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 .
Drawings
The subject matter of this application admits of illustration by a drawing to facilitate understanding of the invention. Applicant is required to furnish a drawing under 37 CFR 1.81(c). No new matter may be introduced in the required drawing. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d).
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the term “beam guiding optics”, as mentioned in claims 2 and 18, must be shown or the feature(s) canceled from the claim(s). No new matter should be entered.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Appropriate correction is required.
Specification
The disclosure is objected to because of the following informalities:
The term "signa" is misspelled and should be corrected to "signal" (see para. [0059]).
The term "on-X detector" is misspelled and should be corrected to "on-axis detector" (see para. [0061]).
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION. —The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 7 -20 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claims 7 and 18 all recite “...configured for trespassing of the primary charged particle beam.” The term “trespassing” is too vague and it is unclear how the beam is trespassed. For the purposes of compact prosecution, they will be interpreted as best understood in light of the specification and figures.
Claims 10 and 20 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claims 10 and 20 all recite, “The charged particle beam apparatus according to claim [number], further comprising adjusting the excitation of the intermediate lens to a second mode of operation, comprising: detecting high energy signal electrons…; and collimating low energy signal electrons….” In each case the claim includes both an apparatus and the method steps of using the apparatus, and it is unclear what component, or the apparatus would perform the method steps. Without clarifying amendments, it is unclear whether these intermediate lens excitation adjustment steps describe specific function of claimed parts of the apparatus (e.g., the controller), or are simply intended uses of the preamble recitation of the microscope unit. This ambiguity makes the claims indefinite (See MPEP 2173.05(p)). For the purposes of compact prosecution, they will be interpreted as best understood in light of the specification.
Claim Rejections - 35 USC § 103
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 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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1, 5-8, 11-12, 14-15 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over US 2015/0270095 A1 [hereinafter Kruit] in view of US 2021/0151284 A1 [hereinafter Firnkes].
Regarding Claim 1:
Kruit teaches a method of operating a charged particle beam apparatus (abstract) comprising:
guiding a primary charged particle beam (Fig. 6 (8)) through an opening of an on-axis detector (Fig. 6 (17)), through an intermediate lens (Fig. 6 (13)), through an objective lens (Fig. 6 (14)), and onto a specimen (Fig. 6 (15)), wherein the intermediate lens is disposed between the on-axis detector and the objective lens (see Fig. 6, paras. [0057-0059]);
focusing the primary charged particle beam with the objective lens onto the specimen (paras. [0060&0079]);
in the first mode of operation, detecting low energy signal electrons including secondary electrons with the on-axis detector (para. [0078]); and
in the first mode of operation, detecting the backscattered electrons with a second electron detector (Fig. 6 (12)) upstream of the on-axis detector (Fig. 6, para. [0078]).
However, Kruit does not specifically note that in a first mode of operation, providing an excitation of the intermediate lens to collimate high energy signal electrons including backscattered electrons to the opening of the on-axis detector. In Kruit, high energy signal electrons (backscattered electrons) generated at the specimen travel back through the opening of the on-axis detector 17 and are detected at an upstream detector 12.
Firnkes teaches a secondary charged-particle imaging system (abstract) in which a secondary charged-particle beam 1102 (including backscattered electrons) emerging from the specimen is passed through an intermediate lens system 1610. As shown in Fig. 1 of Firnkes, the intermediate lens system 1610 includes lenses 1612 and 1616, located upstream from an objective lens 7370 shown in Fig. 7 (Fig. 1 shows a partial view of the system, whereas Fig. 7 depicts the complete system, which incorporates the elements illustrated in Fig. 1). Firnkes explains that the electrostatic and/or magnetic excitation of these lenses is actively controlled by a controller 1630 so as to shape the beam 1102, adjust its opening angle, and make the beam more divergent or more convergent as desired in order to improve collection of the beam at detector apertures (see Figs. 1&7 and paras. [0035-0036 and 0043]). In view of Firnkes, it would have been obvious to one of ordinary skill in the art before the effective filing date to implement Kruit’s intermediate lens 13 as such an actively excited intermediate lens system 1610, as taught in Firnkes, and to adjust its excitation so that the high energy signal electrons returning from the specimen are made more collimated, and therefore preferentially guided through the opening of Kruit’s on-axis detector 17 towards the upstream detector 12 ins a first mode of operation, as claimed in claim 1. A person of ordinary skill would have been motivated to do so because the collection efficiency of signal charged particles by detectors can be improved (Firnkes para. [0036]).
Regarding Claim 5:
Kruit in view of Firnkes teach the modified invention of claim 1. Kruit further teaches separating the primary charged particle beam from signal electrons upstream of the on-axis detector (Kruit Fig. 4 and paras. [0071-0072]), wherein the second electron detector is an off-axis detector (Kruit Fig. 5 and paras. [0075-0076]). Detector 411 in Fig. 4 and detector 511 in Fig. 5 of Kruit are described as alternative implementations of the backscatter detector 12 shown in Fig. 6 (upstream of the on-axis detector 17). Detector 411 has holes that let the primary beams pass while the remaining surface intercepts backscattered electrons. Detector 511 is arranged to one side of the optical axis and thus positioned off-axis.
Regarding Claim 6:
Kruit in view of Firnkes teach the modified invention of claim 1, Firnkes further teaches energy filtering signal electrons between the opening of the on-axis detector and the second electron detector (Fig. 1 and para. [0065]: teaches an energy filter may be arranged at the aperture plate 1650, between the first detector 1450 and second detector 1900).
Regarding Independent Claim 7:
Kruit teaches a charged particle beam apparatus (abstract) comprising:
a charged particle beam source (Fig. 6 (4)) configured to generate a primary charged particle beam (Fig. 6 (8)) (see Fig. 6 and para. [0054]);
beam guiding optics configured to guide the primary charged particle beam towards a specimen stage (Fig. 6 (15)) (see Fig. 6 and paras. [0054-0055]);
an on-axis detector (Fig. 6 (17)) having an opening configured for trespassing of the primary charged particle beam (Fig. 6 (8)) (see Fig. 6 and para. [0078]);
a second detector (Fig. 6 (12)) upstream of the on-axis detector (see Fig. 6 and para. [0078]);
an intermediate lens (Fig. 6 (13)) disposed between the on-axis detector and the specimen stage (see Fig. 6);
an objective lens (Fig. 6 (14)) disposed between the intermediate lens and the specimen stage (see Fig. 6).
However, Kruit does not specifically note that the intermediate lens is configured to collimate high energy signal electrons on the opening of the on-axis detector and an energy filter along a signal beam path between the opening of the on-axis detector and the second detector. Instead, Kruit discloses an intermediate magnetic lens 13 disposed between an on-axis detector 17 (with an opening) and an upstream backscatter detector 12, and teaches that high-energy backscattered electrons are limited in acceptance angle and projected onto and through the openings of detector 11 toward the upstream detector (see, Fig. 6 and paras. [0020 & 0058–0060]), thereby defining a signal-electron beam path from the opening of the on-axis detector to the second detector.
Firnkes teaches that the electrostatic and/or magnetic excitation of these lenses is actively controlled by a controller 1630 so as to shape the beam 1102, adjust its opening angle, and make the beam more divergent or more convergent as desired in order to improve collection of the beam at detector apertures (see Fig. 1 and paras. [0035-0036 and 0043]). Firnkes also teaches arranging an energy filter at the aperture 1650 which is between detector 1450 and 1900 (Fig. 1 and para. [0065]). In view of Firnkes, it would have been obvious to one of ordinary skill in the art before the effective filing date to implement Kruit’s intermediate lens 13 as such an actively excited intermediate lens system 1610, as taught in Firnkes, and to adjust its excitation so that the high energy signal electrons returning from the specimen are made more collimated, and therefore preferentially guided through the opening of Kruit’s on-axis detector 17 towards the upstream detector 12 ins a first mode of operation, as claimed in claim 1. A person of ordinary skill would have been motivated to do so because the collection efficiency of signal charged particles by detectors can be improved (Firnkes para. [0036]).
Regarding Claim 8:
Kruit in view of Firnkes teach the modified invention of claim 7. The combined references further teach the charged particle beam apparatus comprising:
a controller (Fig. 1 (1630)) with a processor and a memory storing instructions that, when executed by the processor, cause the charged particle beam apparatus to perform a method of operating the charged particle beam apparatus (Firnkes Fig. 1 and para. [0045]: controller (1630) configured for controlling the excitation of the lens system 1610), the method comprising:
guiding the primary charged particle beam (Fig. 6 (8)) through the opening of the on-axis detector (Fig. 6 (17)), through the intermediate lens (Fig. 6 (13)), through the objective lens (Fig. 6 (14)), and onto a specimen (Fig. 6 (15)), wherein the intermediate lens is disposed between the on-axis detector and the objective lens (Kruit Fig. 6, paras. [0057-0059]);
focusing the primary charged particle beam with the objective lens onto the specimen (Kruit paras. [0060&0079]);
in a first mode of operation, providing an excitation of the intermediate lens to collimate high energy signal electrons including backscattered electrons to the opening of the on-axis detector (Firnkes Figs. 1&7 and paras. [0035-0036 and 0043]).
in the first mode of operation, detecting low energy signal electrons including secondary electrons with the on-axis detector (Kruit para. [0078]); and
in the first mode of operation, detecting the backscattered electrons with a second electron detector upstream of the on-axis detector (see Kruit Fig. 6, para. [0078]).
Regarding Claim 11:
Kruit in view of Firnkes teach the modified invention of claim 7. Kruit further teaches wherein the objective lens is a combined magnetic-electrostatic objective lens (Kruit para. [0044]).
Regarding Claim 12:
Kruit in view of Firnkes teach the modified invention of claim 7. Kruit further teaches wherein the intermediate lens is a magnetic lens (Kruit para. [0057]).
Regarding Claim 14:
Kruit in view of Firnkes teach the modified invention of claim 7, Kruit further teaches a first distance of the on-axis detector is about 100 mm to 300 mm and a second distance of the intermediate lens is about 33.3 mm to 150 mm (see Kruit Fig. 6: teaches an on-axis detector (17) disposed upstream of an intermediate lens (13) along the optical axis). It would be obvious to a person of ordinary skill in the art that the axial “first distance” from the specimen to the on-axis detector is inherently greater than the “second distance” to the immediate lens, as claimed here. The specific numerical ranges (about 100-300mm and about 33.3-150mm) are not described in the specification as critical or producing any particular technical effect. In commercial SEMs, axial spacing relative to the specimen (working distance and detector height) is treated as a normal design/operating parameter selected within a broad range. For example, the TESCAN VEGA3 Manual teaches different preferred specimen-detector distances for SE vs. BSE imaging and provides recommended centering conditions with a working-distance range that the user adjusts depending on the modes (see VEGA3 User Manual, 2014, pp. 17 and 35). Taken together, this shows that SEM designers and users routinely vary these distances to suit packaging and imaging condition. Therefore, in the absence of evidence of criticality, choosing particular absolute values within a workable range for this known geometry would have been an obvious matter of design choice and routine engineering optimization to a person of ordinary skill in the art. See MPEP 2144.04.
Regarding Claim 15:
Kruit in view of Firnkes teach the modified invention of claim 7. Kruit further teaches a beam separator upstream of the on-axis detector (para. [0045]: the detector 411 in Fig. 4 (an alternative implementation of the BSE detector 12 in Fig. 6 which is upstream of the on-axis detector 17) has an array of holes for letting the primary charged particle beam pass through while the remaining surface intercepts the backscattered electrons).
Regarding Independent Claim 18:
Kruit teaches a charged particle beam apparatus (abstract) comprising:
a charged particle beam source (Fig. 6 (4)) configured to generate a primary charged particle beam (Fig. 6 (8)) (See Figs. 1&6 and para. [0054]);
beam guiding optics configured to guide the primary charged particle beam towards a specimen stage (Fig. 6 (15)) (See Figs. 1&6 and paras. [0054-0055]);
an on-axis detector (Fig. 6 (17)) having an opening configured for trespassing of the primary charged particle beam (See Fig. 6 and para. [0078]);
a second detector (Fig. 6 (12)) upstream of the on-axis detector (See Fig. 6 and para. [0078]);
an intermediate lens (Fig. 6 (13)) disposed between the on-axis detector and the specimen stage (See Fig. 6);
an objective lens (Fig. 6 (14)) disposed between the intermediate lens and the specimen stage (See Fig. 6).
the charged particle beam apparatus to perform a method of operating the charged particle beam apparatus (abstract), the method comprising:
guiding the primary charged particle beam through the opening of the on-axis detector (Fig. 6 (17)), through the intermediate lens (Fig. 6 (13)), through the objective lens (Fig. 6 (14)), and onto a specimen (Fig. 6 (15)), wherein the intermediate lens is disposed between the on-axis detector and the objective lens (see Kruit Fig. 6, paras. [0057-0059]);
focusing the primary charged particle beam with the objective lens onto the specimen (Kruit paras. [0060 and 0079]);
in the first mode of operation, detecting low energy signal electrons including secondary electrons with the on-axis detector (Kruit para. [0078]); and
in the first mode of operation, detecting the backscattered electrons with a second electron detector upstream of the on-axis detector (see Kruit Fig. 8, para. [0078]).
However, Kruit does not specifically note a controller and that the intermediate lens is configured to collimate high energy signal electrons on the opening of the on-axis detector, Instead, Kruit discloses an intermediate magnetic lens 13 disposed between an on-axis detector 17 (with an opening) and an upstream backscatter detector 12, and teaches that high-energy backscattered electrons are limited in acceptance angle and projected onto and through the openings of detector 11 toward the upstream detector (see Kruit Fig. 6 and paras.[0020 & 0058]–0060]), thereby defining a signal-electron beam path from the opening of the on-axis detector to the second detector. In addition, Kruit does not specifically note that a controller with a processor and a memory storing instructions that, when executed by the processor and cause the charged particle beam apparatus to perform the method, which includes in a first mode of operation, providing an excitation of the intermediate lens to collimate high energy signal electrons including backscattered electrons to the opening of the on-axis detector.
Firnkes teaches a secondary charged-particle imaging system (abstract) in which a secondary charged-particle beam 1102 (including backscattered electrons) emerging from the specimen is passed through an intermediate lens system 1610. In particular, as shown in Fig. 1, Firnkes teaches:
a controller (Fig. 1 (1630) with a processor and a memory storing instructions that, when executed by the processor and cause the charged particle beam apparatus to perform the method (Fig. 1 and para. [0046).
in a first mode of operation, providing an excitation of the intermediate lens to collimate high energy signal electrons including backscattered electrons to the opening of the on-axis detector (Figs. 1&7 and paras. [0035-0036 and 0043]: the electrostatic and/or magnetic excitation of the intermediate lens system 1610 is actively controlled by a controller 1630 so as to shape the beam 1102, adjust its opening angle, and make the beam more divergent or more convergent as desired in order to improve collection of the beam at detector apertures. In view of Firnkes, it would have been obvious to one of ordinary skill in the art before the effective filing date to implement Kruit’s intermediate lens 13 as such an actively excited intermediate lens system 1610, as taught in Firnkes, and to adjust its excitation so that the high energy signal electrons returning from the specimen are made more collimated, and therefore preferentially guided through the opening of Kruit’s on-axis detector 17 towards the upstream detector 12 ins a first mode of operation, as claimed in claim 1. A person of ordinary skill would have been motivated to do so because the collection efficiency of signal charged particles by detectors can be improved (Firnkes para. [0036]).
Claims 16-17 are rejected under 35 U.S.C. 103 as being unpatentable over US Kruit and Firnkes, further in view of US 6452175 B1 [hereinafter Adamec].
Regarding Claim 16:
Kruit in view of Firnkes disclose the modified invention of claim 7. However, the combination references do not specifically note that the objective lens and the intermediate lens have a common pole piece.
Adamec teaches a charged particle beam column (abstract), wherein the objective lens and the intermediate lens have a common pole piece (see Adamec Fig. 10: upper lens and lower lens share the pole piece 654). Kruit teaches an intermediate lens and an objective lens arranged in series along the optical axis, but shows them as separate lenses. Adamec teaches a two-stage magnetic objective lens in which an upper lens and a lower lens share a common pole piece and thus form a compound lens. It would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to implement Kruit’s immediate lens and objective lens as stages of a common, compound lens sharing a pole piece, as taught by Adamec, in order to shorten the column, improve mechanical alignment, and simplify the magnetic circuit, which are predictable benefits of multi-stage, shared-pole piece designs.
Regarding Claim 17:
Kruit in view of Firnkes disclose the modified invention of claim 7. Adamec further teaches wherein a first distance of one or more first pole pieces of the intermediate lens from an optical axis is larger than a second distance of one or more second pole pieces of the objective lens from the optical axis (see Adamec Fig. 10, Col. 10; Lls. 65-67 & Col, 11; Lls. 1-8: teaches a two-stage lens in which the radical spacing of pole pieces (652 vs. 656) from the optical axis differs between stages). Adamec illustrates that the bore radium/pole-piece distance from the axis is a routine design parameter that can be set differently for successive lens stages. In light of Adamec, it would have been obvious to a person of ordinary skill to select the intermediate lens to have a larger pole distance than the objective lens as one obvious geometric variation of that known design parameter.
Claims 2, 9, 13, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Kruit in view of Firnkes, and further in view of US 2021/0319977 A1 [hereinafter Liu].
Regarding Claim 2:
Kruit in view of Firnkes disclose the modified invention of claim 1. However, the combined references do not specifically note collimating the high energy signal electrons passes high energy signal electrons with a starting angle of 30° or more through the opening of the on-axis detector.
Liu teaches a charged particle beam apparatus that detects backscattered electrons and secondary electrons with different detectors (abstract; Figs. 7A–7B). While Kruit teaches limiting acceptance angle of backscattered electrons to allow passage of certain angular directions of the backscattered electrons (Kruit para. [0020], Liu likewise divides signal electrons into beams (Fig. A -700B2/700B3/700B4) by emission angle and energy (low, medium, and large) and adjusts the field so that large-angle, high-energy beams (700B2) are selectively directed to a given detector. Thus, the art already treats emission/acceptance angle as a result-effective variable that can be chosen to separate “high-angle” electrons from others (para. [0091]). In view of Kruit and Liu, it would have been an obvious matter of routine optimization and design choice for a person of ordinary skill to select a particular numerical boundary within the known high-angle regime (e.g., “30° or more”) to define the large-angle group, absent any showing in the specification that 30° is critical or produces an unexpected technical effect.
Regarding Claim 9:
Kruit in view of Firnkes disclose the modified invention of claim 8. However, the combined references do not specifically note collimating the high energy signal electrons passes high energy signal electrons with a starting angle of 30° or more through the opening of the on-axis detector.
Liu teaches a charged particle beam apparatus that detects backscattered electrons and secondary electrons with different detectors (abstract; Figs. 7A–7B). While Kruit teaches limiting acceptance angle of backscattered electrons to allow passage of certain angular directions of the backscattered electrons (Kruit para. [0020], Liu likewise divides signal electrons into beams (Fig. A -700B2/700B3/700B4) by emission angle and energy (low, medium, and large) and adjusts the field so that large-angle, high-energy beams (700B2) are selectively directed to a given detector. Thus, the art already treats emission/acceptance angle as a result-effective variable that can be chosen to separate “high-angle” electrons from others (para. [0091]). In view of Kruit and Liu, it would have been an obvious matter of routine optimization and design choice for a person of ordinary skill to select a particular numerical boundary within the known high-angle regime (e.g., “30° or more”) to define the large-angle group, absent any showing in the specification that 30° is critical or produces an unexpected technical effect.
Regarding Claim 13:
Kruit in view of Firnkes disclose the modified invention of claim 12. However, the combined references do not specifically note the intermediate lens is an axial gap lens.
Kruit explicitly discloses an intermediate magnetic lens 13. Liu, in turn, teaches that a magnetic lens in an electron-optical column is conventionally implemented as axial-gap pole piece lens (see Liu Fig. 3 and para. [0058]: a magnetic lens 307M comprises a cavity around the primary optical axis 300-1, bounded by the internal surface of the magnetic lens and imaginary planes 307A and 307B, with a polepiece 307P having an opening along the primary optical axis, i.e., a conventional axial-gap magnetic lens configuration). It would therefore have been an obvious design choice to implement Kruit’s intermediate magnetic lens 13 using the same conventional axial-gap magnetic lens structure exemplified by Liu’s 307M, so that the immediate lens is an axial-gap lens as claimed.
Regarding Claim 19:
Kruit in view of Firnkes disclose the modified invention of claim 18. However, the combined references do not specifically note collimating the high energy signal electrons passes high energy signal electrons with a starting angle of 30° or more through the opening of the on-axis detector.
Liu teaches a charged particle beam apparatus that detects backscattered electrons and secondary electrons with different detectors (abstract; Figs. 7A–7B). While Kruit teaches limiting acceptance angle of backscattered electrons to allow passage of certain angular directions of the backscattered electrons (Kruit para. [0020], Liu likewise divides signal electrons into beams (Fig. A -700B2/700B3/700B4) by emission angle and energy (low, medium, and large) and adjusts the field so that large-angle, high-energy beams (700B2) are selectively directed to a given detector. Thus, the art already treats emission/acceptance angle as a result-effective variable that can be chosen to separate “high-angle” electrons from others (para. [0091]). In view of Kruit and Liu, it would have been an obvious matter of routine optimization and design choice for a person of ordinary skill to select a particular numerical boundary within the known high-angle regime (e.g., “30° or more”) to define the large-angle group, absent any showing in the specification that 30° is critical or produces an unexpected technical effect.
Alternatively, Claims 1, 3-4, 7-8, 10, 18 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Kruit in view of US 2021/0319977 A1 Liu.
Regarding Claim 1:
Kruit teaches a method of operating a charged particle beam apparatus (abstract) comprising:
guiding a primary charged particle beam (Fig. 6 (8)) through an opening of an on-axis detector (Fig. 6 (17)), through an intermediate lens (Fig. 6 (13)), through an objective lens (Fig. 6 (14)), and onto a specimen (Fig. 6 (15)), wherein the intermediate lens is disposed between the on-axis detector and the objective lens (see Fig. 6, paras. [0057-0059]);
focusing the primary charged particle beam with the objective lens onto the specimen (paras. [0060&0079]);
in the first mode of operation, detecting low energy signal electrons including secondary electrons with the on-axis detector (para. [0078]); and
in the first mode of operation, detecting the backscattered electrons with a second electron detector (Fig. 6 (12)) upstream of the on-axis detector (see Fig. 6, para. [0078]).
However, Kruit does not specifically note that in a first mode of operation, providing an excitation of the intermediate lens to collimate high energy signal electrons including backscattered electrons to the opening of the on-axis detector.
Liu teaches a charged particle beam apparatus that detects backscattered electrons and secondary electrons with different detectors (abstract; Figs. 7A–7B). The control electrode 714 in Figs. 7A–7B corresponds to control electrode 314 in Fig. 3. As shown in Fig. 3, Liu discloses a compound objective lens 307 including a magnetic lens 307M and an electrostatic lens 307ES formed by control electrode 314 and pole piece 307P (see, e.g., paras. [0058] and [0067]); the compound lens 307 is configured to focus signal electrons (secondary and backscattered) onto signal electron detectors. In the embodiment of Figs. 7A–7B, Liu further explains that adjusting the voltage applied to the control electrode 714 of the electrostatic lens 707ES changes the electric field and thus the trajectories of one or more signal-electron beams, thereby directing selected signal electrons (including backscattered and/or secondary electrons) to different detectors (see Fig. 7B and para. [0092], where applying a second voltage to the control electrode changes the trajectory of backscattered electrons 700B2 so that they are detected by detector 712 after passing through the opening of on-axis detector 713). In view of Liu, it would have been obvious to a person of ordinary skill in the art, before the effective filing date, to incorporate an electrostatic lens analogous to Liu’s 307ES/707ES into the intermediate-lens region of Kruit, such that Kruit’s intermediate magnetic lens 13 and the added electrostatic lens together form a compound intermediate lens similar to Liu’s compound lens 307/707. A POSITA would then adjust the voltage on the control electrode of this electrostatic portion (which forms part of the intermediate lens) to shape and collimate high-energy signal electrons so that they are preferentially guided through the opening of the on-axis detector toward selected detectors. A person of ordinary skill would have been motivated to do so because Liu teaches that separating secondary electrons from backscattered electrons so that they may be detected by different detectors improves the overall detection efficiency (Liu para. [0090]).
Regarding Claim 3:
Kruit in view of Liu teaches the modified invention of claim 1. Liu further teaches adjusting the excitation of the intermediate lens to a second mode of operation, comprising detecting high energy signal electrons with the on-axis detector; and collimating low energy signal electrons to the opening of the on-axis detector (see Liu Fig. 7A and para. [0091]: apply a first voltage signal to the control electrode 714 of the electrostatic lens 707ES to cause secondary electrons (700B4) are detected by an upstream detector (706) after passing through the central opening of the annular on-axis detector (713), while backscattered electrons (700B2) be detected by the on-axis detector (713) itself).
Regarding Claim 4:
Kruit in view of Liu teaches the modified invention of claim 1. Liu further teaches the excitation of the intermediate lens in the second mode of operation is higher as compared to the excitation in the first mode of operation (para. [0090-0092] and [0094-0095]): Liu teaches operating the apparatus in at least two modes in which the excitation of the lens/electrode region is changed so that different energy/angle bands of signal electrons (e.g., high-energy backscattered electrons vs. lower-energy secondary electrons) are collimated along the axis toward an upstream detector or detected at a local on-axis detector). Selecting the mode in which lower-energy signal electrons are collimated upstream (the claimed “second mode”) to use the higher excitation level relative to the mode in which high-energy electrons are collimated (the claimed “first mode”) amounts to a routine optimization of the respective focusing strengths for the different energy bands and would have been an obvious matter of design choice to a person of ordinary skill in the art, without producing any unexpected result or imposing any additional structural limitation beyond the two modes already taught by the prior art.
Regarding Independent Claim 7:
Kruit teaches a charged particle beam apparatus (abstract) comprising:
a charged particle beam source (Fig. 6 (4)) configured to generate a primary charged particle beam (Fig. 6 (8)) (see Figs. 1&6 and para. [0054]);
beam guiding optics configured to guide the primary charged particle beam towards a specimen stage Fig. 6 (15)) (see Figs. 1&6 and paras. [0054-0055]);
an on-axis detector (Fig. 6 (17)) having an opening configured for trespassing of the primary charged particle beam (Fig. 6 (4)) (see Fig. 6 and para. [0078]);
a second detector (Fig. 6 (12)) upstream of the on-axis detector (see Fig. 6 and para. [0078]);
an intermediate lens (Fig. 6 (13)) disposed between the on-axis detector and the specimen stage (see Fig. 6);
an objective lens (Fig. 6 (14)) disposed between the intermediate lens and the specimen stage (see Fig. 6).
However, Kruit does not specifically note that the intermediate lens is configured to collimate high energy signal electrons on the opening of the on-axis detector and an energy filter along a signal beam path between the opening of the on-axis detector and the second detector. Instead, Kruit discloses an intermediate magnetic lens 13 disposed between an on-axis detector 17 (with an opening) and an upstream backscatter detector 12, and teaches that high-energy backscattered electrons are limited in acceptance angle and projected onto and through the openings of detector 11 toward the upstream detector (see, Fig. 6 and paras. [0020 & 0058–0060]), thereby defining a signal-electron beam path from the opening of the on-axis detector to the second detector.
Liu teaches a charged particle beam apparatus that detects backscattered electrons and secondary electrons with different detectors (abstract; Figs. 7A–7B). The control electrode 714 in Figs. 7A–7B corresponds to control electrode 314 in Fig. 3. As shown in Fig. 3, Liu discloses a compound objective lens 307 including a magnetic lens 307M and an electrostatic lens 307ES formed by control electrode 314 and pole piece 307P (see, e.g., paras. [0058] and [0067]); the compound lens 307 is configured to focus signal electrons (secondary and backscattered) onto signal electron detectors. In the embodiment of Figs. 7A–7B, Liu further explains that adjusting the voltage applied to the control electrode 714 of the electrostatic lens 707ES changes the electric field and thus the trajectories of one or more signal-electron beams, thereby directing selected signal electrons (including backscattered and/or secondary electrons) to different detectors (see Fig. 7B and para. [0092], where applying a second voltage to the control electrode changes the trajectory of backscattered electrons 700B2 so that they are detected by detector 712 after passing through the opening of on-axis detector 713). In view of Liu, it would have been obvious to a person of ordinary skill in the art, before the effective filing date, to incorporate an electrostatic lens analogous to Liu’s 307ES/707ES into the intermediate-lens region of Kruit, such that Kruit’s intermediate magnetic lens 13 and the added electrostatic lens together form a compound intermediate lens similar to Liu’s compound lens 307/707. A POSITA would then adjust the voltage on the control electrode of this electrostatic portion (which forms part of the intermediate lens) to shape and collimate high-energy signal electrons so that they are preferentially guided through the opening of the on-axis detector toward selected detectors. A person of ordinary skill would have been motivated to do so because Liu teaches that separating secondary electrons from backscattered electrons so that they may be detected by different detectors improves the overall detection efficiency (Liu para. [0090]).
Regarding Claim 8:
Kruit in view of Liu teach the modified invention of claim 7. The combined references further teach:
a controller with a processor and a memory storing instructions that, when executed by the processor, cause the charged particle beam apparatus to perform a method of operating the charged particle beam apparatus (Liu Fig. 1 and para. [0038]: controller (50)), the method comprising:
guiding the primary charged particle beam (8) through the opening of the on-axis detector (17), through the intermediate lens (13), through the objective lens (14), and onto a specimen (15), wherein the intermediate lens is disposed between the on-axis detector and the objective lens (see Kruit Fig. 6, paras. [0057-0059]);
focusing the primary charged particle beam with the objective lens onto the specimen (Kruit paras. [0060&0079]);
in a first mode of operation, providing an excitation of the intermediate lens to collimate high energy signal electrons including backscattered electrons to the opening of the on-axis detector (see Liu Fig. 7B and paras. [0092];
in the first mode of operation, detecting low energy signal electrons including secondary electrons with the on-axis detector (Kruit para. [0078]); and
in the first mode of operation, detecting the backscattered electrons with a second electron detector upstream of the on-axis detector (see Kruit Fig. 6, para. [0078]).
Regarding Claim 10:
Kruit in view of Liu teach the modified invention of claim 8. Liu further teaches:
adjusting the excitation of the intermediate lens to a second mode of operation, comprising detecting high energy signal electrons with the on-axis detector; and collimating low energy signal electrons to the opening of the on-axis detector (see Liu Fig. 7A and para. [0091]: apply a first voltage signal to the control electrode 714 of the electrostatic lens 707ES to cause secondary electrons (700B4) are detected by an upstream detector (706) after passing through the central opening of the annular on-axis detector (713), while backscattered electrons (700B2) be detected by the on-axis detector (713) itself).
Regarding Independent Claim 18:
Kruit teaches a charged particle beam apparatus (abstract) comprising:
a charged particle beam source (Fig. 6 (4)) configured to generate a primary charged particle beam (Fig. 6 (8)) (See Figs. 1&6 and para. [0054]);
beam guiding optics configured to guide the primary charged particle beam towards a specimen stage (Fig. 6 (15)) (See Figs. 1&6 and paras. [0054-0055]);
an on-axis detector (Fig. 6 (17)) having an opening configured for trespassing of the primary charged particle beam (See Fig. 6 and para. [0078]);
a second detector (Fig. 6 (12)) upstream of the on-axis detector (See Fig. 6 and para. [0078]);
an intermediate lens (Fig. 6 (13)) disposed between the on-axis detector and the specimen stage (See Fig. 6);
an objective lens (Fig. 6 (14)) disposed between the intermediate lens and the specimen stage (See Fig. 6).
the charged particle beam apparatus to perform a method of operating the charged particle beam apparatus (abstract), the method comprising:
guiding the primary charged particle beam through the opening of the on-axis detector (Fig. 6 (17)), through the intermediate lens (Fig. 6 (13)), through the objective lens (Fig. 6 (14)), and onto a specimen (Fig. 6 (15)), wherein the intermediate lens is disposed between the on-axis detector and the objective lens (see Kruit Fig. 6, paras. [0057-0059]);
focusing the primary charged particle beam with the objective lens onto the specimen (Kruit paras. [0060 and 0079]);
in the first mode of operation, detecting low energy signal electrons including secondary electrons with the on-axis detector (Kruit para. [0078]); and
in the first mode of operation, detecting the backscattered electrons with a second electron detector upstream of the on-axis detector (see Kruit Fig. 8, para. [0078]).
However, Kruit does not specifically note that the intermediate lens is configured to collimate high energy signal electrons on the opening of the on-axis detector, Instead, Kruit discloses an intermediate magnetic lens 13 disposed between an on-axis detector 17 (with an opening) and an upstream backscatter detector 12, and teaches that high-energy backscattered electrons are limited in acceptance angle and projected onto and through the openings of detector 11 toward the upstream detector (see Kruit Fig. 6 and paras.[0020 & 0058]–0060]), thereby defining a signal-electron beam path from the opening of the on-axis detector to the second detector. In addition, Kruit does not specifically note that a controller with a processor and a memory storing instructions that, when executed by the processor and cause the charged particle beam apparatus to perform the method, which includes in a first mode of operation, providing an excitation of the intermediate lens to collimate high energy signal electrons including backscattered electrons to the opening of the on-axis detector.
Liu teaches a charged particle beam apparatus (abstract) that is capable of detecting backscattered electrons and secondary electrons with different detectors (see Figs. 7A–7B). The control electrode 714 in Figs. 7A–7B corresponds to control electrode 314 in Fig. 3. As shown in Fig. 3, Liu discloses a compound objective lens 307 including a magnetic lens 307M and an electrostatic lens 307ES formed by control electrode 314 and pole piece 307P (see, e.g., paras. [0058] and [0067]); the compound lens 307 is configured to focus signal electrons (secondary and backscattered) onto signal electron detectors. In particular, Liu teaches:
the intermediate lens is configured to collimate high energy signal electrons on the opening of the on-axis detector (see Liu Fig. 7B and paras. [0092]: apply a second volage to the control electrode 714 of the electrostriction lens 707ES to change the trajectory of the backscattered electrons (700B2), so that the backscattered electrons are detected by detector 712 after passing through the opening of on-axis detector (713));
a controller with a processor and a memory storing instructions that, when executed by the processor and cause the charged particle beam apparatus to perform the method (see Liu Fig. 1 and para. [0038]: controller (50)),
in a first mode of operation, providing an excitation of the intermediate lens to collimate high energy signal electrons including backscattered electrons to the opening of the on-axis detector (see Liu Fig. 7B and para. [0092]: apply a second volage to the control electrode 714 of the electrostatic lens 707ES to change the trajectory of the backscattered electrons (700B2), so that the backscattered electrons are detected by detector 712 after passing through the opening of on-axis detector (713)).
In view of Liu, it would have been obvious to a person of ordinary skill in the art, before the effective filing date, to incorporate an electrostatic lens analogous to Liu’s 307ES/707ES into the intermediate-lens region of Kruit, such that Kruit’s intermediate magnetic lens 13 and the added electrostatic lens together form a compound intermediate lens similar to Liu’s compound lens 307/707. A POSITA would then adjust the voltage on the control electrode of this electrostatic portion (which forms part of the intermediate lens) to shape and collimate high-energy signal electrons so that they are preferentially guided through the opening of the on-axis detector toward selected detectors. A person of ordinary skill would have been motivated to do so because Liu teaches that separating secondary electrons from backscattered electrons so that they may be detected by different detectors improves the overall detection efficiency (Liu para. [0090]).
Regarding Claim 20:
Kruit in view of Liu teach the modified invention of claim 18. Liu further teaches adjusting the excitation of the intermediate lens to a second mode of operation, comprising detecting high energy signal electrons with the on-axis detector; and collimating low energy signal electrons to the opening of the on-axis detector (see Liu Fig. 7A and para. [0091]: apply a first voltage signal to the control electrode 714 of the electrostatic lens 707ES to cause secondary electrons (700B4) are detected by an upstream detector (706) after passing through the central opening of the annular on-axis detector (713), while backscattered electrons (700B2) be detected by the on-axis detector (713) itself).
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 0800-1700 EST.
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/JING WANG/
Examiner, Art Unit 2881
/ROBERT H KIM/Supervisory Patent Examiner, Art Unit 2881