layer adjacent to the predetermined region. A second semiconductor layer, doped with a lower concentration of an n type dopant, is later deposited so that the high concentration p type dopant layer lies between the predetermined region and the n type dopant layer. The p type dopant is diffused into the predetermined region by thermally driven diffusion, which may be carried out at a lower temperature or for a shorter diffusion time interval than with conventional diffusion, and p type dopant diffusion may extend over greater distances.

Abstract: Improved devices with silicon to SiGe alloy heterojunctions are provided for in accordance with the following discoveries. X-ray topography and transmission electron microscopy were used to quantify misfit-dislocation spacings in as-grown Si.sub.1-x Ge.sub.x films formed by Limited Reaction Processing (LRP), which is a chemical vapor deposition technique. These analysis techniques were also used to study dislocation formation during annealing of material grown by both LRP and by molecular beam epitaxy (MBE). The thickness at which misfit dislocations first appear in as-grown material was similar for both growth techniques. The thermal stability of capped and uncapped films was also investigated after rapid thermal annealing in the range of 625.degree. to 1000.degree. C. Significantly fewer misfit dislocations were observed in samples containing an epitaxial silicon cap.

Abstract: Wetting of encapsulated silicon-on-insulator (SOI) films during a zone-melting recrystallization (ZMR) process is enhanced by a high temperature anneal of the SOI structure in a reactive nitrogen-containing ambient to introduce nitrogen atoms to the polysilicon/silicon dioxide cap interface. The technique is not only more effective in present in cap fracture and enhancing crystal quality but is also susceptible to batch processing with noncritical parameters in a highly efficient, uniform manner. Preferably, the cap is exposed to 100% ammonia at 1100.degree. C. for one to three hours followed by a pure oxygen purge for twenty minutes. The ammonia atmosphere is reintroduced at the same temperature for another one to three hour period before ZMR. The process is believed to result in less than a half monolayer of nitrogen at the interior cap interface thereby significantly lowering the contact angle and improving the wetting character of the SOI structure.

Abstract: A low dislocation density semiconductor device includes a first semiconductor layer of a III-V or II-VI semiconductor compound and alloying atoms on a non-metal substrate. The semiconductor compound usually has a large dislocation density. A predetermined position of the alloying atoms in the compound lattice structure can substantially reduce the compound dislocation density. Energy is applied to the alloying atoms so they are at the predetermined positions. The number of alloying atoms causes the semiconductor compound solubility limit to be exceeded. The layer is formed on a substrate of the III-V or II-VI semiconductor, such as gallium arsenide or another semiconductor, such as silicon or on an insulator such as sapphire. In the latter cases, the layer is formed on an intermediate layer having a lattice constant between that of the substrate and semiconductor compound.

Abstract: In situ removal of selected or patterned portions of semiconductor layers is accomplished by induced evaporation enhancement to form patterned buried impurity layers in semiconductor devices, such as heterostructure lasers and array lasers, which function as buried impurity induced layer disordering (BIILD) sources upon subsequent annealing. These layers may be formed to either function as buried impurity induced layer disordering (BIILD) sources or function as a reverse bias junction configuration of confining current to the active region of a laser structure. Their discussion here is limited to the first mentioned function.

Abstract: It has been found that layers which include arsenic and/or zinc can have an adverse effect upon optoelectronic semiconductor devices such as lasers. This is reduced by treatments in which arsenic and zinc are excluded. Preferably the substrate is cooled from reaction temperature in the presence of a mixture of hydrogen and PH.sub.3 (replacing AsH.sub.3 and/or Zn(CH.sub.3).sub.2 used to grow the final layer). Alternatively, devices have a contact layer of heavily p-type gallium indium arsenide are improved by the deposition of a protective layer of indium phosphide. This layer is removed immediately before metalization. Even though the protective layer is not present in the final product it has a beneficial effect.

Abstract: A method of producing a semiconductor laser including deposition a first film as a source of n type impurities on a portion of a semiconductor structure produced by growing at least a p type lower cladding layer, a quantum well active layer, and an n type upper cladding layer successively on a substrate, depositing a second film as a source of p type impurities at least on the surface of the semiconductor structure on both sides of and on the first film and annealing to diffuse p and n type impurities at the same time, thereby disordering portions of the quantum well except for the portion becoming an active region with p type impurities reaching at least the p type lower cladding layer, n type impurities reverting the portions of the n type cladding layer to which p type impurities have diffused to n type, and the n type impurities reaching the n type cladding layer but not reaching the active layer.

Abstract: A silicide layer, to improve conductivity, is formed over a first layer of polycrystalline silicon, followed by a second layer of polycrystalline silicon. This structure is then patterned to form gate regions over active areas. A layer of metal silicide is formed over the entire surface of the chip, and patterned to form local interconnect. Etching of the second metal silicide layer is stopped by the second polycrystalline silicon layer, thereby protecting the first metal silicide layer from damage.

Abstract: Methods for reducing linewidths of Field Effect Transistors (FETs) and making FETs with 0.5 to 0.15 .mu.m effective gate lengths are used separately or in a combined process sequence, that combines enhancement/depletion mode and microwave Metal-Semiconductors FETs (MESFETs) on the same GaAs chip. Photoresist linewidths are used to form dummy or substitutional gates using optical lithography with no deliberate overexposures. The dummy gate may be used as a mask for N+ implantation. The photoresist linewidth is then reduced in its lateral basewidth while preserving its height to basewidth aspect ratio in an isotropic oxygen plasma etch. A nonconformal dielectric film of silicon monoxide is deposited over the photoresist linewidth patterns. Dielectric reverse liftoff of the SiO pattern transfer dielectric provides a self-aligned stencil mask with respect to the N+/N- interfaces. The SiO stencil is also a dielectric spacer with respect to the N+/N- interfaces.

Abstract: A high speed GaAs FET is provided by forming a sandwiched GaAs channel between AlGaAs layers and employing an Si implant to provide channel doping for the GaAs channel. The poor activation efficiency of Si in AlGaAs relative to its activation efficiency in GaAs provides a channel having a higher active dopant concentration than exists in the adjacent sandwiching layers. This tends to enhance conductivity in the channel relative to the sandwiching layers.

Abstract: Films of Hg.sub.1-x Cd.sub.x Te grown at low temperatures by MBE or MOCVD are homogenized by annealing at about 350.degree. C. for 1.25 to 3 hours.

Abstract: A method for selectively etching higher aluminum concentration AlGaAs in the presence of lower aluminum concentration AlGaAs or GaAs, preferably at room temperature. The AlGaAs is first cleaned with a solution of NH.sub.4 OH and rinsed. The AlGaAs is then etched in a solution of HF. If photoresist is used on the AlGaAs, the photoresist may first be baked to increase the adhesion of the photoresist to the AlGaAs and to "toughen" the photoresist to reduce undercutting thereof. Agitation is applied to the AlGaAs or the etchant to assist in the uniform etching of the AlGaAs.

Abstract: A method of passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

Abstract: A low dislocation density semiconductor device includes a first semiconductor layer of a III-V or II-VI semiconductor compound and alloying atoms on a non-metal substrate. The semiconductor compound usually has a large dislocation density. A predetermined position of the alloying atoms in the compound lattice structure can substantially reduce the compound dislocation density. Energy is applied to the alloying atoms so they are at the predetermined positions. The number of alloying atoms causes the semiconductor compound solubility limit to be exceeded. The layer is formed on a substrate of the III-V or II-VI semiconductor, such as gallium arsenide or another semiconductor, such as silicon or on an insulator such as sapphire. In the latter cases, the layer is formed on an intermediate layer having a lattice constant between that of the substrate and semiconductor compound.

Abstract: A semiconductor photodetector, such as a PIN photodiode and an avalanche photodiode, comprising an InP substrate, a first InP layer, a GaInAs or GaInAsP light absorbing layer, and a second InP layer. All of the layers are successively grown by a vapor phase epitaxial process wherein the lattice constant of the GaInAs (GaInAsP) layer is larger than that of the InP layer at room temperature. The photodetector has a low dark current.

Abstract: A semiconductor device has a multilayer comprising a refractory metal silicide and a metal nitride on a silicon layer. The metal nitride prevents the silicon layer from being oxidized so that a good ohmic contact is obtained. A method of manufacturing the semniconductor device comprises steps of forming a polysilicon layer, implanting impurity ions into the polysilicon, removing a self oxidation film from the polysilicon layer, sequentially forming refractory metal and its nitride, patterning, and silicifying the metal. The method provides a semiconductor device having a good ohmic contact, a reduced resistivity of interconnections and high reliability.

Abstract: A process for forming a capping layer over a titanium silicide layer includes forming a layer of polysilicon (16) over a gate-oxide layer (14). A layer of titanium (18) is then formed over the poly layer (16) followed by deposition of a composite layer of tantalum silicide (20). The structure is then patterned and subjected to an annealing process to form a titanium silicide layer (22) covered by the capping layer (20) of tantalum silicide. The tantalum silicide provides a much higher oxidation resistant layer with the underlying titanium silicide providing the desirable conductive properties needed for long runs of interconnects on a semiconductor structure.

Abstract: Multidimensional quantum-well arrays are made by electron-beam lithographic atterning, followed by solid-state diffusion.

Abstract: A method of forming thin epitaxial layers by subjecting a substrate to a high temperature prebake followed by a medium temperature capping seal and a low temperature deposition is disclosed. In a preferred embodiment the epitaxial layer is formed by low pressure chemical vapor deposition of dichlorosilane. The method has been demonstrated to alleviate the increase in autodoping and epitaxial defects normally associated with lowering the deposition temperature.

Abstract: Sealing the backside of a semiconductor wafer prevents evaporation of the dopant (typically boron) when an epitaxial layer is grown on the front (active) side, thereby preventing autodoping of the epitaxial layer with excess dopant. The present technique deposits an oxide layer during the ramp-up of the furnace that also deposits the nitride cap, thereby avoiding an extra process step. It also avoids the higher temperatures required for the prior-art technique of growing the oxide layer, resulting in lower oxygen precipitation due to the capping process and a greater yield of usable wafers.

Abstract: A plasma and heating treatment is carried out to reduce the density of charge carrier traps adjacent the interface of an insulating layer of a thermally grown silicon dioxide and a semiconductor body. During this plasma and heating treatment, the device is covered with an additional layer of silicon containing hydrogen, such as silane, for example, and this additional layer protects the insulating layer from direct bombardment of the plasma. During and/or after the plasma treatment, heating of the structure is at about 400.degree. C. or less. After the plasma and heating treatment, the additional layer is removed from at least most parts of the semiconductor device structure.