Abstract: Short channel thin film transistors suffer from unacceptably high leakage currents. The invention provides an electronic device including a thin film transistor in which the length (20) of the channel of the transistor is 1 &mgr;m or less, and the mobility of the semiconductor material in the channel is less than 0.2 cm2/Vs. The selection of a low mobility semiconductor material results in acceptable off-current characteristics and its effect on the switching speed of the device is compensated for by the short channel length (20) of the device.

Abstract: The invention provides a method of manufacturing an electronic device including a vertical thin film transistor. A layer (8) of semiconductor material is provided over an insulated gate electrode (2). A negative resist (14) is used to define source and drain electrodes (26,28) which extend over the insulating layer (8) up to the step formed therein adjacent an edge (16A) of the gate electrode (2).

Abstract: An active matrix electroluminescent display device (2) comprises an array of display pixels (4) arranged in rows (6) and columns (8). Each pixel (4) comprises a current-driven electroluminescent display element (10). Each row (6) of pixels (4) shares a common line (20), currents through the display elements (10) of a row (6) of pixels passing along the common line (20). The width of each common line (20) tapers from one end (20a) to the other (20b), the common line (20) being coupled to row driver circuitry at the wider end (20a). The resistance of the common lines is thus reduced at the end of the common line near to the row driver circuitry, where the current flowing is derived from all pixels within the row. The invention thereby reduces voltage drops along the common line, which contribute to cross-talk between pixels within a row.

Abstract: An active matrix electroluminescent (EL) display device has an array of pixels (10) on a substrate (25) each comprising an EL display element (20) and a driving device (22) controlling drive current therethrough in a drive period based on a data signal applied in a preceding address period, and a drive circuit (16, 18) connected to the pixels via sets of address conductors (12, 14) for selecting the rows of pixels and supplying data signals to each selected row of pixels in a respective row address period. The data signals are provided by drive ICs (40). To reduce the number of ICs required, a multiplexing circuit (45) is integrated with the pixel array on the substrate (25) and connected between the drive IC outputs (41) and one set of address conductors (14) and is operable to apply data signals from an individual drive IC output to a respective associated plurality of address conductors in sequence in a row address period.

Abstract: A thin film capacitor is provided with a thin film protection element to protect the capacitor from damage that can result due to the occurrence of an electrostatic discharge event. The thin film capacitor includes two conductive film portions forming capacitor plates and a dielectric film forming the capacitor dielectric. The protection element may take the form of a thin film diode or a series of thin film diodes connected electrically in parallel with the thin film capacitor. The whole device can be fabricated using a stoichiometric silicon nitride layer to produce the capacitor dielectric and a non-stoichiometric silicon rich silicon nitride layer to provide the diode semiconductor material. One diode is formed by one capacitor plate, the semiconductor layer and an upper diode contact.

Abstract: A method of manufacturing a top-gate self-aligned thin film transistor involves the use of back exposure of a negative resist (26) using the lower source and drain electrode pattern (11, 12) as a photomask. A transparent amorphous silicon layer (24) is used as the gate electrode layer of the TFT structure, and the resistance of this gate electrode layer (24) is reduced by subsequent processing. For example, a silicide layer (32) may be formed over the gate electrode layer (24) which has the added advantage of reducing the transparency of the insulated gate structure (22, 24) of the TFT, thereby reducing the dependency of the TFT characteristics on light conditions.

Abstract: A transistor substrate for a liquid crystal display comprises an array of insulated-gate staggered TFTs and a capacitor (36) associated with each transistor. The gate insulator (400,420) comprises a first inorganic layer (400) and a second, polymer or spin-on glass layer (420), of which layers only the polymer or spin-on glass layer (420) extends to the capacitor (36) to define the capacitor dielectric.

Abstract: An active matrix electroluminescent display device (2) comprises an array of display pixels (4) arranged in rows (6) and columns (8). Each pixel (4) comprises a current-driven electroluminescent display element (10). Each row (6) of pixels (4) shares a common line (20), currents through the display elements (10) of a row (6) of pixels passing along the common line (20). The width of each common line (20) tapers from one end (20a) to the other (20b), the common line (20) being coupled to row driver circuitry at the wider end (20a). The resistance of the common lines is thus reduced at the end of the common line near to the row driver circuitry, where the current flowing is derived from all pixels within the row. The invention thereby reduces voltage drops along the common line, which contribute to cross-talk between pixels within a row.

Abstract: An autostereoscopic display apparatus comprises a display device (10), for example a matrix LC display panel, for producing a display output consisting of rows and columns of pixels (12) and lenticular means (15) at the output side of the display device comprising an array of lenticular elements (16) through which different groups of pixels, forming one or more stereoscopic pairs, are seen by respective eyes of a viewer. The lenticular means includes electro-optic material (38) having an electrically--alterable refractive index and which can be selectively switched to remove the action of the lenticular elements thereby allowing high resolution 2-D images to be viewed.

Abstract: A liquid crystal display device (10) capable of displaying dark characters on a light background, for example a paper white type display, having an LC medium (20), such as PDLC material, switchable between a state in which ambient light incident on one side is back scattered towards a viewer and a state in which incident visible light is transmitted through the medium to a light absorber at the other side so that a viewer perceives a dark display, and in which a photovoltaic structure (25) is used as the light absorber for generating an output voltage in response to the visible light transmitted thereto. In equipment such as a portable computer or the like, the generated power can be utilised to supplement a battery power supply (45).

Abstract: A light sensing array device including an array of photoelectric light sensing elements (10) individually addressable via sets of address conductors (12, 14) for use, for example, in image sensing or data input using a light pen, which is operable also in a power generating mode in which sensing elements in the array produce electrical power in the manner of a solar cell. To this end, the sets of address conductors are selectively connected via switching means (20, 21, 37, 38) to power output terminals (42, 43). The generated power may be used to supplement a power supply, e.g. using a battery pack, of the device or of electronic apparatus, such as a notebook computer, incorporating the device.

Abstract: A semiconductor body (2) has an active region (6) of n conductivity type formed of a material having a relatively low mass, high mobility conduction band main minimum and at least one relatively high mass, low mobility conduction band satellite minimum and an injector region (9) defining a potential barrier (P) to the flow of electrons into the active region (6) of a height such that, in operation of the device, electrons with sufficient energy to surmount the barrier (P) provided by the injector region (9) are emitted into the active region (6) with an energy comparable to that of the at least one relatively high mass, low mobility conduction band satellite minimum. An electron containing well region (10a, 10b) of a material different from that of the active region (6) and of the injector region (9) is provided between the injector region (9) and the active region (6) for inhibiting the spread of a depletion region into the active region (6) during operation of the device.

Abstract: A method for simulating distributed effects within a device such as a power semiconductor device, more particularly a method for generating a simulation program for automatically simulating time dependent characteristics of a device to enable the operation of the device within a larger circuit to be simulated by a circuit simulator program which contains a computer model of the device to facilitate the designing of circuits incorporating such a device is described.

Abstract: A dual-gate insulated gate field effect device (1) such as a MOS tetrode has an active device area (3) in which adjacent source regions (5) are separated by and spaced apart from an intervening drain region (6) to define a respective conduction channel region (7) between each source and drain region (5 and 6). An insulated gate structure (10) has first insulated gate sections (11) forming an inner insulated gate (110) connected so as to surround each drain region 6 and second insulated gate sections (12) provided between the first insulated gate sections (11) and the source regions (5) and forming an outer insulated gate (120). Ends (11a,12a) of the insulated gate sections (11 and 12) extend onto the surrounding field oxide (4) to connect with respective first and gate conductors (13 and 14).

Abstract: A transferred electron effect device has a semiconductor body with an active region (2) of n conductivity type formed of a semiconductor material having a relatively low mass, high mobility conduction band main minimum and at least one relatively high mass, low mobility conduction band satellite minimum, and an injection zone (3) adjoining the active region (2) for causing electrons to be emitted, under the influence of an applied electric field, from the injection zone (3) into the active region (2) with an energy comparable to that of the relatively high mass, low mobility, conduction band satellite minima of the active region.

Abstract: A semiconductor device is formed by a semiconductor body (1) having a substrate (2) on which is provided a channel-defining region (10) extending between input and output regions (20) and (21). The channel-defining region (10) has a channel layer (11) forming a heterojunction (12) with at least one barrier layer (13) to form within the channel layer (11) a two-dimensional free charge carrier gas (14) of one conductivity type for providing a conduction channel (14) controllable by a gate electrode (25). A potential well region (30) is provided between the substrate (2) and the channel-defining region (10).

Abstract: A transferred electron effect device (1) has adjacent its cathode contact region (3) an injection zone (60) defining a potential barrier (P) for causing electrons to be emitted, under the influence of an electric field applied between the cathode and anode contact regions (3 and 4), into the active region (5) of the device with an energy comparable to that of a relatively high mass, low mobility satellite minimum (L) of the active region (5). The anode contact region (4), active region (5), injection zone (60) and cathode contact region (3) are grown sequentially, for example using molecular beam epitaxy, on a substrate which is then selectively removed to expose the anode contact region. A heat sink (70) is provided in thermal contact with the anode contact region (4). Providing the heat sink (70) in thermal contact with the anode contact region (4) rather than the cathode contact region (3) enables a significant increase in rf output power.

Abstract: A semiconductor body (1) is provided by growing epitaxial layers of semiconductor material on a substrate placed within a processing chamber and forming a mesa structure (3) on an upper epitaxial layer (2). The mesa structure (3) is formed by epitaxially growing, with the semiconductor body (1) still within the processing chamber, a first layer (4) of a semiconductor material different from that of the upper layer (2) on the upper layer (2) and the opening a window (5) in the first layer (4) to expose an area (2a) of the upper layer (2). A further layer (6) of a semiconductor material different from that of the first layer (4) is then epitaxially grown on the first layer (4) and on the said area (2a) of the upper layer. The first layer (4) is then selectively etched so as to remove the first layer (4) and the part of the further layer (6) carried by the first layer ( 14) leaving the remainder (60a, 60b) of the further layer (6) in the window (5) to form the mesa structure (3).

Abstract: A shapeable composition comprising a homogeneous mixture of (a) at least one particulate ferrite material having magnetic properties, (b) at least one water-soluble or water-dispersible organic polymeric material, and (c) water, in the composition the components (a), (b) and (c) being present in a proportion by volume of the composition of respectively, 40 to 90%, 2 to 25%, and not more than 60%, a product produced therefrom, and a process for producing said product by removing water from the composition. The composition optionally contains additives capable of insolubilizing the organic polymeric material with respect to water.