JP2012073073A - Method and apparatus for inspecting defect of pattern shape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for inspecting a shape defect of patterned media, enabling inspection of the whole area throughout the total number of patterned media manufactured in the order of one sheet per a few seconds.SOLUTION: In a method for inspecting a repeated pattern formed on a substrate and having a dimension of 100 nm or less, a substrate is irradiated with light containing a plurality of wavelength components, reflected light from the substrate irradiated with the light is spectrally diffracted and detected, a signal obtained by the spectral diffraction and the detection is processed and a spectral reflection factor is obtained, an evaluation value is calculated from the obtained spectral reflection factor, and a pattern shape defect is determined from the evaluation value calculated from the spectral reflection factor based on a pre-obtained relationship between a evaluation value and a pattern cross-sectional shape.

Description

  The present invention relates to a method for inspecting a cross-sectional shape of a pattern having a line width of 100 nm or less formed on a substrate, and more particularly to a pattern shape defect inspection for inspecting a pattern cross-sectional shape of a patterned media or a semiconductor device as a next-generation hard disk medium. The present invention relates to a method and an apparatus thereof.

The recording capacity of hard disk drives has been increasing in recent years. However, with a so-called continuous medium in which a magnetic film is simply formed on a conventional disk substrate, the recording density is limited to about 1 Tbit / in2, and the introduction of patterned media is planned as a technology to achieve higher recording density. Has been.
As shown in FIG. 1, a patterned medium is a discrete track medium that forms recording tracks 102 concentrically on the surface of a disk 101, and a bit that is formed as an island pattern 103 with independent recording units (bits). Two methods of patterned media are being studied. In either case, unlike the conventional continuous medium, there is a feature that a pattern with a pitch of several tens of nm is formed on a disk medium.

  Therefore, unlike a conventional manufacturing process, a process for forming a pattern is newly added, and there is a concern that a defect due to the process occurs. For example, FIG. 2 is a diagram schematically showing a cross section of a pattern, but the defect is that the pattern cross-sectional shape is deformed 202 or the pattern itself is missing 203 compared to the normal pattern 201. Is considered.

  As means for inspecting defects of such patterns, means such as an atomic force microscope (hereinafter abbreviated as AFM) and a scanning electron microscope (hereinafter abbreviated as SEM) are used. In addition, there is an optical inspection method called so-called scatterometry. AFM and SEM are techniques known in the art.

  In general, the scatterometry is performed by detecting the spectral reflectance 303 on the surface of the inspection target 302 with the spectral detection optical system 301 as shown in FIG. 3 and then on the surface of the inspection target 302 based on the detected spectral reflectance 303. This refers to a technique for detecting the cross-sectional shape of the uniformly formed repeating pattern 304. Utilizing the fact that the cross-sectional shape of the uniformly formed repeating pattern is different, the spectral reflectance of the surface is also different, and the shape of the repeating pattern uniformly formed on the inspection target surface from the spectral reflectance of the inspection symmetrical surface Can be detected. The theoretical value (model) calculated using the structure and material to be inspected is obtained by optimizing the parameters so as to coincide with the actually detected spectral reflectance using the shapes such as height and width as parameters. For parameter optimization, methods such as model fitting and library matching are used.

  Scatterometry, which is an optical method, has a feature that inspection can be performed at a higher speed than AFM and SEM. Patent Document 1 below discloses an inspection method capable of measuring an accurate shape of a pattern using scatterometry and having a large throughput.

JP 2009-150832 A

  Patterned media is manufactured by forming a pattern with a line width of several hundreds of nanometers or less on the surface of a substrate (substrate) by deposition of a magnetic material or the like, nanoimprinting, etching or the like. At this time, the time required for each process is about several seconds / sheet. For example, when the total number is to be inspected, it is similarly required to inspect within several seconds / sheet.

  As described above, by using AFM, SEM, or scatterometry, the cross-sectional shape of a pattern having a line width of several hundred nm or less formed on the substrate can be inspected. However, when the present method is used, only about one area having a size of about several tens of μm on the disk surface can be inspected within the time.

  As described above, scatterometry can be inspected at a higher speed than SEM and AFM, but this method requires several seconds to measure one point (an area of about several tens of μm). This is because the method of detecting the shape uses a method with a large calculation amount such as model fitting or library matching described above, and it is difficult to further reduce the calculation time even in library matching with a relatively small calculation amount. is there. For this reason, it is not impossible to inspect the entire area as long as the area that can be inspected is limited, but it is impossible to inspect the entire disk within the predetermined time.

  An object of the present invention is to provide a pattern shape defect inspection method and its apparatus for patterned media, which makes it possible to inspect the entire surface of the patterned media produced at several seconds / sheet.

  In order to achieve the above object, in the present invention, in a method for inspecting a repetitive pattern having a dimension of 100 nm or less formed on a substrate, the substrate is irradiated with light containing a plurality of wavelength components, and the substrate irradiated with this light is irradiated. Spectral detection of the reflected light, and processing the signal obtained by the spectral detection to obtain the spectral reflectance, calculate the evaluation value from the obtained spectral reflectance, the evaluation value obtained in advance The pattern shape defect is determined from the evaluation value calculated from the spectral reflectance based on the relationship between the pattern cross-sectional shape and the pattern sectional shape.

  In order to achieve the above object, according to the present invention, a pattern shape defect inspection apparatus for detecting a repetitive pattern with a dimension of 100 nm or less formed on a substrate includes a θ stage for mounting the substrate and rotating the substrate. A stage unit including an X stage for moving the substrate in one direction, a light irradiation unit for irradiating the substrate with light including a plurality of wavelength components, and spectroscopic light reflected from the substrate irradiated with light by the light irradiation unit And a data processing unit that detects a shape defect of a pattern formed on the substrate by processing a signal obtained by spectral detection using the spectral detection optical system. The data processing unit is obtained by a spectral reflectance calculation processing unit that obtains a spectral reflectance by processing a signal obtained by spectral detection with a spectral detection optical system, and a spectral reflectance calculation processing unit. Evaluation value from spectral reflectance A shape parameter calculation processing unit that calculates a shape parameter from an evaluation value calculated from the spectral reflectance based on a relationship between an evaluation value obtained in advance and a pattern cross-sectional shape, and a determination stored in advance And a shape defect determination processing unit that detects a shape defect of a pattern formed on the substrate from the shape parameter calculated by the shape parameter calculation processing unit using the threshold value.

  According to the present invention, the calculation amount of the pattern shape calculation is very small compared to the scatterometry, and the pattern shape can be calculated almost simultaneously with the detection of the spectral reflectance. As a result, it has become possible to inspect the entire surface of the patterned media produced at several seconds / sheet.

It is a perspective view which shows the outline | summary of a patterned media. It is sectional drawing which shows the outline | summary of the defect of a patterned media. It is a block diagram which shows the structure outline | summary of a scatterometry. It is sectional drawing of the type | mold and board | substrate which show a pattern formation process. It is sectional drawing which shows the cross-sectional shape of a magnetic body pattern. It is sectional drawing which shows the cross-sectional shape of a resist pattern. It is a perspective view which shows two patterns from which a shape differs. It is a graph which shows the spectral reflectance of two pattern surfaces from which a shape differs. It is a graph which shows the relationship between a pattern width and the reflectance in a certain wavelength. It is a block diagram which shows the schematic structure of an inspection apparatus. It is a front view which shows the schematic structure of a stage system. It is a block diagram which shows the schematic structure of a detection optical system. It is a front view which shows the structure of the spectrometer of a detection optical system. It is a front view which shows the schematic structure of the reflective objective lens of a detection optical system. It is a block diagram which shows the schematic structure of another example of a detection optical system. It is explanatory drawing which shows the flow of data processing. It is explanatory drawing which shows the sequence of a test | inspection. It is a front view of the screen which displays a test result. It is a front view which shows another example of defect map display among the screens which display a test result.

  In the present invention, by applying a scatterometry technique, the correlation between the spectral reflectance of the sample surface and the shape such as the width and height of the pattern is evaluated in advance, and from the value of the spectral reflectance actually detected, Shapes such as pattern width and height are calculated by a relatively simple calculation.

  As an embodiment of the present invention, a case where the present invention is applied to inspection of HDD patterned media will be described.

  Unlike the conventional media as described above, the patterned media forms a magnetic pattern on the disk surface (see FIG. 1). FIG. 4 is a diagram schematically showing the pattern forming process. First, a resist 402 is applied on the magnetic layer 403 (a). A mold 401 having a fine pattern 4011 formed on the surface is pressed against the applied resist 402 (b). Exposure is performed in this state, and the shape of the fine pattern 4011 is transferred to the resist 402 (c). The magnetic body 403 under the concave portion 4022 is etched using the convex portion 4021 of the transferred resist pattern as a mask to form a pattern of the magnetic body 403 on the disk (e). Finally, the resist is removed (f). Such a pattern formation method is called nanoimprint technology. In FIG. 4, the magnetic body 403 is described as a single-layer structure for the sake of simplicity, but in actuality, it is formed in multiple layers.

  A hard disk medium records information by magnetizing a magnetic material formed on a substrate. Therefore, the amount of the magnetic material on the disk substrate is one factor that affects the performance as a recording medium.

  Consider traditional media as an example. When the film thickness of the magnetic layer is smaller than a certain value, recording by magnetization can be performed, but the recorded information cannot be read because the leakage magnetic field from the magnetic body becomes small.

  The same applies to patterned media. FIG. 5 is a diagram schematically showing a magnetic pattern. A pattern 501 in FIG. 6A is a normal pattern having an appropriate width W1, and the pattern 501 is a plurality of layers such as a surface protective film layer 5011, a magnetic film layer 5012, a first underlayer 5013, and a second underlayer 5014. It is configured. If the width W2 of the pattern 502 is small as shown in FIG. 5B, the amount of the magnetic film layer 5012 is small, so that writing can be performed as described above, but reading may not be possible, resulting in a failure. If the width W3 of the pattern 503 is too large as shown in c), the signal of the adjacent track is detected as noise, which may be defective in this case. As described above, the shape of the magnetic material pattern after pattern formation becomes a factor that determines the performance as a recording medium.

  Processes that require pattern shape inspection are the resist pattern after imprinting and the magnetic pattern after etching and embedding and planarization, but the shape of the magnetic pattern is mainly determined by the shape of the resist pattern (Fig. 4), it is most efficient to inspect the shape of the resist pattern.

  FIG. 6 is a view schematically showing a resist pattern, in which a resist pattern 602 is formed on the magnetic layer 601. At this time, the resist pattern 602 is not directly formed on the magnetic layer 601, but a resist layer 606 is formed between the magnetic layer 601 and the resist pattern 602. The shape to be detected of the resist pattern 602 is mainly a pattern width 603, height 604, and base film thickness 605. Hereinafter, a method of detecting these three parameters mainly for the resist pattern 602 will be described.

  In this method, each parameter of the shape is detected based on the reflectance of the surface. In that sense, it is a scatterometry technique. However, in this method, the pattern shape is directly calculated using the value of the spectral reflectance instead of detecting the shape by the above-described model fitting or the like. Specifically, the correlation between the spectral reflectance and the shape parameters such as height and width is evaluated in advance using a multivariate analysis method or the like, and an equation as shown in Equation 1 is prepared, and the reflection is applied to this equation. By inputting the rate value, the value of each shape parameter is calculated. The principle of this method will be described below.

図８は図７に示すパターン形状の異なるビットパターン７０１が形成された表面の波長が０．２μｍ〜０．８μｍ（２００ｎｍ〜８００ｎｍ）の光に対する分光反射率を示した図である。図７の（ａ）のような比較的大きなビットパターン７０１の場合には、図８のグラフの（ａ）のような分光反射率のパターンとなる。一方、図７（ｂ）のような比較的小さいビットパターン７０２の場合には、図８のグラフの（ｂ）のような分光反射率のパターンになる。この様にパターン形状が異なると、表面の反射率も変化する。

FIG. 8 is a diagram showing the spectral reflectance for light having a wavelength of 0.2 μm to 0.8 μm (200 nm to 800 nm) on the surface on which the bit patterns 701 having different pattern shapes shown in FIG. 7 are formed. In the case of a relatively large bit pattern 701 as shown in FIG. 7A, a spectral reflectance pattern as shown in FIG. 8A is obtained. On the other hand, in the case of a relatively small bit pattern 702 as shown in FIG. 7B, the spectral reflectance pattern as shown in FIG. 8B is obtained. When the pattern shapes are different in this way, the surface reflectance also changes.

  Here, attention is paid to a change in reflectance at a certain wavelength. FIG. 9 is a diagram showing a change in reflectance at a certain wavelength using the pattern width as a parameter. As shown in the figure, it can be seen that the reflectance value and the shape parameter are substantially proportional (linear).

  This phenomenon can be confirmed by each shape parameter such as the height and width of the pattern, and in the range where each shape parameter is about ± 10 nm, the reflectance and the shape parameter are in a proportional relationship (linear). Recognize. In the case of being linear in this way, the relationship between the spectral reflectance and each shape parameter can be expressed by the above equation (1).

  A method using regression analysis is conceivable as a method for generating Equation 1 representing the relationship between the spectral reflectance and each shape parameter. For example, it is conceivable to use a PLS (Partial least square) method which is one of multivariate analysis methods. Since the PLS method is a known method, description thereof is omitted here.

  Another multivariate analysis method such as PCR (Principal component regression) may be used. In short, it is sufficient that Formula 1 can be generated, and any means may be used.

  In addition, a method expressed by a multidimensional expression or other mathematical expression is also effective instead of the linear linear expression as shown in equation (1).

  Depending on the measurement target, a strong correlation (correlation coefficient close to 1) may not be obtained between the spectral reflectance and the shape parameter. When the correlation is weak, the error of the shape parameter value calculated from Equation 1 also increases. Therefore, in order to more strongly detect the correlation with the shape parameter, it is effective to perform appropriate processing (preprocessing) before multivariate analysis and use the value after processing (evaluation value).

  As an example of pre-processing, it is conceivable to set a reference spectral reflectance as a reference reflectance in advance, calculate a difference value from the reference reflectance at each wavelength, and use the difference value of the spectral reflectance (Equation 2 ). By setting the difference value, it is possible to obtain a stronger correlation with respect to the change of the parameter.

また、分光反射率の差分値データの値を、ある波長の差分値で正規化することが考えられる。具体的には、ある波長の差分値データと、各波長の差分値データとの比を算出する(数３)。この処理により、さらに強い相関関係を示すことができる。

Further, it is conceivable to normalize the value of the difference value data of the spectral reflectance with the difference value of a certain wavelength. Specifically, the ratio between the difference value data of a certain wavelength and the difference value data of each wavelength is calculated (Equation 3). By this processing, a stronger correlation can be shown.

前処理のもう一つの例としては、分光反射率の微分値を用いることが考えられる。微分値を求める手段としては、隣接する波長での反射率の差分値を求める方法(数４)や、ある波長での微分値として隣接する前後の反射率の差分値を用いる方法(数５)がある。微分値を求めることにより、同様に強い相関関係を示すことができる。

As another example of the preprocessing, it is conceivable to use a differential value of spectral reflectance. As a means for obtaining a differential value, a method of obtaining a difference value of reflectance at adjacent wavelengths (Equation 4), or a method of using a difference value of reflectance before and after adjacent as a differential value at a certain wavelength (Equation 5). There is. By obtaining the differential value, a strong correlation can be shown similarly.

前処理をする目的は、強い相関関係を検出することにあり、上記に限らず検査対象によって異なる前処理を適用すればよい。

The purpose of the preprocessing is to detect a strong correlation, and is not limited to the above, and different preprocessing may be applied depending on the inspection target.

  Next, a hard disk inspection apparatus using the above detection method will be described. FIG. 10 shows the configuration of a hard disk inspection apparatus using the detection method of the present invention. The inspection apparatus according to the present invention includes a spectroscopic detection optical system 1001 that irradiates detection light onto an inspection target disk (hard disk medium) 1005 that is an inspection target and spectrally detects reflected light from the inspection target disk 1005, and an inspection target that is an inspection target. A stage unit 1002 that can move the position relative to the optical system so as to hold the disc 1005 and perform spectroscopic detection at an arbitrary position on the disc, a control unit 1003 that controls the operation of the spectroscopic detection optical system 1001 and the stage unit 1002, and The data processing unit 1004 detects the shape or shape abnormality of the pattern formed on the surface of the inspection target disk 1005 that is the inspection target based on the spectral detection data detected by the light detection optical system 1001.

  FIG. 11 is a schematic diagram showing an example of the configuration of the stage unit 1002. As shown in the figure, the stage unit 1002 moves in the direction perpendicular to the inspection target disk 1005 and the X stage 1101 that moves parallel to the inspection target disk 1005. And a θ stage 1103 for rotating the inspection target disk 1005.

  The Z stage 1102 is for moving the inspection target disk 1005 that is the inspection target disk to the focus position of the spectral detection optical system 1001. The X stage 1101 and the θ stage 1103 are inspection target disks 1005 that are inspection target disks. This is for moving the spectroscopic detection optical system 1001 to an arbitrary position on the surface. As a method for moving the inspection target disk 1005, a method using an XY stage is also conceivable. However, since the shape of the inspection target is a disc shape and the pattern to be inspected is also formed concentrically, the Xθ stage is more preferable. Is suitable. For example, for the purpose of inspecting the entire surface of the disk 1005 to be inspected at high speed, it is efficient if the Xθ stage is moved simultaneously to spectrally detect the disk surface spirally.

  FIG. 12A is a diagram showing an example of the configuration of the spectral detection optical system 1001 according to the present invention. As shown in FIG. 1A, the detection optical system 1001 includes a light source 1201, a lens 1202, a half mirror 1203, a polarizing element 1204, an objective lens 1205, an imaging lens 1206, and a spectroscope 1207. Light emitted from the light source 1201 passes through the lens 1202, is reflected by the half mirror 1203, and changes its direction, and is irradiated to the inspection target disk 1005 that is the inspection target through the polarizing element 1204 and the objective lens 1205. . The reflected light from the inspection target disk 1005 irradiated with the light emitted from the light source 1201 passes through the objective lens 1205 and the polarizing element 1204 again, and half of the amount of the reflected light is transmitted through the half mirror 1203 and is reflected by the imaging lens 1206. The light is guided to the spectroscopic detector 1207.

  At this time, as shown in FIG. 12B, the field stop 1208 is arranged at the position of the entrance 12071 of the spectroscopic detector 1207 so that the field stop 1208 and the surface of the inspection target disk 1005 are in an imaging relationship by the imaging lens 1206. By setting the detector 12073 at a position conjugate with the field stop 1208 via the concave diffraction grating 12072, the region for spectral detection by the spectroscopic detector 1207 can be limited by the shape of the field stop 1208. For example, if the size of the entrance is φ600 μm and the magnification on the image plane is 20 times, the size of the spectral detection area is φ30 μm on the inspection target disk.

  As described above, when trying to use a wavelength near 200 nm, the applicable optical elements are limited. As the light source, a xenon lamp, a deuterium lamp, or the like that emits light having a wavelength of about 200 nm or more can be used. However, depending on the inspection target, sufficient performance may be exhibited even at a wavelength of about 400 nm or more. In that case, a light source that emits infrared light from visible light such as a halogen lamp may be used.

  In the optical system of the present embodiment, the objective lens 1205 uses a reflective objective lens 12050 in which a concave mirror 12051 and a convex mirror 12052 as shown in FIG. 12C are combined. There are almost no refraction type objective lenses composed of transmission type lenses that are generally used, and can be applied broadly from around 200 nm to visible light. The reflective objective lens 12050 includes a concave mirror 12051 and a convex mirror 12052, and can be used from a wavelength of about 200 nm.

  The spectroscope 1207 is usually commercially available, and one having a maximum sampling rate of several hundred kHz is generally available. In order to further increase the sampling rate, it is possible to apply a detector 12073 using a photomultiplier.

  The spectroscopic detection optical system 1001 shows a case where a broad wavelength band is dispersed, but a method of detecting light having a plurality of discrete wavelengths is also conceivable. For example, as shown in FIG. 13, the light emitted from a plurality of laser light sources 1301-1, 1301-2, and 1301-3 that emit lasers having different wavelengths is the same using the dichroic mirrors 1302-1 and 1302-2. The optical path is switched by a half mirror 1306 as detection light superimposed on the optical axis and irradiated to the sample 1005 via the polarizing element 1304 and the reflective objective lens 1305, and the reflected light from the sample 1005 is passed through the imaging lens 1306. Similarly, there is a method in which a plurality of detectors 1307-1, 1307-2, and 1307-3 are detected by separating each wavelength using dichroic mirrors 1308-1 and 1308-2. Although the figure shows the case where three lasers are used, the number of discrete wavelengths is not limited to three, and may be two or four or more.

  Next, defect determination processing is executed based on the calculated shape using the spectral waveform signals detected by the spectral detector 1207 or the detectors 1307-1 to 1307-3. As an example, there is a method in which a range to be determined as a non-defective product is determined for each shape parameter in advance, and a non-defective product is determined when the detected shape is within this range, and a defective product is determined when it is out of the range. The determination may be performed independently for each shape parameter, or may be performed in combination. For example, a method of determining by a product of height and width is also conceivable.

  Next, the operation of the inspection apparatus of the present invention will be described with reference to FIG. First, the inspection target disk 1005 is loaded (installed on the stage unit 1002) (S1401), and the center and direction are detected in advance as necessary (disk alignment) (S1402). Next, the Z stage 1102 is driven, and the inspection target disk 1005 is moved to the focus position of the detection optical system 1001 (S1403). Subsequently, the X stage 1101 and the θ stage 1103 are driven to move the inspection target disk 1005 so that the inspection position of the inspection target disk 1005 is directly below the detection optical system 1001 (S1404). In the inspection, the X stage 1101 and the θ stage 1103 are continuously driven under the set conditions (S1405), and in the driven state, the spectral reflection intensity on the surface of the inspection target disk 1005 is detected by the spectral detection optical system 1001. (S1406) The detected spectral reflection intensity signal is processed by the data processing unit 1004 to detect a pattern shape and detect a defect (data processing) (S1407). This is executed until the inspection is completed over the entire surface of the inspection target disk (S1408). When the inspection is completed, the X stage 1101 and the θ stage 1103 are stopped (S1409), and the inspection target disk is taken out (of the inspection target disk). Unload) (S1410). It should be noted that description regarding alignment of the inspection target disk 1005, installation on the stage, and removal is omitted.

When the control is performed by the control unit 1003 and the X stage 1101 and the θ stage 1103 are continuously operated to perform the inspection, the spiral area on the inspection target disk 1005 can be inspected. For example, when an operation in which the X stage 1101 moves by the detected spot size during one rotation of the θ stage 1103 is performed in the radial direction of the inspection target disk 1005, the entire disk surface can be inspected.
Details of the data processing executed by the data processing unit 1004 in S1407 are shown in FIG. Data processing is roughly divided into the following three types. The first is reflectance calculation processing S1510, the second is shape parameter calculation processing S1520, and the third is defect determination processing S1530.

First, in the reflectance calculation process S1510, the detection signal from the spectral detector 1207 is received to detect the spectral reflection intensity Is on the surface of the inspection target disk 1005 (S1511). On the other hand, the spectral intensity Ir of the mirror surface Si is detected in advance (S1512). Next, the ratio (relative reflectance R) of the spectral reflection intensity Is of the surface of the disk 1005 to be inspected to the spectral intensity Ir of the mirror surface Si is obtained. There is a case where the noise In is superimposed, which is also detected in advance, and the relative reflectance R is calculated by the following equation as a ratio of the subtracted values.
R = (Is-In) / (Ir-In)
Next, in the shape parameter calculation processing S1520, pre-processing is performed on the relative spectral reflectance R calculated in S1510 by the method using Equations 2 to 5 described above (S1521). On the other hand, the spectral reflectance is detected in advance with a sample of a known shape and a data set (plurality) combined with the shape parameter is prepared (S1522), and the spectral reflectance data of the detected sample of the known shape is prepared. On the other hand, preprocessing is performed in the same manner as in S1521 (S1523), and multivariate analysis (PLS analysis) is performed on the preprocessed data to correlate the evaluation value and the shape parameter as shown in Equation 1. An expression is obtained (S1524). Each shape parameter is calculated using the correlation equation between the evaluation value and the shape parameter obtained in advance and the relative spectral reflectance R preprocessed in S1521 (S1525).

  Finally, in the defect determination process S1530, a determination threshold value is set in advance (S1531), and based on each shape parameter calculated in S1525, it is determined based on the preset threshold value whether or not it is a shape defect. (S1532).

  FIG. 16A shows an example in which the determination result is displayed on the display screen 1600 of the data processing unit 1004. The display screen 1600 includes a defect map display area 1602 for displaying a defect map 1601 on the inspection target disk 1005, an area 1603 for displaying mold (mold) information, and an area 1604 for displaying the type of defect displayed on the defect map 1601. , An area 1605 for displaying the determination result is provided. In the example of FIG. 16A, defects are displayed as dots on the defect map 1601, but as shown in FIG. 16B, the distribution for each type of shape defect (in the example of FIG. 16B, pattern thickening 16011 and pattern thinning 16012) is a region. May be displayed. Similarly, parameters representing the pattern shape such as the width and height of the pattern may be displayed. In the example, the inspection result is shown in a disk shape as in the disk shape, but the display method is not limited to this.

  As described above, for example, the pattern shape / defect distribution of the patterned medium can be detected by the inspection apparatus of the present invention.

DESCRIPTION OF SYMBOLS 1001 ... Spectral detection optical system 1002 ... Stage part 1003 ... Control part 1004 ... Data processing part 1005 ... Inspection object disk
1101 ... X stage 1102 ... Z stage 1103 ... θ stage 1201 ... light source 1202 ... lens 1203 ... half mirror 1204 ... deflection element 1205 ... objective lens 12050 ... Reflective objective lens 1206 ... imaging lens 1207 ... spectrometer 1600 ... display screen.

Claims (10)

A method for inspecting a repetitive pattern having a dimension of 100 nm or less formed on a substrate,
Irradiating the substrate with light containing a plurality of wavelength components,
Spectrally detect the reflected light from the substrate irradiated with the light,
The spectral reflectance is obtained by processing the signal obtained by the spectroscopic detection,
An evaluation value is calculated from the obtained spectral reflectance,
A pattern shape defect inspection method comprising: determining a pattern shape defect from an evaluation value calculated from the spectral reflectance based on a relationship between an evaluation value obtained in advance and a pattern cross-sectional shape.   The pattern shape defect inspection method according to claim 1, wherein the relationship between the evaluation value obtained in advance and the pattern cross-sectional shape is obtained using a multivariate analysis method.   The pattern shape defect inspection method according to claim 1, wherein a difference value between the obtained spectral reflectance and a spectral reflectance of reflected light from a preset reference surface is used as the evaluation value.   As the evaluation value, a difference value between the obtained spectral reflectance and a spectral reflectance of reflected light from a preset reference surface is obtained, and a value normalized by a ratio with the reflectance at a specific wavelength is used. The pattern shape defect inspection method according to claim 1.   The pattern shape defect inspection method according to claim 1, wherein a differential value of spectral reflectance is used as the evaluation value. An apparatus for inspecting a repetitive pattern having a dimension of 100 nm or less formed on a substrate,
Stage means comprising a θ stage for placing the substrate and rotating the substrate; and an X stage for moving the substrate in one direction;
A spectroscopic detection optical system comprising: a light irradiation unit configured to irradiate the substrate with light including a plurality of wavelength components; and a detection unit configured to spectrally detect and detect reflected light from the substrate irradiated with light by the light irradiation unit. ,
A data processing unit that detects a shape defect of a pattern formed on the substrate by processing a signal obtained by spectral detection with the spectral detection optical system;
The data processing unit
A spectral reflectance calculation processing unit for processing a signal obtained by spectral detection with a spectral detection optical system to obtain a spectral reflectance;
The shape parameter is calculated from the evaluation value calculated from the spectral reflectance based on the relationship between the evaluation value obtained in advance and the pattern cross-sectional shape while calculating the evaluation value from the spectral reflectance obtained by the spectral reflectance calculation processing unit. A shape parameter calculation processing unit for calculating
A shape defect determination processing unit for detecting a shape defect of a pattern formed on the substrate from the shape parameter calculated by the shape parameter calculation processing unit using a determination threshold stored in advance; Pattern shape defect inspection device.   The pattern shape defect inspection apparatus according to claim 6, wherein the shape parameter calculation processing unit obtains a relationship between the evaluation value obtained in advance and a pattern cross-sectional shape using a multivariate analysis method.   The shape parameter calculation processing unit uses, as the evaluation value, a difference value between the spectral reflectance of the substrate obtained by the spectral reflectance calculation processing unit and the spectral reflectance of reflected light from a preset reference surface. The pattern shape defect inspection apparatus according to claim 6.   The shape parameter calculation processing unit obtains a difference value between the spectral reflectance of the substrate obtained by the spectral reflectance calculation processing unit and the spectral reflectance of reflected light from a preset reference surface as the evaluation value, 7. The pattern shape defect inspection apparatus according to claim 6, wherein a value normalized by taking a ratio with the reflectance at a specific wavelength is used.   The pattern shape defect inspection apparatus according to claim 6, wherein the shape parameter calculation processing unit uses, as the evaluation value, a differential value of the spectral reflectance of the substrate obtained by the spectral reflectance calculation processing unit.

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