Silicon semiconductor substrate and preparation thereof

摘要

Task: To provide a silicon semiconductor substrate of 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 and a method for the production thereof. Means to fulfil the Task: A silicon semiconductor substrate 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 characterised by satisfying the relational expression (Oi DZ) - (COP DZ)≤10 mu 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 mu m in size, and having not less than 5 x 10<8> oxygen precipitate crystal defects per cm<3> and a method for the production thereof, comprising 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 x 10<17> atoms and not more than 1.5 x 10<19> atoms of nitrogen per cm<3> and heat-treating the silicon semiconductor substrate in a non-oxidising atmosphere at a highest final temperature of not lower than 1150 DEG C for not less than one hour.