Reciprocating megasonic probe

Abstract

A method of cleaning a substrate comprises placing the substrate on a rotating fixture, placing a liquid on at least one side of the substrate, and creating a standing wave of megasonic energy oriented generally parallel to the substrate. The standing wave generates an associated pattern of high-agitation regions in the liquid. The method further comprises moving the standing wave back-and-forth so as to move the pattern of high-agitation regions about with respect to the substrate. An apparatus for cleaning substrates comprises a support to rotate the substrate about a first axis, and a transmitter extending generally parallel to a surface of the substrate. The apparatus further comprises a megasonic transducer in acoustically coupled relation to the transmitter, and a reciprocation drive in fixed relation to the transmitter. The reciprocation drive moves the transmitter back-and-forth within a plane generally parallel to the surface of the substrate.

1 . An apparatus for cleaning substrates, said apparatus comprising: 
 a rotary support which is adapted to support and rotate said substrate about a first axis;    a transmitter extending generally parallel to a surface of said substrate;    a megasonic transducer in acoustically coupled relation to said transmitter; and    a reciprocation drive in fixed relation to said transmitter, said reciprocation drive moving said transmitter back-and-forth within a plane generally parallel to said surface of said substrate.    
     
     
         2 . The apparatus of  claim 1 , wherein said reciprocation drive causes substantially linear back-and-forth movement of said transmitter.  
     
     
         3 . The apparatus of  claim 1 , wherein said megasonic transducer generates a standing wave of megasonic energy in said transmitter and said reciprocation drive alternately: (a) displaces said standing wave in a substantially linear fashion, by a distance of about 0.5 to 2 times the wavelength of said standing wave, in a first direction; and (b) displaces said standing wave in a substantially linear fashion, by substantially the same distance, in the opposite direction.  
     
     
         4 . The apparatus of  claim 1 , wherein said reciprocation drive causes substantially linear back-and-forth movement of said transmitter, at a frequency of about 0.1 to 2 cycles per second.  
     
     
         5 . The apparatus of  claim 1 , wherein said reciprocation drive causes substantially angular back-and-forth movement of said transmitter.  
     
     
         6 . The apparatus of  claim 1 , wherein said reciprocation drive causes substantially angular back-and-forth movement of said transmitter, at a frequency of about 0.1 to 2 cycles per second.  
     
     
         7 . The apparatus of  claim 1 , further comprising a dispenser that dispenses liquid onto said surface of said substrate, wherein said megasonic transducer generates a standing wave of megasonic energy in said probe and an associated pattern of high-agitation regions in said liquid, and wherein said reciprocation drive moves said pattern of high-agitation regions about with respect to said surface of said substrate.  
     
     
         8 . In a substrate cleaner having a transmitter extending generally parallel to and close to a surface of a rotating substrate, said transmitter agitating a liquid on a surface of said substrate, the improvement comprising: a reciprocation drive operatively connected to said transmitter, said reciprocation drive causing back-and-forth movement of said transmitter and corresponding back-and-forth movement of a pattern of high-agitation regions formed in said liquid by said transmitter.  
     
     
         9 . The cleaner of  claim 8 , wherein said reciprocation drive comprises a linear reciprocation drive and said reciprocation drive causes substantially linear back-and-forth movement of said transmitter and said pattern of high-agitation regions, with a frequency of about 0.1 to 2 cycles per second.  
     
     
         10 . A method of cleaning a substrate, the method comprising: placing said substrate on a rotating fixture; applying a liquid to at least one side of said substrate; creating a wave of megasonic energy oriented generally parallel to said substrate, said wave generating high-agitation regions in said liquid; and moving said high-agitation regions about with respect to said substrate.