| 摘要 |
PURPOSE:To detect the finish of the reaction when performing the subject dry etching reaction automatically, simply and in an excellent sensitivity by a method wherein the decision for the finish of reaction is given at the moment when the amount of variation of the quantity of plasma light generated at the time of etching reaction to the time of reaction is reduced below the prescribed value. CONSTITUTION:In the performance of the plasmatic etching reaction, a specific gas, CF4 for instance, is inducted into a reaction tube, the gas is excited and plasma is generated, and as the excited ion in the plasma is reacted to the material to be etched, the plasma light has a characteristic beam of light which appears only in the period while the etching reaction is continued. Therefore, this transforming plasma light such as a fluorine radical light emission, for example, is detected and the finish of the etching reaction is determined when the differential value C of the function indicating the relation between the amount of plasma light emission and the reaction time reaches to a fixed value 1t. Accordingly, the point of time when the etching reaction is finished is automatically detected in an excellent sensitivity and a microscopic pattern can be obtained. |
