Wafer heating apparatus

摘要

In order to achieve concentric distribution of temperatures over a wafer supporting surface and improve the uniformity of heating, a heating resistor 4 having a configuration for providing a predetermined heater pattern buried in a ceramic substrate 2 constituting a wafer heating apparatus is made from arc portions 4a-4g which have different radii and are arranged to form concentric circles disposed at substantially the same intervals and straight portions 4h-4m which connect those of the arc portions 4a-4g that are adjacent to each other in the radial direction thereby to form a series circuit, while the arc portions 4a-4g and the straight portions 4h-4m are made in substantially the same strip width and the distance L1 between a pair of straight portions among the straight portions 4h-4m which are located on the same circle is made less than the distance L2 between the arc portions which are adjacent to each other in the radial direction.