Equilibrium segregation coefficient and solid solubility of B in Czochralski Ge crystal growth

This paper reports reevaluated results of the segregation coefficient of boron (B) and a solid solubility of B at melting point of Ge. The crystal growth was carried out from a B-saturated Ge melt, and a solid solubility of B in Ge crystal was estimated to be 3 ± 0.5 × 10¹⁸ cm^{- 3}. The effective segregation coefficients of 4 and 2.5 were obtained at pulling rates of 10 and 30 mm/h, respectively. An equilibrium segregation coefficient was estimated to be 6.2 and it was considerably smaller than those reported previously. Therefore, boron atoms in Ge melt easily interact with residual O atoms existing in the Ge melt, resulting in various values reported of the segregation coefficient. A phase diagram of Ge and B at Ge-rich region estimated from obtained experimental results is proposed.