Abstract: A method for fabricating a semiconductor device, comprising the steps of: forming an element on a silicon substrate; packaging the element; and annealing the packaged element before its transportation or long-term storage.

Abstract: A method of making a current type active matrix OLED device, includes providing a semiconductor layer, a conductive layer, and an insulator layer therebetween over a substrate, providing an organic light emitting diode over either the semiconductor layer or over the conductive layer for each pixel, and forming a first transistor having a channel region formed in the semiconductor layer and a gate formed in the conductive layer for each pixel for receiving a first current data signal for adjusting the emission brightness in its corresponding pixel. The method also includes forming a second transistor for each pixel for regulating current through the organic light emitting diode in response to the first current wherein each second transistor has a gate formed in the conductive layer and a channel region formed in the semiconductor layer, and annealing particular regions of the semiconductor layer by using a pulsed laser.

Abstract: An aspect of the present invention is a method for forming a plurality of thin-film devices. The method includes coarsely patterning at least one thin-film material on a flexible substrate and forming a plurality of thin-film elements on the flexible substrate with a self-aligned imprint lithography (SAIL) process.

Abstract: A heat spreader, comprised of a plurality of carbon fibers oriented in a plurality of directions, with a carbon or metal matrix material dispersed about the fibers, is described. The carbon fibers facilitate the spreading of heat away from the smaller semiconductor device and up to a larger heat removal device, such as a heat sink.

Abstract: An integrated circuit package includes a semiconductor chip having a passivation layer forming the top surface of the semiconductor chip and a metal pad formed on the passivation layer and a discrete electronic device having a first terminal formed on a first surface and a second terminal formed on a second surface opposite the first surface of the discrete electronic device where the first surface of the discrete electronic device is attached to the metal pad using a conductive adhesive structure. The semiconductor chip and the discrete electronic device are encapsulated in an encapsulation material. An electrical connection is formed between the metal pad and one of a bond pad of the semiconductor chip or a package post of the integrated circuit package. In one embodiment, the metal pad is an aluminum pad and a metal line connects the metal pad to a bond pad of the semiconductor chip.

Abstract: A lead frame comprises a stage for mounting a semiconductor chip thereon, a plurality of leads arranged in the periphery of the stage, and a plurality of lead interconnection members (e.g., dam bars) for interconnecting the leads, wherein a plurality of through holes are formed to penetrate through the lead frame in a thickness direction with respect to the leads or the lead interconnection members so as to allow a plurality of cutting lines to pass therethrough, whereby the leads are subjected to cutting and are made electrically independent of each other. A semiconductor package of a QFN type is produced by enclosing the lead frame within a molded resin, from which the leads are partially exposed to the exterior and are subjected to plating and are then subjected to cutting at the cutting lines.

Abstract: A semiconductor device having reduced self and mutual capacitance of bonded wires is provided by coating the wires with a foamed polymer effectively having a very low dielectric constant. Additional benefits are realized by electrically insulating the wires against short-circuiting, by cushioning the wires with a low modulus sheath, and by protecting chip bond pad metallization TABLE 1 Method of Moments Capacitance Models Wire Dimensions 25 × 25 microns Separation between Wires 63.5 microns Distance to ground ?191 microns Model Dielectric Self capacitance Mutual Capacitance constant of Wire 1 Wire 2 separation Model Dielectric Wire 1 Wire 2- Mutual cap constants self cap self cap pf/cm pf/cm pf/cm Plastic encased 4.0 1.03 0.54 1.57 package Cavity package 4./1.0/4. 0.31 0.12 0.43 Foam sheath 4./1./4./1./4. 0.34 0.16 0.50 wires/molded Wires - no 1.? 0.26 0.13 ?0.39.

Abstract: This disclosure describes a clear overmolding cap for protecting the photonic devices in optoelectronic packages from damage due to handling, module assembly, board assembly, and environmental exposure in field applications. The overmolding of the devices with a clear mold cap or similar material also provides a standoff for optical fibers positioned next to the active facets. The photonic devices are attached to a substrate, which may be flexible that has electronic traces that allow the photonic devices to be connected to an external device such as a semiconductor device. A technique for manufacturing the overmolding cap using a mold die system in combination with a rigid carrier is also disclosed. The rigid carrier is used to maintain the shape of the substrate during the molding process. The proposed method applies to photonic devices used in optoelectronic packages that can serve as transceivers, transmitters, or receivers.

Abstract: A method for balancing molding flow during the assembly of semiconductor packages with defective carrying units includes providing a chip carrier, which includes a number of good carrying units and at least a defective carrying unit. Then, a number of chips are attached to the good carrying units of the chip carrier, and a chip-imitative glue is formed on the defective carrying unit of the chip carrier. Next, a molding compound is formed on the chip carrier via molding to seal the chips and the chip-imitative glue, thereby improving the balance of molding flow.

Abstract: A microelectronic component package includes a plurality of electrical leads which are coupled to a microelectronic component and which have exposed lengths extending outwardly beyond a peripheral edge of an encapsulant. A plurality of terminals may be positioned proximate a terminal face of the encapsulant and these terminals may be electrically coupled to the same leads. This can facilitate connection of the microelectronic component to a substrate using the leads as a conventional leaded package. The terminals, however, can facilitate stacking of the leaded package with one or more additional microelectronic components, e.g., a BGA package.

Abstract: The present invention provides a novel ESD structure for protecting an integrated circuit (IC) from ESD damage and a method of fabricating the ESD structure on a semiconductor substrate. The ESD structure of the present invention has lower trigger voltage and lower capacitance, and takes smaller substrate area than prior art ESD structures. The low trigger voltage is provided by a small N+P diode or a P+N diode which has a PN junction with a much lower breakdown voltage than a PN junction between a N+ (or P+) source/drain region and a P-well (or N-well). All of the diffusion regions in the ESD device of the present invention can be formed using ordinary process steps for fabricating the MOS devices in the IC and does not require extra masking steps in addition to those required to fabricate the IC.

Abstract: A thyristor-based semiconductor memory device may comprise at least a region thereof, e.g., a p-base region, having high ionization energy impurity, such as a dopant. This high ionization energy impurity within a base region may be operable to compensate for a gain-versus-temperature dependence of a constituent bipolar transistor of the thyristor element of a thyristor-based memory device. In particular embodiments, the high ionization energy impurity may include a donor and/or acceptor in silicon.

Abstract: A thin film transistor has a structure capable of decreasing deterioration in Vgs-Ids characteristics. The thin film transistor has a source region composed of an N-type impurity-diffused region, a drain region, and a gate electrode, and a channel region formed directly below the gate electrode. To the source region and the drain region are connected a source electrode and a drain electrode, respectively, through a plurality of contact holes. In the channel region are formed a plurality of P-type impurity-diffused regions at constant intervals.

Abstract: Disclosed are an arrangement and a production method for electrically connecting (20) active semiconductor structures (40) in the monocrystalline silicon layer (12) located on the front face of silicon-on-insulator semiconductor wafers (SOI; 10) to the substrate (13) located on the rear side and additional structures (13a) that are disposed therein. The electric connection is made through the insulator layer (11).

Abstract: Provided is a MOSFET with an ultra short channel length and a method of fabricating the same. The ultra short channel MOSFET has a silicon wire channel region with a three-dimensional structure, and a source/drain junction formed in a silicon conductive layer formed of both sides of the silicon wire channel region. Also, a gate electrode formed on the upper surface of the silicon wire channel region by interposing a gate insulating layer having a high dielectric constant therebetween, and source and drain electrodes connected to the source/drain junction are included. The silicon wire channel region is formed with a triangular or trapezoidal section by taking advantage of different etch rates that depend on the planar orientation of the silicon. The source/drain junction is formed by a solid-state diffusion method.

Abstract: Silicon carbon is used as a diffusion barrier to germanium so that a silicon layer can be subsequently formed without being contaminated with germanium. This is useful in separating silicon layers from silicon germanium layers in situations in which both silicon and silicon germanium are desired to be present on the same semiconductor device such as for providing different materials for optimizing carrier mobility between N and P channel transistors and for a raised source/drain of silicon in the case of a silicon germanium body.

Abstract: A gate dielectric (150) for a gate (160) is formed by thermal oxidation simultaneously with as a dielectric on a surface of another gate (140). The dielectric thickness on the other gate is controlled by the dopant concentration in the other gate. The gates may be gates of different MOS transistors, or a select gate and a floating gate of a memory cell. Other features are also provided.

Abstract: The concept of the present invention describes a semiconductor device with a junction 504 between a lightly doped region 501 and a heavily doped region 502, wherein the junction has an elongated portion 504a and curved portions 504b. The doping concentration of the lightly doped region is configured so that it exhibits higher resistivity in the proximity 510 of the curved portion by an amount suitable to lower the electric field strength during device operation and thus to offset the increased field strength caused by the curved portion. As a consequence, the device breakdown voltage in the curved junction portion becomes equal to or greater than the breakdown voltage in the linear portion.

Abstract: Methods of fabricating semiconductor devices are provided. Transistors are provided on a semiconductor substrate. A first interlayer insulating layer is provided on the transistors. A second interlayer insulating layer is provided on the first interlayer insulating layer. The second interlayer insulating layer defines a trench such that at least a portion of an upper surface of the first interlayer insulating layer is exposed. A resistor pattern is provided in the trench such that the at least a portion of the resistor pattern contacts the exposed portion of the first interlayer insulating layer. Related methods are also provided.

Abstract: In a channel region between the source/drain diffusion layers, impurities of the same conductivity type as the well are doped in an area apart from the diffusion regions. By using as a mask the gate formed in advance, tilted ion implantation in opposite directions is performed to form the diffusion layers and heavily impurity doped region of the same conductivity type as the well in a self-alignment manner relative to the gate.

Abstract: A method of fabricating a semiconductor device includes forming a resist pattern so that an opening between select gates of a select gate transistor is formed in a memory cell region, implanting threshold-adjusting ions under the select gate with the resist pattern serving as a mask and removing an oxide film, forming a nitride film and an interlayer insulation film after the resist pattern has been removed, forming a resist pattern used to form a contact hole between the select gates and a contact hole for a transistor to be formed in the peripheral circuit region, the transistor having a higher breakdown voltage than a memory cell transistor and etching the interlayer insulation film, the nitride film and the gate insulation film individually with the resist pattern serving as a mask.

Abstract: A strained channel NMOS and PMOS device pair including fully silicided gate electrodes and method for forming the same, the method including providing a semiconductor substrate including NMOS and PMOS device regions including respective gate structures including polysilicon gate electrodes; forming recessed regions on either side of a channel region including at least one of the NMOS and PMOS device regions; backfilling portions of the recessed regions with a semiconducting silicon alloy to exert a strain on the channel region; forming offset spacers on either side of the gate structures; thinning the polysilicon gate electrodes to a silicidation thickness to allow full metal silicidation through the silicidation thickness; ion implanting the polysilicon gate electrodes to adjust a work function; and, forming a metal silicide through the silicidation thickness to form metal silicide gate electrodes.

Abstract: A metal-insulator-metal (MIM) capacitor is provided. The bottom electrode of the MIM capacitor is electrically connected to a connection node. The connection node may be, for example, a contact formed in an interlayer dielectric, a polysilicon connection node, a doped polysilicon or silicon region, or the like. A contact provides an electrical connection between the connection node and components formed above the connection node. A second contact provides an electrical connection to the top electrode.

Abstract: A decoupling capacitor is provided for a semiconductor device and may include a first low dielectric insulator layer and a low resistance conductor formed into at least two interdigitized patterns on the surface of the first low dielectric insulator in a single interconnect plane. A high dielectric constant material may be provided between the two patterns. A circuit for testing a plurality of these capacitors is also provided which includes a charge monitoring circuit, a coupling circuit and a control circuit.

Abstract: A trench capacitor DRAM cell in an SOI wafer uses the silicon device layer in the array as part of passing wordlines, stripping the silicon device layer in the array outside the wordlines and uses the BOX layer as the array top oxide separating the passing wordlines from the substrate.

Abstract: The present invention provides a method for fabricating a trench capacitor with an insulation collar in a substrate, which is electrically connected to the substrate on one side via a buried contact, in particular for a semiconductor memory cell with a planar selection transistor that is provided in the substrate and connected via the buried contact The invention likewise provides a corresponding trench capacitor.

Abstract: A method of manufacturing a ferroelectric film capacitor includes forming a platinum film used as an electrode material over a whole surface of a silicon substrate, batch-etching the platinum film to form opposite electrodes that serve as a pair of capacitor electrodes, and embedding a ferroelectric film corresponding to a dielectric film of the capacitor into a portion interposed between the pair of opposite electrodes.

Abstract: A method of forming a bit line contact via. The method includes providing a substrate having a transistor with a gate electrode, drain region, and source region, forming a conductive layer overlying the drain region, conformally forming an insulating barrier layer overlying the substrate, blanketly forming a dielectric layer overlying the insulating barrier layer, and forming a via through the dielectric layer and insulating barrier layer, exposing the conductive layer.

Abstract: A semiconductor device, which ensures device reliability especially in fine regions and enables great capacitance and high-speed operations, has memory cells including, in a first region of a main surface of a semiconductor substrate, a gate insulating film, a floating gate electrode, an interlayer insulating film, a control gate electrode, and source and drain regions of the second conduction type arranged in a matrix, with a shallow isolation structure for isolating the memory cells. When using a shallow structure buried with an insulating film for element isolation, the isolation withstand voltage in fine regions can be prevented from lowering and the variation in threshold level of selective transistor can be reduced. When the memory cells in a memory mat are divided by means of selective transistors, the disturb resistance of the memory cells can be improved.

Abstract: A method for fabricating the semiconductor device includes forming linear field oxide regions on a semiconductor substrate; forming gate oxide lines on the semiconductor substrate between the field oxide regions; forming gate lines on the field oxide regions and the gate oxide lines, the gate lines being substantially perpendicular to the field oxide regions; etching the gate oxide lines and the field oxide regions between the gate lines; and forming a self-aligned source (SAS) region by injecting impurity ions into the etched regions, the impurity ion being injected in a direction at a predetermined angle other than 90° relative to the semiconductor substrate.

Abstract: Memory cell having an auxiliary substrate, on which a first gate insulating layer is formed, a floating gate formed on the first gate insulating layer, an electrically insulating layer formed on the floating gate, a memory gate electrode formed on the electrically insulating layer, a substrate fixed to the memory gate electrode, a second gate insulating layer formed on a part of a surface of the auxiliary substrate, which surface is uncovered by partially removing the auxiliary substrate, a read gate electrode formed on the second gate insulating layer, and two source/drain regions located essentially in a surface region of the remaining material of the auxiliary substrate that is free of the second gate insulating layer and the read gate electrode, a channel region located between the two source/drain regions, wherein the channel region at least partly laterally overlaps the floating gate and the read gate electrode.

Abstract: A method of driving a dual-gated MOSFET having a Miller capacitance between the MOSFET gate and drain includes preparing the MOSFET to switch from a blocking mode to a conduction mode by applying to the MOSFET shielding gate a first voltage signal having a first voltage level. The first voltage level is selected to charge the Miller capacitance and thereby reduce switching losses. A second voltage signal is applied to the switching gate to switch the MOSFET from the blocking to the conduction mode. The first voltage signal is then changed to a level selected to reduce the conduction mode drain-to-source resistance and thereby reduce conduction losses. The first voltage signal is returned to the first voltage level to prepare the MOSFET for being switched from the conduction mode to the blocking mode.

Abstract: The invention provides a semiconductor device exhibiting a stable and high breakdown voltage, which is manufactured at a low manufacturing cost. The semiconductor device of the invention includes an n-type silicon substrate; a p-type base region in the surface portion of substrate; an n-type drain region in the surface portion of n-type substrate; a p-type offset region in the surface portion of n-type substrate; an n-type source region in the surface portion of p-type base region; a p-type contact region in the surface portion of p-type base region; a gate electrode above the extended portion of p-type base region extending between n-type source region and n-type substrate (or p-type offset region), with a gate insulation film interposed therebetween; an insulation film on gate electrode and p-type offset region; a source electrode on n-type source region; and a drain electrode on n-type drain region.

Abstract: A method of forming an integrated circuit employable with a power converter. In one embodiment, the method of forming the integrated circuit includes forming a power switch of a power train of the power converter on a semiconductor substrate, and forming a driver switch of a driver configured to provide a drive signal to the power switch and embodied in a transistor. The method of forming the transistor includes forming a gate over the semiconductor substrate, and forming a source/drain by forming a lightly doped region adjacent a channel region recessed into the semiconductor substrate and forming a heavily doped region adjacent the lightly doped region. The method of forming the transistor further includes forming an oppositely doped well within the channel region, and forming a doped region with a doping concentration profile less than the heavily doped region between the heavily doped region and the oppositely doped well.

Abstract: A method for manufacturing an anti-punch through semiconductor device is described. The method is applied to a substrate having a plurality of device isolation structures in parallel arrangements and the upper surface of the device isolation structures is protruded from the surface of the substrate. A plurality of conductive layers in parallel arrangement is formed on the substrate and crosses the device isolation structures. A plurality of trench devices is formed between device isolation structures under the conductive layers. Each trench device includes a first conductive doping region at the bottom of the trench. The method further includes forming spacers on the sidewalls of the device isolation structures and the conductive layers. A dopant implant process is then performed by using the spacers as a mask to form a second conductive doping region between adjacent first conductive doping regions.

Abstract: A non-volatile memory (NVM) has a silicon germanium (SiGe) drain and a silicon carbon (SiC) source. The source being SiC provides for a stress on the channel that improves N channel mobility. The SiC also has a larger bandgap than the substrate, which is silicon. This results in it being more difficult to generate electron/hole pairs by impact ionization. Thus, it can be advantageous to use the SiC region for the drain during a read. The SiGe is used as the drain for programming and erase. The SiGe, having a smaller bandgap than the silicon substrate results in improved programming by generating electron/hole pairs by impact ionization and improved erasing by generating electron hole/pairs by band-to-band tunneling, both at lower voltage levels.

Abstract: An interfacial oxide layer (185) is formed in the emitter regions of the NPN transistor (280, 220) and the PNP transistor (290, 200). Fluorine is selectively introduced into the polysilicon emitter region of the NPN transistor (220) to reduce the 1/f noise in the NPN transistor.

Abstract: This invention adds to the art of replacement source-drain cMOS transistors. Processes may involve etching a recess in the substrate material using one equipment set, then performing deposition in another. Disclosed is a method to perform the etch and subsequent deposition in the same reactor without atmospheric exposure. In-situ etching of the source-drain recess for replacement source-drain applications provides several advantages over state of the art ex-situ etching. Transistor drive current is improved by: (1) Eliminating contamination of the silicon-epilayer interface when the as-etched surface is exposed to atmosphere and (2) Precise control over the shape of the etch recess. Deposition may be done by a variety of techniques including selective and non-selective methods. In the case of blanket deposition, a measure to avoid amorphous deposition in performance critical regions is also presented.

Abstract: A method to achieve controlled conductivity in microfluidic devices, and a device formed thereby. The method comprises forming a microchannel or a well in an insulating material, and ion implanting at least one region of the insulating material at or adjacent the microchannel or well to increase conductivity of the region.

Abstract: CMOS integrated circuit devices include an electrically insulating layer and an unstrained silicon active layer on the electrically insulating layer. An insulated gate electrode is also provided on a surface of the unstrained silicon active layer. A Si1-xGex layer is also disposed between the electrically insulating layer and the unstrained silicon active layer. The Si1-xGex layer forms a first junction with the unstrained silicon active layer and has a graded concentration of Ge therein that decreases monotonically in a first direction extending from a peak level towards the surface of the unstrained silicon active layer. The peak Ge concentration level is greater than x=0.15 and the concentration of Ge in the Si1-xGex layer varies from the peak level to a level less than about x=0.1 at the first junction. The concentration of Ge at the first junction may be abrupt. More preferably, the concentration of Ge in the Si1-xGex layer varies from the peak level where 0.2<x<0.

Abstract: A conveyance system for a semiconductor wafer can be used without any change before and after a support plate is adhered to the wafer. Also, the finish accuracy of the wafer and the positioning accuracy between the wafer and the support plate can be relaxed, thus improving the manufacturing efficiency. The wafer is formed on its peripheral portion with a stepped portion, which is deeper than a finished thickness obtained by partial removal of the rear surface thereof and which can be eliminated by the partial removal of the wafer rear surface. The separation portion has a length which extends radially outward from a flat surface, and which is greater than a total sum of a maximum-minimum difference between the finish allowances of the diameters of the wafer and the support plate, and a maximum value of a positioning error between the wafer and the support plate generated upon adhesion thereof.

Abstract: Three-dimensional structures are electrochemically fabricated by depositing a first material onto previously deposited material through voids in a patterned mask where the patterned mask is at least temporarily adhered to a substrate or previously formed layer of material and is formed and patterned onto the substrate via a transfer tool patterned to enable transfer of a desired pattern of precursor masking material. In some embodiments the precursor material is transformed into masking material after transfer to the substrate while in other embodiments the precursor is transformed during or before transfer. In some embodiments layers are formed one on top of another to build up multi-layer structures. In some embodiments the mask material acts as a build material while in other embodiments the mask material is replaced each layer by a different material which may, for example, be conductive or dielectric.

Abstract: A catalyst element remaining in a first semiconductor film subjected to a first heat treatment (crystallization) is moved and concentrated/collected by subjecting a second semiconductor film which is formed on the first semiconductor film and contains a rare gas element to a second heat treatment. That is, the rare gas element is incorporated into the second semiconductor film to generate a strain field as a gettering site.

Abstract: In a method of fabricating a radiation-emitting semiconductor chip based on AlGaInP, comprising the method steps of preparing a substrate, applying to the substrate a semiconductor layer sequence comprising a photon-emitting active layer, and applying a transparent decoupling layer comprising(Gax(InyAl1?y)1?xP wherein 0.8?x and 0?y?1, it is provided according to the invention that the substrate is made of germanium and that the transparent decoupling layer is applied at low temperature.

Abstract: A method to create a polysilicon layer with large grains and uniform grain density is described. A first amorphous silicon layer is formed. A crystallizing agent is selectively introduced in a substantially symmetric pattern, preferably symmetric in two dimensions, across an area of the first amorphous layer. The crystallizing agent may be, for example, silicon nuclei, germanium, or laser energy. A mask layer is formed on the amorphous silicon layer, and holes etched in the mask layer in a symmetric pattern to expose the amorphous layer to, for example, silicon nuclei or germanium) only in the holes. The mask layer is removed and a second amorphous layer formed on the first. If laser energy is used, no mask layer or second amorphous layer is generally used. The wafer is annealed to form a polysilicon layer with substantially no amorphous silicon remaining between the grains.

Abstract: A gallium nitride layer is laterally grown into a trench in the gallium nitride layer, to thereby form a lateral gallium nitride semiconductor layer. At least one microelectronic device may then be formed in the lateral gallium nitride semiconductor layer. Dislocation defects do not significantly propagate laterally into the lateral gallium nitride semiconductor layer, so that the lateral gallium nitride semiconductor layer is relatively defect free.

Abstract: The invention relates to a method for production of deep p regions in silicon, with the method having the following step: bombardment of an n substrate section, an n epitaxial section or an exposed weakly doped n region of a semiconductor component that is to be produced with high-energy particles, whose energy is chosen such that the previous n region is redoped to form a p region to the desired depth after a specific healing time at a specific healing temperature after the bombardment, and to its use for the production of semiconductor components, for example in order to carry out isolating diffusion.

Abstract: A method of manufacturing a memory device addressing reliability and refresh characteristics through the use of a multilayered doped conductor, and a method making is described. The multilayered doped conductor creates a high dopant concentration in the active area close to the channel region. The rich dopant layer created by the multilayered doped conductor is less susceptible to depletion from trapped charges in the oxide. This improves device reliability at burn-in and lowers junction leakage, thereby providing a longer period between refresh cycles.

Abstract: A manufacturing method for forming a region into which impurity ions are implanted, and an electrode is coupled to the region, in a self-aligned manner. An oxide film is formed on an n-type semiconductor layer composed of a silicon carbide semiconductor, and then the oxide film on regions in which source and drain regions are to be formed is removed by etching. Impurity ions are implanted into an exposed semiconductor layer and heat treatment is performed for activating the implanted impurity ions. A metal film to serve as ohmic electrodes is formed on the entire surface, and then the oxide film is removed by etching to thereby form a source electrode and a drain electrode. Leaving a part of the oxide film on regions on which source and drain electrodes are to be formed can prevent the oxide film from being deformed during the heat treatment for activation.

Abstract: A compound semiconductor device including: an isolated mesa section on which an upper surface having two pairs of parallel sides is formed by mesa etching a compound semiconductor wafer, wherein the mesa section is formed from at least a forward mesa surface which is a mesa section side surface having an obtuse angle against a wafer surface and a backward mesa surface which is a mesa section side surface having an acute angle against the wafer surface, the two mesa surfaces being recognized when viewed from an X direction parallel to one pair of the two parallel sides of the upper surface of the mesa section.