Patent ID: 6956186
Filing Date: 2005-10-18
Classification: G05D,H01L,H05B

Abstract:
1. A ceramic heater for heating a semiconductor wafer, comprising: a ceramic substrate having a first surface and a second surface, the first surface being arranged as a heating face configured to heat the semiconductor wafer; a resistance heating element formed on the second surface of said ceramic substrate or inside said ceramic substrate, and including at least two circuits; temperature-measuring means for measuring a temperature of said ceramic substrate or a temperature of the semiconductor wafer; a control unit configured to supply electric power to said resistance heating element; a memory unit configured to store the temperature data measured by said temperature-measuring means; and an operation unit configured to calculate, based on said temperature data, electric power data required for said resistance heating element to attain a uniform temperature of the heating face, wherein different electric power is supplied to each of the at least two circuits based on the calculated electric power data.