Abstract: A method of fabricating a flash memory integrated circuit is described. In an embodiment of the present invention a dielectric filled trench isolation region is formed in a silicon substrate. The dielectric filled trench isolation region isolates a first portion of the silicon substrate from a second portion of the silicon substrate. A portion of the dielectric in the trench is then removed to reveal a portion of the silicon substrate in the trench between the first and second portions of the silicon substrate. Ions are then implanted to form a first source region in the first portion of the silicon substrate and to form a second source region in the second portion of the silicon substrate and to form a doped region in the revealed silicon substrate in the trench wherein the doped region in the trench extends from the first doped source region to the second doped source region.

Abstract: A semiconductor device includes a source region 4, a channel region 8, a drain region 5 and a gate electrode which is patterned so that its side wall is tapered to be more narrow toward the top. A drift region 22 is formed between the channel region 8 and drain region 5 so as to be shallow below the gate electrode 7A (first N− layer 22A) and deep in the vicinity of the drain region 5 (second N− layer 22B). This configuration contributes to boosting the withstand voltage and reducing the “on” resistance of the semiconductor device.

Abstract: The present invention employs a scanned atomic force probe to physical incorporate impurity atoms (dopant or bandgap) into a semiconductor substrate so that the impurity atoms have high resolution and improved placement. Specifically, the method of the present invention comprising a step of physically contacting a semiconductor surface having a layer of a dopant/bandgap source material thereon such that upon said physical contact impurity atoms from the dopant/bandgap source material are driven into the semiconductor substrate.

Abstract: A technique for forming a film of material from a donor substrate. The technique has a step of introducing energetic particles in a selected patterned manner through a surface of a donor substrate having devices to a selected depth underneath the surface, where the particles have a relatively high concentration to define a donor substrate material above the selected depth and the particles for a pattern at the selected depth. An energy source is directed to a selected region of the donor substrate to initiate a controlled cleaving action of the substrate at the selected depth, whereupon the cleaving action provides an expanding cleave front to free the donor material from a remaining portion of the donor substrate.

Abstract: A method for forming a retrograde impurity profile in a semiconducting substrate is provided. The method comprises forming a sacrificial layer having a thickness in the range of about 10 Å to about 150 Å on the surface of a semiconducting substrate. Thereafter, an ion implantation process is performed wherein dopant impurity ions are directed through the sacrificial layer and into the semiconducting substrate under conditions effective to form a retrograde impurity profile in the semiconducting substrate.

Abstract: A semiconductor device with improved short channel characteristics is formed with a buried amorphous region comprising a retrograde impurity region having the impurity concentration peak of the semiconductor substrate. The buried amorphous region, formed below the channel region, suppresses diffusion of displaced atoms and holes from the source/drain regions and reduces the resistance against latch-up phenomenon, thereby improving short channel characteristics.

Abstract: A process is set forth for providing a self-aligned, vertical bipolar transistor. A controlled technique is provided for providing the base and emitter features of the transistor with appropriate dimensions and properties to be useful in high frequency microwave applications. A microwave transistor is provided by this technique.

Abstract: A method for making an SOI semiconductor device including a silicon substrate includes implanting oxide and Nitrogen into the substrate and then annealing to drive Oxygen and Nitrogen through and below the buried oxide layer. The implanted species interact with the Silicon matrix of the substrate to establish field isolation areas that extend deeper than the buried oxide layer of the SOI device, to ensure adequate component isolation.

Abstract: An object is to provide a semiconductor substrate processing method and a semiconductor substrate that prevent formation of particles from the edge part of the substrate. Silicon ions are implanted into the edge part of an SOI substrate (10) in the direction of radiuses of the SOI substrate (10) to bring a buried oxide film (2) in the edge part of the SOI substrate (10) into a silicon-rich state. Thus an SOI substrate (100) is provided, where the buried oxide film (2) has substantially been eliminated in the edge part.

Abstract: The triple-well according to the present invention reduces a photo process forming a well isolation region which is used in a method for forming a prior well. That is, two times of photo processes are reduced to be one time, thereby simplifying a method for forming a triple-well of the DRAM device and reducing time and expenditure.

Abstract: Process for the manufacturing of a DMOS-technology transistor, providing for forming, over a semiconductor material layer of a first conductivity type, an insulated gate electrode, introducing in said semiconductor material layer a first dopant of a second conductivity type for forming at least one body region of a second conductivity type extending under the insulated gate electrode, and introducing in said at least one body region a second dopant of the first conductivity type for forming, inside said body region, at least one source region of the first conductivity type, said body region and said source region defining, under the insulated gate electrode, a channel region for the DMOS transistor, wherein said first dopant is aluminum. After the introduction of said first dopant and said second dopant, a single thermal diffusion process for simultaneously diffusing the first dopant and the second dopant is provided.

Abstract: There is provided a method of fabricating a silicon-on-insulator substrate, including the steps of (a) forming a silicon substrate at a surface thereof with an oxygen-containing region containing oxygen at such a concentration that oxygen is not precipitated in the oxygen-containing region in later mentioned heat treatment, (b) forming a silicon oxide film at a surface of the silicon substrate, (c) implanting hydrogen ions into the silicon substrate through the silicon oxide film, (d) overlapping the silicon substrate and a support substrate each other so that the silicon oxide film makes contact with the support substrate, and (e) applying heat treatment to the thus overlapped silicon substrate and support substrate to thereby separate the silicon substrate into two pieces at a region into which the hydrogen ions have been implanted, one of the two pieces remaining on the silicon oxide film as a silicon-on-insulator active layer.

Abstract: A method is provided for forming buried source line in semiconductor devices. It is known in the art to form buried contacts on the surface of a semiconductor substrate. The present invention discloses a method of fabricating a semiconductor device, particularly a memory cell, having both the source region and the source line buried within the substrate. The source line is formed in a trench in the substrate over the source region. The trench walls are augmented with voltage anti-punch-through protection. The trench also provides the attendant advantages of extended sidewall area, smaller sheet resistance, and yet smaller cell area, therefore, smaller chip size, and faster access time as claimed in the embodiments of this invention. The buried source disclosed here is integrated with source line which is also buried within the substrate.

Abstract: The present invention provides a method for fabricating a trench capacitor, in particular for use in a semiconductor memory cell (100), with an insulation collar (168′; 168″), having the following steps: provision of a substrate (101); formation of a trench (108) in the substrate (101); provision of a first layer (177) on the trench wall; provision of a second layer (178) on the first layer (177) on the trench wall; filling of the trench (108) with a first filling material (152); removal of the first filling material (152) from the upper region of the trench (108) in order to define a collar region; removal of the second layer (178) from the upper region of the trench (108); removal of the first filling material (152) from the lower region of the trench (108); removal of the first layer (177) from the upper region of the trench (108); local oxidation of the upper region of the trench (108) in order to produce the insulation collar (168′; 168″); removal of the first and second layers (1

Abstract: A process for forming a novel substrate material. The process includes providing a substrate, e.g., silicon wafer. The substrate has a stressed layer at a selected depth underneath a surface of the substrate. The stressed layer is at the selected depth to define a substrate material to be removed above the selected depth. The stressed layer comprises a deposited layer and an implanted region. The substrate also comprises a device layer overlying the stressed layer. The process includes forming a plurality of integrated circuit devices on the substrate material. A thermal treatment process at a temperature greater than about 400 degrees Celsius is included in the process of forming the integrated circuit devices. Next, the process includes providing energy to a selected region of the substrate to initiate a controlled cleaving action at the selected depth in the substrate, whereupon the cleaving action is made using a propagating cleave front to free a portion of the material to be removed from the substrate.

Abstract: A semiconductor device having a plurality of transistors connected in series in a semiconductor substrate, the device includes first and second gate electrodes on the semiconductor substrate, a punch-through stop layer in the semiconductor substrate below the first gate electrode at a predetermined depth, and first, second, and third heavily doped impurity regions in the semiconductor substrate at both sides of the first and second gate electrodes.

Abstract: Lifetime of a short-channel NMOS device is increased by modifying distributions of electrically active LDD dopant at boundaries of the device's LDD regions. The LDD dopant distributions are modified by implanting counter-dopants at the boundaries of the LDD regions. Group III counter-dopants such as boron and group IV elements such as silicon alter activation properties of the LDD dopant. The dopant distributions are modified at the device's n-junctions to reduce the maximum electric field displacement at an interface defined by the device's gate and substrate. The dopant distributions can be further modified to shape the n-junctions such that hot carriers are injected away from the gate.

Abstract: A method for forming self-aligned features for semiconductor devices includes the steps of providing a first layer including a reflective material on a surface of the first layer, a second layer formed on the first layer, and a resist layer formed on the second layer, providing radiation through the resist layer and the second layer wherein the radiation is reflected from the reflective material back to the resist layer thereby increasing irradiation of the resist layer over the reflective material and developing the resist layer. A semiconductor device in accordance with the invention includes a first layer with reflective structures therein. A second layer is formed on the first layer, and a patterned resist layer is formed on the second layer.

Abstract: A method of making a MOS transistors in an integrated circuit includes forming a plurality of doped source and drain regions adjacent respective gate structures that include gate dielectrics, gate conductors and spacers. The plurality of doped source and drain regions are formed at different depths, at different doses and with differing dopants. In one embodiment, first doped source and drain regions are formed at a first depth, at a first dose using a first dopant while second doped source and drain regions are formed at a second depth, at a second dose using a second dopant. The first depth is shallower than the second depth so that the first doped source and drain regions serve as sacrificial doped regions that are consumed in a silicidation process when they are converted into a silicide by being combined with a silicidation metal. However, the second doped source and drain regions maintain their doping profiles and dopant levels.

Abstract: A manufacturing method of a dielectric layer for a dynamic random-access-memory capacitor comprising, at first, providing a substrate which has a first conductive layer for the capacitor implanting ions into the first conductive layer. Next, performing a anneal process so as to form the dielectric layer, and then performing a cleaning process with a resolution. Finally, forming a second conductive layer over the first conductive layer. By the manufacturing steps in this invention, it can reduce a thickness of the dielectric layer and increase the dielectric constant, so that charges which can be stored in per unit area of the capacitor without reducing the integration of the DRAM device. Furthermore, it will not reduce the integration of the DARM device.

Abstract: A method of fabricating a buried contact avoids high resistance at a junction by forming a polysilicon layer in a trench. Thus, the current passage is not cut by the trench. The resistance of the trench junction is decreased.

Abstract: A method for making a semiconductor device including a silicon substrate includes implanting oxide into the substrate after gate stack formation and before source/drain dopant implantation. The oxide is implanted such that it defines a concentration profile peak at about 500 .ANG. from the surface of the substrate. Then, Nitrogen is implanted and annealed as appropriate to cause the Nitrogen to agglomerate along the peak of the oxide concentration. The Nitrogen agglomeration establishes the boundary of shallow junction regions and minimal overlap regions in the substrate. Next, the source/drain dopant is implanted and activated, with the dopant essentially being constrained by the Nitrogen to remain concentrated in the shallow junction and minimal overlap regions, thereby minimizing junction capacitance and overlap capacitance in the finished device and consequently improving the speed of operation of the device.

Abstract: A method of manufacturing a buried contact in an SRAM includes retaining a portion of the gate oxide layer adjacent to the source/drain region when a buried contact opening is formed. The retained gate oxide layer protects the substrate by acting as a buffer region, thus preventing the over-etching of substrate, which would form a deep trench. Consequently, contact resistance between the buried contact and the source/drain region is lowered, and leakage current at the junction is prevented.

Abstract: It has been pointed out that the avalanche breakdown voltage of a photodetector comprising an avalanche layer formed by selective epitaxial growth considerably fluctuates. A N.sup.+ --Si buried layer and a N--Si epitaxial layer 3 are successively formed on a P--Si substrate. A cavity is formed in the N--Si epitaxial layer, and a SiO.sub.2 layer is grown in the empty space of the cavity. Then, the SiO.sub.2 layer is etched by dry etching, and a SiO.sub.2 layer is left behind on the side wall of the cavity. Next, a P--Si diffusion layer (an avalanche layer) is formed on the N.sup.+ --Si buried layer by P ion implantation. Subsequently, A SiGe/Si layer (an absorption layer) is selectively grown, and a P.sup.+ --Si layer (an electrode layer) is selectively grown thereon.

Abstract: The method of forming buried contacts on a semiconductor substrate is as follows. At first, a gate insulator layer is formed on the substrate. An undoped silicon layer is then formed on the substrate, and a dielectric layer is formed on the undoped silicon layer. Portions of the dielectric layer, of the undoped silicon layer, and of the gate insulator layer are removed to define a buried contact opening. A doping step is carried out to dope the substrate for forming a buried contact region. A doped silicon layer is formed over the substrate. Next, a portion of the doped silicon layer is then removed to leave a silicon connection and a doped silicon sidewall. The dielectric layer is removed and a thermal oxidization is performed to form a thermal oxide layer on the exposed silicon surfaces. A gate region is defined by removing portions of the thermal oxide layer and the undoped silicon layer. The substrate is doped for forming a lightly doped source/drain region.

Abstract: A method of making a semiconductor device includes forming gate electrode over a substrate and a protective layer over the gate electrode. A portion of the protective layer is selectively removed to expose a peripheral region of the gate electrode. A remainder of the protective layer remains disposed over a central region of the gate electrode. An upper portion of the peripheral region of the gate electrode is then removed typically leaving an underlying portion. Often, a dopant material is implanted into the substrate adjacent to and beneath the underlying portion to simultaneously form lightly-doped and heavily-doped regions beneath and adjacent to the underlying portion, respectively. In addition, all or part of the underlying portion may be oxidized to provide a gate electrode with reduced width.

Abstract: A semiconductor device can be formed with active regions disposed in a substrate adjacent to a gate electrode and a doped region, of the same conductivity type as the active regions, embedded beneath the channel region defined by the active regions. In one embodiment, a patterned masking layer having at least one opening is formed over the substrate. A dopant material is implanted into the substrate using the masking layer to form active regions adjacent to the opening and an embedded doped region that is between and spaced apart from the active regions and is deeper in the substrate then the active regions. In addition or alternatively, spacer structures can be formed on the gate electrode by forming a conformal dielectric layer along a bottom surface and at least one sidewall of the opening and forming a gate electrode in the opening over the dielectric layer.

Abstract: The present invention provides a method of forming buried contacts on a semiconductor substrate. The steps are as follows. At first, a gate insulator layer is formed over the substrate. A first silicon layer is then formed over the gate insulator layer. A buried contact opening is defined through the first silicon layer and the gate insulator layer extending down to the substrate. The substrate is then doped with a region under the buried contact opening for forming a buried contact region. A second silicon layer is formed over the substrate and the first silicon layer. A portion of the second silicon layer is then removed to define a gate region and an interconnect. Next, the substrate is doped for forming a second doping region under a region uncovered by the gate region and the interconnect. A thermal oxidation process is performed to oxidize an exposed portion of the first silicon layer and a portion of the second silicon layer at a top surface.

Abstract: A method for fabricating a Read Only Memory, (ROM), cell on a semiconductor substrate with device region and programmable cell region. The method includes the followed step. A plurality of field oxide regions is formed on the semiconductor substrate. A P-well and an N-well are formed in the device region of the semiconductor substrate, a P-well is formed in the programmable cell region of the substrate. A photoresist is formed over the N-well in the device region. Next, a phosphorus ion implantation is performed into the P-well in the device region for anti-punchthrough and into the N-well in the programmable region to form buried channel by using the photoresist layer as implant mask. After removing the photoresisit, a CMOS transistor is formed on the device region, and a NMOS transistor is formed on the programmable cell region.

Abstract: The present invention provides a method for forming self-aligned spacers on the horizontal surfaces while removing spacer material from the vertical surfaces. The preferred method uses a resist that can be made insoluble to developer by the use of an implant. By conformally depositing the resist over a substrate having both vertical and horizontal surfaces, implanting the resist, and developing the resist, the resist is removed from the vertical surfaces while remaining on the horizontal surfaces. Thus, a self-aligned spacer is formed on the horizontal surfaces while the spacer material is removed from the vertical surfaces. This horizontal-surface spacer can then be used in further fabrication. The preferred method can be used in many different processes where there is exists a need to differentially process the vertical and horizontal surfaces of a substrate.

Abstract: A new method of forming an improved buried contact junction is described. A gate silicon oxide layer is provided over the surface of a semiconductor substrate. A polysilicon layer is deposited overlying the gate oxide layer. A hard mask layer is deposited overlying the polysilicon layer. The hard mask and polysilicon layers are etched away where they are not covered by a mask to form a polysilicon gate electrode and interconnection lines having a silicon nitride layer thereover wherein gaps are left between the gate electrode and interconnection lines. A layer of dielectric material is deposited over the substrate to fill the gaps. The had mask layer is removed. Thereafter, the polysilicon layer is etched away where it is not covered by a buried contact mask to form an opening to the semiconductor substrate. Ions are implanted into the semiconductor substrate within the opening to form the buried contact.

Abstract: A method of manufacturing a flash memory structure that also includes the process of forming a shallow trench isolation structure. The method comprises the steps of providing a semiconductor substrate, and then forming a shallow trench isolation structure within the substrate. Thereafter, etching is carried out to form a shallow trench within a portion of the shallow trench isolation structure. The shallow trench is formed where a common source terminal is subsequently formed. Next, metallic material is deposited into the trench to form a buried metallic layer. Then, a stacked gate is formed above the semiconductor substrate. Finally, ions are implanted into the substrate on each side of the stacked gate using the stacked gate itself as a mask to form a source region and a drain region. The source region and the buried metallic layer are connected together to form a common source region.

Abstract: The present invention provides a novel method for fabricating a buried contact extending under the first conductive layer 16 and subjacent first insulating layer 14. A first insulating layer 14 and a first conductive layer are formed over a silicon substrate 10 having isolation structures 12. A photoresist mask 18A having a buried contact opening 20 is formed over the first conductive layer. The first conductive layer 16 and the first insulating layer 14 are etched through the photoresist mask 18A. A width 21 of the photoresist mask 18A adjacent to the buried contact opening 20 is removed using a descum process, thereby forming an expanded opening 20A and an exposed ring 16A of the first conductive layer 16 with subjacent first insulating layer 14.

Abstract: A technique for reducing silicon defect induced transistor failures, such as latch-up, in a CMOS or other integrated circuit structure includes fabricating the integrated circuit structure on a substrate and implanting a buried layer beneath a surface of the integrated circuit. The buried layer implant is the final implanting step during fabrication of the integrated circuit structure. In another technique, fabricating the integrated circuit structure includes performing multiple sequential processes some of which are performed at elevated temperatures above about 500.degree. C. A buried layer is implanted beneath a surface of the integrated circuit. After implanting the buried layer, the substrate is subjected to a fabrication process at an elevated temperature above about 800.degree. C. only once. Propagation of defects, such as in-the-range defects or ion enhanced stacking faults, from the buried layer to other device layers during the fabrication process is reduced.

Abstract: A integrated circuit transistor that has a high nitrogen concentration in the channel region and a method of making same are provided. A sacrificial oxide layer integrated with a nitrogen bearing species is grown on the substrate. A portion of the nitrogen bearing species diffuses into the substrate to form a nitrogen doped region. Nitrogen is implanted through the first oxide layer to increase the peak concentration of nitrogen in the nitrogen doped region. The sacrificial oxide layer is removed and a very thin gate oxide layer is formed. A gate, a source, and a drain are formed. The result is an integrated circuit transistor with a very thin gate oxide layer and a high peak concentration of nitrogen substantially at the Si--SiO.sub.2 interface.

Abstract: A semiconductor device and method of fabrication for such device in which a P- epitaxial layer is positioned above a P++ substrate. A P++ buried layer implant is positioned within the device between the P++ substrate and the P- epitaxial layer. A connecting p+ implant is placed within the epitaxial layer above the buried p+ blanket layer implant. In one exemplary embodiment, the device includes a shallow P-well with the P+ connecting implant in a position within the epitaxial layer connecting the shallow P-well and the buried P+ blanket implant layer.

Abstract: A process for the manufacturing of integrated circuits provides for forming contacts between a conductive material layer and first doped regions of a semiconductor substrate in a self-aligned manner to edges of an insulating material layer which defines active areas of the integrated circuit wherein the doped regions are formed, and second doped regions of the same conductivity type as the first doped regions under the first doped regions, the second doped regions extending partially under the edges of the insulating material layer to prevent short-circuits between the conductive material layer and the semiconductor substrate. The second doped regions are formed by means of implantation of dopants along directions slanted with respect to an orthogonal direction to a surface of the semiconductor substrate at angles and with an energy sufficiently high to make the dopants penetrate in the semiconductor material deeper than the first doped regions and under the edges of the insulating material layer.

Abstract: A method for manufacturing a buried-channel pMOSFET device that utilizes a plasma doping technique to form a very shallow P-type channel layer on the top surface of a sub-micron buried-channel pMOSFET. The buried-channel pMOSFET device formed by the method has a higher current drivability and a higher anti-punchthrough resistance.

Abstract: A technique for forming a film of material (12) from a donor substrate (10). The technique has a step of forming a stressed region in a selected manner at a selected depth (20) underneath the surface. An energy source such as pressurized fluid is directed to a selected region of the donor substrate to initiate a controlled cleaving action of the substrate (10) at the selected depth (20), whereupon the cleaving action provides an expanding cleave front to free the donor material from a remaining portion of the donor substrate.

Abstract: A method of fabricating a junction-isolated semiconductor device is provided which includes the following steps. Within a first P-type buried region second N-type buried regions are formed. Over the first and second buried regions, an N-type epitaxial layer defining a surface of the device is grown. In the epitaxial layer, P-type isolation regions extending from the surface down to and in electric continuity with the first buried region and defining, with the first buried region, N-type wells incorporating the second buried regions is formed. And, P-type annular border regions in the epitaxial layer and to the side of the isolation regions are formed. The steps of forming isolation regions and annular border regions semiconducting regions being performed in a single step of selectively introducing doping ions.

Abstract: A method for forming field oxide isolation regions using oxygen implantation is described. An oxidation resistant layer such as silicon nitride is formed on a silicon substrate, and acts as an oxidation mask. An opening is then formed in the nitride layer, where field oxide is desired. In one embodiment of the invention, oxygen is implanted into this opening, followed by thermal oxidation. In a second embodiment of the invention, the opening is thermally oxidized, followed by a deep oxygen implant and anneal. Encroachment of the field oxide under the nitride layer is decreased, resulting in a minimum "birds' beak" length.

Abstract: A method of manufacturing the buried contact window of an SRAM cell. The method includes the steps of first providing a first conductive type substrate that has an isolating structure and a gate thereon. The gate comprises a gate oxide layer, a polysilicon layer and a sacrificial layer. Next, a heavily doped region of a second conductive type is formed in the substrate between the device isolating structure and the gate terminal. The heavily doped region acts as a buried contact window. Thereafter, a metal silicide layer is formed over the heavily doped region so that the two are electrically coupled. Next, the sacrificial layer is removed, and then a conductive layer that includes a polysilicon layer and a tungsten silicide layer is formed over the substrate. Subsequently, the conductive layer is patterned to form a conductive line layer and a gate stack.

Abstract: A method is provided for use in a semiconductor fabrication process to form buried diffusion junctions in conjunction with shallow-trench isolation (STI) structures in a semiconductor device. This method features beak-like oxide layers formed to serve as a mask prior to the forming of the STI structures, which can prevent the subsequently formed buried diffusion junctions from being broken up during the process for forming the STI structures. Moreover, sidewall-spacer structures are formed on the sidewalls of a silicon nitride layer used as a mask in the ion-implantation process. This can prevent short-circuits between the buried diffusion junctions when the doped areas are annealed to be transformed into the desired buried diffusion junctions.

Abstract: A technique for forming a film of material (12) from a donor substrate (10). The technique has a step of introducing energetic particles (22) through a surface of a donor substrate (10) to a selected depth (20) underneath the surface, where the particles have a relatively high concentration to define a donor substrate material (12) above the selected depth. An energy source is directed to a selected region of the donor substrate to initiate a controlled cleaving action of the substrate (10) at the selected depth (20), whereupon the cleaving action provides an expanding cleave front to free the donor material from a remaining portion of the donor substrate.

Abstract: The present invention provide a method for forming a triple well. The triple well includes an n-well, a first p-well surrounded with the n-well and a second p-well apart from the first p-well and adjacent to the n-well. According to the present invention, only one conductivity type of impurities are implanted in each well. Therefore, it is possible to prevent the decrease of the carrier mobility and increase of the leakage current.

Abstract: A fabrication process and transistor are described in which a transistor having decreased susceptibility to punchthrough and increased resistance to impurity diffusion is formed. One or more argon doped silicon epitaxial layers are formed superjacent a semiconductor substrate. In a preferred dual layer embodiment, a first argon doped silicon epilayer is grown over a substrate, and a second argon doped epilayer, preferably having an argon concentration less than that in the first epilayer, is formed over the first epilayer. A transistor is formed in an active region of a well having a channel laterally bounded by source/drain regions located exclusively in the second epilayer. The lighter argon doping of the second epilayer accommodates current flow in the channel while acting as a barrier to impurity outdiffusion and inhibiting punchthrough. The more heavily doped first epilayer serves primarily as a barrier to outdiffision of impurities from the bulk substrate.

Abstract: A method is described for forming trench isolation for integrated circuits on silicon wafers by selectively doping the trench regions by ion implantation and then etching these areas with a wet chemical etch. A dopant such as boron, is implanted in a sequence of energies and doses to provide a desired trench profile of heavily doped silicon. The implanted silicon etches far more rapidly than the surrounding silicon and is readily etched out forming a trench. The concentration of dopant diminishes rapidly in the periphery of the implanted region. As the etch front approaches the periphery, the silicon etch rate, likewise diminishes and the etch can be quenched to leave a uniform surface layer of enhanced boron concentration which lines the resultant trench to form an effective channel stop. Wet etched trenches provide advantages over trenches formed by RIE including smooth rounded trench profiles which reduce stress. In addition, trenches having widths below 0.

Abstract: Phosphorous ion is implanted into an SOI substrate under the conditions that the concentration is maximized in the upper silicon layer of the SOI substrate so as to forming a heavily-doped damaged layer, and the heavily-doped damaged layer is partially cured through a lamp annealing so as to concurrently form a heavily-doped buried layer and a gettering site layer.

Abstract: A silicon on insulator (SOI) process is disclosed which includes the steps of forming an etch stop layer in a starting wafer, forming an insulating layer on the etch stop layer, bonding this wafer to a handle wafer, thinning the start wafer down to the etch stop and then recovering a device layer from the etch stop layer by outgassing dopants from the etch stop layer.

Abstract: A technique for forming a film of material (12) from a donor substrate (10). The technique has a step of introducing energetic particles (22) in a selected manner through a surface of a donor substrate (10) to a selected depth (20) underneath the surface, where the particles have a relatively high concentration to define a donor substrate material (12) above the selected depth and the particles for a pattern at the selected depth. An energy source is directed to a selected region of the donor substrate to initiate a controlled cleaving action of the substrate (10) at the selected depth (20), whereupon the cleaving action provides an expanding cleave front to free the donor material from a remaining portion of the donor substrate.