Wetting a workpiece surface in a fluid-processing system
View Patent ↗A method and apparatus for wetting the surface of a workpiece is disclosed. The apparatus includes a chamber with a vacuum port and a fluid port and a workpiece holder including a body, a ring, and a port. The body includes a surface and defines a cavity extending from the surface. The ring is adapted to retain the workpiece on the surface of body over the cavity. The ring forms a fluid seal relative to the workpiece and to the workpiece holder. The port is defined in the body and in communication with the cavity. The port affects pressure in the cavity to minimize a pressure differential between the front and back surfaces of the workpiece. The fluid port is in communication with the chamber. The fluid port delivers a fluid (e.g., a substantially degassed fluid) to wet the front surface of the workpiece during operation of the chamber at a reduced pressure relative to atmosphere.
1. An apparatus for wetting a workpiece having front and back surfaces, the apparatus comprising:
a chamber arranged to operate at a reduced pressure;
a workpiece holder disposed in the chamber, the workpiece holder comprising:
a body comprising a surface, the body defining a cavity extending from the surface;
a ring adapted to retain the workpiece on the surface of the body over the cavity, the ring forming a fluid seal relative to the workpiece and to the workpiece holder; and
a port defined in the body and in communication with the cavity, the port affecting pressure in the cavity to reduce a pressure differential between the front and back surfaces of the workpiece; and
a fluid port in communication with the chamber, the fluid port delivering a fluid to wet the front surface of the workpiece during operation of the chamber at a reduced pressure relative to atmosphere.
2. The apparatus of claim 1 wherein the chamber comprises a vent valve to return the chamber to atmospheric pressure.
3. The apparatus of claim 1 further comprising a fluid source containing the fluid coupled to the fluid port.
4. The apparatus of claim 1 wherein the fluid port is positioned in a bottom portion of the chamber.
5. The apparatus of claim 1 wherein the fluid comprises a substantially degassed fluid.
6. The apparatus of claim 1 wherein the fluid comprises deionized water.
7. The apparatus of claim 1 wherein the fluid comprises organic molecules.
8. The apparatus of claim 1 wherein the ring comprises contacts adapted for electrical communication with the workpiece.
9. The apparatus of claim 1 further comprising an electrode adapted to deliver an electric potential to or receive an electric potential from the workpiece while the workpiece is immersed in the fluid.
10. A method of wetting a workpiece having front and back surfaces, the method comprising:
retaining the workpiece on a surface of a workpiece holder disposed in a chamber to create fluid seals between a ring and the workpiece and between the ring and the workpiece holder; reducing pressure in the chamber relative to atmospheric pressure;
reducing a pressure differential between the front and back surfaces of the workpiece; and
introducing a fluid to the chamber to wet the front surface of the workpiece.
11. The method of claim 10 further comprising reducing surface tension between the surface of the workpiece and the fluid.
12. The method of claim 10 wherein wetting the workpiece comprises contacting features in the workpiece with the fluid to displace a gas or contaminant.
13. The method of claim 10 further comprising venting the chamber to atmospheric pressure after the workpiece is wet.
14. The method of claim 10 further comprising introducing the fluid from a bottom portion of the chamber.
15. The method of claim 10 wherein the fluid comprises a substantially degassed fluid.
16. The method of claim 10 wherein the substantially degassed fluid comprises deionized water.
17. The method of claim 10 wherein the substantially degassed fluid comprises organic molecules.
18. The method of claim 10 further comprising delivering an electric potential to or receiving an electric potential from the workpiece while the workpiece is immersed in the fluid.
19. An apparatus for wetting a workpiece having front and back surfaces, the apparatus comprising:
means for retaining the workpiece on a surface of a workpiece holder disposed in a chamber and for sealing the back surface of the workpiece from the chamber;
means for reducing pressure in the chamber relative to atmospheric pressure;
means for reducing a pressure differential between the front and back surfaces of the workpiece; and
means for introducing a fluid into the chamber to wet the front surface of the workpiece.
20. The apparatus of claim 19 , wherein the means for introducing introduces the fluid into the chamber while the chamber is at a reduced pressure relative to atmospheric pressure by the means for reducing pressure.