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
Claim 19 is objected to because it recites “focusing the lens to cause paraxial rays of the plurality of secondary charged-particle beams on a plane of the detector” which appears to omit the phrase “to focus” after “beams.”
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1, 2, 7, 9, 14-15, and 20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by US 2019/0355544 A1 [hereinafter Riedesel].
Regarding Claim 1:
Riedesel teaches a system (Abstract: multibeam charged particle system), comprising:
a multi-beam inspection apparatus configured to scan a sample and comprising a lens (Figs. 1 and 4, paras. [0054-0055, 0057, 0088, 0090]: primary electrons incident on sample 7 generate a plurality of secondary electron beamlets 9, the microscopy system includes projection lens 205, one or more dynamically controlled electrostatic lenses 260 and final lens 263(Fig 4));
a detector (Fig. 1- detector arrangement 209) configured to receive a plurality of secondary charged-particle beams in response to scanning the sample (Fig. 1 and paras. [0054, 0055]: projection lens 205 focuses the secondary beamlets 9 to an electron detector 207 of the detector arrangement 209); and
a controller (Fig. 1- controller 10) including circuitry communicatively coupled to the multi-beam inspection apparatus and the detector (Fig. 1 and para. [0062]: controller 10 controls the individual charged particle optical components and evaluates signals recorded by detector 209), the controller configured to:
focus the lens (Fig. 1- fast lens system 260) to adjust sizes of secondary beam spots, wherein the secondary beam spots are formed by the plurality of secondary charged-particle beams on the detector (Figs. 1 and 5C and paras. [0080,0083, 0093]: Secondary electron beamlets 9 are focused onto the surface of scintillator plate/detector 209, and form electron beam spots on that detector surface. Dynamic controller 170 determine appropriate voltage applying to the fast lens system 260 using algorithm 805 so that “the positions of the secondary electron beamlets 550 coincide with the centers of the sensitive areas 551 and the diameters of the light spots on the spatially resolved detection system 290 are minimized”);
cause, for each secondary charged-particle beam of the plurality of secondary charged-particle beams, outlier charged particles of the each secondary charged-particle beam to not be detected by the detector (Figs. 1-2,6 and paras. [0061, 0063-0064, 0072]: filter 208 filters secondary electrons according to their trajectories or beam paths before they are projected to the detector 209. As shown in Fig. 2, diaphragm 261 (Fig. 6) is placed at the crossover formed by lenses 210 and 211, the central opening 218 transmits electrons while the “outer portion…is non-transmissive”, preventing crosstalk between different beam paths); and
refocus the lens to adjust currents of a portion of the plurality of secondary charged-particle beams detected by the detector, wherein the outlier charged particles do not contribute to the currents (Claims 16-18. paras. [0027, 0029, 0093, 0096]: subsequently and repeatedly adjusting electrostatic lens 260 to refocus the secondary beamlets on the detector to compensate detector collection efficiency. Correcting the defocus changes the spatial distribution of the remaining secondary electrons on the finite detection region, thereby changing the detected signal intensity and consequently, the detected beam current. Because the outer-trajectory electrons are blocked by diaphragm 216 before reaching detector 209, the refocusing adjusts the detected currents of only the remaining transmitted portions of the secondary beamlets, without contribution from the blocked outlier electrons).
Regarding Claims 14 and 20:
Claims 14 and 20 each directing to a non-transitory computer-readable medium and a method of optimizing secondary charged particle collection efficiency, and recites substantially same subject matter of claim 1, and thus Riedesel also teaches claims 14 and 20.
Regarding Claims 2 and 15:
Riedesel teaches the system of claim 1 and computer-readable medium of claim 14, respectively. Riedesel further teaches wherein the controller is configured to focus the lens to adjust the sizes of the secondary beam spots to enable minimizing the sizes of the secondary beam spots (para. [0093]: controller 170 determines and applies voltage to lens 260 so that the secondary beamlets are correctly focused and their detector-plane spot diameters are minimized).
Regarding Claim 7:
Riedesel teaches the system of claim 1. Riedesel further teaches wherein the controller is configured to cause the outlier charged particles of the each secondary charged-particle beam to not be detected by the detector by adjusting a beam limiting aperture configuration to cause a beam limiting aperture of the beam limiting aperture configuration to be positioned upstream to the detector and to filter the outlier charged particles (Figs. 2 and 6, and paras. [0035, 0064]: place diaphragm 216 upstream detector 209 and physically filters outer-trajectory electrons via its center opening 216. “The alignment of focusing elements and sample high voltage bias is adjusted for optimal spot shape …For a crosstalk optimization a virtual aperture size can be changed via a projective cross over zoom system”).
Regarding Claim 9:
Riedesel teaches the system of claim 7. Riedesel further teaches wherein the controller is configured to refocus the lens to adjust the currents to enable, based on an aperture size of the beam limiting aperture, refocusing of the lens to adjust the currents (para. [0035] teaches two coordinated, real-time feedback adjustment includes adjusting focusing elements through feedback for optimal detector plane spot shape and adjust aperture size to optimize throughput vs. crosstalk, and such a dynamic alignment is repeatedly performed ([0027]). Since the selected aperture size determines the portion of each secondary beamlet transmitted toward detector, changing the aperture size changes the transmitted electron current, the next focus adjustment is therefore applied to the beam portion established by the aperture size).
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.
Claims 3, 8, 10, 13, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Riedesel.
Regarding Claims 3 and 16:
Riedesel teaches the system of claim 1 and computer-readable medium of claim 14, respectively. Although Riedesel does not expressly teaches wherein the controller is configured to refocus the lens to adjust the currents to enable maximizing the currents of the portion of the plurality of secondary charged-particle beams detected by the detector, Riedesel teaches focus adjustment changes detector collection efficiency and the controller uses feedback loops for direct optimization, for example, aperture size is controlled to optimize throughput versus crosstalk (paras. [0029, 0034-0035]). Riedesel also specifies that detector signal represents the intensity of the individual secondary beamlet (para. [0081]). Therefore, because Riedesel teaches adjusting secondary beam focus to compensate detector collection efficiency, it would have been obvious for an ordinary skilled person to continue the disclosed feedback adjustment until the detected currents reach their maximum values, subject to the disclosed crosstalk constraint, as detected current is the result-effective measure of detector collection efficiency.
Regarding Claim 8:
Riedesel teaches the system of claim 1. Riedesel also teaches wherein the controller is configured to cause the outlier charged particles of the each secondary charged-particle beam to not be detected by the detector by adjusting the beam limiting aperture configuration to cause the beam limiting aperture of the beam limiting aperture configuration and filter the outlier charged particles, as discussed in claim 7. Riedesel further teaches the Fig. 2 projection system can be provided with additional dynamically controlled electrostatic lenses, such as the dynamic lens system 260 described in Fig.2 and Riedesel does not restrict the added dynamic lens to a particular side of diaphragm 216.
Although Riedesel does not expressly teach the beam limiting aperture is to be positioned upstream to the lens, it would have been obvious for an ordinary skilled person to position the dynamic lens system 260 downstream of diaphragm 216 and upstream of detector 209. Such placement would permit diaphragm 216 first to establish the transmitted secondary beam portion and reduce crosstalk, while lens system 260 thereafter adjusts the detector plane focus and correction efficiency of those transmitted portions without changing which particles pass through diaphragm 216.
Regarding Claim 10:
Riedesel teaches the system of claim 7. Riedesel further teaches the controller is configured to refocus the lens to adjust the currents to enable refocusing of the lens to adjust the currents.
Changing the position of an aperture along the axis changes the portion of electrons transmitted to the detector, it also changes the resulting detected electron currents. Therefore, although Riedesel does not expressly teach the adjustment of current during refocusing is based on the position of the beam limiting aperture along a projection axis of the lens, it would have been obvious for an ordinary skilled person, in addition or as an alternative to adjusting aperture size, to adjust the aperture position to control crosstalk. As such during the subsequent feedback-controlled refocusing step lens 260 would adjust the currents of the transmitted beam portions established by the previously selected aperture position.
Regarding Claim 13:
Riedesel teaches the system of claim 7. Riedesel further teaches adjusting the projection system to optimize collection efficiency while reducing crosstalk via real-time feedback control and optimization (para. [0029]).
As such, it would have been obvious for an ordinary skilled person to adjust the focusing power of the lens incrementally, thereby moving the focal point toward or away from the detection plane, and to evaluate collection efficiency and crosstalk after each adjustment. Specifically,
when an adjustment increases collection efficiency while crosstalk remains below an acceptable predetermine limit, continuing in the same focus-search direction would move the system toward the optimum;
when collection efficiency decrease, reversing the focus-search direction would correct movement away from, or past, the optimum;
once collection efficiency reaches its maximum, further adjustment would provide no material benefit; and once crosstalk reaches the predetermined acceptable limit, further adjustment would defeat Riedesel’s stated objective of limiting crosstalk. Accordingly, it would have been obvious to stop refocusing upon either condition.
Claims 4 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Riedesel in view of US 2025/0104966 A1 [hereinafter Shubert].
Regarding Claims 4 and 17:
Riedesel teaches the system of claim 1 and computer-readable medium of claim 16, respectively. However, Riedesel does not expressly teach wherein the detector is a pixelated detector, and the controller is configured to cause the outlier charged particles of the each secondary charged-particle beam to not be detected by adjusting a number of pixels of a detector cell of the detector, wherein the pixels of the detector cell are configured to detect the plurality of secondary charged-particle beams.
Shubert teaches wherein the detector is a pixelated detector, and the controller is configured to cause the outlier charged particles of the each secondary charged-particle beam to not be detected by adjusting a number of pixels of a detector cell of the detector, wherein the pixels of the detector cell are configured to detect the plurality of secondary charged-particle beams (Fig. 8 and paras. [0080, 0082, 0104]: a detector set 625 contains 7 individual detection elements 623.1-623.7. The signals from the assigned elements are integrated by data-acquired unit 810 to produce the intensity signal for the corresponding beamlet. The controller modifies the assignment of detection elements to detector sets, and the modified set may have a different position, shape, or “number of detection elements”).
Therefore, it would have been obvious for an ordinary skilled person in the art, before the effective time of filing, to implement the detector of Riedesel as a pixelated detector and exclude outlier particles beams by adjusting the number of pixels of a detector cell of the detector to exclude peripheral pixels receiving outlier pixels, as a known alternative method to exclude outlier electrons and minimize crosstalk.
Claims 11-12 are rejected under 35 U.S.C. 103 as being unpatentable over Riedesel in view of US 2019/0378682 A1 [hereinafter Wang]
Regarding Claim 11:
Riedesel teaches the system of claim 1. However, Riedesel does not expressly teach wherein the detector is a pixelated detector, and the controller is configured to cause the outlier charged particles of the each secondary charged-particle beam to not be detected by the detector by selecting a subset of pixels from pixels covered by the each secondary charged-particle beam.
Wang teaches wherein the detector is a pixelated detector, and the controller is configured to cause the outlier charged particles of the each secondary charged-particle beam to not be detected by the detector by selecting a subset of pixels from pixels covered by the each secondary charged-particle beam (detector 300 includes individual sensing elements 311, 312, 313, etc. (Fig. 3A, para. [0124]). A controller may determine a first group within boundary 350 includes sensing elements at least partially covered by the same beam spot, and a second group within boundary 360 that is a subset of the first group and corresponds to the higher-intensity portion of the spot (Fig. 3F, paras. [0126-0127]. Wang further teaches detector element grouping and tailoring resulting data to optimize the tradeoff between crosstalk and second particles collection efficiency (para. [0413]).
Therefore, it would have been obvious for an ordinary skilled person in the art, before the effective time of filing, to implement the detector of Riedesel as a pixelated detector and selecting a subset of those pixels for electron detection, such that forming the output signals from the inner pixels group while excluding the lower-intensity peripheral pixels of the outer group, as a known alternative to prevent charged particles incident on the excluded peripheral pixels from contributing to the reported beamlet current.
Regarding Claim 12:
Riedesel teaches the system of claim 1. However, Riedesel does not expressly teach wherein the detector is a pixelated detector, and the controller is configured to refocus the lens to adjust the currents to enable, based on a detector cell size of the pixelated detector, refocusing of the lens to adjust the currents.
As discussed in claim 11, Wang teaches the subset of selected pixels define the effective detector cell and its effective collecting area. Increasing the number of selected pixels increases the size of the detector cell and allows a greater portion of the secondary electron to contribute to the detected current. Thus, the relationship between lens focus and detected current necessarily dependents on the size of the detector cell.
Because Riedesel teaches repeatedly adjusting the secondary beam focusing lens through a feedback loop to optimize detector collection and crosstalk, in light the teaching of Wang, it would have been obvious for an ordinary skilled person in the art, before the effective time of filing, to implement the detector of Riedesel as a pixelated detector whose size is configurable as such the subsequent refocusing performed would also be based on the configured detector cell size, as a known alternative to maximize the current collection within the selected pixels while maintaining acceptable crosstalk.
Claims 5 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Riedesel in view of US 2020/0381207 Al [hereinafter Ren].
Regarding Claims 5 and 18:
Riedesel teaches the system of claim 1 and computer-readable medium of claim 16, respectively. However, Riedesel does not expressly teach wherein the controller is configured to focus the lens to adjust the sizes of the secondary beam spots using a first beam focusing method, and the first beam focusing method comprises one of focusing of the lens to cause paraxial rays of the plurality of secondary charged-particle beams to focus on a plane of the detector; focusing of the lens to position ellipses of least confusion of the plurality of secondary charged-particle beams on the plane of the detector to form the secondary beam spots; or focusing of the lens to minimize rising-edge widths of the secondary beam spots.
Ren teaches wherein the controller is configured to focus the lens to adjust the sizes of the secondary beam spots using a first beam focusing method, and the first beam focusing method comprises focusing of the lens to cause paraxial rays of the plurality of secondary charged-particle beams to focus on a plane of the detector (Figs.3 and 5: Ren discloses a secondary imaging system including zoom lens 151 and projection lens 152 configured to focus secondary beams onto detection elements 140_1~140_3 on detection plane SP3 (para. [0056]). Ren further identifies detection plane SP3 as the image plane of projection lens (para. [0057]). Accordingly, the projection lens establishes its first-order image, formed by the paraxial rays of the secondary beams, on the detector plane).
Therefore, it would have been obvious for an ordinary skilled person in the art, before the effective time of filing, to configure Riedesel’s controller to adjust projection lens so that the paraxial rays of the secondary beamlets focus on detector plane, because focusing paraxial rays at the intended image plane is a conventional first-order focusing condition that concentrates the central portion of each beamlet into a well-defined spot at its corresponding detector region.
Claims 6 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Riedesel in view of US 2005/0035290A1 [hereinafter Saitoh].
Regarding Claims 6 and 19:
Riedesel teaches the system of claim 5 and computer-readable medium of claim 14, respectively. However, Riedesel does not expressly teach wherein the controller is configured to refocus the lens to adjust the currents using a second beam focusing method different from the first beam focusing method, and the second beam focusing method comprises one of: focusing of the lens to cause paraxial rays of the plurality of secondary charged-particle beams to focus on a plane of the detector; focusing of the lens to position ellipses of least confusion of the plurality of secondary charged-particle beams on the plane of the detector to form the secondary beam spots; or focusing of the lens to minimize rising-edge widths of the secondary beam spots.
Saitoh teaches wherein the controller is configured to refocus the lens to adjust the currents using a second beam focusing method different from the first beam focusing method, and the second beam focusing method comprises focusing of the lens to position the ellipses of least confusion of the plurality of secondary charged-particle beams on the plane of the detector to form the secondary beam spots (paras. [0012-0014, 0018, 0037]: Saitoh teaches varying the strength/excitation of the focusing lens and then sets it to the determined focal position. Specially, Saitoh teaches setting the focal position midway between the upper and lower foci, where the beam has its minimum “circle of least confusion” and explains that this midpoint produces a minimum beam cross-section).
Therefore, it would have been obvious for an ordinary skilled person in the art, before the effective time of filing, to configure Riedesel’s controller to employ Saitoh’s least-confusion focusing method when refocusing its lens because Riedesel seeks an optimal secondary electron spot shape and expressly adjusts it focusing elements and stigmators using spot-shape feedback. Applying Saitoh’s known focusing criterion would thus minimize astigmatic blur of the secondary beamlets on detector plane and thereby improving collection efficiency and reducing crosstalk.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JING WANG whose telephone number is (571)272-2504. The examiner can normally be reached M-F 7:30-17:00.
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/JING WANG/Examiner, Art Unit 2881
/DAVID E SMITH/Examiner, Art Unit 2881
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