| 摘要 |
PROBLEM TO BE SOLVED: To enable cooling without generating a large temperature difference on a wafer placement surface.SOLUTION: A ceramic heater 20 includes a ceramic base 22 having a wafer placement surface 22a, a resistance heating body 28 incorporated in the ceramic base 22, a cooling passage 30 formed in the ceramic base 22, and a gas introduction path 34 for introducing cooling gas in the cooling passage. The gas introduction path 34 includes a gas pipe 36 extending in a hollow of a shaft 40 from below toward the ceramic base 22, and a nozzle 38 provided to a tip of the gas pipe 36. A tip side of the gas pipe 36 curves along the cooling passage 30 to change in direction by about 90°. Because of a curving part 36a, the cooling gas having passed through the gas introduction path 34 avoids striking on the ceramic base 22. |
