Semiconductor wafer with a thin epitaxial silicon layer, and production process

• Main Authors: BLIETZ MARKUS, SCHAUER REINHARD, SCHMOLKE RUDIGER, VON AMMON WILFRIED
• Format: Patent
• Language: English
• Published: 29.07.2004
• Edition: 7
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; BASIC ELECTRIC ELEMENTS; CHEMISTRY; CRYSTAL GROWTH; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; METALLURGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SEMICONDUCTOR DEVICES; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

A semiconductor wafer is made of a silicon substrate wafer and an epitaxial silicon layer deposited thereon. The substrate wafer has a specific resistance of 0.1 to 50 Omegacm, an oxygen concentration of less than 7.5*10 atcm<-3 >and a nitrogen concentration of 1*10 to 5*10<15 atcm><-3>. The epitaxial layer is 0.2 to 1.0 mum thick and has a surface on which fewer than 30 LLS (localized light scattering) defects which are greater in size than 0.085 mum can be detected. A method for producing the semiconductor wafer has a sequence of steps for providing the substrate wafer with the aforementioned features; heating the substrate wafer in a deposition reactor to a deposition temperature of at least 1120° C.; and depositing the epitaxial layer thereon with a thickness of 0.2 to 1.0 mum, immediately after the deposition temperature has been reached.