| 摘要 |
<p>PURPOSE:To enhance machining accuracy by making a recess in the center of a chuck and bringing a wafer into contact with the wafer mounting face on the periphery of the chuck thereby heating only the peripheral part of the wafer. CONSTITUTION:A recess 13 is made at the center on the top surface of a chuck 11 leaving the wafer mounting face 12 on the periphery thereof. When a wafer applied with resist is mounted on the chuck 11, heat is transmitted from the chuck 11 to the wafer only through the wafer mounting face 12 where the chuck 11 abuts on the wafer. Since heat does not transmit directly from the recess 13, central part of the wafer corresponding to the recess 13 is not heated or hardly susceptible to heating. Consequently, machining accuracy is enhanced and fluctuation is suppressed in the finish of pattern. Introduction of chill air into the recess prevents heating at the center of wafer more positively.</p> |
