1. Field of the Invention
The present invention relates to fixtures for the processing of workpieces in a supercritical fluid, and more particularly relates to fixture and methods for clamping workpieces in a workplace to enable the optimized exposure thereof to a stream or flow of a supercritical fluid.
2. Discussion of the Prior Art
In the technology of producing articles or workpieces, such as semiconductor devices which may have film layers applied thereto, is frequently necessary to process these in a workplace incorporating an environment constituted of supercritical fluids, wherein a surface or surfaces of the workpiece is or are exposed to a flow or stream of the supercritical fluid, and in which it is vital that the film and/or the workpiece is suitably protected from any possible damage or destruction.
Concerning the foregoing, the workpiece may be arranged in a suitable pressure vessel under a high-pressure condition, wherein the workpiece is then exposed to the stream or flow of the supercritical fluid. However, difficulties have been encountered in being able to arrange the workpieces in an optimized orientation relative to the fluid flow or stream of the supercritical fluid to which they are exposed in the pressure vessel.
Accordingly, in order to be able to take full advantage of the streams or flow directions of the supercritical fluids within the pressure vessel which impinge against the surface (or surfaces) of the workpiece, pursuant to the present invention there are provided novel and unique workplace fixtures employing in processing a workpiece in the supercritical fluid medium which affords the greatest degree of efficiency and efficacy in the treatment of the workpiece.
On the one hand, pursuant to a first embodiment of the invention, there may be provided a rotatably indexable chuck or locator mounting the workpiece and enabling orientating the latter in specific static pitch position within a high pressure vessel in order to subject the workpiece to a full frontal exposure to the supercritical fluid stream within the vessel. This mounting arrangement facilitates a film-protective treatment of the workpiece being processed in the flow path of the supercritical fluid stream while oriented in selectively indexed rotational positions.
Pursuant to another embodiment of the invention, a mounting fixture in the chamber of the pressure vessel may comprise a cup-shaped holder for receiving the workpiece, which facilitates the latter to be loaded thereon and immersed in the supercritical fluid or liquid. Suitable orifices in the chamber are provided to be enable excess liquid to drain off the workpiece down to a point whereby any forces are equalized, such as the surface tension, which will maintain the workpiece in an immersed condition while minimizing the amount of liquid which is to be processed through the pressure vessel.
Accordingly, it is a primary object of the present invention to provide a workplace incorporating a workpiece mounting fixture which will facilitate the processing of the workpiece in a supercritical fluid.
Another object of the present invention is to provide a novel workpiece mounting fixture which will facilitate the rotatably adjustable indexed positioning of the workpiece within the chamber of a high-pressure vessel while being subjected to a flow of a supercritical fluid enabling the processing or treatment thereof.
Yet another object of the present invention is to provide a workplace including a fixture in a high-pressure vessel in which a workpiece is adapted to be contained in a holder enabling excess amounts of a supercritical liquid to be drained to impart a balancing of surface tensions so as to maintain the workpiece in a immersed condition while minimizing the quantity of the liquid to be processed.
A still further object of the invention resides in the provision of methods of implementing the utilization of the above-mentioned fixtures processing workpieces in a supercritical fluid or liquid in a pressurized environment so as to facilitate the efficacious and efficient processing thereof.