Abstract: A semiconductor device is formed on a semiconductor layer. A gate dielectric layer is formed over the semiconductor layer. A layer of gate material is formed over the gate dielectric layer. The layer of gate material is patterned to form a gate structure. Using the gate structure as a mask, an implant into the semiconductor layer is performed. To form a first patterned gate structure and a trench in the semiconductor layer surrounding a first portion and a second portion of the semiconductor layer and the gate, an etch through the gate structure and the semiconductor layer is performed. The trench is filled with insulating material.

Abstract: A process for manufacturing a suspended structure of semiconductor material envisages the steps of: providing a monolithic body of semiconductor material having a front face; forming a buried cavity within the monolithic body, extending at a distance from the front face and delimiting, with the front face, a surface region of the monolithic body, said surface region having a first thickness; carrying out a thickening thermal treatment such as to cause a migration of semiconductor material of the monolithic body towards the surface region and thus form a suspended structure above the buried cavity, the suspended structure having a second thickness greater than the first thickness. The thickening thermal treatment is an annealing treatment.

Abstract: A method for fabrication of a monolithically integrated SOI substrate capacitor has the steps of: forming an insulating trench, which reaches down to the insulator and surrounds a region of the monocrystalline silicon of a SOI structure, doping the monocrystalline silicon region, forming an insulating, which can be nitride, layer region on a portion of the monocrystalline silicon region, forming a doped silicon layer region on the insulating layer region, and forming an insulating outside sidewall spacer on the monocrystalline silicon region, where the outside sidewall spacer surrounds the doped silicon layer region to provide an isolation between the doped silicon layer region and exposed portions of the monocrystalline silicon region. The monocrystalline silicon region, the insulating layer region, and the doped silicon layer region constitute a lower electrode, a dielectric, and an upper electrode of the capacitor.

Abstract: A method is provided of forming a conductive via for contacting a bulk semiconductor region of a semiconductor-on-insulator (“SOI”) substrate. A first opening is formed in a conformal layer overlying a trench isolation region, where the trench isolation region shares an edge with the SOI layer. A dielectric layer then is deposited atop the conformal layer and the trench isolation region, after which a second opening is formed which is aligned with the first opening, the second opening extending through the dielectric layer to expose the bulk semiconductor region. Finally, the conductive via is formed in the second opening.

Abstract: A structure and method to produce an airgap on a substrate having a dielectric layer with a pattern transferred onto the dielectric layer and a self aligned block out mask transferred on the dielectric layer around the pattern.

Abstract: An integrated circuit has a buried insulation layer formed over a semiconductor substrate, and a semiconductor mesa formed over the buried insulation layer. A low resistivity guard ring substantially surrounds the semiconductor mesa and is in contact with the semiconductor substrate. The low resistivity guard ring is grounded and isolates the semiconductor mesa from RF signals.

Abstract: A method for manufacturing a semiconductor device that controls the influence of a thickness of a stopper film even if there is a change in the thickness of the stopper film by measuring the thickness prior to etching to a predetermined thickness.

Abstract: A method of forming an integrated circuit structure includes providing a semiconductor substrate; forming a first isolation region in the semiconductor substrate; after the step of forming the first isolation region, forming a metal-oxide-semiconductor (MOS) device at a surface of the semiconductor substrate, wherein the step of forming the MOS device comprises forming a source/drain region; and after the step of forming the MOS device, forming a second isolation region in the semiconductor substrate.

Abstract: Example embodiments relate to a semiconductor device and a method of manufacturing the same. A semiconductor device according to example embodiments may have reduced disturbances during reading operations and a reduced short channel effect. The semiconductor device may include a semiconductor substrate having a body and a pair of fins protruding from the body. Inner spacer insulating layers may be formed on an upper portion of an inner sidewall of the pair of fins so as to reduce the entrance to the region between the pair of fins. A gate electrode may cover a portion of the external sidewalls of the pair of fins and may extend across the inner spacer insulating layers so as to define a void between the pair of fins. Gate insulating layers may be interposed between the gate electrode and the pair of fins.

Abstract: A device made of single-crystal silicon having a first side, a second side which is situated opposite to the first side, and a third side which extends from the first side to the second side, the first side and the second side each extending in a 100 plane of the single-crystal silicon, the third side extending in a first area in a 111 plane of the single-crystal silicon. The third side extends in a second area in a 110 plane of the single-crystal silicon. Furthermore, a production method for producing a device made of single-crystal silicon is described.

Abstract: To easily and accurately flush a substrate surface serving an SOI area with a substrate surface serving as a bulk area, make a buried oxide film, and prevent an oxide film from being exposed on substrate surface. After partially forming a mask oxide film 23 on the surface of a substrate 12 constituted of single crystal silicon, oxygen ions 16 are implanted into the surface of the substrate through the mask oxide film, and the substrate is annealed to form an buried oxide film 13 inside the substrate. Further included is a step of forming a predetermined-depth concave portion 12c deeper than substrate surface 12b serving as a bulk area on which the mask oxide film is formed on the substrate surface 12a serving as an SOI area by forming a thermally grown oxide film 21 on the substrate surface 12a serving as an SOI area on which the mask oxide film is not formed between the step of forming the mask oxide film and the step of implanting oxygen ions.

Abstract: A dielectric liner is formed in first and second trenches respectively in first and second portions of a substrate. A layer of material is formed overlying the dielectric liner so as to substantially concurrently substantially fill the first trench and partially fill the second trench. The layer of material is removed substantially concurrently from the first and second trenches to expose substantially all of the dielectric liner within the second trench and to form a plug of the material in the one or more first trenches. A second layer of dielectric material is formed substantially concurrently on the plug in the first trench and on the exposed portion of the dielectric liner in the second trench. The second layer of dielectric material substantially fills a portion of the first trench above the plug and the second trench.

Abstract: A single crystal semiconductor separated from a single crystal semiconductor substrate is formed partly over a supporting substrate with a buffer layer provided therebetween. The single crystal semiconductor is separated from the single crystal semiconductor substrate by irradiation with accelerated ions, formation of a fragile layer by the ion irradiation, and heat treatment. A non-single crystal semiconductor layer is formed over the single crystal semiconductor and irradiated with a laser beam to be crystallized, whereby an SOI substrate is manufactured.

Abstract: A method for producing a component having a semiconductor substrate, in which porous semiconductor material is generated for the purpose of developing at least one thermally decoupled pattern. In the material that has been rendered porous, a recess or a plurality of recesses is/are etched to produce at least one region that is defined by the one recess or the plurality of recesses and is thermally decoupled. On the at least one region, the pattern to be thermally decoupled is then formed.

Abstract: Methods for fabricating a device structure in a semiconductor-on-insulator substrate. The method includes forming a first isolation region in the substrate device layer that extends from a top surface of the device layer to a first depth and forming a second isolation region in the semiconductor layer that extends from the top surface of the semiconductor layer to a second depth greater than the first depth. The method further includes forming a doped region of the device structure in the semiconductor layer that is located vertically between the first isolation region and the insulating layer.

Abstract: The invention relates to a method for producing a semiconducting structure including: controlled formation, through a mask (31), in a first substrate (30) in a semiconducting material, of at least one first area in an insulating material (36), up to the level of the lower surface (35) of the mask, before or during the removal of the mask.

Abstract: A semiconductor fabrication method. The method includes providing a semiconductor substrate, wherein the semiconductor substrate includes a semiconductor material. Next, a top portion of the semiconductor substrate is removed. Next, a first semiconductor layer is epitaxially grown on the semiconductor substrate, wherein a first atomic percent of a first semiconductor material in the first semiconductor layer is equal to a substrate atomic percent of the substrate semiconductor material in the semiconductor substrate.

Abstract: In one embodiment of the present invention, a method for manufacturing a semiconductor device includes: forming a to-be-removed layer on a semiconductor substrate; forming a semiconductor layer on the to-be-removed layer; forming a trench that passes through the semiconductor layer to the to-be-removed layer in an SOI region; removing the to-be-removed layer by using the trench and creating a cavity; and forming an insulating film in the cavity.

Abstract: A SOI device features a conductive pathway between active SOI devices and a bulk SOI substrate. The conductive pathway provides the ability to sink plasma-induced process charges into a bulk substrate in the event of process charging, such as interlayer dielectric deposition in a plasma environment, plasma etch deposition, or other fabrication provides. A method is also disclosed which includes dissipating electrostatic and process charges from a top of a SOI device to the bottom of the device. The top and bottom of the SOI device may characterize a region of active devices and a semiconductor method respectively. The method further includes a single masking step to create seed regions for an epitaxial-silicon pathway.

Abstract: A method of fabricating a high-performance planar back-gate CMOS structure having superior short-channel characteristics and reduced capacitance using processing steps that are not too lengthy or costly is provided. Also provided is a high-performance planar back-gate CMOS structure that is formed utilizing the method of the present invention. The method includes forming an opening in an upper surface of a substrate. Thereafter, a dopant region is formed in the substrate through the opening. In accordance with the inventive method, the dopant region defines a back-gate conductor of the inventive structure. Next, a front gate conductor having at least a portion thereof is formed within the opening.

Abstract: A bonded wafer is produced by a method comprising a step of implanting ions of a light element such as hydrogen, helium or the like into a wafer for active layer at a predetermined depth position to form an ion implanted layer, a step of bonding the wafer for active layer to a wafer for support substrate through an insulating film, a step of exfoliating the wafer at the ion implanted layer, a first heat treatment step of conducting a sacrificial oxidation for reducing damage on a surface of an active layer exposed through the exfoliation and a second heat treatment step of raising a bonding strength, in which the second heat treatment step is continuously conducted after the first heat treatment step without removing an oxide film formed on the surface of the active layer.

Abstract: A process for producing an adhered SOI substrate without causing cracking and peeling of a single-crystal silicon thin film. The process consists of selectively forming a porous silicon layer in a single-crystal semiconductor substrate, adding hydrogen into the single-crystal semiconductor substrate to form a hydrogen-added layer, adhering the single-crystal semiconductor substrate to a supporting substrate, separating the single-crystal semiconductor substrate at the hydrogen-added layer by thermal annealing, performing thermal annealing again to stabilize the adhering interface, and selectively removing the porous silicon layer to give single-crystal silicon layer divided into islands.

Abstract: A method for forming a passivation layer is disclosed. In the method, a substrate containing a top surface and a bottom surface opposite to the top surface is first provided, wherein a plurality of conductive pads are disposed on the top surface thereof. Thereafter, a first passivation layer is formed on the top surface of the substrate, wherein the first passivation layer has a characteristic of photoresist. A first exposure/develop step is then performed to form a plurality of first openings in the first passivation layer, wherein the conductive pads are exposed through the first openings. Then, a second passivation layer is formed on the first passivation layer, wherein the second passivation layer has a characteristic of photoresist. A second exposure/develop step is then performed to form a plurality of second openings in the second passivation layer, wherein the conductive pads are exposed through the second openings.

Abstract: A semiconductor structure fabrication method. The method includes providing a semiconductor structure which includes a first semiconductor layer and a dielectric bottom portion in the first semiconductor layer. A second semiconductor layer on the first semiconductor layer is formed. The first and second semiconductor layers include a semiconductor material. A dielectric top portion and a first STI (Shallow Trench Isolation) region are formed in the second semiconductor layer. The dielectric top portion is in direct physical contact with the dielectric bottom portion.

Abstract: A method is provided of forming a conductive via in contact with a bulk semiconductor region of a semiconductor-on-insulator (“SOI”) substrate. A first opening is formed in a conformal layer overlying a trench isolation region. The trench isolation region may share an edge with an SOI layer of the substrate. Desirably, a dielectric layer is deposited over a top surface of the conformal layer and the trench isolation region. A second opening can then be formed which extends through the dielectric layer and the first opening in the conformal layer. Desirably, portions of the bulk semiconductor region and the top surface of the conformal layer are exposed within the second opening. The second opening can then be filled with at least one of a metal or a semiconductor to form a conductive element contacting the exposed portions of the bulk semiconductor region and the top surface of the conformal layer.

Abstract: An integrated semiconductor structure containing at least one device formed upon a first crystallographic surface that is optimal for that device, while another device is formed upon a second different crystallographic surface that is optimal for the other device is provided. The method of forming the integrated structure includes providing a bonded substrate including at least a first semiconductor layer of a first crystallographic orientation and a second semiconductor layer of a second different crystallographic orientation. A portion of the bonded substrate is protected to define a first device area, while another portion of the bonded substrate is unprotected. The unprotected portion of the bonded substrate is then etched to expose a surface of the second semiconductor layer and a semiconductor material is regrown on the exposed surface. Following planarization, a first semiconductor device is formed in the first device region and a second semiconductor device is formed on the regrown material.

Abstract: The present invention provides a method for manufacturing a semiconductor device, comprising the steps of preparing a substrate having a quartz support substrate and a silicon layer, forming a base or substrate silicon oxide film over the entire upper surface of the silicon layer, forming a silicon nitride film over the entire upper surface of the substrate silicon oxide film by a plasma CVD method, patterning the silicon nitride film thereby to form a mask pattern having a circumferential exposure portion that exposes the substrate silicon oxide film in a circumferential area, a first opening pattern that exposes the substrate silicon oxide film in an element isolation area, and a second opening pattern that exposes the substrate silicon oxide film within a peripheral area, and thermally oxidizing the substrate using the mask pattern as a mask thereby to form an element isolation structure portion in the element isolation area.

Abstract: The invention relates to a method includes etching at least one shallow trench in at least an SIO layer; forming a dielectric liner at an interface of the SIO layer and the SIO layer; forming a metal or metal alloy layer in the shallow trench on the dielectric liner; and filling the shallow trench with oxide material over the metal or metal alloy.

Abstract: A method of fabricating a semiconductor device includes forming an ion implanted region on a semiconductor substrate in a cell/core region. The semiconductor substrate is selectively etched to form a recess. The recess exposes a boundary of the ion implanted region. The ion implanted region exposed at the bottom of the recess is removed to form an under-cut space in the semiconductor substrate. An insulating film is formed to form a substrate having a silicon-on-insulator (SOI) structure in the cell/core region. The insulating film fills the under-cut space and the recess.

Abstract: Provided is a strained SOI structure and a method of manufacturing the strained SOI structure. The strained SOI structure includes an insulating substrate, a SiO2 layer formed on the insulating substrate, and a strained silicon layer formed on the SiO2 layer.

Abstract: A method for imparting stress to the channel region of a transistor is provided. In accordance with the method, a semiconductor layer (307) is provided which has a dielectric layer (305) disposed beneath it. A trench (319) is created which extends through the semiconductor layer and into the dielectric layer, and the trench is backfilled with a stressor material (320), thereby forming a trench isolation structure. A channel region (326) is defined in the semiconductor layer adjacent to the trench isolation structure.

Abstract: In a method of fabricating a flash memory device, a semiconductor substrate includes a tunnel insulating layer and a charge storage layer formed in an active region and a trench formed in an isolation region. A first insulating layer is formed to fill a part of the trench. A second insulating layer is formed on the first insulating layer so that the trench is filled. The first and second insulating layers are removed such that the first and second insulating layers remain on sidewalls of the charge storage layer and on a part of the trench. A third insulating layer is formed on the first and second insulating layers so that a space defined by the charge storage layer is filled. The third insulating layer is removed so that a height of the third insulating layer is lowered.

Abstract: A structure and method of fabrication of a semiconductor device having a stress relief layer under a stress layer in one region of a substrate. In a first example, a stress relief layer is formed over a first region of the substrate (e.g., PFET region) and not over a second region (e.g., NFET region). A stress layer is over the stress relief layer in the first region and over the devices and substrate/silicide in the second region. The NFET transistor performance is enhanced due to the overall tensile stress in the NFET channel while the degradation in the PFET transistor performance is reduced/eliminated due to the inclusion of the stress relief layer. In a second example embodiment, the stress relief layer is formed over the second region, but not the first region and the stress of the stress layer is reversed.

Abstract: A compressive stress is applied to a channel region of a PFET by structure including a discrete dielectric stressor element that fully underlies the bottom surface of an active semiconductor region in which the source, drain and channel region of the PFET is disposed. In particular, the dielectric stressor element includes a region of collapsed oxide which fully contacts the bottom surface of the active semiconductor region such that it has an area coextensive with an area of the bottom surface. Bird's beak oxide regions at edges of the dielectric stressor element apply an upward force at edges of the dielectric stressor element to impart a compressive stress to the channel region of the PFET.

Abstract: A silicon-on-insulator wafer (10). The SOI wafer (10) comprises a top silicon layer (6), a silicon substrate (4), and an oxide insulator layer (2) disposed across the wafer (10) and between the silicon substrate (4) and the top silicon layer (6). The oxide insulator layer (2) has at least one of a contoured top surface (8a, 8b, 8c, 8d, 8e) and a contoured bottom surface (12e). Also provided are processes for manufacturing such a SOI wafer (10).

Abstract: A method of forming a dielectric layer is provided. A first dielectric layer is formed on a substrate having metal layers formed thereon. The first dielectric layer includes overhangs in the spaces between two neighboring metal layers and voids under the overhangs. The first dielectric layer is partially removed to cut off the overhangs and expose the voids and therefore openings are formed. A second dielectric layer is formed on the dielectric layer to fill up the opening.

Abstract: A plurality of metal interconnects incorporating dielectric spacers and a method to form such dielectric spacers are described. In one embodiment, the dielectric spacers adjacent to neighboring metal interconnects are discontiguous from one another. In another embodiment, the dielectric spacers may provide a region upon which un-landed vias may effectively land.

Abstract: A method of forming a semiconductor structure (and the resulting structure), includes straining a free-standing semiconductor, and fixing the strained, free-standing semiconductor to a substrate.

Abstract: Methods of forming air gaps between interconnects of integrated circuits and structures thereof are disclosed. A first insulating material is deposited over a workpiece, and a second insulating material having a sacrificial portion is deposited over the first insulating material. Conductive lines are formed in the first and second insulating layers. The second insulating material is treated to remove the sacrificial portion, and at least a portion of the first insulating material is removed, forming air gaps between the conductive lines. The second insulating material is impermeable as deposited and permeable after treating it to remove the sacrificial portion. A first region of the workpiece may be masked during the treatment, so that the second insulating material becomes permeable in a second region of the workpiece yet remains impermeable in the first region, thus allowing the formation of the air gaps in the second region, but not the first region.

Abstract: In one embodiment, a semiconductor device has an active region defined by an isolation layer formed inside an STI trench that includes an upper trench and a lower trench having a substantially curved cross-sectional profile under the upper trench so that the lower trench is in communication with the upper trench. Since the upper trench has a sidewall tapered with a positive slope, a good gap filling property can be obtained when filling the upper trench with an insulating layer. By forming a void in the lower trench, a dielectric constant at the bottom of the isolation layer is lower than a dielectric constant at an oxide layer, thereby improving the isolation property. The isolation layer includes a first insulating layer formed inside only the upper trench and covering an inner wall of the upper trench in the form of a spacer.

Abstract: A semiconductor amplifier is provided comprising, a substrate and one or more unit amplifying cells (UACs) formed on the substrate, wherein each UAC is laterally surrounded by a first lateral dielectric filled trench (DFT) isolation wall extending at least to the substrate and multiple UACs are surrounded by a second lateral DFT isolation wall of similar depth outside the first isolation walls, and further semiconductor regions lying between the first isolation walls when two or more unit cells are present, and/or lying between the first and second isolation walls, are electrically floating with respect to the substrate. This reduces the parasitic capacitance of the amplifying cells and improves the power added efficiency. Excessive leakage between buried layer contacts when using high resistivity substrates is avoided by providing a further semiconductor layer of intermediate doping between the substrate and the buried layer contacts.

Abstract: A semiconductor structure for a dynamic random access memory (DRAM) cell array that includes a plurality of vertical memory cells built on a semiconductor-on-insulator (SOI) wafer and a body contact in the buried dielectric layer of the SOI wafer. The body contact electrically couples a semiconductor body with a channel region of the access device of one vertical memory cell and a semiconductor substrate of the SOI wafer. The body contact provides a current leakage path that reduces the impact of floating body effects upon the vertical memory cell. The body contact may be formed by an ion implantation process that modifies the stoichiometry of a region of the buried dielectric layer so that the modified region becomes electrically conductive with a relatively high resistance.

Abstract: The present invention relates to a method of manufacturing a semiconductor substrate, which enables a semiconductor device to have high speed operating characteristics and high performance characteristics such as lower electrical power consumption, and a method of manufacturing a semiconductor device including a method of manufacturing the semiconductor substrate thereof in a process, as well as to a semiconductor substrate manufactured by the method of manufacturing the same and a semiconductor device manufactured using the semiconductor substrate.

Abstract: A method of manufacturing a semiconductor device that includes the steps of forming an oxide film on a surface layer section, forming a window section by selectively removing the oxide film, forming a first semiconductor layer, forming a second semiconductor layer, forming a pair of support member holes for exposing the substrate semiconductor layer, forming a support member on the active surface side of the semiconductor substrate, forming an end-exposed surface exposing at least a part of an end of the first semiconductor layer, forming a substrate semiconductor layer exposed surface, removing the first semiconductor layer below the support member by wet etching, filling a hollow section obtained by the wet etching with an oxide film using thermal oxidation, exposing the second semiconductor layer and providing a semiconductor device to the second semiconductor layer.

Abstract: Example embodiments relate to a semiconductor device and a method of manufacturing the same. A semiconductor device according to example embodiments may have reduced disturbances during reading operations and a reduced short channel effect. The semiconductor device may include a semiconductor substrate having a body and a pair of fins protruding from the body. Inner spacer insulating layers may be formed on an upper portion of an inner sidewall of the pair of fins so as to reduce the entrance to the region between the pair of fins. A gate electrode may cover a portion of the external sidewalls of the pair of fins and may extend across the inner spacer insulating layers so as to define a void between the pair of fins. Gate insulating layers may be interposed between the gate electrode and the pair of fins.

Abstract: A semiconductor device and related method of manufacture are disclosed. The device comprises; a trench having a corner portion formed in the semiconductor substrate, a first oxide film formed on an inner wall of the trench and having an upper end portion exposing the corner portion of the semiconductor substrate, a nitride liner formed on the first oxide film, a second oxide film formed in contact with the upper end of the first oxide film and on the exposed corner portion and an upper surface of the semiconductor substrate, a field insulating film formed on the nitride liner to substantially fill the trench, and a field protecting film formed in contact with the second oxide film and filling a trench edge recess formed between the field insulating film and the second oxide film.

Abstract: The present invention provides a method for forming low-defect density changed-orientation Si by amorphization/templated recrystallization (ATR) processes in which regions of Si having a first crystal orientation are amorphized by ion implantation and then recrystallized into the orientation of a template layer having a different orientation. More generally, the invention relates to the high temperature annealing conditions needed to eliminate the defects remaining in Si-containing single crystal semiconductor materials formed by ion-implant-induced amorphization and templated recrystallization from a layer whose orientation may be the same or different from the amorphous layer's original orientation. The key component of the inventive method is a thermal treatment for minutes to hours in the temperature range 1250-1330° C. to remove the defects remaining after the initial recrystallization anneal.

Abstract: Structures and a method are disclosed for grounding gate-stack and/or silicon active region front-end-of-line structures on a silicon-on-insulator (SOI) substrate, which may be used as test structures for VC inspection. In one embodiment, a structure includes a grounded bulk silicon substrate having the SOI substrate thereover, the SOI substrate including a silicon-on-insulator (SOI) layer and a buried oxide (BOX) layer; the silicon active region having at least one finger element within the SOI layer, the at least one finger element isolated by a shallow trench isolation (STI) layer; and a polysilicon ground intersecting the at least one finger element and extending through the STI layer and the BOX layer to the grounded bulk silicon substrate, the polysilicon ground contacting the silicon active region and the grounded bulk silicon substrate.

Abstract: To easily and accurately flush a substrate surface serving an SOI area with a substrate surface serving as a bulk area, make a buried oxide film, and prevent an oxide film from being exposed on substrate surface. After partially forming a mask oxide film 23 on the surface of a substrate 12 constituted of single crystal silicon, oxygen ions 16 are implanted into the surface of the substrate through the mask oxide film, and the substrate is annealed to form a buried oxide film 13 inside the substrate. Further included is a step of forming a predetermined-depth concave portion 12c deeper than substrate surface 12b serving as a bulk area on which the mask oxide film is formed on the substrate surface 12a serving as an SOI area by forming a thermally grown oxide film 21 on the substrate surface 12a serving as an SOI area on which the mask oxide film is not formed between the step of forming the mask oxide film and the step of implanting oxygen ions.

Abstract: A semiconductor device, comprises: a transistor having structured to include a gate electrode formed on a semiconductor layer on a semiconductor substrate via a gate insulating film, and a source layer and a drain layer formed on the semiconductor layer sandwiching the gate electrode; a hollow portion existing between the source layer and the semiconductor substrate, and between the drain layer and the semiconductor substrate, respectively; and the hollow portion in absence between the semiconductor layer under the gate electrode and the semiconductor substrate.