Mitsubishi Materials Corporation

Jun-ichi Sasaki

Saburo Wakita

Akira Mitsuhashi

Yoshinobu Nakada

Yuhji Ishiwari

A mold for producing a silicon ingot having a layered structure comprising an inner silica layer containing at least one layer in which a fused silica powder with a particle size of 100 &mgr;m or less and a fine fused silica sand with a particle size of 100-300 &mgr;m is bonded with a silica binder, and an outer silica layer containing at least one layer in which a fused silica powder with a particle size of 100 &mgr;m or less and a coarse fused silica sand with a particle size of 500-1500 &mgr;m is bonded with a silica binder.

Mold for producing silicon ingot and method for fabricating the same

A method for producing a silicon ingot having a directional solidification structure comprising the steps of: placing a silicon raw material into a crucible of a melting device constructed by mounting a chill plate on an underfloor heater, mounting a crucible with a large cross-sectional area on the chill plate, providing an overhead heater over the crucible, and surrounding the circumference of the crucible with a heat insulator; heat-melting the silicon raw material by flowing an electric current through the underfloor heater and overhead heater; chilling the bottom of the crucible by halting the electric current through the underfloor heater after the silicon raw material has been completely melted to form a molten silicon; chilling the bottom of the crucible by flowing an inert gas through the chill plate; and intermittently or continuously lowering the temperature of the overhead heater by intermittently or continuously decreasing the electric current through the overhead heater, and an apparatus for producing the silicon ingot.

Growing community of inventors

Omiya, Japan

Jun-ichi Sasaki