33results about How to "Enhanced transistor performance" patented technology

A vertical device geometry for a carbon-nanotube-based field effect transistor has one or multiple carbon nanotubes formed in a trench.

Methods for forming asymmetric gate structures comprising spacer elements disposed on the opposed sides of a gate electrode and having a different width are disclosed. The asymmetric gate structures are employed to form an asymmetric design of a halo region and extension regions of a field effect transistor using a symmetric implantation scheme, or to further enhance the effectiveness of asymmetric implantation schemes. The transistor performance may be significantly enhanced for a given basic transistor architecture. In particular, a large overlap area may be created at the source side with a steep concentration gradient of the PN junction due to the provision of the halo region, whereas the drain overlap may be significantly reduced or may even be completely avoided to further enhance the transistor performance.

By removing a portion of a halo region or by avoiding the formation of the halo region within the extension region, which may be subsequently formed on the basis of a re-grown semiconductor material, the threshold roll off behavior may be significantly improved, wherein an enhanced current drive capability may simultaneously be achieved.

A layered structure comprises a variable wettability layer including a material that changes a critical surface tension in response to energy provided thereto, the wettability changing layer including at least a high surface energy part of large critical surface tension and a low surface energy part of low critical surface tension, a conductive layer formed on the variable wettability layer at the high surface energy tension part, and a semiconductor layer formed on the variable wettability layer at the low surface energy part.

The present invention teaches the formation of CMOS transistors using interfacial nitrogen at the interface between the lightly doped extension regions and an overlying insulating layer in combination with a capping layer of silicon nitride, both prior to the final source/drain anneal. Doses and energies may be increased for the P-channel lightly-doped drain, source and drain regions. The resulting transistors exhibit desirably high drive current and low off-state leakage current and overlap capacitance.

Integrated circuits are provided that have volatile memory elements. The memory elements produce output signals. The integrated circuits may be programmable logic device integrated circuits containing programmable core logic including transistors with gates. The core logic is powered using a core logic power supply level defined by a core logic positive power supply voltage and a core logic ground voltage. When loaded with configuration data, the memory elements produce output signals that are applied to the gates of the transistors in the core logic to customize the programmable logic device. The memory elements are powered with a memory element power supply level defined by a memory element positive power supply voltage and a memory element ground power supply voltage. The memory element power supply level is elevated with respect to the core logic power supply level.

A transistor and method of manufacture thereof. A semiconductor workpiece is doped before depositing a gate dielectric material. Using a separate anneal process or during subsequent anneal processes used to manufacture the transistor, dopant species from the doped region of the workpiece are outdiffused into the gate dielectric, creating a doped gate dielectric. The dopant species fill vacancies in the atomic structure of the gate dielectric, resulting in a transistor having increased speed, reduced power consumption, and improved voltage stability.

A method for forming shallow trench isolation in a semiconductor device. The method includes forming a pad oxide and a pad nitride on a semiconductor substrate in successive order, forming a trench in the substrate by etching the pad nitride, the pad oxide and the substrate, removing a portion of the pad oxide to expose top corners of the trench, and rounding the exposed portion of the top corners of the trench by a wet chemical etch.

During the manufacturing process for forming sophisticated transistor elements, the gate height may be reduced and a recessed drain and source configuration may be obtained in a common etch sequence prior to forming respective metal silicide regions. Since the corresponding sidewall spacer structure may be maintained during the etch sequence, controllability and uniformity of the silicidation process in the gate electrode may be enhanced, thereby obtaining a reduced degree of threshold variability. Furthermore, the recessed drain and source configuration may provide reduced overall series resistance and enhanced stress transfer efficiency.

The preferred embodiment of the present invention provides a transistor structure and method for fabricating the same that overcomes the disadvantages of the prior art. In particular, the preferred structure and method results in lower leakage and junction capacitance by using raised source and drains which are partially isolated from the substrate by a dielectric layer. The raised source and drains are preferably fabricated from the same material layer used to form the transistor gate. The preferred method for fabricating the transistor uses hybrid resist to accurately pattern the gate material layer into regions for the gate, the source and the drain. The source and drain regions are then connected to the substrate by growing silicon. The preferred method thus results in an improved transistor structure while not requiring excessive fabrication steps.

By modifying the dielectric liner for a spacer structure so as to exhibit an enhanced diffusion blocking characteristic, for instance by incorporating nitrogen, the out-diffusion of P-dopants, such as boron, into the dielectric material may be significantly reduced. Consequently, transistor performance, especially of P-type transistors, may be significantly enhanced while nevertheless a high degree of compatibility with conventional techniques may be maintained.

When forming sophisticated transistors, the channel region may be provided such that the gradient of the band gap energy of the channel material may result in superior charge carrier velocity. For example, a gradient in concentration of germanium, carbon and the like may be implemented along the channel length direction, thereby obtaining higher transistor performance.

A thin-film field-effect transistor is formed by forming a dielectric layer adjacent a gate, forming a source region and a drain region, and forming a semiconductor layer on the dielectric layer. The semiconductor layer is deposited by spray pyrolysis and comprises a material selected from a group comprising: oxides; oxide-based materials; mixed oxides; metallic type oxides; group I-IV, II-VI, III-VI, IV-VI, V-VI and VIII-VI binary chalcogenides; and group I-II-VI, II-II-VI, II-III-VI, II-VI-VI and V-II-VI ternary chalcogenides.

Transistors having partially recessed gates are constructed on silicon-on-insulator (SOI) semiconductor wafers provided with a buried oxide layer (BOX), for example, FD-SOI and UTBB devices. An epitaxially grown channel region relaxes constraints on the design of doped source and drain profiles. Formation of a partially recessed gate and raised epitaxial source and drain regions allow further improvements in transistor performance and reduction of short channel effects such as drain induced barrier lowering (DIBL) and control of a characteristic subthreshold slope. Gate recess can be varied to place the channel at different depths relative to the dopant profile, assisted by advanced process control. The partially recessed gate has an associated high-k gate dielectric that is initially formed in contact with three sides of the gate. Subsequent removal of the high-k sidewalls and substitution of a lower-k silicon nitride encapsulant lowers capacitance between the gate and the source and drain regions.

By performing multiple radiation-based anneal processes on the basis of less critical process parameters, the overall risk for creating anneal-induced damage, such as melting of gate portions, may be substantially avoided while nevertheless the respective degree of dopant activation may be enhanced for each individual anneal process. Consequently, the sheet resistance of advanced transistor devices may be reduced with a decreasing number of sequential anneal processes.

A thermal cycle includes: increasing a temperature from an initial temperature to a temperature T1 at an arbitrary rate R1 (° C./sec); holding the temperature at the temperature T1 for an arbitrary period t1 (sec); increasing the temperature from the temperature T1 to a temperature T2 at a rate R2 (° C./sec) of 1.0×10⁷ (° C./sec) or less; and holding the temperature at the temperature T2 for a period t2 (sec) of 50 msec or less. The thermal cycle thereafter includes: decreasing the temperature from the temperature T2 to the temperature T1 at a rate R1′ (° C./sec) of 1.0×10⁷ (° C./sec) or less; holding the temperature T1 for an arbitrary period t3 (sec); and decreasing the temperature from the temperature T1 to a final temperature at an arbitrary rate R2′ (° C./sec). Such a thermal cycle is successively repeated in a plurality of iterations.

A strained semiconductor material may be positioned in close proximity to the channel region of a transistor, such as an SOI transistor, while reducing or avoiding undue relaxation effects of metal silicides and extension implantations, thereby providing enhanced efficiency for the strain generation.

The present invention discloses a fabrication method of a vertical silicon nanowire field effect transistor having a low parasitic resistance, which relates to a field of an ultra-large-integrated-circuit fabrication technology. As compared with a conventional planar field effect transistor, on one hand the vertical silicon nanowire field effect transistor fabricated by the present invention can provide a good ability for suppressing a short channel effect due to the excellent gate control ability caused by the one-dimensional structure, and reduce a leakage current and a drain-induced barrier lowering (DIBL). On the other hand, an area of the transistor is further reduced and an integration degree of an IC system is increased.

A gate insulating film of a thin-film transistor is formed on a polysilicon film in which a source region and a drain region of the thin-film transistor are formed. A gate electrode of the thin-film transistor is formed on the gate insulating film. An insulating layer containing a silicon atom, a dangling bond of which is terminated with a nitrogen atom or an ON group, is provided in an interface between the polysilicon film and the gate insulating film.

A PMOS field effect transistor includes a substrate, a first nitride layer, a mesa structure, two gate oxide films, a gate stack layer and a second nitride layer. The substrate has a oxide layer and a first doping area. The first nitride layer is located on the oxide layer. The mesa structure includes a first strained Si—Ge layer, an epitaxial Si layer and a second strained Si—Ge layer. The first strained Si—Ge layer is located on the oxide layer and the first nitride layer. The epitaxial Si layer is located on the first strained Si—Ge layer. The second strained Si—Ge layer is located on the epitaxial Si layer. In the surface layer of the second strained Si—Ge layer, there is a second doping area. The two gate oxide films are located at two sides of the mesa structure.

On a semiconductor substrate, a transistor and a capacitor electrically connected to the transistor are formed, the capacitor having two electrodes made of metal and a capacitor dielectric layer between the two electrodes made of oxide dielectric material. A temporary protective film is formed over the capacitor, the temporary protective film covering the capacitor. The semiconductor substrate with the temporary protective film is subjected to a heat treatment in a reducing atmosphere. The temporary protective film is removed. The semiconductor substrate with the temporary protective film removed is subjected to a heat treatment in an inert gas atmosphere or in a vacuum state. A protective film is formed over the capacitor, the protective film covering the capacitor. With these processes, leak current of the capacitor can be reduced.

A method for manufacturing a transistor and a semiconductor device is provided. The method for manufacturing a transistor may comprise: defining an active area on a semiconductor substrate, and forming on the active area a gate stack or a dummy gate stack, a source/drain extension region, a spacer and a source/drain region, wherein the source/drain extension region is embedded in the active area and self-aligned on both sides of the gate stack or dummy gate stack, the spacer surrounds the gate stack or dummy gate stack, and the source/drain region is embedded in the active area and self-aligned outside the spacer; removing at least a portion of the spacer to expose a portion of the active area; and forming an interlayer dielectric layer which covers the gate stack or dummy gate stack, the spacer and the exposed active area, wherein the dielectric constant of the material of the interlayer dielectric layer is smaller than that of the removed material of the spacer. It is beneficial for reducing the capacitance between the gate region and the source/drain region as well as between the gate region and the contact plug.

A semiconductor device and a method for forming the same are provided. The method includes: providing a substrate having a gate structure and first spacers on both sidewalls of the gate structure formed on a top surface of the substrate; forming first openings in the substrate by using the first spacers as a mask, wherein the first openings are located on both sides of the gate structure; forming second openings by etching the first openings with an etching gas, wherein each of the second openings is an expansion of a corresponding one of the first openings toward the gate structure and extends to underneath an adjacent first spacer; and forming epitaxial layers in the first openings and the second openings.

The present invention provides a MOSFET capable of improving the basic performance of a transistor such as saturation current characteristics, input follow-up and an offleak current at high levels, and a manufacturing method thereof. The MOSFET comprises a semiconductor layer, a gate electrode formed over the semiconductor layer through a gate oxide film interposed therebetween, a pair of drain/source regions each provided at a position where the regions interpose a channel region lying below the gate oxide film therebetween inside the semiconductor layer and each having a conductivity type different from a conductivity type of the semiconductor layer, a pair of extension regions which are respectively provided adjacent to the drain/source regions at the position and which are identical in conductivity type to the drain/source regions and lower in impurity concentration than the drain/source regions, and an interposition layer having a conductivity type different from the conductivity type of the source region, the interposition layer being provided adjacent only to the source region and the extension region adjacent thereto inside the semiconductor layer.