KR101753669B1 - Method for pattern measurement, method for setting device parameters of charged particle radiation device, and charged particle radiation device - Google Patents

Abstract

An object of the present invention is to provide a pattern measuring method and a charged particle beam apparatus capable of measuring and inspecting a pattern formed by the DSA technique with high precision. In order to achieve the above object, a polymer compound used in a self-organizing lithography technique is one in which a specific polymer is shrunk to a large extent from other polymers among a plurality of polymers forming the polymer compound by irradiating charged particles A pattern measuring method for measuring the dimension between a plurality of edges of the other polymer on the basis of a signal obtained by scanning a charged particle beam on a region containing the other polymer or a charged particle beam apparatus for realizing the measurement I suggest.

Description

Technical Field [0001] The present invention relates to a method of measuring a pattern, a method of setting a device condition of a charged particle beam device, and a charged particle beam device, and a charged particle beam device,

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

In recent semiconductor devices, the formation of a mask pattern for etching using a Directed Self-Assembly (DSA) method has been studied for generating a finer pattern. In the DSA method, a self-alignment property of a composite polymer material in which two kinds of polymers are connected or mixed is used. Patent Document 1 describes an example in which a pattern formed by the DSA technique is observed by a scanning electron microscope or an example in which a dimension of a pattern is measured.

It is expected that a charged particle beam device capable of measuring and inspecting fine patterns represented by a scanning electron microscope (SEM) will 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 after the characteristics of the sample are visualized.

Patent Document 4 discloses a technique in which, when performing pattern measurement by an electron microscope, an image is formed by integrating a plurality of pieces of image data, and the number of frames to be subjected to the integration is determined based on whether pattern recognition is possible Based on the judgment of the above-mentioned method.

Japanese Patent Application Laid-Open No. 2010-269304 (corresponding to U.S. Patent No. 8,114,306) Japanese Patent Application Laid-Open No. H10-313027 (corresponding US Patent No. 6,091,249) Japanese Patent Application Laid-Open No. 2006-234789 (corresponding US Patent No. 7,683,319) Japanese Patent Application Laid-Open No. 2010-092949 (corresponding US Patent Publication No. US2011 / 0194778)

The DSA technique is a technique in which a pattern is formed by coating a fine pattern formed by a general lithography method on a wafer so as to fill a polymer compound in which a plurality of types of polymers are chemically bonded, and separating the polymer by heat treatment. It is possible to perform fine patterning beyond the limit of reduction exposure by optical proximity effect. However, since the surface of the polymer compound after the heat treatment is flat, a scanning electron microscope which detects secondary electrons generated mainly by the edge effect There is a case that the contrast can not be sufficiently obtained. Patent Document 1 discloses observing a pattern formed by the DSA technique using an electron microscope but does not describe a specific method of how to improve the contrast. In Patent Documents 2 and 3, there is no disclosure about the observation of a pattern formed by the DSA technique.

Hereinafter, a pattern measuring method and a charged particle beam apparatus, which are firstly aimed at measuring or inspecting a pattern formed by the DSA technique with high precision using a high contrast image or a signal, will be described.

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

On the other hand, in the case of measuring a pattern separated by aniline using an electron microscope or the like, it is also possible to detect a pattern edge capable of being measured with little irregularity of the pattern in the state after the induction-structured state by the block copolymer or the blended polymer It is also difficult to do. It is also difficult to set an appropriate measurement range or irradiation time. Particularly, in a semiconductor manufacturing process, it is necessary to determine device conditions in advance in a charged particle beam device for evaluating the build of a pattern. Patent Document 1 does not describe in detail how such device conditions are determined. Patent Document 4 discloses a method of automatically determining the number of frames of image data to be integrated. However, there is no specific means for solving the problem of how to set the device condition when measuring a pattern having almost no unevenness.

On the other hand, the inventors confirmed that a specific polymer shrinks upon irradiation of a charged particle beam. Normally, among the plurality of separated polymers, the polymer which shrinks upon irradiation of the beam is the polymer on the side to be removed by development, so that if the beam condition is appropriately set, A high-precision measurement can be performed.

Hereinafter, it is a second object of the present invention to carry out highly precise pattern measurement or inspection based on appropriate device condition setting even if there is no unevenness like the DSA pattern and it is difficult to measure or inspect by the scanning of the charged particle beam using the edge effect , And a charged particle beam device will be described below.

In order to achieve the first object, a method of irradiating charged particles to a polymer compound used in a self-organizing lithography technique to increase a specific polymer among a plurality of polymers forming the polymer compound A pattern measurement method for carrying out measurement of a dimension between a plurality of edges of the other polymer on the basis of a signal obtained by shrinking or shrinking and a signal obtained by scanning a charged particle beam in a region containing the other polymer, To the charged particle beam device.

In order to achieve the second object, a scanning condition of a charged particle beam at the time of forming an image based on charged particles obtained by scanning a charged particle beam on a polymer compound used in a self-organizing lithography technique is set Wherein the charged particle beam is scanned with respect to the polymer compound and an image obtained on the basis of the scanning is evaluated. When the result of the evaluation satisfies the predetermined condition, The charged particle beam is scanned and the evaluation of the image is repeated and the scanning condition when the image satisfies the predetermined condition is set as the scanning condition of the charged particle beam before scanning for obtaining the image for accumulation, We propose a device condition setting method of the device.

A detector for detecting charged particles obtained by the scanning of the charged particle beam with respect to the sample; and a control unit for accumulating the output of the detector to form an image Wherein the control device evaluates an image obtained based on the scanning of the charged particle beam and performs a scanning operation of the charged particle beam and a scanning of the charged particle beam until the evaluation result satisfies a predetermined condition. Wherein the evaluation of the image is repeated and the scanning condition of the charged particle beam when the evaluation result satisfies the predetermined condition is set as a scanning condition of the charged particle beam before scanning for acquisition of the image for integration, Device.

The irradiation condition is for contraction of a specific polymer before image signal acquisition, which is used for image formation for measurement or inspection, for example. After the specific polymer is shrunk, beam scanning for measurement or inspection, or image acquisition .

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

According to the second configuration, even if there is no unevenness like the DSA pattern and it is difficult to measure or inspect by the scanning of the charged particle beam using the edge effect, it is possible to perform the measurement of the high- Inspection becomes possible.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing an example of a pattern formed by the DSA method; Fig.
2 is a schematic view of a scanning electron microscope;
3 is a view showing a relationship between a cross section of a DSA pattern and an SEM image;
4 is a view showing a relationship between an SEM image formed on the basis of the cross section of the DSA pattern and the output of the oblique detector.
Fig. 5 is a view showing four rectangular detectors. Fig.
6 is a view showing a four-way detector comprising detection elements divided into four elements;
7 is a view showing an example of a scanning electron microscope having a working electron source.
8 is a view showing an example of a planar electron source.
9 is a view showing an example of arrangement of a planar electron source.
10 is a view showing an example of arrangement of a planar electron source.
11 is a view showing an example of arrangement of a planar electron source.
12 is a view showing an example of a scanning electron microscope having a planar electron source.
13 is a view showing the trajectory of electrons when a machining beam is irradiated.
14 is a flowchart showing a process from the processing of the DSA pattern to the measurement of the DSA pattern.
15 is a diagram showing an example of a GUI screen for setting the preliminary irradiation conditions.
FIG. 16 is a table showing an example of a table storing preliminary irradiation conditions according to the types of patterns provided for each preliminary irradiation purpose; FIG.
17 is a view showing an example of a pattern dimension measuring system including a scanning electron microscope.
18 is a schematic view of a scanning electron microscope.
19 is a view showing an example of a DSA hole pattern image having a guide pattern;
20 is a frame image showing a shape in which a guide pattern and a DSA hole pattern are imaged when an electron beam is irradiated.
Fig. 21 is a diagram showing a difference (difference) image of front and rear frame images; Fig.
22 is a graph plotting the evaluation values obtained from the frame image group (group) in Fig.
23 is a graph plotting evaluation values obtained from the group of difference images in Fig.
Fig. 24 is a flowchart showing a measurement process using an integrated image. Fig.
25 is a diagram showing an example of an image obtained by integrating a difference image;
26 is a view for explaining a method of detecting a center of a hole pattern using a template;
27 is a view for explaining a detection method of a guide pattern;
28 is a diagram showing an example of a GUI screen for inputting measurement parameters;

Fig. 1 schematically shows a fine pattern obtained by the DSA method. 1 (a) shows a silicon wafer 101 serving as a substrate for pattern generation. 1 (b), a wide pitch pattern 102 that is wider than the repetition pitch of the desired fine pattern is formed by the lithography technique on 101. FIG. Thereafter, the composite polymer material 110 is applied in Fig. 1 (c). By appropriate heat treatment (anil), 110 aligns itself in a specific direction with pattern 102 as a guide. 110 is composed of repetitions of two kinds of different polymers 111 and polymers 112. 1 (d), a narrow pitch pattern 103 having a narrower pitch than the guide pattern 102 can be generated by selectively removing one polymer (for example, 112).

It is important to determine whether or not the phase separation has been appropriately performed before the heat treatment and after the heat treatment in order to know early whether or not the appropriate polymer material is selected and whether the conditions for the non-thermal treatment are appropriate. However, As described above, although the polymer material contains a plurality of polymers, the surface is flat, so that a high-contrast image can not be obtained by the scanning electron microscope. Based on the above-described situation, the inventors newly found that one of the structures that the SEM for inspecting and measuring DSA patterns should have is a surface treatment for contrast enhancement. In the measurement or inspection of the pattern, it is important to detect the defects of the pattern as soon as possible because it is possible to reduce the time and economic cost, and it is important that the step of FIG. 1 (c) Is preferable. In this state, there is no difference in height between the polymer 111 and the polymer 112, and it is difficult to conduct a normal SEM observation. Further, there is no large difference in the mass density between the polymer 111 and the polymer 112, and contrast due to the difference in mass density can not be obtained. In addition, since the electrical characteristics of the polymer 111 and the polymer 112 are often the same as each other, the potential contrast due to the difference in charging potential can not be obtained.

The embodiment described below provides a method and an apparatus for observing a charged particle beam in advance before irradiating the observed region for observing a narrow pitch pattern generated by the DSA method. It is possible to reduce the volume of one of the pair of polymers (111 and 112 in Fig. 1) by irradiating charged particle lines in advance to the observed region. This method makes it possible to form a step according to the pattern shape on the surface of the polymer, and to perform measurement and inspection with high accuracy. It is to be noted that the charged particle beam irradiated beforehand in the observed region is the same as the charged particle beam used for the subsequent observation.

Example 1

An example of a scanning electron microscope capable of measuring a high contrast signal of a DSA pattern based on a high contrast signal will be described with reference to the drawings. Fig. 2 shows a schematic view of a scanning electron microscope (SEM). The electron source 201 is held at a negative potential with respect to the specimen by the control power source 231. [ The drawing electrode 202 is set to a static potential higher than the electron source 201 by a positive voltage power source 232 superimposed on the control power source 231 to draw out 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. [ The amount of current of the electron beam 220 is detected by the Faraday cup 205 and measured by the current measuring means 235. The electron beam 220 scans an observation field of view with a deflector 207 operated by a deflection control circuit 237. When the electron beam 220 is retracted from the sample 210, the blanker 204 is operated using the blanker power supply 234. Signal electrons generated from the sample 210 are detected by an in-lens detector 206 provided on the side of the electron source 201 rather than the objective lens 208 or a four-sided detector 209 provided in a specific direction. In lens detector provides a detector suitable for obtaining an edge contrast image that emphasizes the edge of the surface step difference by efficiently detecting low speed signal electrons emitted from the sample in various directions. On the other hand, the four-sided detector 209 is suitable for detecting high-energy signal electrons emitted in a specific direction of the sample.

In observing the pattern formed by the DSA method, the observation sample 210 is placed on the sample stage 211 and is transported below the objective lens 208. The observation site is previously scanned by the electron beam 220, and the volume of the one polymer is reduced to form the surface step difference. We call this process an investigation for machining. Thereafter, the observed region is scanned again with the electron beam 220, and the signal of the in-lens detector 206 is imaged by the signal processor 236 to obtain a microscopic 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 kinds of polymers in the resulting microscopic image. By using this edge line, measurement of the pattern dimension on the specimen to be inspected can be performed with high accuracy, or defects of the pattern shape on the specimen to be inspected can be inspected.

It is preferable that a polymer compound used for a self-organizing lithography technique is irradiated with charged particles to greatly shrink the specific polymer from a plurality of polymers forming the polymer compound to another polymer, According to the above configuration in which the dimension measurement is performed between a plurality of edges of the other polymer based on a signal obtained by the scanning of the beam, the DSA pattern can be quickly evaluated with high accuracy.

17 is a diagram showing an example of a pattern measurement system including an SEM 1701. The system mainly includes a SEM 1701, a control device 1702 for controlling the SEM 1701, An optical condition setting device 1703 for setting the device condition, and a setting device 1704 for setting the measurement condition by the SEM. A GUI (Graphical User Interface) screen as shown in Fig. 15, for example, can be displayed on the display device provided in the setting device 1704. [ An input window 1501 for inputting a type of a pattern and an input window 1502 for inputting a beam irradiation condition before beam scanning for measurement are provided on the GUI screen illustrated in Fig. In the case of this embodiment, a voltage contrast, a contact hole observation (C / H) Observation, an edge emphasis (Edge) emphasizing the edge of the other polymer by decreasing the volume of the above- Enhancement), it is possible to select a pre-scan mode.

In the preliminary scanning of the potential contrast mode, beam scanning by beam condition for charging elements included in the visual field is performed (first scanning mode). In the preliminary scanning in the contact hole observation mode, beam scanning for positively charging the resist on the surface of the sample is performed (second scanning mode). In the preliminary scanning of the edge emphasis mode, scanning is performed to reduce one polymer (third scanning mode).

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

As described above, there are various types of preliminary scanning, and the beam conditions are different from each other. For example, as shown in Fig. 16, a database for storing beam conditions for each pattern type is prepared for each scanning mode, And the beam condition can be read based on the selection of the scanning mode, the selection of the preliminary scanning condition becomes easy. In addition, by preparing such a database and updating the condition when the unknown sample is measured, the past setting conditions can be easily set. (FOV), an exposure time (Exposure Time), a beam current (Beam Current), a landing energy of a beam to a sample, And the number of frames, the type of the pattern, and the selection of the preliminary scanning mode to update the database as shown in Fig.

The database is registered in the memory 1705 incorporated in the optical condition setting device 1703 and set as the optical condition of the SEM 1701 according to the setting by the setting device 1704. [ An optical condition setting unit 1707 that sets a beam condition for measurement, a database registered in the memory 1705, or a setting unit 1704 that is set by the setting unit 1704 is provided in the calculation processing unit 1706 provided in the optical condition setting apparatus 1703. [ A preliminary irradiation condition setting unit 1708 for setting a preliminary scanning condition, a brightness condition extracting unit 1709 for obtaining a condition for stopping the preliminary irradiation described later, and a beam scanning unit for measuring a profile And a pattern measuring unit 1710 for measuring the dimension of the pattern.

According to the above configuration, it is possible to perform measurement using edges that are currently processed based on machining with high accuracy.

3 is a view 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 (image) before irradiation for processing are performed. There is no contrast on the SEM corresponding to the absence of the surface step difference between the two kinds of polymers 301 and 302. [ FIG. 3 (b) shows a case where the volume of the polymer 302 is reduced by beam irradiation. A large number of signal electrons are generated from the side wall of the polymer 301 that has not been reduced in volume to form a strong signal region (white band) 303 at the boundary between the polymer 301 and the polymer 302. Thus, the DSA pattern can be measured and inspected. Fig. 3 (c) shows the case where the method of the present 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 contacting the portion where the endmost polymer 302 is not filled, the white band 303 of the pattern edge at which the sufficient processing has been performed is insufficient in processing It can be seen from the enlarged view of the pattern of Fig. 3 that the signal of the pattern edge 304 is weak.

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

Fig. 14 is a flowchart showing a process from machining to measurement. The following processing is executed by controlling the SEM 1701 by the control device 1702 based on the setting condition set by the optical condition setting device 1703. [ First, beam scanning is performed to confirm whether machining and machining are properly performed (step 1401), and a profile for machining 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 larger than the predetermined value, beam scanning for dimension measurement is performed (step 1404). A profile is formed based on the charged particles obtained as a result of beam scanning in step 1404 (step 1405), and the dimension measurement of the pattern using the formed profile is performed (step 1406).

Unlike the case where a specific element is selectively electrified, since the brightness signal of the edge and the other portions are relatively different as the preliminary irradiation progresses, the transition of the relative difference between the edge portion and the other portions is evaluated An appropriate machining end point can be obtained. Further, the luminance information may not be a comparison of peak heights, but may be a variation of a peak width, for example. In addition, the profiles formed for dimension measurement do not include the profile signal for the process monitor, so that the dimension measurement can be performed with high accuracy.

As described later, when charged particle detection for process monitoring and charged particle detection for pattern size measurement are performed at the same time, a signal after completion of processing may be selectively used at the time of formation of the profile for measurement, And the output signal of the detector may be received after the termination.

4 is a diagram showing an image formed on the basis of the charged particles detected by the four-sided detector 209 arranged in the oblique direction with respect to the beam optical axis, as shown in Fig. In the image by the four-sided detector 209, the slope of the sample toward the normal direction toward the detector is bright, and the sample surface toward the normal direction in the direction opposite to the detector becomes dark. In other words, the edge having the cross-section facing the detector side becomes brighter, and the edge having the cross-section opposite to the detector side becomes dark.

4A is an SEM image of the DSA pattern before beam irradiation for processing. Since there is no surface step difference between the two kinds of polymers 401 and 402, no contrast is given even if it is the SEM image based on the detection of the four-way detector. 4B and 4C are SEM images when the volume of the polymer 402 is reduced by processing by beam irradiation.

Of the sidewalls of the polymer 401 that have not been reduced in volume, the sidewall portions facing the direction of the four-sided detector or a portion of the polymer 402 are bright, and the sidewalls in the opposite direction and a portion of the polymer 402 are imaged dark. In Fig. 4, the brightness 403 of the upper portion of the polymer, the brightness 404 of the cross section facing the detector side when sufficient processing is performed, The luminance 405 of the cross section facing the detector side when the processing is insufficient, the luminance 406 of the cross section facing the detector side when the processing is insufficient, and the luminance 406 of the cross section facing the detector side when the processing is insufficient 407) in different display formats.

The larger the difference in brightness between the bright portion and the darker portion, the deeper the surface step is, and the smaller the difference in brightness is, the smaller the surface step is, so that it is possible to judge whether the irradiation for processing is sufficient by using the image of the four- More specifically, the control device forms a histogram in which the horizontal axis represents the luminance and the vertical axis represents the detection number based on the signal outputs of the four-way detectors arranged in a specific direction, and the histogram of the two peaks in the histogram having the predetermined luminance It can be considered that when the luminance difference becomes equal to or larger than the predetermined value, it is judged that the machining is completed. Further, since the cross section facing the detector side becomes brighter as the machining proceeds, it may be judged that the machining is completed when the brightness of the edge portion of the detector side is equal to or larger than the predetermined value. However, since the brightness of the edge portion varies depending on the shape of the cross section or the material of the polymer, the method of performing the determination based on the contrast between the brightness of the dark portion and the brightness of the bright portion can more accurately detect the end of the machining .

By performing the end-of-machining detection with high accuracy, high-precision measurement can be realized without prolonged measurement or excessive beam irradiation. Further, by separately providing a detector for measurement and a detector for processing monitor, it is possible to shift from measurement to measurement immediately after processing.

In the above-described determination of the amount of processing, it is assumed that the direction of the sidewall of the pattern does not always coincide with the direction of the four-sided detector. As the four-way detector, a plurality of four-way detectors corresponding to different orientations may be provided. Fig. 5 shows an example in which independent four-sided detectors are arranged in four directions. The signal electrons 501a, 501b, 501c, and 501d generated from the sample 210 by the electron beam 220 are detected by the four-way detectors 502a, 502b, 502c, and 502d, respectively. Alternatively, a detection element (semiconductor detector, multi-channel plate, Abalancer type photodiode, CCD) in which a detector having a single detection surface is divided into plural parts may be used. Fig. 6 is an example of a four-way 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 in accordance with the emitting direction.

Further, in order to more efficiently perform irradiation for processing, it is possible to use a lens control circuit 233 or 238 so as to have a diameter on the sample different from the electron beam at the time of observation. It is also possible to irradiate with the control power source 231 at an energy different from that of the electron beam at the time of observation. Likewise, the current amount, the scanning speed, the scan area, and the like can be set differently from the time of observation in order to perform the processing efficiently.

Example 2

In the description so far, mainly, the beam for measurement or the beam for which the beam condition of the beam for measurement is changed is used to perform processing before the measurement. Hereinafter, a beam source for measurement, which is different from the beam source for measurement, Are provided in the charged particle beam apparatus, and processing is performed using the different beam sources.

In this embodiment, an example in which a working beam source is formed parallel to a sample surface in order to irradiate a processing beam from a direction perpendicular to the sample surface will be described. It is necessary to arrange the beam source for processing in a position other than the beam trajectory emitted from the beam source for measurement in order to arrange the beam source for processing in the charged particle beam apparatus. For example, in the case where the beam source for processing is disposed at an inclined position 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 unevenly removed, There is a possibility that an error occurs.

It is also conceivable to bend the beam introduced from four directions by a deflector to guide the beam to the observed region in order to irradiate the beam perpendicularly to the observed region. However, the deflector for bending generally has aberration And therefore, when the surface treatment and the observation are performed at the same time, degradation of the resolution is caused. The deterioration of the resolution may lower the measurement accuracy of the narrow pitch pattern measurement.

Further, if another electron source such as a flood gun is prepared, there is a possibility that the vacuum chamber becomes larger.

In the present embodiment, a configuration in which the first charged particle beam used for observation and the second charged particle beam irradiated beforehand in the observed region are not the same 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 simultaneously performed will be described. The discharge source (first charged particle source) of the first charged particle beam will also be described as an example in which the emission source of the second charged particle beam (second charged particle source) and the particle beam optical axis thereof are the same.

By making the optical axes the same, it is possible to irradiate and process charged particles without deviation with respect to the narrow pitch pattern, and also to carry out processing and observation without moving the sample, thereby miniaturizing the vacuum chamber. Further, the beam emitted from the radiation source of the working beam is perpendicular to the sample surface, and the working beam and the measuring beam are coaxial, so that it is possible to perform processing and measurement without degradation of resolution due to deflection of the deflector .

According to this embodiment, it is possible to provide a charged particle beam device capable of recognizing a molecular boundary with high visibility even in the case of an arrangement of molecular polymers having no surface step formed by the DSA method and having a small difference in mass density. In addition, it is possible to efficiently and homogeneously reduce the volume of the polymer in a short time while maintaining the resolution, and high-precision inspection and measurement of the fine pattern becomes possible.

A specific example of this embodiment will be described below with reference to the drawings. Fig. 7 shows a schematic view of a scanning electron microscope (SEM). The electron source 701 is maintained at a negative potential with respect to the sample by the control power source 731. [ The lead electrode 702 is set to a potential higher than the electron source 701 by the constant voltage power source 732 superimposed on the control power source 731 to draw out the electron beam 720. The electron beam 720 is irradiated onto the observation sample 710 via 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 scans an observation field of view by a deflector 707 which is operated by a deflection control circuit 737. When the electron beam 720 is retracted from the sample 710, the blanker 704 is operated by using the blanker power supply 734. The signal electrons generated from the sample 710 are detected by the detector 706, and are image-formed by the signal processor 736 to obtain microscopic images.

A planar electron source 709 is arranged between the sample 710 and the objective lens 708 and its operation is controlled by a control power source 739. [ It is assumed that the surface-shaped electron source is exclusively irradiated with a DSA pattern for processing. The planar electron source 709 shares an optical axis with the electron source 701 for observation. 8 shows a specific form of the coplanar surface-shaped electron source 709. In Fig.

The planar electron source 709 is a disk-shaped circular ring having a hole at the center. In particular, it is considered that the two electron sources 709 and 701 are arranged coaxially by having the central hole and the electron beam 720 having a common axis. Since the vicinity of the observation site of the sample 710 can be uniformly processed, the outer diameter of the planar electron source 709 does not impair the characteristics of the present invention even if it is other than circular. As shown in Fig. 8, the planar electron source 709 is made up of a discharge surface 802 and a drawing surface 803. [0086] The control power source 739 has a high voltage power source 805 for determining the acceleration voltage of the planar electron source 709 and a high voltage power source for drawing out the electron beam and determining the potential difference between the drawing plane 803 and the emitting plane 802 806).

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 not so large. In this case, as shown in Fig. 9, a four-sided detector 901 may be provided outside the plane-shaped electron source 709. [ Particularly, as described in the first embodiment, since the edge detection of the observation pattern by the four-sided detector is important, the four-sided detector 901 can be used as the main detector.

Alternatively, a planar electron source 709 may be provided on the electron source 701 side of the objective lens 708 and the detector 706 as shown in Fig. With this configuration, efficient detection of the signal electrons 1001 can be realized. In this case, there is a possibility that the angle at which the planar electron source 709 faces the sample 710 becomes narrow, and the amount of electrons irradiated 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 to be added separately.

Alternatively, as shown in Fig. 11, the arrangement height of the planar electron source 709 may be arranged to be the same as the focal point 1102 of the signal electrons 1101. The focal point 1102 is sufficiently small and can pass through the hole in the center of the planar electron source 709. [ This method makes it possible to arrange the planar electron source 709 closer to the sample 708 than to the detector 709 and efficiently guide the irradiation current to the sample 710. [

Example 3

Other embodiments will be described with reference to the drawings. Fig. 12 shows a schematic view of a scanning electron microscope (SEM). The electron source 1201 is maintained at a negative potential with respect to the observation specimen 1211 by the control power source 1231. [ Let the potential of the electron source 1201 with respect to the sample 1211 be VP (<0). The lead electrode 1202 is set to a potential VP1 higher than the electron source 1201 by a constant voltage power source 1232 superimposed on the control power source 1231 to draw out the electron beam 1220. [ The electron beam 1220 is irradiated onto the sample 1211 via 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. [ The amount of current of the electron beam 1220 is detected by the Faraday cup 1205 and measured by the current measuring means 1235. The electron beam 1220 scans an observation field of view with a deflector 1207 operated by a deflection control circuit 1237. When the electron beam 1220 is retracted 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 provided on the side of the electron source 1201 or by a four-way detector 1214 provided in a specific direction from the objective lens 1208, 1236 or 1244) to obtain a microscopic image. An energy filter 1213 is disposed between the four-sided 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 supply 1239. The potential of the plane-shaped electron source 1209 with respect to the sample 1211 is VF. Further, the plane-shaped electron source 1209 has a mesh-like drawing plane 1210. The potential VF1 of the drawing surface 1210 with respect to the planar electron source 1209 is controlled by the high voltage power source 1240 superimposed on the control power source 1239 on this drawing surface 1210. [ The electron beam irradiated from the planar electron source 1209 to the sample 1211 exclusively irradiates the DSA pattern for processing. It is also possible in principle to provide 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 irradiated area is large and deflection of the electron beam by the blanker is difficult, a method of sufficiently reducing the potential difference (VF) or reducing the number of electrons reaching the sample with a positive value, or a method of reducing the potential difference (VF1) Or a negative value to reduce the number of electrons emitted from the planar electron source 1209 is used.

Next, with reference to Fig. 13, a method for simultaneously irradiating the electron beam for machining with the planar electron source 1209 and acquiring the SEM image will be described. Fig. 13 shows details of the planar electron source and the rectangular detector shown in Fig. 12. Fig. Also, it is not absolutely necessary to use a four-sided detector, and a similar configuration by the in-lens detector 1206 is also possible.

Not only the electron beam 1220 but also the electron beam 1303 irradiated for the processing also generates the signal electrons 1304 from the sample 1211 when the irradiation for processing and the acquisition of the SEM image are performed at the same time. The spatial resolution of the SEM image is determined by the diameter of the electron beam 1220 on the sample 1211. Since the spatial spread 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 machining can not provide a high spatial resolution, When the signal electrons are simultaneously detected, the resolution of the SEM image deteriorates. 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 (VP <VF).

The kinetic energy that the electron beam 1220 for observation has when it enters the sample 1211 becomes larger than the kinetic energy that the electron beam 1303 for processing has when it enters the sample 1211. [ Therefore, the maximum energy EP of the signal electrons generated by the electron beam 1220 for observation necessarily becomes larger than the maximum energy EF of the signal electrons generated by the electron beam 1303 for processing (EP> EF) .

Next, when the threshold voltage Eth of the energy filter 1213 is selected to be such that EP > Eth> EF, the signal electrons 1305 after the filter detected by the four-way detector 1214 are reflected by the electron beam 1220 for observation, And electrons generated by the electrons. By the above-described method, it is possible to efficiently perform processing and observation at the same time without deteriorating the image quality.

Example 4

The embodiments described below mainly relate to a charged particle beam apparatus that scans charged particle beams onto a sample pattern and performs inspection or measurement of the specimen. The sample pattern to be observed is a contact hole or via pattern in which the block copolymer and the blended polymer are formed by induction-hardening in the guide pattern.

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 the respective layers. Vias and contact holes are used for various connections such as transistors and circuit wirings in the lower layer, other elements, circuit wirings, and wirings. In a conventional process for manufacturing a via pattern or a contact hole, a method of sequentially performing lithography and etching at a position and a size determined by design data is generally used. With the latest immersion lithography and dry etching, it is possible to form a via pattern of about 30 nm, but it is difficult to use conventional optical lithography to resolve a via pattern after a 22 nm node. Various problems such as double exposure, super resolution, EUV exposure and electron beam exposure have been addressed with respect to the fundamental problem of miniaturization of semiconductor device patterns. However, at present, there is a demand for mass production in terms of manufacturing cost and technology level Not satisfied.

Patterning techniques using inductive organization by a block copolymer or a blended polymer can form a fine pattern without using an expensive exposing device. Particularly in the formation of the DSA hole using a hole pattern as a guide, it is possible to generate a fine hole pattern while controlling the position of the pattern.

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

A polymer component (for example, PMMA or the like), which is liable to react with the charged particle beam, is patterned by the shrinking phenomenon by irradiating the charged particle beam in place of the development in the state after the induction. In this way, a DSA pattern image locally separated even by the inspection apparatus for irradiating the charged particle beam before development can be obtained.

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

If there is no problem with the evaluation result, the development process is performed, and the hole pattern is formed through the etching process. If the evaluation result is not good, rework is performed or the conditions of the manufacturing apparatus of the previous step are changed to form a pattern again. Thus, information obtained by measurement or evaluation of fine hole patterns by the charged particle beam can be fed back to the manufacturing apparatus, thereby improving the yield and quality of the semiconductor process.

In a charged particle beam device used for inspection of a semiconductor process such as a length measuring SEM, it is necessary to determine the number of scanning frame frames in advance for automatic operation. In the pattern of the DSA process, it is possible to observe the pattern edge by irradiating the electron beam. However, since the interaction between the charged particle beam and the polymer component such as the shrinking phenomenon is generally unstable, it is difficult to determine the integrated frame number uniquely Do. For this reason, it is difficult to detect the pattern position by template matching using the registered template.

Due to the characteristics of the charged particle beam device in this method, the signal noise ratio is low, and it is difficult to detect the pattern edge by separating the signal and noise by a small addition signal.

In the DSA process, as described above, if the charged particle beam is not irradiated for a predetermined period of time, the image is not stable, and therefore it is difficult to determine the optimum electron beam irradiation time before image acquisition.

Even in the case of pattern detection using the registered template, the pattern observed in the DSA process is liable to be changed by irradiation of the charged particle beam, so that there is a possibility of causing the positional shift.

It is required to measure and monitor the positional deviation of the guide pattern and the formed DSA pattern in the DSA process.

In the following embodiments, the charged particle beam is scanned in the state after the induction-hardening by the block copolymer or the blended polymer, the pattern position is recognized based on the information obtained from the charged particles emitted from the injection point and the evaluation reference, The scanning electron microscope will be described. A method of determining the conditions such as the number of integrated frames based on evaluation values by grasping changes in signals and images from the pattern of the DSA process by irradiating with an electron beam will be described.

An example of detecting the measurement range and the pattern position by appropriately combining the evaluation value with the signal intensity, the luminance change of the image, the edge sharpness (edge degree), and the edge continuity is also described.

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

An example in which the edge of the guide pattern or the time at which the luminance of the DSA pattern is stable is determined by grasping the change of the signal or the image from the pattern of the DSA process.

An example of registering a pseudo image generated from an etched guide pattern image or design data as a template without using an unstable pattern signal of the DSA process and registering the template to detect the pattern is also described do.

According to the above configuration, the position of the pattern can be recognized and measured in the state after the induction and organization by the block copolymer or the blended polymer. In this method, the measurement range is automatically set.

An appropriate number of frames and a pre-dose time can be determined when capturing the pattern of the DSA process during the automatic operation of the charged particle beam apparatus. In addition, stable pattern position detection and measurement can be performed by using a plurality of evaluation values. In addition, false detection of the pattern can be reduced by measuring the noise level from the image at the initial stage of DSA pattern charge particle irradiation and separating the pattern edge signal and noise.

When automatic operation is performed by registering a template, a guide pattern image after etching or a pseudo image generated from design data is registered as a template and used for pattern detection, thereby enabling stable pattern detection.

18 is a block diagram of a configuration outline of a scanning electron microscope. The overall control unit 1825 controls the electron optical system control unit 1826 and the stage control unit 1827 based on the acceleration voltage of the electrons inputted by the operator from the user interface 1828, the information of the wafer 111, The control of the entire apparatus is performed. The wafer 1811 is fixed on the stage 1812 in the sample chamber 1813 after passing through the sample exchange chamber through a sample transfer device not shown.

The electro-optical system control unit 1826 controls the high voltage control unit 1815, the first condenser lens control unit 1816, the second condenser lens control unit 1817, the secondary electron signal amplifier 1818 ), An alignment control section 1819, a deflection signal control section 1822, and an objective lens control section 1821. [

The primary electron beam 1803 drawn out from the electron source 1801 by the drawing electrode 1802 is converged by the first condenser lens 1804, the second condenser lens 1806 and the objective lens 1810, ). The electron beam passes through the aperture 1805 and its orbit is adjusted by the alignment coil 1808 and is supplied to the deflection coil 1809 receiving the signal from the deflection signal controller 1822 through the deflection signal amplifier 1820 The sample is then scanned two-dimensionally. The secondary electrons 1814 emitted from the sample 1811 are captured by the secondary electron detector 1807 and the secondary electron signal is amplified by the secondary electron signal amplifier 1818 due to the irradiation of the primary electron beam 1803 to the wafer 1811. [ And is used as a luminance signal of the secondary electron image display 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.

Further, in order to create an image used for dimension measurement of the pattern, a signal output from the secondary electronic signal amplifier 1818 is subjected to A / D conversion in an image processing processor 1823 to generate digital image data. Also, a secondary electron profile is created from the digital image data. In the present embodiment, image data to be integrated, which will be described later, is selected by using a computing device such as the image processing processor 1823. [ In some cases, the control unit is simply referred to as a control unit, including a computing unit and a control unit.

The range to be measured from the created secondary electron profile is automatically selected based on a manual or a predetermined algorithm, and the number of pixels in the selected range is calculated. The actual dimensions on the sample are measured from the actual dimensions of the observation area scanned by the primary electron beam 1803 and the number of pixels corresponding to the observation area.

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

19 shows a schematic diagram 1900 of a typical pattern image used for DSA hole pattern measurement with a guide pattern. The schematic diagram 1900 of the DSA hole pattern image includes DSA hole patterns 1901, 1902, 1903, and 1904 having four guide patterns. The hole patterns 1911, 1912, 1913, and 1914 serving as guides are generally formed by a lithography process and an etching process by a conventional optical exposure apparatus. Typically, the DSA hole patterns 1921, 1922, 1923, and 1924 are induced and organized by applying a block copolymer or a blended polymer and then separating the polymer in the annealing process. Thereafter, one polymer is removed by development, and an etching process is performed to complete the patterning. However, instead of the phenomenon after induction-hardening, a polymer (for example, PMMA or the like) that easily reacts with an electron beam by irradiating an electron beam can see the edge of the DSA hole even by the shrinking phenomenon. As described above, a DSA pattern image separated only locally (only at the inspection point) can be obtained by an inspection apparatus that irradiates an electron beam before development. In the following, block copolymers are described, but the same applies to blended polymers.

FIG. 20 is a schematic diagram showing an image on a frame-by-frame basis in which a DSA hole is imaged when an electron beam is irradiated on a DSA hole pattern coated with a block copolymer. (2000, 2010, 2020, 2030, 2040, 2050) in which the guide pattern and the DSA hole pattern gradually appear from the image 2000 before the electron beam irradiation. In the image 2000 immediately after irradiating the electron beam, the guide pattern and the DSA hole can hardly be observed. The edge 2052 of the guiding pattern hole and the bottom portion 2053 of the DSA hole pattern after the block copolymer is separated can be observed clearly in the image 2050 in which the electron beam is sufficiently irradiated. Here, the figure is shown for each frame image of the hole pattern, but in the case of the line pattern, it may be a signal profile for each line scan. It is also possible to use an image in which a frame is added and averaged several times.

21 is an image obtained by calculating the difference between front and rear images in the image for each frame described in Fig. The difference image 2120 is obtained by subtracting 2100 from the frame image 2110 and likewise the difference image 2120 from the frame image 2120 and the difference image 2130 from the frame image 2130 to 2120 I am subtracting it. The difference image 2150 is obtained by subtracting the frame image 2040 from the frame image 2050. However, the luminance value is close to zero. This indicates that there has been almost no change in the frame image 2050 and the frame image 2040. [ In this patent, this change is detected, and the number of frames, the position of the guide pattern, and the position of the DSA pattern are detected. By comparing the plurality of images extracted in the process of beam scanning for the same object, it is possible to select appropriate apparatus conditions. A plurality of images obtained by different frame numbers are basically the same object, and so-called autocorrelation evaluation is performed. For example, it is possible to perform a high-precision evaluation in comparison with a case in which a reference image is prepared in advance and a device condition is selected based on a comparison with the reference image.

FIG. 22 is a graph 2200 plotting an evaluation value (for example, pixel dispersion) obtained from the frame image of FIG. The plot point 2210 is an evaluation value of the image 2000 in Fig. 20, and the plot point 2211 is an evaluation value of the image 2010. Fig. 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, Is an evaluation value of the image 2050. As the pattern is gradually irradiated with the electron beam, the evaluation value becomes larger (2211, 2212), and when the electron beam is sufficiently irradiated, the change in the evaluation value is saturated (2213, 2214, 2215).

FIG. 23 shows an evaluation value (for example, luminance integrated value) obtained from the difference image in FIG. 21 plotted. The plot point 2310 is an evaluation value of the image 2110 in FIG. 21, and the plot point 2311 is an evaluation value of the image 2120. 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 irradiation of the electron beam, the change in the image is large, and therefore the evaluation values of the plot point 2310 and the plot point 2311 are large. (Plot point 2312, plot point 2313, and plot point 2314), in which the change of the image saturates, gradually converges to a constant evaluation value.

FIG. 24 shows a procedure for detecting the position of the guide pattern and the DSA hole pattern by using an evaluation value for grasping the shape in which the block copolymer is separated by the irradiation of the electron beam.

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 imaging conditions such as magnification (S2402), an image is acquired while scanning the electron beam (S2403) (S2404). The acquired image is transmitted to the image processing processor 1823, and the image processing processor 1823 calculates an evaluation value for each image (S2405). For example, the evaluation value uses the image variance value or the sum of the pixel values of the differential image. The target region may be an entire pixel value or may be calculated by selectively using the pixel value of the edge portion after recognizing the pattern.

The calculation of the scan, the image acquisition, and the evaluation value is repeated according to the condition for the threshold value determined in advance for the evaluation value of each image (S2406). When the evaluation value satisfies the determination condition with respect to the threshold value, the integrated image is generated (S2407). In the case of FIG. 22, an image obtained by adding and averaging the frame images 2030, 2040, and 2050 for the evaluation values 2213, 2214, and 2215 of the frame number section 2250 exceeding the threshold value 2240 is output.

When an evaluation value obtained from the difference image shown in Fig. 23 is used, an image obtained by adding averages of the frame images 2030, 2040, and 2050 included in the section 2350 after the frame number 2330 which is equal to or less than the threshold value 2340 Output.

That is, in the example of Fig. 24, the number of frames until the amount of shrinkage becomes equal to or less than a predetermined value is for shrinking the specific polymer and for monitoring the progress thereof, To be integrated. By storing these conditions in a storage medium provided in the control device or the like in association with the type of the DSA pattern, it becomes possible to read appropriate device conditions according to the target pattern later.

Next, a method of detecting the center of the guide pattern and the center of the DSA hole pattern will be described. 22, the evaluation values 2310 and 2311 shown in FIG. 23 for the frame interval 2260 of the threshold value 2240 or less or the frame interval 2360 equal to or larger than the boundary value 2340 of FIG. 23 , And 2312 in the image 2500 shown in Fig. A portion where a change in the luminance value by electron beam irradiation is large, such as the edge 2502 of the guide pattern portion and the DSA hole pattern portion 2503, becomes high as a pattern edge.

The center position of the hole pattern is detected from the accumulated image 2500 of the difference image (S2408). In order to detect the center position, the edge of the guide pattern and the edge of the DSA pattern can be separately detected (S2409) (S2410) by the center of gravity after the blob extraction and the generalized Hough transform. It is also possible to use the continuity of the edge as an evaluation value by analyzing the blob. It is also possible to calculate the differential intensity from the spatial differential of the image and use the deviation of the differential intensity at the edge position as the evaluation value. The method of using the continuity of the edge and the deviation of the differential intensity as the evaluation value can be applied to the line pattern. According to the generalized Hough transform, the accumulated value of the Hough space can be used as the evaluation value.

As another method of detecting the center of the hole pattern, the center position of the hole pattern may be detected by matching with a template of a previously registered pattern. In this case, the image to be registered in advance uses the same image as the image 2050 after sufficiently irradiating the electron beam as a template.

The evaluation value described in Fig. 22 is pixel dispersion, but in the case of performing template matching, the correlation value may be used as the evaluation value.

As another method for detecting the center of a hole pattern using a template, an edge contour 2601 generated from design data or an image 2602 of a guide pattern before polymer application may be used for a template as shown in Fig. In the case of using the design data, since only the edge information of the pattern is obtained, the center position is detected by matching with the accumulated difference image 2600. Even when a guide pattern image before polymer application is used, the center position is detected by matching with the difference image 2500 using the edge emphasized image 2603 to which a differential filter such as a Sobel filter is applied as a template. After detecting the center position, a depth-of-field cursor is arranged (S2411) and the depth 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 the patterns. By previously registering the positional relationship between the center position and the measurement cursor, it is possible to accurately set the measurement box at the edge portion of the hole to be measured.

In the flowchart of Fig. 24, the imaging conditions may be stored in advance, and the scan may be performed in the automatic operation mode. In this case, from the frame number 2230 of the threshold value 2240 or less of the threshold value 2240 or the frame interval 630 of the threshold value 2340 of FIG. 23 or more, It is also possible to make the condition.

Fig. 27 shows detection of a case where the edge strength of the DSA pattern is weak and detection is difficult. First, only the guide pattern 2702 is edge-detected and the center of gravity of the guide pattern is determined (2704), and the edge of the DSA pattern is radially detected with reference to the center of gravity (FIG. 27). When a graph is drawn with the angular direction as the abscissa and the radial direction as the ordinate, 2705 is obtained. By detecting the bending of this wave, it is possible to evaluate the deviation of the edge. If the edge is not stable, the deviation of the edge position is large like 2705, but when the edge becomes stable as shown by 2706 and 2708, the change of the edge becomes gentle (2707, 2709). By monitoring the deviation of the edge in this manner, it is possible to start image integration after the pattern is stabilized.

28 shows an example of a user interface for setting the parameters necessary for measurement with respect to the measurement of the DSA pattern described so far. The evaluation value threshold value is set as a threshold value for setting the number of integrated starts in Figs. 22 (2230) and 23 (2330). If the automatic determination is to be executed, a check is made to Auto (2802), and the threshold value is set to be manually set (2803). The number of frames sets the total number of frames of the measurement image in Figs. 22 (2250) and 23 (2350). Set Auto (2805) to run automatically, or Manual (2806) if run manually. In the pattern information 2807, the guide pattern 2808, the minimum allowable size of the DSA pattern 2809, the maximum allowable size, and the center of gravity tolerance value 2810 of the guide pattern and the DSA pattern are set. When these values are out of the allowable range, if the measurement error is detected, the pattern size and shift amount can be monitored in real time.

101: Silicon wafer
102: guide pattern
110: composite polymer material
111: polymer
112: polymer
201: Electronic circle
202: lead electrode
203: focusing lens
204: blanker
205: Faraday Cup
206: In-lens detector
207: deflector
208: Objective lens
209: Four-way detector
210: observation sample
211: sample stage

Claims (24)

A pattern measuring method for carrying out dimensional measurement of a pattern formed on a sample based on detection of charged particles obtained by scanning a charged particle beam on a sample,
The present inventors have found that a polymer compound used in a self-organizing lithography technique can be obtained by shrinking a specific polymer from a plurality of polymers forming the polymer compound by irradiating charged particles to a great extent with respect to another polymer, Wherein measurement of the dimension between a plurality of edges of said another polymer is performed based on a signal obtained by scanning of the charged particle beam in an area including said another polymer. The method according to claim 1,
Determining the luminance of the edge portion of the specific polymer on the basis of the detection of the signal obtained by scanning the charged particle beam and terminating the irradiation of the charged particles or the measurement by the charged particle beam based on the luminance information And the pattern is measured. 3. The method of claim 2,
Wherein the detection of the signal is performed by a detector provided in an inclined direction with respect to the charged particle beam. The method according to claim 1,
Wherein the charged particles for shrinking the specific polymer are charged particles emitted from the charged particle beam or a charged particle source different from the charged particle source for emitting the charged particle beam. 5. The method of claim 4,
Wherein the other charged particle source is a planar electron having a plane parallel to the surface of the sample. A charged particle beam apparatus for carrying out dimensional measurement of a pattern formed on a sample based on detection of charged particles obtained by scanning a charged particle beam on a sample,
A storage medium storing irradiation conditions of charged particles for shrinking a specific polymer to a large amount of other polymers among a plurality of polymers forming the polymer compound by irradiating charged particles with a polymer compound used in a self-organizing lithography technique; On the basis of a signal obtained by scanning a charged particle beam on a region containing the other polymer after irradiating the charged particle or on shrinkage based on the conditions stored in the storage medium, And a control device for carrying out dimension measurement. The method according to claim 6,
The control device calculates the luminance of the edge portion of the specific polymer on the basis of the detection of the signal obtained by scanning the charged particle beam, and based on the luminance information, Wherein the measurement of the charged particle beam is started. 8. The method of claim 7,
Wherein the controller is provided with a detector in an oblique direction with respect to the charged particle beam, wherein the control device is configured to execute the end of irradiation of the charged particles or start the measurement by the charged particle beam based on the output of the detector Characterized in that the charged particle beam device comprises: The method according to claim 6,
Wherein the charged particles for shrinking the specific polymer are charged particles emitted from the charged particle beam or a charged particle source different from the charged particle source for emitting the charged particle beam. 10. The method of claim 9,
Wherein the other charged particle source is a planar electron having a plane parallel to the surface of the sample. delete delete delete delete delete delete delete delete delete delete delete delete delete delete

Images