| 摘要 |
PURPOSE:To enhance the accuracy of analyzation by a method wherein evaporation speed is increased by attaching a heater on the container in which working liquid is contained, and a cooling liquid is supplied to the circumference of a decomposed liquid receiving vessel. CONSTITUTION:A wafer 24 is placed on a wafer carrier 25, they are placed in an airtight container 20 and left in that state for the prescribed period. At this time, as the container 22 wherein a working liquid 21 is contained is heated up to approximately 40-50 deg.C by a heater 23, a large quantity of hydrofluoric acid is evaporated, and a semiconductor thin film 26 is completely decomposed at a high speed by the vapor 31. As a result, the decomposed liquid 32 is conveyed on the surface of the semiconductor thin film 26, drops and collected in a decomposition liquid receiving plate 28. At this time, as the decomposition liquid receiving plate 28 is cooled by the cooling liquid running in a cooling liquid feeding tube 30, the reevaporation of the decomposition liquid 32 collected once in the decomposition liquid receiving plate 28 can be suppressed. Then, said decomposition liquid 32 is recovered, stirred up, weighed and the qualitative and quantitative determinations for impurities are performed using a flameless atomic absorption spectroscopic device. As a result, the decomposition time of the semiconductor thin film can be reduced, the reevaporation of the decomposition liquid can be prevented, and the analytical accuracy can also be improved. |
