Claims
- 1. A system for processing a workpiece comprising:
an interface section; a process section; a process robot moveable to carry a workpiece from the interface section to the process section; a processor unit in the process section, with the processor unit having a process chamber, a drain opening in the process chamber, and a process chamber driver for pivoting the process chamber to drain liquid out of the process chamber by moving the drain opening down to the level of the liquid in the process chamber.
- 2. The system of claim 1 where the process chamber has a curved sidewall and the drain opening is in the curved sidewall.
- 3. The system of claim 2 wherein the drain opening comprises a slot in the curved sidewall connecting to a drain port.
- 4. The system of claim 2 where the process chamber is generally cylindrical and has a central axis, and the process chamber driver pivots the process chamber about an axis parallel to the central axis of the generally cylindrical process chamber.
- 5. The system of claim 1 wherein the process chamber pivots about a horizontal axis.
- 6. The system of claim 1 further comprising at least one manifold in the process chamber for introducing a fluid into the process chamber.
- 7. The system of claim 1 where the process chamber driver pivots the process chamber from a first position where the drain opening is adjacent to the top of the process chamber, to a second position, where the drain outlet is adjacent to the bottom of the process chamber.
- 8. The system of claim 1 further comprising a rotor rotatably supported within the process chamber, with the rotor having positions for holding workpieces.
- 9. The system of claim 1 further comprising a door assembly including a closure frame attachable to the process chamber.
- 10. A system for processing a workpiece comprising:
an interface section; a process section; a process robot moveable to carry a workpiece from the interface section to the process section; a processor unit in the process section, with the processor unit having a process chamber including:
a drain opening in the process chamber; a process chamber driver for pivoting the process chamber to drain liquid out of the process chamber; and a rotor rotatably supported within the process chamber.
- 11. The system of claim 10 further comprising at least one manifold in the process chamber, and a flexible supply line joined to the manifold, with the flexible supply line moving with the process chamber as the process chamber pivots.
- 12. The system of claim 10 further comprising a switchable drain in the process chamber at a position spaced apart from the drain opening.
- 13. The system of claim 10 where the process chamber comprises a backwall joined to a cylindrical sidewall, and with the process chamber having an open front end, and further comprising door means for closing off the open front end of the process chamber.
- 14. The system of claim 1 further comprising a first manifold in the process chamber connected to a source of an organic solvent vapor, and a second manifold in the process chamber connected to a source of water.
- 15. The system of claim 1 where the process chamber is supported only by the process chamber driver.
- 16. The system of claim 10 further comprising a spin motor connected to the rotor.
- 17. A method for processing a workpiece comprising the steps of:
supporting the workpiece on a support within a process chamber; closing the process chamber; filling the process chamber with a rinse liquid to at least partially immerse the workpiece in the liquid; and removing the liquid from the chamber by moving the chamber so that a drain opening in the chamber moves into a position where the liquid moves through the drain opening via gravity and out of the process chamber.
- 18. The method of claim 17 where the drain opening is in a sidewall of the chamber and the liquid is removed by pivoting the chamber to bring the drain opening to the level of liquid in the chamber.
- 19. The method of claim 17 further including the step of spinning the support and the workpiece in the process chamber after removing the liquid.
- 20. The method of claim 17 further including the step of spraying a process fluid onto the workpiece in the chamber, before filling the process chamber with the rinse liquid.
- 21. The method of claim 20 wherein the rinse liquid comprises water.
- 22. A method for processing a workpiece comprising the steps of:
supporting the workpiece in a rotor within a process chamber; closing the process chamber; filling the process chamber with a rinse liquid to at least partially immerse the workpiece in the liquid; removing the liquid from the chamber by moving the chamber so that a drain opening in the chamber moves into a position where the liquid moves through the drain opening via gravity and out of the process chamber; and spinning the rotor and the workpiece.
- 23. The method of claim 22 further comprising the step of spraying the workpiece with a gas.
- 24. A method for cleaning a workpiece, comprising the steps of:
supporting the workpiece within a process chamber; filling the process chamber with a rinse liquid to a level sufficient to immerse the workpiece in the liquid; removing the liquid from the chamber by moving the chamber so that a drain opening in the chamber moves into a position where the liquid moves through the drain opening via gravity and out of the process chamber; and introducing a vapor of an organic solvent into the chamber.
- 25. The method of claim 24 further comprising the step of spinning the workpiece.
- 26. The method of claim 24 further comprising the step of introducing a gas into the chamber.
- 27. The method of claim 24 further comprising the step of introducing sonic energy into the process chamber when the workpiece is immersed.
- 28. A processor unit for processing a workpiece, comprising:
a process chamber; a workpiece support in the process chamber; a drain opening in the process chamber; and a process chamber driver for pivoting the process chamber to move the drain opening from a first position to a second position relative liquid in the process chamber, to drain liquid out of the process chamber.
- 29. The processor of claim 28 where the workpiece support comprises a rotor rotatably positioned within the process chamber.
FIELD OF INVENTION
[0001] This Application incorporates by reference U.S. patent application Ser. Nos. ______(260/291) and______(265/266), both filed on Jul. 16, 2001.
[0002] The invention relates to surface preparation, processing and cleaning of workpieces, such as semiconductor wafers, flat panel displays, rigid disk or optical media, thin film heads, or other workpieces formed from a substrate on which microelectronic circuits, data storage elements or layers, or micro-mechanical elements may be formed. These and similar articles are collectively referred to here as a “workpiece”.
[0003] Surface preparation, such as cleaning, etching, and stripping, is an essential and important element of the manufacturing process for semiconductor wafers and similar workpieces. Surface preparation steps are commonly performed, using liquid corrosive, caustic, or solvent chemicals, or using vapor phase chemicals. Surface preparation of workpieces is performed to prepare or condition the surface for a subsequent process step.
[0004] Cleaning is a critical step in manufacturing semiconductors and similar products. Cleaning involves the use of chemical formulations to remove contaminants, such as oxides, particles, metals, or organic material, while maintaining the cleanliness and integrity of the surface of the workpiece. Some liquid, gas or vapor phase chemicals when applied to a workpiece, result in surface characteristics that are more susceptible to contamination than others. For example, application of hydrofluoric acid (HF) to the surface of a workpiece will remove oxide from the silicon surface, resulting in a surface that is active. Workpieces in general, and especially workpieces having an active surface, are constantly susceptible to contamination by airborne microscopic particles. Contamination can also occur in the cleaning process, when the liquid process media is removed from the surface of the workpiece.
[0005] Thus, to minimize contamination of the workpiece, it is advantageous to perform a sequence of surface preparation steps within a controlled environment, that preferably occupies a relatively small amount of fabrication facility space, and in which exposure to contamination sources is minimized. Accordingly, it is an object of the invention to provide improved surface processing methods and apparatus.
[0006] Cleaning workpieces while avoiding or minimizing contamination has long been an engineering challenge. Workpieces are often cleaned with a spray or bath of de-ionized water. The water is then removed, often in the presence of an organic solvent vapor, such as isopropyl alcohol, which lowers the surface tension of the water. This helps to prevent droplets of water from remaining on and contaminating the workpiece.
[0007] Various cleaning methods and systems and various rinsing and drying methods and apparatus have been proposed and used. In a typical system, wafers are immersed in a vessel. A mechanism is provided to hold the wafers. Another mechanism is provided to lift the wafers out of the liquid, by pushing them up from below. While this technique has been used, it can result in trapping of liquid in or around the spaces where the wafers contact the holding mechanism, resulting in increased contamination. It is also complicated by the need for the lifting mechanism. In an alternative system, the wafers are held in a fixed position while the liquid is drained away from below. This technique has less tendency for trapping liquid. However, as the liquid level drops, the solvent vapor above the liquid is absorbed by the liquid. Consequently, the top sections of the wafer are exposed to liquid which is different from the liquid at the bottom sections of the wafers. This potentially results in non-uniform processing. Accordingly, while these and other techniques have been used with varying degrees of success, there is still a great need for improved systems and methods for cleaning workpieces.
[0008] It is therefore also an object of the invention to provide an improved system and method for cleaning workpieces.