Siltronic Ag

Wacker Siltronic Gesellschaft F&uuml;r Halbleiter Materialien Ag

Wacker Siltronic Gesellschaft Fur Halbeitermaterialien Mbh

Wolfgang Siebert

Peter Storck

Klaus Messmann

Wilfried Von Ammon

Reinhard Schauer

Guido Wenski

Gerhard Heier

Thomas Altmann

R&uuml;diger Schmolke

Dieter Gr&auml;f

Ruediger Schmolke

G&uuml;nther Obermeier

Erwin-Peter Mayer

Martin Fürfanger

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 cmwith a cross section of greater than or equal to 0.12 &#x3bc;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 &#x3bc;m&#xd7;1 &#x3bc;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. The process includes the following: (a) a stock removal polishing step as the only polishing step; (b) cleaning and drying of the semiconductor wafer; (c) pretreatment of the front surface of the semiconductor wafer at a temperature of from 950 to 1250 degrees Celsius in an epitaxy reactor; and (d) deposition of the epitaxial layer on the front surface of the pretreated semiconductor wafer.

Epitaxially coated semiconductor wafer and process for producing it

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 SFQRof less than or equal to 0.13 &#x3bc;m and a maximum density of 0.14 scattered light centers per cm. 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 &#x3bc;m&#xd7;1 &#x3bc;m reference area. Furthermore, there is a process for producing the semiconductor wafer. The process includes the following process steps: (a) as a single polishing step, simultaneous polishing of the front surface and of the back surface of the semiconductor wafer between rotating polishing plates while an alkaline polishing slurry is being supplied, the semiconductor wafer lying in a cutout of a carrier whose thickness is dimensioned to be 2 to 20 &#x3bc;m less than the thickness of the semiconductor wafer after the latter has been polished; (b) simultaneous treatment of the front surface and of the back surface of the semiconductor wafer between rotating polishing plates while a liquid containing at least one polyhydric alcohol having 2 to 6 carbon atoms is being supplied; (c) cleaning and drying of the semiconductor wafer; and (d) deposition of the epitaxial layer on the front surface of the semiconductor wafer produced in accordance with steps (a) to (c).

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 &#x2266;100 m&#x3a9;cm and a resistivity of the epitaxial layer of &#x3e;1 &#x3a9;cm without back-surface coating, the epitaxial layer of which semiconductor wafer has a resistance inhomogeneity of &#x3c;10%.

Process and apparatus for epitaxially coating a semiconductor wafer and epitaxially coated semiconductor wafer

Method for the production of an epitaxially grown semiconductor wafer

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.

Process for the production of an epitaxially coated semiconductor wafer

Growing community of inventors

Mehring, Germany

Wolfgang Siebert