JPWO2014115740A1 - Pattern measuring method, charged particle beam apparatus apparatus condition setting method, and charged particle beam apparatus - Google Patents

Abstract

An object of the present invention is to provide a pattern measuring method and a charged particle beam apparatus that can measure and inspect a pattern formed by the DSA technique with high accuracy. As an embodiment for achieving the above object, a specific polymer is selected from a plurality of polymers that are irradiated with charged particles to form a polymer compound used in the self-organized lithography technology. A pattern measuring method for performing dimension measurement between a plurality of edges of another polymer based on a signal obtained by scanning a charged particle beam in a region including the other polymer after being greatly contracted with respect to the other polymer Alternatively, a charged particle beam apparatus that realizes the measurement is proposed.

Description

  The present invention relates to a pattern measurement method and a charged particle beam apparatus, and more particularly to a pattern measurement method and a charged particle beam apparatus suitable for measuring a polymer compound used in self-organized lithography.

  In recent years, in order to generate a miniaturized pattern in a semiconductor device, formation of an etching mask pattern using a Directed Self-Assembly (DSA) method has been studied. The DSA method utilizes the self-alignment property of a composite polymer material in which two types of polymers are connected or mixed. Patent Document 1 describes an example in which a pattern formed by the DSA technique is observed with a scanning electron microscope, and an example in which a pattern dimension is measured.

  A charged particle beam apparatus capable of measuring and inspecting a fine pattern represented by a scanning electron microscope (SEM) is expected to play an important role in the development of DSA technology. Patent Documents 2 and 3 describe a method of observing a sample after charging the sample and revealing the characteristics of the sample.

  In Patent Document 42, when pattern measurement is performed with an electron microscope, a plurality of image data are integrated to form an image, and whether the number of frames to be integrated can be recognized. A method of automatically determining based on the determination is disclosed.

JP 2010-269304 A (corresponding US Pat. No. 8,114,306) JP-A-10-313027 (corresponding US Pat. No. 6,091,249) JP 2006-234789 A (corresponding US Pat. No. 7,683,319) Japanese Patent Laying-Open No. 2010-092949 (corresponding US Patent Publication US2011 / 0194778)

  In the DSA technique, a high molecular compound in which plural kinds of polymers are chemically bonded is filled between fine patterns formed by a general lithography method, and the polymer is phase-separated by heat treatment. This is a technique for forming a pattern. It is a technology that enables fine patterning beyond the limit of reduction exposure by optical proximity effect (Optical Proximity Effect), but since the surface of the polymer compound after heat treatment is flat, the secondary generated mainly by the edge effect. In the case of a scanning electron microscope that detects electrons, contrast may not be sufficiently obtained. Patent Document 1 discloses a method for observing a pattern formed by the DSA technique using an electron microscope, but does not describe a specific method for improving the contrast. Patent Documents 2 and 3 do not disclose that a pattern formed by the DSA technique is an observation target.

  Hereinafter, a pattern measurement method and a charged particle beam apparatus, which are intended to measure or inspect a pattern formed by the DSA technique with high accuracy using a high contrast image or a signal, will be described.

  Further, when a block copolymer or a blended polymer is applied to a hole pattern serving as a guide formed on the substrate by optical lithography and etching and annealed, the polymer is separated into a cylindrical shape by an induced organization phenomenon. Thereafter, one polymer is removed by development, and hole patterning is completed through an etching process.

  On the other hand, when measuring the pattern separated by annealing using an electron microscope or the like, there is almost no pattern irregularity in the state after induction organization by block copolymer or blended polymer, and it is possible to detect a measurable pattern edge. It is also difficult to measure. It is also difficult to set an appropriate measurement range and irradiation time. In particular, in a semiconductor manufacturing process, in a charged particle beam apparatus that evaluates the quality of a pattern, it is necessary to determine apparatus conditions in advance. Patent Document 1 does not specifically describe how to determine such an apparatus condition. Further, Patent Document 4 discloses a method for automatically determining the number of frames of image data to be integrated. However, how to set apparatus conditions when measuring a pattern with almost no unevenness is specifically described. There is no specific solution stage disclosure.

  On the other hand, the inventors confirmed the phenomenon that a specific polymer contracts by irradiation with a charged particle beam. Usually, among the separated polymers, the polymer that shrinks when irradiated with the beam is the polymer that is removed by development, so if the beam conditions are set appropriately, there is no substantial damage to the sample. In addition, it is possible to perform high-precision measurement for a pattern with unevenness.

  Below, even for patterns that do not have irregularities like DSA patterns and are difficult to measure and inspect by charged particle beam scanning using the edge effect, high-precision pattern measurement and inspection based on appropriate device condition settings An apparatus condition setting method for a charged particle beam apparatus and a charged particle beam apparatus which are to be performed for the second purpose will be described.

  As one aspect for achieving the first object, a polymer compound used in the self-organized lithography technique is identified below among a plurality of polymers that form charged polymer particles by irradiating charged particles. Between a plurality of edges of the other polymer based on a signal obtained by scanning a charged particle beam in a region containing the other polymer after the polymer is greatly contracted with respect to the other polymer or in combination with the contraction. A pattern measuring method for measuring the size of the above or a charged particle beam apparatus for realizing the measurement is proposed.

  Furthermore, as one aspect for achieving the second object, charging when forming an image based on charged particles obtained by scanning a charged particle beam on a polymer compound used in the self-organized lithography technique is performed. An apparatus condition setting method for a charged particle apparatus for setting a particle beam scanning condition, wherein the polymer compound is scanned with a charged particle beam and an image obtained based on the scanning is evaluated, and the evaluation Until the result satisfies a predetermined condition, scanning of the charged particle beam and evaluation of the image are repeated, and the scanning condition when the image satisfies the predetermined condition is determined as the charged particle before scanning for accumulating image acquisition. An apparatus condition setting method for a charged particle beam apparatus that is set as a beam scanning condition is proposed.

  In addition, a scanning deflector that scans a charged particle beam emitted from a charged particle source, a detector that detects charged particles obtained by scanning the charged particle beam with respect to a sample, and an output obtained by integrating the outputs of the detector A charged particle beam device including a control device for forming an image, wherein the control device evaluates an image obtained based on scanning of the charged particle beam, and the charge results until the evaluation result satisfies a predetermined condition. The scanning of the particle beam and the evaluation of the image are repeated, and the scanning condition of the charged particle beam when the evaluation result satisfies the predetermined condition is set as the scanning condition of the charged particle beam before scanning for accumulating image acquisition A charged particle beam device is proposed.

  The above irradiation conditions are for contraction of a specific polymer before acquisition of an image signal used for image formation for performing measurement or inspection, for example, and after the specific polymer is contracted, the beam for measurement or inspection Scanning or image acquisition is executed.

  According to the first configuration, even with a polymer compound in which a plurality of polymers with flat surfaces are bonded, high-precision measurement using a high contrast signal is possible.

  Further, according to the second configuration, even if the pattern has no unevenness like the DSA pattern and is difficult to measure or inspect by charged particle beam scanning using the edge effect, it is based on appropriate apparatus condition setting. High-precision pattern measurement and inspection are possible.

The figure which shows an example of the pattern produced by DSA method. The figure which shows the outline | summary of a scanning electron microscope. The figure which shows the relationship between the cross section of a DSA pattern, and a SEM image. The figure which shows the relationship between the cross section of a DSA pattern, and the SEM image formed based on the output of an oblique detector. The figure which shows four diagonal detectors. The figure which shows the oblique detector which consists of a detection element divided | segmented into 4 elements. The figure which shows an example of the scanning electron microscope provided with the electron source for a process. The figure which shows an example of a planar electron source. The figure which shows the example of arrangement | positioning of a planar electron source. The figure which shows the example of arrangement | positioning of a planar electron source. The figure which shows the example of arrangement | positioning of a planar electron source. The figure which shows an example of the scanning electron microscope provided with the planar electron source. The figure which shows the track | orbit of an electron when a processing beam is irradiated. The flowchart which shows the process from the process of a DSA pattern to the measurement of a DSA pattern. The figure which shows an example of the GUI screen for setting a preliminary irradiation condition. The figure which shows the example of a table which memorize | stores the preliminary irradiation conditions according to the kind of pattern provided for every preliminary irradiation purpose. The figure which shows an example of the pattern dimension measurement system containing a scanning electron microscope. The figure which showed the outline of the scanning electron microscope. The figure which shows an example of the DSA hole pattern image with a guide pattern. A frame image showing how guide patterns and DSA hole patterns are visualized when irradiated with an electron beam. The figure which shows the difference image of the frame image before and behind. The graph which plotted the evaluation value calculated | required from the frame image group of FIG. The graph which plotted the evaluation value calculated | required from the difference image group of FIG. The flowchart which shows the measurement process using an integration image. The figure which shows the example of an image which accumulated the difference image. The figure explaining the method of detecting the hole pattern center using a template. The figure explaining the detection method of a guide pattern. The figure which shows an example of the GUI screen for inputting a measurement parameter.

  FIG. 1 schematically shows a fine pattern by the DSA method. FIG. 1A shows a silicon wafer 101 serving as a pattern generation substrate. In FIG. 1B, a wide pitch pattern 102 that is wider than the repetitive pitch of a desired fine pattern is generated on 101 by lithography. Thereafter, the composite polymer material 110 is applied in FIG. By appropriate heat treatment (annealing), 110 self-aligns in a specific direction using the pattern 102 as a guide. 110 is constituted by repetition of two different types of polymers 111 and 112. In FIG. 1D, by selectively removing one polymer (for example, 112), a narrow pitch pattern 103 having a narrower pitch than the guide pattern 102 can be generated.

  It is important to determine whether or not phase separation is properly performed after heat treatment and before etching in order to quickly know whether an appropriate polymer material has been selected or whether the annealing conditions are appropriate. As illustrated in FIG. 1C, the surface is flat even though the polymer material contains a plurality of polymers, so that a high-contrast image can be obtained with a scanning electron microscope. Absent. Based on the above situation, the inventors have newly found that one of the configurations that should be provided in the SEM that performs inspection and measurement of the DSA pattern is a surface treatment for contrast enhancement. In pattern measurement and inspection, it is important to detect pattern defects as early as possible in order to reduce time and economic costs. In the stage shown in FIG. 1C, the steps shown in FIG. It is preferable to carry out. In this state, there is no difference in height between the polymer 111 and the polymer 112, and normal SEM observation is difficult. Furthermore, there is no great difference in the mass density of the polymer 111 and the polymer 112, and contrast using the difference in mass density cannot be obtained. In addition, the electrical characteristics of the polymer 111 and the polymer 112 are often insulators, and a potential contrast using a charged potential difference cannot be obtained.

  In the embodiments described below, there are provided a method and an apparatus for performing observation after irradiating an observation region with a charged particle beam in advance for observing a narrow pitch pattern generated by the DSA method. By irradiating a region to be observed with a charged particle beam in advance, one of the pair of polymers (111 and 112 in FIG. 1) can be reduced in volume. By this method, it becomes possible to form a step according to the pattern shape on the polymer surface, and highly accurate measurement / inspection can be performed. In addition, one feature is that the charged particle beam with which the observation region is irradiated in advance is the same as the charged particle beam used for the subsequent observation.

  An example of a scanning electron microscope that enables high-contrast signal measurement of a DSA pattern based on a high-contrast signal will be described with reference to the drawings. FIG. 2 shows a schematic diagram of a scanning electron microscope (SEM). The electron source 201 is held at a negative potential with respect to the sample by the control power source 231. The extraction electrode 202 is set to a positive potential with respect to the electron source 201 by the positive voltage power source 232 superimposed on the control power source 231 and extracts the electron beam 220. The electron beam 220 is irradiated onto the observation sample 210 through the focusing lens 203 and the objective lens 208. The diameter of the electron beam 220 on the observation sample 210 is appropriately controlled by the lens control circuits 233 and 238. Further, the current amount of the electron beam 220 is detected by the Faraday cup 205 and measured by the current measuring means 235. The electron beam 220 is scanned in the observation field by the deflector 207 operated by the deflection control circuit 237. When retracting the electron beam 220 from the sample 210, the blanker 204 is operated using the blanker power source 234. Signal electrons generated from the sample 210 are detected by an in-lens detector 206 installed closer to the electron source 201 than the objective lens 208 or an oblique detector 209 installed in a specific direction. The in-lens detector efficiently detects low-speed signal electrons emitted from the sample in various directions, thereby providing a detector suitable for acquiring an edge contrast image that emphasizes the edge portion of the surface step. On the other hand, the oblique detector 209 is suitable for detecting high-energy signal electrons emitted in a specific direction of the sample.

  In observing a pattern created by the DSA method, the observation sample 210 is placed on the sample stage 211 and conveyed below the objective lens 208. The observation site is scanned with the electron beam 220 in advance, and one polymer is reduced in volume to form a surface step. This process is called irradiation for processing. Then, the observation site is scanned again with the electron beam 220, and the signal of the in-lens detector 206 is imaged by the signal processing device 236 to obtain a microscope image. At this time, if irradiation for processing is sufficient, a step is formed at the edge portion of the pattern by the DSA method, and a clear edge contrast appears at the boundary between the two types of polymers in the obtained microscopic image. By using this edge line, high-precision measurement of the pattern dimension on the sample to be observed or defect inspection of the pattern shape on the sample to be observed can be performed.

  The polymer compound used in the self-organized lithography technique is irradiated with charged particles to form a polymer compound, and after a specific polymer is significantly contracted with respect to another polymer, the polymer compound is used. Based on the signal obtained by scanning the charged particle beam in the region containing the other polymer, the above-described configuration in which the dimension measurement between the plurality of edges of the other polymer is performed allows high-precision evaluation of the DSA pattern to be performed quickly. Can be done.

  FIG. 17 is a diagram illustrating an example of a pattern measurement system including an SEM 1701. The system mainly includes an SEM 1701, a control device 1702 that controls the SEM 1701, and an optical condition setting device for setting desired device conditions in the control device 1702. 1703. And a setting device 1704 for setting measurement conditions by SEM. For example, a GUI (Graphical User Interface) screen illustrated in FIG. 15 can be displayed on the display device provided in the setting device 1704. The GUI screen illustrated in FIG. 15 is provided with an input window 1501 for inputting a type of pattern (Pattern) and an input window 1502 for inputting a beam irradiation condition before beam scanning for measurement. . In the case of this example, potential contrast (Voltage Contrast), contact hole observation (Contact Hole (C / H) Observation), edge enhancement that reduces the volume of one polymer described above and emphasizes the edge of the other polymer ( The pre-scan mode can be selected from the three types of edge enhancement.

  In preliminary scanning in the potential contrast mode, beam scanning is performed by beam conditioning for charging elements included in the field of view (first scanning mode). In the preliminary scanning in the contact hole observation mode, beam scanning is performed to positively charge the resist on the sample surface (second scanning mode). In the preliminary scan in the edge enhancement mode, a scan for reducing one polymer is performed (third scan mode).

  Of these three scanning modes, only the third scanning mode is a scanning mode that is not intended to charge the sample. In this embodiment, a GUI screen provided with a window for setting such preliminary irradiation conditions for DSA pattern measurement will be described.

  As described above, there are various types of pre-scans and beam conditions are different. For example, as shown in FIG. 16, a database for storing beam conditions for each pattern type is prepared for each scan mode. If the beam condition can be read based on the pattern type and the scanning mode, the preliminary scanning condition can be easily selected. If such a database is prepared and the conditions when an unknown sample is measured are updated, it is possible to easily set past setting conditions. The field of view size (FOV (Field Of View)), irradiation time (Exposure Time), beam current (Beam Current), and arrival energy of the beam to the sample (Landing) in the GUI screen illustrated in FIG. The database shown in FIG. 16 may be updated by selecting the number of energy) and the number of frames, selecting the type of pattern, and selecting the preliminary scanning mode.

  The database is registered in a memory 1705 built in the optical condition setting device 1703, and is set as an optical condition of the SEM 1701 by setting by the setting device 1704. An arithmetic processing unit 1706 provided in the optical condition setting device 1703 has an optical condition setting unit 1707 for setting beam conditions for measurement, a database registered in the memory 1705, or a setting set by the setting device 1704. Based on the conditions, a preliminary irradiation condition setting unit 1708 for setting preliminary scanning conditions, a luminance condition extraction unit 1709 for obtaining conditions for stopping preliminary irradiation, which will be described later, and a profile waveform are formed based on beam scanning for measurement. A pattern measuring unit 1710 for measuring the dimension of the pattern is included.

  According to the configuration as described above, it is possible to perform the measurement using the edge that has become apparent based on the processing with high accuracy.

  FIG. 3 is a diagram showing the relationship between the cross section of the DSA pattern and the SEM image. In FIG. 3a, it is the DSA pattern and SEM image before the irradiation implementation for a process. Corresponding to the fact that there is no surface step between the two types of polymers 301 and 302, there is no contrast in the SEM image. FIG. 3b shows a case where the volume of the polymer 302 is reduced by beam irradiation. Many signal electrons are generated from the side wall of the polymer 301 that is not reduced in volume, and a clear strong signal region (white band) 303 is formed at the boundary between the polymer 301 and the polymer 302. As a result, the DSA pattern can be measured and inspected. FIG. 3c shows the case where the method of the invention is used but the volume reduction is insufficient. In this case, the amount of signal electrons from the side wall of the polymer 301 is not sufficient, and the white band 304 is also weak. More specifically, compared to the edge 305 in contact with the portion not filled with the polymer 302 at the extreme end, the pattern edge 304 that is insufficiently processed than the white band 303 of the pattern edge that has been sufficiently processed. It can be seen from the enlarged view of the pattern in FIG.

  In particular, in the case of an unknown sample, in order to ensure sufficient measurement accuracy, it is desirable to adopt a method for determining whether irradiation for processing is sufficient.

  FIG. 14 is a flowchart showing steps from processing to measurement. The following processing is executed by the control device 1702 controlling the SEM 1701 based on the setting conditions set by the optical condition setting device 1703. First, beam scanning for confirming whether or not processing and processing are performed properly is performed (step 1401), and a profile for processing state monitoring is formed (step 1402). Here, the luminance of the edge portion is monitored, and the luminance difference between the peak top and the peak bottom is determined (step 1403). If the value is less than the predetermined value, the process returns to step 1401. If the value is equal to or greater than the predetermined value, a beam scan for dimension measurement is performed (step 1404). A profile is formed based on the charged particles obtained as a result of the beam scanning in step 1404 (step 1405), and pattern dimension measurement is performed using the formed profile (step 1406).

  Unlike the case where a specific element is selectively charged, the luminance signal of the edge and the other part becomes relatively different as the preliminary irradiation progresses. It is possible to obtain an appropriate processing end point by evaluating the transition of each difference. In addition, the luminance information is not a comparison of peak heights, and for example, a change in peak width may be evaluated. Note that a profile formed for dimension measurement does not include a profile signal for processing monitoring, thereby enabling highly accurate dimension measurement.

  As will be described later, when charged particle detection for processing monitoring and charged particle detection for pattern dimension measurement are performed at the same time, a signal after processing is selectively used when forming a measurement profile. Alternatively, the output signal of the detector may be received after the processing is completed.

  FIG. 4 is a diagram showing an image formed based on charged particles detected by an oblique detector 209 arranged in the oblique direction with respect to the beam optical axis on the same observation target as that in FIG. In the image by the oblique detector 209, the sample inclined surface with the normal direction directed toward the detector is bright, and the sample surface with the normal direction directed opposite to the detector is imaged dark. In other words, an edge having a cross section facing the detector side becomes bright, and an edge having a cross section facing the detector side is dark.

  FIG. 4a is an SEM image of the DSA pattern before beam irradiation for processing. Since there is no surface level difference between the two types of polymers 401 and 402, no contrast is obtained even if the SEM image is based on detection by an oblique detector. 4b and 4c are SEM images when the volume of the polymer 402 is reduced by processing by beam irradiation.

  Of the side walls of the polymer 401 that do not shrink in volume, the side wall portion facing the oblique detector and a part of the polymer 402 are brightly imaged, and the opposite side wall and a part of the polymer 402 are imaged darkly. In FIG. 4, the brightness 403 of the upper part of the polymer, the brightness 404 of the cross section facing the detector side when the processing is sufficiently performed, and the direction opposite to the detector side when the processing is sufficiently performed The brightness 405 of the cross-sectional portion, the brightness 406 of the cross-sectional portion facing the detector side when processing is insufficient, and the brightness 407 of the cross-sectional portion facing the direction opposite to the detector side when processing is insufficient, Expressed in different display formats.

  The larger the brightness difference between the bright and dark parts, the deeper the surface step, and the smaller the brightness difference, the shallower the surface step, so use the image of the oblique detector to determine whether irradiation for processing is sufficient. can do. More specifically, the control device forms a histogram with the horizontal axis representing the luminance and the vertical axis representing the number of detections based on the signal output of the oblique detector arranged in a specific direction, and has a predetermined luminance. It is conceivable to determine that the processing has been completed when the luminance difference between the two peaks exceeds a predetermined value. Further, since the cross section facing the detector becomes brighter as the processing progresses, it may be determined that the processing is completed when the luminance of the edge portion on the detector side becomes equal to or higher than a predetermined value. However, since the brightness of the edge part varies depending on the shape of the cross section and the material of the polymer, the method of determining based on the relative ratio of the brightness of the dark part and the bright part can detect the end of processing with higher accuracy. It becomes possible.

  By detecting the end of machining with high accuracy, it is possible to realize high-accuracy measurement without increasing the measurement time and excessive beam irradiation. Further, by providing a measurement detector and a processing monitor detector separately, it is possible to immediately shift to measurement after processing.

  In the above processing amount determination, it is assumed that the side wall direction of the pattern does not always coincide with the direction of the oblique detector. As the oblique detector, a plurality of oblique detectors corresponding to different directions may be installed. FIG. 5 shows an example in which oblique detectors that are independent in four directions are arranged. Signal electrons 501a, 501b, 501c, and 501d generated from the sample 210 by the electron beam 220 are detected by the oblique detectors 502a, 502b, 502c, and 502d, respectively, according to the emission direction. Alternatively, detection elements (semiconductor detectors, multichannel plates, avalanche photodiodes, CCDs) obtained by dividing a plurality of detectors each having a single detection surface may be used. FIG. 6 shows an example of an oblique detector in which detection elements divided into four elements are arranged. The signal electrons are detected by any one of the elements 601a, 601b, 601c, and 601d according to the emission direction.

  Furthermore, in order to perform irradiation for processing more efficiently, the lens control circuit 233 or 238 can be used to change the diameter on the sample to be different from the electron beam at the time of observation. It is also possible to irradiate with an energy different from the electron beam at the time of observation. Similarly, the current amount, the scanning speed, the scanning area, and the like can be set differently from the observation time in order to efficiently perform the processing.

  In the description so far, the description has been mainly made on the processing before measurement using the beam for measurement or the beam condition of the beam for measurement. However, the measurement beam is described below. An example in which a beam source different from this beam source is provided in the charged particle beam apparatus and processing is performed using the different beam source will be described.

  In this embodiment, an example will be described in which a processing beam source is formed in parallel along the sample surface so as to irradiate the processing beam from a direction perpendicular to the sample surface. In order to provide the processing beam source in the charged particle beam apparatus, it is necessary to arrange the beam source at a position other than the beam trajectory emitted from the measurement beam source. For example, if the processing beam source is disposed at an oblique position with respect to the beam trajectory of the measuring beam, the beam is irradiated from an oblique direction with respect to the sample surface. There is a possibility that inspection and measurement errors will occur.

  In addition, in order to irradiate a beam perpendicular to the observation site, it is conceivable to deflect the beam introduced from an oblique direction to the observation site by bending it with a deflector, but a deflector for bending is generally used for observation. In order to generate aberrations in the electron beam, when surface treatment and observation are performed simultaneously, the resolution is degraded. Degradation of resolution may reduce the measurement accuracy of narrow pitch pattern measurement.

  Further, if another electron source such as a flood gun is provided, the vacuum chamber may be enlarged.

  In the present embodiment, a configuration in which the first charged particle beam used for observation is not the same as the second charged particle beam irradiated on the observation region in advance will be mainly described. An example in which the observation with the first charged particle beam and the irradiation with the second charged particle beam are performed simultaneously will also be described. Furthermore, the first charged particle beam emission source (first charged particle beam source) includes the second charged particle beam emission source (second charged particle beam source) and its particle beam optical axis. An example of the same will be described.

  By making the optical axis the same, it is possible to irradiate and process charged particles evenly with respect to a narrow pitch pattern, and processing and observation can be performed without moving the sample, so the vacuum chamber is downsized. it can. Further, the beam emitted from the processing beam emission source is perpendicular to the sample surface, and the processing beam and the measurement beam are coaxial, so that processing and measurement without degradation in resolution due to deflection of the deflector are performed. It becomes possible to do.

  According to the present embodiment, it is possible to provide a charged particle beam apparatus capable of recognizing a molecular boundary with high visibility even when the molecular polymer array is formed by the DSA method and has no difference in mass density. it can. In addition, the volume of the polymer can be reduced efficiently and uniformly in a short time while maintaining the resolution, and high-precision inspection / measurement of fine patterns becomes possible.

  Hereinafter, specific examples of the present embodiment will be described with reference to the drawings. FIG. 7 shows a schematic diagram of a scanning electron microscope (SEM). The electron source 701 is held at a negative potential with respect to the sample by a control power source 731. The extraction electrode 702 is set to a positive potential with respect to the electron source 701 by the positive voltage power source 732 superimposed on the control power source 731 and extracts the electron beam 720. The electron beam 720 is irradiated onto the observation sample 710 through the focusing lens 703 and the objective lens 708. The diameter of the electron beam 720 on the observation sample 710 is appropriately controlled by the lens control circuits 733 and 738. Further, the amount of current of the electron beam 720 is detected by the Faraday cup 705 and measured by the current measuring means 735. The electron beam 720 is scanned in the observation field by a deflector 707 operated by a deflection control circuit 737. When retracting the electron beam 720 from the sample 710, the blanker 704 is operated using the blanker power source 734. The signal electrons generated from the sample 710 are detected by the detector 706 and imaged by the signal processing device 736 to obtain a microscopic image.

  A planar electron source 709 is disposed between the sample 710 and the objective lens 708, and its operation is controlled by a control power source 739. The planar electron source exclusively irradiates the DSA pattern for processing. The planar electron source 709 shares an optical axis with the electron source 701 for observation. FIG. 8 shows a specific form of the planar atomic source 709 arranged coaxially.

  The planar electron source 709 has an annular shape having a disk shape and a hole in the center. In particular, since the central hole and the electron beam 720 have a common axis, it is considered that the two electron sources 709 and 701 are arranged coaxially. Since it is sufficient that the vicinity of the observation site of the sample 710 can be uniformly processed, even if the outer diameter portion of the planar electron source 709 is other than circular, the characteristics of the present invention are not impaired. As shown in FIG. 8, the planar electron source 709 includes an emission surface 802 and a lead surface 803. The control power source 739 includes a high voltage power source 805 that determines an acceleration voltage of the planar electron source 709, and a high voltage power source 806 that determines a potential difference between the extraction surface 803 and the emission surface 802 and extracts an electron beam.

  In the configuration of FIG. 7, most of the signal electrons generated from the sample are blocked by the planar electron source 709, and the number of electrons reaching the detector 706 is small. In this case, as shown in FIG. 9, an oblique detector 901 may be installed outside the planar electron source 709. In particular, as described in the first embodiment, the detection of the edge portion of the observation pattern by the oblique detector is important, and therefore the oblique detector 901 can be used as a main detector.

  Alternatively, as shown in FIG. 10, the planar electron source 709 may be installed closer to the electron source 701 than the objective lens 708 and the detector 706. With this configuration, efficient detection of the signal electrons 1001 can be realized. In this case, the angle at which the on-surface electron source 709 looks at the sample 710 is narrowed, and the amount of irradiated electrons may be reduced. It is necessary to efficiently guide the irradiation current from the planar electron source 709 to the sample 710 by the objective lens 708 or a lens added separately.

  Alternatively, as shown in FIG. 11, a configuration in which the planar electron source 709 is arranged so that the height of the planar electron source 709 is the same as the focal point 1102 of the signal electrons 1101 is also possible. The focal point 1102 is sufficiently small and can pass through the central hole of the planar electron source 709. By this method, the planar electron source 709 can be disposed closer to the sample 708 than the detector 709, and the irradiation current can be efficiently guided to the sample 710.

  Further, other embodiments will be described with reference to the drawings. FIG. 12 shows a schematic diagram of a scanning electron microscope (SEM). The electron source 1201 is held at a negative potential with respect to the observation sample 1211 by the control power supply 1231. The potential of the electron source 1201 with respect to the sample 1211 is VP (<0). The extraction electrode 1202 is set to a positive potential VP1 with respect to the electron source 1201 by the positive voltage power source 1232 superimposed on the control power source 1231, and extracts the electron beam 1220. The electron beam 1220 is irradiated onto the sample 1211 through the focusing lens 1203 and the objective lens 1208. The diameter of the electron beam 1220 on the observation sample 1211 is appropriately controlled by the lens control circuits 1233 and 1238. Further, the current amount of the electron beam 1220 is detected by the Faraday cup 1205 and measured by the current measuring means 1235. The electron beam 1220 is scanned in the observation field by a deflector 1207 operated by a deflection control circuit 1237. When retracting the electron beam 1220 from the sample 1211, the blanker 1204 is operated using the blanker power source 1234.

  Signal electrons generated from the sample 1211 are detected by an in-lens detector 1206 installed on the electron source 1201 side of the objective lens 1208 or an oblique detector 1214 installed in a specific direction, and a signal processing device 1236 or 1244 is detected. To obtain a microscopic image. An energy filter 1213 is disposed between the oblique detector 1214 and the sample 1211. The threshold voltage of the energy filter 1213 is controlled by the high voltage power supply 1243.

  A planar electron source 1209 is disposed between the sample 1211 and the objective lens 1208. The potential of the planar electron source 1209 is controlled by the control power source 1239. The potential of the planar electron source 1209 with respect to the sample 1211 is VF. Further, the planar electron source 1209 has a mesh-shaped extraction surface 1210. In this lead-out surface 1210, the potential VF1 of the lead-out surface 1210 with respect to the planar electron source 1209 is controlled by a high-voltage power source 1240 superimposed on the control power source 1239. The electron beam irradiated from the planar electron source 1209 to the sample 1211 exclusively irradiates the DSA pattern for processing. In principle, it is also possible to install a blanker between the planar electron source 1209 and the sample 1211 when the sample 1211 is not irradiated from the planar electron source 1209. However, since the irradiation area is large and it is difficult to deflect the electron beam with a blanker, the potential difference VF is made sufficiently small or positive to reduce the number of electrons reaching the sample, or the potential difference VF1 is made sufficiently small. Alternatively, a method of reducing the number of electrons emitted from the planar electron source 1209 to a negative value is used.

  Next, a method of simultaneously performing electron beam irradiation for processing by the planar electron source 1209 and acquisition of an SEM image will be described using FIG. FIG. 13 shows details of the planar electron source and the oblique detector shown in FIG. It is not always necessary to use an oblique detector, and an in-lens detector 1206 can be implemented with a similar configuration.

  When irradiation for processing and acquisition of an SEM image are performed simultaneously, not only the electron beam 1220 but also the electron beam 1303 irradiated for processing generates signal electrons 1304 from the sample 1211. The spatial resolution of the SEM image is determined by the diameter of the electron beam 1220 on the sample 1211. Since the spatial extent of the electron beam 1303 for processing is sufficiently larger than the diameter of the electron beam 1220, the signal electrons generated by the electron beam 1303 for processing cannot give high spatial resolution, and both electrons If the signal electrons generated by the lines are detected simultaneously, the resolution of the SEM image is degraded. In order to avoid this problem, the potential VP of the electron source 1201 is set to be more negative than the potential VF of the planar electron source 1209 (VP <VF).

  Accordingly, the kinetic energy that the electron beam 1220 for observation has when entering the sample 1211 is larger than the kinetic energy that the electron beam 1303 for processing has when entering the sample 1211. Therefore, the maximum energy EP of the signal electrons generated by the electron beam 1220 for observation is always larger than the maximum energy EF of the signal electrons generated by the electron beam 1303 for processing (EP> EF).

  Next, if the threshold voltage Eth of the energy filter 1213 is selected such that EP> Eth> EF, the filtered signal electrons 1305 detected by the oblique detector 1214 are the electron beam for observation. It is composed only of electrons generated by 1220. By the above method, processing and observation can be efficiently performed simultaneously without deteriorating the image quality.

  The embodiment described below relates to a charged particle beam apparatus that mainly scans a charged particle beam on a sample pattern to inspect and measure the sample. The sample pattern to be observed is a contact hole or via pattern in which a block copolymer and a blended polymer are formed in a guide pattern by induction organization.

  In a general semiconductor device, a circuit pattern is formed over a plurality of layers. Vias and contact holes are formed to connect the circuit patterns of these layers. Vias and contact holes are used for various connections such as underlying transistors and circuit wiring, other elements and circuit wiring, and wiring. In the process of manufacturing a conventional via pattern or contact hole, a method of performing lithography and etching in order at a position and size determined by design data is generally used. With the latest immersion lithography and dry etching, a via pattern of about 30 nm can be formed, but it is becoming difficult to use conventional optical lithography in order to resolve the via pattern after the 22 nm node. Various efforts such as double exposure, super-resolution technology, EUV exposure, and electron beam exposure have been made to address the fundamental problem of miniaturization of semiconductor device patterns. Does not meet the requirements of mass production in terms of level.

  A patterning technique using guided organization with a block copolymer or a blended polymer can form a fine pattern without using an expensive exposure apparatus. In particular, in forming a DSA hole using a hole pattern as a guide, it has become possible to generate a fine hole pattern while controlling the position of the pattern.

  When a block copolymer or blended polymer is applied to a hole pattern serving as a guide formed by optical lithography and etching on a substrate and annealed, the polymer is separated into a cylindrical shape by an induced organization phenomenon. Thereafter, one polymer is removed by development, and hole patterning is completed through an etching process.

  By irradiating a charged particle beam instead of development in a state after induction organization, a polymer component (for example, PMMA) that easily reacts to the charged particle beam is patterned by a shrink phenomenon. Thus, a locally separated DSA pattern image can also be obtained by an inspection apparatus that irradiates a charged particle beam before development.

  From the image thus obtained, the diameter of the DSA hole, the positional deviation between the guide pattern and the formed DSA hole, and the like can be measured and evaluated.

  If there is no problem in the evaluation result, a developing process is performed, and a hole pattern is formed through an etching process. If the evaluation result is not good, rework is performed or the condition of the manufacturing apparatus in the previous process is changed and the pattern is formed again. Thus, the yield and quality of the semiconductor process can be improved by feeding back information obtained by measurement and evaluation of a fine hole pattern using a charged particle beam to a manufacturing apparatus.

  In a charged particle beam apparatus used for inspection of a semiconductor process such as a length measuring SEM, it is necessary to determine the number of scanning frames in advance for automatic operation. In the pattern of the DSA process, the pattern edge can be observed by irradiating an electron beam, but the interaction between the charged particle beam and the polymer component such as a shrink phenomenon is generally unstable, so the number of integrated frames is uniquely determined. Difficult to do. For this reason, it is difficult to detect the pattern position by template matching using the registered template.

  In this method, due to the characteristics of the charged particle beam apparatus, the signal-to-noise ratio is low, and it is difficult to detect the pattern edge by separating the signal and noise with a small number of added signals.

  In the DSA process, as described above, the image is not stable unless the charged particle beam is irradiated for a certain period of time, so that it is difficult to determine the optimum electron beam irradiation time before image acquisition.

  Even when a pattern is detected using a registered template, the pattern observed in the DSA process is likely to change due to irradiation with a charged particle beam, which may cause a positional shift.

  In the DSA process, it is required to measure and monitor the positional deviation between the guide pattern and the formed DSA pattern.

  In the following examples, a charged particle beam is scanned in a state after induced organization by a block copolymer or a blended polymer, and a pattern position is recognized based on information obtained from charged particles emitted from the scanned portion and evaluation criteria. The scanning electron microscope to be measured will be described. In addition, a method of capturing conditions such as the number of integrated frames based on evaluation values by capturing signals and image changes from the pattern of the DSA process by irradiating an electron beam will be described.

  An example in which the measurement range and the pattern position are detected by appropriately using the evaluation value in combination with the signal intensity, the luminance change of the image, the edge sharpness, and the edge continuity will be described.

  An example in which a noise level such as a dispersion value is measured in advance from an image at the initial stage of irradiation with a DSA pattern charged particle beam for the purpose of separating a pattern edge signal and noise and used as an evaluation criterion will be described.

  An example in which the time during which the edge of the guide pattern or the brightness of the DSA pattern is stabilized is determined by capturing a change in the signal or image from the pattern of the DSA process will be described.

  Even when a template is registered and pattern detection is performed, an unstable pattern signal of the DSA process is not used, and a guide pattern image after etching or a pseudo image generated from design data is registered as a template and used for pattern detection. explain.

  According to the said structure, it becomes possible to recognize and measure a pattern position in the state after induction organization by the block copolymer or the blended polymer. In this method, the measurement range is set automatically.

  When imaging the DSA process pattern during automatic operation of the charged particle beam apparatus, an appropriate number of frames and pre-dose time can be determined. Moreover, stable pattern position detection and measurement are possible by using a plurality of evaluation values. Furthermore, by detecting the noise level from the image at the initial stage of DSA pattern charged particle beam irradiation and separating the pattern edge signal and noise, pattern misdetection can be reduced.

  When registering a template and performing automatic operation, it is possible to detect a stable pattern by registering a pseudo-image generated from an etched guide pattern image or design data as a template and using it for pattern detection.

  FIG. 18 is a block diagram of a schematic configuration of a scanning electron microscope. The overall control unit 1825 is configured to transmit the entire apparatus via the electron optical system control device 1826 and the stage control device 1827 based on the acceleration voltage of electrons input from the user interface 1828 by the operator, information on the wafer 111, observation position information, and the like. Control is performed. The wafer 1811 is fixed on a stage 1812 in a sample chamber 1813 after passing through a sample exchange chamber via a sample transfer device (not shown).

  The electron optical system controller 1826 is in accordance with a command from the overall controller 1825, and includes a high voltage controller 1815, a first condenser lens controller 1816, a second condenser lens controller 1817, a secondary electron signal amplifier 1818, an alignment controller 1819, and a deflection. The signal control unit 1822 and the objective lens control unit 1821 are controlled.

  A primary electron beam 1803 extracted from the electron source 1801 by the extraction electrode 1802 is converged by the first condenser lens 1804, the second condenser lens 1806, and the objective lens 1810 and irradiated onto the sample 1811. On the way, the electron beam passes through the diaphragm 1805, its trajectory is adjusted by the alignment coil 1808, and two-dimensionally on the sample by the deflection coil 1809 that receives a signal from the deflection signal control unit 1822 via the deflection signal amplifier 1820. Scanned. Due to irradiation of the primary electron beam 1803 to the wafer 1811, secondary electrons 1814 emitted from the sample 1811 are captured by the secondary electron detector 1807, and a secondary electron image display is performed via the secondary electron signal amplifier 1818. Used as luminance signal for device 1824. Since the deflection signal of the secondary electron image display device 1824 and the deflection signal of the deflection coil are synchronized, the pattern shape on the wafer 1811 is faithfully reproduced on the secondary electron image display device 1824.

  In addition, in order to create an image used for pattern dimension measurement, the signal output from the secondary electron signal amplifier 1818 is AD-converted in the image processor 1823 to create digital image data. Further, a secondary electron profile is created from the digital image data. In the present embodiment, using an arithmetic device such as the image processor 1823, image data to be integrated is selected as described later. In addition, the calculation device and the control unit may be simply referred to as a control device.

  A range to be measured from the created secondary electron profile is selected manually or automatically based on a certain algorithm, and the number of pixels in the selected range is calculated. The actual dimension on the sample is measured from the actual dimension of the observation region scanned by the primary electron beam 1803 and the number of pixels corresponding to the observation region.

  In the above description, a scanning electron microscope using an electron beam has been described as an example of a charged particle beam apparatus. However, the present invention is not limited to this. For example, an ion beam irradiation apparatus using an ion beam may be used. Good.

  FIG. 19 shows a schematic diagram 1900 of a typical pattern image used for DSA hole pattern measurement with a guide pattern. In the schematic diagram 1900 of the DSA hole pattern image, there are four DSA hole patterns (1901, 1902, 1903, 1904) with guide patterns. Hole patterns (1911, 1912, 1913, 1914) serving as guides are generally formed by a lithography process and an etching process using a conventional optical exposure apparatus. Usually, the DSA hole pattern (1921, 1922, 1923, 1924) is inductively textured by applying a block copolymer or a blended polymer and then separating the polymer in an annealing process. Thereafter, one polymer is removed by development, and patterning is completed through an etching process. However, by irradiating an electron beam instead of development after induction organization, a polymer (for example, PMMA) that easily reacts to the electron beam can see the edge of the DSA hole even by the shrink phenomenon. In this way, a DSA pattern image that is locally separated (only inspection points) can be obtained by an inspection apparatus that irradiates an electron beam before development. The block copolymer is described below, but the same applies to the blended polymer.

  FIG. 20 is a schematic diagram showing an image of each DSA hole imaged when a DSA hole pattern coated with a block copolymer is irradiated with an electron beam. A mode in which a guide pattern and a DSA hole pattern gradually appear from an image 2000 before electron beam irradiation (2000, 2010, 2020, 2030, 2040, 2050) is shown. In the image 2000 immediately after the electron beam irradiation, almost no guide pattern or DSA hole can be observed. In the image 2050 sufficiently irradiated with the electron beam, the edge 2052 of the guide pattern hole and the bottom portion 2053 of the DSA hole pattern after the block copolymer is separated can be clearly observed. Here, a figure for each frame image of the hole pattern is shown, but in the case of a line pattern, a signal profile for each line scan may be used. Further, every several images obtained by averaging the frames may be used.

  FIG. 21 is an image obtained by calculating the difference between the preceding and succeeding images in the image for each frame described in FIG. The difference image 2110 is an image obtained by subtracting 2100 from the frame image 2110. Similarly, the difference image 2120 is obtained by subtracting the frame images 2120 to 2110, and the difference image 2130 is obtained by subtracting the frame images 2130 to 2120. The difference image 2150 is obtained by subtracting the frame image 2040 from the frame image 2050, but the luminance value is close to zero. This indicates that there is almost no change between the frame image 2050 and the frame image 2040. In this patent, this change is captured and the number of frames, guide pattern position, and DSA pattern position are detected. As described above, by comparing the plurality of images extracted in the beam scanning process with respect to the same object, it is possible to select an appropriate apparatus condition. A plurality of images obtained by different numbers of frames are basically the same object, that is, an autocorrelation evaluation is performed. For example, it is possible to perform highly accurate evaluation as compared with a case where a reference image is prepared in advance and apparatus conditions are selected based on comparison with the reference image.

  FIG. 22 is a graph 2200 in which evaluation values (for example, pixel dispersion) obtained from the frame image of FIG. 20 are plotted. Plot point 2210 is an evaluation value of image 2000 in FIG. 20, and plot point 2211 is an evaluation value of image 2010. Similarly, the plot point 2212 is the evaluation value of the image 2020, the plot point 2213 is the evaluation value of the image 2030, the plot point 2214 is the evaluation value of the image 2040, and the plot point 2215 is the evaluation value of the image 2050. The evaluation value increases as the pattern becomes gradually clearer when the electron beam is irradiated (2211, 2122), and the change in the evaluation value is saturated when the electron beam is sufficiently irradiated (2213, 2214, 2215). I can see the situation.

  FIG. 23 shows a plot of evaluation values (for example, integrated luminance values) obtained from the difference image in FIG. Plot point 2310 is the evaluation value of image 2110 in FIG. 21, and plot point 2311 is the evaluation value of image 2120. Hereinafter, the plot point 2312 is the evaluation value of the image 2130, the plot point 2313 is the evaluation value of the image 2140, and the plot point 2314 is the evaluation value of the image 2150. Immediately after the start of electron beam irradiation, the change in the image is large, and the evaluation values of the plot points 23610 and 2311 are large. It can be seen that in the latter half of the image change saturation (plot point 2312, plot point 2313, plot point 2314), it gradually converges to a constant evaluation value.

  FIG. 24 shows a procedure for detecting the positions of the guide pattern and the DSA hole pattern using the evaluation value that captures the state where the block copolymer is separated by the electron beam irradiation as described above.

  The stage 1812 is driven to move the visual field to a position on the wafer where the measurement pattern exists (S2401). After setting imaging conditions such as magnification (S2402), an image is acquired while scanning an electron beam (S2403) (S2404). The acquired image is transferred to the image processor 1823, and the image processor 1823 calculates an evaluation value for each image (S2405). As the evaluation value, for example, an image dispersion value or a sum total of pixel values of the differential image is used. The target region may be all pixel values, or may be calculated by selectively using the pixel value of the edge portion after the pattern is recognized.

  Scanning, image acquisition, and evaluation value calculation are repeated in accordance with a predetermined threshold condition for the evaluation value of each image (S2406). When the evaluation value satisfies the determination condition with respect to the threshold value, an integrated image is created (S2407). In the case of FIG. 22, an image obtained by averaging the frame images 2030, 2040, and 2050 with respect to the evaluation values 2213, 2214, and 2215 of the section 2250 of the number of frames that is equal to or greater than the threshold value 2240 is output.

  When the evaluation value obtained from the difference image in FIG. 23 is used, an image obtained by averaging the frame images 2030, 2040, and 2050 included in the section 2350 after the number of frames 2330 that is equal to or less than the threshold 2340 is output.

  That is, in the example of FIG. 24, the number of frames until the shrink amount becomes a predetermined value or less is for shrinking the specific polymer and monitoring its progress, and the signal obtained by the subsequent frames is This is an integration target for forming a measurement image. By storing such conditions in a storage medium provided in the control device or the like in association with the type of DSA pattern, it is possible to read out an appropriate device condition corresponding to the target pattern later.

  Next, a method for detecting the center of the guide pattern and the center of the DSA hole pattern will be described. First, in FIG. 22, the difference images corresponding to the evaluation values 2310, 2311, and 312 of FIG. 23 for the section 2260 of the number of frames that has become the threshold value 2240 or less or the frame section 2360 of the threshold value 2340 or more of FIG. An integrated image 25800 as shown in FIG. 25 is created. A portion having a large change in luminance value due to electron beam irradiation, such as the edge 25802 of the guide pattern portion and the DSA hole pattern portion 2503, has a high luminance as a pattern edge.

  The center position of the hole pattern is detected from the accumulated image 25800 of the difference images (S2408). For detection of the center position, the edge of the guide pattern and the edge of the DSA pattern can be detected separately by the center of gravity after blob extraction and the generalized Hough transform (S2409) (S2410). It is also possible to use edge continuity as an evaluation value by analyzing a blob. It is also possible to calculate the differential intensity from the spatial differential of the image and use the variation of the differential intensity at the edge position as the evaluation site. The method of using the continuity of the edge and the variation of the differential intensity as the evaluation value can also be applied to the line pattern. Further, according to the generalized Hough transform, the accumulated value of the Hough space can be used as the evaluation value.

  As another method for detecting the center of the hole pattern, the center position of the hole pattern can be detected by matching with a template of a pattern registered in advance. In this case, as an image to be registered in advance, an image such as an image 2050 after sufficiently irradiating an electron beam is used as a template.

  Although the evaluation value described with reference to FIG. 22 is pixel dispersion, the correlation value can also be used as the evaluation value when performing template matching.

  As another method for detecting the center of the hole pattern using the template, an edge contour line 2601 generated from the design data and an image 2602 of the guide pattern before polymer application can be used for the template as shown in FIG. When the design data is used, only the pattern edge information is used, so that the center position is detected by performing matching with the accumulated difference image 2600. Even when a guide pattern image before polymer application is used, an edge-enhanced image 2603 to which a differential filter such as a Sobel filter is applied is used as a template to perform matching with the difference image 2500 to detect the center position. After detecting the center position, a length measurement cursor is arranged (S2411), and length measurement is executed (S2412). When a plurality of patterns are included in the image as shown in FIG. 20, (S2409) to (S2412) are performed for all patterns. By registering the positional relationship between the center position and the length measurement cursor in advance, it becomes possible to accurately set the length measurement box at the edge portion of the hole to be measured.

  In the flow of FIG. 24, the imaging conditions can be stored in advance, and the scan can be executed by reproducing during the automatic operation. In this case, the number of frames 2230 having the threshold value 2240 or less in FIG. 22 or the number of frames pre-dosed from the frame section 630 having the threshold value 2340 or more in FIG. Is also possible.

  FIG. 27 shows detection when the DSA pattern edge strength is weak and difficult to detect. First, the edge of only the guide pattern (2702) is detected to obtain the center of gravity of the guide pattern (2704), and the edge of the DSA pattern is detected radially with reference to the center of gravity (FIG. 27). When the graph is drawn with the angle direction as the horizontal axis and the radial direction as the vertical axis, the result is 2705. By detecting this wave undulation, it is possible to evaluate the variation of the edge. When the edge is not stable, the variation of the edge position is large as in 2705, but when the edge becomes stable as in 2706 and 2708, the change of the edge becomes gradual (2707, 2709). By monitoring edge variations in this way, image integration can be started after the pattern has stabilized.

  FIG. 28 shows an example of a user interface for setting parameters necessary for measurement regarding the DSA pattern measurement described so far. The evaluation value threshold value is set as a threshold value for setting the cumulative start number in FIGS. 22 (2230) and 23 (2330). To execute automatic determination, check Auto (2802), and to set it manually, set the threshold value (2803). As the number of frames, the integrated number of frames of the measurement image in FIG. 22 (2250) and FIG. 23 (2350) is set. Set Auto (2805) for automatic execution, and Manual (2806) for manual execution. In Pattern Information (2807), the minimum allowable size and the maximum allowable size of the guide pattern (2808) and the DSA pattern (2809), and the gravity center shift allowable value (2810) of the guide pattern and the DSA pattern are set. If these values are outside the allowable range, the pattern size and deviation amount can be monitored in real time if a measurement error occurs.

DESCRIPTION OF SYMBOLS 101 Silicon wafer 102 Guide pattern 110 Composite polymer material 111 Polymer 112 Polymer 201 Electron source 202 Extraction electrode 203 Focusing lens 204 Blanker 205 Faraday cup 206 In-lens detector 207 Deflector 208 Objective lens 209 Oblique detector 210 Observation sample 211 Sample stage

Claims (24)

In a pattern measurement method for performing dimension measurement of a pattern formed on a sample based on detection of charged particles obtained by scanning the sample with a charged particle beam,
For a polymer compound used in the self-organized lithography technology, after a specific polymer is largely contracted with respect to another polymer among a plurality of polymers that are irradiated with charged particles to form the polymer compound, or A pattern measuring method comprising: measuring a dimension between a plurality of edges of another polymer based on a signal obtained by scanning a charged particle beam in a region including the other polymer in combination with the shrinkage. In claim 1,
Based on detection of a signal obtained by scanning the charged particle beam, the luminance of the edge portion of the specific polymer is obtained, and based on the luminance information, the irradiation of the charged particle is completed, or by the charged particle beam. A pattern measurement method characterized by starting measurement. In claim 2,
The signal is detected by a detector provided in an oblique direction with respect to the charged particle beam. In claim 1,
The charged particle for contracting the specific polymer is a charged particle emitted from the charged particle beam or a charged particle source different from the charged particle source emitting the charged particle beam. Method. In claim 4,
The another charged particle source is a planar electron source having a plane parallel to the sample surface. In a charged particle beam apparatus that performs dimension measurement of a pattern formed on a sample based on detection of charged particles obtained by scanning the sample with a charged particle beam,
Irradiation of charged particles that irradiate charged particles to a polymer compound used in self-organized lithography technology to significantly contract a specific polymer relative to other polymers among multiple polymers that form the polymer compound A signal obtained by scanning a charged particle beam in a region containing the other polymer after irradiation with charged particles or in conjunction with contraction, based on the storage medium in which the conditions are stored and the conditions stored in the storage medium A charged particle beam apparatus comprising a control device for measuring a dimension between a plurality of edges of the other polymer based on the above. In claim 6,
The control device obtains the luminance of the edge portion of the specific polymer based on detection of a signal obtained by scanning the charged particle beam, and ends the irradiation of the charged particle based on the luminance information, or A charged particle beam apparatus which starts measurement by the charged particle beam. In claim 7,
A detector is provided in an oblique direction with respect to the charged particle beam, and the control device starts execution of irradiation of the charged particle or starts measurement by the charged particle beam based on an output of the detector. Charged particle beam device characterized by the above. In claim 6,
The charged particles for contracting the specific polymer are charged particles emitted from the charged particle beam or a charged particle source different from the charged particle source emitting the charged particle beam. Wire device. In claim 9,
The charged particle beam apparatus, wherein the another charged particle source is a planar electron source having a surface parallel to the sample surface. In an apparatus condition setting method of a charged particle beam apparatus for setting a scanning condition when scanning a charged particle beam on a sample,
When forming an image based on charged particles obtained by scanning a charged particle beam on a polymer compound used in self-organized lithography technology, the charged particle beam is scanned with respect to the polymer compound, and the scanning is performed. The evaluation is performed on the image obtained based on the above, and the charged particle beam scanning and the image evaluation are repeated until the result of the evaluation satisfies a predetermined condition, and the scanning condition when the image satisfies the predetermined condition Is set as a scanning condition of the charged particle beam before scanning for image acquisition for integration. In claim 11,
An apparatus condition setting method for a charged particle beam apparatus, wherein an image obtained based on the scanning is a difference image of images acquired in different frames. In claim 11,
The image obtained based on the scan is an image obtained by scanning one frame and one frame before or one frame after the image, and the image of the one frame and one or the previous image or 1 An apparatus condition setting method for a charged particle beam apparatus, comprising: determining that the predetermined condition is satisfied when a difference from an image of a subsequent frame becomes a predetermined value or less. In claim 1,
An apparatus condition setting method for a charged particle beam apparatus, wherein an integrated image is formed based on charged particles obtained by a scan after a scan in which the evaluation result satisfies a predetermined condition. In claim 11,
The image obtained based on the scan is a difference image of images acquired in different frames, and the difference image is accumulated to form an accumulated difference image. Setting method. In claim 15,
An apparatus condition setting method for a charged particle beam apparatus, wherein the center of a hole pattern is detected based on the accumulated difference image. In claim 11,
An apparatus condition setting method for a charged particle beam apparatus, wherein a length measuring box for measuring a pattern is set based on detection of a center of a hole pattern included in the image. A scanning deflector that scans a charged particle beam emitted from a charged particle source, a detector that detects charged particles obtained by scanning the charged particle beam with respect to a sample, and an output of the detector are integrated to form an image In a charged particle beam apparatus equipped with a control device,
The control device evaluates an image obtained based on the scanning of the charged particle beam, repeats the scanning of the charged particle beam and the evaluation of the image until the evaluation result satisfies a predetermined condition, and the evaluation result is A charged particle beam apparatus characterized in that a scanning condition of the charged particle beam when a predetermined condition is satisfied is set as a scanning condition of the charged particle beam before scanning for accumulating image acquisition. In claim 8,
An image obtained based on the scanning is a difference image between images obtained in different frames. In claim 18,
The image obtained on the basis of the scan is an image obtained by scanning one frame and one frame before or after the one frame, and the control device includes the image of the one frame and the first frame. A charged particle beam apparatus characterized by determining that the predetermined condition is satisfied when a difference from an image of a previous or next frame becomes a predetermined value or less. In claim 18,
The charged particle beam apparatus according to claim 1, wherein the control device forms an integrated image based on charged particles obtained by a scan after a scan in which the evaluation result satisfies a predetermined condition. In claim 18,
An image obtained based on the scanning is a difference image of images acquired in different frames, and the control device integrates the difference images to form an accumulated difference image, apparatus. In claim 22,
The charged particle beam device, wherein the control device detects a center of a hole pattern based on the integrated difference image. In claim 18,
The charged particle beam apparatus, wherein the control device sets a length measuring box for measuring a pattern based on detection of a center of a hole pattern included in the image.

Images