Patent ID: 9670593
Date: 2017-06-06
CPC Classifications: C30B,Y10T

Claim:
1. A method for recharging raw material polycrystalline silicon to a residual silicon melt in the CZ process for producing a silicon single crystal ingot, wherein a filling step of filling raw material polycrystalline silicon into a crucible, a melting step of melting filled polycrystalline silicon in the crucible to form a silicon melt, and a pulling-up step of bringing a seed crystal into contact with the silicon melt and pulling up the seed crystal to thereby grow a silicon single crystal ingot is used, and wherein further raw material polycrystalline silicon is supplied into the crucible after the melting step and the pulling-up step, the method comprising forming a cushioning region by introducing middle-sized polycrystalline silicon chunks having sizes of 20 mm to 50 mm and a maximum width h of 50 mm to the surface of the silicon melt in the crucible, and subsequently supplying large polycrystalline silicon chunks larger in size than the middle-sized polycrystalline silicon chunks onto the cushioning region, wherein the cushioning region entirely covers the surface of the silicon melt prior to supplying the large silicon chunks.