Ceramic substrate for semiconductor fabricating device

Abstract

The objective of the invention is to provide a ceramic substrate: wherein even if rapid temperature rising or rapid temperature falling is conducted, no problem of cracking or warp of the ceramic substrate occurs; wherein, in case that the ceramic substrate is a ceramic substrate constituting an electrostatic chuck, local dispersion of chuck power is eliminated, in case that the ceramic substrate is a ceramic substrate constituting a hot plate, local dispersion of temperature of a wafer treating face is eliminated, in case that the ceramic substrate is a ceramic substrate constituting a wafer prober, dispersion of applied voltage of a guard electrode or a ground electrode is eliminated and a stray capacitor or noise can be eliminated. The ceramic substrate of the present invention is a ceramic substrate provided with a conductor layer on the surface of the ceramic substrate or inside the ceramic substrate, wherein: the ratio (t 2 /t 1 ) of the average thickness of the conductor layer (t 2 ) to the average thickness of the ceramic substrate (t 1 ) is less than 0.1 and; a dispersion of the thickness of the conductor layer to the average thickness of the conductor layer is in a range of −70 to +150%.

1 . A ceramic substrate provided with a conductor layer on the surface of said ceramic substrate or inside said ceramic substrate, 
 wherein: the ratio (t 2/t   1 ) of the average thickness of said conductor layer (t 2 ) to the average thickness of said ceramic substrate (t 1 ) is less than 0.1; and a dispersion of the thickness of the conductor layer to the average thickness of the conductor layer is in a range of −70 to +150%.    
     
     
         2 . The ceramic substrate according to  claim 1 , 
 wherein said ceramic substrate is in a disc-shape with a diameter exceeding 150 mm.    
     
     
         3 . The ceramic substrate according to  claim 1  or  2 , 
 wherein the thickness of said ceramic substrate is 25 mm or less.  
 
     
     
         4 . The ceramic substrate according to any of  claims 1  to  3 , 
 wherein said conductor layer is an electrostatic electrode.  
 
     
     
         5 . The ceramic substrate according to any of  claims 1  to  3 , 
 wherein said conductor layer is a resistance heating element.  
 
     
     
         6 . The ceramic substrate according to any of  claims 1  to  3 , 
 wherein said conductor layer is any of a chuck top electrode, a guard electrode and a ground electrode.