Tokyo Shibaura Electric Co., Ltd.

Agency of Industrial Science and Technology

Tokyo Shibaura Denki Kabushiki Kaisha

Ministry of International Trade & Industry

Ministry of International Trade & Technology

Tsuguo Fukuda

Kazutaka Terashima

Hitoshi Hirano

Jisaburo Ushizawa

Syoichi Washizuka

Yoshihiro Kokubun

Masayuki Watanabe

Tooru Katsumata

Hiroaki Nakajima

A method for the production of a gallium arsenide single crystal which comprises bringing a seed crystal into contact with a fused layer of raw materials for the crystal while applying to the fused layer a magnetic field which has intensity enabling the temperature fluctuation in the neighborhood of the solid-liquid boundary in the fused layer to be repressed to within 1.degree. C., thereby effecting crystal growth.

Method for producing GaAs single crystal

The heater member of a furnace for heating the crucible used for fusing raw materials for a semiconductor single crystal is provided with reinforcing members made of a material such as alumina or pyrolytic boron nitride which excels in electric insulating property, resistance to heat, and strength. When a magnetic field with an alternating current or pulsating current of electricity is applied to the site of single crystal growth for the purpose of stabilizing the growth of the single crystal, the furnace tends to sustain breakage. These reinforcing members thus used on the heater member impart improved durability to the furnace and enable the apparatus as a whole to enjoy a long service life.

Apparatus for manufacturing semiconductor single crystal

A III-V group compound semiconductor single crystal is manufactured by a method which comprises adjusting the temperature of a fused layer of raw material for the crystal, based on the electric current signal flowing between a seed crystal and the fused layer of raw material for the crystal, the weight signal of the crystal, and the length signal of the crystal, to levels optimum for the growth of crystal during the contact of the seed crystal with the fused layer, during the formation of the shoulder part of the crystal, and during the formation of the barrel part of the crystal, respectively in the process of crystal growth.

Method for manufacture of III-V group compound semiconductor single

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 III-V compound semiconducting single crystal is manufactured by a method using an encapsulant, which method comprises allowing the molten mass of a material for the crystal melted in advance under high pressure to be placed under a pressure lower than the pressure to be exerted during the work of pulling the crystal thereby causing the molten mass to generate bubbles and allowing the departing bubbles to entrain impurities from the molten mass, bringing a seed crystal into contact with the molten mass, applying a potential to the molten mass thereby determining the impurity concentration of the molten mass based on the results of the measurement and, after the impurity concentration of the molten mass determined as described above has reached a prescribed level, initiating the work of pulling the crystal from the molten mass.

Method for manufacture of III-V compound semiconducting single crystal

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.

Method for manufacturing gallium phosphide single crystals

Apparatus for manufacturing single crystals

A method for producing a lithium tantalate single crystal comprises the steps of preparing a melt consisting essentially of lithium tantalate in a platinum-rhodium crucible including (20 to 35 weight percent of rhodium and 80 to 65 weight percent of platinum), and growing a lithium tantalate single crystal from the melt.

Method for producing a lithium tantalate single crystal

A method for preparing oxide piezoelectric material wafers from a rhombohedral single crystal of an oxide piezoelectric material as-grown cylindrically in the X-axis direction includes linearly rubbing-off at least one side portion of such as-grown cylindrical single crystal facing to a specified direction along the longitudinal direction of such single crystal before cutting X-cut wafers from such single crystal thereby to provide a corresponding flat portion.

Method for preparing oxide piezoelectric material wafers

A method for producing a lithium tantalate single crystal comprises the steps of preparing a melt consisting essentially of lithium tantalate in a platinum-rhodium crucible including 20 to 40 weight percent of rhodium, and growing a lithium tantalate single crystal from the melt in an oxidizing atmosphere, for example, in the atmosphere.

A method of producing a single crystal of lithium tantalate in a platinum-rhodium crucible containing 20 to 40% by weight of rhodium in an atmosphere of reducing or inert gas.

Lithium tantalate single crystal growth from a platinum-rhodium crucible

A method of growing multiple monocrystalline layers from melts comprising growing a first monocrystalline layer from the first melt, and growing a second monocrystalline layer on the first monocrystalline layer from the second melt by successively contacting the first monocrystalline layer with the second melt during the growth of the first monocrystalline layer.

Growing community of inventors

Yokohama, Japan

Tsuguo Fukuda