The distribution of Ga and Sb impurities in Ge-Si crystals grown by the Bridgman method using a feeding rod

Gallium- and antimony-doped Ge_{1 ? x} Si _x crystals (0 ≤ x ≤ 0.25) have been grown by the improved Bridgman method using a silicon seed and a macrohomogeneous feeding Ge-Si rod of the corresponding composition. The impurity concentration profiles along the grown crystals were determined from Hall measurements. The mathematical problem of impurity distribution along two-component mixed crystals grown from a melt with uniform and graded composition is solved in the Pfann approximation and within the virtual-crystal model for the solid solution. It is shown that the experimental impurity distributions in Ge_{1 ? x} Si _x crystals are described well by the data calculated on the assumption of linear change in the impurity segregation coefficient with the crystal composition.