Abstract:
A method and apparatus for removing particle, metallic and organic contamination from the wafers used in fabricating integrated circuits is disclosed. In the preferred embodiment, the method comprises the step of placing the wafers to be processed in a vessel or container constructed of a very pure metal, and upon which a surface oxide will quickly form in air. The metal vessel or container is then filled with a cleaning solvent such as sulfuric acid, and are ultrasonically vibrated to remove the contamination. The ultrasonic vibration causes an acoustic streaming of the sulfuric acid, leading to a microflow of the solvent across the surface of the wafer at speeds on the order of several meters per second. This microflow provides for an quick and efficient cleaning of the wafer at reduced temperatures, thereby increasing the overall throughput of the planar fabrication process. The apparatus comprises a vessel or container constructed from a very pure metal, and containing an acidic cleaning solvent. The metal vessel or container is coupled to an ultrasonic vibrating device which ultrasonically vibrates the vessel or container, thereby cleaning the wafers.
Abstract:
A wafer dryer and method featuring a nebulizer which emits a pressurized drying liquid stream that converges with an opposed pressurized non-reactive carrier gas stream to produce a drying liquid fog. The pressurized non-reactive gas spray device is disposed partially within a tub and partially within a wafer bath vessel housing a wafer to be dried. The tub has a vent port for allowing the drying liquid fog to pass into the wafer bath vessel to adhere to exposed wafer surfaces and displace remaining liquid on wafer surfaces, thus drying the wafer. The tub may further include a drain for draining drying liquid not converted into the fog or which has condensed. The vent also may include means for retaining larger drying liquid fog particles which allows smaller drying liquid fog particles to pass into the wafer bath vessel.
Abstract:
Method and system for controllable deposit of copper onto an exposed surface of a workpiece, such as a semiconductor surface. A seed thickness of copper is optionally deposited onto the exposed surface, preferably using oxygen-free liquid ammonia to enhance this deposition. The workpiece exposed surface is then immersed in an electroplating solution, including copper and liquid ammonia at a suitable pressure and temperature, and copper is caused to plate onto the exposed surface at a controllable rate. When the copper deposited on the exposed surface reaches a selected total thickness, electroplating is discontinued, the electroplating solution is removed, and the gaseous and liquid ammonia are recovered and recycled for re-use.
Abstract:
Method and apparatus for drying and/or cleaning a workpiece, such as an electronic part, semiconductor wafer, printed circuit board or the like. As the workpiece is withdrawn from a processing liquid, a selected drying liquid, such as hydrofluoroether (HFE) or an HFE azeotrope, that has a very small surface tension, is volatile, and has a density that is greater than the processing liquid density, is sprayed on, dribbled on or otherwise transferred to an exposed surface of the workpiece. The workpiece can be dried in 7-45 seconds, or less, in most situations and can be cleaned using the invention. Drying and/or cleaning can be performed in a single workpiece process, a single workpiece continuous process or a batch process.
Abstract:
Methods for cleaning and/or drying objects that may have been wetted or contaminated in a manufacturing process. The objects are submerged in a rinse liquid in an enclosed chamber, and aerosol particles from a selected liquid are introduced into the chamber above the rinse liquid surface, forming a thin film on this surface. As the rinse liquid is slowly drained, some aerosol particles settle onto the exposed surfaces of the objects, and displace and remove rinse liquid residues from the exposed surfaces, possibly by a "chemical squeegeeing" effect. Surface contaminants are also removed by this process which may be performed at about room temperature. Chamber pressure is maintained at or near the external environment pressure as the rinse liquid is drained from the chamber. Inert gas flow is employed to provide aerosol particles of smaller size and/or with greater dispersion within the chamber. Continuous filtering and shunt filtering are employed to remove most contaminants from the selected liquid. A flow deflector redirects initial flow of the selected liquid to a supplementary filter, to remove most of the contaminant particle "spike" that appears when a system is first (re)activated. An improved surface for aerosol particle production is provided.
Abstract:
Method and apparatus for drying objects that may have been wetted in a manufacturing The objects are submerged in a rinse liquid in an enclosed chamber, and aerosol particles from a selected drying liquid are introduced into the chamber above the rinse liquid surface, forming a thin film on this surface. As the rinse liquid is slowly drained, some aerosol particles settle onto and form a film on the exposed surfaces of the objects, and displace and remove rinse liquid residues from the exposed surfaces. Surface contaminants are also removed by this process.
Abstract:
A composite cathode active material/current collector product useable as a component of a cathode for secondary batteries without the need for a separate current collector, which comprises a wire having a conductive interior portion of a transition metal and an exterior portion of an intercalatable layered transition metal chalcogenide, is made by a method which involves reacting a transition metal wire with a vapor of a chalcogen or a hydrogen chalcogenide.
Abstract:
A chalcogenide cathode is made by applying a slurry of a mixture containing at least one intercalatable layered transition metal chalcogenide cathode active material, a conductivity enhancing agent and a binding agent in a vehicle therefor to a high porosity current collector substrate which has been previously treated by applying and drying an adhesion promoting agent thereon and then heating the substrate in an inert atmosphere to drive off the vehicle and coalesce the binding agent.