Abstract: A semiconductor structure is provided that contains silicon fins having different heights, while maintaining a reasonable fin height to width ratio for process feasibility. The semiconductor structure includes a first silicon fin of a first height and located on a pedestal portion of a first oxide structure. The structure further includes a second silicon fin of a second height and located on a pedestal portion of a second oxide structure. The first oxide structure and the second oxide structure are interconnected and the second oxide structure has a bottommost surface that is located beneath a bottommost surface of the first oxide structure. Further, the second height of the second silicon fin is greater than the first height of the first silicon fin, yet a topmost surface of the first silicon fin is coplanar with a topmost surface of the second silicon fin.

Abstract: A method of forming a semiconductor structure comprises forming pools of acidic or basic material in a substrate structure. A resist is formed over the pools of acidic or basic material and the substrate structure. The acidic or basic material is diffused from the pools into portions of the resist proximal to the pools more than into portions of the resist distal to the pools. Then, the resist is exposed to a developer to remove a greater amount of the resist portions proximal to the pools compared to the resist portions distal to the pools to form openings in the resist. The openings have wider portions proximal to the substrate structure and narrower portions distal to the substrate structure. The method may further comprise forming features in the openings of the resist. The features have wider portions proximal to the substrate structure and narrower portions distal to the substrate structure.

Abstract: Techniques are disclosed for heteroepitaxial growth of a layer of lattice-mismatched semiconductor material on an initial substrate, and transfer of a defect-free portion of that layer to a handle wafer or other suitable substrate for integration. In accordance with some embodiments, transfer may result in the presence of island-like oxide structures on the handle wafer/substrate, each having a defect-free island of the lattice-mismatched semiconductor material embedded within its upper surface. Each defect-free semiconductor island may have one or more crystalline faceted edges and, with its accompanying oxide structure, may provide a planar surface for integration. In some cases, a layer of a second, different semiconductor material may be heteroepitaxially grown over the handle wafer/substrate to fill areas around the transferred islands. In some other cases, the handle wafer/substrate itself may be homoepitaxially grown to fill areas around the transferred islands.

Abstract: A semiconductor device and a method for manufacturing the same are provided. A barrier film is formed in a device separating structure, and the device separating structure is etched at a predetermined thickness to expose a semiconductor substrate. Then, a SEG film is grown to form an active region whose area is increased. As a result, a current driving power of a transistor located at a cell region and peripheral circuit regions is improved.

Abstract: The present invention relates to a method for fabricating a substrate for a semiconductor device comprising an interface region between a first layer and a second layer having different electrical properties and an exposed surface, wherein at least the second layer includes defects and/or dislocations, the method comprising the steps of: a) removing material at one or more locations of the defects and/or dislocations, thereby forming pits, wherein the pits intersect the interface region, and b) passivating the pits. The invention also relates to a corresponding semiconductor device structure.

Abstract: A silicon device includes an active silicon layer, a buried oxide (BOX) layer beneath the active silicon layer and a high-resistivity silicon layer beneath the BOX layer. The device also includes a harmonic suppression layer at a boundary of the BOX layer and the high-resistivity silicon layer.

Abstract: Semiconductor devices including porous low-k dielectric layers and fabrication methods are provided. A dielectric layer is formed on a substrate by introducing and polymerizing a main reaction gas on a surface of the substrate. The main reaction gas has a chemical structure including a ring-shaped group, silicon, carbon, and hydrogen, and the ring-shaped group includes at least carbon and hydrogen. A porous low-k dielectric layer is then formed from the dielectric layer by curing the dielectric layer with UV light.

Abstract: A semiconductor structure includes: a substrate with at least a trench therein, wherein the trench is filled with an insulation layer; a first polysilicon layer disposed on the insulation layer and covering at least two opposite borders of a top surface of the insulation layer; a second polysilicon layer disposed above the first polysilicon layer and the substrate; and a dielectric layer disposed between the first and second polysilicon layers, wherein the first and second polysilicon layers are respectively shaped as first and second strips.

Abstract: A semiconductor device which eliminates the need for high fillability through a simple process and a method for manufacturing the same. A high breakdown voltage lateral MOS transistor including a source region and a drain region is completed on a surface of a semiconductor substrate. A trench which surrounds the transistor when seen in a plan view is made in the surface of the semiconductor substrate. An insulating film is formed over the transistor and in the trench so as to cover the transistor and form an air-gap space in the trench. Contact holes which reach the source region and drain region of the transistor respectively are made in an interlayer insulating film.

Abstract: A semiconductor device structure with an oxide-filled large deep trench (OFLDT) portion having trench size TCS and trench depth TCD is disclosed. A bulk semiconductor layer (BSL) is provided with a thickness BSLT>TCD. A large trench top area (LTTA) is mapped out atop BSL with its geometry equal to OFLDT. The LTTA is partitioned into interspersed, complementary interim areas ITA-A and ITA-B. Numerous interim vertical trenches of depth TCD are created into the top BSL surface by removing bulk semiconductor materials corresponding to ITA-B. The remaining bulk semiconductor materials corresponding to ITA-A are converted into oxide. If any residual space is still left between the so-converted ITA-A, the residual space is filled up with oxide deposition. Importantly, the geometry of all ITA-A and ITA-B should be configured simple and small enough to facilitate fast and efficient processes of oxide conversion and oxide filling.

Abstract: Disclosed herein is a fabrication method of a semiconductor device to order to increase an operation liability of the semiconductor device. A method for fabricating a semiconductor device comprises forming a recess in a semiconductor substrate, forming a word line in a lower part of the recess, oxidizing a top portion of the word line, and depositing an insulating material in a remained part of the recess.

Abstract: A method of producing a layer of cavities in a structure comprises at least one substrate formed from a material that can be oxidized or nitrided, the method comprising the following steps: implanting ions into the substrate in order to form an implanted ion concentration zone at a predetermined mean depth; heat treating the implanted substrate to form a layer of cavities at the implanted ion concentration zone; and forming an insulating layer in the substrate by thermochemical treatment from one surface of the substrate, the insulating layer that is formed extending at least partially into the layer of cavities.

Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes an element region, a gate insulating film, a first gate electrode, an intergate insulating film, a second gate electrode and an element isolation region. The gate insulating film is formed on the element region. The first gate electrode is formed on the gate insulating film. The intergate insulating film is formed on the first gate electrode and has an opening. The second gate electrode is formed on the intergate insulating film and in contact with the first gate electrode via the opening. The element isolation region encloses a laminated structure formed by the element region, the gate insulating film, and the first gate electrode. The air gap is formed between the element isolation region and side surfaces of the element region, the gate insulating film and the first gate electrode.

Abstract: A semiconductor product has different active thicknesses of silicon on a single semiconductor substrate. The thickness of the silicon layer is changed either by selectively adding silicon or subtracting silicon from an original layer of silicon. The different active thicknesses are suitable for use in different types of devices, such as diodes and transistors.

Abstract: Oxidation methods and resulting structures including providing an oxide layer on a substrate and then reoxidizing the oxide layer by vertical ion bombardment of the oxide layer in an atmosphere containing at least one oxidant. The oxide layer may be provided over diffusion regions, such as source and drain regions, in a substrate. The oxide layer may overlie the substrate and is proximate a gate structure on the substrate. The at least one oxidant may be oxygen, water, ozone, or hydrogen peroxide, or a mixture thereof. These oxidation methods provide a low-temperature oxidation process, less oxidation of the sidewalls of conductive layers in the gate structure, and less current leakage to the substrate from the gate structure.

Abstract: A gallium nitride-based semiconductor device includes a composite substrate and a gallium nitride layer. The composite substrate includes a silicon substrate and a filler. The silicon substrate includes a first surface and a second surface opposite to the first surface, and the first surface defines a number of grooves therein. The filler is filled into the number of grooves on the first surface of the silicon substrate. A thermal expansion coefficient of the filler is bigger than that of the silicon substrate. The gallium nitride layer is formed on the second surface of the silicon substrate.

Abstract: Provided is a method of manufacturing a semiconductor device. According to the method, a first buried oxide layer is formed in the semiconductor substrate in a first region, such that a first semiconductor layer is defined on the first buried oxide layer. An active portion is defined by forming a trench in the semiconductor substrate in a second region. A capping semiconductor pattern is formed on a top surface and an upper portion of a sidewall of the active portion. An oxide layer is formed by oxidizing the capping semiconductor pattern and an exposed lower portion of the sidewall of the active portion, such that the oxide layer surrounds a non-oxidized portion of the active portion. The non-oxidized portion of the active portion is a core and one end of the core is connected to a first optical device formed at the first semiconductor.

Abstract: The present invention is a method and an apparatus for optical modulation, for example for use in optical communications links. In one embodiment, an apparatus for optical modulation includes a first silicon layer having one or more trenches formed therein, a dielectric layer lining the first silicon layer, and a second silicon layer disposed on the dielectric layer and filling the trenches.

Abstract: A semiconductor device which eliminates the need for high fillability through a simple process and a method for manufacturing the same. A high breakdown voltage lateral MOS transistor including a source region and a drain region is completed on a surface of a semiconductor substrate. A trench which surrounds the transistor when seen in a plan view is made in the surface of the semiconductor substrate. An insulating film is formed over the transistor and in the trench so as to cover the transistor and form an air-gap space in the trench. Contact holes which reach the source region and drain region of the transistor respectively are made in an interlayer insulating film.

Abstract: This disclosure provides a method of fabricating a semiconductor stack and associated device, such as a capacitor and DRAM cell. In particular, a bottom electrode has a material selected for lattice matching characteristics. This material may be created from a relatively inexpensive metal oxide which is processed to adopt a conductive, but difficult-to-produce oxide state, with specific crystalline form; to provide one example, specific materials are disclosed that are compatible with the growth of rutile phase titanium dioxide (TiO2) for use as a dielectric, thereby leading to predictable and reproducible higher dielectric constant and lower effective oxide thickness and, thus, greater part density at lower cost.

Abstract: A method is provided to fabricate a semiconductor device, where the method includes providing a substrate comprised of crystalline silicon; implanting a ground plane in the crystalline silicon so as to be adjacent to a surface of the substrate, the ground plane being implanted to exhibit a desired super-steep retrograde well (SSRW) implant doping profile; annealing implant damage using a substantially diffusionless thermal annealing to maintain the desired super-steep retrograde well implant doping profile in the crystalline silicon and, prior to performing a shallow trench isolation process, depositing a silicon cap layer over the surface of the substrate. The substrate may be a bulk Si substrate or a Si-on-insulator substrate. The method accommodates the use of an oxynitride gate stack structure or a high dielectric constant oxide/metal (high-K/metal) gate stack structure.

Abstract: Problems with a conventional mesa type semiconductor device, which are deterioration in a withstand voltage and occurrence of a leakage current caused by reduced thickness of an insulation film on an inner wall of a mesa groove corresponding to a PN junction, are solved using an inexpensive material, and a mesa type semiconductor device of high withstand voltage and high reliability is offered together with its manufacturing method. A stable protection film made of a thermal oxide film is formed on the inner wall of the mesa groove in the mesa type semiconductor device to cover and protect the PN junction, and an insulation film having negative electric charges is formed to fill a space in the mesa groove covered with the thermal oxide film so that an electron accumulation layer is not easily formed at an interface between an N? type semiconductor layer and the thermal oxide film.

Abstract: A method is provided to fabricate a semiconductor device, where the method includes providing a substrate comprised of crystalline silicon; implanting a ground plane in the crystalline silicon so as to be adjacent to a surface of the substrate, the ground plane being implanted to exhibit a desired super-steep retrograde well (SSRW) implant doping profile; annealing implant damage using a substantially diffusionless thermal annealing to maintain the desired super-steep retrograde well implant doping profile in the crystalline silicon and, prior to performing a shallow trench isolation process, depositing a silicon cap layer over the surface of the substrate. The substrate may be a bulk Si substrate or a Si-on-insulator substrate. The method accommodates the use of an oxynitride gate stack structure or a high dielectric constant oxide/metal (high-K/metal) gate stack structure.

Abstract: One aspect includes a semiconductor arrangement with a semiconductor body having a first surface. A buried material layer is in the semiconductor body, the buried material layer being arranged distant to the first surface. A monocrystalline semiconductor material is arranged between the material layer and the first surface, and a monocrystalline semiconductor material adjoins the material layer in a lateral direction of the semiconductor body.

Abstract: A method for making a semiconductor device by reshaping a silicon surface with a sacrificial layer is presented. In the present invention the steps of forming a sacrificial dielectric layer and removing the sacrificial dielectric layer are repeated multiple times in order to remove sharp edges from the silicon surface near the field oxides. Another aspect of the present invention includes making a MOSFET transistor that incorporates the forming and removing of multiple sacrificial layers into the process.

Abstract: An insulation structure is provided. The insulation structure includes a deep trench filled with silicon and disposed in a substrate, a first oxide layer serving as the insulation structure and disposed on the surface of the silicon in the deep trench, a first silicon layer disposed on the first oxide layer, a gate disposed on the first silicon layer and a shallow trench isolation adjacent to the deep trench.

Abstract: To make it possible to significantly suppress the leakage current in a semiconductor device having a capacitor structure using a dielectric film. There is provided a composite oxide dielectric which is mainly composed of Zr, Al and O, and which has a composition ratio of Zr and Al in a range of (1?x):x where 0.01?x?0.15, and has a crystal structure. When the dielectric is set to have the Al composition in the above described range and is crystallized, the relative dielectric constant of the dielectric can be significantly increased. When the dielectric is used as a dielectric film of a capacitor of a semiconductor device, the leakage current of the capacitor can be significantly reduced.

Abstract: It is an object of the present invention, in a case of using a conductive material as part of an electrode for an organic transistor, to provide an organic transistor having a structure whose characteristics are not controlled by the work function of the conductive material. Moreover, it is other objects of the present invention to provide an organic transistor having favorable carrier mobility and to provide an organic transistor which is excellent in durability. A composite layer containing an organic compound and an inorganic material is used for an electrode for an organic field effect transistor, that is, at least part of one of a source electrode and a drain electrode in the organic field effect transistor.

Abstract: A manufacturing method for a semiconductor-device isolation structure comprises providing a substrate with at least one shallow trench isolation structure, performing a salicide process that forms a recess on the surface of the shallow trench isolation structure, forming a cap film covering the substrate and filling the recess, performing an etching process to remove the cap film outside the recess, and forming a contact etch stop layer covering the substrate and filling the recess. Due to the filling recess with the cap film first, the contact etch stop layer covering the substrate and filling the recess does not have seams or voids.

Abstract: A method for fabricating a semiconductor device according to the present invention is a method for fabricating a semiconductor device including a substrate layer including a plurality of first regions each having an active region and a plurality of second regions each being provided between adjacent ones of the first region. The fabrication method includes an isolation insulation film formation step of forming an isolation insulation film in each of the second regions so that a surface of the isolation insulation film becomes at the same height as that of a surface of a gate oxide film covering the active region, a peeling layer formation step of forming a peeling layer by ion-implanting hydrogen into the substrate layer after the isolation insulation film formation step, and a separation step of separating part of the substrate layer along the peeling layer.

Abstract: A semiconductor structure for electronics or optoelectronics that includes successively a bulk substrate, an oxide layer and a semiconductor layer, wherein the oxide layer comprises regions of different thicknesses which are selectively controlled.

Abstract: Silicon wafers, are manufactured with which a desired strength and electric resistance of a semiconductor device can be obtained. A non-oxidizing heat treatment for oxygen out-diffusion is performed wherein the desired amount of oxygen is discharged from the surface layer of the silicon substrate. By this heat treatment for oxygen out-diffusion, a surface layer having a low oxygen content is formed on the silicon substrate, the heat treatment of the silicon substrate being performed through an oxide film.

Abstract: A semiconductor device may be fabricated according to a method that reduces stain difference of a passivation layer in the semiconductor device. The method may include forming top wiring patterns in a substrate, depositing a primary undoped silicate glass (USG) layer on the top wiring patterns to fill a gap between the top wiring patterns, and coating a SOG layer on the substrate on which the primary USG layer has been deposited. Next, the SOG layer on the surface of the substrate may be removed until the primary USG layer is exposed, and a secondary USG layer may be deposited on the substrate on which the primary USG layer has been exposed.

Abstract: Isolation regions for semiconductor substrates include dielectric-filled trenches and field oxide regions. Protective caps of dielectric materials dissimilar from the dielectric materials in the main portions of the trenches and field oxide regions may be used to protect the structures from erosion during later process steps. The top surfaces of the isolation structures are coplanar with the surface of the substrate. Field doping regions may be formed beneath the field oxide regions. To meet the demands of different devices, the isolation structures may have varying widths and depths.

Abstract: A layer system is described including a silicon layer and a passivation layer which is applied at least regionally to the silicon layer's surface, the passivation layer having a first, at least largely inorganic partial layer and a second partial layer, the second partial layer being made of an organic compound including silicon or containing such a material. In particular, the second partial layer is structured in the form of a “self-assembled monolayer.” Furthermore, a method is described for creating a passivation layer on a silicon layer, a first, inorganic partial layer being created on the silicon layer and a second partial layer, containing an organic compound including silicon or being made thereof, being created at least in certain areas on the first partial layer. Both partial layers form the passivation layer. The described layer system or the described method is particularly suited for creating self-supporting structures in silicon.

Abstract: Provided is a semiconductor device formed to an SOI substrate including a MOS transistor in which a parasitic MOS transistor is suppressed. The semiconductor device formed on the SOI substrate by employing a LOCOS process is structured such that a part of a polysilicon layer to becomes a gate electrode includes: a first conductivity type polysilicon region corresponding to a region of the silicon active layer which has a constant thickness and is to become a channel; and second conductivity type polysilicon regions corresponding to LOCOS isolation edges in each of which a thickness of the silicon active layer decreases.

Abstract: A thin-film circuit device includes a substrate and a thin-film circuit layer, disposed on the substrate, having an element region and a low-strength region. The element region includes thin-film elements. The low-strength region extends between an end portion of the thin-film circuit layer and the element region and has a mechanical strength less than that of the surroundings of the low-strength region.

Abstract: A method for fabricating a capacitor in a semiconductor device includes: forming a bottom electrode; forming a ZrxAlyOz dielectric layer on the bottom electrode using an atomic layer deposition (ALD) method, wherein the ZrxAlyOz dielectric layer comprises a zirconium (Zr) component, an aluminum (Al) component and an oxygen (O) component mixed in predetermined mole fractions of x, y and z, respectively; and forming a top electrode on the ZrxAlyOz dielectric layer.

Abstract: A method of manufacturing a metal-oxide-semiconductor (MOS) transistor device is disclosed. A gate dielectric layer is formed on an active area of a substrate. A gate electrode is patterned on the gate dielectric layer. The gate electrode has vertical sidewalls and a top surface. A liner is formed on the vertical sidewalls of the gate electrode. A nitride spacer is formed on the liner. An ion implanted is performed to form a source/drain region. After salicide process, an STI region that isolates the active area is recessed, thereby forming a step height at interface between the active area and the STI region. The nitride spacer is removed. A nitride cap layer that borders the liner is deposited. The nitride cap layer has a specific stress status.

Abstract: An electrical structure and method of forming. The method includes providing a semiconductor structure comprising a semiconductor substrate, a buried oxide layer (BOX) formed over the semiconductor substrate, and a silicon on insulator layer (SOI) formed over and in contact with the BOX layer. The SOI layer comprises shallow trench isolation (STI) structures formed between electrical devices. A first photoresist layer is formed over the STI structures and the electrical devices. Portions of said first photoresist layer, portions of the STI structures, and portions of the BOX layer are removed resulting in formed trenches. Ion implants are formed within portions of the semiconductor substrate. Remaining portions of the first photoresist layer are removed. A dielectric layer is formed over the electrical devices and within the trenches. A second photoresist layer is formed over the dielectric layer. Portions of the second photoresist layer are removed.

Abstract: An IGFET that minimizes the effect of the dislocation at the edge of the device region by displacing the lateral edges of the source and drain regions from the adjacent edge of the opening and the dislocation. This minimizes the lateral diffusion of the source and drain impurities and the formation of metal silicides into the dislocation region. The spacing of the lateral edges of the source and drain regions from the adjacent edge of the opening and the dislocation region is produced by providing additional lateral opposed second gate regions or oxide barrier layer extending from the oxide layer into the adjacent regions of the substrate region and the first gate region extending therebetween. Both the first gate region and the two second gate regions or barrier layer are used in the self-aligned processing of the source and drain regions. The first gate region defines the length of the channel, while the two opposed second gate regions or barrier layer define the width of the channel region.

Abstract: A semiconductor device and a method for manufacturing the same are provided. A barrier film is formed in a device separating structure, and the device separating structure is etched at a predetermined thickness to expose a semiconductor substrate. Then, a SEG film is grown to form an active region whose area is increased. As a result, a current driving power of a transistor located at a cell region and peripheral circuit regions is improved.

Abstract: Disclosed herein are embodiments of a semiconductor structure and an associated method of forming the semiconductor structure with shallow trench isolation structures having selectively adjusted reflectance and absorption characteristics in order to ensure uniform temperature changes across a wafer during a rapid thermal anneal and, thereby, limit variations in device performance. Also disclosed are embodiments of another semiconductor structure and an associated method of forming the semiconductor structure with devices having selectively adjusted reflectance and absorption characteristics in order to either selectively vary the performance of individual devices (e.g., to form devices with different threshold voltages (Vt) on the same wafer) and/or to selectively optimize the anneal temperature of individual devices (e.g., to ensure optimal activation temperatures for n-type and p-type dopants during anneals).

Abstract: A semiconductor device is formed with a lower field plate (32) and optional lateral field plates (34) around semiconductor (20) in which devices are formed, for example power FETs or other transistor or diode types. The semiconductor device is manufactured by forming trenches with insulated sidewalls, etching cavities (26) at the base of the trenches which join up and then filling the trenches with conductor (30).

Abstract: A method is provided for making a silicon-on-insulator substrate. Such method can include epitaxially growing a highly p-type doped silicon-containing layer onto a major surface of an underlying semiconductor region of a substrate. Subsequently, a non-highly p-type doped silicon-containing layer may be epitaxially grown onto a major surface of the p-type highly-doped epitaxial layer to cover the highly p-type doped epitaxial layer. The overlying non-highly p-type doped epitaxial layer can have a dopant concentration substantially lower than the dopant concentration of the highly p-type doped epitaxial layer. The substrate can then be processed to form a buried oxide layer selectively by oxidizing at least portions of the highly p-type doped epitaxial layer covered by the non-highly p-type doped epitaxial layer, the buried oxide layer separating the overlying monocrystalline semiconductor layer from the underlying semiconductor region.

Abstract: A manufacturing method for a semiconductor-device isolation structure comprises providing a substrate with at least one shallow trench isolation structure, performing a salicide process that forms a recess on the surface of the shallow trench isolation structure, forming a cap film covering the substrate and filling the recess, performing an etching process to remove the cap film outside the recess, and forming a contact etch stop layer covering the substrate and filling the recess. Due to the filling recess with the cap film first, the contact etch stop layer covering the substrate and filling the recess does not have seams or voids.

Abstract: Methods of forming areas of alternative material on crystalline semiconductor substrates, and structures formed thereby. Such areas of alternative material are suitable for use as active areas in MOSFETs or other electronic or opto-electronic devices.

Abstract: A method for forming a self-align insulation of a passing gate is disclosed. First, a substrate is provided. A deep trench filled with silicon material and a shallow trench isolation adjacent to the deep trench are formed in the substrate. A patterned pad oxide and a patterned hard mask are sequentially formed on the substrate. The patterned pad oxide and the patterned hard mask together define the opening of the deep trench. Then, an oxidation step is carried out to form a first oxide layer serving as the insulation of a passing gate on the top surface of the silicon material of the deep trench. Later, a first Si layer is formed to cover the first oxide layer. Afterwards, the hard mask is removed.

Abstract: A deep n-well is formed beneath the area of an inductor coil. The use of a deep n-well lessens the parasitic capacitance by placing a diode in series with the interlayer dielectric cap. The deep n-well also reduces substrate noise. Once the n-well is implanted and annealed, a cross hatch of shallow trench isolation is patterned over the n-well. The shallow trench isolation reduces and confines the inductively coupled surface currents to small areas that are then isolated from the rest of the chip.

Abstract: A method for fabricating an isolation structure in a memory device includes forming a first trench in a cell region of a semiconductor substrate and a second trench in a peripheral region of the semiconductor substrate. The method also includes oxidating the surface of the first and second trenches to form a sidewall oxide layer; depositing a tetraethylorthosilicate(TEOS) layer on the sidewall oxide layer; forming a silicon nitride layer and a silicon oxide layer on the TEOS layer; selectively removing portions of the silicon nitride and silicon oxide layers on the second trench to expose a portion of the underlying TEOS layer; coating a flowable insulation layer that fills the first and second trenches; and curing the flowable insulation layer.