Abstract: A semiconductor device may include a multi-layered source layer, conductive patterns, interlayer insulating layers, and a channel pillar. The multi-layered source layer may include a lower source layer, an interlayer source layer, and an upper source layer. The conductive patterns and interlayer insulating layers may be alternately disposed on the multi-layered source layer. The channel pillar may penetrate the conductive patterns. The interlayer insulating layers, the upper source layer, and the interlayer source layer, the channel pillar may extend into the lower source layer. The channel pillar may be in contact with the interlayer source layer. Doped regions having various structures can be formed at a lower portion of the channel pillar, thereby improving the operational reliability of the semiconductor device.

Abstract: A memory device has first and second memory cells in and over a substrate. A first doped region is in a first active region. A top surface of the first active region is substantially coplanar with a top surface of the first doped region. A control gate is over the first doped region and extends over a first side of the first doped region and over a second side of the first doped region. A charge storage layer is between the first control gate and the first active region including between the first select gate and the first doped region. A first select gate is over the first active region on the first side of the first doped region and adjacent to the control gate. A second select gate is over the first active region on the second side of the first doped region and adjacent to the control gate.

Abstract: An array structure of a single-poly nonvolatile memory includes a first MTP section, a first OTP section and a ROM section. The first MTP section includes a plurality of MTP cells, the first OTP section includes a plurality of OTP cells and the first ROM section includes a plurality of ROM cells. The first MTP is connected to a first word line, a first source line, a first erase line and a plurality of bit lines. The first OTP section is connected to a second word line, a second source line and the plurality of bit lines shared with the first MTP section. The first ROM section is connected to a third word line, a third source line and the plurality of bit lines shared with the first MTP section.

Abstract: The present invention relates generally to integrated circuits and more particularly, to a structure and method of forming a hybrid circuit including a tunnel field-effect transistor (TFET) and a conventional field effect transistor (FET). Embodiments of the present invention include a hybrid amplifier which features a TFET common-source feeding a common-gate conventional FET (e.g. a MOSFET). A TFET gate may be electrically isolated from an output from a conventional FET. Thus, a high impedance input may be received by a TFET with a high-isolation output (i.e. low capacitance) at a conventional FET. A hybrid circuit amplifier including a TFET and a conventional FET may have a very high input impedance and a low miller capacitance.

Abstract: Provided is a semiconductor device and a method of fabricating the same. The method may include forming trenches in a substrate and lower gate patterns on the substrate between the trenches, forming sacrificial patterns filling the trenches, forming a porous insulating layer on the lower gate patterns to cover top surfaces of the sacrificial patterns, removing the sacrificial patterns through pores of the porous insulating layer to form air gaps surrounded by the trenches and the porous insulating layer, and forming a liner insulating layer on inner surfaces of the trenches through the pores of the porous insulating layer.

Abstract: A method of forming a semiconductor memory storage device that includes forming first and second doped regions of a first type in a semiconductor substrate and laterally spaced from one another, forming a gate dielectric extends over the semiconductor substrate between the first and second doped regions, forming a floating gate on the gate dielectric, and forming an ultraviolet (UV) light blocking material vertically disposed above the floating gate such that the floating gate remains electrically charged after the semiconductor memory storage device is exposed to UV light.

Abstract: A nonvolatile memory device may include a plurality of memory blocks each including a drain select line, word lines and a source select line, and a pass transistor stage including a plurality of pass transistors formed in series in an active region and suitable for transferring word line voltages to a memory block selected among the memory blocks, in response to a block select signal, wherein the pass transistors each share a drain with a first adjacent pass transistor at one side while sharing a source with a second adjacent pass transistor at the other, and wherein a pair of pass transistors which share the source transfer word line driving signal form drains thereof to a pair of word lines which are included in different memory blocks among the memory blocks, through the source.

Abstract: The present disclosure relates to an integrated circuit (IC), including, a flash memory device region, including a pair of split-gate flash memory cells arranged over a semiconductor substrate. The pair of split gate flash memory cells respectively have a control gate (CG) including a polysilicon gate and an overlying silicide layer. A periphery circuit including, one or more high-k metal gate (HKMG) transistors are arranged over the semiconductor substrate at a position laterally offset from the flash memory device region. The one or more HKMG transistors have a metal gate electrode with an upper surface that is lower than an upper surface of the silicide layer. A method of manufacturing the IC is also provided.

Abstract: A method of designing a charge trapping memory array includes designing a memory array layout. The memory array layout includes a first type of transistors; electrical connections between memory cells of the memory array layout; a first input/output (I/O) interface; and a charge pump. The method further includes modifying the memory array layout, using a processor, to replace the first type of transistors with a second type of transistors different than the first type of transistors. The method further includes modifying the memory array layout, using the processor, to modify the charge pump based on an operating voltage of the second type of transistors.

Abstract: A semiconductor device and method of making such device is presented herein. The method includes disposing a gate layer over a dielectric layer on a substrate and further disposing a cap layer over the gate layer. A first transistor gate is defined having an initial thickness substantially equal to a combined thickness of the cap layer and the gate layer. A first doped region is formed in the substrate adjacent to the first transistor gate. The cap layer is subsequently removed and a second transistor gate is defined having a thickness substantially equal to the thickness of the gate layer. Afterwards, a second doped region is formed in the substrate adjacent to the second transistor gate. The first doped region extends deeper in the substrate than the second doped region, and a final thickness of the first transistor gate is substantially equal to the thickness of the second transistor gate.

Abstract: Memory cells and methods for programming and erasing a memory cell by utilizing a buried select line are described. A voltage potential may be generated between a source-drain region and the buried select line region of the memory cell to store charge in a storage region between the source-drain and buried select line regions. The generated voltage potential causes electrons to either tunnel towards the buried storage region to store electrical charge or away from the buried storage region to discharge electrical charge.

Abstract: An alternating stack of insulating layers and sacrificial material layers can be formed over a substrate. Memory stack structures and a backside trench are formed through the alternating stack. Backside recesses are formed by removing the sacrificial material layers from the backside trench selective to the insulating layers. A cobalt-containing material is deposited such that the cobalt-containing material continuously extends at least between a neighboring pair of cobalt-containing material portions in respective backside recesses. An anneal is performed at an elevated temperature to migrate vertically-extending portions of the cobalt-containing material into the backside recesses, thereby forming vertically separated cobalt-containing material portions confined within the backside recesses. Sidewalls of the insulating layers may be rounded or tapered to facilitate migration of the cobalt-containing material.

Abstract: Various embodiments address various difficulties with source side sensing difficulties in various memory architectures, such as 3D vertical gate flash and multilevel cell memory. One such difficulty is that with source side sensing, the signal amplitude is significantly smaller than drain side sensing. Another such difficulty is the noise and reduced sensing margins associated with multilevel cell memory. In some embodiments the bit line is selectively discharged prior to applying the read bias arrangement.

Abstract: A technique for erasing a ferroelectric field effect transistor (FeFET) memory circuit comprising a plurality memory cells comprising FeFETs is described. Each FeFET comprises a gate stack, a source, a drain, a channel and a bulk substrate region, where the gate stack comprises a gate and a ferroelectric layer disposed between the gate and the channel. A positive or a negative voltage is applied to the source and drain regions of at least one FeFET memory cell depending on the channel type. The gate and bulk substrate regions are held at a ground state during said applying of the positive voltage to the source and drain regions of the FeFET memory cell to cause erasure of the at least one FeFET memory cell. In addition, a FeFET is described with a charge storage layer disposed adjacently to the ferroelectric layer within the gate stack.

Abstract: A semiconductor device includes a substrate, a first transistor, and a second transistor. The first transistor includes a first source terminal formed of a material and connected to a first source, a first drain terminal formed of the material and connected to a first drain, a first gate overlapping a portion of the substrate that is between the first source and the first drain, and a first dielectric layer between the first gate and the substrate. The second transistor includes a control gate formed of the material and overlapping a part of the substrate that is positioned between a second source and a second drain, a second dielectric layer between the control gate and the substrate, a floating gate extending through the second dielectric layer to contact a doped region in the substrate, and an insulating member positioned between the control gate and the floating gate.

Abstract: Suspended charge storage regions are utilized for non-volatile storage to decrease parasitic interferences and increase charge retention in memory devices. Charge storage regions are suspended from an overlying intermediate dielectric material. The charge storage regions include an upper surface and a lower surface that extend in the row and column directions. The upper surface of the charge storage region is coupled to the overlying intermediate dielectric material. The lower surface faces the substrate surface and is separated from the substrate surface by a void. The charge storage region includes a first vertical sidewall and a second vertical sidewall that extend in the column direction and a third vertical sidewall and fourth vertical sidewall that extend in the row direction. The first, second, third, and fourth vertical sidewall are separated from neighboring features of the non-volatile memory by the void. The void may include a vacuum, air, gas, or a liquid.

Abstract: A vertical channel structure including a substrate, a plurality of stacked structures, a charge storage structure, a channel structure and a dielectric structure is provided. The stacked structures are disposed on the substrate. An opening is located between the stacked structures. The charge storage structure is disposed on a sidewall of the opening. The channel structure is disposed on the charge storage structure and on the substrate at a bottom portion of the opening. The dielectric structure includes first and second dielectric layers. The first dielectric layer is disposed on the channel structure. The second dielectric layer is disposed on the first dielectric layer and seals the opening to form a void in the dielectric structure. A top portion of the second dielectric layer is higher than a top portion of the first dielectric layer. The dielectric structure exposes an upper portion of the channel structure.

Abstract: A semiconductor storage device according to an embodiment of the invention includes a semiconductor substrate and a plurality of memory cells on the semiconductor substrate. A first film is provided above the memory cells to form air gaps above a memory string in which the memory cells are connected in series.

Abstract: A memory stack structure can be formed through a stack of an alternating plurality of first material layers and second material layers and through an overlying temporary material layer having a different composition than the first and second material layers. The memory stack structure can include a memory film and a semiconductor channel layer. The overlying temporary material layer is removed selective to the stack to form a lateral recess. Portions of the memory film are removed around the lateral recess, and dopants are laterally introduced into an upper portion of the semiconductor channel to form a self-aligned drain region.

Abstract: A split gate memory device, a semiconductor device and a manufacturing method thereof are provided. In the split gate memory device, an erasing gate is further disposed, wherein the easing gate and a control gate are respectively disposed on two sides of a floating gate. Thus, an erase operation is implemented by the erasing gate instead of the control gate. Accordingly, electric potential applied to the control gate is reduced. Therefore, hot-electron effect in channel region may be avoided, and performance degradation of the memory caused by the hot-electron effect may be avoided as well. Furthermore, as electric potential applied to the control gate is reduced, a gate oxide layer underneath the control gate may be thinner. Accordingly, manufacturing processes of the control gate and the gate oxide layer and that of the gate and the gate oxide layer of a logic transistor in a periphery circuit may be compatible.

Abstract: A nonvolatile memory device having a plurality of unit cells, each of the plurality of unit cells includes a first transistor suitable for having a fixed threshold voltage, and a second transistor suitable for coupling to the first transistor in parallel and having a variable threshold voltage.

Abstract: Semiconductor memory devices and methods of fabricating the same are provided. A semiconductor memory device includes stack gate structures that are spaced apart from each other in a first direction horizontal to a substrate. Each of the stack gate structures includes insulating layers and gate electrodes alternately and repeatedly stacked on the substrate. Vertical channel structures penetrate the stack gate structures. A source plug line is provided between the stack gate structures. The source plug line is in contact with the substrate and extends in a second direction intersecting the first direction. The substrate being in contact with the source plug line includes a plurality of protruding regions formed along the second direction. Each of the protruding regions has a first width, and the protruding regions are spaced apart from each other by a first distance greater than the first width.

Abstract: A fabrication process is provided for a 3D stacked non-volatile memory device which provides a source contact to a bottom of a memory hole in a stack without exposing a programmable material lining of an interior sidewall of the memory hole and without exposing a channel forming region also lining an interior of the memory hole to an energetic and potentially damaging etch environment. The stack includes alternating control gate layers and dielectric layers on a substrate, and the memory hole is etched through the stack before lining an interior sidewall thereof with the programmable material and then with the channel forming material. The process avoids a need to energetically etch down through the memory hole to open up a source contact hole near the bottom of the channel forming material by instead etching upwardly from beneath the memory hole.

Abstract: This semiconductor device comprises: a gate insulating film provided on a surface of a channel layer; a gate electrode provided on an upper surface of the gate insulating film; and a diffusion layer provided in the channel layer. Furthermore, this semiconductor device comprises: a polycrystalline silicon film provided so as to cover a surface of the gate electrode and the diffusion layer; and an inter-layer insulating film provided so as to cover the gate electrode and the polycrystalline silicon film.

Abstract: A nonvolatile semiconductor memory device includes a semiconductor substrate, a memory element including a first gate electrode having a first thickness disposed on a first insulation film on the semiconductor substrate, and a first peripheral element other than a memory element including a second gate electrode having a second thickness disposed on a second insulation film on the semiconductor substrate. The first gate electrode and second gate electrode comprise a plurality of film layers, and the configuration of the film layers are different as between the first gate electrode of the memory element and the second gate electrode of the peripheral element, and the first thickness is different from the second thickness.

Abstract: A memory cell including a drain, a channel, and a floating gate. The channel surrounds the drain and includes a first rounded closed curve structure around the drain. The floating gate is situated over the channel and includes a second rounded closed curve structure over the channel.

Abstract: A method of controlling a photosensor having adjacent light sensitive pixels in which photocharge is generated in depletion zones of the pixels by light incident on the photosensor, comprising applying voltage to gate electrodes of the photopixels so that the depletion zone of one of the pixels extends into and lies under a portion of the depletion region of the other pixel.

Abstract: A vertical NAND string device includes a semiconductor channel, where at least one end portion of the semiconductor channel extends substantially perpendicular to a major surface of a substrate, at least one semiconductor or electrically conductive landing pad embedded in the semiconductor channel, a tunnel dielectric located adjacent to the semiconductor channel, a charge storage region located adjacent to the tunnel dielectric, a blocking dielectric located adjacent to the charge storage region and a plurality of control gate electrodes extending substantially parallel to the major surface of the substrate.

Abstract: A method for manufacturing a semiconductor storage device includes forming a first insulating film on a semiconductor substrate; forming a first conductive layer; forming a trench in the semiconductor substrate and the first conductive layer by etching; forming a deposition layer by depositing an insulating material in the trench; removing by etching a side portion of the deposition layer to form a side surface that has a flat surface and a curved surface with a lower edge that is in contact with a side surface of the first conductive layer and to form a gap between the curved and the side surfaces; forming a second conductive layer; removing the deposition layer until at least the curved surface of the side surface is exposed to form an embedded insulator in the trench; forming a second insulating film; and forming a control gate on the embedded insulator and the second insulating film.

Abstract: A semiconductor device includes bit lines provided in a semiconductor substrate; an ONO film that is provided along the surface of the semiconductor substrate and is made of a tunnel oxide film, a trap layer, and a top oxide film; and an oxide film that is provided on the surface of the semiconductor substrate in the middle between the bit lines and contacts the side face of the ONO film, in which the film thickness of the oxide film is larger than the sum of the thicknesses of the tunnel oxide film and the top oxide film, and smaller than the thickness of the ONO film.

Abstract: A multi-level device includes at least one device region and at least one contact region. The contact region has a stack of alternating plurality of electrically conductive layers and plurality of electrically insulating layers located over a substrate. The plurality of electrically conductive layers form a stepped pattern in the contact region, where each respective electrically insulating layer includes a sidewall and a respective underlying electrically conductive layer in the stack extends laterally beyond the sidewall. Optionally, a plurality of electrically conductive via connections can be formed, which have top surfaces within a same horizontal plane, have bottom surfaces contacting a respective electrically conductive layer located at different levels, and are isolated from one another by at least one trench isolation structure.

Abstract: A structure includes a three-dimensional semiconductor device including a plurality of unit device structures located over a substrate. Each of the unit device structures includes a semiconductor channel including at least a portion extending vertically along a direction perpendicular to a top surface of the substrate, and a drain region contacting a top end of the semiconductor channel. The structure also includes a combination of a plurality of contact pillars and a contiguous volume that laterally surrounds the plurality of contact pillars. The plurality of contact pillars is in contact with the drain regions, and the contiguous volume has a dielectric constant less than 3.9.

Abstract: In one implementation, a semiconductor package includes a first patterned conductive carrier including partially etched segments. The semiconductor package also includes a control FET having a control drain attached to a first partially etched segment of the first patterned conductive carrier. In addition, the semiconductor package includes a sync FET having a sync source and a sync gate attached to respective second and third partially etched segments of the first patterned conductive carrier. The semiconductor package further includes a second patterned conductive carrier having a switch node segment situated over a control source of the control FET and over a sync drain of the sync FET, as well as an inductor coupled between the switch node segment and an output segment of the second patterned conductive carrier.

Abstract: Socket structures that are configured to use area efficiently, and methods for providing socket regions that use area efficiently, are provided. The staircase type contact area or socket region includes dielectric layers between adjacent planar electrodes that partially cover a portion of a planar electrode that does directly underlie an adjacent planar electrode. The portion of a dielectric layer between adjacent planar electrodes can be sloped, such that it extends from an edge of an overlying planar electrode to a point between the edge of an underlying planar electrode and a point corresponding to an edge of the overlying planar electrode.

Abstract: To provide a semiconductor device having a nonvolatile memory improved in characteristics. In the semiconductor device, a nonvolatile memory has a high-k insulating film (high dielectric constant film) between a control gate electrode portion and a memory gate electrode portion and a transistor of a peripheral circuit region has a high-k/metal configuration. The high-k insulating film arranged between the control gate electrode portion and the memory gate electrode portion relaxes an electric field intensity at the end portion (corner portion) of the memory gate electrode portion on the side of the control gate electrode portion. This results in reduction in uneven distribution of charges in a charge accumulation portion (silicon nitride film) and improvement in erase accuracy.

Abstract: A method for manufacturing a non-volatile memory structure includes providing a substrate having a memory region and a logic region defined thereon, masking the logic region while forming at least a first gate in the memory region, forming an oxide-nitride-oxide (ONO) structure under the first gate, forming an oxide structure covering the ONO structure on the substrate, masking the memory region while forming a second gate in the logic region, and forming a first spacer on sidewalls of the first gate and a second spacer on sidewalls of the second gate simultaneously.

Abstract: A memory device includes a memory cell array including a plurality of NAND strings, wherein each of the NAND strings includes a ground selection transistor connected to a ground selection line, memory cells connected to word lines, and a string selection transistor connected to a string selection line, wherein the ground selection line, the word lines, and the string selection line are vertically stacked on a substrate. A control logic adjusts a ground selection line voltage applied to the ground selection line or a string selection line voltage applied to the string selection line to a negative level in at least a portion of a program section during which a program operation related to a memory cell selected from among the memory cells is performed.

Abstract: The disclosure, belonging to the technological field of semiconductor memory, specifically relates to a semi-floating-gate device which comprises at least a semiconductor substrate, a source region, a drain region, a floating gate, a control gate, a perpendicular channel region and a gated p-n junction diode used to connect the floating gate and the substrate. The semi-floating-gate device disclosed in the disclosure using the floating gate to store information and realizing charging or discharging of the floating gate through a gated p-n junction diode boasts small unit area, high chip density, low operating voltage in data storage and strong ability in data retain.

Abstract: Inventive concepts provide semiconductor memory devices and methods of fabricating the same. A stack structure and vertical channel structures are provided on a substrate. The stack structure includes insulating layers and gate electrodes alternately and repeatedly stacked on the substrate. A first vertical channel pattern is disposed in a lower portion of each vertical channel structure. A gate oxide layer is formed on a sidewall of the first vertical channel pattern. A recess region is formed in the substrate between the vertical channel structures. A buffer oxide layer is formed in the recess region. An oxidation inhibiting layer is provided in the substrate to surround the recess region. The oxidation inhibiting layer is in contact with the buffer oxide layer and inhibits growth of the buffer oxide layer.

Abstract: A method of fabricating a semiconductor device includes forming conductive pillars on a substrate, sequentially forming a sacrificial layer and a molding structure between the conductive pillars, forming a conductive layer on the molding structure, such that the conductive layer is connected to the conductive pillars, removing the sacrificial layer to form an air gap, removing the molding structure to form an expanded air gap, and patterning the conductive layer to open the expanded air gap.

Abstract: A method of manufacturing a three-dimensional semiconductor memory device comprises forming a thin layer structure by alternately stacking first and second material layers on a substrate, forming a penetration dent penetrating the thin layer structure and exposing a top surface of the substrate recessed by the penetration dent, forming a vertical insulation layer penetrating the thin layer structure to cover an inner wall of the penetration dent, forming a semiconductor pattern penetrating the vertical insulation layer at the penetration dent to be inserted into the substrate, and forming an oxide layer between the thin layer structure and the substrate by oxidizing a sidewall of the penetration dent.

Abstract: A semi-floating gate transistor structure includes a substrate, a first N-well region and a second N-well region separated from each other in the substrate, and a gate oxide layer on the substrate. The gate oxide layer includes a separation groove disposed on the first N-well region. The semi-floating gate transistor structure further includes a P-type doped floating gate having a first portion filling the separation groove and a second portion integrally formed on the first portion. The first portion of the P-type doped floating gate and the first N-well region form a pn-junction diode.

Abstract: Single spacer processes for multiplying pitch by a factor greater than two are provided. In one embodiment, n, where n?2, tiers of stacked mandrels are formed over a substrate, each of the n tiers comprising a plurality of mandrels substantially parallel to one another. Mandrels at tier n are over and parallel to mandrels at tier n?1, and the distance between adjoining mandrels at tier n is greater than the distance between adjoining mandrels at tier n?1. Spacers are simultaneously formed on sidewalls of the mandrels. Exposed portions of the mandrels are etched away and a pattern of lines defined by the spacers is transferred to the substrate.

Abstract: Provided is a control apparatus which may apply an electric signal to a specific point or area selected from a plane or may receive the signal from the specific point or area. The control apparatus includes an upper electrode and a lower electrode. When it is intended that an electric field is applied to a point in which the upper electrode and the lower electrode come in contact with each other, an electrical bias is applied to the lower electrode, and the upper electrode is maintained in a non-connected state. When it is intended that the bias is selectively applied, the upper electrode is maintained in a grounded state. Therefore, transferring of the field from the lower electrode to a ground electrode disposed at a bottom is shielded, and thus transferring of the electric signal is also blocked.

Abstract: A process for forming tilted edge wordline implants is disclosed. The process includes forming a first drain implant in a substrate, forming a first tilted implant in a substrate adjacent a first edge wordline to supplement said first drain implant where the first tilted implant is provided at a tilt angle from a first direction and forming a second tilted implant in the substrate adjacent a second edge wordline to supplement another first drain implant where the second tilted implant is provided at a tilt angle from a second direction. A second drain implant is formed in the substrate.

Abstract: A film-forming method includes forming a tungsten film or a tungsten oxide film on an object to be processed, forming a seed layer on the tungsten film or the tungsten oxide film, and forming a silicon oxide film on the seed layer, wherein the seed layer formed on the tungsten film or the tungsten oxide film is formed by heating the object to be processed and supplying an aminosilane-based gas to a surface of the tungsten film or the tungsten oxide film.

Abstract: According to one embodiment, a semiconductor memory device includes a stacked body including a plurality of electrode layers separately stacked each other; a plurality of columnar sections provided in the stacked body and extending in a stacking direction of the stacked body; and a first insulating section separating the stacked body. The respective columnar sections include a semiconductor body extending in the stacking direction; and a charge storage film provided between the semiconductor body and the plurality of electrode layers. The first insulating section includes a first air gap.

Abstract: A nonvolatile memory device and method of manufacturing the same are provided. In the nonvolatile memory device, a blocking insulation layer is provided between a trap insulation layer and a gate electrode. A fixed charge layer spaced apart from the gate electrode is provided in the blocking insulation layer. Accordingly, the reliability of the nonvolatile memory device is improved.

Abstract: A film-forming method includes forming a tungsten film or a tungsten oxide film on an object to be processed, heating the object on which the tungsten film or the tungsten oxide film is formed, forming a seed layer on the tungsten film or the tungsten oxide film by supplying an aminosilane-based gas to a surface of the tungsten film or the tungsten oxide film, and forming a silicon oxide film on the seed layer by simultaneously supplying a silicon material gas including silicon and a gas including an oxidizing agent for oxidizing silicon.

Abstract: The present disclosure relates to a method of forming a semiconductor. The method includes heating a substrate in a reaction chamber, supplying to the reaction chamber a first constituent including a metal borohydride wherein the metal borohydride includes at least one of: an alkaline earth metal, a transition metal, or a combination thereof; supplying to the reaction chamber a main-group hydride constituent; and depositing a metal compound on the substrate, wherein the metal compound comprises a) at least one of an alkaline earth metal a transition metal or a combination thereof, b) boron and c) optionally the main group alloying element.