Microstructure and resistivity of the silicon target material prepared by adding Al-B master alloy

摘要

A silicon target material with the purity of 99.999 wt% (99.999%) was prepared by adding Al-B master alloy in directional solidification. The segregation behavior of the dopant and the effect on the resistivity were studied in this work. It was revealed that the A1B_2 particles in the Al-B master alloy will generate the clusters of [B] and [Al] in molten silicon at 1723 K spontaneously. The concentrations of B and Al were increasing gradually along the solidified fraction in the silicon ingot. The measured values of B were in good agreement with the curve of the Scheil's equation below 85% of the solidified fraction. The measured values of Al were fitting well with the curve of the Scheil's equation when the effective segregation coefficient is 0.00378. It was found that the resistivity of the silicon target material was regulated by B co-doped Al simultaneously in directional solidification.