Abstract: A semiconductor structure includes a substrate including a first region and a second region, a first channel layer disposed in the first region and a second channel layer disposed in the second region, a first dielectric layer disposed on the first channel layer and a second dielectric layer disposed on the second channel layer, and a first gate electrode disposed on the first dielectric layer and a second gate electrode disposed on the second dielectric layer. The first channel layer in the first region includes Ge compound of a first Ge concentration, the second channel layer in the second region includes Ge compound of a second Ge concentration. The first Ge concentration in the first channel layer is greater than the second Ge concentration in the second channel layer.

Abstract: A method includes forming a first gate structure over a substrate, where the first gate structure is surrounded by a first dielectric layer; and forming a mask structure over the first gate structure and over the first dielectric layer, where forming the mask structure includes selectively forming a first capping layer over an upper surface of the first gate structure; and forming a second dielectric layer around the first capping layer. The method further includes forming a patterned dielectric layer over the mask structure, the patterned dielectric layer exposing a portion of the mask structure; removing the exposed portion of the mask structure and a portion of the first dielectric layer underlying the exposed portion of the mask structure, thereby forming a recess exposing a source/drain region adjacent to the first gate structure; and filling the recess with a conductive material.

Abstract: An integrated circuit includes a gate structure in contact with a portion of semiconductor material between a source region and a drain region. The gate structure includes gate dielectric and a gate electrode. The gate dielectric includes at least two hybrid stacks of dielectric material. Each hybrid stack includes a layer of low-? dielectric and a layer of high-? dielectric on the layer of low-? dielectric, where the layer of high-? dielectric has a thickness at least two times the thickness of the layer of low-? dielectric. In some cases, the layer of low-? dielectric has a thickness no greater than 1.5 nm. The layer of high-? dielectric may be a composite layer that includes two or more layers of compositionally-distinct materials. The gate structure can be used with any number of transistor configurations but is particularly useful with respect to group III-V transistors.

Abstract: A method of fabricating a metal gate transistor includes providing a substrate. An interlayer dielectric layer covers the substrate. A dummy gate is embedded in the interlayer dielectric layer. A high-k dielectric layer is disposed between the dummy gate and the substrate. Later, the dummy gate is removed to form a trench, and the high-k dielectric layer is exposed through the trench. After the dummy gate is removed, an ion implantation process is performed to implant fluoride ions into the high-k dielectric layer. Finally, after the ion implantation process, a metal gate is formed to fill in the trench.

Abstract: A vertical field effect transistor structure having at least two vertically oriented fins extending from a substrate. The vertical field effect transistor structure further includes a first source/drain region disposed in the substrate between the two vertically oriented fins and under each of the fins. The outer ends of the first source/drain region are in contact with outer ends of the fins. A portion of the first source/drain region extends beyond the fins.

Abstract: A method includes, through a backside of a substrate, removing a portion of a gate structure to form a trench that isolates the gate structure in two portions. The method further includes depositing a sacrificial material within the trench and conformally along sidewalls of the trench, filling a remainder of the trench with a first dielectric material, partially removing the sacrificial material to leave an opening between the first dielectric material and the gate structure, and filling the opening with a work-function metal.

Abstract: An embodiment includes a method of forming a semiconductor device and the resulting device. The method may include forming a source/drain on an exposed portion of a semiconductor layer of a layered nanosheet. The method may include forming a sacrificial material on the source/drain. The method may include forming a dielectric layer covering the sacrificial material. The method may include replacing the sacrificial material with a contact liner. The semiconductor device may include a first gate nanosheet stack and second gate nanosheet stack. The semiconductor device may include a first source/drain in contact with the first nanosheet stack and a second source/drain in contact with the second nanosheet stack. The semiconductor device may include a source/drain dielectric located between the first source/drain and the second source/drain. The semiconductor device may include a contact liner in contact with the first source/drain, the second source/drain and the source/drain dielectric.

Abstract: A tilted nanowire structure is provided which has an increased gate length as compared with a horizontally oriented semiconductor nanowire at the same pitch. Such a structure avoids complexity required for vertical transistors and can be fabricated on a bulk semiconductor substrate without significantly changing/modifying standard transistor fabrication processing.

Abstract: Embodiments of the disclosure are in the field of advanced integrated circuit structure fabrication and, in particular, integrated circuit structures having germanium-based channels are described. In an example, an integrated circuit structure includes a fin having a lower silicon portion, an intermediate germanium portion on the lower silicon portion, and a silicon germanium portion on the intermediate germanium portion. An isolation structure is along sidewalls of the lower silicon portion of the fin. A gate stack is over a top of and along sidewalls of an upper portion of the fin and on a top surface of the isolation structure. A first source or drain structure is at a first side of the gate stack. A second source or drain structure is at a second side of the gate stack.

Abstract: A method of forming a semiconductor structure includes forming first semiconductor devices over a first substrate, forming a first dielectric material layer over the first semiconductor devices, forming vertical recesses in the first dielectric material layer, such that each of the vertical recesses vertically extends from a topmost surface of the first dielectric material layer toward the first substrate, forming silicon nitride material portions in each of the vertical recesses; and locally irradiating a second subset of the silicon nitride material portions with a laser beam.

Abstract: A method includes forming a dummy gate stack, forming a dielectric layer, with the dummy gate stack located in the dielectric layer, removing the dummy gate stack to form a opening in the dielectric layer, forming a metal layer extending into the opening, and etching back the metal layer. The remaining portions of the metal layer in the opening have edges lower than a top surface of the dielectric layer. A conductive layer is selectively deposited in the opening. The conductive layer is over the metal layer, and the metal layer and the conductive layer in combination form a replacement gate.

Abstract: A method includes depositing an etch stop layer over a first conductive feature, performing a first treatment to amorphize the etch stop layer, depositing a dielectric layer over the etch stop layer, etching the dielectric layer to form an opening, etching-through the etch stop layer to extend the opening into the etch stop layer, and filling the opening with a conductive material to form a second conductive feature.

Abstract: A computer-implemented method for measuring a parameter of a semiconductor. A non-limiting example of the computer-implemented method includes receiving, using a processor, a raw signal from a first tool representing a measured parameter of a semiconductor device. The method also receives, using the processor, data on the measured parameter from a second tool, and calculates, using the processor, the measured parameter based on the data received from the second tool and on a constraint based on the raw signal from the first tool.

Abstract: A method includes forming a first dummy gate and a second dummy gate over a fin that protrudes above a substrate; replacing the first dummy gate and the second dummy gate with a first metal gate and a second metal gate, respectively; forming a dielectric cut pattern between the first and the second metal gates, the dielectric cut pattern extending further from the substrate than the first and the second metal gates; forming a patterned mask layer over the first metal gate, the second metal gate, and the dielectric cut pattern, an opening in the patterned mask layer exposing a portion of the first metal gate, a portion of the second metal gate, and a portion of the dielectric cut pattern underlying the opening; filling the opening with a first electrically conductive material; and recessing the first electrically conductive material below an upper surface of the dielectric cut pattern.

Abstract: A method for fabricating a vertical transistor device includes forming a plurality of fins on a substrate. The method further includes forming an interlevel dielectric layer on the substrate and sidewalls of each of the fins. The method further includes selectively removing the interlevel dielectric layer between adjacent fins. The method further includes laterally recessing a portion of the substrate between the adjacent fins to form a bottom source/drain cavity exposing a bottom portion of each fin and extending beyond each fin. The method further includes epitaxially growing an epitaxial growth material from the substrate and filling the bottom source/drain cavity.

Abstract: Methods of modifying the threshold voltage of metal oxide stacks are discussed. These methods utilize materials which provide larger shifts in threshold voltage while also being annealed at lower temperatures.

Abstract: A shadow mask used for OLED evaporation and a manufacturing method therefor, and an OLED panel manufacturing method. The shadow mask used for OLED evaporation includes: a semiconductor substrate including a front surface and a back surface opposite thereto, a recess penetrating the front surface and the back surface being provided in the semiconductor substrate; and a grid film layer provided on the front surface of the semiconductor substrate. A number of openings arranged in an array are provided in the grid film layer. Each of the openings has an upper portion and a lower portion. A width of the upper portion is greater than a width of the lower portion. The recess exposes the number of openings in the grid film layer and the grid film layer between adjacent openings.

Abstract: A method includes forming a first gate structure over a substrate, where the first gate structure is surrounded by a first dielectric layer; and forming a mask structure over the first gate structure and over the first dielectric layer, where forming the mask structure includes selectively forming a first capping layer over an upper surface of the first gate structure; and forming a second dielectric layer around the first capping layer. The method further includes forming a patterned dielectric layer over the mask structure, the patterned dielectric layer exposing a portion of the mask structure; removing the exposed portion of the mask structure and a portion of the first dielectric layer underlying the exposed portion of the mask structure, thereby forming a recess exposing a source/drain region adjacent to the first gate structure; and filling the recess with a conductive material.

Abstract: In an embodiment, a method includes: forming a first gate stack and a second gate stack on a fin; etching the fin to form a recess in the fin between the first gate stack and the second gate stack; forming an epitaxial source/drain region in the recess, the forming including: forming a first layer lining sides and a bottom of the recess by dispensing silane, dichlorosilane, trichlorosilane, and hydrochloric acid in the recess; and after forming the first layer, forming a second layer on the first layer by dispensing the silane, dichlorosilane, trichlorosilane, and hydrochloric acid in the recess, where each of the silane, dichlorosilane, trichlorosilane, and hydrochloric acid are dispensed at a first flow rate when forming the first layer and at a second flow rate when forming the second layer.

Abstract: Semiconductor devices and methods of forming the same are provided. The methods may implanting dopants into a substrate to form a preliminary impurity region and heating the substrate to convert the preliminary impurity region into an impurity region. Heating the substrate may be performed at an ambient temperature of from about 800° C. to about 950° C. for from about 20 min to about 50 min. The method may also include forming first and second trenches in the impurity region to define an active tin and forming a first isolation layer and a second isolation layer in the first and second trenches, respectively. The first and second isolation layers may expose opposing sides of the active fin. The method may further include forming a gate insulation layer extending on the opposing sides and an upper surface of the active fin and forming a gate electrode traversing the active fin.

Abstract: A method for forming a gaseous spacer in a semiconductor device and a semiconductor device including the gaseous spacer are disclosed. In an embodiment, the method may include forming a gate stack over a substrate, depositing a first gate spacer on sidewalls of the gate stack, epitaxially growing source/drain regions on opposite sides of the gate stack, and depositing a second gate spacer over the first gate spacer to form a gaseous spacer below the second gate spacer. The gaseous spacer may be disposed laterally between the source/drain regions and the gate stack.

Abstract: Disclosed is a light-emitting module including: a first insulation film having light transmissive property; a conductor layer provided on the first insulation film; a second insulation film disposed to face the first insulation film; a plurality of light-emitting elements interposed between the first insulation film and the second insulation film and have one surface on which a pair of electrodes connected to the conductor layer are provided; and a board that is connected to the first insulation film and has a circuit connected to the conductor layer.

Abstract: A semiconductor device includes: (i) a substrate; (ii) a first elongated semiconductor structure extending in a first horizontal direction along the substrate and protruding vertically above the substrate, wherein a first set of source/drain regions are formed on the first semiconductor structure; (iii) a second elongated semiconductor structure extending along the substrate in parallel to the first semiconductor structure and protruding vertically above the substrate, wherein a second set of source/drain regions are formed on the second semiconductor structure; and (iv) a first set of source/drain contacts formed on the first set of source/drain regions, wherein a first source/drain contact of the first set of source/drain contacts includes: (a) a vertically extending contact portion formed directly above a first source/drain region of the first set of source/drain regions, and (b) a via landing portion protruding horizontally from the vertically extending contact portion in a direction towards the second se

Abstract: Method for producing field-effect transistor including source electrode and drain electrode, gate electrode, active layer, and gate insulating layer, the method including etching the gate insulating layer, wherein the gate insulating layer is metal oxide including A-element and at least one selected from B-element and C-element, the A-element is at least one selected from Sc, Y, Ln (lanthanoid), Sb, Bi, and Te, the B-element is at least one selected from Ga, Ti, Zr, and Hf, the C-element is at least one selected from Group 2 elements in periodic table, etching solution A is used when at least one selected from the source electrode and the drain electrode, the gate electrode, and the active layer is formed, and etching solution B that is etching solution having same type as the etching solution A is used when the gate insulating layer is etched.

Abstract: Various methods and structures for fabricating a contact for a semiconductor FET or FinFET device. A semiconductor FET structure includes a substrate, a source/drain region layer and source/drain contact. First and second gate spacers are adjacent respective first and second opposing sides of the source/drain contact. The source/drain contact is disposed directly on and contacting the entire source/drain region layer, and at a vertical level thereabove, the source/drain contact being recessed to a limited horizontal area continuing vertically upwards from the vertical level. The limited horizontal area horizontally extending along less than a full horizontal length of a vertical sidewall of the first and second gate spacers, and less than fully covering the source/drain region layer. A method uses a reverse contact mask to form a shape of the source/drain contact into an inverted “T” shape.

Abstract: A material layer having recesses is formed on a substrate including a high pattern density area and a low pattern density area. A first dielectric layer and a second dielectric layer are sequentially formed to cover the material layer, wherein a top surface of the first dielectric layer in the high pattern density area is higher than a top surface of the first dielectric layer in the low pattern density area, thereby a thickness of the second dielectric layer in the low pattern density area being thicker than a thickness of the second dielectric layer in the high pattern density area. An etching back process is performed to remove the second dielectric layer and the first dielectric layer, wherein the etching rate of the etching back process to the second dielectric layer is lower than the etching rate of the etching back process to the first dielectric layer.

Abstract: An integrated circuit structure includes a gate stack over a semiconductor substrate, and a silicon germanium region extending into the semiconductor substrate and adjacent to the gate stack. The silicon germanium region has a top surface, with a center portion of the top surface recessed from edge portions of the top surface to form a recess. The edge portions are on opposite sides of the center portion.

Abstract: Semiconductor structures and fabrication methods are provided. An exemplary fabrication method includes providing at least one fin on a semiconductor substrate; forming a stacked channel layer having at least one sacrificial layer on the fin and a channel layer on the sacrificial layer; forming a dummy gate structure on the stacked channel layer; forming openings in the stacked channel layer at both sides of the dummy gate structure; removing portions of the sacrificial layer under the dummy gate structure to form grooves on sidewall surfaces of the openings; and forming a protective layer in the grooves.

Abstract: Structures and formation methods of a semiconductor device structure are provided. The semiconductor device structure includes a substrate, a dielectric layer over the substrate, a first metal gate structure in the dielectric layer and having a first width and a second metal gate structure in the dielectric layer and having a second width. The first metal gate structure includes a first metal electrode, and the second metal gate structure includes a second metal electrode. The second metal electrode includes a first conductive portion having a third width and a second conductive portion over the first conductive portion and having a fourth width. The fourth width is greater than the third width. The semiconductor device structure also includes two first source/drain portions at opposite sides of the first metal gate structure, and two second source/drain portions at opposite sides of the second metal gate structure.

Abstract: A method of forming a fin field effect transistor (finFET) having fin(s) with reduced dimensional variations, including forming a dummy fin trench within a perimeter of a fin pattern region on a substrate, forming a dummy fin fill in the dummy fin trench, forming a plurality of vertical fins within the perimeter of the fin pattern region, including border fins at the perimeter of the fin pattern region and interior fins located within the perimeter and inside the bounds of the border fins, wherein the border fins are formed from the dummy fin fill, and removing the border fins, wherein the border fins are dummy fins and the interior fins are active vertical fins.

Abstract: A semiconductor device includes a substrate including a first region and a second region, a first transistor and a second transistor formed in the first region and second region, respectively, wherein the first transistor includes a thick gate insulating layer and a thin buffer insulating layer formed in the substrate, a first gate electrode formed on the thick gate insulating layer, a first spacer formed on the thin buffer insulating layer, and a source region and a drain region formed in the substrate.

Abstract: Integrated circuit devices are provided. An integrated circuit device includes a substrate having first and second fin-shaped Field Effect Transistor (FinFET) bodies protruding from the substrate. The first and second FinFET bodies have different respective first and second shapes in a first region and a second region, respectively, of the integrated circuit device.

Abstract: A semiconductor device structure and method for forming the same are provided. The semiconductor device structure includes a substrate and a gate stack structure formed on the substrate. The semiconductor device structure also includes gate spacers formed on the sidewall of the gate stack structure, and the gate spacers include a top portion and a bottom portion adjoined to the top portion, and the bottom portion slopes to a top surface of the substrate. The semiconductor device structure further includes an epitaxial structure formed adjacent to the gate spacers, and the epitaxial structure is formed below the gate spacers.

Abstract: A polysilicon layer is formed over a substrate. The polysilicon layer is etched to form a dummy gate electrode having a top portion with a first lateral dimension and a bottom portion with a second lateral dimension. The first lateral dimension is greater than, or equal to, the second lateral dimension. The dummy gate electrode is replaced with a metal gate electrode.

Abstract: Disclosed are a pixel unit, an array substrate and a manufacturing method therefor, a display panel and a display device. At least two step portions adjacent to each other in an upward direction are provided at at least one of a first side of a drain electrode close to a display region and a second side of the drain electrode away from the display region, such that a pixel electrode is lapped onto the drain electrode gently.

Abstract: A semiconductor device according to an embodiment includes a first electrode; a second electrode; a silicon carbide layer disposed between the first electrode and the second electrode; an n-type silicon carbide region disposed in the silicon carbide layer and having a first nitrogen concentration; a first p-type silicon carbide region disposed in the silicon carbide layer between the n-type silicon carbide region and the first electrode and having a second nitrogen concentration higher than the first nitrogen concentration; and a second p-type silicon carbide region disposed in the silicon carbide layer between the first p-type silicon carbide region and the first electrode, having a third nitrogen concentration higher than the second nitrogen concentration, and having a p-type impurity concentration higher than that of the first p-type silicon carbide region.

Abstract: A CMOS device includes a p-type field effect transistor containing p-doped active regions, an n-type field effect transistor containing n-doped active regions, a silicon oxide layer overlying the n-type field effect transistor and not overlying the p-type field effect transistor, boron-doped epitaxial pillar structures contacting a top surface of, and epitaxially aligned to, a respective one of the p-doped active regions, first active region contact via structures contacting a top surface of a respective one of the boron-doped epitaxial pillar structures, and second active region contact via structures contacting a top surface of a respective one of the n-doped active regions.

Abstract: A method for fabricating a semiconductor device includes forming a pellicle including an amorphous carbon layer, attaching the pellicle onto a reticle, and forming a photoresist pattern by utilizing EUV light transmitted through the pellicle and reflected by the reticle. The forming the pellicle includes forming a first dielectric layer on a first side of the substrate, forming the amorphous carbon layer on the first dielectric layer, forming a second dielectric layer on a second side of the substrate opposite to the first side of the substrate, etching the second dielectric layer overlapping the first region of the substrate to form a mask pattern, and forming a support including the second region of the substrate and the remaining part of the first dielectric layer. The forming the support includes etching the first region of the substrate and the first dielectric layer on the first region.

Abstract: A semiconductor device is provided that includes a first plurality of fin structures having a first width in a first region of a substrate, and a second plurality of fin structures having a second width in a second region of the substrate, the second width being less than the first width. A first gate structure is formed on the first plurality of fin structures including a first high-k gate dielectric that is in direct contact with a channel region of the first plurality of fin structures and a first gate conductor. A second gate structure is formed on the second plurality of fin structures including a high voltage gate dielectric that is in direct contact with a channel region of the second plurality of fin structures, a second high-k gate dielectric and a second gate conductor.

Abstract: By decoupling the formation of a metal silicide in the gate electrode structure and the raised drain and source regions, superior flexibility in designing transistor elements and managing overall process flow may be achieved. To this end, the metal silicide in the gate electrode structures may be formed prior to actually patterning the gate electrode structures, while, also during this process sequence, a mask material may be applied for reliably covering any device regions in which a silicidation is not required. Consequently, superior gate conductivity may be accomplished, without increasing the risk of silicide penetration into the channel region of sophisticated fully depleted SOI transistors.

Abstract: The invention relates to a method for forming a field effect transistor. The method comprises providing a substrate with a channel layer, forming a gate stack structure on the channel layer, forming first sidewall spacers, forming a raised source and a raised drain on the channel layer and forming second sidewall spacers above the raised source and the raised drain. The method further includes depositing in a an insulating dielectric layer above the gate stack structure, the first sidewall spacers and the second sidewall spacers, planarization of the insulating dielectric layer and selectively etching the second sidewall spacers. Thereby contact cavities are created on the raised source and the raised drain. The method further includes forming a source contact and a drain contact by filling the contact cavities. The invention also concerns a corresponding computer program product.

Abstract: A vertical transistor has a first air-gap spacer between a gate and a bottom source/drain region, and a second air-gap spacer between the gate and the contact to the bottom source/drain region. A dielectric layer disposed between the gate and the contact to the top source/drain decreases parasitic capacitance and inhibits electrical shorting.

Abstract: In a manufacturing method of a semiconductor device according to an embodiment, an oxide film is formed on a semiconductor layer containing an impurity. A heat treatment is performed on the semiconductor layer to diffuse part of the impurity into the oxide film with hydrogen plasma treatment on the oxide film or with ultraviolet irradiation on the oxide film. After the heat treatment, the oxide film is removed.

Abstract: Embodiments of the present disclosure generally relate to methods for forming a doped silicon epitaxial layer on semiconductor devices at increased pressure and reduced temperature. In one embodiment, the method includes heating a substrate disposed within a processing chamber to a temperature of about 550 degrees Celsius to about 800 degrees Celsius, introducing into the processing chamber a silicon source comprising trichlorosilane (TCS), a phosphorus source, and a gas comprising a halogen, and depositing a silicon containing epitaxial layer comprising phosphorus on the substrate, the silicon containing epitaxial layer having a phosphorus concentration of about 1×1021 atoms per cubic centimeter or greater, wherein the silicon containing epitaxial layer is deposited at a chamber pressure of about 150 Torr or greater.

Abstract: A semiconductor structure is provided that includes a semiconductor fin portion having an end wall and extending upward from a substrate. A gate structure straddles a portion of the semiconductor fin portion. A first set of gate spacers is located on opposing sidewall surfaces of the gate structure; and a second set of gate spacers is located on sidewalls of the first set of gate spacers. One gate spacer of the second set of gate spacers has a lower portion that directly contacts the end wall of the semiconductor fin portion.

Abstract: A semiconductor structure is provided that includes a semiconductor fin portion having an end wall and extending upward from a substrate. A gate structure straddles a portion of the semiconductor fin portion. A first set of gate spacers is located on opposing sidewall surfaces of the gate structure; and a second set of gate spacers is located on sidewalls of the first set of gate spacers. One gate spacer of the second set of gate spacers has a lower portion that directly contacts the end wall of the semiconductor fin portion.

Abstract: There is provided a method for manufacturing a transistor including a gate above an underlying layer of a semiconductor material and including at least one first flank and one second flank, a gate foot formed in the underlying layer, a peripheral portion of the underlying layer surrounding the gate foot, and spacers covering at least partially the first and second flanks so as to not cover the gate foot; the method including forming the underlying layer by partially removing the semiconductor material around the gate to form the gate foot and the peripheral portion; then forming a dielectric layer for forming spacers by a deposition to cover both the first and second flanks, the gate foot, and an upper surface of the peripheral portion; and then partially removing the dielectric layer so as to expose the upper surface and so as to not expose the first and second flanks.

Abstract: A method for fabricating semiconductor device is disclosed. First, a substrate is provided, a gate structure is formed on the substrate, a recess is formed adjacent to the gate structure, a buffer layer is formed in the recess, and an epitaxial layer is formed on the buffer layer. Preferably, the buffer layer includes a crescent moon shape.

Abstract: A method includes forming a metallic layer over a Metal-Oxide-Semiconductor (MOS) device, forming reverse memory posts over the metallic layer, and etching the metallic layer using the reverse memory posts as an etching mask. The remaining portions of the metallic layer include a gate contact plug and a source/drain contact plug. The reverse memory posts are then removed. After the gate contact plug and the source/drain contact plug are formed, an Inter-Level Dielectric (ILD) is formed to surround the gate contact plug and the source/drain contact plug.

Abstract: A semiconductor device includes a substrate including a first fin element, a second fin element, and a third fin element. A first source/drain epitaxial feature is disposed over the first and second fin elements. A first portion of the first source/drain epitaxial feature disposed on the first fin element and a second portion of the first source/drain epitaxial feature disposed on the second fin element merge at a merge point. A second source/drain epitaxial feature is disposed over the third fin element. A first sidewall of the second source/drain epitaxial feature interfaces a first third-fin spacer disposed along a first sidewall of the third fin element. A second sidewall of the second source/drain epitaxial feature interfaces a second third-fin spacer disposed along a second sidewall of the third fin element. The merge point has a first height less than a second height of the first third-fin spacer.