| 摘要 |
<P>PROBLEM TO BE SOLVED: To measure the thickness of a wafer with good accuracy using a non-contact thickness sensor by favorably removing a water film formed on the surface of a wafer even in a wafer grinder. <P>SOLUTION: First and second air nozzles 15, 17 are disposed on the upstream side in the rotating direction of the wafer 5 on a circumference formed around the center of rotation of the wafer 5, to which a measurement point 23 belongs, and have the same construction. Clean air supplied at predetermined pressure from an air supply device having two or more linear small-diameter circular holes is jetted from the respective circular holes toward an area including the above circumference on the surface of the wafer 5 rotated in one direction. In the second air nozzle 17, the respective circular holes are disposed along the tangential direction of the circumference. In the first air nozzle 15, linear two or more small-diameter circular holes are disposed in the state of being not at right angles and parallel to the tangent of the circumference such as an angle about 45 degrees. <P>COPYRIGHT: (C)2007,JPO&INPIT |
