MANUFACTURING METHOD OF EPITAXIAL SILICON WAFER

• Main Author: NINOMIYA MASAHARU
• Format: Patent
• Language: English
• Published: 13.04.2001
• 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

PROBLEM TO BE SOLVED: To provide a manufacturing method superior in IG capability which is complete in a relatively short period by suppressing uneven formation of oxygen precipitation nucleus of an epitaxial silicon wafer provided with the IG capacity, so that no BMD is formed near the surface of silicon wafer. SOLUTION: A potential nucleus is allowed to take place and grow over the entire crystal with a single-crystal silicon to which carbon is added by a CZ method in a low-temperature processing, and then the potential nucleus on the substrate surface is allowed to shrink and dissolve in a middle- temperature processing, while a BMD is grown and formed inside the substrate. Thus, the BMD appears inside the wafer, instead of explicitly appearing at the surface-layer part of it, allowing the variation in BMD density in a crystal growth method to be less under control. If an epitaxial film is formed on the substrate, the BMD is formed only inside the substrate with no surface defect.