Silicon wafer and production method thereof

• Main Authors: HIROYUKI DEAI, TAKAYAMA
• Format: Patent
• Language: Chinese; English
• Published: 14.03.2012
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

To provide a silicon wafer comprising: a silicon substrate; a first epitaxial layer laid on one side of the silicon wafer, wherein the absolute value of the difference between the donor concentration and the acceptor concentration is set to equal or more than 110 18 atoms/cm 3 ; and a second epitaxial layer laid on the first epitaxial layer, whose conductivity type is the same as for said first epitaxial layer, wherein the absolute value of the difference between the donor concentration and the acceptor concentration is set to equal or less than 510 17 atoms/cm 3 ; wherein, by doping a lattice constant adjusting material into the first epitaxial layer, the variation amount ((a 1 - a Si )/ a Si ) of the lattice constant of the first epitaxial layer (a 1 ) relative to the lattice constant of the silicon single crystal (a Si ) as well as the variation amount ((a 2 - a Si ) / a Si ) of the lattice constant of the second epitaxial layer (a 2 ) relative to the lattice constant of the silicon single crystal (a si )