Wafer holder, heater unit having the wafer holder, and wafer prober having the heater unit

Abstract

A wafer holder hardly deformable under high load and capable of effectively preventing a contact failure with a wafer and further capable of preventing temperature increase of a driving system of a wafer prober is provided. In a wafer holder having a chuck top and a supporter, variation in thickness of the chuck top from a wafer-mounting surface to a contact surface with the supporter, and variation in thickness of the supporter from a bottom surface to a contact surface with the chuck top are both set to at most 50 μm. When the supporter is of a structure having a circular tube portion and a base portion separate from each other, variation in thickness of the circular tube portion from a contact surface with the chuck top to a contact surface with the base portion, and variation in thickness of the base portion from a bottom surface to a contact surface with the circular tube portion are preferably both set to at most 25 μm.

1 . A wafer holder having a chuck top mounting and fixing a wafer on a wafer-mounting surface, and a supporter supporting said chuck top, wherein variation in thickness of said chuck top from said wafer-mounting surface to a contact surface with said supporter is at most 50 μm, and variation in thickness of said supporter from a bottom surface to a contact surface with said chuck top is at most 50 μm.  
   
   
       2 . The wafer holder according to  claim 1 , wherein said supporter has a structure including a circular tube portion in contact with said chuck top and a base portion supporting said circular tube portion, with said circular tube portion and said base portion separated, and variation in thickness of said circular tube portion from a contact surface with said chuck top to a contact surface with said base portion is at most 25 μm, and variation in thickness of said base portion from a bottom surface to a contact surface with said circular tube portion is at most 25 μm.  
   
   
       3 . The wafer holder according to  claim 1 , wherein variation in thickness of said chuck top from said wafer-mounting surface to the contact surface with said supporter, variation in thickness of said supporter from the bottom surface to the contact surface with said chuck top, variation in thickness of said circular tube portion from the contact surface with said chuck top to the contact surface with said base portion, and variation in thickness of said base portion from the bottom surface to the contact surface with said circular tube portion are at most 10 μm.  
   
   
       4 . The wafer holder according to  claim 1 , wherein ratio of the maximum diameter to the maximum thickness of said chuck top is at least 5 and at most 100.  
   
   
       5 . The wafer holder according to  claim 1 , wherein ratio of the maximum diameter to the maximum thickness of said chuck top is at least 10 and at most 50.  
   
   
       6 . The wafer holder according to  claim 1 , wherein material of said chuck top is a composite of metal and ceramics.  
   
   
       7 . The wafer holder according to  claim 1 , wherein material of said chuck top is a composite of aluminum and silicon carbide, or a composite of silicon and silicon carbide.  
   
   
       8 . The wafer holder according to  claim 1 , wherein material of said chuck top is ceramics.  
   
   
       9 . The wafer holder according to  claim 1 , wherein material of said supporter is ceramics or a composite of two or more ceramics.  
   
   
       10 . The wafer holder according to  claim 9 , wherein material of said supporter is any of alumina, silicon nitride, mullite, and a composite of alumina and mullite.  
   
   
       11 . The wafer holder according to  claim 1 , wherein said supporter is formed of a circular tube portion in contact with said chuck top and a base portion supporting said circular tube portion, thickness of said circular tube portion is at least 0.1 and at most 5.0 with thickness of said chuck top being 1.0, and thickness of said base portion is at least 0.5 and at most 10.0 with thickness of said chuck top being 1.0.  
   
   
       12 . The wafer holder according to  claim 1 , wherein said circular tube portion and said base portion are formed integrally.  
   
   
       13 . The wafer holder according to  claim 1 , having a pillar between said circular tube portion and said base portion or between said circular tube portion and said chuck top, and a sum of thickness of said pillar and said circular tube portion is at least 0.1 and at most 5.0 with thickness of said chuck top being 1.0.  
   
   
       14 . A wafer holder having a chuck top mounting and fixing a wafer on a wafer-mounting surface, and a supporter supporting said chuck top, wherein ratio of the maximum diameter to the maximum thickness of said chuck top is at least 5 and at most 100.  
   
   
       15 . The wafer holder according to  claim 14 , wherein ratio of the maximum diameter to the maximum thickness of said chuck top is at least 10 and at most 50.  
   
   
       16 . The wafer holder according to  claim 14 , wherein material of said chuck top is a composite of metal and ceramics.  
   
   
       17 . The wafer holder according to  claim 14 , wherein material of said chuck top is a composite of aluminum and silicon carbide, or a composite of silicon and silicon carbide.  
   
   
       18 . The wafer holder according to  claim 14 , wherein material of said chuck top is ceramics.  
   
   
       19 . The wafer holder according to  claim 14 , wherein material of said supporter is ceramics or a composite of two or more ceramics.  
   
   
       20 . The wafer holder according to  claim 19 , wherein material of said supporter is any of alumina, silicon nitride, mullite, and a composite of alumina and mullite.  
   
   
       21 . A wafer holder having a chuck top mounting and fixing a wafer on a wafer-mounting surface, and a supporter supporting said chuck top, wherein said supporter is formed of a circular tube portion in contact with said chuck top and a base portion supporting said circular tube portion, thickness of said circular tube portion is at least 0.1 and at most 5.0 with thickness of said chuck top being 1.0, and thickness of said base portion is at least 0.5 and at most 10.0 with thickness of said chuck top being 1.0.  
   
   
       22 . The wafer holder according to  claim 21 , wherein said circular tube portion and said base portion are formed integrally.  
   
   
       23 . The wafer holder according to  claim 21 , having a pillar between said circular tube portion and said base portion or between said circular tube portion and said chuck top, and a sum of thickness of said pillar and said circular tube portion is at least 0.1 and at most 5.0 with thickness of said chuck top being 1.0.  
   
   
       24 . A heater unit for a wafer prober, comprising the wafer holder according to  claim 1 .  
   
   
       25 . A heater unit for a wafer prober, comprising the wafer holder according to  claim 14 .  
   
   
       26 . A heater unit for a wafer prober, comprising the wafer holder according to  claim 21 .  
   
   
       27 . A wafer prober, comprising the heater unit according to  claim 1 .  
   
   
       28 . A wafer prober, comprising the heater unit according to  claim 14 .  
   
   
       29 . A wafer prober, comprising the heater unit according to  claim 21.