Abstract: A semiconductor memory device includes a bit line, a common source pattern above the bit line, a channel layer in contact with the common source pattern, the channel layer extending toward the bit line, and a filling insulating layer disposed between the bit line and the common source pattern, the filling insulating layer surrounding a first part of the channel layer. The semiconductor memory device also includes a gate stack structure disposed between the bit line and the filling insulating layer, the gate stack structure surrounding a second part of the channel layer. The semiconductor memory device further includes a first etch stop pattern on a sidewall of the filling insulating layer, a second etch stop pattern between the first etch stop pattern and the filling insulating layer, and a memory pattern between the gate stack structure and the channel layer.

Abstract: A nitride semiconductor device includes a channel layer, a barrier layer made of AlxInyGa1-x-yN (x>0, x+y?1), an active region that has a layered structure including the channel layer and the barrier layer, an inactive region that is formed at the layered structure around the active region and that is a concave portion having a bottom portion that reaches the channel layer, a gate layer made of a nitride semiconductor selectively formed on the barrier layer in the active region, a gate electrode formed on the gate layer, a first insulating film that covers the gate electrode and that is in contact with the barrier layer in the active region, and a second insulating film that covers the first insulating film and that is in contact with the inactive region.

Abstract: Transistors having nonplanar electron channels in the channel width plane have one or more features that cause the different parts of the nonplanar electron channel to turn on at substantially the same threshold voltage. Advantageously, such transistors have substantially uniform threshold voltage across the nonplanar electron channel. Devices, image sensors, and pixels incorporating such transistors are also provided, in addition to methods of manufacturing the same.

Abstract: A magnetoresistive random-access memory cell includes a templating layer. The templating layer includes a binary alloy having an alternating layer lattice structure. The cell further includes a half metallic half-Heusler layer including a half metallic half-Heusler material having a tetragonal lattice structure. The half metallic half-Heusler layer is located outward of the templating layer, and has a half-Heusler in-plane lattice constant that is different from an in-plane lattice constant in a cubic form of the half metallic half-Heusler material. A tunnel barrier is located outward of the half metallic half-Heusler layer, and a magnetic layer is located outward of the tunnel barrier.

Abstract: A semiconductor device includes a region of semiconductor material having a first side and a second side opposite to the first side. Active device structures are adjacent to the first side, the active device structures comprising source regions and gate electrodes. A first gate conductor is at the first side electrically connected to the gate electrodes, a drain region is at the second side, a second gate conductor is at the second side, and through-semiconductor vias extending from the first side towards the side and electrically connecting the first gate electrode to the second gate electrode. A source electrode is at the first side electrically connected to the source regions, and a drain electrode is at the second side electrically connected to the drain region. The through-semiconductor vias are electrically isolated from the source regions and the drain region. The structure provides a gate/drain up with a source-down configuration.

Abstract: A heat pipe is provided as an electrically inactive structure to dissipate heat that is generated by vertically stacked field effect transistors (FETs). The heat pipe is present in an electrically inactive device area which is located adjacent to an electrically active device area that includes the vertically stacked FETs. The heat pipe includes at least one vertical interconnect structure that continuously extends between each tier of the vertically stacked FETs.

Abstract: Various methods for fabricating non-planar integrated circuit devices, such as FinFET devices, are disclosed herein. An exemplary method includes forming a rib structure extending from a substrate; forming a two-dimensional material layer (including, for example, transition metal dichalcogenide or graphene) on the rib structure and the substrate; patterning the two-dimensional material layer, such that the two-dimensional material layer is disposed on at least one surface of the rib structure; and forming a gate on the two-dimensional material layer. In some implementations, a channel region, a source region, and a drain region are defined in the two-dimensional material layer. The channel region is disposed between the source region and the drain region, where the gate is disposed over the channel region. In some implementations, the patterning includes removing the two-dimensional material layer disposed on a top surface of the substrate and/or disposed on a top surface of the rib structure.

Abstract: Semiconductor devices having improved heat dissipation and methods of forming the same are disclosed. In an embodiment, a device includes a first transistor structure; a front-side interconnect structure on a front-side of the first transistor structure, the front-side interconnect structure including front-side conductive lines; a backside interconnect structure on a backside of the first transistor structure, the backside interconnect structure including backside conductive lines, the backside conductive lines having line widths greater than line widths of the front-side conductive lines; and a first heat dissipation substrate coupled to the backside interconnect structure.

Abstract: A semiconductor device includes: a gate trench formed into a semiconductor substrate; a gate dielectric layer formed in the gate trench to cover an inside surface of the gate trench; and a gate electrode disposed over the gate dielectric layer to fill the gate trench, wherein the gate electrode includes: second crystal grains formed in the gate trench; and first crystal grains disposed between the second crystal grains and the gate dielectric layer and having a smaller crystal grain size than the second crystal grains.

Abstract: A method of forming an electrical device that includes forming a multilayered fin composed of a first source/drain layer for a first transistor, a first channel layer for the first transistor, a common source/drain layer for the first transistor and a second transistor, a second channel layer for the second transistor and a second source/drain layer for the second transistor. A common spacer is formed on the common source/drain layer that separates a first opening to the first channel layer from a second opening to the second channel layer. Gate structures are then formed in the first and second openings.

Abstract: Systems, methods, circuits, and devices for providing and using transistors in a physically unclonable function (PUF) circuit. The transistors comprise a split source drain configuration including one or more inflection segments that increase process variations between the transistors such that each transistor generates a unique output signal.

Abstract: Power semiconductor devices comprise a gate pad, a plurality of gate fingers, and a first gate resistor and a first switch that are coupled between the gate pad and the gate fingers.

Abstract: A field-effect transistor includes a substrate, a source electrode, a drain electrode, a gate electrode, a gate-insulating film, and an active layer. The active layer contains an oxide having a transmittance of 70% or more in the wavelength range of 400 to 800 nm. A light-shielding member is provided as a light-shielding structure for the active layer, for example, on the bottom face of the substrate.

Abstract: Provided are a transistor array substrate and an electronic device. A first active layer includes a first area, a second area spaced apart from the first area, and a channel area provided between the first area and the second area. A gate insulating film is disposed on the first active layer. A gate electrode is disposed on the gate insulating film to overlap a portion of the channel area of the first active layer. The gate electrode overlaps a portion of at least one area of the first and second areas of the first active layer. Deteriorations in the channel area are prevented.

Abstract: Semiconductor devices are provided. A semiconductor device includes a fin structure having a plurality of first semiconductor patterns and a plurality of second semiconductor patterns alternately stacked on a substrate, and extending in a first direction. The semiconductor device includes a semiconductor cap layer on an upper surface of the fin structure, and extending along opposite side surfaces of the fin structure in a second direction crossing the first direction. The semiconductor device includes a gate electrode on the semiconductor cap layer, and extending in the second direction. The semiconductor device includes a gate insulating film between the semiconductor cap layer and the gate electrode. Moreover, the semiconductor device includes a source/drain region connected to the fin structure. The plurality of first semiconductor patterns include silicon germanium (SiGe) having a germanium (Ge) content in a range of 25% to 35%, and the plurality of second semiconductor patterns include silicon (Si).

Abstract: The present disclosure relates to a semiconductor device and a fabricating method thereof, which includes a substrate and a plurality of word lines. The substrate includes a shallow trench isolation and an active structure defined by the shallow trench isolation and the active structure includes a first active area and a second active area. The first active area includes a plurality of active area units being parallel extended along a first direction, and the second active area is disposed outside a periphery of the first active area, to surround all of the active area units. The word lines are disposed in the substrate to intersect the active area units and the shallow trench isolation. The word lines includes first word lines arranged by a first pitch and second word lines arranged by a second pitch, and the second pitch is greater than the first pitch.

Abstract: An active region has first and second cell regions respectively disposed in a main IGBT and a sensing IGBT. The second cell region has a detecting region in which the sensing IGBT is disposed and an extracting region that surrounds a periphery of the detecting region. A resistance region containing polysilicon and connected to the sensing IGBT is provided on the semiconductor substrate, in the extracting region. The resistance region connected to the sensing IGBT has a first portion connected to the gate electrodes of the sensing IGBT and a second portion connecting the first portion to the gate runner, and configures a built-in resistance of the second portion having a resistance value in a range from 10? to 5000?. As a result, a trade-off relationship between enhancing ESD tolerance of a current sensing region that includes the sensing IGBT and reducing transient sensing voltage may be improved.

Abstract: According to one embodiment, a semiconductor device includes: a first well region of N-type and a second well region of P-type; a PMOS transistor provided in the first well region; and an NMOS transistor provided in the second well region. The PMOS transistor includes a first gate insulating layer and a first gate electrode. The NMOS transistor includes a second gate insulating layer and a second gate electrode. The first gate electrode includes a first semiconductor layer of P-type, a first insulating layer, and a first conductive layer. The second gate electrode includes a second semiconductor layer of N-type, a second insulating layer, and a second conductive layer. A film thickness of the first insulating layer is thicker than a film thickness of the second insulating layer.

Abstract: In some embodiments, the present disclosure relates to an integrated chip that includes a gate electrode arranged over a substrate. A gate dielectric layer is arranged over the gate electrode, and an active structure is arranged over the gate dielectric layer. A source contact and a drain contact are arranged over the active structure. The active structure includes a stack of cocktail layers alternating with first active layers. The cocktail layers include a mixture of a first material and a second material. The first active layers include a third material that is different than the first and second materials. The bottommost layer of the active structure is one of the cocktail layers.

Abstract: There are provided a variable resistance memory device and a manufacturing method of the same. The variable resistance memory device includes: a first electrode; a second electrode arranged in a vertical direction from the first electrode; and an oxide layer having an oxygen deficient region extending in the vertical direction between the second electrode and the first electrode.

Abstract: An open circuit voltage photodetector comprises a photovoltaic device including a photovoltaic junction, and a transistor. The photovoltaic device is connected to the gate terminal of the transistor to input an open circuit voltage of the photovoltaic device to the gate terminal. An array of such photodetectors and a readout integrated circuit forms an image sensor. In a photodetection method, an open circuit voltage is generated in a photovoltaic device in response to illumination by incident radiation, and the open circuit voltage is applied to a gate terminal of a transistor to modulate a channel current flowing in a channel of the transistor. A readout electronic circuit may be fabricated with an extra transistor, and a photovoltaic device disposed on the readout electronic circuit and electrically connected to apply an open circuit voltage of the photovoltaic device to a gate of the extra transistor.

Abstract: An organic light-emitting display panel and a display device are provided. The organic light-emitting display panel includes a control circuit. The control circuit includes a plurality of transistors. The plurality of transistors includes at least one first-type transistor, and each of the at least one first-type transistor has a channel width and a channel length, one of which is greater than five times the other one. Each of the at least one first-type transistor is a single-gate transistor.

Abstract: A semiconductor device includes a peripheral circuit structure disposed on a substrate; a lower stack disposed on the peripheral circuit structure and an upper stack disposed in the lower stack, the lower stack including a plurality of lower insulating layers and a plurality of lower word lines alternately stacked with the lower insulating layers; a plurality of channel structures extending through the lower stack and the upper stack in the cell array area; a pair of separation insulating layers extending vertically through the lower stack and the upper stack and extending in a horizontal direction, the pair of separation insulating layers being spaced apart from each other in a vertical direction; and a word line separation layer disposed at an upper portion of the lower stack and crossing the pair of separation insulating layers when viewed in a plan view, the word line separation layer extending vertically through at least one of the lower word lines.

Abstract: A method of fabricating an MRAM device, the method including forming a magnetoresistive random-access memory (MRAM) stack comprising a first hard mask, forming sidewall spacers adjacent to the MRAM stack, forming a layer of interconnect metal around and above the MRAM stack, recessing the interconnect metal, forming a layer of a second hard mask over the interconnect metal, and patterning and etching the second hard mask and interconnect metal, forming interconnect metal lines.

Abstract: A semiconductor memory device and a device including the same are provided. The semiconductor memory device includes word lines extending in a first direction on a semiconductor substrate; bit line structures extending across the word lines in a second direction crossing the first direction; contact pad structures between the word lines and between the bit line structures; and spacers between the bit line structures and the contact pad structures. The spacers include a boron nitride layer.

Abstract: A semiconductor device includes: a gate trench formed into a semiconductor substrate; a gate dielectric layer formed in the gate trench to cover an inside surface of the gate trench; and a gate electrode disposed over the gate dielectric layer to fill the gate trench, wherein the gate electrode includes: second crystal grains formed in the gate trench; and first crystal grains disposed between the second crystal grains and the gate dielectric layer and having a smaller crystal grain size than the second crystal grains.

Abstract: Provided are memristors and neuromorphic devices including the memristors. A memristor includes a lower electrode and an upper electrode that are apart from each other and first and second two-dimensional material layers that are arranged between the lower electrode and the upper electrode and stacked without a chemical bond therebetween.

Abstract: Ion-doped two-dimensional nanomaterials are made by inducing electronic carriers (electrons and holes) in a two-dimensional material using a captured ion layer at the surface of the material. The captured ion layer is stabilized using a capping layer. The induction of electronic carriers works in atomically-thin two-dimensional materials, where it induces high carrier density of at least 1014 carriers/cm2. A variety of novel ion-doped nanomaterials and p-n junction-based nanoelectronic devices are made possible by the method.

Abstract: Transistor structures and methods of forming transistor structures are provided. The transistor structures include alternating layers of a first epitaxial material and a second epitaxial material. In some embodiments, one of the first epitaxial material and the second epitaxial material may be removed for one of an n-type or p-type transistor. A bottommost layer of the first epitaxial material and the second epitaxial material maybe be removed, and sidewalls of one of the first epitaxial material and the second epitaxial material may be indented or recessed.

Abstract: A multilayer semiconductor on insulator structure is provided in which the handle substrate and an epitaxial layer in interfacial contact with the handle substrate comprise electrically active dopants of opposite type. The epitaxial layer is depleted by the handle substrate free carriers, thereby resulting in a high apparent resistivity, which improves the function of the structure in RF devices.

Abstract: A silicon carbide substrate has a first main surface and a second main surface opposite to the first main surface. A gate pad faces the first main surface. A drain electrode is in contact with the second main surface. The silicon carbide substrate includes a first impurity region constituting the second main surface and having a first conductivity type, a second impurity region provided on the first impurity region and having a second conductivity type different from the first conductivity type, a third impurity region provided on the second impurity region and having the first conductivity type, and a fourth impurity region provided on the third impurity region, constituting the first main surface, and having the second conductivity type. Each of the first impurity region, the second impurity region, the third impurity region, and the fourth impurity region is located between the gate pad and the drain electrode.

Abstract: An image sensor device is provided. The image sensor device includes a substrate. The image sensor device includes a light-sensing region in the substrate. The image sensor device includes an isolation structure in the substrate. The isolation structure surrounds the light-sensing region. The image sensor device includes a grid layer over the substrate. The grid layer is over the isolation structure. The image sensor device includes a first lens over the light-sensing region and surrounded by the grid layer. The image sensor device includes a color filter layer over and in direct contact with the first lens. The image sensor device includes a second lens over the color filter layer.

Abstract: Semiconductor devices are provided. A semiconductor device includes a fin structure having a plurality of first semiconductor patterns and a plurality of second semiconductor patterns alternately stacked on a substrate, and extending in a first direction. The semiconductor device includes a semiconductor cap layer on an upper surface of the fin structure, and extending along opposite side surfaces of the fin structure in a second direction crossing the first direction. The semiconductor device includes a gate electrode on the semiconductor cap layer, and extending in the second direction. The semiconductor device includes a gate insulating film between the semiconductor cap layer and the gate electrode. Moreover, the semiconductor device includes a source/drain region connected to the fin structure. The plurality of first semiconductor patterns include silicon germanium (SiGe) having a germanium (Ge) content in a range of 25% to 35%, and the plurality of second semiconductor patterns include silicon (Si).

Abstract: Some embodiments include methods of forming semiconductor constructions. Alternating layers of n-type doped material and p-type doped material may be formed. The alternating layers may be patterned into a plurality of vertical columns that are spaced from one another by openings. The openings may be lined with tunnel dielectric, charge-storage material and blocking dielectric. Alternating layers of insulative material and conductive control gate material may be formed within the lined openings. Some embodiments include methods of forming NAND unit cells. Columns of alternating n-type material and p-type material may be formed. The columns may be lined with a layer of tunnel dielectric, a layer of charge-storage material, and a layer of blocking dielectric. Alternating layers of insulative material and conductive control gate material may be formed between the lined columns. Some embodiments include semiconductor constructions, and some embodiments include NAND unit cells.

Abstract: A channel all-around semiconductor device and a method of manufacturing the same are provided. The semiconductor device includes a plurality of gate structures and a multi-connected channel layer. The gate structures have the same extension direction, and each of the gate structures has opposite first end and second end. The gate structures are all surrounded by the multi-connected channel layer, and the plane direction of the multi-connected channel layer is perpendicular to the above extension direction, so that the channels of the gate structures are connected to each other.

Abstract: A sacrificial gate stack for forming a nanosheet transistor includes a substrate. first, second and third silicon channel nanosheets formed over the substrate, and a first sandwich of germanium (Ge) containing layers disposed between the substrate and first silicon channel nanosheet. The stack also includes a second sandwich of Ge containing layers disposed between the first silicon channel nanosheet and the second silicon channel nanosheet; and a third sandwich of Ge containing layers disposed between the second silicon channel nanosheet and the third silicon channel nanosheet. Each sandwich includes first and second low Ge containing layers surrounding a silicon germanium (SiGe) sacrificial nanosheet that has a higher Ge concentration than the first and second low Ge containing layers.

Abstract: A semiconductor device that can have favorable electrical characteristics and can be highly integrated is provided. The semiconductor device includes a first insulator; a second insulator over the first insulator; an oxide over the second insulator; a first conductor and a second conductor over the oxide; a third insulator over the oxide; a third conductor positioned over the third insulator and overlapping with the oxide; a fourth insulator in contact with the second insulator, a side surface of the oxide, a side surface of the first conductor, a top surface of the first conductor, a side surface of the second conductor, a top surface of the second conductor, and a side surface of the third insulator; and a fifth insulator in contact with a top surface of the third insulator and a top surface of the third conductor, and a top surface of the fourth insulator is in contact with the fifth insulator.

Abstract: A method of making a semiconductor device includes depositing an isolation region between adjacent fins of a plurality of fins over a substrate, wherein a top-most surface of the isolation region is a first distance from a bottom of the substrate. The method further includes doping each of the plurality of fins with a first dopant having a first dopant type to define a first doped region in each of the plurality of fins, wherein a bottom-most surface of the first doped region is a second distance from the bottom of the substrate, and the second distance is greater than the first distance. The method further includes doping each of the plurality of fins with a second dopant having a second dopant type to define a second doped region in each of the plurality of fins, wherein the second doped region contacts the isolation region.

Abstract: An integrated circuit can include a plurality of first transistors formed in a substrate and having gate lengths of less than one micron and at least one tipless transistor formed in the substrate and having a source-drain path coupled between a circuit node and a first power supply voltage. In addition or alternatively, an integrated circuit can include minimum feature size transistors; a signal driving circuit comprising a first transistor of a first conductivity type having a source-drain path coupled between a first power supply node and an output node, and a second transistor of a second conductivity type having a source-drain path coupled between a second power supply node and the output node, and a gate coupled to a gate of the first transistor, wherein the first or second transistor is a tipless transistor.

Abstract: According to one embodiment, a method includes performing a plasma etching process on a masked III-V semiconductor, and forming a passivation layer on etched portions of the III-V semiconductor. The passivation layer includes at least one of a group III element and/or a metal from the following: Ni, Cr, W, Mo, Pt, Pd, Mg, Ti, Zr, Hf, Y, Ta, and Sc.

Abstract: A sensing module is provided, including a sensing unit. The sensing unit is formed by a plurality of sensing pixels arranged in an array. Each of the plurality of sensing pixels includes a body and a sensing element. The sensing element is disposed on a bottom surface of the body. During sensing, a light may enter and pass through the bodies and be transmitted to the sensing elements. The sensing pixels are divided into at least a first group and a second group from a center of the array to a periphery of the array, and photon collection efficiency of sensing pixels in the first group is less than photon collection efficiency of sensing pixels in the second group. Meanwhile, a design method of a sensing module is also provided.

Abstract: In a method of manufacturing a semiconductor device, a first source/drain structure is formed over a substrate, one or more first insulating layers are formed over the first source/drain structure, a first opening is formed in the one or more first insulating layers, the first opening is filled with a first conductive material to form a first lower contact in contact with the first source/drain structure, one or more second insulating layers are formed over the first lower contact, a second opening is formed in the one or more second insulating layers to at least partially expose the first lower contact, a first liner layer is formed on at least a part of an inner side face of the second opening, and the second opening is filled with a second conductive material to form a first upper contact in contact with the first lower contact without the first liner layer.

Abstract: A 3D semiconductor device, the device including: a first level including a single crystal layer and a plurality of first transistors; a first metal layer including interconnects between the plurality of first transistors, where the interconnects between the plurality of first transistors includes forming a plurality of logic gates; a plurality of second transistors atop at least a portion of the first metal layer, where at least six of the plurality of first transistors are connected in series forming at least a portion of a NAND logic structure, where the plurality of second transistors are vertically oriented transistors, and where the plurality of second transistors are at least partially directly atop of the NAND logic structure; and a second metal layer atop at least a portion of the plurality of second transistors, where the second metal layer is aligned to the first metal layer with less than 150 nm misalignment, and where at least one of the second transistors is a junction-less transistor.

Abstract: A nano-crystalline high-k film and methods of forming the same in a semiconductor device are disclosed herein. The nano-crystalline high-k film may be initially deposited as an amorphous matrix layer of dielectric material and self-contained nano-crystallite regions may be formed within and suspended in the amorphous matrix layer. As such, the amorphous matrix layer material separates the self-contained nano-crystallite regions from one another preventing grain boundaries from forming as leakage and/or oxidant paths within the dielectric layer. Dopants may be implanted in the dielectric material and crystal phase of the self-contained nano-crystallite regions maybe modified to change one or more of the permittivity of the high-k dielectric material and/or a ferroelectric property of the dielectric material.

Abstract: A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, and memory stack structures extending through the alternating stack. Each of the memory stack structures includes a vertical stack of single crystalline ferroelectric dielectric layers and a respective vertical semiconductor channel.

Abstract: Provided are a complementary carbon nanotube field effect transistor (CNT-FET) and a manufacturing method thereof. In particular, provided is carbon nanotube-based type conversion technology (p-type?n-type) using a photosensitive polyvinyl alcohol polymer which can be selectively cross-linked at a desired position based on a semiconductor standard process, i.e., photolithography.

Abstract: A semiconductor device according to an example embodiment includes a substrate extending in first and second directions intersecting with each other; nanowires on the substrate and spaced apart from each other in the second direction; gate electrodes extending in the first direction and spaced apart from each other in the second direction, and surrounding the nanowires to be superimposed vertically with the nanowires; external spacers on the substrate and covering sidewalls of the gate electrodes on the nanowires; and an isolation layer between the gate electrodes and extending in the first direction, wherein an upper surface of the isolation layer is flush with upper surfaces of the gate electrodes.

Abstract: Embodiments of the present disclosure relate to the field of electronic sensing technologies, and provide a chemical sensing unit, a chemical sensor, and a chemical sensing device. The chemical sensing unit includes a thin film transistor arranged on a substrate, and a light emitting diode coupled to the thin film transistor. The thin film transistor includes a semiconductor active layer, a source, and a drain, and the semiconductor active layer is mainly composed of a chemically sensitive semiconductor material. The chemical sensing unit is provided with a via hole in a region between the source and the drain, such that the semiconductor active layer is exposed at a position corresponding to the via hole. The light emitting diode includes a first electrode, a light-emitting functional layer, and a second electrode which are stacked in sequence, wherein the first electrode is coupled to the drain.

Abstract: Structures and methods of forming self-aligned unsymmetric gate (SAUG) FinFET are provided. The SAUG FinFET structure has two different gate structures on opposite sides of each fin: a programming gate structure and a switching gate structure. The SAUG FinFET may be used as non-volatile memory (NVM) storage element that may be electrically programmed by trapping charges in the charge trapping dielectric (e.g., Si3N4) with appropriate bias on the control gate of the programming gate structure. The stored data may be sensed by sensing the channel current through the SAUG FinFET in response to a bias on the switching gate of the switching gate structure.

Abstract: A method of fabricating a vertical fin field effect transistor with a merged top source/drain, including, forming a source/drain layer at the surface of a substrate, forming a plurality of vertical fins on the source/drain layer; forming protective spacers on each of the plurality of vertical fins, forming a sacrificial plug between two protective spacers, forming a filler layer on the protective spacers not in contact with the sacrificial plug, and selectively removing the sacrificial plug to form an isolation region trench between the two protective spacers.