| 摘要 |
PURPOSE:To permit such measurement which minimizes thermal influence of a coating material in measurement of the thermal diffusivity of a silicon melt by specifying the thickness of boron nitride to 150-180mum. CONSTITUTION:The thickness of the boron nitride is specified to 150-180mum in the measurement of the thermal diffusivity of the silicon melt. The boron nitride has high heat conductivity and can transmit the calorific value by energization of a fine platinum wire quickly to a semiconductor melt to be measured even if the fine platinum wire is coated with the aluminum nitride. For example, the surface of the fine carbon wire having 200mum diameter is coated with the boron nitride to 150mum thickness and the thermal diffusivity of the molten silicon is measured by a nonstationary fine wire method using such fine wire as the probe in common use as a heating element. The thermal diffusivity can then be measured at 2% error as compared to the theoretical value of the case in which there is no coating material. The measurement error by the presence of the coating material is, therefore, restricted within a permissible range.
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