| 摘要 |
<p>Anomalous discharge during a plasma processing and its position is specified by arranging a plurality of ultrasonic-wave detecting means in the structural components of a plasma processing chamber, measuring the ultrasonic wave generated by the anomalous discharge with the ultrasonic-wave detecting means, comparing the sensor outputs of the ultrasonic-wave detecting means on the same time axis, and determining the difference in propagation time and the maximum amplitude of the ultrasonic-wave detecting means, and the display and the alarm are given. Only four ultrasonic-wave detecting means installed on the wall surface of the processing chamber are used because an iterative asymptotic calculation is performed of a relation between the difference in the propagation time and the distance from the anomalous discharge source. The lower cover of a hold case is bonded to a specified position of the processing chamber, while an AE sensor is pressed by appropriate pressure from the upper inner side.</p> |
