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Patent Application Titled "Process Liquid Supply Apparatus Operating Method, Process Liquid Supply Apparatus and Non-Transitory Storage Medium"...

February 27, 2014



Patent Application Titled "Process Liquid Supply Apparatus Operating Method, Process Liquid Supply Apparatus and Non-Transitory Storage Medium" Published Online

By a News Reporter-Staff News Editor at Politics & Government Week -- According to news reporting originating from Washington, D.C., by VerticalNews journalists, a patent application by the inventors MARUMOTO, Hiroshi (Koshi City, JP); TAKAYANAGI, Koji (Koshi City, JP); ADACHI, Kenji (Koshi City, JP), filed on August 1, 2013, was made available online on February 13, 2014.

The assignee for this patent application is Tokyo Electron Limited.

Reporters obtained the following quote from the background information supplied by the inventors: "A liquid process is performed in a manufacture process of a semiconductor device by supplying liquid chemicals (e.g., a resist liquid, an acid or alkali cleaning liquid, a solvent, a precursor-containing liquid for forming an insulation film, etc.) from a nozzle to a substrate. Such a liquid chemical supply apparatus is configured to remove foreign substances by a filter unit disposed in a supply passage.

"Bubbles may be created in the aforementioned process due to gas dissolved in a resist or a liquid chemical. A line width of a pattern becomes finer and finer. Thus, cautious measures should be taken for fine bubbles that are not problematic in the past.

"A coating apparatus for coating the aforesaid liquid chemical performs a gas removal process of removing the gas in a filter unit in order to remove foreign substances contained in a process liquid. The gas removal process makes the process liquid permeate through the filter unit (hereinafter, referred to as 'a filter wetting process') when the filter unit is newly mounted or replaced. For example, as a method of performing the filter wetting process, filtering is performed under a positive pressure (pressure higher than an atmospheric pressure) using a pressure of a N.sub.2 gas or a pressure produced by a pump after setting the filter unit, and thereafter the number of defects on a substrate caused by the bubbles is monitored. Further, in the method of performing the filter wetting process, the gas in the filter unit is regarded as fully removed when the number of defects decreases to a predetermined level, and the filter wetting process is finished accordingly.

"However, in this method, to reduce the cost for mass production, the process liquid amount consumed before the filter unit starts to operate should be reduced. Additionally, the operative time should be shortened.

"By way of another example, the filter unit communicating with a process liquid ejecting nozzle may have a structural feature for reducing the number of bubbles in the process liquid passing through the filter unit. In this example, the filter unit may have repetitive prominences and depressions on a wall surface, but this may lead to complexity in manufacturing the filter unit."

In addition to obtaining background information on this patent application, VerticalNews editors also obtained the inventors' summary information for this patent application: "Various embodiments of the present disclosure provide a technique for accomplishing the reduction in the liquid chemical spent for removing bubbles from a filter unit as well as the shortening in an operative time when the filter unit is newly mounted in a liquid chemical supply passage or the filter unit provided in the liquid chemical supply passage is replaced.

"According to a first aspect of the present disclosure, there is provided a method of operating a process liquid supply apparatus. The process liquid supply apparatus includes a filter unit, a discharge outlet for a gas in a process liquid, and a liquid sending unit, which are provided in a flow passage located between a process liquid supply source and a nozzle in that order from an upstream side. The process liquid supply apparatus supplies the process liquid to target objects through the nozzle by the liquid sending unit. The method includes filling the filter unit with the process liquid from an upstream side of the filter unit to a downstream side of the filter unit after newly mounting or replacing the filter unit, and repeating a depressurization filtering process and a pressurization filtering process for a predetermined number of times. The depressurization filtering process depressurizes the process liquid in the downstream side of the filter unit and thereby allows the process liquid to permeate through the filter unit. The pressurization filtering process pressurizes the process liquid from the upstream side of the filter unit and thereby allowing the process liquid to permeate through the filter unit.

"According to a second aspect of the present disclosure, there is provided a process liquid supply apparatus which includes a filter unit, a discharge outlet for a gas in a process liquid, and a liquid sending unit, which are provided in a flow passage located between a process liquid supply source and a nozzle in that order from an upstream side, and supplies the process liquid to target objects through the nozzle by the liquid sending unit. The process liquid supply apparatus includes a control unit configured to output a control signal for performing filling the filter unit with the process liquid from an upstream side of the filter unit to a downstream side of the filter unit after newly mounting or replacing the filter unit; and repeating a depressurization filtering process and a pressurization filtering process for a predetermined number of times. The depressurization filtering process depressurizes the process liquid in the downstream side of the filter unit and thereby allows the process liquid to permeate through the filter unit. The pressurization filtering process pressurizes the process liquid from the upstream side of the filter unit and thereby allowing the process liquid to permeate through the filter unit.

"According to a third aspect of the present disclosure, there is provided a non-transitory storage medium storing a computer program for use in an apparatus, which performs the method of operating the process liquid supply apparatus using the process liquid supplied from the process liquid supply source. The computer program is configured to execute the method of operating the process liquid supply apparatus according to the first aspect of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

"The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure.

"FIG. 1 is configuration diagram showing one embodiment of a resist supply apparatus constituting a resist coating apparatus according to one embodiment of the present disclosure.

"FIG. 2A is a longitudinal sectional view showing one example of a filter unit.

"FIG. 2B is a perspective view showing one example of a filtering portion.

"FIG. 3 illustrates an example of a structure of a pump unit.

"FIG. 4 is a fragmentary configuration diagram showing a resist flow in the vicinity of the filter unit during pressurization filtering.

"FIG. 5 is a configuration diagram showing a resist flow in the vicinity of the filter unit in during depressurization filtering.

"FIG. 6 is a configuration diagram showing a resist flow in the vicinity of the filter unit during pressurization filtering.

"FIGS. 7A to 7D schematically show an extraction mechanism of bubble nucleuses in a supersaturated state.

"FIG. 8A to 8C schematically show a collapse mechanism of bubble nucleuses.

"FIG. 9 is a graph showing a relationship between a potential of a bubble nucleus and a radius of a bubble nucleus.

"FIG. 10 is a graph showing a relationship between liquid permeability and time in a capillary phenomenon.

"FIG. 11 is a graph showing results of comparative experiments for verifying the effects of the embodiments according to the present disclosure.

"FIG. 12 is a graph showing results of comparative experiments for verifying the effects of the embodiments according to the present disclosure."

For more information, see this patent application: MARUMOTO, Hiroshi; TAKAYANAGI, Koji; ADACHI, Kenji. Process Liquid Supply Apparatus Operating Method, Process Liquid Supply Apparatus and Non-Transitory Storage Medium. Filed August 1, 2013 and posted February 13, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=6507&p=131&f=G&l=50&d=PG01&S1=20140206.PD.&OS=PD/20140206&RS=PD/20140206

Keywords for this news article include: Tokyo Electron Limited.

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Source: Politics & Government Week


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