CERAMIC HEATER

摘要

A ceramic heater which is high in heat conductivity, can allow a surface temperature of a heater plate to quickly keep up with a heating body's temperature change, can control a wafer heating surface temperature optimally and can prevent a thermal diffusion of impurities (such as Y) from a ceramic heater to a semiconductor wafer, and which comprises a heating body provided on the surface of, or inside, a nitride ceramic substrate, characterized in that the above nitride ceramic substrate contains elements other than constituent elements of nitride ceramics, and a JIS B 0601-based surface roughness of a heating surface on which a substance to be heated such as a semiconductor wafer is placed or retained is Rmax = 0.2 to 200 mu m.