CAVITIES OWING TO HYDROGEN IN SI SINGLE-CRYSTALS GROWN BY CONTINUOUSLY CHARGING CZ METHOD

The quality of Si single crystals with a diameter of up to 150 mm in t he length between 1 m to 1.5 m, grown by continuously charging Czochra lski (CCZ) method, is studied and the Possibility of CCZ method is dis cussed. The profile of interstitial oxygen concentration (O-i) is almo st constant along the growth direction. The profile of precipitated O- i exhibits a slight decrease along the first half of the crystal lengt h, and a more remarkable decrease along the latter half. Many pits wit h a diameter up to 15 mu m are observed on a chemically polished surfa ce of Si CCZ wafer. We believe the origin of these pits is cavities fo rmed during CCZ crystal growth owing to hydrogen contained in raw gran ular polycrystalline Si. Besides the cavity problem, we have to solve some serious cost problems to apply CCZ method for actual production.