On the impurity distribution in a thin silicon rod grown by pulling from a melt on pedestal

Abstract

Thin polycrystalline silicon rods of 4–7 mm diameter and 50–60 cm lengt using the pedestal technique. Distribution of impurities in a thin rod has been found to obey the relation C f / C 0=1-(1- k) exp(- kβ/1) where C f and C 0 are the impurity concentration in the thin and pedestal rod, respectively; k is the effective segregation coefficient of the impurity, l is the length of the molten zone, x is the rod length and α is a constant dependent on the ratio of the pedestal to thin rod diameter.