Freeze cleaning apparatus

Abstract

A freeze cleaning apparatus includes a table for supporting a processing target substrate having a first surface and a second surface opposite to the first surface, a liquid supply unit positioned to supply a cleaning liquid onto the second surface of the processing target substrate that is placed such that the first surface faces the table, and a cooling gas discharge unit in the table to supply a cooling gas to the first surface side of the processing target substrate. A gap between the table and the processing target substrate is set such that the cooling gas flows as a laminar flow between the table and the processing target substrate.

What is claimed is: 
     
         1 . A freeze cleaning apparatus comprising:
 a table for supporting a processing target substrate having a first surface and a second surface opposite to the first surface;   a liquid supply unit positioned to supply a cleaning liquid onto the second surface of the processing target substrate that is placed such that the first surface faces the table; and   a cooling gas discharge unit in the table to supply a cooling gas to the first surface side of the processing target substrate,   wherein a gap between the table and the processing target substrate is set such that the cooling gas flows as a laminar flow between the table and the processing target substrate.   
     
     
         2 . The freeze cleaning apparatus according to  claim 1 , wherein the table includes a discharge port for the cooling gas and a groove provided on a surface facing the processing target substrate,
 the groove extends from the discharge port towards an outer edge of the table, and   a distance from the discharge port to the outer edge along the groove is longer than a linear distance between the discharge port and the outer edge.   
     
     
         3 . The freeze cleaning apparatus according to  claim 2 , wherein the groove terminates at a location within the outer edge of the table. 
     
     
         4 . The freeze cleaning apparatus according to  claim 2 , further comprising:
 a sensor that detects a temperature of the cleaning liquid on the processing target substrate;   a flow rate adjusting unit that adjusts a flow rate of the cooling gas; and   a controller that controls the flow rate adjusting unit based on the temperature detected by the sensor.   
     
     
         5 . The freeze cleaning apparatus according to  claim 4 , wherein the controller stops supply of the cooling gas and starts thawing the cleaning liquid based on the temperature detected by the sensor. 
     
     
         6 . The freeze cleaning apparatus according to  claim 1 , further comprising:
 a sensor that detects a temperature of the cleaning liquid on the processing target substrate;   a flow rate adjusting unit that adjusts a flow rate of the cooling gas; and   a controller that controls the flow rate adjusting unit based on the temperature detected by the sensor.   
     
     
         7 . The freeze cleaning apparatus according to  claim 5 , wherein the controller stops supply of the cooling gas and starts thawing the cleaning liquid based on the temperature detected by the sensor. 
     
     
         8 . The freeze cleaning apparatus according to  claim 1 , wherein the table includes a drain at an outer edge thereof. 
     
     
         9 . The freeze cleaning apparatus according to  claim 8 , wherein a top surface of the table is sloped downward from a center thereof toward the drain. 
     
     
         10 . The freeze cleaning apparatus according to  claim 1 , where the table has a main surface and supports for the processing target, and the gap is set by the supports positioning the processing target away from the main surface. 
     
     
         11 . A freeze cleaning apparatus comprising:
 a table that faces a first surface of a processing target substrate, the processing target having a second surface opposite to the first surface;   a liquid supply unit that supplies a cleaning liquid onto the second surface of the processing target substrate placed such that the first surface faces the table;   a side wall that surrounds a space between the processing target substrate and the table;   a cooling gas discharge unit that is provided in the table to discharge a cooling gas into the space; and   a drain that discharges the cooling gas from the space to the outside,   wherein the space between the processing target substrate and the table is a closed space.   
     
     
         12 . The freeze cleaning apparatus according to  claim 11 , wherein a top surface of the table is sloped downward from a center thereof toward the drain. 
     
     
         13 . The freeze cleaning apparatus according to  claim 11 , further comprising:
 a sensor that detects a temperature of the cleaning liquid on the processing target substrate;   a flow rate adjusting unit that adjusts a flow rate of the cooling gas; and   a controller that controls the flow rate adjusting unit based on the temperature detected by the sensor.   
     
     
         14 . The freeze cleaning apparatus according to claim  13 , wherein the controller stops supply of the cooling gas and starts thawing the cleaning liquid based on the temperature detected by the sensor. 
     
     
         15 . A freeze cleaning method comprising:
 a first process of forming a liquid film on a second surface of a processing target substrate having a first surface opposite to the second surface;   a second process of supplying a cooling gas to the first surface of the processing target substrate to solidify the liquid film; and   a third process of melting the liquid film and removing the liquid film from the second surface,   wherein the first to third processes are repeated, and   the repetition is terminated based on a temperature fluctuation of the liquid film in repetitive cycles of the first to third processes or a change in the lowest attainable temperature for each of the repetitive cycles.   
     
     
         16 . The freeze cleaning method of  claim 15 , wherein the processing target substrate is set above a table, and wherein a gap between the table and the processing target substrate is set such that the cooling gas flows as a laminar flow between the table and the processing target substrate. 
     
     
         17 . The freeze cleaning method of  claim 16 , wherein a top surface of the table is sloped downward from a center thereof toward the drain. 
     
     
         18 . The freeze cleaning method of  claim 15 , wherein the processing target substrate is surrounded by a wall and a top surface of a table to define a space between the processing target substrate and the table. 
     
     
         19 . The freeze cleaning method of  claim 18 , wherein the table includes a drain that discharges the cooling gas from the space to the outside. 
     
     
         20 . The freeze cleaning method of  claim 19 , wherein the top surface of the table is sloped downward from a center thereof toward the drain.