JP3893825B2 - Defect observation method and apparatus for semiconductor wafer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor for automatically acquiring a high-magnification image of a defective portion in a microscope system such as an electron microscope after the presence of a defect generated in a semiconductor manufacturing process is confirmed by a semiconductor wafer defect inspection apparatus. Wafer The present invention relates to a defect observation method and apparatus therefor.
[0003]
[Prior art]
Conventionally, in the field of semiconductor development and manufacturing, a semiconductor wafer defect inspection device (hereinafter simply referred to as an inspection device) has been introduced to improve product quality and manufacturing yield, and is generated on products during the manufacturing process. Defects have been detected and inspection results have been fed back into the manufacturing process. The inspection apparatus mainly outputs the position and number of defects, but generally, information on the type of defect and the seriousness of the defect cannot be obtained. In order to obtain such information, it is necessary to observe each defect detected by the inspection apparatus in detail using an optical microscope or an electron microscope (hereinafter referred to as a review operation).
[0004]
Conventional review work is based on the defect position information provided by the inspection device, using an electron microscope with a coordinate function, etc., to acquire a high-magnification defect image that can be observed in detail by the operator. The defect type and severity were clarified by observing the defect, or the cause of the defect was estimated, but the inspection equipment often pointed out a huge number of defects, which required a lot of time and labor. .
[0005]
As an attempt to automate the review work, Japanese Patent Laid-Open No. 9-139406 discloses a technique for automating the acquisition of a high-resolution image for observing a defect portion. Here, based on the defect position information of the inspection device, the field of view of the electron microscope with coordinate function is set to the defect position, and the observation magnification is set to the maximum value that can allow the coordinate error between the inspection device and the electron microscope. And then processing the image to specify the presence of a defect as a singular point, and to image a defective part at an optimum magnification for observation based on the specified defect position. As a method for identifying singular points, according to the position of the defect, (1) if the position of the defect is a simple repeating pattern such as a semiconductor memory device, the image of the defective part is divided into an arbitrary size. (2) If the position of the defect is a random pattern such as a semiconductor logic circuit, an image of the corresponding part of the adjacent chip is captured. However, a method of specifying a defect position by pattern matching between an image of a defective part and an image of a corresponding part of an adjacent chip is shown.
[0006]
[Problems to be solved by the invention]
The conventional technique is aimed at automating the acquisition of a high-resolution image for observing a defect portion, but has a problem that an operator has to intervene at the stage of specifying the position of the defect. In other words, there is no way to know whether the position of the defect is on a simple repeating pattern such as a semiconductor memory device part or a random pattern such as a semiconductor logic circuit part. It is necessary to observe the image. In addition, it is stated that if the defect location is a simple repeating pattern such as a semiconductor memory device part, the image of the defective part may be divided into arbitrary sizes. Therefore, it is not always possible to specify the defect position. It is necessary to divide the pattern in consideration of the cycle of the simple repetition pattern, and again, the operator needs to measure the pattern pitch and input the measured value.
[0007]
An object of the present invention is to reliably collect a high-magnification image of a defective portion without involving an operator. Another object of the present invention is to display collected images so that the types and severities of defects can be clarified or the cause of defect occurrence can be easily estimated. Another object of the present invention is to automatically classify collected images.
[0008]
[Means for solving problems]
In order to achieve the above object, the present invention provides a defect observation apparatus for a semiconductor wafer, storage means for storing information on defects detected by inspecting a circuit pattern formed on the semiconductor wafer in advance with another inspection apparatus, and Imaging means for imaging the circuit pattern formed on the semiconductor wafer, image magnification setting means for setting the magnification of the image of the circuit pattern formed on the semiconductor wafer imaged by the imaging means, and imaging by the imaging means Image processing means for processing the circuit pattern image obtained in this manner to extract defects in the circuit pattern, display means for displaying the result processed by the image processing means on the screen, and control means, The control means controls the storage means, the imaging means, the image magnification setting means, the image processing means, and the display means, and uses the information on the defect of the circuit pattern stored in the storage means to include the defect. The captured by the first rate set by the magnification setting means by the imaging means, comparing the same magnification image taken by the first magnification by using the defect information stored in the storage means in the image processing unit Target The defect of the circuit pattern is extracted in comparison with the image, the position of the extracted defect in the coordinate system of the imaging means is calculated, and the image magnification setting means based on the information of the position of the defect in the calculated coordinate system of the imaging means The region including the extracted defect is set by a second magnification larger than the first magnification by the imaging means, and the image of the defect imaged at the second magnification is displayed together with information on the defect. It was configured to display on the means.
[0009]
In order to achieve the above object, according to the present invention, in the defect observation method for a semiconductor wafer, the defect information is detected using information on a defect detected by inspecting a circuit pattern formed on the semiconductor wafer with another inspection apparatus. A region including the image is imaged at a first magnification using a scanning electron microscope, and the same magnification as the first magnification at which the circuit pattern is imaged using the detected defect information is compared. Target The circuit pattern defect is extracted in comparison with the image, the position of the extracted defect in the scanning electron microscope coordinate system is calculated, and the defect is determined based on the calculated defect position information in the scanning electron microscope coordinate system. A region including the image of the defect is imaged with a scanning electron microscope at a second magnification larger than the first magnification, and an image of the defect imaged at the second magnification is displayed on the screen together with information on the defect.
[0010]
Furthermore, in order to achieve the above object, according to the present invention, in the defect observation method for a semiconductor wafer, the defect is detected using information on a defect detected by inspecting a circuit pattern formed on the semiconductor wafer with another inspection apparatus. Comparison area on the circuit pattern using the information of the defect detected by inspecting by the other magnification with the first magnification using the scanning electron microscope Target The part is imaged at the same magnification as the first magnification using a scanning electron microscope, and the image of the area including the defect obtained by imaging at the first magnification is compared. Target The circuit pattern defect is extracted in comparison with the image of the part, the position of the extracted defect in the coordinate system of the scanning electron microscope is calculated, and based on the information on the position of the defect in the coordinate system of the calculated scanning electron microscope A region including the defect is imaged with a scanning electron microscope at a second magnification larger than the first magnification, and an image of the defect imaged at the second magnification is displayed on the screen together with information on the defect. I made it.
[0011]
In order to achieve the above object, in the present invention, a scanning electron microscope is used to detect a region including the defect by using information on the defect detected by inspecting the circuit pattern formed on the semiconductor wafer with another inspection apparatus. An image including a defect obtained by imaging at a first magnification, creating an image including a defect and a comparison target image from an image obtained by imaging at the first magnification, and imaging at a first magnification. Compare images Target The circuit pattern defect is extracted in comparison with the image, the position of the extracted defect in the scanning electron microscope coordinate system is calculated, and the defect is determined based on the calculated defect position information in the scanning electron microscope coordinate system. A region including the image of the defect is imaged with a scanning electron microscope at a second magnification larger than the first magnification, and an image of the defect imaged at the second magnification is displayed on the screen together with information on the defect.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
FIG. 1 is a diagram showing an overall configuration of a high-magnification image automatic collection system for a defective portion of a semiconductor wafer according to the first embodiment of the present invention. 201 is a semiconductor wafer inspection apparatus (hereinafter simply referred to as an inspection apparatus), 202 is a microscope system, and includes a microscope section 202a that acquires an image of a sample, and a computer section 202b that controls the operation of the microscope system, performs image processing, and the like. Become. The microscope system 202 can receive the inspection result information 203 via the network 200. Inspection data from the inspection apparatus 201 and the microscope system 202 is stored in the storage device 204 via the network 200 and can be recalled as necessary. The defect image detected by the microscope system 202 is displayed on the display screen of the review monitor 205 of the microscope system 202 and is also stored in the storage device 204 via the network 200.
[0015]
Semiconductor to be inspected Wafer As shown in FIG. 2, a large number of chips 1a, which finally become the same product, are arranged in 1. The pattern layout inside the chip 1a includes a memory mat portion 1c in which memory cells are regularly arranged at the same pitch two-dimensionally and a peripheral circuit portion 1b as shown in the enlarged view of FIG. Usually this semiconductor Wafer In the pattern inspection of 1, a detection image on a certain chip (for example, chip 1 d) is stored and compared with a detection image on another chip (for example, chip 1 e) (hereinafter referred to as “chip comparison”), or This is implemented by storing a detected image in a certain memory cell (for example, memory cell 1f) and comparing it with a detected image in another cell (for example, cell 1g) (hereinafter referred to as “cell comparison”). The Alternatively, cell comparison and chip comparison may be performed in parallel (hereinafter referred to as “chip / cell mixed comparison”).
[0016]
In order to inspect a semiconductor wafer with the inspection apparatus 201, prior to the inspection, information on a comparison target, that is, information on a pattern repetition period (interval between memory cells or chip interval) and a direction of repetition, It is necessary to input information about whether the area is to be inspected by cell comparison to the inspection apparatus. In other words, the inspection apparatus has information indicating that the defect has been detected as a result of comparative inspection with respect to each defect portion. In the present invention, the inspection result information as shown in FIG. 1 is added to the inspection result information in addition to the defect information including the position of the defect, the feature amount of the defect, etc., and the information related to the comparison target as described above. Information is provided to the microscope system 202 as the result information 203.
[0017]
In the microscope system 202, a sequence is set up such that high-magnification images of defective portions are sequentially acquired based on the defect position information obtained from the inspection result information 203 corresponding to the set wafer, and displayed and stored. It is rare. At this time, the field of view at a high magnification is not sufficiently wide as compared with the accuracy of the position information of the defect obtained from the inspection result information 203. Therefore, only the position information of the defect obtained from the inspection result information 203 has a high magnification from the beginning. Even if it is attempted to acquire the image, it may happen that the image is out of view. Therefore, in the present invention, based on the defect position information obtained from the inspection result information 203, an image of the defective portion is first captured at a low magnification, and further compared based on the comparison object information obtained from the inspection result information 203. Images of the same part are taken at the same magnification. Then, the images are compared on the computer to identify where the position of the defect portion is in the field of view. If the position coordinate of the defect is found even in the coordinate system of the microscope system, it is moved to the center of the field of view (in the case of a scanning electron microscope, the electron beam scans a narrower region centered on the found defect coordinate. High-magnification images can be taken. Then, since the coordinates corresponding to the position coordinates on the comparison target part image corresponding to the position coordinates of the defect are also found, a high-magnification image of the comparison target part can be similarly captured. As described above, the process of acquiring the high-magnification defect portion image and the comparison target portion image starting from the low-magnification image acquisition is performed sequentially on the defects included in the inspection result information 203 using only the inspection result information 203. A sequence can be set up to perform and does not require operator intervention. In addition, the microscope system, which is already a common function, automatically detects the alignment mark and positions the wafer, auto-focus function at the imaging location, and detects the appropriate brightness image by auto gain control. Needless to say, an electronic microscope has a function of automatically adjusting stigma. According to the present invention, since the inspection result information of the inspection apparatus includes not only the positional information of each defect but also the comparison target information, in the microscope system, based on this information, the image of the defect portion and the correlation By detecting the images of the comparison target parts and comparing the images, it is possible to calculate the position of the defective part in the coordinate system of the microscope system. It is possible to collect high-magnification images.
[0018]
Using the collected high-magnification defect portion image and comparison portion image, the computer unit 202b performs image processing, and the result is attached to the image on the review monitor 205 as shown in FIG. It can be displayed together with information (for example, position information on the chip). Further, the result of image processing is stored in the storage device 204 via the network 200.
[0019]
Further, since the high-magnification images of the defect part and the comparison target part can be displayed on the review monitor 205 together with the data related to the positional relationship between them, the observer can identify the type of defect and the severity of the defect. There is also an advantage that judgment becomes easy.
[0020]
FIG. 3 is a diagram showing a schematic configuration of an optical semiconductor wafer defect inspection apparatus. In FIG. 3, it is an inspection object Wafer 1 is illuminated by a lighting lamp 3 through a half mirror, Wafer The reflected light from 100 is imaged on the image sensor 6 by the objective lens 5. As the image sensor, for example, a TDI (Time Delay & Integration) line sensor is suitable. And by stage 2, Wafer Can be detected in a direction perpendicular to the scanning of the image sensor, that is, in the X direction, to detect a two-dimensional image of the pattern to be inspected. The output signal S10 of the image sensor 6 is converted into a digital signal by the AD converter 8. The digital signal s1 is sent by the delay circuit 9 Wafer Is electrically delayed by the time required to move one chip or one cell. Wafer Is the time required to move by one chip, the original signal S1 and the output signal S2 of the delay circuit 9 correspond to adjacent chips, for example, the image signals 1e and 1d in FIG. This is equivalent to comparing 1d detection images. Wafer The same applies to the case where the time is one cell, and the original signal S1 and the output signal S2 of the delay circuit 9 correspond to the adjacent cells, for example, the image signals 1f and 1g in FIG. This is equivalent to comparing detected images of 1f and 1g. s1 and s2 are aligned in the alignment circuit 10 and then compared in the comparison circuit 11 to extract a defective portion. The extracted feature of the extracted defect is calculated in the feature extraction circuit 12 such as the size of the defect and the perimeter. FIG. 2 shows a configuration in which either cell comparison or chip comparison is performed, but a device configuration in which a plurality of delay circuits having different delay amounts are provided and inspections at various comparison intervals are performed in parallel is also possible.
[0021]
FIG. 4 is an example of inspection result information. In the present invention, as described above, in addition to the position of the defect and the feature amount, as comparison target information, it is distinguished whether the defect is detected by cell comparison or detected by chip comparison, and Taking FIG. 2 as an example, a chip interval d1 and a cell interval d2 are added.
[0022]
FIG. 5 is a diagram showing a schematic configuration of an electron beam type semiconductor wafer defect inspection apparatus. As shown in FIG. 5, the electron beam exiting the electron gun 31 passes through the condenser lens 32 and the objective lens 33, and is narrowed to a beam diameter of about the pixel size on the sample surface. When the electron beam is irradiated, the inspection object ( Wafer 1) From 100, electrons are generated. By detecting the electrons generated from the inspection object 100 in synchronization with the repeated scanning of the electron beam in the X direction by the scanning deflector 34 and the continuous movement of the inspection object (sample) 100 in the Y direction by the stage 132. A two-dimensional electron beam image of the inspection object is continuously obtained. Electrons generated from the sample are captured by the detector 25, amplified by the amplifier 26, and then converted into a digital signal S 1 by the AD converter 8. The subsequent processing is the same as that of the optical inspection apparatus of FIG.
[0023]
FIGS. 6 to 10 are diagrams showing the flow of processing in the microscope system 202 to identify the position of the defective portion using the inspection result information 203 and obtain a high-magnification image of the defective portion and a high-magnification image of the comparison target portion. It is.
[0024]
In FIG. 6, the image 1 including the defect portion based on the position information of the defect included in the inspection result information 203, and the image 2 including the comparison target portion based on the comparison target information are considered in consideration of the accuracy of the inspection apparatus defect coordinates. The position of the defect in the coordinate system of the microscope system is obtained by capturing the image at a low magnification that does not remove the defect from the image, importing it into the computer, and comparing the images 1 and 2 with the computer to detect the defect. Specify coordinates. And the image of a defective part is acquired with high magnification using the specified position coordinate.
[0025]
In FIG. 7, the computer compares the image 1 with the image 2 to detect the defect, thereby specifying the position coordinate of the defect in the coordinate system of the microscope system, and on the comparison target image captured at a low magnification. The corresponding position coordinates are calculated, and using the specified position coordinates, the image of the defective portion and the image of the comparison target portion are acquired at a high magnification.
[0026]
In FIG. 8, taking into account the accuracy of the inspection apparatus defect coordinates based on the defect position information included in the result information, the image is captured at a low magnification such that the defect portion does not deviate from the image, and is captured by the computer. 1 is coordinate-converted to create a comparison target image 1 and the image 1 is compared with the image 1 to detect a defect, thereby specifying the position coordinates of the defect in the coordinate system of the microscope system. As shown in the figure, since the images are created from the same image, two image defects appear when image comparison is performed, but since the method of coordinate conversion is known, the defect position is determined from any defect image. (In the example of this figure, since the image 1 is generated by shifting the image 1 upward, the coordinates of the defect in the coordinate system of the book image 1 are the lower side of the two appearing positions. Is the coordinates of the defect). And the image of a defective part is acquired with high magnification using the specified position coordinate.
[0027]
In FIG. 9, the computer compares the image 1 with the image 1 to detect the defect, thereby specifying the position coordinate of the defect in the coordinate system of the microscope system, and further, the specified position coordinate and the comparison target information From the above, the position coordinates of the comparison target part corresponding to the position of the defective part are also specified. Then, the image of the defective portion and the image of the comparison target portion are acquired at a high magnification using the specified position coordinates.
[0028]
FIG. 10 is a diagram showing a processing flow particularly when the microscope system is a scanning electron microscope. Until the position coordinates of the defect and the position coordinates of the comparison target part are specified, it is the same as in FIG. 9, but in the case of a scanning electron microscope, by limiting the scanning position of the electron beam to the vicinity of the specified coordinates, Detect high magnification images.
[0029]
Note that, as shown in FIGS. 9 and 10, a method of creating a comparison target image for specifying a defect position from the same image is not always usable. If the same image is shifted, the effective area of the image becomes narrower (for example, since the images are shifted up and down in FIGS. 9 and 10, the effective width in the vertical direction becomes narrower) or disappears. In the present invention, a method of creating a comparison target image for specifying a defect position from the same image if the interval with the comparison target included in the comparison target information is within a certain value (the same image method) is constant. If the value is exceeded, it is possible to automatically switch to take the system of FIGS. 6 and 7 (: separate image system) for capturing another image. This is an effect unique to the present invention in which the interval from the comparison target is known at the stage of receiving the inspection result information.
[0030]
In the present invention, the detection system of the microscope system is not limited to a normal optical microscope or a scanning electron microscope, but also to a laser scanning microscope, a confocal microscope, a fluorescence microscope, a focused ion beam device, and the like. Needless to say, diversion is possible.
[0031]
FIG. 11 is a diagram showing an overall configuration of the second embodiment of the present invention. 1 is different from the first embodiment shown in FIG. 1 in that a defect that should be acquired by the microscope system with the microscope system is not detected by passing the inspection result information of the inspection apparatus 201 to the microscope system 202 as it is. The point is to select. For selection, the distribution of defect positions is mainly used. For example, if a defect has occurred in the same part of all the chips, it is not necessary to review all of them, so only a few of them are flagged to instruct acquisition of a high-magnification image. For example, if there are characteristic defect distributions near the center and near the outer periphery of the wafer, several points are selected from each distribution. In addition, for example, if the distribution is such that the type of defect and the cause of occurrence have already been clarified from the history so far, it is not necessary to perform observation with a high-magnification image again. Do not attach a flag to instruct acquisition. According to this embodiment, since defects are narrowed down in advance, the image collection time in the microscope system can be shortened, and the image confirmation work time can be shortened.
[0032]
FIG. 12 is a diagram showing an overall configuration of the third embodiment of the present invention. In this example, the automatic defect classification computer 207 automatically classifies the defect images using the high-magnification images collected by the first or second embodiment and stored in the storage device 204, and the result Is displayed on the display of the computer 207 for automatic defect classification. In the present invention, since the high-magnification image of the defective portion and the comparison target image in a substantially positioned state have already been collected, basic processing in automatic defect classification such as separation of the defective portion and the background is ensured. Can be implemented. Then, for the “defect image without background” separated from the background, various feature quantities such as texture roughness, shape irregularity, brightness, circularity, thinness, etc. are calculated by image processing, The types of defects can be classified according to the feature amount. The result of classifying defects using this “background-less defect image” is displayed on the display of the automatic defect classification computer 207. Further, the result of classification of defects can be stored in the storage device 204 via the network 200 and recalled as necessary. In this embodiment, not only high-magnification image collection but also judgment work using images is automated, so that review work can be performed at higher speed.
[0033]
【The invention's effect】
According to the present invention, since the inspection result information of the inspection apparatus includes not only the positional information of each defect but also the comparison target information, in the microscope system, based on this information, the image of the defect portion and the correlation By detecting the images of the comparison target parts and comparing the images, it is possible to calculate the position of the defective part in the coordinate system of the microscope system. It is possible to collect high-magnification images.
[0034]
In addition, according to the present invention, the inspection result information of the inspection apparatus includes not only the position information of each defect but also the comparison target information, so in the microscope system, based on this information, the image of the defect portion, By detecting the images of the corresponding comparison target parts and comparing the images, it is possible to calculate the position of the defective part in the coordinate system of the microscope system. It is possible to collect a pair of a high-magnification image of a defective part and a high-magnification image of a corresponding comparison target part.
[0035]
In addition, according to the present invention, the defect coordinates for collecting high-magnification images are collected by the microscope system based on the position coordinates of the defect included in the inspection result information and the feature amount, and the inspection result information that has been narrowed down is Since it is provided to the system, the image collection time in the microscope system can be shortened, and the image confirmation work time can be shortened.
[0036]
In addition, according to the present invention, since the high-magnification image of the defective part and the high-magnification image of the comparison target part can be displayed on the screen together with the data related to the positional relationship between them, the type of defect for the observer Identification and determination of the seriousness of the defect becomes easy.
[0037]
In addition, when the high-magnification image of the defect portion and the high-magnification image of the comparison target portion collected according to the present invention are used in the automatic defect classification system, the comparison target image in a substantially positioned state has already been prepared. Therefore, basic processing in automatic defect classification, such as separation of the defective portion and the background, can be reliably performed.
[0038]
In addition, according to the present invention, in the automatic defect classification system, the comparison target image can also be used as an image showing the location of the defective portion, so that the automatic classification can be made more sophisticated than before.
[0039]
Furthermore, according to the present invention, it is possible to save labor and speed up review work, which has conventionally required a great deal of labor and time, and more easily obtain information on the type and severity of defects. There is an effect of being able to do it.
[Brief description of the drawings]
FIG. 1 is a front view showing an overall configuration of a first embodiment of a high-magnification image automatic collection system for defective portions of a semiconductor wafer according to the present invention.
FIG. 2 is a plan view of a semiconductor wafer showing the repeatability of a pattern on the semiconductor wafer.
FIG. 3 is a perspective view showing a schematic configuration of an optical semiconductor wafer defect inspection apparatus.
FIG. 4 is a diagram illustrating an example of inspection result information of the inspection apparatus.
FIG. 5 is a front view showing a schematic configuration of an electron beam type semiconductor wafer defect inspection apparatus;
FIG. 6 is a diagram showing a flow of processing for obtaining a high-magnification image of a defective portion in a microscope system.
FIG. 7 is a diagram illustrating a flow of processing for obtaining a high-magnification image of a defective portion and a comparison target portion in the microscope system.
FIG. 8 is a flowchart showing another processing flow for obtaining a high-magnification image of a defective portion in a microscope system;
FIG. 9 is a diagram illustrating another processing flow for obtaining a high-magnification image of a defective portion and a comparison target portion in the microscope system.
FIG. 10 is a diagram showing another processing flow for obtaining a high-magnification image of a defect portion and a comparison target portion in an electron microscope system;
FIG. 11 is a front view showing an overall configuration of a second embodiment of a high-magnification image automatic collection system for defective portions of a semiconductor wafer according to the present invention.
FIG. 12 is a front view showing an entire configuration of a third embodiment of a high-magnification image automatic collection system for a defective portion of a semiconductor wafer according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Wafer, 2 ... Stage, 3 ... Light source, 6 ... Linear image sensor, 8 ... A / D converter, 10 ... Delay circuit, 11 ... Positioning circuit, 12 ... Feature extraction circuit, 31 ... Electron gun, 32 ... Condenser lenses 32, 33 ... Objective lens, 34 ... Scanning deflector, 132 ... Stage, 25 ... Secondary electron detector, 26 ... Amplifier, 200 ... Network, 201 ... Semiconductor wafer inspection device, 202 ... Microscope system, 203 ... Inspection Result information, 204 ... storage device, 205 ... monitor for review, 206 ... computer for narrowing down the number of defects, 207 ... computer for automatic defect classification

Claims (15)

Storage means for storing information on defects detected by inspecting a circuit pattern formed on a semiconductor wafer in advance with another inspection apparatus, imaging means for imaging the circuit pattern formed on the semiconductor wafer, and the imaging Image magnification setting means for setting the magnification of the image of the circuit pattern formed on the semiconductor wafer to be imaged by the means, and processing the image of the circuit pattern obtained by imaging with the imaging means to process the circuit pattern Image processing means for extracting defects, display means for displaying the results processed by the image processing means on a screen, and control means, the control means comprising the storage means, the imaging means, and the image magnification setting means The image processing means and the display means are controlled to use the information on the defect of the circuit pattern stored in the storage means to set an area including the defect by the imaging means. Captured by the first rate set by the stage, using the information of the defect stored in the storage means is compared with the comparison image of the same magnification images captured by the first magnification by the image processing unit And extracting the defect of the circuit pattern, calculating the position of the extracted defect in the coordinate system of the imaging unit, and setting the image magnification setting unit based on the calculated position information of the defect in the coordinate system of the imaging unit The imaging unit picks up an area including the extracted defect set to a second magnification larger than the first magnification, and an image of the defect imaged at the second magnification together with information on the defect An apparatus for observing defects in a semiconductor wafer, characterized by displaying on said display means.   2. The defect observation apparatus for a semiconductor wafer according to claim 1, further comprising defect classification means for classifying the defects extracted by the image processing means based on a feature amount of an image of the defect. 3. The defect observation of a semiconductor wafer according to claim 2 , wherein the defect classification means classifies the defect based on a feature quantity of either the size of the defect or the peripheral length of the defect based on the image of the defect. apparatus.   2. The defect observation apparatus for a semiconductor wafer according to claim 1, wherein the defect information stored in the storage means includes information on a position of the defect and information on a comparison target used when detecting the defect.   The imaging means is a scanning electron microscope, and the magnification setting means irradiates and scans an electron beam focused on an area including a circuit pattern formed on the semiconductor wafer by the scanning electron microscope. 2. The defect observation apparatus for a semiconductor wafer according to claim 1, wherein the defect observation apparatus is set. The defect image of the second magnification displayed on the display means is obtained by comparing the defect image obtained by imaging at the second magnification by the imaging means with a comparison image having the same magnification as the second magnification. 2. The defect observation apparatus for a semiconductor wafer according to claim 1, wherein the defect observation apparatus is an extracted image. The comparison target image to be compared with the image obtained by imaging at the first magnification by the image processing means is formed on the semiconductor wafer using information on defects detected by inspection with the other inspection apparatus in advance. 2. The defect observation apparatus for a semiconductor wafer according to claim 1, wherein the circuit pattern is an image obtained by imaging the circuit pattern at the first magnification. 2. The defect observation apparatus for a semiconductor wafer according to claim 1, wherein the imaging means is an imaging means using an optical microscope.   2. The defect observation apparatus for a semiconductor wafer according to claim 1, wherein the image pickup means is an image acquisition means using a scanning electron microscope. Using the information of the defect detected by inspecting the circuit pattern formed on the semiconductor wafer with another inspection apparatus, the region including the defect is imaged at a first magnification using a scanning electron microscope, and the other Using the information on defects detected by inspection with an inspection apparatus, the comparison target portion on the circuit pattern is imaged at the same magnification as the first magnification using the scanning electron microscope, and is imaged at the first magnification. Comparing the image of the region including the defect obtained with the image of the comparison target portion to extract the defect of the circuit pattern, calculating the position of the extracted defect in the coordinate system of the scanning electron microscope,
Based on the information of the position of the defect in the calculated coordinate system of the scanning electron microscope, the region including the defect is imaged with the scanning electron microscope at a second magnification larger than the first magnification, and the first A defect observation method for a semiconductor wafer, wherein an image of the defect imaged at a magnification of 2 is displayed on a screen together with information on the defect. Using the information of the defect detected by inspecting the circuit pattern formed on the semiconductor wafer with another inspection apparatus, the region including the defect is imaged at a first magnification using a scanning electron microscope, and the other Using the information on defects detected by inspection with an inspection apparatus, the comparison target portion on the circuit pattern is imaged at the same magnification as the first magnification using the scanning electron microscope, and is imaged at the first magnification. Comparing the image of the region including the defect obtained with the image of the comparison target portion to extract the defect of the circuit pattern, calculating the position of the extracted defect in the coordinate system of the scanning electron microscope, Based on the calculated position information of the defect in the coordinate system of the scanning electron microscope, the region including the defect is imaged by the scanning electron microscope at a second magnification larger than the first magnification, and the circuit pattern the comparison pair of upper The part using the scanning electron microscope and imaged at the same magnification as the second magnification, and an image of the region at the second magnification including the second magnification defects imaged by obtaining comparison, as compared to a subject portion of the image to extract the defect of the circuit pattern, and wherein an image captured by a second magnification of the defect of the circuit pattern the extracted to be displayed on the screen together with information on the defect Defect observation method for semiconductor wafers. Using a defect information detected by inspecting a circuit pattern formed on a semiconductor wafer with another inspection apparatus, an area including the defect is imaged at a first magnification using a scanning electron microscope. An image including the defect and a comparison target image are created from an image obtained by imaging at a magnification of 1, and an image of a region including the defect obtained by imaging at the first magnification is compared with the comparison target image. Extracting the defect of the circuit pattern, calculating the position of the extracted defect in the coordinate system of the scanning electron microscope, and determining the defect based on the calculated position of the defect in the coordinate system of the scanning electron microscope The region including the image is captured with the scanning electron microscope at a second magnification larger than the first magnification, and the image of the defect imaged at the second magnification is displayed on the screen together with information on the defect. A semiconductor characterized by Defect observation method of Eha.   The defect observation method for a semiconductor wafer according to any one of claims 10 to 12, wherein the defects imaged and extracted at the second magnification are classified based on a feature amount of the image of the defect.   The defect extracted by imaging at the second magnification is classified based on a feature amount of either the size of the defect or the peripheral length of the defect based on the image of the defect. A defect observation method for a semiconductor wafer according to any one of 10 to 12.   11. The defect information detected by inspection with the other inspection apparatus includes information on a position of the defect and information on a circuit pattern to be compared used in detecting the defect. 12. A defect observation method for a semiconductor wafer according to any one of 12 above.

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