AVS 66th International Symposium & Exhibition
    Vacuum Technology Division Tuesday Sessions
       Session VT-TuP

Paper VT-TuP3
Fabrication and Characterization of a Variable Conductance Vacuum Valve to Control Pressure Level for a High Vacuum System

Tuesday, October 22, 2019, 6:30 pm, Room Union Station B

Session: Vacuum Technology Poster Session
Presenter: Han Wook Song, Korea Research Institute of Standards and Science, Republic of Korea
Authors: H.W. Song, Korea Research Institute of Standards and Science, Republic of Korea
S.Y. Woo, Korea Research Institute of Standards and Science, Republic of Korea
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Fabrication of a semiconductor device requires a high precision and a high degree of cleanliness. For this reason, the semiconductor device is manufactured in a state in which the contact of the foreign substances contained in the air is completely blocked, that is, in a vacuum state (approximately around 0.1 Pa.) To adjust the required vacuum level, some apparatus such as a needle valve, a gate valve, and a butterfly valve were used to control the gas flow. Recently, we developed a variable-conductance vacuum valve to control the inlet pressure for vacuum chamber, which was modified from optical iris used in optics. The present conductance variable valve is characterized in that the conductive tuck adjusting portion and the conductance operating portion employing the iris structure do not have a physically contacted or coupled structure. And the housing has no mounting holes, fastening holes, or the like for coupling the conductance operating portions, so it has a conductance variable function that can completely block the fluid leakage of the valve without any separate parts such as packing, sealing, and O-ring. The guide section of the housing will have a first magnetic body, while the conductance control unit will have a second magnetic body in the mounting hole. Therefore, when the first body and the second body are moved in a circular direction by the attraction force, the first body within the guide unit also moves in a circular direction. The cross sectional area of housing and the conductance of fluid are proportional. When using the manufactured variable valve, it showed 2% reproducibility and 0.5% repeatability in pressure generation. In the future, we will make and evaluate a large variable valve that can be applied to high vacuum systems.