Abstract: A technique is presented which provides for a selective pre-amorphization of source/drain regions of a transistor while preventing pre-amorphization of a gate electrode of the transistor. Illustrative embodiments include the formation of a pre-amorphization implant blocking material over the gate electrode. Further illustrative embodiments include inducing a strain in a channel region by use of various stressors.

Abstract: The present invention generally provides an absorber layer using carbon based materials with increased and stabled thermal absorption coefficient and economical methods to produce such an absorber layer. One embodiment of the present invention provides a method for processing a substrate comprising depositing an absorber layer on a top surface of the substrate, wherein the substrate is maintained under a first temperature, annealing the substrate in a thermal processing chamber, wherein the substrate is heated to a second temperature, and the second temperature is higher than the first temperature, and removing the absorber layer from the substrate.

Abstract: A method for manufacturing SOI wafers is provided which allows the obtaining of a thin SOI layer having uniform in-plane thickness. In this manufacturing method, an oxygen ion implanted layer is first formed on an active layer wafer. This is then laminated to a base wafer with a embedded oxide film interposed therebetween. The active layer wafer side of the laminated wafer is then ground to remove a portion thereof. The remaining surface side of the active layer wafer is removed by polishing or KOH etching to expose the oxygen ion implanted layer. Oxygen ions are implanted to a uniform depth within the plane of the oxygen ion implanted layer in this oxygen ion implanted layer. Subsequently, oxidizing treatment is carried out to form an oxide film on the exposed surface of the oxygen ion implanted layer. Moreover, this oxide film is removed together with the oxygen ion implanted layer by an HF solution. The remaining portion of the active layer wafer serves as a thin SOI layer.

Abstract: By introducing a atomic species, such as carbon, fluorine and the like, into the drain and source regions, as well as in the body region, the junction leakage of SOI transistors may be significantly increased, thereby providing an enhanced leakage path for accumulated minority charge carriers. Consequently, fluctuations of the body potential may be significantly reduced, thereby improving the overall performance of advanced SOI devices. In particular embodiments, the mechanism may be selectively applied to threshold voltage sensitive device areas, such as static RAM areas.

Abstract: A method for manufacturing an SOI substrate is provided in which adhesiveness between a single crystal semiconductor substrate and a semiconductor substrate is improved; bonding defects are reduced; and sufficient bonding strength is provided in a bonding step and also in a process of manufacturing a semiconductor device. An insulating film including halogen is formed on a single crystal semiconductor substrate side in which an embrittlement layer is formed. The insulating film including halogen undergoes a plasma treatment. The insulating film including halogen and a face of a semiconductor substrate are bonded so as to face each other. A thermal treatment is performed to split the single crystal semiconductor substrate along the embrittlement layer, thereby separating the single crystal semiconductor substrate into a single crystal semiconductor substrate and the semiconductor substrate to which a single crystal semiconductor layer is bonded.

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: A semiconductor device includes a plurality of channel structures on a semiconductor substrate. A bit line groove having opposing sidewalls is defined between sidewalls of adjacent ones of the plurality of channel structures.

Abstract: A semiconductor device comprises a field-effect transistor arranged in a semiconductor substrate, which transistor has a gate electrode, source/drain impurity diffusion regions, and carbon layers surrounding the source/drain impurity diffusion regions. Each of the carbon layers is provided at an associated of the source/drain impurity diffusion regions and positioned so as to be offset from the front edge of a source/drain extension in direction away from the gate electrode and to surround as profile the associated source/drain impurity diffusion region.

Abstract: In a method for fabricating a semiconductor element in a substrate, micro-cavities are formed in the substrate. Furthermore, doping atoms are implanted into the substrate, whereby crystal defects are produced in the substrate. The substrate is heated, so that at least some of the crystal defects are eliminated using the micro-cavities, and the semiconductor element is formed using the doping atoms.

Abstract: A method of forming a MOS transistor, in which, a co-implantation is performed to implant a carbon co-implant into a source region and a drain region or a halo implanted region to effectively prevent dopants from over diffusion in the source region and the drain region or the halo implanted region, for obtaining a good junction profile and improving short channel effect, and the carbon co-implant is from a precursor comprising CO or CO2.

Abstract: By introducing additional strain-inducing mechanisms on the basis of stress memorization techniques, the performance of NMOS transistors may be significantly increased, thereby reducing the imbalance between PMOS transistors and NMOS transistors. By amorphizing and re-crystallizing the respective material in the presence of a mask layer at various stages of the manufacturing process, a drive current improvement of up to approximately 27% has been observed, with the potential for further performance gain.

Abstract: A process for producing an SOI substrate includes the steps of forming an oxide film on at least the front surface of a first silicon substrate, implanting hydrogen ion from the surface of the first silicon substrate and thereby forming an ion implantation area in the inside of the first silicon substrate, laminating a second silicon substrate onto the first silicon substrate via the oxide film and thereby forming a laminated body of the first silicon substrate and the second silicon substrate bonded with each other, and heating the laminated body at a predetermined temperature and thereby separating the first silicon substrate at the ion implantation area and thereby obtaining an SOI substrate wherein a thin film SOI layer is formed on the second silicon substrate via the oxide film.

Abstract: A method of making a transistor device having silicided source/drain is provided. A gate electrode is formed on a substrate with a gate dielectric layer therebetween. A spacer is formed on sidewalls of the gate electrode. A source/drain is implanted into the substrate. A pre-amorphization implant (PAI) is performed to form an amorphized layer on the source/drain. A post-PAI annealing process is performed to repair defects formed during the PAI process. A metal silicide layer is then formed from the amorphized layer.

Abstract: A composite dielectric layer including a nitride layer over an oxide layer serves the dual function of acting as an SMT (stress memorization technique) film while an annealing operation is carried out and then remains partially intact as it is patterned to further serve as an RPO film during a subsequent silicidation process. The need to form and remove two separate dielectric material layers is obviated. The nitride layer protects the oxide layer to alleviate oxide damage during a pre-silicidation PAI (pre-amorphization implant) process thereby preventing oxide attack during a subsequent HF dip operation and preventing nickel silicide spiking through the attacked oxide layer during silicidation.

Abstract: A method for semiconductor processing is provided, wherein a removal of one or more layers is aided by structurally weakening the one or more layers via ion implantation. A semiconductor substrate is provided having one or more primary layers formed thereon, and a secondary layer is formed over the one or more primary layers. One or more ion species are implanted into the secondary layer, therein structurally weakening the secondary layer, and a patterned photoresist layer is formed over the secondary layer. Respective portions of the secondary layer and the one or more primary layers that are not covered by the patterned photoresist layer are removed, and the patterned photoresist layer is further removed. At least another portion of the secondary layer is removed, wherein the structural weakening of the secondary layer increases a removal rate of the at least another portion of the secondary layer.

Abstract: Embodiments of this method improve the results of a chemical mechanical polishing (CMP) process. A surface is implanted with a species, such as, for example, Si, Ge, As, B, P, H, He, Ne, Ar, Kr, Xe, and C. The implant of this species will at least affect dishing, erosion, and polishing rates of the CMP process. The species may be selected in one embodiment to either accelerate or decelerate the CMP process. The dose of the species may be varied over the surface in one particular embodiment.

Abstract: The present invention provides a method of manufacturing a bonded wafer. The method comprises an oxidation step in which an oxide film is formed on at least one surface of a base wafer, a bonding step in which the base wafer on which the oxide film has been formed is bonded to a top wafer to form a bonded wafer, and a thinning step in which the top wafer included in the bonded wafer is thinned. The oxidation step comprises heating the base wafer to a heating temperature ranging from 800 to 1300° C. at a rate of temperature increase ranging from 1 to 300° C./second in an oxidizing atmosphere, and the bonding step is carried out so as to position the oxide film formed in the oxidation step at an interface of the top wafer and the base wafer.

Abstract: Embodiments of the present invention provide a method that cools a substrate to a temperature below 10° C. and then implants ions into the substrate while the temperature of the substrate is below 10° C. The implanting causes damage to a first depth of the substrate to create an amorphized region in the substrate. The method forms a layer of metal on the substrate and heats the substrate until the metal reacts with the substrate and forms a silicide region within the amorphized region of the substrate. The depth of the silicide region is at least as deep as the first depth.

Abstract: A method for improving the quality of a SiC layer by effectively reducing or eliminating the carrier trapping centers in the as-grown SiC crystal. The method includes the steps of: (a) carrying out ion implantation of carbon atoms, silicon atoms, hydrogen atoms, or helium atoms into a shallow surface layer of the SiC crystal layer to introduce carbon interstitials into the surface layer, and (b) growing the SiC layer upward from the edge face of the surface layer into which the carbon interstitials have been introduced, and diffusing out the carbon interstitials that have been introduced into the surface layer from the surface layer into the grown layer and combining the carbon interstitials and point defects to make the electrically active point defects in the grown layer inactive.

Abstract: Some embodiments of the invention relate to manufacturing a semiconductor device with an implantation layer on a semiconductor substrate including a method of manufacturing such an implantation layer, wherein said implantation layer is formed in an implantation step at a predetermined depth of penetration, determined from a top surface of said semiconductor substrate, using a particle beam, by increasing its path distance to a main implantation peak and correspondingly increasing the energy level of said particle beam for producing an undamaged implantation layer having a thickness that is increased significantly compared with the thickness of an implantation layer that would be produced at said predetermined depth of penetration using a particle beam with non-increased path distance and energy level.

Abstract: According to one embodiment, a method for the production of a stop zone in a doped zone of a semiconductor body comprises irradiating the semiconductor body with particle radiation in order to produce defects in a crystal lattice of the semiconductor body. The semiconductor body is exposed to an environment containing dopant atoms, during which dopant atoms are indiffused into the semiconductor body at an elevated temperature.

Abstract: It is an object to provide a method for improving the quality of an SiC layer by effectively reducing or eliminating the carrier trapping centers by high temperature annealing and an SiC semiconductor device fabricated by the method. A method for improving the quality of an SiC layer by eliminating or reducing some carrier trapping centers comprising the steps of: (a) carrying out ion implantation of carbon atoms (C), silicon atoms, hydrogen atoms, or helium atoms into a shallow surface layer (A) of the starting SiC crystal layer (E) to introduce excess carbon interstitials into the implanted surface layer, and (b) heating the layer for making the carbon interstitials (C) to diffuse out from the implanted surface layer (A) into a bulk layer (E) and for making the electrically active point defects in the bulk layer inactive. After the above steps, the surface layer (A) can be etched or mechanically removed. A semiconductor device according to the invention is fabricated by the method.

Abstract: This SOI substrate includes a base substrate which includes a single-crystal semiconductor and an active layer which includes a single-crystal semiconductor and is bonded to the base substrate with an oxide film therebetween. The oxide film is formed only in the active layer. The active layer is formed with a thickness of 10 to 200 nm and a thickness variation throughout the active layer of 1.5 nm or less by etching a surface of the active layer while selectively using only the reactive radicals generated by a plasma etching process.

Abstract: A method of forming a compressive channel layer in a PMOS device and a PMOS device having a compressive channel layer are provided. The method includes (a) forming a buffer oxide layer on a silicon semiconductor substrate having a gate oxide layer and a gate electrode thereon, (b) forming a silicon nitride layer on the buffer oxide layer, (c) implanting impurities into the silicon nitride layer, and (d) etching or patterning the silicon nitride layer and the buffer oxide layer into which impurities are implanted to form gate spacers on sidewalls of the gate electrode.

Abstract: A bonded wafer is produced by comprising a step of implanting oxygen ions from a surface of a wafer for active layer to form an oxygen ion implanted layer at a given position inside the wafer for active layer; a step of bonding the wafer of active layer to a wafer for support substrate directly or through an insulating film; a step of subjecting the resulting bonded wafer to a heat treatment for increasing a bonding strength; a step of removing a portion of the wafer for active layer in the bonded wafer to a given position not exposing the oxygen ion implanted layer by a given method; a step of exposing the entire surface of the oxygen ion implanted layer; and a step of removing the exposed oxygen ion implanted layer to obtain an active layer of a given thickness, wherein the step of exposing the entire surface of the oxygen ion implanted layer is carried out by a dry etching under given conditions.

Abstract: A silicon-on-insulator (SOI) device and structure having locally strained regions in the silicon active layer formed by increasing the thickness of underlying regions of a buried insulating layer separating the silicon active layer from the substrate. The stress transferred from the underlying thickened regions of the insulating layer to the overlying strained regions increases carrier mobility in these confined regions of the active layer. Devices formed in and on the silicon active layer may benefit from the increased carrier mobility in the spaced-apart strained regions.

Abstract: A method for introducing impurities includes a step for forming an amorphous layer at a surface of a semiconductor substrate, and a step for forming a shallow impurity-introducing layer at the semiconductor substrate which has been made amorphous, and an apparatus used therefore. Particularly, the step for forming the amorphous layer is a step for irradiating plasma to the surface of the semiconductor substrate, and the step for forming the shallow impurity-introducing layer is a step for introducing impurities into the surface which has been made amorphous.

Abstract: A method of forming a silicon germanium conduction channel under a gate stack of a semiconductor device, the gate stack being formed on a silicon layer on an insulating layer, the method including growing a silicon germanium layer over said silicon layer and heating the device such that germanium condenses in the silicon layer such that a silicon germanium channel is formed between the gate stack and the insulating layer.

Abstract: A process is disclosed which incorporates implantation of a carbon cluster into a substrate to improve the characteristics of transistor junctions when the substrates are doped with Boron and Phosphorous in the manufacturing of PMOS transistor structures in integrated circuits. There are two processes which result from this novel approach: (1) diffusion control for USJ formation; and (2) high dose carbon implantation for stress engineering. Diffusion control for USJ formation is demonstrated in conjunction with a boron or shallow boron cluster implant of the source/drain structures in PMOS. More particularly, first, a cluster carbon ion, such as C16Hx+, is implanted into the source/drain region at approximately the same dose as the subsequent boron implant; followed by a shallow boron, boron cluster, phosphorous or phosphorous cluster ion implant to form the source/drain extensions, preferably using a borohydride cluster, such as B18Hx+ or B10Hx+.

Abstract: A process for manufacturing a silicon-on-insulator substrate comprising a single-crystal silicon substrate in which an oxide layer has been locally buried includes forming a step on the silicon substrate so that a region corresponding to the oxide layer has a greater surface height than other regions; then implanting oxygen ions in the silicon substrate so as to form the oxide layer.

Abstract: Vacancies and dopant ions are introduced near the surface of a semiconductor layer structure. Implanted dopant ions which diffuse by an interstitialcy mechanism have diffusivity greatly reduced, which leads to a very low resistivity doped region and a very shallow junction.

Abstract: A method for introducing impurities includes a step for forming an amorphous layer at a surface of a semiconductor substrate, and a step for forming a shallow impurity-introducing layer at the semiconductor substrate which has been made amorphous, and an apparatus used therefore. Particularly, the step for forming the amorphous layer is a step for irradiating plasma to the surface of the semiconductor substrate, and the step for forming the shallow impurity-introducing layer is a step for introducing impurities into the surface which has been made amorphous.

Abstract: A method of forming an epitaxially grown layer, preferably by providing a region of weakness in a support substrate and transferring a nucleation portion to the support substrate by bonding. A remainder portion of the support substrate is detached at the region of weakness and an epitaxial layer is grown on the nucleation portion. The remainder portion is separated or otherwise removed from the support portion.

Abstract: It is an object to provide a method of manufacturing a semiconductor device capable of forming a MOS transistor of high performance, comprising the steps of forming a gate electrode on a semiconductor substrate via a gate-insulating film (step S1), introducing a impurity into the semiconductor substrate using the gate electrode as a mask (step S7), introducing a diffusion-controlling substance into the semiconductor substrate to control the diffusion of the impurity (step S8), forming a side wall-insulating film on each side surface of the gate electrode (step S9), deeply introducing impurity into the semiconductor substrate using the gate electrode and the side wall-insulating film as masks (step S10), activating the impurity by the annealing treatment using a rapid thermal annealing method (step S11), and further activating the impurity by the millisecond annealing treatment (step S12).

Abstract: An impurity-diffused layer having an extension structure is formed first by implanting Sb ion as an impurity for forming a pocket region; then by implanting N as a diffusion-suppressive substance so as to produce two peaks in the vicinity of the interface with a gate electrode and at an amorphous/crystal interface which serves as an defect interface generated by the impurity in the pocket region; and by carrying out ion implantations for forming an extension region and deep source and drain regions.

Abstract: A method for producing a region of increased doping in an n-doped semiconductor layer which is buried in a semiconductor body of a vertical power transistor and which is arranged between a p-doped body region facing the front side contact of the power transistor and an n-doped substrate facing the rear side contact of the power transistor has the following steps: a) irradiation of at least one part of the surface of the semiconductor body with protons, and b) heat treatment of the semiconductor body.

Abstract: Devices and methods for junction formation in manufacturing a semiconductor device are disclosed. The devices have shallow junction depths far removed from end-of range defects. The method comprises forming an amorphous region in a crystalline semiconductor such as silicon down to a first depth, followed by implantation of a substitutional element such as carbon to a smaller depth than the first depth. The region is then doped with suitable dopants, e.g. phosphorus or boron, and the amorphous layer recrystallized by a thermal process.

Abstract: A method is disclosed for doping a target area of a semiconductor substrate, such as a source or drain region of a transistor, with an electronically active dopant (such as an N-type dopant used to create active areas in NMOS devices, or a P-type dopant used to create active areas in PMOS devices) having a well-controlled placement profile and strong activation. The method comprises placing a carbon-containing diffusion suppressant in the target area at approximately 50% of the concentration of the dopant, and activating the dopant by an approximately 1,040 degree Celsius thermal anneal. In many cases, a thermal anneal at such a high temperature induces excessive diffusion of the dopant out of the target area, but this relative concentration of carbon produces a heretofore unexpected reduction in dopant diffusion during such a high-temperature thermal anneal.

Abstract: Semiconductor structures having a decreased semiconductor junction capacitance of a semiconductor junction within an active semiconductor layer may be fabricated using an ion implantation and thermal annealing method. The ion implantation and thermal annealing method provides for a plurality of voids located completely within the active semiconductor layer proximate to the semiconductor junction located within the active semiconductor layer, absent stressing of the active semiconductor layer.

Abstract: A semiconductor fabrication method. The method includes providing a semiconductor structure which includes (i) a semiconductor layer, (ii) a gate dielectric layer on the semiconductor layer, and (iii) a gate electrode region on the gate dielectric layer. The gate dielectric layer is sandwiched between and electrically insulates the semiconductor layer and the gate electrode region. The semiconductor layer and the gate dielectric layer share a common interfacing surface which defines a reference direction perpendicular to the common interfacing surface and pointing from the semiconductor layer to the gate dielectric layer. Next, a resist layer is formed on the gate dielectric layer and the gate electrode region. Next, a cap portion of the resist layer directly above the gate electrode region in the reference direction is removed without removing any portion of the resist layer not directly above the gate electrode region in the reference direction.

Abstract: A boron ion stream may be used to implant ions, such as boron ions, into the sidewalls of an active area, such as an NFET active area. The boron ion stream has both vertical tilt and horizontal rotation components relative to the sidewalls and/or the silicon device, to provide a better line of sight onto the sidewalls. This may allow components of the silicon device to be moved closer together without unduly reducing the effectiveness of boron doping of NFET active area sidewalls, and provides an improved line of sight of a boron ion stream onto the sidewalls of an NFET active area prior to filling the surrounding trench with STI material.

Abstract: Upon manufacture of a semiconductor device provided with a source region and a drain region formed by activating, through anneal, an n-type first dopant ion-implanted in a p-type device forming area provided in a semiconductor layer formed on an insulator, and a body region, (a) ion implantation of Ar in a boundary region between the source and drain regions to be formed, which corresponds to a region lying in a predeterminate area for forming the body region, and (b) high-temperature anneal for partly recovering crystal defects produced by the ion implantation of the Ar at a temperature higher than the anneal for activation of the first dopant are carried out prior to the ion-implantation of the first dopant.

Abstract: A material for use as part of an internal capacitor within a circuitized substrate includes a polymer (e.g., a cycloaliphatic epoxy or phenoxy based) resin and a quantity of nano-powders of ferroelectric ceramic material (e.g., barium titanate) having a particle size substantially in the range of from about 0.01 microns to about 0.90 microns and a surface area for selected ones of said particles within the range of from about 2.0 to about 20 square meters per gram. A circuitized substrate adapted for using such a material and capacitor therein and a method of making such a substrate are also provided. An electrical assembly (substrate and at least one electrical component) and an information handling system (e.g., personal computer) are also provided.

Abstract: The invention relates to a method of forming a shallow junction. The method (100) comprises forming source/drain extension regions with a non-amorphizing tail implant (105) which is annealed conventionally (spike/RTP) and amorphizing implant which is re-grown epitaxially (SPER) (110). The non-amorphizing tail implant is generally annealed (106) before a doped amorphous layer for SPE is formed (107). SPE provides a high active dopant concentration in a shallow layer. The non-amorphizing tail implant (105) expands the source/drain extension region beyond the range dictated by the SPE-formed layer and keeps the depletion region of the P-N junction away from where end-of-range defects form during the SPE process. Thus, the SPE-formed layer primarily determines the conductivity of the junction while the tail implant determines the location of the depletion region. End-of-range defects form, but are not in a position to cause significant reverse bias leakage.

Abstract: A method for controlling dislocation position in a silicon germanium buffer layer located on a substrate includes irradiating one or more regions of the silicon germanium layer with a dislocation inducing agent and depositing a strained silicon germanium layer on the substrate. The dislocation inducing agent may include ions, electrons, or other radiation source. Dislocations in the silicon germanium layer are located in one or more of the regions. The substrate and strained silicon germanium layer may then be subjected to an annealing process to transform the strained silicon germanium layer into a relaxed state. A top layer of strained silicon or silicon germanium may be deposited on the relaxed silicon germanium layer. Semiconductor-based devices may then be fabricated in the non-damaged regions of the strained silicon or silicon germanium layer. Threading dislocations are confined to damaged areas which may be transformed into SiO2 isolation regions.

Abstract: A method of growing a semiconductor layer structure comprises growing a first semiconductor layer and incorporating hydrogen into the first semiconductor layer. One or more further semiconductor layers are then grown over the first semiconductor layer to form a semiconductor layer structure. A selected portion of the first semiconductor layer is then annealed so as to change the electrical resistance of the selected portion of the first semiconductor layer. The electrical resistance of the one or more further semiconductor layers that have been grown over the first semiconductor layer is not significantly changed by the annealing step. The invention may be used, for example, to create a current aperture in a semiconductor layer within a semiconductor layer structure.

Abstract: A doping method includes implanting first impurity ions into a semiconductor substrate, so as to form a damaged region in the vicinity of a surface of the semiconductor substrate, the first impurity ions not contributing to electric conductivity; implanting second impurity ions into the semiconductor substrate through the damaged region, the second impurity ions having an atomic weight larger than the first impurity ions and contributing to the electric conductivity; and heating the surface of the semiconductor substrate with a light having a pulse width of about 0.1 ms to about 100 ms, so as to activate the second impurity ions.

Abstract: The present invention provides a method for manufacturing a semiconductor device. In one embodiment, the method for manufacturing the semiconductor device includes a method for manufacturing a zener diode, including among others, forming a doped well (240) within a substrate (210) and forming a suppression implant (420) within the substrate (210). The method for manufacturing the zener diode may further include forming a cathode (620) and an anode (520) within the substrate (210), wherein the suppression implant (420) is located proximate the doped well (240) and configured to reduce threading dislocations.

Abstract: A method of forming a surface Ge-containing channel which can be used to fabricate a Ge-based field effect transistor (FET) which can be applied to semiconductor-on-insulator substrates (SOIs) is provided. The disclosed method uses Ge-containing ion beams, such as cluster ion beams, to create a strained Ge-containing rich region at or near a surface of a SOI substrate. The Ge-containing rich region can be present continuously across the entire surface of the semiconductor substrate, or it can be present as a discrete region at a predetermined surface portion of the semiconductor substrate.

Abstract: A method that includes providing a semiconductor substrate having a mask on a surface thereof. The mask includes a first region having no masking elements and a second region having a plurality of masking elements. Each of the plurality of masking elements has a dimension that is equal to a first length, the first length less than twice a diffusion length of a dopant. The method further includes bombarding the semiconductor substrate and masking element with ions of the dopant. The ions form a first impurity concentration in the first region and a second impurity concentration in the second region.