| 摘要 |
PROBLEM TO BE SOLVED: To appropriately control the temperature of a substrate and the flow rate of a gas when a crystal growth system shifts to the next crystal growing step from an oxide film removing step, by controlling the system by monitoring a protection oxide film removing step by means of ellipsometry. SOLUTION: After an Si substrate with protection oxide film is abruptly heated to, for example, 800 deg.C in a vacuum vessel and held as it is for 30 minutes, the Si substrate is cooled to the room temperature and the alteration of the substrate while the substrate is cooled is observed by means of ellipsometry which measures the polarized state of reflected lights by irradiating the substrate with polarized light having energy of, for example, 2.5 eV. The Si substrate reaches 800 deg.C from the room temperature when the substrate is heated for about 150 seconds. Of the 30 minutes (300-2,100 seconds) during which the temperature of the Si substrate is maintained at a fixed temperature,ΨandΔchange following the reduction in thickness of the oxide film and, when the removal of the protection oxide film is completed, the variation of theΨandΔdisappears. Therefore, the completion of the removal of the protection oxide film can be detected by means of the ellipsometry.
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