Siltronic Ag

Dirk Dantz

Reinhold Wahlich

Andreas Huber

Brian Murphy

Ulrich Lambert

Robert Hölzl

A process for producing a semiconductor substrate comprising a carrier wafer and a layer of single-crystalline semiconductor material: a) producing a layer containing recesses at the surface of a donor wafer of single-crystalline semiconductor material, b) joining the surface of the donor wafer containing recesses to the carrier wafer, c) heat treating to close the recesses at the interface between the carrier wafer and the donor wafer to form a layer of cavities within the donor wafer, and d) splitting the donor wafer along the layer of cavities, resulting in a layer of semiconductor material on the carrier wafer. Semiconductor substrates prepared thusly may have a single-crystalline semiconductor layer having a thickness of 100 nm or less, a layer thickness uniformity of 5% or less, and an HF defect density of 0.02/cmor less.

Semiconductor substrate and process for producing it

A process for producing a semiconductor substrate comprising a carrier wafer and a layer of single-crystalline semiconductor material:

A semiconductor substrate useful as a donor wafer is a single-crystal silicon wafer having a relaxed, single-crystal layer containing silicon and germanium on its surface, the germanium content at the surface of the layer being in the range from 10% by weight to 100% by weight, and a layer of periodically arranged cavities below the surface. The invention also relates to a process for producing this semiconductor substrate and to an sSOI wafer produced from this semiconductor substrate.

An SOI wafer, includes a substrate made from silicon, an electrically insulating layer with a thermal conductivity of at least 1.6 W/(Km) and a single-crystal silicon layer with a thickness of from 10 nm to 10 &#x3bc;m, a standard deviation of at most 5% from the mean layer thickness and a density of at most 0.5 HF defects/cm. A process is for producing an SOI wafer of this type, in which a substrate wafer made from silicon is joined to a donor wafer via a layer of the electrically insulating material which has previously been applied. The donor wafer bears a donor layer of single-crystal silicon, with a concentration of vacancies of at most 10/cmand of vacancy agglomerates of at most 10/cm. After the wafers have been joined, the thickness of the donor wafer is reduced in such a manner that the single-crystal silicon layer having these properties is formed from the donor layer, this single-crystal silicon layer being joined to the substrate wafer via the layer of electrically insulating material.

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Koenigslutter am Elm, Germany

Dirk Dantz