Analysis of Deposits Evaporated from Boron-Doped Silicon Melt

The influence of the addition of boron on weight variation of silicon melt due to evaporation was investigated. It was found that the evaporation loss of the 1021 atoms/cm3 boron-doped silicon melt was larger than that of non-doped silicon melt. In particular, it appeared that boron enhanced the weight variation of the silicon melt at high temperature (1550° C) by assisting the evaporation from the melt. Deposits collected by a well designed collector were analyzed by electron probe microanalysis (EPMA) in order to identify the chemical species evaporated from the boron-doped silicon melt. It was found that the predominantly evaporated species from the boron-doped silicon melt was silicon oxide. It could be concluded that the addition of boron into the silicon melt enhances the evaporation of silicon-oxide.