Welsh & Katz, Ltd.
Production method for silicon single crystal and production device for single crystal ingot, and heat treating method for silicon crystal wafer
A method for growing a silicon crystal by a Czochralsky method, wherein, let a pulling speed be V (mm/min) and an average value of an in-crystal temperature gradient in a pulling axis direction within a temperature range, a silicon melting point to 1350° C., be G (° C./mm), V/G ranges from 0.16 to 0.18 mm2/° C. min between a crystal center position and a crystal outer periphery position, and a ratio G outer/G center of an average value G of an in-crystal temperature gradient in a pulling axis direction within a temperature range, a silicon melting point to 1350° C., at a crystal outer surface to that at a crystal center is set to up to 1.10 to thereby obtain a high-quality perfect crystal silicon wafer. Such a perfect crystal silicon wafer, wherein an oxygen concentration is controlled to up to 13×1017 atoms/cm3, an initial heat treatment temperature is at least up to 500° C. and a temperature is raised at up to 1° C./min at least within 700 to 900° C., thereby making uniform a wafer radial distribution to an arbitrary oxygen precipitation density level.
Komatsu Denshi Kinzoku Kabushiki Kaisha
C C C C
C30B C30B C30B C30B
inventional inventional inventional inventional
Shinya Kozo Masashi Yoshiyuki Hirotaka Toshiaki Toshirou
Sadohara Nakamura Nishimura Shimanuki Nakajima Saishoji Kotooka