| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent intrusion of chemicals through the suction port or the fixing part of a spin chuck effectively by conducting a gas jet port provided at the circumferential fringe on the upper surface of the spin chuck to a gas supply part through a gas passage in the spin chuck. SOLUTION: A gas jet port 5 is provided over the entire circumference on the upper surface of the spin chuck. Nitrogen gas from a gas supply part flows from a gas pipe coupling port 6a through a gas chamber 6, a gas flow-in port 9, a gas passage 7 in a shaft and a gas passage 8 in the spin chuck, as shown by an arrow, and then introduced to the gas jet port 5. Jetted gas flows on the rear surface of a wafer A set on the upper surface of the spin chuck 1 in the outer circumferential direction. Consequently, chemical is prevented by the gas flow from reaching a suction port 4 and the lower part of the spin chuck 1 is enlarged like a skirt to the outside of a fixing part B. Since the gas is jetted through a gap 10 between the skirt part 1a and the fixing part B, intrusion of chemical through the gap 10 is also prevented.</p> |
