Load-lock apparatus and substrate cooling method

Abstract

A load-lock apparatus includes a vessel arranged to change a pressure between a pressure corresponding to the vacuum chamber and the atmospheric pressure, a pressure adjusting mechanism which adjusts a pressure in the vessel to a pressure corresponding to the vacuum chamber and the atmospheric pressure, a cooling member having a cooling mechanism and arranged in the vessel to cool a substrate by having the substrate placed on or in proximity to the cooling member, a substrate deformation detection unit for detecting deformation of the substrate in the vessel, and a controller which reduces a cooling rate of the substrate when the substrate deformation is detected during a substrate cooling period until the vessel is adjusted to have the atmospheric pressure after the vessel is adjusted to have a pressure corresponding to the vacuum chamber and a high temperature substrate is loaded into the vessel from the vacuum chamber.

1 . A load-lock apparatus for use in transferring a substrate from the atmospheric atmosphere to a vacuum chamber maintained in a vacuum and transferring a substrate having a high temperature from the vacuum chamber to the atmospheric atmosphere, the load-lock apparatus comprising:
 a vessel arranged to change a pressure between a pressure corresponding to the vacuum chamber and the atmospheric pressure;   a pressure adjusting mechanism which adjusts a pressure in the vessel to a pressure corresponding to the vacuum chamber when the vessel communicates with the vacuum chamber, and adjusts a pressure in the vessel to the atmospheric pressure when the vessel communicates with a space having the atmospheric atmosphere;   a cooling member having a cooling mechanism and arranged in the vessel to cool a substrate by having the substrate placed on or in proximity to the cooling member;   a substrate deformation detection unit for detecting deformation of the substrate in the vessel; and   a controller which reduces a cooling rate of the substrate when the substrate deformation detection unit detects deformation of the substrate that is equal to or larger than a predetermined value during a substrate cooling period until the vessel is adjusted to have the atmospheric pressure after the vessel is adjusted to have a pressure corresponding to the vacuum chamber and the substrate having the high temperature is loaded into the vessel from the vacuum chamber.   
     
     
         2 . The load-lock apparatus of  claim 1 , wherein the controller reduces the cooling rate by stopping increasing or reducing a pressure in the vessel when the substrate deformation detection unit detects the deformation of the substrate that is equal to or larger than the predetermined value while increasing the pressure in the vessel by the pressure adjusting mechanism. 
     
     
         3 . The load-lock apparatus of  claim 2 , wherein the controller resumes an increase in pressure in the vessel when the substrate deformation detection unit detects that the deformation of the substrate becomes smaller than the predetermined value after the controller reduced the cooling rate. 
     
     
         4 . The load-lock apparatus of  claim 1 , further comprising:
 wafer supporting pins which are provided to be protruded from and retracted into the cooling member, receive the substrate while being protruded from the cooling member, and descend with the substrate placed thereon such that the substrate is placed on or in proximity to the cooling member,   wherein when the substrate deformation detection unit detects the deformation of the substrate that is equal to or larger than the predetermined value, the controller reduces the cooling rate by raising the wafer supporting pins or stopping descending of the wafer supporting pins if the wafer supporting pins descend with the substrate placed thereon.   
     
     
         5 . The load-lock apparatus of  claim 4 , wherein when the substrate deformation detection unit detects that the deformation of the substrate becomes smaller than the predetermined value after the controller reduced the cooling rate, the controller restores the wafer supporting pins to their original positions or resumes descending of the wafer supporting pins if the descending of the wafer supporting pins was stopped. 
     
     
         6 . The load-lock apparatus of  claim 1 , wherein the substrate deformation detection unit includes a first sensor for measuring a displacement of a central portion of the substrate and a second sensor for measuring a displacement of an edge portion of the substrate, and detects deformation of the substrate based on a difference between the detection value of the first sensor and the detection value of the second sensor. 
     
     
         7 . The load-lock apparatus of  claim 6 , wherein the first sensor and the second sensor are laser displacement sensors. 
     
     
         8 . The load-lock apparatus of  claim 1 , wherein the vacuum chamber is a transfer chamber including a transfer unit for transferring the substrate to a vacuum processing chamber that performs a high temperature process on the substrate in a vacuum, and a high temperature substrate is transferred to the vessel through the vacuum chamber after the high temperature process has been performed on the substrate in the vacuum processing chamber. 
     
     
         9 . A substrate cooling method for use in a load-lock apparatus for use in transferring a substrate from the atmospheric atmosphere to a vacuum chamber maintained in a vacuum and transferring a substrate having a high temperature from the vacuum chamber to the atmospheric atmosphere, the load-lock apparatus including a vessel arranged to change a pressure between a pressure corresponding to the vacuum chamber and the atmospheric pressure, a pressure adjusting mechanism which adjusts a pressure in the vessel to a pressure corresponding to the vacuum chamber when the vessel communicates with the vacuum chamber, and adjusts a pressure in the vessel to the atmospheric pressure when the vessel communicates with a space having the atmospheric atmosphere, and a cooling member having a cooling mechanism and arranged in the vessel to cool a substrate by having the substrate placed on or in proximity to the cooling member, the method comprising:
 detecting deformation of the substrate in the vessel during a substrate cooling period until the vessel is adjusted to have the atmospheric pressure after the vessel is adjusted to have a pressure corresponding to the vacuum chamber and the substrate having the high temperature is loaded into the vessel from the vacuum chamber; and 
 reducing a cooling rate of the substrate when the deformation of the substrate that is equal to or larger than a predetermined value is detected. 
 
     
     
         10 . The method of  claim 9 , wherein the cooling rate is reduced by stopping increasing or reducing a pressure in the vessel when the deformation of the substrate that is equal to or larger than the predetermined value is detected by the pressure adjusting mechanism while increasing the pressure in the vessel. 
     
     
         11 . The method of  claim 10 , wherein an increase in pressure in the vessel is resumed when it is detected that the deformation of the substrate becomes smaller than the predetermined value after the cooling rate was reduced. 
     
     
         12 . The method of  claim 9 , wherein the load-lock apparatus further includes wafer supporting pins which are provided to be protruded from and retracted into the cooling member, receive the substrate while being protruded from the cooling member, and descend with the substrate placed thereon such that the substrate is placed on or in proximity to the cooling member, and
 wherein when the deformation of the substrate that is equal to or larger than the predetermined value is detected, the cooling rate is reduced by raising the wafer supporting pins or stopping descending of the wafer supporting pins if the wafer supporting pins descend with the substrate placed thereon.   
     
     
         13 . The method of  claim 12 , wherein when it is detected that the deformation of the substrate becomes smaller than the predetermined value after the cooling rate was reduced, the wafer supporting pins are restored to their original positions or descending of the wafer supporting pins is resumed if the descending of the wafer supporting pins was stopped.