Patent ID: 6897415

Claim:
Workpiece stage of a resist curing device comprising a heating means, a cooling means and a vacuum suction means, the heating and cooling means cycling the temperature of the workpiece stage between 80 to 130° C. and 200 to 250° C. repeatedly, wherein the workpiece stage is of at least 300 mm in diameter and is made of a material which is chosen from the group consisting of an aluminum alloy and a copper alloy which meets the following condition: σ/σ y ≦3.1, where σ is thermal stress as determined using the following formula: σ= EαΔT where E is Young's modulus (N/mm 2 ) at 200° C., α is a coefficient of linear expansion (1/° C.) at 200° C. and ΔT is a temperature difference (° C.) of 120° C., and σ y is a fracture point at 200° C. for preventing warping of a peripheral area of the workpiece stage relative to a center area thereof by more than 0.5 mm for the workpiece stage due to the repeated cycling of said heating and cooling means.