| 摘要 |
PROBLEM TO BE SOLVED: To provide an etching apparatus that prevents reduction in electrostatic adsorption force with a holding means in which a coolant channel is provided. SOLUTION: The etching apparatus etches a back of a workpiece W of which the surface is attached with a protection tape. The etching apparatus has the holding means 30 for holding the workpiece W, which is placed with the back being upward, by electrostatic adsorption, and a cooling means 50 for cooling a protection tape 31 via the holding means 30 by circulating coolant through a coolant channel 36 provided within the holding means 30. Furthermore, the cooling means 50 has a detection means 58 for detecting ion concentration in the coolant, and an ion concentration control means 60 for controlling the ion concentration in the coolant based on the detection results given by the detection means 58. Thus, since the ion concentration in the coolant is maintained at a low level, leakage current to the coolant is suppressed, consequently electrostatic adsorption force of the holding means is not reduced. COPYRIGHT: (C)2005,JPO&NCIPI |
