Method of generating cracks in polycrystalline silicon rod and crack generating apparatus
A method of generating cracks in a polycrystalline silicon rod, comprising: heating a polycrystalline silicon rod; and subsequently performing local portion cooling of the polycrystalline silicon rod to apply a refrigerant fluid onto a spot-like area of a surface of the polycrystalline silicon rod.
1. An apparatus of generating cracks in a polycrystalline silicon rod by heating the polycrystalline silicon rod and subsequently quenching the polycrystalline silicon rod, comprising:
a heating unit to heat a polycrystalline silicon rod; and
a local portion cooling unit by which a refrigerant fluid is applied onto at least one spot-like area of a surface of the polycrystalline silicon rod,
wherein each of the spot-like area has a diameter of not smaller than 0.20 D and not larger than 0.32 D, where D denotes a diameter of the polycrystalline silicon rod.
2. The apparatus of generating cracks in a polycrystalline silicon rod according to claim 1 , wherein
the local portion cooling unit includes nozzles which are arranged on both sides of the polycrystalline silicon rod, wherein
a plurality of nozzles are arranged with spaces between adjacent nozzles on each side of the polycrystalline silicon rod along a lengthwise direction of the rod such that a substantially middle position of each space between adjacent nozzles on a first side faces a nozzle on a second side.
3. The apparatus of generating cracks in a polycrystalline silicon rod according to claim 1 , further comprising
an entire portion cooling unit that makes a refrigerant substance contact an entire surface of the polycrystalline silicon rod.
4. The apparatus of generating cracks in a polycrystalline silicon rod according to claim 3 , wherein
the refrigerant substance is a refrigerant fluid.