HEAT TREATMENT OF SILICON WAFER

• Main Author: MATSUNO TOMOYUKI
• Format: Patent
• Language: English
• Published: 27.06.2000
• Edition: 7
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; CHEMISTRY; CRYSTAL GROWTH; METALLURGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; 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 heat treatment process which enables reduction in oxygen concentration in a wafer to a level required for forming a semiconductor device having excellent properties from the wafer. SOLUTION: This treatment process comprises: subjecting a silicon wafer to heat treatment in a hydrogen atmosphere at 1,100-1,200 deg.C; and subsequently, subjecting the heat-treated wafer to polishing treatment in such a way that a DZ(denuded zone) layer having a >=5 μm thickness remains in the wafer surface; wherein in the heat treatment stage, a silicon wafer having 11.0-13.0×1017 atms/cm3 interstitial oxygen concentration is subjected to heat treatment for a 10-30 min heat treatment time. By subjecting the wafer to hydrogen annealing treatment to reduce oxygen concentration in the wafer, the junction leak current in the region from the wafer surface layer to the depths of several μm can be reduced. By polishing the DZ layer, the asperity of the wafer surface and also the interface micro-roughness can be improved, to realize a silicon water capable of forming a semiconductor device having excellent operating speed characteristics and high insulation resistance.