Siemens Aktiengesellschaft

Infineon Technologies Ag

Siemens Katiengesellschaft

Wolfgang Keller

Konrad Reuschel

Arno Kersting

Volker Lehmann

Hans-Peter Schabert

Hans Stut

Manfred Schnoeller

Hans-Christian Grassmann

Eberhard Spenke

Johann Ropers

Herbert Kramer

Gerhard Barowski

Gerhard Schrotter

Karl Schmidt

Joachim Kruger

Gerhard Schroetter

Alfred Muehlbauer

Reimer Emeis

A semiconductor diode has two electrodes that form a cathode and an anode. The semiconductor diode is distinguished by the fact that at least one of the electrodes is curved, and that a surface area of the other electrode amounts to at most 20% of a product of a width of the other electrode and an inner edge length of the curved electrode. An electrical circuit constructed in such a way that it contains the semiconductor diode is also disclosed. The semiconductor diode contains two electrodes which form the cathode and anode, and is distinguished by the fact that at least one of the electrodes is curved, and that the surface area of the other electrode amounts to at most 20% of the product of the width of the other electrode and the inner edge length of the curved electrode.

Semiconductor diode

A scattered-ray grid has a carrier with absorption elements arranged thereon in spaced rows which proceed essentially spoke-like relative to a grid center. Except for one or more rows which originate at the grid center, the individual rows of the scattered-ray grid, or of substantially identical grid sectors of the scattered-ray grid each originate from respectively different radii. The origin of each row is situated in an angle section, which is determined on the basis of at least two points lying on a circle, or an arc of circle, with a predetermined radius and which is divided in a predefined ratio for determining the position of the origin. The predetermined radius is incremented in a stepwise manner to define respective origins for all of the rows.

Scattered-ray grid, particularly for a medical X-ray device, and a method of determining the position of the absorption elements of a scattered-ray grid

For floating zone drawing of semiconductor rods having diameters greater than 100 mm, at the beginning of the zone drawing process, in particular during melting on of the seed crystal to the semiconductor rod to be drawn, a high load change and impedance change occurs. The power from the high-frequency (HF) generator is no longer coupled thereto optimally. Heating up the feed line to the induction heating coil is the result. This heating is avoided by connecting the HF generator via a feed line to a tank circuit device. A variable tank circuit capacitor connected in parallel and to the series oscillator circuit coil feeding one side of a parallel circuit of a heating circuit capacitor and the induction heating coil. The variable oscillator circuit capacitor is adjusted as a function of the voltage drop across the induction heating coil.

Floating zone drawing circuitry for semiconductor rods

When semiconductor rods during floating zone melting are doped with dopants having a very low distribution coefficient, the non-homogeneous temperature distribution causes a relatively strong non-homogeneous separation of the dopants (striation). The homogeneity can be improved through an after-heater (6) connected to the heating coil (4) and arranged on the side of the monocrystalline rod part (2), the heater being coaxial with the coil and connected parallel to it.

Induction heater for floating zone melting

Semiconductor rods are doped in a crucible-free, float-zone enclosure, by the introduction of dopant pellets into the float-zone. The dopant pellets are located in a hopper (7), mounted on the inside of the float-zone enclosure. The introduction of individual dopant pellets is controlled, through an actuating device (12), from the outside of the enclosure.

Apparatus for doping semiconductor rods with solid dopants

Apparatus for crucible-free zone melting an end-supported semiconductor rod, including an RF generator having a resonant circuit for determining the generator frequency, the resonant circuit having connected therein a tank-circuit coil and a tank-circuit capacitor, and an induction heating coil fed by the RF generator and annularly surrounding the semiconductor rod, the tank-circuit coil being formed as a primary winding to the induction heating coil acting as a secondary winding, both the tank circuit coil and the induction heating coil forming a structural unit having a fixed magnetic coupling.

Apparatus for crucible-free floating-zone melting a semiconductor rod,

A pancake induction heating coil for crucible-free zone melting of semiconductor crystal rods, includes a primary winding surrounding a semiconductor rod to be remelted in the form of a ring through which cooling liquid flows, a secondary winding surrounding the primary winding and having a side facing the semiconductor rod, and an energy concentrator lying in the plane of the primary winding and having a circular opening formed substantially in the center thereof for the semiconductor rod, the side of the secondary winding facing the semiconductor rod being electrically conductingly connected to the energy concentrator.

Induction coil in the form of a pancake coil for crucible-free zone

Flat induction heating coil for crucible-free floating zone melting a semiconductor crystalline rod having a turn annularly surrounding the semiconductor rod, the turn being formed with at least one passage therethrough for a cooling liquid, including an energy concentrator located at an inner side of the heating coil turn facing towards the semiconductor rod to be melted, the energy concentrator being subdivided into a plurality of segments electrically isolated from one another.

Induction coil in the form of a flat coil for crucible-free floating

Method of setting a stable melting zone in a semiconductor crystalline rod during crucible-free zone melting thereof, by means of a single-winding induction heating coil having an inner diameter smaller than the diameter of a portion of the rod being fed to the melting zone which includes performing the crucible-free zone melting in an argon atmosphere at an overpressure in vicinity of at least 1.5 ata and maximally 6 ata, and setting the outer melting-zone height at a value of between 15 and 23 mm for a diameter of the recrystallized rod portion within a range of 30 to 50 mm, at a value of between 18 and 26 mm for a diameter of the recrystallized rod portion within a range of 50 to 75 mm and at a limiting value of 32 mm for a rod diameter greater than 75 mm.

Method of setting a stable melting zone in a semiconductor crystalline

Method of producing silicon by crucible-free zone melting a substantially vertically held silicon rod with which a melting zone, produced by an induction heating coil which, together with an oscillating-circuit coil connected in series therewith and determining the oscillating-circuit frequency and having a high inductance in comparison with that of the induction heating coil heating up the rod material, forms the inductive component of a heating parallel oscillating circuit fed by a high-frequency generator and has a heating circuit capacitor connected in parallel with the heating coil, is passed through the silicon rod in direction of the rod axis, which comprises dimensioning the component resonance circuit formed by the induction heating coil and the heating-circuit capacitor to a frequency deviating by less than a factor of 2 from the frequency of the high-frequency generator.

Method and apparatus for the manufacture of silicon by crucible-free

Current lead-in of the coaxial type, including at least two conducting tubes passing through a container wall, a gas-tight seal disposed between the tubes and the walls, an induction heating coil supplied with high frequency current from the tubes for producing a melting zone in a semiconductor rod, and a pressure-deformable electrically-insulating tension element disposed between the tubes. The tubes are in the form of an inner end and an outer tube. A pressure plate and a ring are disposed near one end of the inner tube, a ceramic tube surrounds the inner tube between the ring and the tension elements, and a ceramic ring stop is disposed at the other end of the inner tube. The ceramic tube and tension element have smaller outside diameters than the ring and stop and they are surrounded by the outer tube. Pressure is applied to the tension element by screws in the pressure plate or by a nut screwed onto the inner tube.

Current lead-in of the coaxial type for sealing to a container wall

Method of producing current lead-ins having a coaxial construction which includes applying to the outer surface of a first conductor tube of given outer diameter a layer of resilient vulcanized silicone rubber having an outwardly flaring conical sealing portion at one end of the tube and pressing the first conductor tube and a second conductor tube having an inner diameter greater than the outer diameter of the first conductor tube and formed with an outwardly flaring conical end portion into one another so as to form a seal and stop against the outside at the conical portions thereof.

Method of producing current lead-ins having coaxial construction

A process for producing phosphorous-doped silicon monocrystals having a select peripheral depletion or enrichment of dopant atoms along the radial direction of such monocrystals comprises providing a silicon monocrystalline rod homogeneously doped with phosphorous, as by neutron doping, and subjecting such homogeneously doped monocrystalline rod to a peripheral zone melt cycle in a select atmosphere such that the peripheral melt zone depth within the monocrystalline rod is controlled so as to be less than the radius of the rod in accordance with the desired peripheral dopant concentration in the ultimately attained rod.

Process for producing phosophorous-doped silicon monocrystals having a

Molten silicon is controllably fed into a nip between spaced-apart rollers, converted into a wide ribbon of a desired thickness by passing through such nip and then solidified. The solidified silicon ribbon is then severed into plate-shaped bodies of desired dimension for use in the manufacture of solar cells.

Process for producing plate-shaped silicon bodies for solar cells

Stock semiconductor crystal rods are zone melt refined by positioning such stock rods in a zone melt environment with a seed crystal attached to a lower end thereof, generating a melt zone at the juncture of the seed crystal and stock rod and controllably moving the melt zone away from the juncture and through the stock rod to a select point thereon, uniformly supporting the cone-shaped lower portion of the rod being refined from below the juncture to an area adjacent the select point so as to prevent vibrations and the like within the rod being processed, applying a controlled electrical current across the melt zone from the ends of the rod being refined and controllably moving the melt zone from the select point through the remainder of the rod. The uniform support is provided by a movable electrically conductive funnel-shaped jacket filled with an electrically conductive stabilizing means, such as metal spheroids or particulate silicon particles, molten metal, etc. and the electrical leads are connected to such jacket and to an upper rod support member whereby electrical current is fed from one end of the rod to the other.

Growing community of inventors

Munich, Germany

Wolfgang Keller