Adaptive chuck for planar bonding between substrates

Abstract

An electrostatic chuck includes an array of independently biased conductive chuck elements, an array of sensor-conductor assemblies, and/or a combination of an array of sensor-conductor assemblies and at least one motorized chuck. Conductive chuck elements, either standing alone or embedded in a sensor-conductor assembly, are independently biased electrostatically to compensate for bowing and/or warping of a substrate thereupon so that the substrate can be bonded with a planar surface. A single electrostatic chuck can be employed to reduce the bowing and warping of one of the two substrates to be bonded, or two electrostatic chucks can be employed to minimize the bowing and warping of two substrates to be bonded.

1 . A method of processing at least one substrate, said method comprising:
 mapping vertical deviations of a surface of a substrate from a flat plane;   placing said substrate on an electrostatic chuck including an insulating chuck body and an array of conductive chuck elements embedded in said insulating chuck body; and   providing an electrostatic bias voltage to each of said conductive chuck elements, wherein said surface of said substrate is flattened by variations in electrostatic bias voltages applied to said array of conductive chuck elements.   
     
     
         2 . The method of  claim 1 , wherein said electrostatic chuck further comprises an array of commonly biased conductive chuck elements that receive a common voltage from a common voltage source, and said method further comprises providing another electrostatic bias voltage to said array of commonly biased conductive chuck elements. 
     
     
         3 . The method of  claim 1 , further comprising:
 placing a second substrate on a second electrostatic chuck; and   bonding said second substrate with said substrate by bringing said second substrate into physical contact with said substrate while said surface of substrate stays flattened by said variations in said electrostatic bias voltages.   
     
     
         4 . The method of  claim 3 , wherein said second electrostatic chuck includes a second insulating chuck body and a second array of second conductive chuck elements embedded in said second insulating chuck body, and said method further includes providing an electrostatic bias voltage to each of said second conductive chuck elements, wherein a surface of said second substrate is flattened by variations in electrostatic bias voltages applied to said second array of second conductive chuck elements during said bonding. 
     
     
         5 . A method of processing at least one substrate, said method comprising:
 placing a substrate on an electrostatic chuck including an insulating chuck body and an array of sensor-conductor assemblies embedded in said insulating chuck body, wherein each of said sensor-conductor assemblies includes a conductive chuck element, a sensor configured to detect a substrate upon contact, and a motor that moves said sensor vertically;   mapping vertical deviations of a surface of said substrate from a flat plane; and   providing an electrostatic bias voltage to each of said conductive chuck elements, wherein said surface of said substrate is flattened by variations in electrostatic bias voltages applied to said array of conductive chuck elements.   
     
     
         6 . The method of  claim 5 , wherein said electrostatic chuck further comprises at least one motorized conductive chuck element configured to move said substrate. 
     
     
         7 . The method of  claim 5 , further comprising:
 placing a second substrate on a second electrostatic chuck; and   bonding said second substrate with said substrate by bringing said second substrate into physical contact with said substrate while said surface of substrate stays flattened by said variations in said electrostatic bias voltages.   
     
     
         8 . The method of  claim 7 , wherein said second electrostatic chuck includes a second insulating chuck body and a second array of second sensor-conductor assemblies embedded in said second insulating chuck body, wherein each of said second sensor-conductor assemblies includes a second conductive chuck element, a second sensor configured to detect said second substrate upon contact, and a second motor that moves said second sensor vertically, wherein said method further comprises flattening a surface of said second substrate by applying different electrostatic bias voltages to said second conductive chuck elements during said bonding.