U.S. Philips Corporation

Cambridge Display Technology Limited

Koninklijke Philips Corporation N.v.

U.S. Phillips Corporation

Adam R Brown

Richard Henry Friend

Dagobert Michel De Leeuw

Andrew Bruce Holmes

Paul Leslie Burn

Godefridus A M Hurkx

Donal D Bradley

Arno Kraft

Wiebe B De Boer

Edsko E Havinga

Wolter Ten Hoeve

Hans Wijnberg

Neil Clement Greenham

Anita Pomp

Jeremy H Burroughes

Raymond J E Hueting

Knut H Chmii

Jan Willem Slotboom

Jan W Slotboom

Stephen Carl Moratti

Franco Cacialli

Hendrik G A Huizing

Josef Herbert Martens

Stephen W Hodgskiss

Mark Gajda

Holger Schligtenhorst

Knut H Chmil

Johannes Gruener

Michael S Peter

Erik J Lous

A semiconductor device with a tunnel diode comprises two mutually adjoining semiconductor regions ( ) of opposed conductivity types having high enough doping concentrations to provide a tunneling junction. Portions ( A, A) of the semiconductor regions adjoining the junction comprise a mixed crystal of silicon and germanium. The doping concentration of both phosphorus and boron are substantially increased, given the same amount of dopants being offered as during the formation of the remainder of the regions. The tunneling efficiency is substantially improved, and also because of the reduced bandgap of said portions ( A, A). A much steeper current-voltage characteristic both in the forward and in the reverse direction is achieved. Thus, the tunneling pn junction can be used as a transition between two conventional diodes which are stacked one on the other and formed in a single epitaxial growing process. The doping concentration may be 6&times;10 or even more than 10 at/cm . A simple method of manufacturing such a device is preferably done at a temperature between 550&deg; C. and 800&deg; C.

Method of manufacturing semiconductor device with a tunnel diode

The invention relates to a semiconductor device having a rectifying junction ( ) which is situated between two (semiconductor) regions ( ) of an opposite conductivity type. The second region ( ), which includes silicon, is thicker and has a smaller doping concentration than the first region ( ) which includes a sub-region comprising a mixed crystal of silicon and germanium. The two regions ( ) are each provided with a connection conductor ( ). Such a device can very suitably be used as a switching element, in particular as a switching element for a high voltage and/or high power. In the known device, the silicon-germanium mixed crystal is relaxed, leading to the formation of misfit dislocations. These serve to reduce the service life of the minority charge carriers, thus enabling the device to be switched very rapidly. In a device in accordance with the invention, the entire first region ( ) comprises a mixed crystal of silicon and germanium, and the germanium content and the thickness of the first region ( ) are selected so that the voltage built up in the semiconductor device remains below the level at which misfit dislocations develop. Surprisingly, it has been found that such a device can also be switched very rapidly, even more rapidly than the known device. The absence of misfit dislocations has an additional advantage, namely that the device is very reliable. Misfit dislocations do not develop if the product of said relative deviation in the lattice constant and the thickness of the first region is smaller than or equal to 40 nm %. A safe upper limit for said product is 30 nm %.

Semiconductor device having a rectifying junction and method of manufacturing same

A semiconductor body (,) is provided having a first semiconductor region (,) of one conductivity type separated from a first major surface (,) by a second semiconductor region (,) of the opposite conductivity type. A trench (,) is etched through the second semiconductor region (,) to an etch stop layer (,) provided in the region of the pn junction between the first (,) and second (,) regions, by using an etching process which enables the etching process to be stopped at the etch stop layer. A gate (,) is provided within the trench (,). A source (,) separated from the first region (,) by the second region (,) is formed adjacent the trench so that a conduction channel area (,) of the second region (,) adjacent the trench provides a conduction path between the source and first regions which is controllable by the gate.

Method of manufacturing a trench gate field effect semiconductor device

A trench gate field effect device has a semiconductor body (,) with a trench (,) extending into a first major surface (,) so as to define a regular array of polygonal source cells (,). Each source cell contains a source region (,) and a body region (,) with the body regions separating the source regions from a common further region (,). A gate (G) extends within and along said trench (,) for controlling a conduction channel through each of the body regions. Each source cell (,) has a central semiconductor region (,) which is more highly doped than said body regions, is of opposite conductivity type to the further region and forms a diode with the further region. Each source cell (,) has an inner trench boundary (,) and an outer polygonal trench boundary (,) with the inner trench boundary bounding a central subsidiary cell (,) containing the central semiconductor region (,). A plurality of trench portions (,) radiate outwardly from the inner trench boundary (,) to the outer trench boundary (,) The trench portions separate the area between the inner and outer trench boundaries into a plurality of segments each having one side longer than another. Each segment forms a subsidiary source cell (,).

Electronic device comprising a trench gate field effect device

A semiconductor device with a tunnel diode (,) is particularly suitable for various applications. Such a device comprises two mutually adjoining semiconductor regions (,) of opposed conductivity types and having doping concentrations which are so high that breakdown between them leads to conduction by means of tunnelling. A disadvantage of the known device is that the current-voltage characteristic is not yet steep enough for some applications. In a device according to the invention, the portions (,A,,A) of the semiconductor regions (,) adjoining the junction (,) comprise a mixed crystal of silicon and germanium. It is surprisingly found that the doping concentration of both phosphorus and boron are substantially increased, given the same amount of dopants being offered as during the formation of the remainder of the regions (,). The tunnelling efficiency is substantially improved as a result of this, and also because of the reduced bandgap of said portions (,A,,A), and the device according to the invention has a much steeper current-voltage characteristic both in the forward and in the reverse direction. This opens perspectives for inter alia an attractive application where the tunnelling pn junction (,) is used as a transition between two conventional diodes, for example pn or pin diodes, which are used one stacked on the other and which can be formed in a single epitaxial growing process thanks to the invention. The portions (,A,,A) adjoining the tunnelling junction (,) are preferably 5 to 30 nm thick and comprise between 10 and 50 at % germanium. The doping concentration may be 6&times;10,or even more than 10,at/cm,. The invention further relates to a simple method of manufacturing a device according to the invention. This is preferably done at a temperature of between 550&deg; C. and 800&deg; C.

Semiconductor device with a tunnel diode and method of manufacturing same

Devices with Schottky junctions are manufactured in that a semiconductor body with a substrate is provided with a first, for example n-type semiconductor region in the form of an epitaxial layer. A Schottky metal is locally provided thereon. A second semiconductor region is advantageously formed directly below the Schottky metal, with the purpose of adjusting the level of the Schottky barrier. Around this, a third semiconductor region is formed in the first region at at least two sides, which third region is then of the p-conductivity type and, when it entirely surrounds the second region, forms a so-called guard ring. A disadvantage of the above known method is that the devices obtained thereby have a (forward) current-voltage characteristic which is not very well controllable and reproducible. This hampers mass manufacture. To counteract this disadvantage, a method according to the invention provides the formation of the second semiconductor region by means of low-temperature gas phase epitaxy, such that it has the first or the second conductivity type, and the third region is formed by means of ion implantation, the second semiconductor region being formed after the third region has been formed. Devices are obtained thereby whose current-voltage characteristics can be adjusted over a wide range with very good reproducibility and well controlled. The second semiconductor region may be provided over the entire surface or selectively within the third region only.

Method of manufacturing a semiconductor device with a schottky junction

The invention relates to a method of preparing thiophene-containing or furan-containing conjugated compounds such as polythiophene. The method uses a precursor compound having tetrahydrothiophene or tetrahydrofuran precursor units having arylthio or alkylthio substituents. The precursor units can be thermally converted into thiophene or furan units. Due to the presence of the precursor units the precursor compound is soluble and can, unlike the corresponding conjugated compound, be processed from solution.

Method of preparing a thiophene-containing or furan-containing conjugated compound and precursor compound and use thereof for making semiconductor device

Method of preparing a thiophene-containing or furan-containing

Electroluminescent devices

Manufacture of electroluminescent devices

Electroluminescent device comprising a chromophoric polymeric composition

A semiconductor device is provided with an organic material which is formed by a solid-state mixture of organic donor and organic acceptor molecules. A semiconducting solid-state mixture is known with molar ratios between donor and acceptor molecules of 1.3:2 and 1.66:2. The known solid-state mixture has the disadvantage that its electrical conductivity is comparatively high, so that it is not possible to manufacture switchable devices from the mixture. Here the material includes an n- or p-type semiconductor material, the n-type semiconductor material having a molar ratio between the donor and acceptor molecules below 0.05, and the p-type semiconductor material having this ratio above 20. These solid-state mixtures may be used for manufacturing switchable semiconductor devices. The n- and p-type organic solid-state mixtures can be used for manufacturing transistors, diodes, and field effect transistors in a same manner as, for example, doped silicon or germanium.

Semiconductor device having an organic semiconductor material

A method is provided for forming in a semiconductive conjugated polymer at least first and second legions having different optical properties. The method comprises: forming a layer of a precursor polymer and permitting the first region to come into contact with a reactant, such as an acid, and heat while permitting the second region to come into contact with a lower concentration of the reactant. The reactant affects the conversion conditions of the precursor polymer in such a way as to control the optical properties of at least the first region so that the optical properties of the first region are different from those of the second region. The precursor polymer may comprise a poly(arylene-1, 2-ethanediyl) polymer, at least some of the ethane groups of which include a modifier group whose susceptibility to elimination is increased in the presence of the reactant.

Optical device incorporating semiconductive conjugated polymer

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Eindhoven, Netherlands

Adam R Brown