[1] Ota M.Mag-Lev semiconductor wafer transporter for ultrahigh-vacuum environment.in Proc 2nd Int Symp Magnetic Bearings,Tokyo,Japan,1990:109~114
[2] Ford R G,Koh A S.Noncontact semiconductor wafer handling.in Proc Soc Manuf Eng Annu Meeting 1990:1~10
[3] Hashimoto Y.Noncontact substance transportation using acoustic levitation.in Proc 7th Symp Electromagnetics and Dynamics,Nagasaki,Japan,1995:449~454
[4] Brandt E H.Levitation in physics,Science Jan,1989,243:349~354
[7] Hamamatsu Co.Position-sensitive Detectors.Japan,October 1985:9~13