| 摘要 |
<p>PURPOSE:To enable durability to be improved, prevent a foreign object from being adhered to, and achieve a stable plane correction of a wafer by providing a negative-pressure groove for sucking the wafer on a wafer-mounting surface side, constituting a base material with ceramic, and then coating the wafer mounting surface with a material other than porosity whose hardness is greater than that of the wafer. CONSTITUTION:A wafer on a chuck surface 1 is retained by a negative-pressure groove 2 and a negative pressure is supplied from a chuck rear surface 6 through a hole 4. Plane correction of the wafer is performed by the chuck surface 1 by performing vacuum sucking through the groove 2. A coat 3 for covering the chuck surface 1 is placed at a surface side for retaining the wafer, the material is TiC or TaC which are harder than the wafer, and the CVD method is used for formation. A coat layer is 10-60mum thick, coat thickness after grinding and lap is 5-30mum, and the surface is finished equally to or less than a wafer surface roughness. A base material 5 of the chuck is made of Al2O3 ceramic which is mainly in porous structure and the hardness is equal to or more that the wafer. A coat 7 may cover the entire surface of the chuck.</p> |
