Apparatus and method for measuring chuck attachment force

Abstract

An apparatus and method for measuring a chuck attachment force are provided. The apparatus is capable of measuring loads applied to a measurement substrate, while the measurement substrate is detached from a chuck, and precisely calculating necessary force through a process of comparing and analyzing values of the measured loads. This may prevent errors in the application of attachment force during a semiconductor manufacturing process. In the semiconductor manufacturing process, when the substrate is detached from a chuck, the substrate may be prevented from being deformed or cracked.

1 . An apparatus for measuring a chuck attachment force, comprising:
 a chuck configured to receive and attach a substrate thereto;   a separating device that detaches the substrate from the chuck;   a variable load applying device connected to the separating device, the variable load applying device operating the separating device by changing a load of the variable load applying device; and   a controller that measures both a load of the variable load applying device when the substrate is attached to or contacts the separating device and a load of the variable load applying device when the substrate is detached from the chuck, to calculate a chuck attachment force.   
   
   
       2 . The apparatus of  claim 1 , wherein the separating device comprises:
 a vacuum device that creates a vacuum to adsorb the substrate; and   a drive device that transmits power to move the vacuum device.   
   
   
       3 . The apparatus of  claim 2 , wherein the drive device comprises a power transmitting device that connects the variable load applying device to the vacuum device to move the vacuum device. 
   
   
       4 . The apparatus of  claim 3 , wherein the power transmitting device comprises at least one pulley and at least one power transmitting member coupled to the at least one pulley. 
   
   
       5 . The apparatus of  claim 4 , wherein the at least one power transmitting member comprises of a wire or chain. 
   
   
       6 . The apparatus of  claim 2 , wherein the vacuum device comprises:
 at least one vacuum suction member that adsorbs the substrate; and   a vacuum pump to draw air through the at least one vacuum suction member.   
   
   
       7 . The apparatus of  claim 6 , wherein the at least one vacuum suction member comprises one selected from a vacuum suction pad or a vacuum suction pin. 
   
   
       8 . The apparatus of  claim 1 , further comprising:
 at least one sensor provided in or on the chuck to detect whether the substrate is attached to or detached from the chuck.   
   
   
       9 . The apparatus of  claim 8 , wherein at least one sensor comprises one selected from a pressure sensor, a magnetic sensor, or an optical sensor. 
   
   
       10 . The apparatus of  claim 1 , wherein the separating device comprises:
 a lift device that detaches the substrate from the chuck; and   a drive device that transmits drive force to move the lift device.   
   
   
       11 . The apparatus of  claim 10 , wherein the lift device comprises at least one lift pin that contacts the substrate to transmit the force applied from the drive device to the substrate. 
   
   
       12 . The apparatus of  claim 11 , further comprising:
 a lift plate that supports the at least one lift pin and a lift shaft that supports the lift plate.   
   
   
       13 . The apparatus of  claim 11 , further comprising:
 a contact detecting sensor provided in the at least one lift pin that contacts the substrate to detect whether the at least one lift pin contacts the substrate.   
   
   
       14 . The apparatus of  claim 10 , wherein the drive device comprises a power transmitting device that connects the variable load applying device to the lift device to transmit the drive force to the lift device. 
   
   
       15 . The apparatus of  claim 14 , wherein the power transmitting device comprises at least one pulley and at least one power transmitting member coupled to the at least one pulley. 
   
   
       16 . The apparatus of  claim 15 , wherein the at least one power transmitting member comprises of a wire or chain. 
   
   
       17 . The apparatus of  claim 1 , wherein the chuck comprises an electrostatic chuck and the apparatus measures electrostatic force. 
   
   
       18 . A method of measuring a chuck attachment force, comprising:
 placing a substrate onto a chuck;   attaching the substrate to the chuck using an attachment force;   moving a separating device by changing a load of a variable load applying device to detach the substrate from the chuck;   measuring a load of the variable load applying device when the substrate is detached from the chuck; and   calculating a difference value between the load of the variable load applying device measured when the substrate is detached from the chuck and a load of the variable load applying device measured when the separating device is attached to or contacts the substrate, and determining a chuck attachment force using the difference value.   
   
   
       19 . The method of  claim 18 , wherein the chuck comprises an electrostatic chuck and the attachment force comprises an electrostatic force. 
   
   
       20 . The method of  claim 18 , wherein the separating device comprises a vacuum device, wherein the moving step comprises moving the vacuum device upwards by changing the load of the variable load applying device to detach the substrate from the chuck, and wherein the calculating step comprises calculating a difference value between the load of the variable load applying device measured when the substrate is detached from the chuck and a load of the variable load applying device measured when the vacuum device is attached to the substrate, and determining the chuck attachment force using the difference value. 
   
   
       21 . The method of  claim 20 , wherein the chuck comprises an electrostatic chuck and the attachment force comprises an electrostatic force. 
   
   
       22 . The method of  claim 18 , wherein the separating device comprises a lift device, wherein the moving step comprises moving the lift device upwards to detach the substrate from the chuck, and wherein the calculating step comprises calculating a difference value between the load of the variable load applying device measured when the lift device comes into contact with the substrate and the load of the variable load applying device measured when the substrate is detached from the chuck, and determining the chuck attachment force using the difference value. 
   
   
       23 . The method of  claim 22 , wherein the chuck comprises an electrostatic chuck and the attachment force comprises an electrostatic force. 
   
   
       24 . An apparatus for measuring a chuck attachment force, comprising:
 a chuck configured to receive and attach a substrate thereto;   a separating device, comprising a lift device that detaches a substrate from the chuck and a drive device that operates the lift device; and   a load measuring apparatus that measures a first load of the lift device before the separating device contacts the substrate and that measures a second load of the lift device when the substrate is detached from the chuck, the load measuring device calculating an attachment force of the chuck using a difference value between the first load and the second load.   
   
   
       25 . The apparatus of  claim 24 , further comprising:
 a support device that supports the chuck.   
   
   
       26 . The apparatus of  claim 25 , wherein the support device comprises a stage onto which the chuck is placed and a support frame that supports the stage. 
   
   
       27 . The apparatus of  claim 26 , wherein the lift device comprises:
 at least one lift pin that vertically moves through at least one corresponding opening provided in the chuck; and   a lift plate that supports the at least one lift pin.   
   
   
       28 . The apparatus of  claim 27 , further comprising:
 at least one sensor provided on or in the support device that detects whether the substrate is attached to or detached from the chuck and whether the at least one lift pin come into contact with the substrate.   
   
   
       29 . The apparatus of  claim 28 , further comprising:
 at least one guide bar provided on the stage such that the at least one lift plate is slidably coupled to the guide bar, wherein the at least one guide bar guides vertical movement of the lift device.   
   
   
       30 . The apparatus of  claim 27 , wherein the drive device comprises:
 a lift screw that supports the lift plate, the lift screw being vertically movable; and   a power generating and transmitting device that rotates the lift screw.   
   
   
       31 . The apparatus of  claim 24 , wherein the load measuring apparatus comprises:
 a load measuring device that measures the first load and the second load;   a memory that stores a value of the first load value and the second load therein;   an arithmetic device that calculates a difference value between the first load value and the second load value; and   a display device that displays the difference value.   
   
   
       32 . The apparatus of  claim 24 , wherein the chuck comprises an electrostatic chuck and the apparatus measures electrostatic force. 
   
   
       33 . A method of measuring chuck attachment force, comprising:
 placing a substrate on a chuck;   attaching the substrate to the chuck using an attachment force;   moving a lift device to detach the substrate from the chuck;   measuring a first load of the lift device before the lift device contacts the substrate attached to the chuck;   measuring a second load of the lift device when the substrate is detached from the chuck; and   calculating a chuck attachment force using the measured first and second loads.   
   
   
       34 . The method of  claim 33 , further comprising:
 attaching the substrate to the chuck using an electrostatic force generated by applying power to the chuck, before measuring the first load.   
   
   
       35 . The method of  claim 34 , further comprising:
 determining an electrostatic force using a difference value between the first load and the second load.   
   
   
       36 . The method of  claim 33 , wherein the chuck comprises an electrostatic chuck and the method measures electrostatic force