한국정밀공학회:학술대회논문집 (Proceedings of the Korean Society of Precision Engineering Conference)
- 한국정밀공학회 2003년도 춘계학술대회 논문집
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- Pages.969-974
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- 2003
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- 2005-8446(pISSN)
릴레이 제어법을 이용한 실리콘 웨이퍼의 정전부상에 관한 연구
Electrostatic Suspension System of Silicon Wafer using Relay Feedback Control
초록
A simple and cost-effective method for the electrostatic suspension of thin plates like silicon wafers is proposed which is based on a switched voltage control scheme. It operates according to a relay feedback control and deploys only a single high-voltage power supply that can deliver a dc voltage of positive and/or negative polarity. This method possesses the unique feature that no high-voltage amplifiers are needed which leads to a remarkable system simplification relative to conventional methods. It is shown that despite the inherent limit cycle property of the relay feedback based control, an excellent performance in vibration suppression is attained due to the presence of a relatively large squeeze film damping origination from the air between the electrodes and levitated object. Using this scheme, a 4-inch silicon wafer was levitated stably with airgap variation decreasing down to 1
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