Freiberger Compound Materials Gmbh

André Kleinwechter

Stefan Eichler

Berndt Weinert

Ralf Hammer

Max Scheffer-Czygan

Christoph Klement

Ralf Gruszynsky

Christa Willnauer

Wolfram Fliegel

Michael Mäder

Tilo Flade

Sylvia Müller

Cornelia Kumann

A gallium arsenide substrate which exhibits at least one surface having a surface oxide layer comprising gallium and arsenic oxides and which exhibits at least one surface having, according to an ellipsometric lateral substrate mapping with an optical surface analyzer, based on a substrate diameter of 150 mm as reference, a defect number of <6000 and/or a total defect area of less than 2 cm, wherein a defect is defined as a continuous area of greater than 1000 μmhaving a deviation from the average measurement signal in elipsometric lateral substrate mapping with an optical surface analyzer of at least ±0.05%.

Gallium arsenide substrate comprising a surface oxide layer with improved surface homogeneity

The present invention relates to a novel provided gallium arsenide substrates as well as the use thereof. The gallium arsenide substrates provided according to the invention exhibit a so far not obtained surface quality, in particular a homogeneity of surface properties, which is detectable by means of optical surface analyzers, by way of example by means of ellipsometric lateral substrate mapping for optical contact-free quantitative characterization.

The present invention relates to a novel process for producing a surface-treated gallium arsenide substrate as well as novel provided gallium arsenide substrates as such as well as the use thereof. The improvement of the process according to the invention is based on a particular final surface treatment with an oxidation treatment of at least one surface of the gallium arsenide substrate in dry condition by means of UV radiation and/or ozone gas, a contacting of the at least one surface of the gallium arsenide substrate with at least one liquid medium and a Marangoni drying of the gallium arsenide substrate. The gallium arsenide substrates provided according to the invention exhibit a so far not obtained surface quality, in particular a homogeneity of surface properties, which is detectable by means of optical surface analyzers, specifically by means of ellipsometric lateral substrate mapping for the optical contact-free quantitative characterization.

Process for producing a gallium arsenide substrate which includes marangoni drying

A wire saw () for cutting a workpiece includes a device () for setting, controlling and/or maintaining a predetermined or desired water content in at least part of the gaseous medium that contacts the slurry. With the wire saw according to the invention and the process carried out using this wire saw, it is possible to achieve consistently good surface properties of the resulting wafers over a prolonged period of use of a slurry.

Process, apparatus and slurry for wire sawing

A method for the division of single crystals, in particular of GaAs, is provided in which a single crystal () to be cut into at least two parts and a cutting tool () are moved relative to one another in a direction of advancement (V) and wherein the single crystal () is oriented in such a way that a specified crystallographic orientation (K) lies in the cutting plane (T), characterized in that an angle (&#x3c1;) between the specified crystallographic direction (K) and the direction of advancement (V) is chosen in such a way that forces which act on the cutting tool during cutting in a direction at right angles to the cutting plane compensate one another.

Method and device for cutting single crystals, in addition to an adjusting device and a test method for determining a crystal orientation

An apparatus and a method for determining the orientation of a crystallographic plane (100) relative to a crystal surface () are provided, in which the orientation is free from errors of adhesion of the crystal or contamination of the holders for the crystal. For this purpose, the angle which the crystal surface to be measured forms with a reference axis and the angle which the crystallographic plane forms with the reference axis are measured and subtracted. In a wire sawing apparatus with an X-Y positioning unit, next the desired correction is made with the aid of measurement of the orientation and at the same time the crystal is displaced in horizontal and vertical positions. As a result, there remains a further degree of freedom of rotation of the crystal in the cutting plane for achieving a cut which is free from forces perpendicular to the feed direction and wire direction, so that no tool deflection takes place or the cutting forces are minimal. Further, the precision of orientation is increased.

Device and method for determining the orientation of a crystallographic plane in relation to a crystal surface and device for cutting a single crystal in a cutting machine

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Freiberg, Germany

André Kleinwechter