Semiconductor wafer cleaning system and method

Abstract

A method of and system for cleaning semiconductor wafers minimizes the exposure of the wafers to the air by washing, rinsing and drying the wafers in one cleaning chamber. The system includes a wafer support by which a plurality of wafers can be supported in the cleaning chamber as oriented vertically and spaced from each other, and tubular de-ionized water supply nozzles extending longitudinally in the direction in which the wafers are spaced from each other as disposed to the sides of the wafers. Each de-ionized water supply nozzle has an inner nozzle passageway, and a plurality of sets of nozzle holes extending radially through the main body of the nozzle from the inner nozzle passageway. Each such set of nozzle holes subtends an angle of 80˜100° in a vertical plane and is directed towards a surface of a respective wafer W. During a primary rinse procedure, the de-ionized water is supplied to the de-ionized water spray nozzles, and the liquid in the cleaning chamber is simultaneously discharged from a lower part of the chamber and by being allowed to overflow the chamber. The supplying of the de-ionized water to the de-ionized water spray nozzles and the discharging of the cleaning chamber are carried out in proportions that minimize differences in the etching rate of a wafer across the surface thereof.

1 . A method of cleaning semiconductor wafers, comprising:
 filling a cleaning chamber with a cleaning solution;   washing a plurality of wafers by submerging the wafers in the cleaning solution within the cleaning chamber with the wafers being oriented vertically and spaced from each other in a first direction;   subsequently rinsing the vertically oriented wafers within the cleaning chamber by supplying de-ionized water to de-ionized water spray nozzles having nozzle holes directed towards respective vertically oriented surfaces of the wafer, and thereby spraying the de-ionized water into the cleaning chamber and onto the surfaces of the wafers within the chamber;   continuing the spraying of the de-ionized water into the cleaning chamber such that liquid in the cleaning chamber begins to overflow the cleaning chamber;   draining the liquid in the cleaning chamber from a lower part of the cleaning chamber as the de-ionized water is sprayed into the cleaning chamber, and the liquid overflows the cleaning chamber; and   controlling the supplying of the de-ionized water to the de-ionized water spray nozzles and said draining of said liquid such that liquid in an amount of 92-97 weight % of the de-ionized water that is being supplied by the nozzles into the cleaning chamber is simultaneously discharged from the cleaning chamber through the lower part of the cleaning chamber  30 , while liquid in an amount of 3-8 weight % of the de-ionized water that is being supplied by the nozzles is simultaneously discharged as overflowing the cleaning chamber, all while the wafers remain within the cleaning chamber.   
     
     
         2 . The method of  claim 1 , wherein said controlling the supplying of the de-ionized water to the de-ionized water spray nozzles comprises regulating the flow of de-ionized water through said nozzles to a rate of 21˜26 l/min. 
     
     
         3 . The method as claimed in  claim 1 , wherein said spraying of the de-ionized water into the cleaning chamber comprises spraying the water onto the surfaces of the over a range of 80˜100° in a vertical plane in which each of said surfaces lies. 
     
     
         4 . The method as claimed in  claim 2 , wherein said spraying of the de-ionized water into the cleaning chamber comprises spraying the water onto the surfaces of the over a range of 80˜100° in a vertical plane in which each of said surfaces lies. 
     
     
         5 . The method as claimed in  claim 1 , wherein said discharging of the de-ionized water form the lower part of the leaning chamber is carried out at least two locations aligned in said first direction in which the wafers W are spaced from each other.