Reciprocating megasonic probe
View Patent ↗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. 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;
positioning a transmitter generally parallel to and close to but spaced from said substrate with a megasonic transducer in acoustically coupled relation to said transmitter, said transmitter being in contact with said liquid applied to said at least one side of said substrate;
creating a standing wave of megasonic energy oriented generally parallel to said substrate with said transmitter, said standing wave generating an associated pattern of high-agitation regions in said liquid; and
creating relative back-and-forth movement between said standing wave and said substrate so as to move said pattern of high-agitation regions in a radial direction with respect to said substrate.
2. The method of claim 1 , wherein the step of creating a standing wave comprises creating said wave along a line generally parallel to a surface of said substrate.
3. The method of claim 1 , wherein the step of creating said relative back-and-forth movement comprises reciprocating said transmitter substantially linearly along its longitudinal axis.
4. The method of claim 1 , wherein the step of creating said relative back-and-forth movement comprises reciprocating said transmitter substantially linearly along a line generally perpendicular to its longitudinal axis.
5. The method of claim 1 wherein the step of creating said relative back-and-forth movement comprises reciprocating said transmitter substantially linearly along a line generally transverse to its longitudinal axis.
6. The method of claim 1 , wherein said substrate comprises a semiconductor wafer.
7. 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 standing wave of megasonic energy oriented generally parallel to said substrate, said standing wave generating an associated pattern of high-agitation regions in said liquid; and
creating relative back-and-forth movement between said standing wave and said substrate by reciprocating said standing wave in a substantially linear fashion so as to move said pattern of high-agitation regions in a radial direction with respect to said substrate.
8. The method of claim 7 wherein the step of creating said relative back-and-forth movement further comprises reciprocating said standing wave in a substantially linear fashion at a frequency of about 0.1 to 2 cycles per second.
9. 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 standing wave of megasonic energy oriented generally parallel to said substrate, said standing wave generating an associated pattern of high-agitation regions in said liquid; and
creating relative back-and-forth movement between said standing wave and said substrate so as to move said pattern of high-agitation regions in a radial direction with respect to said substrate;
wherein the step of creating relative back-and-forth movement comprises displacing 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 displacing said standing wave in a substantially linear fashion, by substantially the same distance, in the opposite direction.
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 standing wave of megasonic energy oriented generally parallel to said substrate, said standing wave generating an associated pattern of high-agitation regions in said liquid; and
creating relative back-and-forth movement between said standing wave and said substrate by reciprocating said standing wave substantially angularly so as to move said pattern of high-agitation regions with respect to said substrate.
11. The method of claim 10 , wherein the step of reciprocating said standing wave substantially angularly comprises reciprocating said standing wave substantially angularly at a frequency of about 0.1 to 2 cycles per second.
12. A method of cleaning a substrate, the method comprising:
placing said substrate on a rotating fixture;
placing a liquid on at least one side of said substrate;
positioning a transmitter generally parallel to and close to but spaced from said substrate with a megasonic transducer in acoustically coupled relation to said transmitter, said transmitter being in contact with said liquid applied to said at least one side of said substrate;
creating a standing wave of megasonic energy oriented generally parallel to said substrate with the transmitter, said standing wave generating an associated pattern of high-agitation regions in said liquid; and
a causing back-and-forth movement of said standing wave relative to said substrate or vice versa so as to move said pattern of high-agitation regions in a radial direction with respect to said substrate.
13. The method of claim 12 , wherein the step of creating a standing wave comprises creating said wave along a line generally parallel to a surface of said substrate.
14. A method of cleaning a substrate, the method comprising:
placing said substrate on a rotating fixture;
placing a liquid on at least one side of said substrate;
creating a standing wave of megasonic energy oriented generally parallel to said substrate, said standing wave generating an associated pattern of high-agitation regions in said liquid;
a causing back-and-forth movement of said standing wave relative to said substrate or vice versa so as to move said pattern of high-agitation regions in a radial direction about with respect to said substrate; and
wherein the step of causing back-and-forth movement of said standing wave relative to said substrate comprises: displacing 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 displacing said standing wave in a substantially liner fashion, by substantially the same distance, in the opposite direction.
15. The method of claim 12 , wherein the step of causing back-and-forth movement of said standing wave relative to said substrate comprises: displacing said substrate 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 displacing said substrate in a substantially linear fashion, by substantially the same distance, in the opposite direction.
16. The method of claim 14 , wherein the step of causing back-and-forth movement of said standing wave relative to said substrate further comprises reciprocating said standing wave in a substantially linear fashion at a frequency of about if 0.1 to 2 cycles per second.
17. The method of claim 15 , wherein the step of causing back-and-forth movement of said standing wave relative to said substrate further comprises reciprocating said substrate in a substantially linear fashion at a frequency of about 0.1 to 2 cycles per second.
18. The method of claim 12 , wherein said substrate comprises a semiconductor wafer.