Siltronic Ag

Atsushi Ikari

Wilfried Von Ammon

Katsuhiko Nakai

Martin Weber

Akiyoshi Tachikawa

Timo Mueller

Masamichi Ohkubo

Herbert Schmidt

Atsuki Matsumura

Kazunori Ishisaka

Hiroyuki Deai

Martin Grassl

Josef Brunner

Silicon wafers having excellent voltage resistance characteristics of an oxide film and high C-mode characteristics are derived from single crystal silicon ingots doped with nitrogen and hydrogen, characterized in that a plurality of voids constituting a bubble-like void aggregates are present &#x2267;50% relative to total voids; a Vregion having a void density of over 2&#xd7;10/cmand below 1&#xd7;10/cmis &#x2266;20% of the total area of wafer; a Vregion having a void density of 5&#xd7;10to 2&#xd7;10/cmoccupies &#x2267;80% of the total area of the wafer; and bulk microdefect density is &#x2267;5&#xd7;10/cm.

Silicon wafer and method for producing the same

The epitaxial layer defects generated from voids of a silicon substrate wafer containing added hydrogen are suppressed by a method for producing an epitaxial wafer by:

Epitaxial wafer and production method thereof

Hetero-semiconductor structures possessing an SOI structure containing a silicon-germanium mixed crystal are produced at a low cost and high productivity. The semiconductor substrates comprise a first layer formed of silicon having germanium added thereto, a second layer formed of an oxide and adjoined to the first layer, and a third layer derived from the same source as the first layer, but having an enriched content of germanium as a result of thermal oxidation and thinning of the third layer.

Semiconductor substrate and method for production thereof

The Czochralski method is used for producing p-doped and epitaxially coated semiconductor wafers from silicon, wherein a silicon single crystal is pulled, and during the pulling is doped with boron, hydrogen and nitrogen, and the single crystal thus obtained is processed to form p-doped semiconductor wafers which are epitaxially coated.

Process for producing p-doped and epitaxially coated semiconductor wafers from silicon

A silicon semiconductor substrate has a structure possessing oxygen precipitate defects fated to form gettering sites in a high density directly below the defect-free region of void type crystals. The silicon semiconductor substrate is formed by heat-treating a silicon semiconductor substrate derived from a silicon single crystal grown by the Czochralski method or the magnetic field-applied Czochralski method and characterized by satisfying the relational expression (Oi DZ)&#x2212;(COP DZ)&#x2266;10 &#x3bc;m wherein Oi DZ denotes a defect-free zone of oxygen precipitate crystal defects and COP DZ denotes a region devoid of a void type defect measuring not less than 0.11 &#x3bc;m in size, and having not less than 5&#xd7;10oxygen precipitate crystal defects per cm. The method for making the substrate comprises the steps of deriving a silicon semiconductor substrate from a silicon single crystal grown by the Czochralski method or the magnetic field-applied Czochralski method using molten silicon containing not less than 5&#xd7;10atoms and not more than 1.5&#xd7;10atoms of nitrogen per cmand heat-treating the silicon semiconductor substrate in a non-oxidizing atmosphere at a highest final temperature of not lower than 1150&#xb0; C. for not less than one hour.

Silicon semiconductor substrate and preparation thereof

A semiconductor substrate after heat-treatment in a non-oxidising atmosphere has the characteristics that the depth of the denuded zone may be greater than 12 &mgr;m or the defect-free depth of the void type defect is greater than 12 &mgr;m and the substrate has a locally densified portion produced by nitrogen segregation and exhibiting a signal strength two or more times the average signal strength at the depth of 12 &mgr;m or more below the surface thereof when measuring the concentration of nitrogen by using secondary ion mass-spectroscopy, and the density of the crystal defect of oxygen precipitates is 5&times;10 /cm or more, and the said substrate is produced by heat-treating for at least one hour at the temperature of 1200&deg; C. or more in a non-oxidising atmosphere.

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Yamaguchi, Japan

Atsushi Ikari