C30B11/001

Device and method for continuous VGF crystal growth through reverse injection synthesis

The invention discloses a device and a method for continuous VGF crystal growth through reverse injection synthesis, relating to a device for preparing a semiconductor crystal and growing a single crystal, in particular to a method and a device for continuously growing the crystal in situ by using a VGF method and reverse injection synthesis. The device includes a furnace body, a crucible, a heat preservation system, a heating system, a temperature control system and a gas pressure regulation system, wherein the crucible is arranged in the furnace body, has a synthesis unit at its upper part, and has a crystal growth unit and a seed crystal unit at its lower part, and the synthesis unit is communicated with the crystal growth unit through capillary pores.

SYSTEM AND FABRICATION METHOD OF PIEZOELECTRIC STACK THAT REDUCES DRIVING VOLTAGE AND CLAMPING EFFECT

A system and method provides a piezoelectric stack arrangement for reduced driving voltage while maintaining a driving level for active piezoelectric materials. A stack arrangement of d.sub.36 shear mode <011>single crystals of both air X-cut and Y-cut 1:45 (20) arrangement are bonded with discrete conductive pillars to form a shear crystal stack. The bonding area between the neighboring crystal parts is minimized. The bonding pillars are positioned at less than a total surface are of the single crystal forming the stack. The stack fabrication is facilitated with a precision assembly system, where crystal parts are placed to desired locations on an assembly fixture for alignment following the preset operation steps. With the reduced clamping effect from bonding due to lower surface coverage of the discrete conductive pillars, such a piezoelectric d.sub.36 shear crystal stack exhibits a reduced driving voltage while maintaining a driving level and substantial and surprisingly improved performance.

Method for recharging raw material polycrystalline silicon
09670593 · 2017-06-06 · ·

A method for recharging raw material polycrystalline silicon which enables large chunks of polycrystalline silicon to be recharged to a CZ ingot growth process while preventing the CZ crucible from being damaged and restricting a decline of the dislocation free rate and the quality of the grown ingot. Polycrystalline silicon chunks are recharged by first forming cushioning layer silicon of smaller chunks. The cushioning layer of polycrystalline silicon chunks are deposited on a surface of the residual silicon melt in a crucible. Subsequently, large-sized polycrystalline silicon chunks are introduced onto the cushioning layer, the cushioning layer cushioning the impact due to dropping of the large-sized polycrystalline silicon chunks.

Melt purification and delivery system

An apparatus to purify a melt is disclosed. A first portion of a melt in a chamber is frozen in a first direction. A fraction of the first portion is melted in the first direction. A second portion of the melt remains frozen. The melt flows from the chamber and the second portion is removed from the chamber. The freezing concentrates solutes in the melt and second portion. The second portion may be a slug with a high solute concentration. This system may be incorporated into a sheet forming apparatus with other components such as, for example, pumps, filters, or particle traps.

Polycrystalline silicon and method of casting the same
09546436 · 2017-01-17 · ·

Casting polycrystalline silicon includes placing a bottomless cooling crucible divided at least partially in the axis direction into a plurality of parts in the peripheral direction and having an inner surface coated with a release agent containing nitrogen, in an induction coil of a chamber charged with an inert gas; melting a raw material of polycrystalline silicon in the bottomless cooling crucible by electromagnetic induction heating using the induction coil; and pulling out the molten silicon downward while cooling and solidifying it. Pullout of the solidified molten silicon is performed through adjusting the carbon concentration of the molten silicon to 4.010.sup.17 atoms/cm.sup.3 or more to 6.010.sup.17 atoms/cm.sup.3 or less, the oxygen concentration thereof to 0.310.sup.17 atoms/cm.sup.3 or more to 5.010.sup.17 atoms/cm.sup.3 or less, and the nitrogen concentration to 8.010.sup.13 atoms/cm.sup.3 or more to 1.010.sup.18 atoms/cm.sup.3 or less.