Licentia Patent-verwaltungs Gmbh

Eupec Europaeische Gesellschaft Fuer Leistungshalbleiter Mbh & Co. Kg

Alois Sonntag

Wolfgang Pikorz

Karl H Sommer

Ludwig Herold

Max Schulz

Karlheinz Sommer

Adolf Goetzberger

Hans Scheuermann

Holger Schoof

Karl Rathmann

Edgar Borchert

Jurgen Brandt

The destruction-free rapid dismantling of current of power semiconductor components can be substantially enhanced when the inhibiting pn-junction is produced with a polished surface of the semiconductor body. The pn-junction thus becomes so uniform that local overloads are avoided. As a result, the speed of the dismantling of the current of the power semiconductor can be increased.

Method for manufacturing a power semiconductor component for high speed

An asymmetrical thyristor having an n.sup.+ pn.sup.- np.sup.- zone sequence whose functionability is not impaired and, in particular, whose reverse blocking characteristic is not degraded, if it fires after a forward current load and subsequent commutation before its turn-off time has expired due to the positive voltage increasing again. This insensitivity to refiring after commutation when falling below the turn-off time is realized by a flat rise of the doping concentration from the n.sup.- -type zone to the n-type zone, with the doping concentration in the n-type layer increasing approximately exponentially over a path of at least 50.mu.. In order to keep the forward off-state current low with a flat nn.sup.- junction, the thickness and doping of the n.sup.- -type layer are dimensioned such that at the highest intended forward off-state voltage the electric field intensity at the pn.sup.- junction is about 1.5.multidot.10.sup.5 V/cm, drops approximately linearly in the n.sup.- -type layer and, at the nn.sup.- junction, has approximately 1/4 of the value it has at the pn.sup.- junction. Methods for producing such a thyristor are also disclosed.

Asymmetrical thyristor and method for producing same

A thyristor with an amplifying gate including a silicon semiconductor body having n.sup.+ conductive main and auxiliary emitters at the cathode side, wherein a p.sup.+ zone is formed in a region of the p control base zone adjacent the surface of the semiconductor body between the auxiliary emitter zone and the main emitter zone. The p.sup.+ zone contacts the edge region of the main emitter zone which faces the auxiliary emitter zone, and preferably projects into the edge region, and forms a p.sup.+ n.sup.+ junction with the main emitter zone. Also, the p.sup.+ zone is laterally spaced from and does not contact the n.sup.+ auxiliary emitter zone.

Thyristor having n.sup.+ - main and auxiliary emitters and a p.sup.+

A molybdenum disc suitable for the use as a semiconductor. The disc has a thickness of about 0.5 to several mm and is coated with a noble metal that is applied to the molybdenum in a layer thickness of 0.02.mu. via an intermediate layer of chromium having a layer thickness of 0.5 to 10.0.mu..

Molybdenum coated with a noble metal

A fast switching thyristor having a shorted emitter structure in which, in order to shorten the turn-off time, the charge carrier lifetime is set to be low by means of recombination centers. The charge carrier lifetime in at least the control base zone of the thyristor is set initially to be homogeneous and low corresponding to a desired firing resistance underneath the emitter zone with respect to the voltage rise of the returning forward voltage in the thyristor after every recovery process, and the charge carrier lifetime is set to be low compared to the homogeneous setting in the partial region of the control base zone extending from below the control electrode substantially to the portion of the edge of the emitter zone which faces the control electrode but without contacting the edge of the emitter zone. If the thyristor is of the amplifying gate type having a shorted auxiliary emitter structure, then the charge carrier lifetime in the region between the main and auxiliary emitter zones is less than the charge carrier lifetime in the region between the auxiliary emitter zone and control electrode which in turn is less than the homogeneously set charge carrier lifetime in the bulk or volume of the device. Additionally, the density of the shorting channels in the edge region of the auxiliary emitter zone facing the control electrode is greater than in the remainder of this zone and than in the main emitter zone.

Thyristor element with short turn-off time and method for producing such

A high performance, wafer-shaped semiconductor device of the type including a wafer-shaped semiconductor element, a pair of electrodes located on the surfaces of the element, a pair of cylindrical metal bodies contacting the electrodes, an insulating ring enclosing and centering the metal bodies and the semiconductor element and a plastic jacket surrounding the insulating ring for tightly encasing the semiconductor device. In addition, there is provided a pair of annular sheet metal strips each of which has an inner edge region fastened to one of the cylindrical metal bodies and a corrugated chemically roughened outer edge region which is embedded in the plastic jacket. A powder coating is applied to the chemically roughened outer edge region for the purpose of providing a pressure and oil-tight housing for the semiconductor device.

Semiconductor device plastic jacket having first and second annular

An improved thyristor with pressure contacting in which at least a portion of the control base zone in addition to the cathode zone extends on a single major surface of a wafer-shaped thyristor semiconductor body and the cathode base zone and the control base zone are each contiguous and are provided at least in part at the major surface with completely insulated ohmic electrodes, i.e., cathode and control electrodes. The ohmic cathode and control electrodes are insulated from one another by means of a layer of insulating material which covers those portions of the major surface of the semiconductor body which are not provided with electrodes and the control electrode except for the connecting contact for the control electrode, the planar surface of the layer of insulating material not having to lie at the level of the cathode electrode surface, and the cathode electrode is pressure contacted by means of a contacting wafer which is covered, at least on the surface thereof contacting the cathode electrode, with a highly conductive ductile material and is provided with a recess for the connecting terminal of the control electrode.

Thyristor with pressure contacting

A high output semiconductor device of the type which is tightly encased in a plastic coating, and includes a wafer-shaped semiconductor body having electrodes at its opposed major surfaces, two cylindrical metal bodies serving as current connecting and heat dissipating members contacting the electrodes of the semiconductor body at the respective major surfaces, and an insulating ring which encloses the metal bodies and the semiconductor body thereby centering the same. A pair of annular sheet metal strips, each having a dished portion adjacent the inner periphery, are each fastened at their inner peripheries to the superficies of a respective one of the two metal bodies. The dished portion of each of the annular strips encloses one frontal face or edge surface of the insulating ring while leaving an air gap therebetween and the outer edge portion of each annular strip extends into and is rigidly embedded in the plastic coating which has been produced by encasing or spraying under pressure around the outer surface of the insulating ring. The insulating ring is made of a material which does not adhere to the metal bodies or the annular strips and has a high softening temperature.

High output wafer-shaped semiconductor component with plastic coating

A method of setting the lifetime of charge carriers in a semiconductor body by the formation of recombination centers in the semiconductor body. The quantity of the recombination centers forming material necessary to provide the desired concentration in the semiconductor body is applied to the surface of the semiconductor body and into the surface thereof by ion implantation, and thereafter, in order to diffuse the material into the semiconductor body, the body is heated until an approximately stationary value for the charge carrier lifetime has developed in the entire volume of the body.

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Warstein, Germany

Alois Sonntag