[15p-D419-1~8] 15.1 Bulk crystal growth

[15p-D419-6] COP distinctive low-density distribution in a dislocation-free Si ingot grown by NOC

〇Kazuo Nakajima¹, Masami Nakanishi², Martin Su², Chuck Hsu² (1.IMR, Tohoku Univ., 2.GlobalWafers Ltd.)

Keywords:Si bulk ingot growth, COP density, NOC growth method

The NOC method has a large low-temperature region in Si melt. The cross point of vacancy (C_V ) and interstitial Si atom (C_I ) is very important to reduce the point defects in NOC ingot. The theoretical simulation pointed out that the lowest vacancy or interstitial Si atom area appears in the region with the smaller ratio between temperature gradients at melt surface and growing interface. The growth condition to obtain this region is suitable for the NOC method. The quality of a NOC ingot was first evaluated by determining the distribution of COP in the cross section of the dislocation-free ingot. In comparison with the distribution of COP in Cz and NOC ingots, COP cannot be detected inside the ring-OISF in the NOC wafer under the same etching process as many COP can be observed in the Cz wafer.