摘要 |
<p>A ceramic substrate which is free from cracking or warping on heating or cooling quickly, from location-dependent variations in chucking force when the ceramic substrate constitutes an electrostatic chuck, from location-dependent variations in wafer treatment surface temperature when the ceramic substrate constitutes a hot plate, and from variations in voltage applied to guard electrodes or ground electrodes when the ceramic substrate constitutes a wafer prober to permit the removal of stray capacity or noise, and which comprises a conductive layer disposed on the surface or inside thereof, characterized in that a ratio (t2/t1) of an average conductive-layer thickness (t2) to an average ceramic-substrate thickness (t1) is less than 0.1, and variations in thickness from an average conductive-layer thickness range from 70 to +150%.</p> |