Patent ID: 8490901

Claim:
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 at least one spot-like area of a surface of the polycrystalline silicon rod, wherein ejecting the refrigerant fluid from nozzles arranged on both sides of the polycrystalline silicon rod; 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, so as the refrigerant fluid to be applied to a plurality of positions dispersed on the surface of the polycrystalline silicon rod; and each of the spot-like area has a diameter of not smaller than 0.20D and not larger than 0.32D, where D denotes a diameter of the polycrystalline silicon rod.