Abstract: A semiconductor wafer with a front surface and a back surface and an epitaxial layer of semiconducting material deposited on the front surface, wherein the surface of the epitaxial layer has a maximum density of 0.14 localized light scatterers per cm2 with a cross section of greater than or equal to 0.12 ?m, and the front surface of the semiconductor wafer, prior to the deposition of the epitaxial layer, has a surface roughness of 0.05 to 0.29 nm RMS, measured by AFM on a 1 ?m×1 ?m reference area. There is also a process for producing a semiconductor wafer with a front surface and a back surface and an epitaxial layer of semiconducting material deposited on the front surface.

Abstract: A semiconductor wafer with a front surface and a back surface and an epitaxial layer of semiconducting material deposited on the front surface. In the semiconductor wafer, the epitaxial layer has a maximum local flatness value SFQRmax of less than or equal to 0.13 ?m and a maximum density of 0.14 scattered light centers per cm2. The front surface of the semiconductor wafer, prior to the deposition of the epitaxial layer, has a surface roughness of 0.05 to 0.29 nm RMS, measured by AFM on a 1 ?m×1 ?m reference area. Furthermore, there is a process for producing the semiconductor wafer.

Abstract: A process for epitaxially coating the front surface of a semiconductor wafer in a CVD reactor, the front surface of the semiconductor wafer being exposed to a process gas which contains a source gas and a carrier gas, and the back surface of the semiconductor wafer being exposed to a displacement gas, wherein the displacement gas contains no more than 5% by volume of hydrogen, with the result that diffusion of dopants out of the back surface of the semiconductor wafer, which is intensified by hydrogen, is substantially avoided. With this process, it is possible to produce a semiconductor wafer with a substrate resistivity of ?100 m?cm and a resistivity of the epitaxial layer of >1 ?cm without back-surface coating, the epitaxial layer of which semiconductor wafer has a resistance inhomogeneity of <10%.

Abstract: A process for epitaxially coating the front surface of a semiconductor wafer in a CVD reactor, the front surface of the semiconductor wafer being exposed to a process gas which contains a source gas and a carrier gas, and the back surface of the semiconductor wafer being exposed to a displacement gas, wherein the displacement gas contains no more than 5% by volume of hydrogen, with the result that diffusion of dopants out of the back surface of the semiconductor wafer, which is intensified by hydrogen, is substantially avoided. With this process, it is possible to produce a semiconductor wafer with a substrate resistivity of ?100 m?cm and a resistivity of the epitaxial layer of >1 ?cm without back-surface coating, the epitaxial layer of which semiconductor wafer has a resistance inhomogeneity of <10%.

Abstract: A semiconductor wafer with a front surface and a back surface and an epitaxial layer of semiconducting material deposited on the front surface, wherein the surface of the epitaxial layer has a maximum density of 0.14 localized light scatterers per cm2 with a cross section of greater than or equal to 0.12 &mgr;m, and the front surface of the semiconductor wafer, prior to the deposition of the epitaxial layer, has a surface roughness of 0.05 to 0.29 nm RMS, measured by AFM on a 1 &mgr;m×1 &mgr;m reference area. There is also a process for producing a semiconductor wafer with a front surface and a back surface and an epitaxial layer of semiconducting material deposited on the front surface.

Abstract: A process for epitaxially coating the front surface of a semiconductor wafer in a CVD reactor, the front surface of the semiconductor wafer being exposed to a process gas which contains a source gas and a carrier gas, and the back surface of the semiconductor wafer being exposed to a displacement gas, wherein the displacement gas contains no more than 5% by volume of hydrogen, with the result that diffusion of dopants out of the back surface of the semiconductor wafer, which is intensified by hydrogen, is substantially avoided. With this process, it is possible to produce a semiconductor wafer with a substrate resistivity of ≦100 m&OHgr;cm and a resistivity of the epitaxial layer of >1 &OHgr;cm without back-surface coating, the epitaxial layer of which semiconductor wafer has a resistance inhomogeneity of <10%.

Abstract: A method for the production of a semiconductor wafer having a front and a back and an epitaxial layer of semiconductor material deposited on the front, includes the following process steps: (a) preparing a substrate wafer having a polished front and a specific thickness; (b) pretreating the front of the substrate wafer in the presence of HCl gas and a silane source at a temperature of from 950 to 1250 degrees Celsius in an epitaxy reactor, the thickness of the substrate wafer remaining substantially unchanged; and (c) depositing the epitaxial layer on the front of the pretreated substrate wafer.

Abstract: A semiconductor wafer with a front surface and a back surface and an epitaxial layer of semiconducting material deposited on the front surface. In the semiconductor wafer, the epitaxial layer has a maximum local flatness value SFQRmax of less than or equal to 0.13 &mgr;m and a maximum density of 0.14 scattered light centers per cm2. The front surface of the semiconductor wafer, prior to the deposition of the epitaxial layer, has a surface roughness of 0.05 to 0.29 nm RMS, measured by AFM on a 1 &mgr;m×1 &mgr;m reference area. Furthermore, there is a process for producing the semiconductor wafer.

Abstract: A method for the production of a semiconductor wafer having a front and a back and an epitaxial layer of semiconductor material deposited on the front, includes the following process steps:

Abstract: A process for the production of an epitaxially coated semiconductor wafer, composed of a substrate wafer of monocrystalline silicon having a front side and a rear side, has at least one layer of semiconductor material which is epitaxially deposited on the front side of the substrate wafer and which is obtained by production of a heavily doped silicon monocrystal by crucible-free zone pulling, production of a substrate wafer having polished front side from the monocrystal and deposition of at least one epitaxial layer of semiconductor material on the front side of the substrate wafer.

Abstract: A mixture will involve a risk of explosion if a concentration limit is exceeded. For this reason only part of the liquid is admixed to the gas in a first mixing zone so that the concentration limit above which there is a risk of explosion will not be exceeded. In a second mixing zone, the remaining quantity of liquid is added to the mixture withdrawn from the first mixing zone and the explosive concentration is exceeded. That mixture, in which the gas and liquid are distributed as homogeneously as possible, is reacted in a reaction zone. The reaction zone directly succeeds the second mixing zone.