Tokyo Shibaura Denki Kabushiki Kaisha

Jisaburo Ushizawa

Tsuguo Fukuda

Masayuki Watanabe

Syoichi Washizuka

Yoshihiro Kokubun

Takashi Fujii

The invention provides a method and an apparatus for manufacturing single crystals wherein the weight of the single crystal pulled is measured by a weight detector. The measured weight is compared with a reference weight signal which is generated from a reference weight signal generator. A weight deviation signal representing a difference between these two signals is generated by a weight deviation detector. The weight deviation signal is differentiated by a first differentiation circuit and a differentiation output signal obtained is corrected for compensation for the buoyancy of the liquid encapsulant by a signal which is generated by a buoyancy correction signal generator. A corrected signal thus obtained is differentiated by a second differentiation circuit and is thereafter added to the corrected signal. The addition result is phase-compensated by a phase-compensating circuit. The phase-compensated signal is supplied to a heating control circuit. At the same time, the heating control circuit generates a heating control signal to a heating device in response to a program signal which is generated from a program signal generator. In response to the output signal from the heating device, a heater which controls the temperature of the melt held in a vessel and which is arranged outside the vessel is heated according to the program.

Method and apparatus for manufacturing single crystals

A heating resistor of a single crystal manufacturing apparatus, which comprises a cylindrical side wall portion surrounding a melting pot, a bottom portion supporting the side wall portion, and a plurality of slits formed in the side wall portion and bottom portion, wherein said bottom portion has a maximum thickness which is not greater than that of said side wall portion, and said bottom portion has a minimum inner diameter which falls within a range of 20 to 80% of an inner diameter of a lowermost portion of said side wall portion.

Heating resistor of single crystal manufacturing apparatus

A gallium phosphide single crystal is prepared from a polycrystalline gallium phosphide powder as a starting raw material which is obtained by hydrogen reduction of gallium phosphate and which contains residual phosphate radicals in an amount of 0.03 to 0.5% by weight. The gallium phosphide powder is compressed to prepare a green compact which is then melted to provide a gallium phosphide liquid. The gallium phosphide liquid is brought into contact with a seed crystal and is pulled.

Growing community of inventors

Yokohama, Japan

Jisaburo Ushizawa