| 摘要 |
PROBLEM TO BE SOLVED: To provide a disc heater and a wafer treatment device that suppress abnormal heating at the periphery of the disc heater at rapid increase of temperature, and have a uniform temperature distribution at normal condition, and can prevent migration of the disc insulation substrate. SOLUTION: The disc heater comprises heater resistor having a positive resistance temperature coefficient arranged in nearly concentric shape inside the disc insulation substrate 2 and the beat density at the periphery of the insulation substrate 2 is established higher than that of the center portion. The resistance temperature coefficient of the heater resistor 6a provided at the periphery of the insulation substrate 2 is smaller than the resistance temperature coefficient of the heater resistor 6b provided at the center portion, and the volume specific resistance of the heater 6a at the room temperature is higher than that of the heater resistor 6b, and the resistor bodies 6a, 6b disposed at the center portion and the periphery portion are connected in parallel.
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