Abstract: The present disclosure relates to an array substrate, a manufacturing method thereof, and a display panel, the array substrate including: a substrate, and a low temperature polysilicon layer, an inorganic film group layer, and a source/drain layer disposed on the substrate in sequence. The substrate includes a display region, the low temperature polysilicon layer located at the display region, the inorganic film group layer provided with a through hole, and an angle between a sidewall and a bottom wall of the through hole is not less than 100 degrees; the source/drain layer covering the sidewall and the bottom wall of the through hole to be connected to the low temperature polysilicon layer.

Abstract: A semiconductor package includes an encapsulated semiconductor device, a first redistribution structure, an insulating layer, and an antenna. The encapsulated semiconductor device includes a semiconductor device encapsulated by an encapsulation material. The redistribution structure is disposed on a first side the encapsulated semiconductor device and electrically connected to the semiconductor device. The insulating layer is disposed on a second side of the encapsulated semiconductor device and comprises a groove pattern. The antenna is filled the groove pattern, wherein an upper surface of the antenna is substantially coplanar with an upper surface of the insulating layer.

Abstract: A semiconductor device is provided. The semiconductor device includes a source/drain region, a silicide layer on the source/drain region, an interlayer dielectric (ILD) layer over the silicide layer, and a source drain contact. The source/drain contact has a top portion extending through the ILD layer and a bottom portion embedded in the silicide layer.

Abstract: A method of forming a via to an underlying layer of a semiconductor device is provided. The method may include forming a pillar over the underlying layer using a sidewall image transfer process. A dielectric layer is formed over the pillar and the underlying layer; and a via mask patterned over the dielectric layer, the via mask having a mask opening at least partially overlapping the pillar. A via opening is etched in the dielectric layer using the via mask, the mask opening defining a first lateral dimension of the via opening in a first direction and the pillar defining a second lateral dimension of the via opening in a second direction different than the first direction. The via opening is filled with a conductor to form the via. A semiconductor device and via structure are also provided.

Abstract: Provided is an SOI substrate which has a substrate, an insulating layer formed over the substrate, and a semiconductor layer formed over the insulating layer. Optical waveguides are formed in the semiconductor layer of the SOI substrate. This substrate has a low resistance semiconductor layer and a high resistance semiconductor layer thereover. Further, wirings which are formed through insulating films are provided on the optical waveguides. In this manner, the low resistance semiconductor layer is arranged in the surface part of the substrate of the insulating films, thereby restraining an eddy current generated in the substrate due to an electric signal transmitted through the wirings.

Abstract: Structures and methods of making a dielectric region in a bulk silicon (Si) substrate of a mixed-signal integrated circuit (IC) provide a high-Q passive resonator. Deep trenches within the bulk Si substrate in <100> directions are expanded by wet etching to form contiguous cavities, which are filled by Si oxide to form a dielectric region. The dielectric region enhances the quality (Q) of an overlying passive resonator, formed in metallization layers of the mixed-signal IC.

Abstract: Disclosed herein is a structure conductive lines disposed in a base layer and separated by a first region. Pillars are each disposed over a respective one of the conductive lines. A dielectric fill layer is disposed over the pillars and extending between the pillars into the first region, and a void is disposed in the dielectric fill layer in the first region between the conductive lines.

Abstract: The present disclosure provides a method for forming an integrated circuit (IC) structure. The method includes providing a metal gate (MG), an etch stop layer (ESL) formed on the MG, and a dielectric layer formed on the ESL. The method further includes etching the ESL and the dielectric layer to form a trench. A surface of the MG exposed in the trench is oxidized to form a first oxide layer on the MG. The method further includes removing the first oxide layer using a H3PO4 solution.

Abstract: Embodiments of the present invention provide a method of forming contact structure for transistor. The method includes providing a semiconductor substrate having a first and a second gate structure of a first and a second transistor formed on top thereof, the first and second gate structures being embedded in a first inter-layer-dielectric (ILD) layer; epitaxially forming a first semiconductor region between the first and second gate structures inside the first ILD layer; epitaxially forming a second semiconductor region on top of the first semiconductor region, the second semiconductor region being inside a second ILD layer on top of the first ILD layer and having a width wider than a width of the first semiconductor region; and forming a silicide in a top portion of the second semiconductor region.

Abstract: Conventional approaches to integrating waveguides within standard electronic processes typically involve using a dielectric layer, such as polysilicon, single-crystalline silicon, or silicon nitride, within the in-foundry process or depositing and patterning a dielectric layer in the backend as a post-foundry process. In the present approach, the back-end of the silicon handle is etched away after in-foundry processing to expose voids or trenches defined using standard in-foundry processing (e.g., complementary metal-oxide-semiconductor (CMOS) processing). Depositing dielectric material into a void or trench yields an optical waveguide integrated within the front-end of the wafer. For example, a shallow trench isolation (STI) layer formed in-foundry may serve as a high-resolution patterning waveguide template in a damascene process within the front end of a die or wafer.

Abstract: A trench is etched in a semiconductor wafer by turning a first introduced gas introduced into a reaction chamber into plasma. A protection film is formed on a wall surface of the trench by turning a second introduced gas introduced into the reaction chamber into plasma. The protection film formed on a bottom surface of the trench is removed by turning a third introduced gas introduced into the reaction chamber into plasma. The reaction chamber is evacuated after the protection film formed on the bottom surface of the trench is removed.

Abstract: A nanogap of controlled width in-between noble metals is produced using sidewall techniques and chemical-mechanical-polishing. Electrical connections are provided to enable current measurements across the nanogap for analytical purposes. The nanogap in-between noble metals may also be formed inside a Damascene trench. The nanogap in-between noble metals may also be inserted into a crossed slit nanopore framework. A noble metal layer on the side of the nanogap may have sub-layers serving the purpose of multiple simultaneous electrical measurements.

Abstract: A method of forming a substrate opening includes forming a plurality of side-by-side openings in a substrate. At least some of immediately adjacent side-by-side openings are formed in the substrate to different depths relative one another. Walls that are laterally between the side-by-side openings are removed to form a larger opening having a non-vertical sidewall surface where the walls were removed in at least one straight-line vertical cross-section that passes through the sidewall surface orthogonally to the removed walls.

Abstract: Radiation detectors and methods of fabricating radiation detectors are provided. One method includes mechanically polishing at least a first surface of a semiconductor wafer using a polishing sequence including a plurality of polishing steps, wherein a last polishing step of the polishing sequence includes polishing with a slurry having a grain size smaller than about 0.1 ?m to create a polished first surface. The method also includes applying (i) an encapsulation layer on a top of the polished first surface to seal the polished first surface and (ii) a photoresist layer on top of the encapsulation layer on the polished first surface. The method further includes creating undercuts of the encapsulation layer under the photoresist layer. The method additionally includes partially etching the polished first surface of the semiconductor via the openings in the photoresist layer and in the encapsulation layer to partially etch the semiconductor creating etched regions.

Abstract: A multi-field effect transistor (FET) device includes a first FET device arranged on a substrate, the first FET device including a first active region and a second active region, a second FET device arranged on the substrate, the second FET device including a first active region and a second active region, and a first conductive interconnect electrically connecting the first active region of the first FET device to the first active region of the second FET device, the first conductive interconnect having a first cross sectional area proximate to the first active region of the first FET device that is greater than a second cross sectional area proximate to the first active region of the second FET device.

Abstract: A semiconductor device is provided, in which it becomes easy to reliably couple a plug conductive layer and a wiring layer located over the plug conductive layer to each other and falling of the wiring can be suppressed. The plug conductive layer contacts a source/drain region formed over a major surface of the semiconductor substrate. A contact conductive layer is formed so as to contact both the upper surface and the side surface of the plug conductive layer. Wiring layers are formed over the contact conductive layer so as to be electrically coupled to the contact conductive layer.

Abstract: Semiconductor devices and methods for forming a semiconductor device are presented. The method includes providing a substrate having a device component with a contact region. A contact dielectric layer is formed on the substrate, covering the substrate and device component. The contact dielectric layer includes a lower contact dielectric layer, an intermediate contact dielectric etch stop layer formed on the lower contact dielectric layer, and an upper contact dielectric layer formed on the intermediate contact dielectric etch stop layer. A contact opening is formed through the contact dielectric layer. The contact opening has an upper contact sidewall profile in the upper contact dielectric layer and a lower tapered contact sidewall profile in the lower contact dielectric layer. The tapered sidewall profile prevents shorting with the device component.

Abstract: The semiconductor device fabrication method of the present invention includes: laminating a plurality of amorphous silicon films on a semiconductor substrate, forming through-holes that pass through the plurality of amorphous silicon films, and subjecting the plurality of amorphous silicon films 301 that include the through-holes to an etching process that uses an alkaline aqueous solution; wherein the plurality of amorphous silicon films is formed to include a first amorphous silicon film and a second amorphous silicon film in which the rate of etching by using the alkaline aqueous solution is slower than that of the first amorphous silicon film and the first amorphous silicon film is interposed between the semiconductor substrate and the second amorphous silicon film.

Abstract: A hole formation method including applying a pillar-forming liquid to a base material, to thereby form a pillar; applying an insulating film-forming material to the base material on which the pillar has been formed, to thereby form an insulating film; removing the pillar to form an opening in the insulating film; and heat treating the insulating film in which the opening has been formed.

Abstract: A method for forming large substantially defect-free void areas on a semiconductor integrated circuit chip includes processing the chip through the passivation level processing operations then forming one or more openings in a designated blank area of the integrated circuit chip in a separate dedicated etching operation. The one or more openings may constitute 5-10% or more of the total area of the semiconductor chip. The void areas are deep trench openings that extend through the passivation layer and through all of the other material layers in the blank area exposing the substrate surface in one embodiment and through all material layers except for a field oxide layer formed directly on the substrate in another embodiment.

Abstract: Native oxides and associated residue are removed from surfaces of a substrate by sequentially performing two plasma cleaning processes on the substrate in a single processing chamber. The first plasma cleaning process removes native oxide formed on a substrate surface by generating a cleaning plasma from a mixture of ammonia (NH3) and nitrogen trifluoride (NF3) gases, condensing products of the cleaning plasma on the native oxide to form a thin film that contains ammonium hexafluorosilicate ((NH4)2SiF6), and subliming the thin film off of the substrate surface. The second plasma cleaning process removes remaining residues of the thin film by generating a second cleaning plasma from nitrogen trifluoride gas. Products of the second cleaning plasma react with a few angstroms of the bare silicon present on the surface, forming silicon tetrafluoride (SiF4) and lifting off residues of the thin film.

Abstract: A method includes the stage of partially removing a first insulator layer to form an opening passing through the first insulator layer by plasma etching using a gas of a first type, and the stage of partially removing a second insulator layer to form an opening passing through the second insulator layer by plasma etching using a gas of a second type. The gas of a first type contains a first component capable of etching the first insulator layer, and a gas of the second type contains a second component different from the first component, capable of etching the second insulator layer and a third component having a higher deposition ability than the second component.

Abstract: A chip package is disclosed. The package includes a semiconductor chip having a first surface and a second surface opposite thereto, at least one conductive pad adjacent to the first surface, and an opening extending toward the first surface from the second surface to expose the conductive pad. The caliber adjacent to the first surface is greater than that of the opening adjacent to the second surface. An insulating layer and a redistribution layer (RDL) are successively disposed on the second surface and extend to a sidewall and a bottom of the opening, in which the RDL is electrically connected to the conductive pad through the opening. A passivation layer covers the RDL and partially fills the opening to form a void between the passivation layer and the conductive pad in the opening. A fabrication method of the chip package is also disclosed.

Abstract: A method of producing plurality of etched features in an electronic device is disclosed that avoids micro-loading problems thus maintaining more uniform sidewall profiles and more uniform critical dimensions. The method comprises performing a first time-divisional plasma etch process step within a plasma chamber to a first depth of the plurality of etched features, and performing a flash process step to remove any polymers from exposed surfaces of the plurality of etched features without requiring an oxidation step. The flash process step is performed independently of the time-divisional plasma etch step. A second time-divisional plasma etch process step is performed within the plasma chamber to a second depth of the plurality of etched features. The method may be repeated until a desired etch depth is reached.

Abstract: A method of etching trenches into silicon of a semiconductor substrate includes forming a mask over silicon of a semiconductor substrate, with the mask comprising trenches formed there-through. Plasma etching is conducted to form trenches into the silicon of the semiconductor substrate using the mask. In one embodiment, the plasma etching includes forming an etching plasma using precursor gases which include SF6, an oxygen-containing compound, and a nitrogen-containing compound. In one embodiment, the plasma etching includes an etching plasma which includes a sulfur-containing component, an oxygen-containing component, and NFx.

Abstract: An integrated circuit structure includes a semiconductor substrate and a hard mask layer formed on the semiconductor substrate. The integrated circuit structure further includes at least a conductive layer formed in the hard mask layer and a via extending from the hard mask layer to at least a portion of the semiconductor substrate, wherein the via has a round corner and a tapered sidewall.

Abstract: A first dielectric layer is formed over a substrate. A second dielectric layer is formed over the first dielectric layer. A first opening is formed in the second dielectric layer. A second opening is formed in the first dielectric layer.

Abstract: A method for forming vias and trenches for an interconnect structure on a substrate includes exposing via pitch reduction patterns in a photoresist layer, developing the patterns to remove the via pitch reduction patterns, etching the photoresist layer partially using a polymer gas to reshape the pattern into small via shapes, and etching the remaining photoresist layer to extend the reshaped pattern. The reshaped small via shape patterns have a smaller pitch than the via pitch reduction patterns in a long direction. For via pitch reduction patterns having two vias each, the pattern has a peanut-shape. During the reshaping etch operation, the polymer gas deposits more in a pinched-in middle section while allowing downward etch in unpinched sections.

Abstract: A method for fabricating a semiconductor device includes forming a plurality of first hard mask patterns separated by a plurality of trenches on a target layer, forming a plurality of second hard mask patterns filling the plurality of trenches, forming a plurality of first opening units in the plurality of second hard mask patterns, forming a plurality of second opening units in the plurality of first hard mask patterns and forming a plurality of patterns using the plurality of first opening units and the plurality of second opening units, which are transferred by etching the target layer.

Abstract: A semiconductor substrate having dot marks is provided. Particularly, a semiconductor substrate having dot marks having an improved reading rate is provided. In a semiconductor substrate having a plurality of dot marks formed of recess portions having an inverted frustum shape, the plurality of dot marks constitutes a two-dimensional code disposed in a rectangular region of 0.25 mm2 to 9 mm2, the diameter W of the recess portion on the surface of the semiconductor substrate is 20 ?m to 200 ?m, is larger than the diameter w of the bottom surface of the recess portion, and is smaller than the thickness of the semiconductor substrate, the side surface of the recess portion has four or more trapezoidal flat taper surfaces, and the taper angle of the taper surface is in a range of 44° to 65° with respect to the surface of the semiconductor substrate.

Abstract: Embodiments of the present invention provide a contact structure for transistor. The contact structure includes a first epitaxial-grown region between a first and a second gate of, respectively, a first and a second transistor; a second epitaxial-grown region directly on top of the first epitaxial-grown region with the second epitaxial-grown region having a width that is wider than that of the first epitaxial-grown region; and a silicide region formed on a top portion of the second epitaxial-grown region with the silicide region having an interface, with rest of the second epitaxial-grown region, that is wider than that of the first epitaxial-grown region. In one embodiment, the second epitaxial-grown region is at a level above a top surface of the first and second gates of the first and second transistors.

Abstract: A compound semiconductor device includes a compound semiconductor laminated structure, a passivation film formed on the compound semiconductor laminated structure and having a through-hole, and a gate electrode formed on the passivation film so as to plug the through-hole. A grain boundary between different crystalline orientations is formed in the gate electrode, and a starting point of the grain boundary is located apart from the through-hole on a flat surface of the passivation film.

Abstract: A method of forming a dual gate oxide is disclosed which includes: providing a silicon substrate; depositing a first silicon oxide film over the silicon substrate; coating a photoresist over the first silicon oxide film; exposing and developing the photoresist to expose a portion of the first silicon oxide film; coating a crosslinking agent containing amine compound or polyamine compound on the photoresist and performing a heat curing process, thereby forming a protective layer of crosslinked macromolecules over the photoresist; removing the remaining crosslinking agent; performing a wet etching process to reduce a thickness of, or completely remove, the exposed portion of the first silicon oxide film; removing the photoresist and the protective layer formed thereon; and depositing a second silicon oxide film.

Abstract: Local and global reduction of critical dimension (CD) asymmetry in etch processing is described. In an example, a method of etching a wafer of to form a plurality of staircase structures with reduced local and global asymmetry involves forming a photoresist layer on a plurality of micron-scale semiconductor structures. The photoresist layer is then trimmed with a high pressure and pulsed plasma etch process performed in a reverse MESA mode.

Abstract: Approaches for multilayer pattern transfer for chemical guides are provided. In a typical embodiment, a device is formed by forming an etch mask layer (e.g., a nitride layer and an oxide layer) over a substrate (e.g., silicon (Si)). An orientation control layer (e.g., a neutral layer) is then formed over the etch mask layer, and an ARC layer (e.g., SiARC) is formed over the orientation control layer. In other embodiments, an organic planarization layer (OPL) and/or a protection layer may also be formed between the ARC layer and the orientation control layer. Regardless, a tapered etch profile/pattern may then be formed through the ARC and/or other layers.

Abstract: A trench is formed in a semiconductor substrate by depositing an etch mask on the substrate having an opening, etching of the trench through the opening, and doping the walls of the trench. The etching step includes a first phase having an etch power set to etch the substrate under the etch mask, and a second phase having an etch power set smaller than the power of the first phase. Further, the doping of the walls of the trench is applied through the opening of the etch mask.

Abstract: A gas cluster ion beam process is used to reduce and/or even eliminate metal void formation in an interconnect structure. In one embodiment, gas cluster ion beam etching forms a chamfer opening in an interconnect dielectric material. In another embodiment, gas cluster ion beam etching reduces the overhang profile of a diffusion barrier or a multilayered stack of a diffusion barrier and a plating seed layer that is formed within an opening located in an interconnect dielectric material. In yet another embodiment, a gas cluster ion beam process deactivates a surface of an interconnect dielectric material that is located at upper corners of an opening that is formed therein. In this embodiment, the gas cluster ion beam process deposits a material that deactivates the upper corners of each opening that is formed into an interconnect dielectric material.

Abstract: The width of a metal contact opening is formed to be smaller than the minimum feature size of a photolithographically-defined opening. The method forms the metal contact opening by first etching the fourth layer of a multilayered hard mask structure to have a number of trenches that expose the third layer of the multilayered hard mask structure. Following this, the third, second, and first layers of the multilayered hard mask structure are selectively etched to expose uncovered regions on the top surface of an isolation layer that touches and lies over a source region and a drain region. The uncovered regions on the top surface of the isolation layer are then etched to form the metal contact openings.

Abstract: A method for producing a deep trench in a substrate includes a series of elementary etch cycles each etching a portion of the trench. Each elementary cycle includes deposition of a passivation layer on the sidewalls and the bottom of the trench portion etched during previous cycles; followed by pulsed plasma anisotropic ion etching of the trench portion etched during previous cycles, the etching; being implemented in an atmosphere comprising a passivating species; and including a first etch sequence followed by a second etch sequence of less power than the power of the first etch sequence. The first etch sequence etches the passivation layer deposited in the bottom of the portion so as to access the substrate and etches the free substrate at the bottom of the portion while leaving a passivation layer on sidewalls of the portion.

Abstract: A method provides a PMR transducer. In one aspect, the method includes forming a trench in an intermediate layer using reactive ion etch(es). The trench top is wider than its bottom. In this aspect, the method also includes providing a seed layer using atomic layer deposition and providing a PMR pole on the seed layer. Portion(s) of the seed layer and PMR pole reside in the trench. In another aspect, the method includes providing a mask including a trench having a top wider than its bottom. In this aspect, the method includes providing mask material in the trench, providing an intermediate layer on the mask material and removing the mask material to provide another trench in the intermediate layer. In this aspect, the method also includes providing a PMR pole in the additional trench.

Abstract: An anisotropic silicon nitride etch provides selectivity to silicon and silicon oxide by forming a fluorohydrocarbon-containing polymer on silicon surfaces and silicon oxide surfaces. Selective fluorohydrocarbon deposition is employed to provide selectivity to non-nitride surfaces. The fluorohydrocarbon-containing polymer interacts with silicon nitride to form a volatile compound, thereby enabling etching of silicon nitride. The fluorohydrocarbon-containing polymer interacts with silicon oxide at a low reaction rate, retarding, or completely stopping, the etching of silicon oxide. The fluorohydrocarbon-containing polymer does not interact with silicon, and protects silicon from the plasma. The anisotropic silicon nitride etch can be employed to etch silicon nitride selective to silicon and silicon oxide in any dimension, including small dimensions less than 50 nm.

Abstract: A process for fabricating a tapered field plate dielectric for high-voltage semiconductor devices is disclosed. The process may include depositing a thin layer of oxide, depositing a polysilicon hard mask, depositing a resist layer and etching a trench area, performing deep silicon trench etch, and stripping the resist layer. The process may further include repeated steps of depositing a layer of oxide and anisotropic etching of the oxide to form a tapered wall within the trench. The process may further include depositing poly and performing further processing to form the semiconductor device.

Abstract: A method of etching a substrate comprises forming on the substrate, a plurality of double patterning features composed of silicon oxide, silicon nitride, or silicon oxynitride. The substrate having the double patterning features is provided to a process zone. An etching gas comprising nitrogen tri-fluoride, ammonia and hydrogen is energized in a remote chamber. The energized etching gas is introduced into the process zone to etch the double patterning features to form a solid residue on the substrate. The solid residue is sublimated by heating the substrate to a temperature of at least about 100° C.

Abstract: A semiconductor device according to one embodiment includes: a semiconductor substrate provided with a semiconductor element; a connecting member formed above the semiconductor substrate configured to electrically connect upper and lower conductive members; a first insulating film formed in the same layer as the connecting member; a wiring formed on the connecting member, the wiring including a first region and a second region, the first region contacting with a portion of an upper surface of the connecting member, and the second region located on the first region and having a width greater than that of the first region; and a second insulating film formed on the first insulating film so as to contact with at least a portion of the first region of the wiring and with a bottom surface of the second region.

Abstract: A mechanism for forming a semiconductor device is described. The semiconductor device includes a substrate and an inter-layer dielectric (ILD) layer over the substrate. The intermediate semiconductor device further includes a first layer set over the ILD layer and a second layer set over the first layer set. The intermediate semiconductor device further includes a photoresist layer over the second layer set. The method further includes etching the second layer set to form a tapered opening in the second layer set, the tapered opening having sidewalls at an angle with respect to a top surface of the ILD layer ranging from about 85-degrees to about 90-degrees, but less than 90-degrees. The method further includes etching the first layer set to form an opening in the first layer set and etching the ILD layer using the first layer set as a mask to form an opening in the ILD layer.

Abstract: This description relates to a method of making a semiconductor device including forming an inter-level dielectric (ILD) layer over a substrate and forming a layer set over the ILD layer. The method further includes etching the layer set to form a tapered opening in the layer set and etching the ILD layer using the layer set as a mask to form an opening in the ILD layer. The opening in the ILD layer has a line width roughness (LWR) of less than 3 nanometers (nm). This description also relates to a semiconductor device including an inter-level dielectric (ILD) layer over a substrate; and a layer set over the ILD layer. The layer set has a tapered opening within the layer set. Etching the layer set comprises forming the tapered opening having sidewalls at an angle with respect to a top surface of the ILD layer ranging from 85-degrees to 90-degrees.

Abstract: A method of fabricating a semiconductor device including providing a substrate having a front surface and a back surface. A masking element is formed on the front surface of the substrate. The masking element includes a first layer having a first opening and a second layer having a second opening of a greater width than the first opening. The second opening is a tapered opening. The method further includes etching a tapered profile via extending from the front surface to the back surface of the substrate using the formed masking element.

Abstract: A III-nitride trench device has a vertical conduction region with an interrupted conduction channel when the device is not on, providing an enhancement mode device. The trench structure may be used in a vertical conduction or horizontal conduction device. A gate dielectric provides improved performance for the device by being capable of withstanding higher electric field or manipulating the charge in the conduction channel. A passivation of the III-nitride material decouples the dielectric from the device to permit lower dielectric constant materials to be used in high power applications.

Abstract: In accordance with an embodiment of the present invention, a method of forming a semiconductor device includes forming a first cavity within a substrate. The first cavity is disposed under a portion of the substrate. The method further includes forming a first pillar within the first cavity to support the portion of the substrate.

Abstract: A method for forming a semiconductor device and a device made using the method are provided. In one example, the method includes forming a hard mask layer on a semiconductor substrate and patterning the hard mask layer to form multiple openings. The substrate is etched through the openings to form forming a plurality of trenches separating multiple semiconductor mesas. The trenches are partially filled with a dielectric material. The hard mask layer is removed and multiple-gate features are formed, with each multiple-gate feature being in contact with a top surface and sidewalls of at least one of the semiconductor mesas.