Contactless magnetically levitated silicon wafer transport system

Abstract

A new magnetically levitated wafer transport system is developed for the semiconductor fabrication process to get rid of the particle and oil contaminations that normally exist in conventional transport systems. The transport system consists of levitation, stabilization tracks, and a propelling system. Stabilities needed for levitation in the transport system are achieved by an antagonistic property produced in the tracks and using a simple feedback control. The continuous propelling force is obtained by sending specific current patterns to the propulsion coils. The dynamic model of the transport system is presented and analyzed. Copyright (C) 1996 Elsevier Science Ltd.