U.S. Philips Corporation

Other

Arthur M Hoeberechts

Gerardus G Van Gorkom

Harm Tolner

Marino G Carasso

Karel D Van Der Mast

Petrus J Peters

Henricus A Van Hal

Jan Dieleman

Nicolaas Lambert

John M Shannon

Gerard E Van Rosmalen

Aart A Van Gorkum

Gerjan F Van De Walle

Paulus Philippus Schampers

Antonius J Van Der Bolt

Petrus A Van Der Heide

Bart Van Der Eijk

Johannes A Van Leunen

Walter H Kuhl

Date J Noorlag

A planar electron-optical lens is obtained on a semiconductor cathode surface by providing an extra electrode (16) around the gate electrode (14). Dependent on the applied voltage, this configuration operates, for example, as a positive lens which supplies parallel beams without dispersion, suitable for thin, flat display devices. A large positioning tolerance is obtained due to the inherent magnification of the beam diameter in the semiconductor device, while a grid can be dispensed with.

Device for generating electrons, and display device

The efficiency of semiconductor cathodes based on avalanche breakdown is enhanced by using '.delta.-doping' structures. The quantization effects introduced thereby decrease the effective work function. A typical cathode structure has an n-type semiconductor region and a first p-type semiconductor region, with the n-type region having a thickness of at most 4 nanometers.

Semiconductor device for generating an electron current

The invention relates to the combination of a support and a semiconductor body and to a method of manufacturing same, in which a deformable metal layer is disposed between the semiconductor body and the support. The semiconductor body is connected to the support by pressing the semiconductor body and the support against each other under pressure after heating the metal layer. The semiconductor body is then provided at its surface facing the support with at least one projecting part, which is embedded in the metal layer.

Combination of a support and a semiconductor body and method of

An electron beam apparatus comprising a semiconductor electron emitter whose emissive surface dimensions are determined by dimensions of a p-n junction provided in the semiconductor element. By optimizing the dimensions of the emissive surface in relation to the electron-optical properties of the apparatus, an emitter is realized which combines optimum beam formation or imaging with a sufficiently large beam current and a high beam current density as required by the apparatus.

Electron beam apparatus comprising a semiconductor electron emitter

A radiation-sensitive semiconductor device has a high-ohmic semiconductor wafer with a thicker edge portion and a thinner central portion, in which a photodiode is located. The surface opposite to the photodiode is provided with a highly-doped contact layer, on which a metal layer is provided. The central portion is so thin that at a low photodiode voltage the depletion zone of the photodiode extends as far as the contact layer. According to the invention, the device includes an active screening diode, which extends both in the edge portion and in the central portion and whose depletion zone extends in the operating condition in the central portion as far as the contact layer. As a result, diffusion of charge carriers from the edge portion to the photodiode is avoided.

Radiation-sensitive semiconductor device with active screening diode

A flat thin display device is obtained by means of cold cathodes (10) in which each cathode provides the electron emission (14) for a (part of a) column of pixels. The emissive surface is preferably chosen to be parallel to the front and rear walls (3, 4) of the display device so that the cathodes cannot degrade due to an ion bombardment.

Display device with multiplicity of closely spaced electron beams

By providing an intrinsic semiconductor region in a reverse biased junction cathode between an n-type surface region and a p-type zone, a maximum field is present over the intrinsic region in the operating condition. The efficiency of the cathode is increased because avalanche multiplication can now occur over a greater distance, while in addition electrons to be emitted at a sufficient energy are generated by means of tunneling.

Semiconductor electron-current generating device having improved cathode

In a radiation-sensitive semiconductor device, for example a quadrant diode, having several rectifying junctions, the mutual distance between these junctions can be considerably reduced by keeping the junctions cut off by means of circuit elements in such manner that associated depletion regions touch each other. Charge carriers generated between two junctions are substantially always collected by the appropriate junction. With this arrangement, low crosstalk and good high-frequency properties can be realized. Furthermore, the semiconductor body in which the rectifying junctions are realized may comprise further circuit elements, which permits integration of the radiation-sensitive semiconductor device with other elements.

Radiation-sensitive semiconductor device

In a semiconductor cathode, the electron-emitting part of a pn junction is provided in the tip of a projecting portion of the semiconductor surface which is situated within an opening in an insulating layer on which an acceleration electrode is disposed. Due to the increased electric field near the tip, a reduction of the work function (Schottky effect) is obtained. As a result, cathodes can be realized in which a material reducing the work function, such as caesium, may be either dispensed with or replaced, if required, by another material, which causes lower work function, but is less volatile. The field strength remains so low that no field emission occurs and serarate cathodes can be driven individually, which is favorable for applications in electron microscopy and electron lithography.

Semiconductor device having a cold cathode

In a position-sensitive radiation detector having a semiconductor body which at least in the operating condition comprises a high-ohmic zone (11) between two radiation-sensitive diodes (6) provided with connection electrodes (9), a high-ohmic zone (11) between two semiconductor zones (6) provided with connection electrodes (9), can be apparently centered by varying the voltages at the connection electrodes (9) in such a manner that the photocurrents through the diodes (6) are the same. The signals derived therefrom can be supplied to measuring and control systems for, for example, optical reading and writing apparatus and other measuring apparatus.

Device for determining the position of a radiation beam

An electron-emitting surface is provided with a material reducing the electron work function, which is obtained from a suitable reaction. The reaction mixture or the product to be decomposed, for example CsN.sub.3, is present in a surface depression of a semiconductor body, while one or more pn junctions act as a heating diode. Upon heating, cesium is released and deposited on the electron-emitting surface.

Device for electron emission including device for providing work

In an analogue-to-digital converter based on the principle of deflection of an electron beam striking a target plate, the number of diodes in the target plate is doubled. The target plate is covered with a metal pattern in a manner so that a complementary digital signal is available besides the original digital signal. Thus, a faster conversion can be achieved. The metal pattern is extended so that extreme values of the voltage to be converted are also detected in a simple manner.

Device for signal processing and target plate for such a device

A device for recording or displaying images or for electron lithographic or electron microscopic uses, comprising in an evacuated envelope (1) a target (7) on which at least one electron beam (6) is focussed. This beam is generated by means of a semiconductor device (10) which comprises an electrically insulating layer (42) having an aperture (38) through which the beam passes. The layer carries at least four beam-forming electrodes (43 through 50) which are situated at regular intervals around the aperture (38). Each of the electrodes has such a potential that an n-pole field or a combination of n-pole fields is generated, where n is an even integer from 4 through 16. A suitable choice of the n-pole field will make it possible to impart substantially any desired shape to the beam (6) and thus the focus on the target.

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Eindhoven, Netherlands

Arthur M Hoeberechts