Apparatus for transporting wafer to and from polishing head

Claim 1

Apparatus for fluid transport of a wafer from the pressure head of polishing apparatus into a cassette for storing the wafer, said wafer including a peripheral edge circumscribing said wafer, and spaced apart top and bottom surfaces each terminating at said edge, said polishing apparatus including at least one station having a polishing surface, a frame, and elongated carrier means mounted on said frame to move said pressure head between at least two operative positions, a first operative position with said head positioned over said transport apparatus, and a second operative position with said head positioned over said station, said pressure head including a lower portion for maintaining the wafer in contact therewith and against said polishing surface when said pressure head is positioned over said station, said fluid transport apparatus including (a) a housing; (b) a reservoir formed in said frame to receive the wafer released from said pressure head when said pressure head is in said first operative position, said reservoir including (i) a floor, and (ii) sloped side surfaces extending upwardly away from said floor to receive and contact at least selected portions of said peripheral edge of said wafer to prevent said bottom surface from contacting said floor of said reservoir; (c) an elongate channel formed in said housing in fluid communication with said reservoir to receive a wafer therefrom, said channel including (i) a floor, (ii) elongate, opposed, spaced apart sloped side surfaces extending upwardly away form said floor of said channel to receive and contact portions of said peripheral edge of said wafer to prevent said bottom surface from contacting said floor of said channel when said wafer moves along said channel, and (iii) a wafer-dispensing end; (d) orifice means formed in said housing to direct fluid under pressure into said reservoir to flow through said reservoir, through said elongate channel, said fluid flow carrying the wafer from said reservoir to and out of said dispensing end; (e) a second reservoir to receive fluid flowing out of said dispensing end of said channel; (f) cassette means in said reservoir to receive a wafer moving out of said dispensing end toward said cassette means, said cassette means including surfaces for slidably receiving portions of said peripheral edge of the wafer.