NUMERICAL AND EXPERIMENTAL-STUDY OF A SOLID PELLET FEED CONTINUOUS CZOCHRALSKI GROWTH-PROCESS FOR SILICON SINGLE-CRYSTALS

A polysilicon pellets ( congruent-to 1 mm diameter) feed continuous Cz ochralski (CCZ) growth process for silicon single crystals is proposed and investigated. Experiments in an industrial puller (14-18 inch dia meter crucible) successfully demonstrate the feasibility of this proce ss. The advantages of the proposed scheme are: a steady state growth p rocess, a low aspect ratio melt. uniformity of heat addition and a gro wth apparatus with single crucible and no baffle(s). The addition of d opant with the solid charge will allow a better control of oxygen conc entration leading to crystals of uniform properties and better quality . This paper presents theoretical results on melting of fully and part ially immersed silicon spheres and numerical solutions on temperature and flow fields in low aspect ratio melts with and without the additio n of solid pellets. The theoretical and experimental results obtained thus far show a great promise for the proposed scheme.