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 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 1, 4 and 11-12 are rejected under 35 U.S.C. 103 as being unpatentable over Testoni (US 7,030,375 B1).
Regarding claim 1, Testoni teaches an electron microscope (semiconductor inspection system, Abstract, fig. 2; SEM spectrometer, col. 5 line 38) for observing a sample (semiconductor device 101) by irradiating the sample with an electron beam the electron microscope comprising:
A pulsed electron emission mechanism (charged particle device 102; implicitly electron beam in an SEM; pulsed, claim 14) configured to emit the electron beam in a pulsed manner;
A detector (118) configured to detect signal electrons emitted from the sample by irradiating the sample with the pulse electron beam;
A timing control unit (implicitly part of computing module 122) configured to control a sampling timing of a detection signal output from the detector while controlling an irradiation parameter of the pulsed electron beam (pulses from electron beam are used as triggers for detector, col. 7 lines 35-52);
A time of flight calculation unit (computing module 122) configured to discriminate the signal electrons according to a time of flight (col. 7 lines 4-16).
Wherein the timing control unit controls the pulsed electron emission to emit the electron beam with a pulse width equal to or less than the time of flight of the signal electrons (pulse is repeated after electrons reach signal detector, col. 7 lines 35-52) which is derived from a flight distance of the signal electrons and energy of the signal electrons (i.e. the distance and energy of the particles are known to determine a time of flight).
Regarding claim 4, Testoni teaches that the sampling of the detection signal generated by a first electron beam is completed in a period (capture window of 100 ns, col. 8 line 47) which may be less than the period from emission of the first electron beam to the second electron beam (beam frequency is in kHz-MHz range, col. 7 lines 51-52).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the invention to ensure that the sampling is completed between the electron pulses in order to prevent overlap of the signal from different pulses and ensure that the time of flight of electrons is properly determined with no unexpected result.
Regarding claim 11, Testoni teaches an objective lens (108) configured to irradiate the sample with the electron beam,
A separator (redirecting lens 110) configured to deflect the signal electrons towards the detector, and
A decelerator (120) configured to decelerate the signal electrons toward the detector; wherein
An electric field for accelerating the signal electrons is formed between the sample and the objective lens (col. 6 lines 17-26).
Regarding claim 12, it would have been obvious to one of ordinary skill in the art on or before the effective filing date of the invention to adjust the pulse width of Testoni to be smaller than a difference between the time of flight of 10 eV and 1 eV electrons, as a matter of routine optimization of a known result-effective variable (the pulse width, as one of ordinary skill in the art would understand that a short pulse width ensures that the particles from a single pulse have approximately the same start time and so simplifies the measurement of time of flight) with no unexpected result.
Claims 3 and 5 are rejected under 35 U.S.C. 103 as being unpatentable over Testoni in view of Junkei (EP 2 390 900 A2).
Regarding claims 3 and 5, Testoni does not teach that the timing control unit controls the sampling timing to start sampling of the detection signal at a timing after a time required for the signal electrons to reach the detector from emission of the electron beam by the pulsed electron emission mechanism, or to start after the pulsed emission mechanism emits the electron beam, sampling of the detection signal from a time point at which the detector initially detects the signal electrons.
Junkei teaches a particle detection system which performs sampling starting when signal particles reach a detector (Abstract, Advantage).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the invention to modify the system of Testoni to activate sampling when signal particles reach a detector (i.e. after a time required for the signal electrons to reach the detector), in order to reduce noise and enhance detection sensitivity by ensuring that only signal particles are detected as described by Junkei.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Testoni in view of Feuerbaum (US 5,041,724 A).
Regarding claim 7, Testoni teaches all the limitations of claim 1 as described above.
Testoni teaches an objective lens (108) configured to irradiate the sample with the electron beam,
The electron microscope further comprising:
A beam separator (redirecting lens 110) configured to deflect the signal electrons toward the detector.
Testoni does not teach that the detector is disposed between the pulsed electron emission mechanism and the objective lens.
However Testoni teaches that the detector is positioned above the objective lens (fig. 2) with a “charged particle device configured to emit a charged particle beam” at the approximate height of the detector just above the beam separator. Feuerbaum teaches an electron column having an electron source with a condenser lens and stigmator above the beam detector.
It would have been obvious to one of ordinary skill in the art at the time of the invention to modify the system of Testoni to have the condenser lens and stigmator of Feuerbaum as part of the charged particle device 102 as these are common elements of an electron beam system that assist in forming the beam. Inserting these elements between the emission mechanism and beam separator would place the electron emission mechanism above the detector of Testoni as required by the claim.
Testoni does not teach that the pulsed electron emission mechanism includes a light source and a photocathode configured to emit electrons by excitation light from the light source.
Feuerbaum teaches a pulsed electron emission mechanism including a light source and a photocathode configured to emit electrons by excitation light from the light source.
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the invention to modify the system of Testoni to have the photocathode of Feuerbaum, as a matter of substituting a known equivalent electron source used in the art capable of creating a fast pulsed beam with no unexpected result.
Claim 1 is rejected under 35 U.S.C. 103 as being unpatentable over Yamaguchi (JP 2007263774 A) in view of Araki (US 20200111638 A1).
Regarding claim 1, Yamaguchi teaches an electron microscope (scanning electron microscope, Abstract, fig. 1) for observing a sample (6) by irradiating the sample with an electron beam the electron microscope comprising:
A pulsed electron emission mechanism (electron gun 11 and chopping coil 15) configured to emit the electron beam in a pulsed manner (intermittent irradiation, p. 3 paragraph 2);
A detector (electron detector 22) configured to detect signal electrons emitted from the sample by irradiating the sample with the pulse electron beam;
A timing control unit (implicitly some means of controlling the pulse timing exists) configured to control an irradiation parameter of the charged particle beam; and
A time of flight calculation unit (time difference detection unit 53 and calculation unit 54) configured to discriminate the signal electrons according to a time of flight, wherein
The timing control unit controls the pulsed electron emission mechanism to emit the electron beam with a pulse width equal to or less than the time of flight of the signal electrons (fig. 3, pulse width is less than time of flight T) which is derived from a flight distance of the signal electrons and energy of the signal electrons (implicitly, the flight distance depends on the distance traveled and energy of the electrons).
Yamaguchi does not teach that the timing control unit controls the sampling timing of a detection signal output from a detector.
Araki teaches a pulsed electron beam device having a timing control unit (control module 131) configured to control a sampling timing of a detection signal output from a detector while controlling an irradiation parameter of the pulsed electron beam (controlling pulse width and detection timing, [0013]) such that the pulse width is equal to or less than the sample timing (fig. 4).
It would have been obvious to one of ordinary skill in the art on or before the effective filing date of the invention to modify the system of Yamaguchi to have the timing control unit control the detector sampling of Araki, in order to ensure proper synchronization between the pulse emission and the detector and make sure that the signal electrons from a given electron beam pulse are detected as described by Araki.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Yamaguchi in view of Araki and in further view of Testoni.
Regarding claim 9, Yamaguchi and Araki teach all the limitations of claim 1 as described above.
Yamaguchi teaches an objective lens (coil 12 for focusing beam on sample) configured to irradiate the sample with the electron beam, wherein
The detector is disposed between a stage on which the sample is placed and the objective lens (fig, 1).
Yamaguchi does not teach that the time-of-flight calculation unit identifies an element of the sample at a position irradiated with the electron beam using the time of flight or the energy of the signal electrons.
Testoni teaches an electron microscope with a time-of-flight calculation unit that identifies an element of the sample at a position irradiated with the electron beam using the energy of the signal electrons (identify composition of area of interest, fig. 4, step 220).
It would have been obvious to one of ordinary skill in the art at the time of the invention to modify the system of Yamaguchi to measure the elements of the sample as described by Testoni, in order to find defects in a semiconductor device in a known manner as described by Testoni (col. 1 lines 31-54).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Yamaguchi in view of Araki and Testoni in further view of Kelly (US 8,575,544 B1).
Regarding claim 10, Yamaguchi, Araki and Testoni teach all the limitations of claim 10 as described above. Yamaguchi, Araki and Testoni do not teach an interface configured to present the identified element of the sample.
Kelley teaches an elemental composition identification system configured to display the identified element of a sample (claim 25).
It would have been obvious to one of ordinary skill in the art at the time of the invention to modify the system of Yamaguchi, Araki and Testoni to display the elemental composition of the substrate, in order to conveniently present the data of the system to the user as described by Kelly.
Allowable Subject Matter
Claims 2, 6, 8 and 13 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: the prior art does not disclose or make obvious an electron microscope system which discriminates electrons according to a time of flight, and an arithmetic nit configured to calculate a surface voltage of the sample by comparing an energy spectrum of the signal electrons detected by the detector with an energy spectrum of the signal electrons when a charging amount of the sample is equal to or less than a reference value.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DAVID E SMITH whose telephone number is (571)270-7096. The examiner can normally be reached M to F 8:30 AM-5:00 PM.
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/DAVID E SMITH/ Examiner, Art Unit 2881