Substrate cleaning technique employing multi-phase solution

Abstract

Apparatus, methods, and computer programs for cleaning opposed surfaces of a semiconductor wafer are presented. One apparatus includes first, second, and third valves, and one or more second drains. The first valves are coupled to a supply of rinsing solution and to first throughways that are coupled to an immersion tank above a region in the immersion tank, the region being defined by an area occupied by the substrate when the substrate is disposed vertically on a support within the immersion tank. The second valves are coupled to first drains and to second throughways that are coupled to the immersion tank below the region, and the third valves are coupled to a supply of cleaning solution and to third throughways that are coupled to the immersion tank below the region. Further, the second drains are coupled to fourth throughways that are coupled to the immersion tank above the region.

What is claimed is: 
     
         1 . An apparatus for cleaning a substrate, the apparatus comprising:
 a plurality of first valves coupled to a supply of rinsing solution and to a plurality of first throughways that are coupled to an immersion tank above a region in the immersion tank, the region defined by an area occupied by the substrate when the substrate is disposed vertically on a support within the immersion tank;   one or more second valves coupled to one or more first drains and to one or more second throughways that are coupled to the immersion tank below the region;   a plurality of third valves coupled to a supply of cleaning solution and to a plurality of third throughways that are coupled to the immersion tank below the region; and   one or more second drains coupled to one or more fourth throughways that are coupled to the immersion tank above the region.   
     
     
         2 . The apparatus as recited in  claim 1 , wherein the plurality of first valves includes:
 a left first valve disposed to the left of the region; and   a right first valve disposed to the right of the region.   
     
     
         3 . The apparatus as recited in  claim 1 , wherein the plurality of third valves further includes:
 a left third valve disposed to the left of the region; and   a right third valve disposed to the right of the region.   
     
     
         4 . The apparatus as recited in  claim 1 , wherein the one or more second drains further include:
 a left second drain disposed to the left of the region; and   a right second drain disposed to the right of the region.   
     
     
         5 . The apparatus as recited in  claim 1 , wherein the one or more first drains include a bottom first drain, wherein a second throughway is disposed at a bottom of the immersion tank. 
     
     
         6 . The apparatus as recited in  claim 1 , further including:
 a plurality of fourth valves coupled to a second supply of rinsing solution and to the plurality of first throughways.   
     
     
         7 . The apparatus as recited in  claim 1 , further including:
 a plurality of fifth valves coupled to a third supply of rinsing solution and to the plurality of third throughways.   
     
     
         8 . The apparatus as recited in  claim 1 , further including:
 a pump coupled to the one or more second drains.   
     
     
         9 . The apparatus as recited in  claim 1 , wherein the rinsing solution is isopropyl alcohol. 
     
     
         10 . The apparatus as recited in  claim 1 , wherein the rinsing solution is de-ionized water. 
     
     
         11 . An apparatus for cleaning a substrate, the apparatus comprising:
 a plurality of first valves coupled to a supply of a first rinsing solution and to a plurality of first throughways that are coupled to an immersion tank above a region in the immersion tank, the region defined by an area occupied by the substrate when the substrate is disposed vertically on a support within the immersion tank;   a plurality of second valves coupled to one or more first drains and to a plurality of second throughways that are coupled to the immersion tank below the region;   a plurality of third valves coupled to a supply of cleaning solution and to a plurality of third throughways that are coupled to the immersion tank below the region; and   a plurality of fourth valves coupled to a supply of a second rinsing solution and to the plurality of first throughways;   a plurality of fifth valves coupled to a supply of a third rinsing solution and to the third throughways; and   one or more second drains coupled to fourth throughways that are coupled to the immersion tank above the region.   
     
     
         12 . The apparatus as recited in  claim 11 , wherein the plurality of first valves includes:
 a left first valve disposed to the left of the region; and   a right first valve disposed to the right of the region.   
     
     
         13 . The apparatus as recited in  claim 11 , wherein the plurality of third valves further includes:
 a left third valve disposed to the left of the region; and   a right third valve disposed to the right of the region.   
     
     
         14 . The apparatus as recited in  claim 11 , wherein the one or more second drains further include:
 a left second drain disposed to the left of the region; and   a right second drain disposed to the right of the region.   
     
     
         15 . The apparatus as recited in  claim 11 , further including:
 a pump coupled to the one or more second drains.   
     
     
         16 . A method for cleaning a substrate, the method comprising:
 placing the substrate on a support in an immersion tank without any solution in the immersion tank;   activating a plurality of first valves to provide a first flow of a rinsing solution to the immersion tank, the rinsing solution entering the immersion tank above the substrate;   activating a plurality of second valves after deactivating the plurality of first valves to drain the rinsing solution, the rinsing solution exiting the immersion tank below the substrate;   activating a plurality of third valves to provide a second flow of a cleaning solution to the immersion tank, the cleaning solution entering the immersion tank below the substrate; and   activating a pump to drain the cleaning solution, the cleaning solution exiting the immersion tank above the substrate.   
     
     
         17 . The method as recited in  claim 16 , wherein the first flow and the second flow move in opposite directions. 
     
     
         18 . The method as recited in  claim 16 , wherein the first flow moves in a direction of gravity. 
     
     
         19 . The method as recited in  claim 16 , wherein the second flow moves in a direction opposite of gravity. 
     
     
         20 . The method as recited in  claim 16 , wherein operations of the method are performed by a computer program when executed by one or more processors, the computer program being embedded in a non-transitory computer-readable storage medium.