Abstract: A low k dielectric stack having an effective dielectric constant k, of about 3.0 or less, in which the mechanical properties of the stack are improved by introducing at least one nanolayer into the dielectric stack. The improvement in mechanical properties is achieved without significantly increasing the dielectric constant of the films within the stack and without the need of subjecting the inventive dielectric stack to any post treatment steps. Specifically, the present invention provides a low k dielectric stack that comprises at least one low k dielectric material and at least one nanolayer present within the at least one low k dielectric material.

Abstract: A method for fabricating a 3-D monolithic memory device. Silicon-oxynitride (SixOyNz) on amorphous carbon is used an effective, easily removable hard mask with high selectivity to silicon, oxide, and tungsten. A silicon-oxynitride layer is etched using a photoresist layer, and the resulting etched SixOyNz layer is used to etch an amorphous carbon layer. Silicon, oxide, and/or tungsten layers are etched using the amorphous carbon layer. In one implementation, conductive rails of the 3-D monolithic memory device are formed by etching an oxide layer such as silicon dioxide (SiO2) using the patterned amorphous carbon layer as a hard mask. Memory cell diodes are formed as pillars in polysilicon between the conductive rails by etching a polysilicon layer using another patterned amorphous carbon layer as a hard mask. Additional levels of conductive rails and memory cell diodes are formed similarly to build the 3-D monolithic memory device.

Abstract: A semiconductor structure and method of fabricating the structure. The method includes removing the backside silicon from two silicon-on-insulator wafers having devices fabricated therein and bonding them back to back utilizing the buried oxide layers. Contacts are then formed in the upper wafer to devices in the lower wafer and wiring levels are formed on the upper wafer. The lower wafer may include wiring levels. The lower wafer may include landing pads for the contacts. Contacts to the silicon layer of the lower wafer may be silicided.

Abstract: By forming a conductive material within an etch mask for an anisotropic etch process for patterning openings, such as vias, in a dielectric layer of a metallization structure, the probability for arcing events may be reduced, since excess charge may be laterally distributed. For example, an additional sacrificial conductive layer may be formed or an anti-reflecting coating (ARC) may be provided in the form of a conductive material in order to obtain the lateral charge distribution.

Abstract: In a method of manufacturing a semiconductor device which method is made up of a process of forming a wiring groove using a hard mask, a metal hard mask 107 is used to form a wiring groove 111, allowing the shape of the wiring groove 111 to be stabilized. Furthermore, a part or all of the metal hard mask 107 is removed before the formation of TaN and Cu layers in the wiring groove 111. This enables a reduction in possible damage, which may increase the dielectric constant of the surface of low-dielectric-constant film, and thus in possible inter-wire leakage current. As a result, a reliable semiconductor device can be provided.

Abstract: One of methods of manufacturing a semiconductor device of the present invention is as follows: a first conductive layer is formed, a first insulating layer is formed over the first conductive layer, and a second insulating layer is formed over the first insulating layer; then, a first opening portion is formed in the first insulating layer and the second insulating layer to reach the first conductive layer; a mask layer having low wettability to a composition containing a conductive material is formed over the second insulating layer, and a second opening portion larger than the first opening portion is formed in the second insulating layer; subsequently, the first and second opening portions are filled with the composition containing a conductive material to form a second conductive layer.

Abstract: A method for manufacturing a semiconductor device, in which a substrate is disposed in a chamber and a fluorine-containing silicon oxide film is formed on the substrate using a plasma CVD process. The fluorine-containing silicon oxide film is formed such that the release of fluorine from this silicon oxide layer is suppressed. According to this semiconductor device manufacturing method, a stable semiconductor device can be provided such that the device includes a fluorine-containing silicon oxide film (FSG film) at which the release of fluorine is suppressed, and thus peeling does not occur.

Abstract: A semiconductor device includes a plurality of first group wiring layers laminated on a substrate, and each of the first group wiring layers having a wire formed with a first minimum wire width and a main dielectric film portion; and a plurality of second group wiring layers laminated on a top layer of the plurality of first group wiring layers and each of the second group wiring layers having a wire formed with a second minimum wire width greater than the first minimum wire width and a main dielectric film portion, wherein a main dielectric film portion in a bottom layer of the plurality of second group wiring layers has a relative dielectric constant which is substantially identical to a relative dielectric constant of main dielectric film portions of the other second group wiring layers, and Young's modulus of the main dielectric film portion in the bottom layer of the plurality of second group wiring layers is smaller than those of the main dielectric film portions of the other second group wiring layers

Abstract: There is provided a semiconductor device and method of fabricating the same that employs an insulation film of a borazine-based compound to provided enhanced contact between a material for insulation and that for interconnection, increased mechanical strength, and other improved characteristics. The semiconductor device includes a first insulation layer having a recess with a first conductor layer buried therein, an etching stopper layer formed on the first insulation layer, a second insulation layer formed on the etching stopper layer, a third insulation layer formed on the second insulation layer, and a second conductor layer buried in a recess of the second and third insulation layers. The second and third insulation layers are grown by chemical vapor deposition with a carbon-containing borazine compound used as a source material and the third insulation layer is smaller in carbon content than the second insulation layer.

Abstract: In a method for fabricating a semiconductor device, first, a first metal interconnect is formed in an interconnect formation region, and a second metal interconnect is formed in a seal ring region. Subsequently, by chemical mechanical polishing or etching, the upper portions of the first metal interconnect and the second metal interconnect are recessed to form recesses. A second insulating film filling the recesses is then formed above a substrate, and the upper portion of the second insulating film is planarized. Next, a hole and a trench are formed to extend halfway through the second insulating film, and ashing and polymer removal are performed. Subsequently to this, the hole and the trench are allowed to reach the first metal interconnect and the second metal interconnect.

Abstract: A semiconductor device has first wiring layers 30 and a plurality of dummy wiring layers 32 that are provided on the same level as the first wiring layers 30. The semiconductor device defines a row direction, and first virtual linear lines L1 extending in a direction traversing the row direction. The row direction and the first virtual linear lines L1 define an angle of 2-40 degrees, and the dummy wiring layers 32 are disposed in a manner to be located on the first virtual linear lines L1. The semiconductor device also defines a column direction perpendicular to the row direction, and second virtual linear lines L2 extending in a direction traversing the column direction. The column direction and the second virtual linear lines L2 define an angle of 2-40 degrees, and the dummy wiring layers 32 are disposed in a manner to be located on the second virtual linear lines L2.

Abstract: A plurality of gate lines are formed on a substrate. After depositing a gate insulating layer, a semiconductor layer and a doped amorphous silicon layer are sequentially formed thereon. A lower insulating layer made of silicon nitride and an upper insulating layer made of a photosensitive organic material are deposited thereon after forming data lines and drain electrodes. The upper insulating layer is patterned to form an unevenness pattern on its surface and contact holes on the drain electrodes. The lower insulating layer is patterned together with the gate insulating layer using a photoresist pattern having apertures located in the contact holes to form other contact holes respectively exposing the drain electrodes, portions of the gate lines, and portions of the data lines.

Abstract: Since a power source voltage is generated from a communication signal in a wireless chip, there is a risk that a large amount of voltage be generated in the wireless chip to electrically destroy a circuit in the case of supplying a strong communication signal. Therefore, the present invention is made with an aim to provide a wireless chip having resistance to a strong communication signal. A wireless chip of the present invention has an element in which a power source wire and a grounding wire are electrically short-circuited if a power source voltage exceeds a voltage at which an electric circuit is destroyed, i.e., exceeds the specified voltage range. Accordingly, a wireless chip of the present invention has resistance to a strong communication signal.

Abstract: Methods for fabricating a hybrid interconnect structure that possesses a higher interconnect capacitance in one set of regions than in other regions on the same microelectronic chip. Several methods to fabricate such a structure are provided. Circuit implementations of such hybrid interconnect structures are described that enable increased static noise margin and reduce the leakage in SRAM cells and common power supply voltages for SRAM and logic in such a chip. Methods that enable combining these circuit benefits with higher interconnect performance speed and superior mechanical robustness in such chips are also taught.

Abstract: A method for manufacturing a printed wiring board having one or more layers of a conductive pattern and an insulating pattern, including forming an insulating pattern on an insulating substrate; semi-hardening at least one of the insulating substrate and the insulating pattern; forming a conductive pattern on the insulating substrate and/or the insulating pattern, thereby providing a stack structure; performing a thermal treatment on the stack structure to fully harden the semi-hardened insulating substrate and/or insulating pattern; and firing the conductive pattern. In the method, the conductive pattern and the insulating pattern are simultaneously formed on the same layer using an inkjet process.

Abstract: A method of manufacturing a CMOS image sensor manufacturing includes forming a plurality of metal pads over a semiconductor substrate; electrically connecting the metal pads to lower conductive film patterns of multi-layer metal wires using metal contacts; depositing an insulation film over the metal pads; patterning the insulation film to expose at least a portion of the upper surface of the metal pads; and removing impurities from an uppermost surface of the metal pads.

Abstract: A method and apparatus are described for fabricating an ultra low-k interconnect structure by depositing and curing a first via layer (43) of ultra low dielectric constant (ULK) material, depositing a second uncured trench layer (51) of the same ULK material, selectively etching a via opening (62) and trench opening (72) with a dual damascene etch process which uses a trench etch end point signal from the chemical differences between uncured trench layer (51) and the underlying cured via layer (43), and then curing the second trench layer (83) before forming an interconnect structure (91) by filling the trench opening (72) and via opening (62) with an interconnection material so that there is no additional interface or higher dielectric constant material left behind.

Abstract: A power semiconductor device and a method for its production. The power semiconductor device has at least one power semiconductor chip, which has on its top side and on its back side large-area electrodes. The electrodes are electrically in connection with external contacts by means of connecting elements, the power semiconductor chip and the connecting elements being embedded in a plastic package. This plastic package has a number of layers of plastic, which are pressed one on top of the other and have plane-parallel upper sides. The connecting elements are arranged on at least one of the plane-parallel upper sides, between the layers of plastic pressed one on top of the other, as a patterned metal layer and are electrically in connection with the external contacts by means of contact vias through at least one of the layers of plastic.

Abstract: A chemical-mechanical polishing process for forming a conductive interconnect includes the steps of providing a semiconductor substrate having a first conductive line thereon, and then forming at least one dielectric layer over the substrate and the first conductive line. Next, a chemical-mechanical polishing method is used to polish the surface of the dielectric layer. Thereafter, a cap layer is formed over the polished dielectric layer. The method of forming the cap layer includes depositing silicon oxide using a chemical vapor deposition method with silicane (SiH.sub.4) or tetra-ethyl-ortho-silicate (TEOS) as the main reactive agent. Alternatively, the cap layer can be formed by depositing silicon nitride using a chemical vapor deposition method with silicane or silicon dichlorohydride (SiH.sub.2Cl.sub.2) as the main reactive agent.

Abstract: An electropolishing process for high resolution patterning of noble metals, such as platinum, for forming various semiconductor devices, such as capacitors or wiring patterns is disclosed.

Abstract: A process of an embedded circuit structure is provided. A complex metal layer, a prepreg, a supporting board, another prepreg and another complex metal layer are laminated together, wherein each of the complex metal layers has an inner metal layer and an outer metal layer stacked on the inner metal layer, the roughness of the outer surfaces of the inner metal layers is less than the roughness of the second outer surfaces of the outer metal layers, and the outer surfaces of the outer metal layers after laminating are exposed outwards. Each of two patterned photoresist layers is respectively formed on the outer surfaces of the outer metal layers. A metal material is created on portions of the outer surfaces of the outer metal layers not covered by the patterned photoresist layers to form two patterned circuit layers. The patterned photoresist layers are then removed to form a laminating structure.

Abstract: A method of forming an interconnect structure comprising: forming a sacrificial inter-metal dielectric (IMD) layer over a substrate, wherein the sacrificial IMD layer comprising a carbon-based film, such as amorphous carbon, advanced patterning films, porous carbon, or any combination thereof; forming a plurality of metal interconnect lines within the sacrificial IMD layer; removing the sacrificial IMD layer, with an oxygen based reactive process; and depositing a non-conformal dielectric layer to form air gaps between the plurality of metal interconnect lines. The metal interconnect lines may comprise copper, aluminum, tantalum, tungsten, titanium, tantalum nitride, titanium nitride, tungsten nitride, or any combination thereof. Carbon-based films and patterned photoresist layers may be simultaneously removed with the same reactive process.

Abstract: Methods are provided for forming contacts for a semiconductor device. The methods may include depositing various materials, such as polysilicon, nitride, oxide, and/or carbon materials, over the semiconductor device. The methods may also include forming a contact hole and filling the contact hole to form the contact for the semiconductor device.

Abstract: A novel method for enhancing interface adhesion between adjacent dielectric layers, particularly between an etch stop layer and an overlying dielectric layer having a low dielectric constant (k) in the formation of metal interconnects during the fabrication of integrated circuits on semiconductor wafer substrates. The method may include providing a substrate, providing an etch stop layer on the substrate, providing an oxygen-rich dielectric pre-layer on the etch stop layer and providing a major dielectric layer on the oxygen-rich dielectric pre-layer. Metal interconnects are then formed in the dielectric layers. The oxygen-rich dielectric pre-layer between the etch stop layer and the upper dielectric layer prevents or minimizes peeling and cracking of the layers induced by stresses that are caused by chemical mechanical planarization of metal layers and/or chip packaging.

Abstract: The present invention discloses a MEMS device with particles blocking function, and a method for making the MEMS device. The MEMS device comprises: a substrate on which is formed a MEMS device region; and a particles blocking layer deposited on the substrate.

Abstract: A method is provided which includes forming a metal layer and converting at least a portion of the metal layer to a hydrated metal oxide layer. Another method is provided which includes selectively depositing a dielectric layer upon another dielectric layer and selectively depositing a metal layer adjacent to the dielectric layer. Consequently, a microelectronic topography is formed which includes a metal feature and an adjacent dielectric portion comprising lower and upper layers of hydrophilic and hydrophobic material, respectively. A topography including a metal feature having a single layer with at least four elements lining a lower surface and sidewalls of the metal feature is also provided herein. The fluid/s used to form such a single layer may be analyzed by test equipment configured to measure the concentration of all four elements. In some cases, the composition of the fluid/s may be adjusted based upon the analysis.

Abstract: Methods for substrate processing are described. The methods include forming a material layer on a substrate. The methods include selecting constituents of a molecular masking layer (MML) to remove an effect of variations in the material layer as a result of substrate processing. The methods include normalizing the surface characteristics of the material layer by selectively depositing the MML on the material layer.

Abstract: In order to block hydrogen ions produced when forming an interlayer insulating film by HDP-CVD or the like to thereby suppress an adverse effect of the hydrogen ions on a device, in a semiconductor device including a contact layer, a metal interconnection and an interlayer insulating film on a semiconductor substrate having a gate electrode formed thereon, the interlayer insulating film is formed on the metal interconnection by bias-applied plasma CVD using source gas containing hydrogen atoms, and a silicon oxynitride film is provided in the underlayer of the metal interconnection and the interlayer insulating film.

Abstract: An integrated circuit structure comprising an air gap and methods for forming the same are provided. The integrated circuit structure includes a conductive line; a self-aligned dielectric layer on a sidewall of the conductive line; an air-gap horizontally adjoining the self-aligned dielectric layer; a low-k dielectric layer horizontally adjoining the air-gap; and a dielectric layer on the air-gap and the low-k dielectric layer.

Abstract: An interconnection structure for a semiconductor device includes an inter-level insulation layer disposed on a semiconductor substrate. First contact constructions penetrate the inter-level insulation layer. Second contact constructions penetrate the inter-level insulation layer. Metal interconnections connect the first contact constructions to the second contact constructions on the inter-level insulation layer. The first contact constructions include first and second plugs stacked in sequence and the second contact constructions include the second plug.

Abstract: A method for forming a semiconductor structure includes forming a sacrificial layer over a substrate. A first dielectric layer is formed over the sacrificial layer. A plurality of conductive structures are formed within the sacrificial layer and the first dielectric layer. The sacrificial layer is treated through the first dielectric layer, at least partially removing the sacrificial layer and forming at least one air gap between two of the conductive structures. A surface of the first dielectric layer is treated, forming a second dielectric layer over the first dielectric layer, after the formation of the air gap. A third dielectric layer is formed over the second dielectric layer. At least one opening is formed within the third dielectric layer such that the second dielectric layer substantially protects the first dielectric layer from damage by the step of forming the opening.

Abstract: A method for forming a structure includes forming at least one feature across a surface of a substrate. A nitrogen-containing dielectric layer is formed over the at least one feature. A first portion of the nitrogen-containing layer on at least one sidewall of the at least one feature is removed at a first rate and a second portion of the nitrogen-containing layer over the substrate adjacent to a bottom region of the at least one feature is removed at a second rate. The first rate is greater than the second rate. A dielectric layer is formed over the nitrogen-containing dielectric layer.

Abstract: A metal interconnection method of a semiconductor device includes forming a copper layer on a semiconductor substrate and planarizing the copper layer. Two thermal treatments are performed at different temperatures between formation of the copper layer and planarization of the copper layer.

Abstract: The present invention provides a method of manufacturing a semiconductor device, which comprises steps of forming a plurality of wirings on a first insulating film formed on a semiconductor substrate so as to adjoin one another, forming a second insulating film on the first insulating film by a plasma CVD method and covering the wirings with the second insulating film in such a manner that air gaps are formed between the respective adjacent wirings, forming a third insulating film on the second insulating film by a high density plasma CVD method, and forming a fourth insulating film high in moisture resistance on the third insulating film.

Abstract: A low-cost and efficient process produces self-aligned vias in dielectric polymer films that provides electrical connection between a top conductor and a bottom conductor. The process is achieved by printing conductive posts on the first patterned conductive layer, followed by the deposition of an unpatterned layer dielectric, followed by the deposition of a second patterned conductive layer. The vias are formed during the flash annealing of the post after the dielectric is deposited, but before the second conductive layer is deposited. In this process, the post material is annealed with a flash of light, resulting in a release of energy which removes the dielectric on the top of the post.

Abstract: An MRAM device includes an array of magnetic memory cells having an upper conductive layer and a lower conductive layer separated by a barrier layer. To reduce the likelihood of electrical shorting across the barrier layers of the memory cells, spacers can be formed around the upper conductive layer and, after the layers of the magnetic memory cells have been etched, the memory cells can be oxidized to transform any conductive particles that are deposited along the sidewalls of the memory cells as byproducts of the etching process into nonconductive particles. Alternatively, the lower conductive layer can be repeatedly subjected to partial oxidation and partial etching steps such that only nonconductive particles can be thrown up along the sidewalls of the memory cells as byproducts of the etching process.

Abstract: A method of producing a semiconductor device having a plurality of wiring layers forms a first interlayer-insulating film, forms a plurality of grooves for wiring in the first interlayer-insulating film, fills metallic films in the grooves to form wirings, etches the first interlayer-insulating film with the wirings as a mask and removes the interlayer-insulating film between the wirings to provide grooves to be filled, and fills a second interlayer-insulating film made of a material of low dielectric constant in the grooves to be filled.

Abstract: Methods of forming metal silicide layers. The methods include: forming a silicon-rich layer between dielectric layers; contacting the silicon-rich layer with a metal layer and heating the silicon rich-layer and the metal layer to diffuse metal atoms from the metal layer into the silicon layer to form a metal silicide layer.

Abstract: Methods of forming an interlayer dielectric having an air gap are provided including forming a first insulating layer on a semiconductor substrate. The first insulating layer defines a trench. A metal wire is formed in the trench such that the metal wire is recessed beneath an upper surface of the first insulating layer. A metal layer is formed on the metal wire, wherein the metal layer includes a capping layer portion filling the recess, a upper portion formed on the capping layer portion, and an overhang portion formed on the portion of the first insulating layer adjacent to the trench protruding sideward from the upper portion. The first insulating layer is removed and a second insulating layer is formed on the semiconductor substrate to cover the metal layer, whereby an air gap is formed below the overhang portion of the metal layer. A portion of the second insulating layer is removed to expose the upper portion of the metal layer. The upper portion and the overhang portion of the metal layer are removed.

Abstract: A method of forming a small pitch pattern using double spacers is provided. A material layer and first hard masks are used and characterized by a line pattern having a smaller line width than a separation distance between adjacent mask elements. A first spacer layer covering sidewall portions of the first hard mask and a second spacer layer are formed, and spacer-etched, thereby forming a spacer pattern-shaped second hard mask on sidewall portions of the first hard mask. A portion of the first spacer layer between the first hard mask and the second hard mask is selectively removed. The material layer is selectively etched using the first and second hard masks as etch masks, thereby forming the small pitch pattern.

Abstract: In a semiconductor device, an insulating interlayer having a groove is formed on an insulating underlayer. A silicon-diffused metal layer including no metal silicide is buried in the groove. A metal diffusion barrier layer is formed on the silicon-diffused metal layer and the insulating interlayer.

Abstract: The present invention related to a method for manufacturing a semiconductor device. More particularly, this method describes how to manufacture a semiconductor device having a porous, low dielectric constant layer formed between metal lines, comprising an insulation layer enveloping fillers.

Abstract: This invention relates to a process for manufacturing interconnection structures, including: a) the formation on a substrate of a first layer comprising one or several conducting zones (24) and one or several insulating zones made of an organic material (26), b) coverage of this first layer by a porous layer (28), c) consumption and elimination of at least part of the organic material through the porous layer, using enzymes and/or proteins.

Abstract: A method and structure are provided for implementing vertical airgap structures between chip metal layers. A first metal layer is formed. A first layer of silicon dioxide dielectric is deposited onto the first metal layer. A vertical air gap is etched from the first layer of silicon dioxide dielectric above the first metal layer. A second layer of silicon dioxide dielectric is deposited and the vertical air gap is sealed. A next trace layer is etched from the second layer of silicon dioxide dielectric and a via opening is etched from the second and first layers of silicon dioxide dielectric. Then metal is deposited into the next trace layer and metal is deposited into the via opening.

Abstract: Interconnect structures possessing an organosilicate glass based material for 90 nm and beyond BEOL technologies in which a multilayer hardmask using a line-first approach are described. The interconnect structure of the invention achieves respective improved device/interconnect performance and affords a substantial dual damascene process window owing to the non-exposure of the OSG material to resist removal plasmas and because of the alternating inorganic/organic multilayer hardmask stack. The latter feature implies that for every inorganic layer that is being etched during a specific etch step, the corresponding pattern transfer layer in the field is organic and vice-versa.

Abstract: A manufacturing method of a dual damascene structure is provided. First, a first dielectric layer, a second dielectric layer, and a mask layer are formed. A first trench structure is formed in the mask layer. A via structure is formed in the mask layer, the second dielectric layer, and the first dielectric layer. A portion of the second dielectric layer is then removed, so as to transform the first trench structure into a second trench structure. Here, a bottom of the second trench structure exposes the first dielectric layer.

Abstract: An integrated circuit interconnect structure. The structure includes a substrate and a layer of transistor elements overlying the substrate. A first interlayer dielectric layer is formed overlying the layer of transistor elements. An etch stop layer is formed overlying the first interlayer dielectric layer. A contact structure including metallization is within the first interlayer dielectric layer and a metal layer is coupled to the contact structure. A passivation layer is formed overlying the metal layer. Preferably, an air gap layer is coupled between the passivation layer and the metal layer, the air gap layer allowing a portion of the metal layer to be free standing. Depending upon the embodiment, a portion of the air gap layer may be filled with silicon bearing nanoparticles, which may be oxidized at low temperatures. This oxidized layer provides mechanical support and low k dielectric characteristics. Preferably, a portion of the air gap layer is filled with a low k dielectric material as well.

Abstract: A method for determining conditions for forming a dielectric SiOCH film, includes: (i) forming a dielectric SiOCH film on a substrate under conditions; (ii) evaluating the conditions using a ratio of Si—CH3 bonding strength to Si—O bonding strength of the film as formed in step (i); (iii) if the ratio is 2.50 % or higher, confirming the conditions, and if the ratio is less than 2.50 %, changing the conditions by changing at least one of the susceptor temperature, the distance between upper and lower electrodes, the RF power, and the curing time; and (iv) repeating steps (i) to (iii) until the ratio is 2.50 % or higher.

Abstract: A metal wiring of a semiconductor device and a forming method thereof are provided. A dielectric layer is formed on a semiconductor substrate including a lower metal wiring. A SOG (spin on glass) coating layer is formed on the dielectric layer to inhibit material from another layer from infiltrating into the dielectric layer.

Abstract: MEMS devices (such as interferometric modulators) may be fabricated using a sacrificial layer that contains a heat vaporizable polymer to form a gap between a moveable layer and a substrate. One embodiment provides a method of making a MEMS device that includes depositing a polymer layer over a substrate, forming an electrically conductive layer over the polymer layer, and vaporizing at least a portion of the polymer layer to form a cavity between the substrate and the electrically conductive layer.