Crystal, and method and device for casting same

Abstract

The invention generally relates to a crystal casting method using seed crystals, such as a directional solidification casting method. The crystal casting method includes a temperature gradient solidification method for manufacturing larger crystal materials in preset crystal orientation, wherein the crystal materials include polycrystalline materials and monocrystalline materials, and particularly include silicon or silicon germanium materials applicable to semiconductor and photovoltaic application. An existing crystal casting method using seed crystals has the problems of high energy consumption, more control difficulty, more impurity particles, easiness in generating mixed crystals, difficulty in obtaining large-sized monocrystalline materials and the like. The crystal casting method solves the problems by the aid of a bottomless crucible or a crucible with a notch at the bottom, a heat insulation area and a heat insulation position, fine crystal growth effect is achieved, the obtained casting monocrystalline or polycrystalline materials such as silicon or silicon germanium crystals have fewer defects or impurities, fine quality and excellent performance, and are applicable to the semiconductor and photovoltaic field.

Description

technical field [0001] The present invention generally relates to crystal casting methods using seed crystals, such as directional solidification casting methods, including temperature gradient solidification methods, such as vertical temperature gradient solidification methods (hereinafter also referred to as VGF methods) or vertical Bridgman methods (hereinafter also referred to as VGF methods) The VB method) or the Vertical Bridgeman Stoke Barger method (VBS method) produce relatively large crystalline materials of predetermined orientations, including polycrystalline and monocrystalline materials, especially suitable for semiconductor and photovoltaic applications such as silicon or Silicon germanium material. Background technique [0002] Crystalline materials have excellent properties for industrial applications based on their specific microstructure, which tend to be pursued as much as possible in the manufacture of crystals. Taking crystalline silicon materials as a...

AI Technical Summary

Problems solved by technology

However, this method has so far only been used to grow crystals with relatively small sizes, especially crucibles with good thermal conductivity such as molybdenum and tungsten metals or graphite, and has not been used to grow large-sized silicon single crystals.

At larger sizes, the control of the temperature gradient becomes difficult to achieve due to the thermal conductivity of the seed crystal and the resulting crystal and the heat dissipation problem at the bottom of the crucible

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