Abstract: A nitride-based light emitting device capable of achieving an enhancement in light emission efficiency and an enhancement in reliability is disclosed. The nitride-based light emitting device includes a light emitting layer including a quantum well layer and a quantum barrier layer, and a stress accommodating layer arranged on at least one surface of the quantum well layer of the light emitting layer.

Abstract: Quantum well thermoelectric modules and a low-cost method of mass producing the modules. The devices are comprised of n-legs and p-legs, each leg being comprised of layers of quantum well material in the form of very thin alternating layers. In the n-legs the alternating layers are layers of n-type semiconductor material and electrical insulating material. In the p-legs the alternating layers are layers of p-type semiconductor material and electrical insulating material. Both n-legs and p-legs are comprised of materials providing similar thermal expansion. In preferred embodiments the layers, referred to as super-lattice layers are about 4 nm to 20 nm thick. The layers of quantum well material is separated by much larger layers of thermal and electrical insulating material such that the volume of insulating material in each leg is at least 20 times larger than the volume of quantum well material.

Abstract: Highly uniform silica nanoparticles can be formed into stable dispersions with a desirable small secondary particle size. The silican particles can be surface modified to form the dispersions. The silica nanoparticles can be doped to change the particle properties and/or to provide dopant for subsequent transfer to other materials. The dispersions can be printed as an ink for appropriate applications. The dispersions can be used to selectively dope semiconductor materials such as for the formation of photovoltaic cells or for the formation of printed electronic circuits.

Abstract: Provided are a light emitting diode (LED) and a method for manufacturing the same. The LED includes an n-type semiconductor layer, an active layer, and a p-type semiconductor layer. The active layer includes a well layer and a barrier layer that are alternately laminated at least twice. The barrier layer has a thickness at least twice larger than a thickness of the well layer.

Abstract: A semiconductor device includes a channel region; a gate dielectric over the channel region; a gate electrode over the gate dielectric; and a first source/drain region adjacent the gate dielectric. The first source/drain region is of a first conductivity type. At least one of the channel region and the first source/drain region includes a superlattice structure. The semiconductor device further includes a second source/drain region on an opposite side of the channel region than the first source/drain region. The second source/drain region is of a second conductivity type opposite the first conductivity type. At most, one of the first source/drain region and the second source/drain region comprises an additional superlattice structure.

Abstract: A hosting structure of nanometric components is described advantageously comprising: a substrate; n array levels on said substrate, with n?2, arranged consecutively on growing and parallel planes, each including a plurality of conductive spacers alternated with a plurality of insulating spacers and substantially perpendicular to said substrate, with definition between consecutive conductive spacers of at least a gap, conductive spacers of consecutive array levels lying on distinct and parallel planes, said gaps of different array levels being at least partially aligned along a direction substantially perpendicular to said substrate with definition of a plurality of transversal hosting seats extended along said direction and suitable for hosting at least a nanometric component. A nanometric electronic device is also described comprising such a hosting structure and a method for realizing it.

Abstract: A semiconductor device may include a semiconductor substrate having a surface, a shallow trench isolation (STI) region in the semiconductor substrate and extending above the surface thereof, and a superlattice layer adjacent the surface of the semiconductor substrate and comprising a plurality of stacked groups of layers. More particularly, each group of layers of the superlattice layer may include a plurality of stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions. Moreover, at least some atoms from opposing base semiconductor portions may be chemically bound together with the chemical bonds traversing the at least one intervening non-semiconductor monolayer.

Abstract: A nitride semiconductor light emitting device, and a method of manufacturing the same are disclosed. The nitride semiconductor light emitting device includes a substrate, an n-type nitride semiconductor layer disposed on the substrate and including a plurality of V-shaped pits in a top surface thereof, an active layer disposed on the n-type nitride semiconductor layer and including depressions conforming to the shape of the plurality of V-shaped pits, and a p-type nitride semiconductor layer disposed on the active layer and including a plurality of protrusions on a top surface thereof. Since the plurality of V-shaped pits are formed in the top surface of the n-type nitride semiconductor layer, the protrusions can be formed on the p-type nitride semiconductor layer as an in-situ process. Accordingly, the resistance to ESD, and light extraction efficiency are enhanced.

Abstract: An edge-sealed, encapsulated environmentally sensitive device. The device includes an environmentally sensitive device, and at least one edge-sealed barrier stack. The edge-sealed barrier stack includes a decoupling layer and at least two barrier layers. The environmentally sensitive device is sealed between an edge-sealed barrier stack and either a substrate or another edge-sealed barrier stack. A method of making the edge-sealed, encapsulated environmentally sensitive device is also disclosed.

Abstract: A semiconductor device may include a first monocrystalline layer comprising a first material having a first lattice constant. A second monocrystalline layer may include a second material having a second lattice constant different than the first lattice constant. The device may also include a lattice matching layer between the first and second monocrystalline layers and comprising a superlattice. The superlattice may include a plurality of groups of layers, and each group of layers may include a plurality of stacked semiconductor monolayers defining a semiconductor base portion and at least one non-semiconductor monolayer thereon. The at least one non-semiconductor monolayer may be constrained within a crystal lattice of adjacent base semiconductor portions, and at least some semiconductor atoms from opposing base semiconductor portions may be chemically bound together through the at least one non-semiconductor monolayer therebetween.

Abstract: The subject invention comprises the realization of P-on-N type II InAs/GaSb superlattice photodiodes. A high-quality InAsSb layer lattice-mismatched to GaSb is used as a buffer to prepare the surface of the substrate prior to superlattice growth. The InAsSb layer also serves as an effective n-contact layer. The contact layer has been optimized to improve device performance, most notably performance that is similar to traditional N-on-P structures.

Abstract: A method of producing silicon nanowires includes providing a substrate in the form of a doped material; formulating an etching solution; and applying an appropriate current density for an appropriate length of time. Related structures and devices composed at least in part from silicon nanowires are also described.

Abstract: A semiconductor device includes a channel region; a gate dielectric over the channel region; a gate electrode over the gate dielectric; and a first source/drain region adjacent the gate dielectric. The first source/drain region is of a first conductivity type. At least one of the channel region and the first source/drain region includes a superlattice structure. The semiconductor device further includes a second source/drain region on an opposite side of the channel region than the first source/drain region. The second source/drain region is of a second conductivity type opposite the first conductivity type. At most, one of the first source/drain region and the second source/drain region comprises an additional superlattice structure.

Abstract: A semiconductor device may include a semiconductor substrate and at least one non-volatile memory cell. The at least one memory cell may include spaced apart source and drain regions, and a superlattice channel including a plurality of stacked groups of layers on the semiconductor substrate between the source and drain regions. Each group of layers of the superlattice channel may include a plurality of stacked base semiconductor monolayers defining a base semiconductor portion and an energy band-modifying layer thereon, which may include at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions. A floating gate may be adjacent the superlattice channel, and a control gate may be adjacent the second gate insulating layer.

Abstract: An improved photodiode and method of producing an improved photodiode comprising doping an InAs layer of an InAs/GaSb region situated on top of an InAs/GaSb:Be superlattice and below an InAs:Si/GaSb regions such that the quantum efficiency of the photodiode increases and dominant dark current mechanisms change from diffusion to band-to-band tunneling as the InAs layer is doped with Beryllium.

Abstract: A ZnO-containing semiconductor layer, doped with Se, has an emission peak wavelength in visual light and has a band gap equivalent to a band gap of ZnO.

Abstract: Semiconductor structures and methods are provided for a semiconductor device (40) employing a superjunction structure (41) and overlying trench (91) with embedded control gate (48). The method comprises, forming (52-6, 52-9) interleaved first (70-1, 70-2, 70-3, 70-4, etc.) and second (74-1, 74-2, 74-3, etc.

Abstract: A GaN based semiconductor light-emitting device is provided. The light-emitting device includes a first GaN based compound semiconductor layer of an n-conductivity type; an active layer; a second GaN based compound semiconductor layer; an underlying layer composed of a GaN based compound semiconductor, the underlying layer being disposed between the first GaN based compound semiconductor layer and the active layer; and a superlattice layer composed of a GaN based compound semiconductor doped with a p-type dopant, the superlattice layer being disposed between the active layer and the second GaN based compound semiconductor layer.

Abstract: A semiconductor device may include a substrate, an insulating layer adjacent the substrate, and a semiconductor layer adjacent a face of the insulating layer opposite the substrate. The device may further include source and drain regions on the semiconductor layer, a superlattice adjacent the semiconductor layer and extending between the source and drain regions to define a channel, and a gate overlying the superlattice. The superlattice may include a plurality of stacked groups of layers, with each group of layers including a plurality of stacked base semiconductor monolayers defining a base semiconductor portion and an energy band-modifying layer thereon. The energy band-modifying layer may include at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions.

Abstract: A GaN based semiconductor light-emitting device is provided. The light-emitting device includes a first GaN based compound semiconductor layer of an n-conductivity type; an active layer; a second GaN based compound semiconductor layer; an underlying layer composed of a GaN based compound semiconductor, the underlying layer being disposed between the first GaN based compound semiconductor layer and the active layer; and a superlattice layer composed of a GaN based compound semiconductor doped with a p-type dopant, the superlattice layer being disposed between the active layer and the second GaN based compound semiconductor layer.

Abstract: A method for making a semiconductor device may include forming a plurality of shallow trench isolation (STI) regions in a semiconductor substrate. Further, a plurality of layers may be deposited over the substrate to define respective superlattices over the substrate between adjacent STI regions and to define respective non-monocrystalline regions over the STI regions. The method may further include selectively removing at least portions of the non-monocrystalline regions using at least one active area (AA) mask.

Abstract: The present invention provides a single crystal wafer, wherein the main surface has a plane or a plane equivalent to a plane tilting with respect to a [100] axis of single crystal by angles of ? (0°<?<90°) for the [011] direction, ? (0°<?<90°) for the [01-1] direction and ? (0°??<45°) for the [10-1] or [101] direction. Thus, a single crystal wafer that can sufficiently bear device production processes even with a small wafer thickness is provided and thereby loss of single crystal raw material is reduced. Further, by using such a wafer, MIS type semiconductor devices and solar cells are provided at a low cost.

Abstract: A semiconductor device may include a substrate and at least one MOSFET adjacent the substrate including a superlattice. The superlattice may include a plurality of stacked groups of layers and a semiconductor cap layer on an uppermost group of layers. Each group of layers of the superlattice may comprise a plurality of stacked base semiconductor monolayers defining a base semiconductor portion and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions. The MOSFET may further include source, drain, and gate regions defining a channel through at least a portion of the semiconductor cap layer.

Abstract: Embodiments of the present invention generally relate to solar cells and methods and apparatuses for forming the same. More particularly, embodiments of the present invention relate to thin film multi-junction solar cells and methods and apparatuses for forming the same.

Abstract: The conventional detection technique has the following problems in detecting interference fringes: (1) Setting and adjustment are complex and difficult to conduct; (2) A phase image and an amplitude image cannot be displayed simultaneously; and (3) Detection efficiency of electron beams is low. The invention provides a scanning interference electron microscope which is improved in detection efficiency of electron beam interference fringes, and enables the user to observe electric and magnetic information easily in a micro domain of a specimen as a scan image of a high S/N ratio under optimum conditions.

Abstract: This disclosure relates to a system and method for creating nanowires. A nanowire can be created by exposing layers of material in a superlattice and dissolving and transferring material from edges of the exposed layers onto a substrate. The nanowire can also be created by exposing layers of material in a superlattice and depositing material onto edges of the exposed layers.

Abstract: A strained transistor includes a silicon transistor, an encapsulating layer of silicon insulating material with an outer surface, and a stress inducing multilayer cap deposited on the outer surface of the encapsulating layer with at least two layers including a layer of rare earth oxide and a layer including silicon. The stress inducing cap can be designed to provide either compressive strain or tensile strain and virtually any desired amount of strain without producing dislocations, defects, and fractures in the structure.

Abstract: A semiconductor device may include a semiconductor substrate and at least one metal oxide semiconductor field-effect transistor (MOSFET). The MOSFET may include spaced apart source and drain regions on the semiconductor substrate, and a superlattice including a plurality of stacked groups of layers on the semiconductor substrate between the source and drain regions. The superlattice may have upper portions extending above adjacent upper portions of the source and drain regions, and lower portions contacting the source and drain regions so that a channel is defined in lower portions of said superlattice. Furthermore, each group of layers of the superlattice may include a plurality of stacked base semiconductor monolayers defining a base semiconductor portion and an energy band-modifying layer thereon. The energy-band modifying layer may include at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor. A gate may overly the superlattice.

Abstract: An edge-sealed, encapsulated environmentally sensitive device. The device includes at least one initial barrier stack, an environmentally sensitive device, and at least one additional barrier stack. The barrier stacks include at least one decoupling layer and at least one barrier layer. The environmentally sensitive device is sealed between the at least one initial barrier stack and the at least one additional barrier stack. A method of making the edge-sealed, encapsulated environmentally sensitive device is also disclosed.

Abstract: A capillary for a mass spectrometry system is described. The capillary comprises a channel and a tip, and at least one of the channel and the tip comprises a nanowire material.

Abstract: A method for enhancing spatial resolution of a transmission electron microscopy TEM) system configured for electron holography. In an exemplary embodiment, the method includes configuring a first lens to form an initial virtual source with respect to an incident parallel beam, the initial virtual source positioned at a back focal plane of said first lens. A second lens is configured to form an intermediate virtual source with respect to the incident parallel beam, the position of said intermediate virtual source being dependent upon a focal length of the first lens and a focal length of the second lens. A third lens is configured to form a final virtual source with respect to the incident parallel beam, wherein the third lens has a focal length such that a front focal plane of the third lens lies beyond the position of the intermediate virtual source, with respect to a biprism location.

Abstract: Disclosed is a natural-superlattice homologous single-crystal thin film, which includes a complex oxide which is epitaxially grown on either one of a ZnO epitaxial thin film formed on a single-crystal substrate, the single-crystal substrate after disappearance of the ZnO epitaxial thin film and a ZnO single crystal. The complex oxide is expressed by the formula: M1M2O3 (ZnO)m, wherein M1 is at least one selected from the group consisting of Ga, Fe, Sc, In, Lu, Yb, Tm, Er, Ho and Y, M2 is at least one selected from the group consisting of Mn, Fe, Ga, In and Al, and m is a natural number of 1 or more. A natural-superlattice homologous single-crystal thin film formed by depositing the complex oxide and subjecting the obtained layered film to a thermal anneal treatment can be used in optimal devices, electronic devices and X-ray optical devices.

Abstract: A super-lattice thermoelectric device. The device includes p-legs and n-legs, each leg having a large number of alternating layers of two materials with differing electron band gaps. The n-legs in the device are comprised of alternating layers of silicon and silicon germanium. The p-legs includes alternating layers of B4C and B9C. In preferred embodiments the layers are about 100 angstroms thick. Applicants have fabricated and tested a first Si/SiGe (n-leg) and B4C/B9C (p-leg) quantum well thermocouple. Each leg was only 11 microns thick on a 5 micron Si substrate. Nevertheless, in actual tests the thermocouple operated with an amazing efficiency of 14 percent with a Th of 250 degrees C. Thermoelectric modules made according to the present invention are useful for both cooling applications as well as electric power generation. This preferred embodiment is a thermoelectric 10×10 egg crate type module about 6 cm×6 cm×0.

Abstract: A Si/C superlattice useful for semiconductor devices comprises a plurality of epitaxially grown silicon layers alternating with carbon layers respectively adsorbed on surfaces of said silicon layers. Structures and devices comprising the superlattice and methods are described.

Abstract: A metamorphic device including a substrate structure upon which a semiconductor device can be formed. In the metamorphic device, a buffer layer matching a substrate lattice constant is formed at normal growth temperatures and a thin grading layer which grades past the desired lattice constant is configured at a low temperature. A reverse grading layer grades the lattice constant back to match a desired lattice constant. Thereafter, a thick layer is formed thereon, based on the desired lattice constant. Annealing can then occur to isolate dislocated material in at least the grading layer and the reverse grading layer. Thereon a strained layer superlattice is created upon which a high-speed photodiode or other semiconductor device can be formed.

Abstract: The present invention discloses a semiconductor memory device having a multiple tunnel junction pattern and a method of forming the same. The semiconductor memory device includes a unit cell composed of planar transistor and vertical transistors. The planar transistor includes first and second conductive regions formed at predetermined regions of a semiconductor substrate and a storage node stacked on a channel region therebetween. The vertical transistor includes a storage node, a multiple tunnel junction pattern stacked thereon, a data line stacked thereon, and a word line for covering both sidewalls of the storage node and the multiple tunnel junction pattern. Width of the multiple tunnel junction pattern is narrower than the storage node and data lines. Semiconductor layers and tunnel oxide layers are alternately and repeatedly stacked and anisotropically etched to form the multiple tunnel junction pattern of narrow width while forming the data line and the storage node.

Abstract: Methods of forming a nano-scale electronic and optoelectronic devices include forming a substrate having a semiconductor layer therein and a substrate insulating layer on the semiconductor layer. An etching template having a first array of non-photolithographically defined nano-channels extending therethrough, is formed on the substrate insulating layer. This etching template may comprise an anodized metal oxide, such as an anodized aluminum oxide (AAO) thin film. The substrate insulating layer is then selectively etched to define a second array of nano-channels therein. This selective etching step preferably uses the etching template as an etching mask to transfer the first array of nano-channels to the underlying substrate insulating layer, which may be thinner than the etching template. An array of semiconductor nano-pillars is then formed in the second array of nano-channels. The semiconductor nano-pillars in the array may have an average diameter in a range between about 8 nm and about 50 nm.

Abstract: A structure having pores includes a first layer containing alumina, a second layer that includes at least one of Ti, Zr, Hf, Nb, Ta, Mo, W and Si, and a third layer with electrical conductivity, in this order, wherein the first and second layers have pores.

Abstract: A method for controlling electric conduction on nanoscale wires is disclosed. The nanoscale wires are provided with controllable regions axially and/or radially distributed. Controlling those regions by means of microscale wires or additional nanoscale wires allows or prevents electric conduction on the controlled nanoscale wires. The controllable regions are of two different types. For example, a first type of controllable region can exhibit a different doping from a second type of controllable region. The method allows one or more of a set of nanoscale wires, packed at sublithographic pitch, to be independently selected.

Abstract: A semiconductor component for generating a polychromatic electromagnetic radiation has a semiconductor chip with a first semiconductor layer and a second semiconductor layer, which is provided adjacent to the first semiconductor layer and has an electroluminescent region. The electroluminescent region emits electromagnetic radiation of a first wavelength. The first semiconductor layer includes a material which, when excited with the electromagnetic radiation of the first wavelength, re-emits radiation with a second wavelength which is longer than the first wavelength.

Abstract: A semiconductor device includes a substrate, and at least one MOSFET adjacent the substrate. The MOSFET may include a superlattice channel that, in turn, includes a plurality of stacked groups of layers. The MOSFET may also include source and drain regions laterally adjacent the superlattice channel, and a gate overlying the superlattice channel for causing transport of charge carriers through the superlattice channel in a parallel direction relative to the stacked groups of layers. Each group of the superlattice channel may include a plurality of stacked base semiconductor monolayers defining a base semiconductor portion, and an energy band-modifying layer thereon. The energy-band modifying layer may include at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions so that the superlattice channel may have a higher charge carrier mobility in the parallel direction than would otherwise occur.

Abstract: An edge-sealed barrier film composite. The composite includes a substrate and at least one initial barrier stack adjacent to the substrate. The at least one initial barrier stack includes at least one decoupling layer and at least one barrier layer. One of the barrier layers has an area greater than the area of one of the decoupling layers. The decoupling layer is sealed by the first barrier layer within the area of barrier material. An edge-sealed, encapsulated environmentally sensitive device is provided. A method of making the edge-sealed barrier film composite is also provided.

Abstract: The present invention is related to methods and apparatus to produce a memory cell or resistance variable material with improved data retention characteristics and higher switching speeds. In a memory cell according to an embodiment of the present invention, silver selenide and a chalcogenide glass, such as germanium selenide (GexSe(1?x)) are combined in an active layer, which supports the formation of conductive pathways in the presence of an electric potential applied between electrodes. Advantageously, embodiments of the present invention can be fabricated with relatively wide ranges for the thicknesses of the silver selenide and glass layers.

Abstract: A semiconductor device includes a substrate, and at least one MOSFET adjacent the substrate. The MOSFET may include a superlattice channel that, in turn, includes a plurality of stacked groups of layers. The MOSFET may also include source and drain regions laterally adjacent the superlattice channel, and a gate overlying the superlattice channel for causing transport of charge carriers through the superlattice channel in a parallel direction relative to the stacked groups of layers. Each group of the superlattice channel may include a plurality of stacked base semiconductor monolayers defining a base semiconductor portion, and an energy band-modifying layer thereon. The energy-band modifying layer may include at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions so that the superlattice channel may have a higher charge carrier mobility in the parallel direction than would otherwise occur.

Abstract: The self inductance associated with a capacitance A52 in a superconductor integrated circuit (FIG. 1) is reduced by adding a layer of superconductor metal (A54) overlying the capacitor, effectively producing a negative inductance to counteract the self-inductance of the capacitor leads, thereby reducing inductance of the circuit. As a result it possible to transfer a single flux quantum (“SFQ”) pulse through the capacitor. Capacitors (19 and 25 FIG. 5) of the foregoing type are incorporated in superconductor integrated circuit SFQ transmission lines (FIG. 5) to permit SQUID-to-SQUID transfer of SFQ pulses, while maintaining the circuit grounds of the respective SQUIDs in DC isolation. Bias current (10) may be supplied to multiple SQUIDs (1 & 3, 7 & 9 FIG. 5) serially, reducing the supply current required previously for operation of multiple SQUIDs.

Abstract: A method for fabricating chalcogenide materials on substrates, which reduces and/or eliminates agglomeration of materials on the chalcogenide materials; and system and devices for performing the method, semiconductor devices so produced, and machine readable media containing the method. One method disclosed includes forming a first layer, forming a second layer on the first layer, forming a third layer on the second layer, wherein the third layer is essentially transparent to irradiation, and irradiating the second layer through the third layer to cause the second layer to diffuse into the first layer thereby creating an integral layer of materials from the first and second layers.

Abstract: An integrated circuit is provided with one or more connectors which allow an opto-electric device to be mounted on the integrated circuit directly on top of or underneath of it. Multiple opto-electric device interface regions can be defined on the integrated circuit such that an opto-electric device can be connected in a variety of directions or such that multiple opto-electric devices can be connected. In addition, an opto-electric device interface may be provided that causes the opto-electric device's leads to be directed to the corresponding integrated circuit lead in the shortest possible distance regardless of how the opto-electric device is positioned. Also disclosed is a substrate-mounted optical transmission system that may be used in connection with the opto-electric device.

Abstract: A method for improving a doping profile using gas phase doping is described. In the method, silicon nitride and/or products of decomposition from a silicon nitride deposition are introduced in a process chamber before or during the actual gas phase doping. This allows the doping profile to be significantly improved.

Abstract: It is an object of the invention to provide a process for producing insulations for electrical conductors by means of powder coating, which results in aging which is improved compared to glass-mica or casting-resin insulation. It is also intended to describe a powder which is suitable for such a process. For this purpose, the powder is applied a number of times in succession, in the form of individual layers which follow one another, until a layer thickness of ≦10 mm is reached, and each of the individual layers undergoes intermediate heat curing before the next individual layer is applied. The intermediate curing of each individual layer uses a curing time which corresponds to 2-10 times the gel time of the powder used. Finally, the entire insulation undergoes final curing. The result of an electrical life test carried out on various specimens insulated with epoxy-resin powder which contains fine filler and has been applied in accordance with the invention is illustrated in the only FIGURE.

Abstract: A semiconductor structure for integrated control of an active subcircuit includes a monocrystalline silicon substrate, an amorphous oxide material overlying the monocrystalline silicon substrate, a monocrystalline perovskite oxide material overlying the amorphous oxide material, a monocrystalline compound semiconductor material overlying the monocrystalline perovskite oxide material, the active subcircuit in the monocrystalline compound semiconductor material, and a bias subcircuit in the monocrystalline silicon substrate and electrically coupled to the active subcircuit to bias the active subcircuit.