TW201447225A - Method for pattern measurement, method for setting device parameters of charged particle radiation device, and charged particle radiation device - Google Patents

Abstract

The purpose of the present invention is to provide a method for pattern measurement and a charged particle radiation device, whereby patterns formed by DSA techniques can be measured and inspected with high accuracy. According to an aspect for achieving the aforementioned purpose, there is proposed hereinbelow a method for pattern measurement wherein a high-molecular weight compound employed in a self-assembled lithographic technique is irradiated with charged particles whereby, of a plurality of polymers forming the high-molecular weight compound, a specific polymer is induced to contract significantly with respect to another polymer, and on the basis of a signal obtained through charged electron beam scanning of a region containing the other polymer, the dimensions between a plurality of edges of the other polymer are measured; or a charged particle radiation device for accomplishing the measurement in question.

Description

Pattern measuring method, device condition setting method of charged particle beam device, and charged particle beam device

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

In order to generate a fine pattern, the semiconductor device in recent years is reviewing the formation of a mask pattern for etching using the Directed Self-Assembly (DSA) method. In the DSA method, the self-alignment properties of a composite polymer material in which two types of polymers are joined or mixed are utilized. Patent Document 1 describes an example in which a pattern formed by a DSA technique is observed by a scanning electron microscope, and an example in which a pattern is measured.

A charged particle beam device 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 charging a sample and observing the sample under the characteristics of the sample.

Further, in Patent Document 4, it is revealed that the electronic display is performed. In the case of the pattern measurement of the micromirror, the image is formed by integrating the plurality of pieces of image data, and the method of automatically determining the number of frames to be the object of integration is determined based on whether or not the pattern can be recognized.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-269304 (corresponding to US Patent No. 8,114,306)

[Patent Document 2] Japanese Laid-Open Patent Publication No. Hei 10-313027 (corresponding to U.S. Patent No. 6,091,249)

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2006-234789 (corresponding to US Patent No. 7,683,319)

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2010-092949 (corresponding to U.S. Patent Publication No. US2011/0194778)

The DSA technique is applied to a wafer by filling a plurality of polymers into a chemically bonded polymer compound between fine patterns formed by a general photolithography method, and the polymer is phase-separated by heat treatment. The technique of patterning is performed. Although it is a technique capable of performing fine patterning beyond the limit of exposure reduction caused by the Optical Proximity Effect, the surface of the polymer compound after heat treatment is flat, so it is mainly caused by edge effects. Secondary electron detection In the case of a submicroscope, there is a case where the contrast cannot be sufficiently obtained. Patent Document 1 discloses an observation of a pattern formed by a DSA technique using an electron microscope, but does not describe a specific method of how to enhance contrast. Further, in Patent Documents 2 and 3, it is not disclosed that a pattern formed by the DSA technique is regarded as an observation target.

Hereinafter, the first object is a pattern measurement method and a charged particle beam apparatus for measuring a pattern formed by a DSA technique using a high-contrast image or a signal with high accuracy for measurement or inspection.

In addition, if the block copolymerized polymer and the blended polymer are coated on the substrate and patterned by a hole pattern formed by optical photolithography and etching, the assembly phenomenon is induced to cause the polymer to be cylindrical. Separation. Thereafter, one of the polymers is removed by development, and the patterning of the holes is completed by an etching process.

On the other hand, in the case where the pattern separated by annealing is measured by an electron microscope or the like, there is almost no unevenness of the pattern in the state after the assembly of the bulk copolymer and the blended polymer. It is difficult to detect or measure the edge of the pattern that can be measured. In addition, it is also difficult to set an appropriate measurement range and irradiation time. In particular, in the semiconductor manufacturing process, it is necessary to determine the device conditions in advance in terms of the charged particle beam device for evaluating the result of the pattern completion. Patent Document 1 does not specifically describe how to determine such device conditions. Further, Patent Document 4 discloses a method of automatically determining the number of frames of image data to be integrated, but does not disclose how to measure a pattern having almost no unevenness. A specific solution to the setting of device conditions.

On the other hand, the inventors confirmed that a specific polymer shrinks due to irradiation of a charged particle beam. In general, among the separated polymers, the polymer which is contracted by the irradiation of the beam is a polymer which is removed by development. Therefore, if the beam conditions are appropriately set, the sample is not substantially absorbed. The damage is made possible by measuring the high accuracy of the object with the uneven pattern.

In the following, the device condition setting method for the charged particle beam device according to the second object and the charged particle beam device are described. Even if the DSA pattern has no unevenness, the scanning of the charged particle beam using the edge effect is measured. And checking for difficult patterns, high-accuracy pattern measurement and inspection based on appropriate device condition settings are still performed.

As a mode for achieving the above first object, a pattern measuring method or a charged particle beam device for realizing the measurement is proposed, based on irradiating charged particles to a polymer used in self-assembly lithography. a compound obtained by substantially scanning a specific polymer among a plurality of polymers forming the polymer compound, or a signal obtained by scanning a charged particle beam in a region containing the other polymer at the same time as shrinking The edge-to-edge sizing of the plural of the foregoing other polymers is carried out.

Furthermore, as an aspect for achieving the above second object, a device condition setting method for a charged particle beam device is proposed for a scan The scanning condition is a scanning condition of a charged particle beam when an image is formed based on charged particles obtained by scanning a charged particle beam with a polymer compound used in a self-assembly lithography technique, The compound is scanned by the charged particle beam, and the image obtained based on the scanning is evaluated, and the scanning and image evaluation of the charged particle beam is repeated until the result of the evaluation conforms to the predetermined condition, and the image is conformed to the image. The scanning conditions of the charged particle beam before scanning for the integrated image acquisition are set as the scanning conditions at the predetermined conditions.

Further, a charged particle beam device is proposed, comprising a scanning deflector for scanning a charged particle beam emitted from a charged particle source, and a detector for detecting charged particles obtained by scanning the charged particle beam of the sample, And a control device for integrating the output of the detector to form an image, wherein the control device evaluates the image obtained by scanning the charged particle beam, and repeats the scanning and image evaluation of the charged particle beam until The evaluation result is in accordance with the predetermined condition, and the scanning condition of the charged particle beam when the evaluation result is satisfied with the predetermined condition is set as the scanning condition of the charged particle beam before scanning for the integrated image acquisition.

The above-mentioned irradiation conditions are, for example, a shrinkage of a specific polymer used for image signal formation for measurement and inspection, and after performing shrinkage of a specific polymer, performing beam scanning for measurement and inspection. , or image acquisition.

According to the first configuration described above, even if a polymer compound having a plurality of flat surfaces is used as a polymer compound, high-contrast measurement using a high-contrast signal is possible.

Further, according to the second configuration described above, even if there is no unevenness in the DSA pattern, the measurement and inspection of the scanning of the charged particle beam using the edge effect are difficult patterns, and the high-accuracy pattern set based on appropriate device conditions is used. Measurement and inspection are still possible.

101‧‧‧矽 wafer

102‧‧‧ Guide pattern

110‧‧‧Composite polymer materials

111‧‧‧ polymer

112‧‧‧ polymer

201‧‧‧Electronic source

202‧‧‧Extraction electrode

203‧‧‧focus lens

204‧‧‧Blocker

205‧‧Faraday Cup

206‧‧‧In-lens detector

207‧‧‧ deflector

208‧‧‧ Sight objective

209‧‧‧ oblique detector

210‧‧‧ observation samples

211‧‧‧Sample table

FIG. 1 is a view showing an example of a pattern created by the DSA method.

FIG. 2 is a diagram showing an outline of a scanning electron microscope.

FIG. 3 is a diagram showing the relationship between the cross section of the DSA pattern and the SEM image.

FIG. 4 is a diagram showing the relationship between the cross section of the DSA pattern and the SEM image formed based on the output of the oblique detector.

[Fig. 5] A diagram showing four oblique detectors.

Fig. 6 is a view showing an oblique detector formed by a detecting element divided into four elements.

FIG. 7 is a view showing an example of a scanning electron microscope including a processing electron source.

FIG. 8 is a view showing an example of a planar electron source.

FIG. 9 is a view showing an arrangement example of a planar electron source.

FIG. 10 is a view showing an arrangement example of a planar electron source.

Fig. 11 is a view showing an arrangement example of a planar electron source.

FIG. 12 is a view showing an example of a scanning electron microscope including a planar electron source.

Fig. 13 is a view showing the orbit of electrons when the processing beam is irradiated.

Fig. 14 is a flow chart showing the procedure from the processing of the DSA pattern to the measurement of the DSA pattern.

FIG. 15 is a view showing an example of a GUI screen for setting the preliminary irradiation conditions.

Fig. 16 is a view showing an example of a table in which preliminary irradiation conditions corresponding to the types of patterns provided for the purpose of preliminary irradiation are memorized.

Fig. 17 is a view showing an example of a pattern size measuring system including a scanning electron microscope.

Fig. 18 is a schematic view showing a scanning electron microscope.

FIG. 19 is a view showing an example of a DSA hole pattern image with a guide pattern. FIG.

FIG. 20 is a block diagram showing a state in which a guide pattern and a DSA hole pattern are imaged in the case where an electron beam is irradiated.

[Fig. 21] A diagram showing a difference image of the frame images before and after.

[Fig. 22] A graph for plotting the evaluation values obtained from the frame image group of Fig. 20.

[Fig. 23] A graph for plotting the evaluation values obtained from the differential image group of Fig. 21.

FIG. 24 is a flow chart showing a measurement procedure using integrated images.

FIG. 25 is a diagram showing an example of an image integrated for a difference image.

[Fig. 26] A diagram illustrating a technique for detecting the center of a hole pattern using a stencil.

Fig. 27 is a view for explaining a detection method of a guide pattern.

FIG. 28 is a diagram showing an example of a GUI screen for inputting measurement parameters.

Figure 1 is a schematic representation of a micropattern by the DSA method. Fig. 1(a) shows a germanium wafer 101 which is a substrate on which a pattern is formed. In FIG. 1(b), a lithographic technique is employed over 101 to create a wide pitch pattern 102 that is wider than the desired fine pattern repeat pitch. Thereafter, the composite polymer material 110 is coated in FIG. 1(c). With proper heat treatment (annealing), the 110 series uses the pattern 102 as a guide to self-align in a particular direction. The 110 system is composed of two types of polymers 111 and 112 overlapping each other. In Fig. 1(d), by selectively removing one of the polymers (e.g., 112), a narrow pitch pattern 103 having a pitch narrower than the guide pattern 102 can be formed.

It is important to judge whether or not the phase separation is properly performed after the heat treatment and before the etching, and it is important to know whether or not an appropriate polymer material is selected in the early stage, and whether the annealing conditions are appropriate, etc., but as shown in Fig. 1(c) For example, although a polymer is contained in a polymer material, the surface is still flat, so that a high contrast image cannot be obtained by a scanning electron microscope. The inventors have based on the above-mentioned situation, and have newly discovered that one of the components of the SEM for performing inspection/measurement of the DSA pattern is For the surface treatment used for contrast emphasis. In the measurement and inspection of the pattern, it is important to detect the pattern defect as early as possible to reduce the time/economic cost, and it is preferably carried out at the stage of Fig. 1(c) without going through the steps of Fig. 1(d). In this state, there is no difference in height between the polymer 111 and the polymer 112, and normal SEM observation is difficult. Further, there is no significant difference in the mass density of the polymer 111 and the polymer 112, and the contrast using the difference in mass density cannot be obtained. Further, the electrical properties of the polymer 111 and the polymer 112 are both in the case of an insulator, and the potential contrast using the charged potential difference cannot be obtained.

In the embodiments described below, a method and apparatus are provided for observing a narrow-pitch pattern generated by the DSA method while irradiating the charged particle beam to the observed region in advance. The charged particle beam is irradiated to the observed region in advance so that one of the pair of polymers (111 and 112 in Fig. 1) can be reduced in volume. By this means, it becomes possible to form a step in accordance with the shape of the pattern on the surface of the polymer, and high-accuracy measurement/inspection can be performed. Further, the charged particle beam system irradiated in advance to the observed region is treated as the same as the charged particle beam used for the subsequent observation.

[Example 1]

An example of a scanning electron microscope in which high-contrast signal measurement based on a DSA pattern of a high contrast signal is made possible will be described using a drawing. Figure 2 is a schematic diagram showing 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. lead The output electrode 202 is set to a positive potential higher than the electron source 201 by a positive voltage source 232 superposed on the control power source 231, and the electron beam 220 is taken out. The electron beam 220 is irradiated onto the observation sample 210 via the focus lens 203 and the objective lens 208. The diameter of the electron beam 220 on the sample 210 is suitably controlled by the lens control circuits 233 and 238. Further, the amount of current of the electron beam 220 is detected by the Faraday cup 205, and is measured by the current measuring means 235. The electron beam 220 scans the observation field through the deflector 207 that operates by biasing the control circuit 237. When the electron beam 220 is retracted from the sample 210, the blocker power supply 234 is used to operate the blocker 204. The signal electrons generated from the sample 210 are detected by an in-lens detector 206 disposed closer to the electron source 201 than the objective lens 208 or an oblique detector 209 disposed in a specific direction. The in-lens detector is a high-efficiency detector for detecting low-speed signal electrons emitted from the sample in all directions, thereby providing an edge-contrast image suitable for emphasizing the edge portion of the surface step. On the other hand, the oblique detector 209 is adapted to detect high-energy signal electrons that are emitted in a particular direction of the sample.

When observing the pattern created by the DSA method, the observation sample 210 is placed on the sample stage 211 and transported under the objective lens 208. The observed portion is scanned in advance by electron beam 220 to reduce the volume of one of the polymers to form a surface step. This procedure is referred to as processing illumination. On the basis of this, the electron beam 220 is again scanned for the observation portion, and the signal of the in-the-lens detector 206 is imaged by the signal processing device 236 to obtain a microscope image. In this case, as long as the processing illumination is sufficient, then The edge portion of the pattern by the DSA method forms a step, and the resulting microscope image shows a clear edge contrast at the boundary of the two types of polymer. By using this edge line, it is possible to perform a high-accuracy measurement of the pattern size on the observed sample or a defect inspection of the pattern shape on the observed sample.

According to the following configuration, it is possible to quickly perform high-accuracy evaluation of the DSA pattern based on a plurality of polymers which will form the polymer compound by irradiating the charged particles to the polymer compound used in the self-assembly lithography technique. The specific polymer in the medium is substantially shrunk relative to the other polymer, and then the signal obtained by scanning the charged particle beam in the region containing the other polymer is subjected to the edge-to-edge size measurement of the plural of the other polymers.

Fig. 17 is a view showing an example of a pattern measuring system including SEM 1701, which is mainly composed of a control device 1702 for controlling SEM 1701 and SEM 1701, and an optical condition setting device for setting desired device conditions for control device 1702. 1703 and a setting device 1704 for setting the measurement conditions by the SEM. The display device provided in the setting device 1704 can display a GUI (Graphical User Interface) screen as illustrated in FIG. The GUI screen illustrated in Fig. 15 is provided with an input window 1501 for inputting a type of pattern, and an input for inputting a beam irradiation condition before beam scanning for measurement. Window 1502. In the case of the present embodiment, the edge of the other polymer can be emphasized by reducing the volume of one of the above polymers from the potential contrast (Contact Contrast) and the contact hole (C/H) observation. Edge Enhancement's 3 Select Pre-Scan modes.

The preliminary scanning in the potential contrast mode performs beam scanning (first scanning mode) in accordance with the beam conditions for charging the elements included in the field of view. The preliminary scanning in the contact hole observation mode performs beam scanning (second scanning mode) for positively charging the resist layer on the sample surface. Then, in the preliminary scanning of the edge emphasis mode, scanning is performed in order to reduce one polymer (third scanning mode).

Among the three scanning modes, only the third scanning mode is a scanning mode in which the sample is not charged. In the present embodiment, a GUI screen for providing a window for setting the preliminary irradiation conditions for measuring such a DSA pattern is provided.

As described above, there are various types of preparatory scanning systems, and the beam conditions are different. Therefore, the following is made as shown in FIG. 16 to make the selection of the preliminary scanning conditions easier: in the scanning mode, each of the patterns is prepared. The database of the beam conditions of the type is read based on the type of pattern and the scanning mode. In addition, the preparation of such a database is made to update the conditions for the measurement of an unknown sample, that is, it becomes easy to set the past setting conditions. It is also possible to create a field of view (FOV (Field Of View)), an exposure time (Exposure Time), a beam current (Beam Current), and a beam reaching the sample when performing preliminary scanning on the GUI screen illustrated in FIG. 15 . The selection of the Landing Energy, the number of frames, the type of pattern, and the selection of the preliminary scanning mode are updated as shown in Figure 16. Library.

The database is registered in the memory 1705 built in the optical condition setting device 1703, and the optical condition of the SEM 1701 is set by setting the setting device 1704. The arithmetic processing unit 1706 provided in the optical condition setting device 1703 includes an optical condition setting unit 1707 for setting beam conditions for measurement, a database registered in the memory 1705, or a setting device 1704. The preliminary irradiation condition setting unit 1708 that sets the pre-scanning conditions, the brightness condition extraction unit 1709 that sets the conditions for stopping the preliminary irradiation, which will be described later, and the beam scanning for measurement, are formed. The distribution waveform is a pattern measuring unit 1710 that measures the size of the pattern.

According to the above configuration, it is possible to perform measurement using the edge which is revealed by the processing with high accuracy.

Figure 3 is a graph showing the relationship between the cross section of the DSA pattern and the SEM image. In Fig. 3a, the DSA pattern and the SEM image before the irradiation of the processing are performed. There is no surface step difference between the two types of polymers 301 and 302, and the contrast of the SEM image is not attached. Fig. 3b shows the case where the volume of the polymer 302 is reduced by irradiation with a beam. A large number of signal electrons are generated from the sidewall of the unreduced polymer 301, and a clear strong signal region (white band) 303 is formed at the boundary of the polymer 301 and the polymer 302. Thereby, it becomes possible to perform measurement/inspection of the DSA pattern. Fig. 3c shows the use of the method of the present invention, but the volume is reduced to an insufficient condition. In this case, the amount of signal electrons from the side wall of the polymer 301 is insufficient, and the white strip 304 is also weak. More specifically, it is also known from the enlarged view of the pattern of FIG. 3: compared to The edge 305 of the first end that is in contact with the portion of the unfilled polymer 302 is weaker than the white strip 303 that is subjected to a sufficiently processed pattern edge.

In the case of a particularly unknown sample, in order to ensure sufficient measurement accuracy, it is preferable to use a method for determining whether or not the irradiation for processing is sufficient.

Fig. 14 is a flow chart showing the procedure from processing to measurement. The following processing is based on the setting conditions set by the optical condition setting device 1703, and the control device 1702 controls the SEM 1701 to execute. First, beam scanning is performed for processing and checking for proper processing (step 1401), and a distribution for monitoring the processing state is formed (step 1402). At this time, the brightness of the edge portion is monitored, and the difference in luminance between the peak top and the peak bottom is determined (step 1403). At this time, 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, the beam scanning for dimension measurement is performed (step 1404). A distribution is formed based on the charged particles obtained as a result of the beam scanning at this step 1404 (step 1405), and sizing of the pattern using the formed distribution is performed (step 1406).

Unlike the case where a particular component is selectively charged, as the preliminary illumination continues, the luminance signals of the edges and the other portions become relatively different, so the relative transition between the edge portion and the other portions is different. As an evaluation, it becomes possible to find an appropriate processing end point. In addition, it is also possible to make a comparison that the brightness information is not the height of the peak, but for example, the change in the peak width. In addition, it is formed to be formed for dimensional measurement. The distribution signal for processing monitoring is not included in the distribution, making it possible to perform high-accuracy dimensional measurements.

Further, as described later, when charged particle detection for processing monitoring and detection of charged particles for pattern size measurement are performed at the same time, it is also possible to selectively use the processing when the distribution for measurement is formed. The subsequent signal can also be used to receive the output signal of the detector after processing.

Fig. 4 is a view showing an image formed based on charged particles detected by the oblique detector 209 which is obliquely arranged with respect to the beam optical axis, for the same observation object as Fig. 3. The image of the oblique detector 209 is imaged by the inclined surface of the sample whose normal direction is toward the detector, so that the normal direction of the sample facing the detector is imaged as dark. In other words, the edge having the cross section facing the detector side is brightened, and the edge having the cross section facing away from the detector side is darkened.

Fig. 4a is an SEM image of the DSA pattern before the irradiation of the processing beam. There is no surface step difference between the two types of polymers 401 and 402, so that even the SEM image based on the detection by the oblique detector does not have contrast. 4b and 4c are SEM images in the case where the processing by the beam irradiation is performed to reduce the volume of the polymer 402.

The sidewall portion of the sidewall of the polymer 401 whose volume is not reduced, facing the oblique detector, and a portion of the polymer 402 are imaged to be bright, and the sidewalls of the back side and a portion of the polymer 402 are imaged to be dark. . In addition, in FIG. 4, the brightness 404 of the upper portion of the polymer and the brightness 404 of the cross-sectional portion facing the detector side when the processing is sufficiently performed are sufficiently processed. The brightness 405 of the cross-sectional portion facing the detector side in the opposite direction, the brightness 406 of the cross-sectional portion facing the detector side when the processing is not sufficiently performed, and the face and detector side when the processing is not sufficiently performed are The brightness 407 of the cross-sectional portion in the opposite direction is expressed in a different display form.

The greater the difference in brightness between the bright portion and the dark portion, the deeper the surface step difference, and the smaller the difference in luminance, the shallower the surface step difference, so that the image of the oblique detector can be used, and whether the irradiation for processing is sufficient is judged. . More specifically, it is conceivable that the borrowing control device forms a histogram having the luminance as the horizontal axis and the detection number as the vertical axis based on the signal output of the oblique detector disposed in the specific direction, and has a histogram having a predetermined luminance. When the luminance difference between the two peaks in the graph is equal to or greater than a predetermined value, it is determined that the processing has ended. Further, since the cross section facing the detector side is brightened as the processing continues, it is also possible to determine that the processing is completed when the brightness of the edge portion on the detector side is equal to or higher than a predetermined value. However, since the brightness of the edge portion varies depending on the shape of the cross section and the material of the polymer, the method of determining the relative ratio of the brightness of the dark portion to the bright portion can perform the processing end detection with higher accuracy.

By performing the end-of-process detection with high accuracy, it is possible to achieve high-accuracy measurement without the long-term measurement and the excessive beam irradiation. Further, by separately providing a detector for measurement and a detector for processing monitoring, it is possible to immediately shift to measurement after processing.

In the above-described processing amount determination, it is assumed that the direction of the side wall of the pattern does not necessarily coincide with the orientation of the oblique detector. As the oblique detector, a plurality of oblique detectors corresponding to different orientations may also be provided. Figure 5, is in 4 squares An example of a stand-alone diagonal detector. The signal electrons 501a, 501b, 501c, 501d generated by the electron beam 220 from the sample 210 are detected by the oblique detectors 502a, 502b, 502c, 502d according to their emission directions, respectively. Alternatively, a detection element (semiconductor detector, multi-channel plate, avalanche type photodiode, CCD) in which a detector having a single detection surface is divided into a plurality of detectors may be used. Fig. 6 is an example of an oblique detector in which a detecting element divided into four elements is arranged. The signal electrons are detected by any of the elements 601a, 601b, 601c, 601d depending on their exit direction.

Further, in order to perform processing irradiation more efficiently, the lens control circuit 233 or 238 may be changed to have a diameter on a sample different from the electron beam at the time of observation, and the control power source 231 may be used to control the electrons at the time of observation. The beam is irradiated with different energies. Similarly, the amount of current, the scanning speed, the scanning area, and the like can be set differently for observation in order to perform processing efficiently.

[Embodiment 2]

In the above description, the processing before the measurement is performed using the beam for measurement or the beam condition of the measurement beam, but the following description will be given: A beam source different from the beam source of the measurement beam is provided in the charged particle beam device, and processing is performed using the different beam source.

In the present embodiment, an example is described in which a processing beam source that should be irradiated with a processing beam from a direction perpendicular to the sample surface is formed in parallel along the sample surface. To set the beam source for processing to the charged particle beam In the case of the inside, it is necessary to arrange it at a position other than the beam trajectory emitted from the beam source for measurement. For example, when the beam source for processing is disposed at a position inclined with respect to the beam trajectory of the beam for measurement, since the beam is irradiated from a direction inclined with respect to the surface of the sample, the polymer is uneven. Except, there is a possibility of generating an error in inspection/measurement.

Further, in order to illuminate the beam perpendicularly to the observation portion, it is also conceivable that the beam introduced from the oblique direction is bent by the deflector to be guided to the observation portion, but the deflector for bending generally causes the observation electron. When the beam is subjected to aberration, the surface treatment and observation are simultaneously performed, causing deterioration in resolution. The deterioration of the resolution has a possibility that the measurement accuracy of the narrow-pitch pattern measurement is lowered.

Further, when it is intended to provide another electron source such as a floodlight type electron gun, there is a possibility that the vacuum chamber is enlarged.

In the present embodiment, a configuration in which the first charged particle beam used for observation and the second charged particle beam previously irradiated to the observed region are different will be described. Further, an example in which the observation by the first charged particle beam and the irradiation of the second charged particle beam are simultaneously performed will be described together. Furthermore, it is also described that the emission source (first charged particle beam source) of the first charged particle beam is an emission source of the particle beam optical axis and the second charged particle beam (second charged particle beam source) ) is the same example.

By making the optical axes the same, it is possible to process the charged particles with no deviation to the narrow pitch pattern, and it is possible to perform processing and observation without moving the sample, so that the vacuum chamber can be miniaturized. In addition, the emission from the processing beam The beam emitted from the source is perpendicular to the sample surface, and the beam for processing is coaxial with the beam system for measurement. Therefore, it is possible to perform processing and measurement without loss of resolution by deflection of the deflector. .

According to the present embodiment, it is possible to provide a charged particle beam device capable of high molecular recognition even for the arrangement of molecular polymers formed by the DSA method without surface steps and having little difference in mass density. The boundary is identified. Further, under the maintenance of the resolution, the high-efficiency homogenization in a short time makes the volume of the polymer decrease, and the inspection/measurement of the high accuracy of the fine pattern becomes possible.

Specific examples of the embodiment will be described below using the drawings. Figure 7 is a schematic diagram showing a scanning electron microscope (SEM). The electron source 701 is held at a negative potential with respect to the sample by the control power source 731. The extraction electrode 702 is set to have a positive potential than the electron source 701 by a positive voltage source 732 that is superposed on the control power source 731, and the electron beam 720 is taken out. The electron beam 720 is irradiated onto the observation sample 710 via the focus lens 703 and the objective lens 708. The diameter of the electron beam 720 on the sample 710 is suitably 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 is measured by the current measuring means 735. The electron beam 720 scans the observation field through the deflector 707 that operates by biasing the control circuit 737. When the electron beam 720 is retracted from the sample 710, the blocker 704 is operated using the blocker power supply 734. The signal electrons generated from the sample 710 are detected by the detector 706, and are imaged by the signal processing device 736 to obtain a microscope image.

Between the sample 710 and the objective 708, a planar electron source 709 is disposed, the action of which is controlled by the control power source 739. The planar electron source is mainly used as an illuminator for processing DSA patterns. The planar electron source 709 has an optical axis shared with the electron source 701 for observation. FIG. 8 is a view showing a specific form of the planar atomic source 709 in a coaxial arrangement.

The planar electron source 709 is formed into a circular disk shape having a disk shape with a hole in the center. In particular, in the case where the central hole and the electron beam 720 have a common axis, it is considered that the two electron sources 709 and 701 are coaxially arranged. The vicinity of the observation site of the sample 710 can be equally processed, so that the outer diameter portion of the planar electron source 709 is rounded and does not impair the features of the present invention. As shown in FIG. 8, the planar electron source 709 is formed by the emission surface 802 and the extraction surface 803. The control power supply 739 is formed by a high voltage power supply 805 that regulates the acceleration voltage of the planar electron source 709, and a high voltage power supply 806 that is a potential difference between the extraction surface 803 and the emission surface 802. It is stipulated that the electron beam is taken out.

In the configuration of Fig. 7, most of the signal electrons generated from the sample are shielded by the planar electron source 709, and the number of electrons reaching the detector 706 is slightly small. In this case, as shown in FIG. 9, the oblique detector 901 may be provided on the outer side of the planar electron source 709. In particular, as described in the first embodiment, it is important to detect the edge portion of the observation pattern by the oblique detector, so that the oblique detector 901 can be regarded as the main detector.

Alternatively, as shown in FIG. 10, the planar electron source 709 may be disposed 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 achieved. In this case, face The upper electron source 709 narrows the angle at which the sample 710 is estimated, and there is a possibility that the amount of irradiated electrons decreases. The illumination current from the planar electron source 709 is preferably directed to the sample 710 by borrowing the objective lens 708 or an additional lens.

Alternatively, as shown in FIG. 11, it is also possible to configure the planar electron source 709 to have the same height as the focus point 1102 of the signal electron 1101. Focusing point 1102 is very small and can pass through a hole in the center of planar electron source 709. By this means, the planar electron source 709 can be placed closer to the sample 708 side than the detector 709, and the irradiation current can be efficiently guided to the sample 710.

[Example 3]

Furthermore, other embodiments are described using the drawings. Figure 12 is a schematic diagram showing 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 source 1231. The potential of the aforementioned electron source 1201 with respect to the aforementioned sample 1211 was made VP (<0). The extraction electrode 1202 is set to be a positive potential VP1 further than the electron source 1201 by a positive voltage source 1232 superposed on the control power source 1231, and the electron beam 1220 is taken out. The electron beam 1220 is irradiated onto the aforementioned sample 1211 via the focusing lens 1203 and the objective lens 1208. The diameter of the electron beam 1220 on the sample 1211 is suitably controlled by the lens control circuits 1233 and 1238. Further, the amount of current of the electron beam 1220 is detected by the Faraday cup 1205, and is measured by the current measuring means 1235. The electron beam 1220 is biased by the biasing control circuit 1237. The viewer 1207 scans for the field of view. When the electron beam 1220 is retracted from the sample 1211, the blocker power supply 1234 is used to operate the blocker 1204.

The signal electrons generated from the sample 1211 are detected by an in-the-lens detector 1206 disposed closer to the electron source 1201 than the objective lens 1208, or an oblique detector 1214 disposed in a specific direction, to the signal processing device 1236 or 1244 was used for visualization to obtain a microscope image. An energy filter 1213 is disposed between the oblique detector 1214 and the sample 1211 described above. 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 aforementioned sample 1211 was made VF. Further, the planar electron source 1209 has a mesh-shaped lead-out surface 1210. The lead-out surface 1210 is controlled by the high-voltage power source 1240 superimposed on the control power source 1239 with respect to the potential VF1 of the lead-out surface 1210 of the planar electron source 1209. The electron beam irradiated from the planar electron source 1209 to the sample 1211 is mainly used as a processing irradiation for the DSA pattern. When the irradiation from the planar electron source 1209 to the sample 1211 is not performed, a stopper may be provided between the planar electron source 1209 and the sample 1211 in principle. However, since the irradiation area is large and there is a problem in that the electron beam is deflected by the stopper, a method of making the potential difference VF very small or a positive value is used to reduce the number of electrons reaching the sample, or to use the electron source. VF1 is very small or negatively generated to cause electrons emitted from the planar electron source 1209 The method of reducing the number.

Referring to Fig. 13, there will be described a method in which electron beam irradiation for processing by surface electron source 1209 and acquisition of SEM image are simultaneously performed. Figure 13 is a detailed view of the planar electron source and oblique detector shown in Figure 12. In addition, it is not necessary to use an oblique detector, and it can be implemented by a similar configuration of the in-lens detector 1206.

When the processing irradiation and the SEM image are simultaneously performed, not only the electron beam 1220 but also the electron beam 1303 irradiated for processing generates the signal electrons 1304 from the sample 1211. The spatial resolution of the SEM image is dependent on the diameter of the sample 1211 of the electron beam 1220. Since the spatial range of the electron beam 1303 for processing is sufficiently larger than the diameter of the electron beam 1220, the signal electrons generated by the processing electron beam 1303 cannot give high spatial resolution, and the signal generated by the two electron beams is detected. The resolution of the SEM image deteriorates when electrons are used. In order to avoid this problem, the potential VP of the electron source 1201 is set to be lower than the potential VF of the planar electron source 1209 (made VP < VF).

Thereby, the kinetic energy of the electron beam 1220 for observation when it is incident on the sample 1211 is greater than the kinetic energy of the electron beam 1303 for processing when it is incident on the sample 1211. Therefore, the maximum energy EP of the signal electrons generated by the observation electron beam 1220 must be greater than the maximum energy EF (EP>EF) of the signal electrons generated by the electron beam 1303 for processing.

Next, the threshold voltage Eth of the energy filter 1213 is first selected so that EP>Eth>EF, and the filtered signal electron 1305 detected by the oblique detector 1214 is used only for observation. The sub-beam 1220 is composed of electrons generated. According to the above method, processing and observation can be simultaneously performed with high efficiency without deteriorating the image quality.

[Example 4]

The embodiments described below mainly relate to a charged particle beam apparatus which performs scanning and scanning of a sample with a charged particle beam to perform inspection and measurement of a sample. The sample pattern observed was a contact hole and a via pattern formed by the block copolymer copolymer and the blended polymer formed by the induction assembly.

In a general semiconductor device, a circuit pattern is formed by a plurality of layers. Lead holes and contact holes are formed in order to connect the circuit patterns of the layers. The via holes and the contact holes are used for connection between a lower layer transistor and circuit wiring, other components and circuit wiring, and wiring. Conventional methods for fabricating via patterns and contact holes have been conventionally performed by photolithography and etching depending on the position and size of the design data. In the latest immersion lithography and dry etching, it is possible to form a via pattern before and after about 30 nm, but it has become difficult to use conventional optical lithography for the analysis of the via pattern after the 22 nm node. The fundamental problem of the miniaturization of such semiconductor device patterns has been the combination of two-exposure and super-resolution techniques, EUV exposure and electron beam exposure, but at this stage, there is no comprehensive compliance in terms of manufacturing cost and technical level. Production requirements.

A patterning technique using induced assembly of a bulk copolymer and a blended polymer can be used to form a fine pattern without using an expensive exposure apparatus. In particular, in the formation of a DSA hole using a hole pattern to be guided, it has become possible to generate fineness while controlling the position of the pattern. Hole pattern.

If the block copolymerized polymer and the blended polymer are coated and annealed on the substrate by a pattern of holes formed by optical photolithography and etching, the assembly phenomenon is induced to cause the polymer to be cylindrically separated. Thereafter, one of the polymers is removed by development, and the patterning of the holes is completed by an etching process.

In the state after the induction of assembly, instead of development, the charged particle beam is irradiated to pattern the shrinkage phenomenon by a polymer component (for example, PMMA or the like) which is liable to react with the charged particle beam. A partially separated DSA pattern image can also be obtained by an inspection apparatus that irradiates a charged particle beam before development in this manner.

The image obtained in this manner can be evaluated by measuring the diameter of the DSA hole and the positional deviation of the DSA hole formed as a guide pattern.

If there is no problem with the evaluation result, the development process is carried out, and a hole pattern is formed through an etching process. If the evaluation result is not good, the conditions of the manufacturing apparatus of the program before reworking or changing are performed and the pattern is re-formed. In this way, the information obtained by the measurement and evaluation of the fine hole pattern of the charged particle beam is fed back to the manufacturing apparatus, so that the yield and quality of the semiconductor program can be improved.

In the charged particle beam apparatus used for inspection of a semiconductor program, such as a length measuring SEM, it is necessary to determine the number of scanning frames or the like in advance in order to perform automatic operation. In the pattern of the DSA program, the electron beam is irradiated to become an edge of the observable pattern, but the interaction between the charged particle beam and the polymer component is generally unstable, so that it is difficult to determine the number of integrated frames. For this reason, it has become difficult to detect the position of the pattern by using the template matching or the like of the registered template.

In the present embodiment, the characteristics of the charged particle beam device and the low signal-to-noise ratio are low, and it is difficult to separate the signal from the noise by using a small addition signal to detect the edge of the pattern.

As far as the DSA procedure is concerned, the image is not stabilized unless the charged particle beam is irradiated for a fixed period of time. Therefore, it is difficult to determine the electron beam irradiation time before the most suitable image acquisition.

In the case of pattern detection using a registered template, since the pattern observed in the DSA program is liable to change due to irradiation of the charged particle beam, there is a possibility of causing positional deviation.

It is required to monitor the positional deviation of the DSA pattern formed as the guide pattern in the DSA program.

In the following examples, it is explained that the charged particle beam is scanned in a state after the induced assembly of the bulk copolymer and the blended polymer, based on the charged particles from the self-scanning portion. Scanning electron microscope for identifying and measuring pattern positions based on information and evaluation criteria. In addition, the following method is also described: the electron beam is irradiated to capture the change of the signal and the image from the pattern of the DSA program, and the condition is determined based on the evaluation value for the number of integrated frames and the like.

It also describes the following example: the evaluation value is combined with the signal intensity and brightness variation of the image, edge sharpness and edge continuity to detect the measurement range and the pattern position.

It also explains the following example: in order to divide the pattern edge signal and noise The image from the initial stage of the DSA pattern charged particle beam irradiation is measured in advance for the noise level such as the dispersion value, and is used as an evaluation standard.

It also illustrates the following example: The timing of the brightness of the edge of the guide pattern and the DSA pattern is determined after capturing changes in the signal and image from the pattern of the DSA program.

It also explains the following example: In the case of pattern detection by registering the template, the unstable pattern signal of the DSA program is not used, and the virtual image generated from the guided pattern image and the design data after the etching is used as Login with the template for pattern detection.

According to the above configuration, it is possible to recognize and measure the pattern position in a state in which the block copolymer polymer and the blended polymer are induced and assembled. In this mode, the measurement range is automatically set.

When the pattern of the DSA program is imaged during the automatic operation of the charged particle beam device, the appropriate number of frames and the pre-allocation time can be determined. In addition, stable pattern position detection and measurement can be performed by using the evaluation value of the complex number. Furthermore, the image from the initial stage of the DSA pattern charged particle beam irradiation is previously measured for the noise level to separate the pattern edge signal from the noise, so that the erroneous detection of the pattern can be reduced.

When the template is registered for automatic operation, the virtual image generated from the etched guide pattern image and the design data is registered as a template, and the pattern detection is used to enable stable pattern detection.

Fig. 18 is a block diagram showing an outline of a configuration of a scanning electron microscope. The overall control unit 1825 is based on input from the user interface 1828 by the operator. The acceleration voltage of the electrons, the information of the wafer 111, the observation position information, and the like are transmitted through the electro-optical system control device 1826 and the table control device 1827 to control the entire device. The wafer 1811 is passed through a sample transfer device (not shown) and is fixed to the stage 1812 of the rear sample chamber 1813 through the sample exchange chamber.

The electro-optical system control device 1826 is for the high voltage control device 1815, the first focus lens control portion 1816, the second focus lens control portion 1817, the secondary electronic signal amplifier 1818, and the calibration control portion 1819 in accordance with commands from the overall control portion 1825. The deflection signal control unit 1822 and the objective lens control unit 1821 perform control.

The primary electron beam 1803 drawn from the electron source 1801 by the extraction electrode 1802 is bundled by the first focus lens 1804, the second focus lens 1806, and the objective lens 1810, and is irradiated onto the sample 1811. The in-transit electron beam passes through the aperture 1805, and the track is adjusted by the calibration coil 1808. Further, the deflection coil 1808 receives the signal from the deflection signal control unit 1822 through the deflection signal amplifier 1820 for two-dimensional scanning on the sample. Due to the irradiation of the primary electron beam 1803 of the wafer 1811, the secondary electrons 1814 discharged from the sample 1811 are captured by the secondary electron detector 1807 and transmitted through the secondary electronic signal amplifier 1818 as a secondary electronic image display. The brightness signal of device 1824 is used. The deflection signal of the secondary electronic image display device 1824 and the deflection signal of the deflection coil are synchronized, so that the pattern shape on the wafer 1811 is faithfully reproduced on the secondary electronic image display device 1824.

In addition, in order to create an image for measurement of the size of the pattern, The signal output from the secondary electronic signal amplifier 1818 is AD-converted in the image processing processor 1823 to produce digital image data. In addition, secondary electron distribution is made from digital image data. In the present embodiment, the arithmetic unit such as the image processing processor 1823 is used to select the image data to be integrated as will be described later. Further, there is a case where the arithmetic unit and the control unit are included and the control unit is simply referred to.

The range of measurement from the secondary electron distribution is manually selected, or automatically selected based on a certain algorithm, and the number of pixels in the selected range is calculated. The actual size of the observation area scanned from the electron beam 1803 and the number of pixels corresponding to the observation area are measured for the actual size on the sample.

In the above description, an example of a charged particle beam device is used as an example of a scanning electron microscope using an electron beam. However, the present invention is not limited thereto, and may be, for example, an ion beam irradiation device using an ion beam.

A schematic diagram 1900 of a representative pattern image for use in a DSA aperture pattern with a guide pattern is shown in FIG. The schematic 1900 of the DSA hole pattern image has four DSA hole patterns (1901, 1902, 1903, 1904) with guiding patterns. The pattern of holes (1911, 1912, 1913, 1914) as guide holes is generally formed by a photolithography process and an etching process of the optical exposure device. Typically, the DSA hole pattern (1921, 1922, 1923, 1924) is after coating the bulk copolymer and the blended polymer, and the polymer is separated in an annealing procedure for induction assembly. Thereafter, one polymer is removed by development to perform patterning by an etching process. However, instead of inducing development after assembly, irradiation with an electron beam allows a polymer which is easily reacted with an electron beam (for example, PMMA or the like) to contract, and the edge of the DSA hole can also be seen. A partial (checkpoint only) separated DSA pattern image can also be obtained by an inspection apparatus that irradiates with an electron beam before development in this manner. In addition, although a block type copolymer polymer is described below, the same is also true about the polymer to be blended.

Figure 20 is a schematic diagram showing the image of each frame for the DSA holes to be imaged in the case where the DSA hole pattern coated with the bulk copolymer is irradiated with an electron beam. The image 2000 guide pattern and the DSA hole pattern appearing from the electron beam irradiation are slowly displayed (2000, 2010, 2020, 2030, 2040, 2050). The image 2000 after the irradiation with the electron beam is almost impossible to observe the DSA hole for the guide pattern. The image 2050 which has been sufficiently irradiated with an electron beam becomes clear to the bottom 2053 of the DSA hole pattern after the edge 2052 of the guide pattern hole is separated from the bulk copolymer. In this case, although the image of the frame image of each hole pattern is shown, the case of the line pattern may be a signal distribution for each line scan. In addition, it is also possible to use a plurality of images for the frame to calculate the average.

Fig. 21 is an image obtained by calculating the difference between the front and rear images in the image of each frame illustrated in Fig. 20. The difference image 2110 is an image obtained by subtracting 2100 from the frame image 2110. Similarly, the difference image 2120 is subtracted from the frame image 2120 by 2110, and the difference image 2130 is obtained by subtracting 2120 from the frame image 2130. The difference image 2150 is obtained by subtracting the frame image 2040 from the frame image 2050, but its luminance value becomes close to zero. value. This means that the frame image 2050 and the frame image 2040 have almost no change. This variation is mastered in the present invention for detecting the number of frames and the position of the guide pattern and the position of the DSA pattern. The comparison between the plurality of images extracted during beam scanning for the same object in this manner allows for the selection of appropriate device conditions. The images of the plural numbers obtained by different frame numbers are basically the same object, and it can be said that the self-correlation evaluation is performed. For example, the reference image is prepared in advance, and it is possible to perform high-accuracy evaluation as compared with the case where the device condition is selected based on comparison with the reference image.

Figure 22 is a diagram 2200 for plotting the evaluation values (e.g., pixel dispersion) obtained from the frame image of Figure 20. The plot point 2210 is the evaluation value of the image 2000 of FIG. 20, and the plot point 2211 is the evaluation value of the image 2010. Hereinafter, the evaluation point of the image 222020 is plotted in the same manner, the drawing point 2213 is the evaluation value of the image 2030, the drawing point 2214 is the evaluation value of the image 2040, and the drawing point 2215 is the evaluation value of the image 2050. The evaluation value becomes larger as the pattern is gradually brightened by the irradiation with the electron beam (2211, 2212), and when the electron beam is sufficiently irradiated, it is known that the change in the evaluation value is saturated (2213, 2214, 2215).

The evaluation value (for example, the luminance integrated value) obtained from the difference image of Fig. 21 is plotted in Fig. 23. The plot point 2310 is the evaluation value of the image 2110 of FIG. 21, and the plot point 2311 is the evaluation value of the image 2120. Hereinafter, the plot point 2312 is an evaluation value of the image 2130, the plot point 2313 is an evaluation value of the image 2140, and the plot point 2314 is an evaluation value of the image 2150. Immediately after the start of the electron beam irradiation, the change of the image is The evaluation values of the large plot point 2310 and the plot point 2311 become large values. It is known that the second half of the saturation of the image (plot point 2312, plot point 2313, plot point 2314) is slowly converged into a certain evaluation value.

The procedure for detecting the position of the guide pattern and the DSA hole pattern by using the evaluation value grasped by the separation of the bulk copolymerized polymer by the irradiation of the electron beam is shown in FIG.

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

The scanning, image acquisition, and evaluation value calculation are repeated in accordance with the conditions related to the threshold value predetermined for the evaluation value of each image (S2406). When the evaluation value and the critical value are in accordance with the determination condition, an integrated image is created (S2407). In the case of FIG. 22, the frame images 2030, 2040, and 2050 related to the evaluation values 2213, 2214, and 2215 of the section 2250 which becomes the frame number of the threshold value 2240 or more are outputted as an average image.

When the evaluation value obtained from the difference image of FIG. 23 is used, the interval after the number of frames 2330 which becomes the critical value 2340 or less is output. The frame images 2030, 2040, and 2050 included in the 2350 are used to calculate the average image.

In other words, in the example of Fig. 24, the number of frames until the contraction amount is equal to or less than a predetermined value is used for shrinking a specific polymer and monitoring the passer, and the signal obtained by the subsequent frame becomes a supply. The integrated object used to form the image for measurement. Such a condition is stored in advance in the memory medium provided in the control device or the like in association with the type of the DSA pattern, so that appropriate device conditions corresponding to the target pattern can be read later.

The method for detecting the center of the guide pattern and the center of the DSA hole pattern will be described below. First, in FIG. 22, a difference image of the evaluation values 2310, 2311, 2312 of FIG. 23 corresponding to the section 2260 which is the number of frames of the threshold value 2240 or less or the frame section 2360 which becomes the threshold value 2340 or more of FIG. 23 is created. The image 2500 of Fig. 25 is calculated. The edge 2502 of the guide pattern portion and the portion of the DSA hole pattern portion 2503 whose luminance value is changed by the electron beam irradiation are large as the pattern edge, and the luminance becomes high.

The cumulative addition image 2500 from the difference image is detected for the center position of the hole pattern (S2408). The detection at the center position can detect the edge of the guide pattern and the edge of the DSA pattern by the center of gravity and the generalized Hough transform after the large-sized object is extracted (S2409) (S2410). The continuity of the edge can also be used as an evaluation value by analyzing the large-sized object of the binary. Alternatively, the differential intensity is calculated from the spatial differentiation of the image, and the variability of the differential intensity at the edge position is taken as the evaluation value. Use the continuity of the edge and the variability of the differential intensity as the evaluation value. The method can also be applied to line patterns. In addition, the cumulative value of the Hough space can be used as an evaluation value according to the generalized Hough transform.

In the method of detecting the center of the hole pattern, the center position of the hole pattern can also be detected by matching with a template of a pattern registered in advance. In this case, the image registered in advance is used as a template as an image of the image 2050 sufficiently irradiated with the electron beam.

The evaluation values illustrated in Fig. 22 are used in the case where the pixels are dispersed but the correlation value is intended to be used as an evaluation value in the case of performing template matching.

In the method for detecting the center of the hole pattern using the stencil, the edge contour 2601 generated from the design material and the image 2602 of the guide pattern before the polymer coating may be used for the stencil shown in FIG. When the design data is used, since it is the edge information of only the pattern, it is matched with the integrated difference image 2600 to detect the center position. In the case of using the guide pattern image before the polymer coating, the edge-emphasized image 2603 to which the differential filter of the Sobel filter or the like is applied is used as a template and matched with the difference image 2500 to detect the center position. After the center position is detected, the length measuring cursor (S2411) is configured, and the length measuring is performed (S2412). As shown in FIG. 20, when a plurality of patterns are included in the image, (S2409) to (S2412) are performed for all the patterns. By pre-registering the positional relationship between the center position and the length measuring cursor, it becomes possible to correctly set the length measuring frame for the edge portion of the hole to be the length measuring object.

Alternatively, the imaging conditions may be memorized in advance in the flow of FIG. 24, and the scanning may be performed while reproducing during the automatic operation. In this case, it will also become The frame number 2230 of the threshold value 2240 or less in FIG. 22 or the frame section 630 of the threshold value 2340 or more of FIG. 23 is converted into the number of frames and the number of frames converted as the imaging conditions.

FIG. 27 shows a case where the edge of the DSA pattern is emphasized to be weak and detected as difficult. First, only the guide pattern (2702) is edge-detected and the center of gravity of the guide pattern is obtained (2704), and the center of gravity is used as a reference to radially detect the edge of the DSA pattern (Fig. 27). When the angle direction is the horizontal axis and the radial direction is the vertical axis and the drawing is as 2705, the undulation of the edge can be evaluated by detecting the fluctuation of the wave. In the case of unstable edges, the variability of the edge position is large as shown by 2705, but as the edges of 2706 and 2708 are gradually stabilized, the edge changes are slow (2707, 2709). By monitoring the variability of the edges in this way, the image integration can be started after the pattern is gradually stabilized.

With regard to the measurement of the DSA pattern described so far, an example of a user interface for setting parameters required for measurement is shown in FIG. The evaluation value threshold value is set as a threshold value for setting the number of integrated calculations in Fig. 22 (2230) and Fig. 23 (2330). In the case of automatic determination, the automatic (2802) is checked, and the threshold value (2803) is set by the hand movement setting system. The number of frames is the number of integrated frames of the measurement images set in FIG. 22 (2250) and FIG. 23 (2350). In the case of automatic execution, the setting is automatic (2805), and in the case of manual execution, manual setting (2806) is performed. In the pattern information (2807), the minimum allowable size of the guide pattern (2808), the DSA pattern (2809), the maximum allowable size, the tolerance of the center of gravity deviation of the guide pattern and the DSA pattern are set. (2810). If the values are outside the allowable range, the pattern size and the amount of deviation can be monitored immediately as a measurement error.

101‧‧‧矽 wafer

102‧‧‧ Guide pattern

110‧‧‧Composite polymer materials

111‧‧‧ polymer

112‧‧‧ polymer

Claims (24)

A pattern determining method for performing sizing of a pattern formed on a sample based on detection of charged particles obtained by scanning a charged particle beam of a sample, characterized by: based on irradiating charged particles for self-assembly lithography a polymer compound in the technique, wherein a specific polymer among a plurality of polymers forming the polymer compound is substantially shrunk relative to other polymers or simultaneously with shrinkage, in a region containing the other polymer, by a charged particle beam Scanning the resulting signal while performing the edge-to-edge sizing of the plural of the other polymers described above. The method for measuring a pattern according to the first aspect of the invention, wherein the brightness of an edge portion of the specific polymer is obtained based on detection of a signal obtained by scanning the charged particle beam, and the charging is performed based on the brightness information. The irradiation of the particles ends or the measurement of the charged particle beam is started. The method for measuring a pattern according to the second aspect of the invention, wherein the detecting of the signal is performed by a detector disposed obliquely with respect to the charged particle beam. The method for measuring a pattern according to claim 1, wherein the charged particles for shrinking the specific polymer are charged particles different from the charged particle beam or the charged particle source from which the charged particle beam is discharged. Charged particles emitted by the source. The method for determining a pattern according to claim 4, wherein the different charged particle source has a surface parallel to the sample surface A planar electron source on the surface. A charged particle beam device performs size measurement of a pattern formed on a sample based on detection of charged particles obtained by scanning a charged particle beam on a sample, and is characterized in that: a memory medium is provided, and an irradiation of charged particles is memorized The irradiation condition is that the charged polymer is irradiated onto the polymer compound used in the self-assembly lithography technique to substantially shrink the specific polymer among the plurality of polymers forming the polymer compound with respect to other polymers. Irradiation conditions; and control means for performing edge-to-edge dimensioning of the plurality of other polymers based on a signal, the signal being included after or after being irradiated with charged particles based on conditions stored in the memory medium The region of the other polymer is obtained by scanning a charged particle beam. The charged particle beam device according to claim 6, wherein the control device obtains a brightness of an edge portion of the specific polymer based on detection of a signal obtained by scanning the charged particle beam, based on the brightness Information, the irradiation of the charged particles is completed, or the measurement of the charged particle beam is started. The charged particle beam device according to claim 7, wherein the charged particle beam is provided with a detector in an oblique direction, and the control device starts the irradiation of the charged particles based on an output of the detector. Performing or lending the measurement of the charged particle beam. The charged particle beam device of claim 6, wherein the charged particles for shrinking the specific polymer are charged by the charged particle beam or from a charged particle source emitting the charged particle beam. Charged particles emitted by the particle source. The charged particle beam device of claim 9, wherein the different charged particle source is a planar electron source having a surface parallel to the surface of the sample. A device condition setting method for a charged particle beam device, which sets a scanning condition for scanning a sample with a charged particle beam, characterized by: scanning a charged particle beam based on a polymer compound used in a self-assembly lithography technique When the charged particles are obtained to form an image, the charged polymer beam is scanned by the charged particle beam, and the image obtained by the scanning is evaluated, and the scanning and image evaluation of the charged particle beam is repeated until the evaluation is performed. The result is that the scanning condition of the charged particle beam before the scanning for obtaining the integrated image is set as the scanning condition under the predetermined condition. The device condition setting method of the charged particle beam device of claim 11, wherein the image obtained by the scanning is a difference image of the image acquired in a different frame. For example, the charged particle beam device of claim 11 The condition setting method, wherein the image obtained by the scanning is a frame scanned by one frame, the first one, or the last one, and the image of the one frame, the previous one When the difference between the images of the next frame or the predetermined value is equal to or less than the predetermined value, it is determined that the predetermined condition is met. The device condition setting method of the charged particle beam device according to the first aspect of the invention, wherein the charged image is obtained based on the scanning after scanning after the scanning of the predetermined condition. The device condition setting method of the charged particle beam device of claim 11, wherein the image obtained by the scanning is a difference image of the image obtained in different frames, and the difference image is integrated to form an integrated difference. image. The device condition setting method of the charged particle beam device of claim 15, wherein the center of the hole pattern is detected based on the integrated difference image. The apparatus condition setting method of the charged particle beam apparatus of claim 11, wherein the length measuring frame for measuring the pattern is set based on the detection of the center of the hole pattern included in the image. A charged particle beam device comprising a scanning deflector for scanning a charged particle beam emitted from a charged particle source, and a detector for detecting charged particles obtained by scanning the charged particle beam of the sample, And a control device for integrating the output of the detector to form an image, wherein the control device repeats the evaluation of the scanning and image of the charged particle beam by evaluating the image obtained by scanning the charged particle beam. The scanning condition of the charged particle beam before the scanning for the integrated image acquisition is set as the scanning condition of the charged particle beam when the evaluation result meets the predetermined condition, and the evaluation result meets the predetermined condition. The charged particle beam device of claim 8, wherein the image obtained based on the scanning is a difference image of the image obtained in a different frame. The charged particle beam device of claim 18, wherein the image obtained by the scanning is an image obtained by scanning a frame, a front one, or a rear frame, the control device, When the difference between the image of the one frame and the image of the previous one or the next frame is equal to or less than a predetermined value, it is determined that the predetermined condition is satisfied. The charged particle beam device of claim 18, wherein the control device forms an integrated image based on the charged particles obtained by scanning after scanning according to the predetermined condition. For example, the charged particle beam device of claim 18, wherein The image obtained based on the scan is a difference image of the image acquired in different frames, and the control device integrates the difference image to form an integrated difference image. The charged particle beam device of claim 22, wherein the control device detects the center of the hole pattern based on the integrated difference image. The charged particle beam device of claim 18, wherein the control device sets a length measuring frame for measuring the pattern based on detection of a center of the hole pattern included in the image.