Patent ID: 6505635
Filing Date: 2003-01-14
Classification: B23Q,B24B,H01L,Y10S

Abstract:
Apparatus for lifting a wafer that has been lowered in a horizontal attitude from an initial position to a lowest position while rinsing the underside of the wafer, comprising:a hollow cylinder located below the wafer, and having a closed lower end, and having an open upper end that is spaced below the wafer when the wafer is in the lowest position; a spool having an upper end and a lower end and a passage extending through the spool between the upper end and the lower end, the spool being configured for axial motion within the hollow cylinder from a lower position in which the upper end of the spool is spaced below the lowest position of the wafer to an upper position in which the upper end of the spool extends above the upper end of the hollow cylinder; and, a supply for supplying fluid under pressure into the hollow cylinder adjacent to the closed lower end of the hollow cylinder; whereby, as the wafer is being lowered toward the lowest position, the pressurized fluid flows through the passage and is discharged from the upper end of the spool, and when the wafer reaches the lowest position the wafer partially impedes the discharge, thereby increasing the pressure of the fluid in the hollow cylinder below the spool and applying an upward force on the spool sufficient to overcome the weight of the spool, causing the spool to rise from the lower position to the upper position and thereby to uplift the wafer on a cushion of the fluid that prevents contact between the spool and the wafer, and whereby the wafer is rinsed by the fluid.