REFERENCES

crystal diameter is that for smaller crystal diameters the edge effects are of increasing importance, i.e., the rotating disk analysis ceases to be valid and the boundary layer thickness becomes a function of the radius. Summary The radial solute segregation in Czochralski-grown silicon crystals has been shown to be greatly in-fluenced by the effects of secondary liquid flow in the outer regions of the solid-liquid interface. The exist-ence of interface facets will also cause large radial segregation because of the orientation dependence of the equil ibrium distribution coefficient. However, the effects of liquid flow must be studied independently if unambiguous information is required on the facet effect alone. Maximum radial solute uniformity is possible only when the diffusion boundary layer at the growing interface is primari ly controlled by crys-tal rotation, when the factor Oke/08 for the solute is insensitive to changes in 5 at any particular growth rate and when the crystal orientation does not permit the development of an extensive close-packed inter-face facet on an otherwise curved interface