Patent ID: 6914222
Filing Date: 2005-07-05
Classification: H01L,H05B

Abstract:
1. A wafer heating apparatus comprising: a ceramic plate having a front surface of the ceramic plate serving as a mounting surface for mounting a wafer and a recess formed in the ceramic plate opening to a rear surface of the ceramic plate; a resistance heating element attached on the rear surface of the ceramic plate or buried within the ceramic plate; a recess formed in the rear surface of the ceramic plate; a temperature measuring member including a temperature sensor, leads for connecting the temperature sensor and a protective tube for covering the temperature sensor, the protective tube being inserted in the bottom side of the recess; and a filling which is inserted in the recess to hold the protective tube secured therein; wherein a length along the leads from the front end of the protective tube to a point where the leads are exposed from the end portion of the filling is set in a range of 5 to 30 times the outer diameter of the protective tube, wherein the shortest distance from the center of the temperature sensor to the heat resistance element is sat to satisfy the following relationship: where L