Apparatus for treating a workpiece with steam and ozone
View Patent ↗In a method for processing a workpiece to remove material from a first surface of the workpiece, steam is introduced onto the first surface under conditions so that at least some of the steam condenses and forms a liquid boundary layer on the first surface. The condensing steam helps to maintain the first surface of the workpiece at an elevated temperature. Ozone is provided around the workpiece under conditions where the ozone diffuses through the boundary layer and reacts with the material on the first surface. The temperature of the first surface is controlled to maintain condensation of the steam.
1. An apparatus for processing a workpiece, comprising:
a process chamber;
a workpiece holder in the process chamber for holding the workpiece;
a steam generator connecting with the process chamber for delivering steam into the process chamber;
an ozone generator connecting with the process chamber for delivering ozone into the process chamber; and
a cooling fluid supply connecting with the process chamber for delivering a cooling fluid to a second side of the workpiece.
2. The apparatus of claim 1 wherein the cooling fluid is provided at a temperature lower than the temperature of the steam.
3. The apparatus of claim 1 wherein the process chamber is sealed to be pressure tight.
4. The apparatus of claim 1 wherein the steam generator is connected to the process chamber with a flow line including a filter.
5. The apparatus of claim 1 further comprising a plurality nozzles in the process chamber for spraying at least one of the steam, the ozone, and the cooling fluid toward the workpiece.
6. The apparatus of claim 1 wherein the cooling fluid supply delivers a cooling liquid into the processing chamber as a pulsed spray.
7. The apparatus of claim 1 wherein the steam generator provides steam into the process chamber along with at least one of a surfactant, ammonium hydroxide, an acid hydroxide, sulfuric acid, hydrochloric acid, and de-ionized water.
8. The apparatus of claim 1 further comprising a means for controlling a thickness of a layer of liquid formed on the first side of the workpiece.
9. The apparatus of claim 1 wherein the workpiece holder comprises a rotor which spins within the process chamber.
10. The apparatus of claim 1 wherein the cooling liquid is at a temperature of 75° C. to 95° C.
11. The apparatus of claim 1 further comprising a steam flow line leading from the steam generator into the process chamber, and an ozone flow line leading from the ozone generator directly or indirectly into the steam flow line, for mixing the ozone with the steam before the ozone and the steam are supplied into the process chamber.
12. The apparatus of claim 1 wherein the workpiece holder holds the workpiece in a vertical orientation.
13. An apparatus for processing a workpiece, comprising:
a process chamber;
a workpiece holder in the process chamber for holding the workpiece;
a steam generator connecting into the process chamber for delivering steam into the process chamber;
an ozone generator connecting into the process chamber for delivering ozone into the process chamber; and
a heat sink in contact with a second side of the workpiece for maintaining the workpiece at a temperature lower than the temperature of the steam.
14. The apparatus of claim 13 wherein the heat sink comprises a plate temperature-controlled via a cooling coil.
15. The apparatus of claim 13 wherein the heat sink comprises a plate temperature-controlled via a heat exchanger.
16. The apparatus of claim 13 further comprising means for controlling a thickness of a layer of condensate liquid formed on the first side of the workpiece.
17. The apparatus of claim 13 wherein the workpiece holder can be rotated.
18. The apparatus of claim 13 further comprising a steam flow line leading from the steam generator into the process chamber, and an ozone flow line leading from the ozone generator directly or indirectly into the steam flow line, for mixing the ozone with the steam before the ozone and the steam are supplied into the process chamber.
19. An apparatus for processing a workpiece, comprising:
a process chamber;
a workpiece holder in the process chamber for holding the workpiece;
means for delivering steam into the process chamber;
means for delivering ozone into the process chamber; and
means for cooling the workpiece to a temperature lower than a temperature of the steam.
20. The apparatus of claim 19 further comprising means for forming a layer of liquid on the first side of the workpiece, and for controlling the thickness of the layer of liquid.
21. The apparatus of claim 19 further comprising chamber heating means for heating the chamber.
22. The apparatus of claim 19 with the workpiece holder having multiple workpiece holding positions.