| 摘要 |
<p>PURPOSE:To reduce a running cost so as not to use a gas during a conveyance operation by forming the following: a claw which is moved forward and backward in a radial direction at an end edge part of a gas guide flange in accordance with a distance to a wafer to be chucked; a connection hole used to guide a gas existing under the flange to a gas suction route. CONSTITUTION:When a wafer W is loaded by using a wafer handling device, a valve 29 is opened, a compression sheet 26 is pushed, a spring 21 is compressed, a wafer-holding claw 2 is retreated to the outside and a gas guide flange 13 of a substrate 1 is lowered from above the water W before the flange 13 comes above the wafer W. During this lowering operation, a sensor 4 detects a distance up to the wafer W; a valve 15 is opened at a proper distance by a signal of a control box 3; a gas G is discharged from a gas discharge route 11; a gas suction route 12 sucks the gas G; the wafer W is leviated. The sensor 4 detects this levitation; the valve 29 is closed; the claw 2 is moved; the valve 15 is closed; a discharge and suction operation of the gas G is stopped.</p> |
