AVS 53rd International Symposium
    Vacuum Technology Tuesday Sessions
       Session VT-TuP

Paper VT-TuP2
A Diagnostic Technique for Particulate Deposits in the Pipes within the CVD System

Tuesday, November 14, 2006, 6:00 pm, Room 3rd Floor Lobby

Session: Vacuum Technology Poster Session
Presenter: J.Y. Yun, Korea Research Institute of Standards and Science
Authors: J.Y. Yun, Korea Research Institute of Standards and Science
J.H. Lee, Konkuk University, Korea
D.K. Moon, Konkuk University, Korea
S.W. Kang, Korea Research Institute of Standards and Science
D.-J. Seong, Korea Research Institute of Standards and Science
Y.H. Shin, Korea Research Institute of Standards and Science
Correspondent: Click to Email
In order to investigate the pipe clogging due to the particulate deposits in the CVD system, the various tests were conducted using the ultrasonic sensor and the vibration sensor system. At first, the pipe was examined with the ultrasonic sensor where the peak amplitude was observed to decrease as the particulate deposits increased. This is only applicable to the early stage where the particulate deposits are absorbing the ultrasonic energy. However, this trend would only last for a short period of time. The ultrasonic diagnostics would not be effective anymore when such samples are placed in a vacuum for two weeks. In this case, no particulate deposits were identified through the re-examination. This is attributed to particulate deposits drying off from the wall after some time, hindering particulate deposits from absorbing the ultrasonic energy and reflecting the ultrasonic wave back instead. As a result, this method will fail because it will not be able to differentiate the measurement from the reference sample. On the other hand, the vibration diagnostics system was able to show distinct differences depending on the amount of particulate deposits. The amount of particulate deposits could be detected by closely observing that the clean pipe achieves a high-level frequency with the impulse given by the vibration generator, while this frequency greatly reduces as the particulate deposits inside the pipes increase. It is believed that the vibration method can be applied to examine the pipes regardless of the conditions whether or not the particulate deposits are attached to the inner wall of pipes. This research also suggests that this method could be further investigated for effective application in monitoring the semi-conductor production line.