DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Objections
Claims 1, 6, 10, and 20 are objected to because of the following informalities: Claim 1 recites “shrunk due to after performing” in which “due to” and “after” convey the same meaning and is therefore redundant, so one of them should be omitted. Claim 6 recites “adjusting etching a plurality of conditions” but should instead recite --adjusting a plurality of etching conditions-- as seen in claim 17. Claim 10 recites “and” but should instead recite --or--. Claim 20 recites “condition” but should instead recite --conditions--. Appropriate correction is required.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (U.S. 2022/0308464) in view of Cullins (U.S. 2021/0302827).
Liu et al. teaches a method of manufacturing a semiconductor device includes cleaning a particle (defect) from a surface of a reticle (mask) in a treatment device by exposing the surface of the reticle to a directional stream of plasma wind (gas etching particles). The directional stream of plasma wind is generated by an ambient plasma generator at an oblique angle with respect to a perpendicular plane to a surface of the reticle for a predetermined plasma exposure time. After the cleaning, the method also includes transferring the reticle from the treatment device to an exposure device for lithography operation. The method further includes projecting a layout pattern of the reticle using an incident extreme UV (EUV) radiation of an EUV source of the exposure device onto a photo resist layer of a wafer. In an embodiment, the method further includes directing a gas flow of helium into the ambient plasma generator to generate the directional stream of plasma wind. In an embodiment, the cleaning the surface of the reticle include cleaning a first region of two or more non-overlapping regions on the surface of the reticle in the treatment device by exposing the first region of the two or more non-overlapping regions on the surface of the reticle to the directional stream of plasma wind at the oblique angle for the predetermined plasma exposure time such that each non-overlapping region comprises one or more particles; and repeat the cleaning on other regions of the two or more non-overlapping regions on the surface of the reticle to clean entire surface of reticle. In an embodiment, the method further includes applying a high intensity electric field to the gas flow of helium inside the ambient plasma generator to generate the directional stream of plasma wind. In an embodiment, the method further includes adjusting a width of an output opening of the ambient plasma generator to adjust a speed and angle of the directional stream of plasma wind. In an embodiment, the method further includes adjusting the oblique angle of the directional stream of plasma wind between 30 degrees and 80 degrees with respect to the perpendicular plane to the surface of the reticle to drive the particle off the surface of the reticle. In an embodiment, the method further includes adjusting a width of an output opening of an output port of the ambient plasma generator between 100 microns and 5 mm to adjust the angle and speed of the directional stream of plasma wind [0057] (claims 1-4, 6, 7, 10-14, 16, 17, and 20). Liu et al. also teaches impacting a particle on a wafer or on a reticle by the plasma wind disintegrates the particles. The oblique angle of the plasma wind causes the disintegrated parts of the particle to get a velocity parallel to the surface of the reticle or wafer because of the impact. In some embodiments, the parallel velocity of the disintegrated parts causes the disintegrated parts to be thrown out of the surface of the reticle or the wafer. In plasma wind, the gas atoms are excited at higher energy states or are ionized. In some embodiments, when the excited gas atoms return to the normal energy state, ultraviolet (UV) light may be released. The mixture of the plasma ion impact and the UV light interacts, e.g., physically interacts, with the particles and removes the particles [0018] (claims 6 and 17). Liu et al. also teaches FIGS. 2A and 2B show a handling system for transferring reticles and wafers between multiple locations. FIG. 2A shows a handling system 200, a reticle handling system, for transferring reticles between different locations. The handling system 200 transfers reticles between a reticle library 202, a treatment device 212, and an exposure device 214. The handling system 200 includes a robot device 206 with a robot arm, e.g., a wafer exchange device. The robot arm includes a first movable segment 204 and a second movable segment 208. The second movable segment 208 rotates around the first pivot point 205. The first movable segment 204 rotates around a second pivot point (not shown) inside the robot device 206 and further moves the first pivot point 205 and the second movable segment 208. The robot device 206 may rotate the first movable segment 204 and the second movable segment 208 around the respective pivot points to extend the robot arm to the reticle library 202, to the treatment device 212, or to the exposure device 214. In some embodiments, the robot device 206, the reticle library 202, the treatment device 212, and the exposure device 214 are maintained in vacuum condition (chamber). The exposure device 214 is described with respect to FIG. 4. The handling system 200 also includes a cleaning controller 260 coupled to the reticle library 202, the robot device 206, the treatment device 212, and the exposure device 214. In some embodiments, the cleaning controller 260 commands the robot device 206 to retrieve a reticle from the reticle library 202 and load the reticle to the treatment device 212 or to the exposure device 214. In some embodiments, the cleaning controller 260 commands the robot device 206 to retrieve the reticle from the treatment device 212 and to load the reticle to the exposure device 214. In some embodiments, the cleaning controller 260 commands the reticle library 202 to release one of the reticles to be retrieved. In some embodiments, the cleaning controller 260 commands the robot device 206 to load the reticle on a stage, e.g., a mask mounting stage (wafer chuck), of the treatment device 212 or a mask mounting stage of the exposure device 214 [0022-0023]. Liu et al. further teaches in some embodiments, as shown in FIG. 5C, the treatment device 550 includes a particle collector 565, e.g., a particle counter, attached by a pipe 524 to a nozzle 521. In some embodiments, the particle collector 565 exerts a vacuum to pull in the particles (purging) [0037] (claim 11).
Liu et al. also teaches in some embodiments, mask is a reflective mask and the layout pattern on the mask is projected by an extreme ultraviolet (EUV) radiation from an EUV light source onto the photo resist layer 15 to generate a resist pattern in the photo resist layer 15 on the semiconductor substrate 10 [0021].
Liu et al. does not specify the layers of the reticle (mask) nor the etching rates of said layers.
However, Cullins teaches a known photomask, specifically an EUV photomask, comprising a Bragg reflector 42 on a substrate 40. The substrate 40 may be a low thermal expansion material such as fused silica. The Bragg reflector 42 includes alternating layers of amorphous silicon (α-Si) 44-1 through 44-n and molybdenum (Mo) 46-1 through 46-n, such as 40 or more pairs of layers of amorphous silicon (α-Si) and molybdenum (Mo). The photomask 22 further includes a capping layer 48 (e.g., ruthenium) on the Bragg reflector 42, a patterned absorber layer 50 (e.g., tantalum nitride, tantalum boron nitride, etc.) on the capping layer 48, and a patterned anti-reflection coating (ARC) 52 (e.g., an oxide) on the patterned absorber layer 5 [0026] (claims 1 and 11). Cullins also teaches the photomask 22 undergoes an etch process to remove particulates and pieces created from the pellicle 32. The etch process can be any etch process that has a high selectivity between a material of the pellicle 32 (e.g., the particulates) and each material of the photomask 22. In some examples, the etch process is a wet etch process, although in other examples, a dry etch process can be implemented. Regardless of the etch process implemented, the etchant that is used has a low etch rate of each material of the photomask 22 (e.g., absorber layer, capping layer, etc.) and a higher etch rate of a material of the pellicle 32 to remove particulates or pieces of the pellicle 32 from the photomask 22 without damaging the photomask 22 [0034] (claims 8, 9, 15, and 19). It should be noted that the selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 65 USPQ 297 (1945). See MPEP 2144.07. In the instant case, both Liu et al. and Cullins are directed to masks and the process of cleaning them of defects while Cullins specifically teaches known layers of a typical mask used in EUV lithography.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the specific teachings of Liu et al. to include known reticle (photomask) layers as taught by Cullins and arrive at the instant claims through routine experimentation of selecting well known materials suitable in EUV lithography with a reasonable expectation of success.
With regard to claims 5 and 18, Liu et al. teaches when the reticle (mask) is used during a lithographic process, particles and hydrocarbon contamination (defects) may build up on the reticles [0016].
Liu et al. does not teach the particles (defects) comprise Sn, Al, Mo, Ni, Ta or combination thereof.
However, the reticle (mask) of Liu et al. modified by Cullins would necessarily result in particles (defects) having Mo or Ta as a result of the lithographic process of making the mask having a Mo/Si layer, a Ruthenium layer, and a Tantalum Nitride layer.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. U.S. 2010/0288302 and U.S. 2003/0000921.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANNA E MALLOY whose telephone number is (571)270-5849. The examiner can normally be reached 6:30-3:00 EST M-F.
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/Anna Malloy/Examiner, Art Unit 1737
/KEITH WALKER/Supervisory Patent Examiner, Art Unit 1735
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