Abstract:
A method for carrying out positive tone lithography with a carbon dioxide solvent system is carried out by (a) providing a substrate having a polymer resist layer formed thereon; (b) exposing at least one portion of the polymer resist layer to radiant energy to form at least one light field region in the polymer resist layer; and then (c) contacting the polymer resist layer to a carbon dioxide solvent system, the solvent system preferably comprising a polar group, under conditions in which the at least one light field region is preferentially removed.
Abstract:
A method of displacing a supercritical fluid from a pressure vessel (e.g., in a microelectronic manufacturing process), with the steps of: providing an enclosed pressure vessel containing a first supercritical fluid (said supercritical fluid preferably comprising carbon dioxide); adding a second fluid (typically also a supercritical fluid) to said vessel, with said second fluid being added at a pressure greater than the pressure of the first supercritical fluid, and with said second fluid having a density less than that of the first supercritical fluid; forming an interface between the first supercritical fluid and the second fluid; and displacing at least a portion of the first supercritical fluid from the vessel with the pressure of the second, preferably fluid while maintaining the interface therebetween.
Abstract:
A system for the controlled addition of detergent formulations and the like to a carbon dioxide cleaning apparatus comprises: (a) a high pressure wash vessel; (b) an auxiliary vessel; (c) a drain line connecting the auxiliary vessel to the wash vessel; (d) optionally but preferably, a separate vent line connecting the auxiliary vessel to the wash vessel; (e) a detergent reservoir; and (f) a detergent supply line connecting the detergent reservoir to the auxiliary vessel. An advantage of this apparatus is that, because the detergent formulation can be pumped into the auxiliary vessel in a predetermined aliquot or amount, which predetermined aliquot or amount can then be transferred into the wash vessel where it combines with the liquid carbon dioxide cleaning solution, the detergent formulation can be added to the cleaning solution in a more controlled or accurate manner. An alternate embodiment adapted for the addition of aqueous detergent formulations and the like to a carbon dioxide dry cleaning system under turbulent conditions comprises: (a) a high pressure wash vessel; (b) a filter; (c) a carbon dioxide cleaning solution drain line interconnecting the wash vessel to the filter; (d) a carbon dioxide cleaning solution supply line connecting the filter to the wash vessel; (e) a first high pressure pump (i.e., a pump that is capable of pumping liquid solutions comprising liquid carbon dioxide) operably connected to the drain line; (f) a detergent formulation reservoir; (g) a detergent formulation supply line connecting the reservoir to the carbon dioxide cleaning solution supply line; and (h) a second high pressure pump operably connected to the detergent formulation supply line for transferring detergent formulation from the detergent formulation reservoir into the carbon dioxide cleaning solution under turbulent conditions.
Abstract:
A method of cleaning and removing solid particles during a manufacturing process from a microelectronic device such as a resist-coated semiconductor substrate, a MEM's device, or an optoelectronic device comprising the steps of: (a) providing a partially fabricated integrated circuit, MEM's device, or optoelectronic device having water and entrained solutes on the substrate; (b) providing a densified (e.g., liquid or supercritical) carbon dioxide cleaning composition, the cleaning composition comprising carbon dioxide and a cleaning adjunct, the cleaning adjunct selected from the group consisting of cosolvents, surfactants, and combinations thereof; (c) immersing the surface portion in the densified carbon dioxide cleaning composition to remove solid particles from the surface portion; and then (d) removing the cleaning composition from the surface portion. Process parameters are controlled so that the cleaning composition is maintained as a homogeneous composition during the immersing step, the removing step, or both the immersing and removing step, without substantial deposition of the drying/cleaning adjunct or solid particles on the substrate.
Abstract:
A method for dry-cleaning articles such as fabrics and clothing in carbon dioxide. The article includes a stained portion or region, which is pretreated with a pretreatment composition prior to initiating the cleaning cycle. The pretreatment step is followed by contacting the pretreated article to be cleaned with a liquid dry cleaning composition for a time sufficient to clean the article. The liquid dry-cleaning composition comprises a mixture of carbon dioxide, a surfactant, and an organic co-solvent. After the contacting step, the article is separated from the liquid dry cleaning composition. The pretreatment composition, in a preferred embodiment, comprises at least one of (a) a surfactant; (b) d-limonene, and (c) a C12-C15 alkane co-solvent. Preferably the pretreatment composition comprises at least two, and in some particularly preferred embodiments, the pretreatment composition comprises all three, of the aforesaid ingredients.
Abstract:
A method for conserving carbon dioxide vapor in a carbon dioxide dry cleaning system employing a liquid carbon dioxide cleaning solution to clean articles, where the method includes removing carbon dioxide vapor from a wash tank to a vapor tank, storing the carbon dioxide vapor in the vapor tank; and charging the wash tank with carbon dioxide vapor from the vapor tank. The method may be performed as part of a wash cycle that includes filling the wash tank with cleaning solution, washing articles to be cleaned in the wash tank, and emptying the cleaning solution out of the wash tank. An apparatus may also be employed for conserving carbon dioxide vapor in a carbon dioxide dry cleaning system employing a liquid carbon dioxide cleaning solution to clean articles, where the apparatus includes a wash tank for contacting the articles to be cleaned with the liquid carbon dioxide cleaning solution, a working tank for storing liquid carbon dioxide cleaning solution, a vapor tank for storing carbon dioxide vapor, a first piping system providing fluid communication between the wash tank and the vapor tank, where the first piping system includes a first line and a first valve residing in the first line, and a second piping system providing fluid communication between the working tank and the wash tank. Methods and apparatus for collecting liquid carbon dioxide in a collecting tank are also provided.
Abstract:
A cleaning apparatus adapted for use with a carbon dioxide cleaning medium comprises a body member, a door connected to the body member and together with the body member forming a pressure vessel, a basket disposed within the body member, a motor contained within the pressure vessel, and a drive mechanism contained within the pressure vessel for rotating the basket with the motor. Because the motor and drive mechanism are both contained within the pressure vessel, the need for a rotating shaft that penetrates the pressure vessel, and which must be sealed at least in part against the high pressure liquid contained therein, is obviated.
Abstract:
A method of treating a substrate comprises contacting a surface of said substrate, with a pressurized fluid comprising carbon dioxide and a surface treatment component, the surface treatment component being entrained in the pressurized fluid and contacting the surface so that the surface treatment component lowers the surface tension of the surface of the substrate and treats the substrate. The contacting step is preferably carried out by immersion, the fluid is preferably a liquid or supercritical fluid, the substrate is preferably a metal or fabric substrate, and the surface treatment component is preferably a fluoroacrylate polymer.
Abstract:
A cleaning apparatus adapted for cleaning fabrics, garments and the like with a carbon dioxide cleaning medium comprises a wash vessel having a wall portion; a rotating basket positioned in the wash vessel; a drive shaft penetrating the wash vessel wall portion, the shaft operatively associated with the rotating basket; a double mechanical seal connected to the wall portion with the drive shaft passing therethrough; a seal liquid reservoir; a seal liquid inlet line connected to the seal liquid reservoir and the double mechanical seal and configured to supply seal liquid to the double mechanical seal; and a pump, compressed gas line, or other pressure supply means operatively associated with the seal liquid reservoir for maintaining the pressure of seal liquid in the double mechanical seal sufficient to seal the rotating shaft when the wash vessel contains a liquid carbon dioxide cleaning medium from escape of cleaning medium around the rotating shaft. Means such as a pump operatively associated with inlet and outlet lines are provided for circulating liquid carbon dioxide cleaning medium through the wash vessel during cleaning of articles therein. A motor or other drive means is operatively associated with the drive shaft for rotating the rotating basket during cleaning of articles therein. The seal liquid is preferably selected to be compatible with (e.g., soluble in) the cleaning medium.
Abstract:
A composition useful for the extraction of metals and metalloids comprises (a) carbon dioxide fluid (preferably liquid or supercritical carbon dioxide); and (b) a polymer in the carbon dioxide, the polymer having bound thereto a ligand that binds the metal or metalloid; with the ligand bound to the polymer at a plurality of locations along the chain length thereof (i.e., a plurality of ligands are bound at a plurality of locations along the chain length of the polymer). The polymer is preferably a copolymer, and the polymer is preferably a fluoropolymer such as a fluoroacrylate polymer. The extraction method comprises the steps of contacting a first composition containing a metal or metalloid to be extracted with a second composition, the second composition being as described above; and then extracting the metal or metalloid from the first composition into the second composition.