JP2001147114A - Inspection device of circuit pattern and inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reduction of an inspection time and detection of a falsely reported defect, by putting an inspection region within a scannable range of an electron beam, even if a substrate is tilted against the moving direction. SOLUTION: This device has such a constitution that the inspection region is divided corresponding to the scannable range of the electron beam and the electron beam is scanned, and that electron beam images in the divided inspection region are acquired continuously both before and after the division.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device, a liquid crystal,
The present invention relates to an inspection apparatus and an inspection method for a circuit pattern of a substrate having a fine circuit pattern typified by a photomask, a reticle, or the like for transferring a circuit pattern of a semiconductor device or liquid crystal.

[0002]

2. Description of the Related Art A case of inspecting a semiconductor wafer used in a manufacturing process of a semiconductor device will be described as an example.

A semiconductor device is manufactured by repeating a process of transferring a circuit pattern formed on a photomask on a semiconductor wafer by lithography and etching. 2. Description of the Related Art In a semiconductor device manufacturing process, defects such as defective circuit pattern formation and generation of foreign matter generated in lithography processing, etching processing, and other processing steps greatly affect the manufacturing yield of semiconductor devices. Therefore, it is necessary to detect the occurrence of a defect or abnormality early or in advance. For this reason, an inspection apparatus and an inspection method of a circuit pattern on a semiconductor wafer in a manufacturing process of a semiconductor device have been used and improved with the history of the semiconductor device.

[0004] As a device for inspecting defects existing in a circuit pattern on a semiconductor wafer, an optical-patterned wafer appearance inspection device is known. This is a defect inspection apparatus that irradiates a semiconductor wafer with white light to acquire an optical image, compares the same type of circuit pattern of a semiconductor device such as an LSI or a memory, and detects a difference portion as a defect. An outline of this inspection apparatus is described, for example, in the document "Monthly Semiconductor World", August 1995, pp. 96-99. In such an optical inspection apparatus, in inspecting a semiconductor wafer in a manufacturing process, a foreign substance such as a silicon oxide film through which light is transmitted, a defective circuit pattern having a photosensitive photoresist material on its surface, and an etching residue. Could not be detected. In addition, it was not possible to detect an etching residue or an opening defect of a minute conduction hole, which was lower than the resolution of the optical system. Further, a defect generated at the bottom of the step of the circuit pattern could not be detected because light did not reach or reflected light did not return.

[0005] As described above, with the miniaturization of circuit patterns, the complexity of circuit pattern shapes, and the diversification of materials, it has become difficult to detect defects using optical images. There has been proposed a method of comparing and inspecting a circuit pattern by using the method. In order to obtain a practical inspection time when comparing and inspecting a circuit pattern using an electron beam image, a conventionally known scanning electron microscope (hereinafter referred to as SE) is used.
M) (abbreviated as M), it is necessary to acquire an image at a very high speed. Then, it is necessary to ensure the resolution of the image acquired at high speed and the SN ratio of the image.

As an apparatus for comparing and inspecting patterns using an electron beam, J. Vac. Sci. Tech. B, Vol. 9, No. 6, pp. 3
005-3009 (1991), J. Vac. Sci. Tech. B, Vol. 1
0, No. 6, pp. 2804-2808 (1992), and Japanese Patent Laid-Open No. 5-2
No. 58703, US Pat. No. 5,502,306, irradiate a conductive substrate such as an X-ray mask with an electron beam having an electron beam current of 100 times or more (10 nA or more) of a normal SEM,
An inspection apparatus and an inspection method for detecting any of generated secondary electrons, reflected electrons, and transmitted electrons, and automatically detecting a defect by comparing and inspecting an image formed from the signal are disclosed.

As a method of acquiring an electron beam image at high speed, a method of continuously irradiating a substrate on the sample stage with an electron beam while continuously moving the sample stage is known. As a method of controlling the position of the electron beam necessary to obtain the position, a deflector controller is provided, the desired position of the moving stage of the substrate and the electron beam is calculated, and these data are transferred to the moving stage servo and the analog deflector of the electron beam. A control method for sending to the circuit is disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 5-258703.

[0008] The above-mentioned prior art is sufficient for a substrate holding error, particularly, a positional deviation between comparative images caused by an angular deviation between a moving direction of a substrate moving means and an arrangement direction of a circuit pattern on the substrate. However, there has been a problem that normal inspection cannot be performed if the displacement is large. That is, when scanning an electron beam to acquire an electron beam image while moving the substrate in one direction, it is assumed that a substrate such as a semiconductor wafer is held at a slight angle θ with respect to the moving direction. .

FIG. 2 is a plan view of the substrate for explaining the relationship between the moving direction of the wafer and electron beam scanning. As shown in FIG. 2, the wafer 1 is held at a slight angle θ with respect to the moving direction A indicated by the arrow. The scanning direction 4 of the electron beam is opposite to the moving direction A of the wafer 1. Therefore, the scannable range 2 of the electron beam is a rectangle parallel to the scanning direction 4.
Here, if the inspection area 3 is within the scannable area 2 of the electron beam, there is no unscannable area of the inspection area 3, so that the scannable area 2 of the electron beam and the inspection area 3 at each position in the scanning direction 4. The electron beam image of the inspection area 3 can be obtained by controlling the electron beam analog deflector in accordance with the positional relationship between. However, it can be easily understood that, when the inclination θ becomes large and the inspection area 3 deviates from the scannable range 2, an area where the electron beam cannot be scanned occurs.

As a countermeasure, it is conceivable to operate the wafer 1 so that the inspection area 3 is within the scannable range 2 of the electron beam when the wafer 1 is moved. For example, the movement of the wafer 1 is stopped at a position where the inspection area 3 is out of the scannable range 2, the wafer is moved in a direction perpendicular to the movement direction A of the wafer 1, and then the movement of the wafer 1 and the scanning of the electron beam are performed again. Do
This is repeated several times so that the inspection area 3 falls within the scannable range 2 of the electron beam. In this case, since the movement in the right angle direction is intermittent, the inspection time is reduced. Further, since the movement in the perpendicular direction, which is used in an auxiliary manner, is intermittent and minute movement, the movement operation becomes unstable, and as a result, the inspection image is distorted. there were. Since the actual pattern is not distorted in the inspection image, a false defect which is an erroneous defect is detected.

[0011]

As described above, in the prior art, when the substrate is inclined with respect to the moving direction, it is completely considered that the inspection area is out of the scannable range of the electron beam. Did not. As a result, there is a problem that the inspection time is reduced and a false defect is detected.

SUMMARY OF THE INVENTION It is an object of the present invention to prevent the inspection time from being reduced and the detection of false alarm defects by making the inspection area fall within the scannable range of the electron beam even when the substrate is inclined with respect to the moving direction. is there.

[0013]

In order to solve the above-mentioned problems, according to this embodiment, the inspection area is divided according to the scannable range of the electron beam, and the electron beam is scanned. An electron beam image is continuously acquired before and after division.

[0014] Further, an electron beam is scanned while moving the substrate having the circuit pattern in a direction between the first and second directions of the moving means to obtain an electron beam image of a striped region of the substrate. It is configured.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

In this embodiment, a semiconductor wafer used in a process of manufacturing a semiconductor device will be described as an example of a substrate to be inspected.

FIG. 3 is a longitudinal sectional view schematically showing the structure of the circuit pattern inspection apparatus and a block diagram schematically showing a control function. Circuit pattern inspection equipment is column 6
0 and control functions shown on the right side of FIG. The column 60 includes an electron source 50, a condenser lens 63, an objective lens 64, a deflection electrode 52, a sample holder 62 for holding a sample 61 such as a semiconductor wafer, a sample moving stage 56, a detector 54, and the like. Electron source 50, condenser lens 63,
The operation of the objective lens 64 and the like is controlled by the electron optical system controller 51, the operation of the deflection electrode 52 is controlled by the deflection control circuit 53, and the operation of the sample moving stage 56 is controlled by the stage control circuit 57.

A sample 61 is irradiated with a primary electron beam 71 generated from an electron source 50. In the process, condenser lens 6
An electron optical system constituted by coils and electrodes such as 3 and the objective lens 64 is controlled by the electron optical system controller 51 so that the primary electron beam 71 is focused at the position of the sample 61. Sample 6
1 is scanned by the deflection electrode 52 with the primary electron beam 71, and simultaneously with the scanning, the sample moving stage 56 is moved in a direction substantially perpendicular to the scanning to obtain a stripe image of the inspection area of the sample 61.

When the sample 61 is irradiated with the primary electron beam 71,
Secondary electrons 72 are generated from the sample 61. This secondary electron 7
2 is guided to the detector 54 by an electrode (not shown). The secondary electrons captured by the detector 54 are signalized by the detection circuit 55 and sent to the image processing device 58. The image processing device 58 temporarily stores the obtained detected image, compares the detected image with the storage image to be compared, and detects a difference portion as a defect. The host computer 59 provides a GUI for setting inspection conditions and the like, and manages individual control devices.

(Embodiment 1) A first embodiment of the present invention will be described.

FIG. 1 is a plan view of a wafer for explaining a method of setting an inspection area. Wafer 1 on which circuit pattern is formed
Is mounted on the inspection apparatus, as shown in FIG.
Has a slight inclination θ ′ with respect to the moving direction A of The moving direction A of the wafer 1 is a direction mainly operated among the degrees of freedom of operation of a wafer moving means (not shown) when forming an electron beam image required for inspection. Moving direction and wafer 1
Is determined based on the notch 1a formed in the wafer 1. In the case of a wafer having an orientation flat instead of the notch 1a, this is used as a reference.
FIG. 1 shows an example in which the wafer 1 is tilted. However, although rare, the circuit pattern may be formed to be tilted with respect to a normal direction. In this case, since the direction of the inspection area and the direction of the wafer determined by the position of the notch are inclined, the reference for electron beam scanning is adjusted to the inspection area consisting of an array of chips instead of the notch. In the present embodiment, for simplification of the description, the inspection area 3 has only one line.

In FIG. 1, when the inclination θ 'is small, as shown in FIG. 2, the inspection area 3 is within the scannable range 2 of the electron beam, and the inspection can be performed only by one scan.
However, when the inclination θ ′ is large, the inspection area 3 protrudes from the scannable range 2 and cannot be inspected by one scan.

Therefore, if the scanning is divided into two times and the inspection area 3 is included in each scannable range, the entire inspection area 3 can be inspected. At this time, between the scanning direction 41 and the scanning direction 43, the electron beam moves in the moving direction 42, but only the control in the scanning direction of the electron beam moves, and the primary electron beam 71 is moved by a blanking electrode (not shown). Blanking is performed and the sample 61 is not irradiated.

The scanning is divided into a plurality of scanning directions 41 and 43. The moving direction A and the speed of the wafer 1 are not changed, and are constant before and after the movement. Therefore, the inspection is performed continuously. Since the division of the inspection area is automatically performed by the apparatus, the user of the apparatus can execute the inspection and specify the inspection area without being aware of the division.

As shown in FIG. 1, the divided portions of the scannable range 2 partially overlap. If this part is scanned in duplicate, the amount of irradiated electrons will be larger than in other areas,
The obtained image is different from other areas. Therefore, it is necessary to control the primary electron beam 71 so as not to be irradiated repeatedly.

Regarding the relationship between the scannable range 2 and the scan width,
This will be described with reference to FIGS. 4 and 6 are partial plan views of a wafer taken out of the inspection area 3 in FIG. 1, and FIG. 5 is a time chart showing a temporal change of the detection data and valid data.

When the inclination of the wafer 1 is large, it is essential that the scanning width of the primary electron beam 71 has a margin. There are two ways to afford this.

First, as shown in FIG. 4, the primary electron beam 71 is scanned in the scanning direction 451 over the entire scannable range 21 to detect the secondary electrons 72. After the detection, the valid data at each scanning time is selected, and only the inspection area 3 is imaged. In this case, as shown in FIG.
Valid data is shorter than detected data. Therefore, the time of the portion of the detection data not used for the valid data is wasted time.

The second is, as shown in FIG.
The width of the scannable area 21 is given a margin more than the actual scanning width of the primary electron beam 71 in the scanning direction 451 along the width of
This is a method in which the starting point of scanning is adjusted to the inspection area 3. In this case, since the detection data and the valid data shown in FIG. 5 match, there is no dead time.

The scannable range 21 of the electron beam can be made larger, so that it can cope with a larger inclination of the wafer. However, according to the findings of the present inventors, a realistic value of the scannable range 21 is desirably 300 micrometers or less in order to achieve both high resolution of the inspection.

When the width of the inspection area 3 is large, the scanning of the primary electron beam 71 is divided into three or more times within the scannable range 21. As a result, it is possible to prevent a decrease in the sensitivity of detecting a defect due to image distortion.

If the entire scanning width exceeds this range,
The tilt is corrected by rotating the wafer 1 using the sample moving stage 56, the sample holder 62, or the like, or a fourth embodiment of the present invention to be described later is implemented.

The relationship between image acquisition by scanning of the primary electron beam 71 shown in FIG. 1 and image comparison will be described with reference to FIGS. FIG. 7 is a partial plan view of a wafer from which a portion of the inspection region in FIG. 1 is taken out. FIG. 8 is a time chart showing the time change of the comparison inspection using the detected data, the stored data and the data.

In FIG. 7, the inspection area 3 includes eight chips C1 to C8, and C1 to C4,
An example will be described in which inspection is performed in two scans by dividing into two regions C5 to C8.

The outline of the inspection flow is shown in FIG.
It consists of detecting, storing and comparing image data, and is continuously executed by pipeline processing. In the scanning direction 41,
The detection data from chip C1 to chip C4 is obtained. In the scan 43, detection data from the chip C5 to the chip C8 is obtained. In the comparative inspection, images stored in two memories are compared with each other, and a portion having a difference is detected as a defect. The detection data flows from storage data 1 stored in one memory to storage data 2 stored in another memory, and is subjected to a comparison test. For example, the storage data 1 of the chip C1 stored in the memory is stored as storage data 2 in another memory at the next time, and the chip C2 is stored as storage data 1 in the memory of the storage data 1. . At the next time, in the comparative inspection, data of the chip C1-2, which is the difference between the chip C1 and the chip C2, is created, and the defect is determined.

Since the detection data of the chip C5 is detected after the movement in the movement direction 42, the pipeline processing is stopped between the comparison between the chips C3 and C4 and the comparison between the chips C4 and C5.

In the region near the start and the end of the scanning of the electron beam, the amount of deflection of the electron beam is large, so that the distortion of the image data is large. Therefore, it is desirable to set the scanning division outside the area used for inspection.

If the number of chips in one stripe-shaped inspection area is even, the scribe area for cutting the chip between the two central chips is located exactly at the center of the inspection area. As in the example, the scanning of the electron beam may be divided there. As a result, the division section becomes a scribe area, so that distortion of an image in the inspection area can be prevented.

When the number of chips is an odd number, if the scanning of the electron beam is divided at the center of the inspection area, the scanning is divided within one chip, and the image before the division of the chip and the divided image after the division are divided. Even if an image of one chip is synthesized from the image, the image cannot be used for comparison with another chip because of image distortion.

In this case, the scanning is divided into two parts so that the division part for scanning comes to the scribe area. If this is not possible, the scan is divided into three parts so that the division part of the scan comes to the scribe area. As a result, it is possible to prevent a decrease in the sensitivity of detecting a defect due to image distortion.

(Embodiment 2) A second embodiment of the present invention will be described.

FIG. 9 is a plan view of a wafer showing a scanning method when the inspection area 3 has a plurality of stripes. As in the case of FIG. 1, the wafer 1 is tilted θ ′ with respect to the moving direction A.
have. The inspection area includes a plurality of stripe-shaped inspection areas 3a, 3b, 3c, 3d, and 3e. In the example of FIG.

When the inclination θ 'is small, as described with reference to FIG. 2, one stripe-shaped area can be inspected by one scan, so that the inspection is completed after only 2.5 reciprocations. In the example shown in FIG. 9, since the inclination θ ′ is large, each stripe-shaped region is divided into two in the scanning direction 41 and the scanning direction 43. During each scan, when the primary electron beam 71 moves in the movement direction 42 and the movement direction 44, the primary electron beam 71
Is blanked.

When the moving direction of the wafer 1 is the scanning direction 41, the scanning direction 4
At 3, the moving direction B is upward with respect to the paper surface.
When these wafer movement directions are reversed, the wafer 1 is moved by one stripe-shaped region in a direction perpendicular to the wafer movement direction. In one stripe-shaped area, the scanning is divided into a plurality of parts as in FIG. 1, but the inspection is performed continuously.

(Embodiment 3) A third embodiment of the present invention will be described.

FIG. 10 is a plan view of a wafer showing a scanning method when the inspection area is discontinuous. Although the inspection region 31 and the inspection region 32 are discontinuous, if the inclination θ ′ of the wafer 1 is small, the portion without the inspection region can be obtained by simply blanking the primary electron beam 71 as in FIG. Scannable. When the inclination θ 'of the wafer 1 is large, the movement shown in the movement direction 42 is required between the scanning direction 41 and the scanning direction 43, but the scanning can be performed as in the case of FIG.

(Embodiment 4) A fourth embodiment of the present invention will be described.

FIG. 11 is a plan view of a wafer showing a method for inspecting a plurality of stripe-like inspection regions. As shown in FIG. 11, when the inspection area 3a is greatly inclined with respect to the Y-axis direction which is one of the moving directions of the sample moving stage 56, the scanning as in the present embodiment is performed.

The sample moving stage 56 shown in FIG. 3 normally scans the electron beam while continuously moving the wafer 1 only in one of the X-axis direction and the Y-axis direction shown in FIG. In this case, the laser beam is moved in the direction of the other axis by the scanning width of the electron beam. However, in the case as shown in FIG. 11, the scanning direction 41 of the inspection area 3a is used.
Is set at an angle of 45 degrees with respect to the X axis or the Y axis as much as possible, and the movement of the wafer and the scanning of the electron beam described below are performed.

First, the control of the sample moving stage 56 is determined so that the angle between the moving direction A of the wafer 1 and the X or Y axis is 45 degrees. Next, the direction along the inspection area 3a is checked, and is matched with the moving direction A of the wafer 1. Then, while moving the wafer 1,
Scans the primary electron beam 71. When reaching the end of the inspection area 3a, the primary electron beam 71 is blanked, and the wafer 1 is moved at a right angle to the moving direction A of the wafer 1 in preparation for the next scanning of the inspection area 3b. Next, the primary electron beam 71 scans the region 3b in the scanning direction 43 while moving the wafer 1 in the moving direction B. This is called inspection area 3
For c, 3d, 3e, the scanning directions 45, 47,
49 is scanned with the primary electron beam 71.

The movement of the wafer on the sample moving stage 56 is
The accuracy of the moving speed is higher as the moving speed is constant and larger. This is because the control current of the motor that drives the sample moving stage 56 can be increased, and the number of control pulses per unit time can be increased. Therefore, an image with high positional accuracy can be obtained even when the electron beam is scanned during the movement.

The movement of the scanning width of the electron beam during the movement of the sample moving stage 56 at a constant speed is a movement of about 50 to 200 micrometers. Lower. Therefore, during this movement, electron beam scanning is not performed.

When the angle between the moving direction A of the wafer 1 and the X axis or the Y axis is set to 45 degrees, the case where the sample moving stage 56 is moved only in the X axis direction or the Y axis direction is as follows. Since the movement speed in each axis direction is the same,
Both speed accuracy and position accuracy can be secured. Therefore, it is desirable that the wafer moving direction A be as close to 45 degrees as possible.

The data flow in this embodiment will be described. FIG. 12 is a partial view of a plan view of a wafer from which a portion of the inspection region in FIG. 11 has been taken out, and FIG. 13 is a time chart showing temporal changes in comparative inspection using stored data and data.

For simplicity of explanation, 4 is added to the inspection area 3a.
And four chips in the inspection area 3b, for a total of eight chips,
In this example, the inspection is performed by dividing the inspection into two stripe scans in the scanning direction 41 and the scanning direction 43. FIG.
The circuit pattern inspection apparatus shown in (1) includes a memory having four or more surfaces for storing detection data. Or
It may have four or more memories for storing detection data. For the memory, there are various processes of writing detection data to each surface, reading out to a displacement detection step, and reading out to a comparison inspection step.

In FIG. 12, the comparison between the chips C1 and C2, the comparison between the chips C2 and C3, the comparison between the chips C3 and C4, and the comparison between the chips C5 and C6 and the comparison between the chips C6 and C6 are conventionally performed. And chip C7
, And a comparison between the chip C7 and the chip C8. As described above, there is no comparison between the chip C4 and the chip C5, and the comparison inspection step becomes discontinuous. In the comparative inspection, the same chip is compared twice with the preceding and succeeding chips to determine the presence or absence of a defect. However, the first chip C1 and the chip C5, and the end chips C4 and C8 are determined. I don't know if it's flawed.

In this embodiment, these defects can be detected by comparing the chips C4 and C5 on the way.

In FIG. 13, detection data of chips C1 and C5 is stored on the first surface of the memory, detection data of chips C2 and C6 is stored on the second surface, and detection data of chips C2 and C6 is stored on the third surface. , The detection data of the chip C3 and the chip C7 are stored, and the detection data of the chip C4 and the chip C8 are stored on the fourth surface. These writings are indicated by oblique lines. At the next time, the detection data written on each surface is read by a selector (not shown).

In the displacement detection step, the displacement between adjacent chips to be compared is detected before comparison, corrected if necessary, and the comparison inspection step is executed at the next time.

Here, looking at one chip,
In FIG. 12, the detection data obtained by scanning in the scanning direction 41 has a signal obtained from the bottom to the top of the page, and the detection data obtained by scanning in the scanning direction 43 has a signal obtained from the top to the bottom of the page. Since the images are turned upside down, the images are turned upside down.
4 and chip C5 cannot be directly compared.

Therefore, the difference between the upper and lower sides of the image depending on the acquisition direction of the electron beam image is corrected. The correction may be performed by changing the order of the signals based on the scanning direction, the direction of the sample moving stage, the chip ID, and the like when writing or reading the data into or from the memory. Since the memory has four storage surfaces, this operation can be easily performed. In this manner, a comparative inspection can be performed on a plurality of stripe-shaped inspection regions as if they were continuous inspection regions.

The detection data shown in FIG.
In the case of five, five planes or five memories are required. Since the storage surface of the memory or the number of memories is determined according to the number of detected data, the circuit pattern inspection apparatus shown in FIG. 3 has a memory having four or more surfaces for storing detected data, or Four or more memories for storing detection data are provided.

When the substrate is a process wafer of a semiconductor integrated circuit and the semiconductor integrated circuits are arranged in a lattice pattern on the substrate, the end of the inspection area is located at the position of the scribe area of the semiconductor integrated circuit as a chip. To That is,
The end of the scannable area of the electron beam is positioned closer to the scribe area than the end of the chip so that the image of the area of the chip does not have distortion. As a result, it is possible to prevent a decrease in the sensitivity of detecting a defect due to image distortion.

As described above, according to the present embodiment, the following effects can be obtained.

1. By dividing the stripe-shaped inspection area into two or more parts so that each inspection area falls within the scan range of the electron beam, the electron beam image of the divided inspection area is processed as an equivalent continuous image. In addition, it is possible to inspect a sample having a long inspection area while improving the inspection resolution.
Here, since the apparatus automatically divides the inspection area, the user of the apparatus can specify the inspection area without being aware of the division. 2. The scanning region of the electron beam is divided so that the division unit is located in the chip, that is, the scribe region of the semiconductor integrated circuit device. As a result, it is possible to prevent a decrease in the sensitivity of detecting a defect due to image distortion.

3. In an inspection using an electron beam, the influence of the electron beam irradiation is slight, and it is important to uniformly irradiate the inspection area with the electron beam. By providing at least four or more electron beam image storage means, it is possible to correct a difference in inspection direction, and to eliminate the occurrence of a non-inspection area. Further, since it is possible to detect a displacement between images, it is possible to improve the detection sensitivity by correcting the displacement.

4. By setting the scanable range of the electron beam within 300 micrometers, the scan range can be reduced and the influence of noise due to the analog deflector can be suppressed. Thereby, the resolution of the image is increased and the detection sensitivity is improved.

5. If the substrate is a process wafer of a semiconductor integrated circuit device, the comparison of electron beam images is made in a corresponding region between chips, and a defect of the semiconductor integrated circuit device can be detected. Therefore, defects can be found during the device manufacturing process, and the device manufacturing process itself can be evaluated. For example, it is effective in optimizing manufacturing conditions. Further, if the defect itself is fatal to the chip, it is effective for shortening the process, such as omitting subsequent inspection of the chip.

6. When the substrate is a process wafer of a semiconductor integrated circuit and the semiconductor integrated circuits are arranged in a lattice on the substrate, the end of the inspection region is set to the position of the scribe region of the semiconductor integrated circuit. As a result, it is possible to prevent a decrease in the sensitivity of detecting a defect due to image distortion.

[0070]

As described above, according to the present invention, even if the substrate is inclined with respect to the moving direction, the inspection area is located within the scannable range of the electron beam, thereby reducing the inspection time and false alarm. An effect that detection of a defect can be prevented can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a wafer for explaining a method of setting an inspection area.

FIG. 2 is a plan view of a substrate illustrating a relationship between a moving direction of a wafer and electron beam scanning.

FIG. 3 is a vertical cross-sectional view schematically showing the configuration of a circuit pattern inspection apparatus, and a block diagram schematically showing a control function.

FIG. 4 is a partial plan view of a wafer from which a portion of an inspection region in FIG. 1 is taken out.

FIG. 5 is a time chart showing temporal changes of detection data and valid data.

FIG. 6 is a partial plan view of a wafer from which a portion of an inspection region in FIG. 1 is taken out.

FIG. 7 is a partial plan view of a wafer from which a portion of an inspection region in FIG. 1 is taken out.

FIG. 8 is a time chart showing a time change of a comparison inspection using detection data, storage data, and data.

FIG. 9 is a plan view of a wafer showing a scanning method when the inspection area has a plurality of stripes.

FIG. 10 is a plan view of a wafer showing a scanning method when an inspection area is discontinuous.

FIG. 11 is a plan view of a wafer showing a method for inspecting a plurality of stripe-shaped inspection regions.

FIG. 12 is a partial plan view of a wafer from which a portion of an inspection region in FIG. 11 is taken out.

FIG. 13 is a time chart showing a temporal change in a comparative inspection using stored data and data.

[Explanation of symbols]

1 ... wafer, 2,21 ... scannable range, 3,31,32
... inspection area.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H01J 37/22 502 H01L 21/66 J 5C033 H01L 21/66 G06F 15/62 405A (72) Inventor Yasuhiro Gunji Hitachinaka, Ibaraki 882, Ichige, Ichimo F-term in Hitachi Measuring Instruments Group Co., Ltd. (reference) BA02 CA39 DB05 DB18 DB30 DH24 DH33 DH50 DJ15 DJ18 DJ21 5B057 AA03 BA01 BA19 BA21 CH05 DA03 DC32 5C001 AA03 CC04 5C033 FF03

Claims (9)

[Claims] 1. A holding means for holding a substrate having a circuit pattern,
Moving means for operating the holding means having two degrees of freedom in directions substantially perpendicular to each other, means for scanning an electron beam to form an electron beam image of the substrate, and first and second regions of the substrate. In a circuit pattern inspection apparatus comprising: means for storing an electron beam image; and means for comparing the electron beam images of the first and second regions to detect a defect, wherein the moving means is provided in the two directions substantially orthogonal to each other. Is operated in any one of the directions, the means for forming the electron beam image scans the stripe-shaped region of the substrate divided according to the scannable range of the electron beam with the electron beam, An inspection apparatus for a circuit pattern, wherein an electron beam image of the striped area scanned by an electron beam is continuously obtained before and after the division. 2. The circuit pattern according to claim 1, wherein the stripe-shaped region of the substrate is divided in one of the two substantially orthogonal directions. Inspection equipment. 3. The circuit pattern inspection apparatus according to claim 1, wherein the means for storing the electron beam image includes at least four or more areas for storing the electron beam image. 4. The circuit pattern inspection apparatus according to claim 1, wherein said means for storing said electron beam image comprises a device for storing at least four or more electron beam images. 5. The circuit pattern inspection apparatus according to claim 1, wherein the scanable range of the electron beam is within 300 micrometers. 6. The semiconductor device according to claim 1, wherein the substrate is a semiconductor wafer used for manufacturing a semiconductor integrated circuit, and a divided region of the stripe region is arranged in a scribe region between the semiconductor integrated circuits. A circuit pattern inspection apparatus, characterized in that: 7. A holding means for holding a substrate having a circuit pattern,
A moving unit having a degree of freedom of operation in two directions substantially orthogonal to each other and operating the holding unit, and scanning a plurality of stripe-shaped inspection regions set on the substrate with an electron beam to form an electron beam image of the inspection region. Means for storing electron beam images of the first and second regions included in the plurality of stripe-shaped inspection regions, and detecting defects by comparing the electron beam images of the first and second regions. The moving means aligns a longitudinal direction of the plurality of striped inspection areas in a direction substantially 45 degrees with respect to two substantially orthogonal directions of the moving means. And a circuit pattern inspection apparatus which is operated in a direction substantially 45 degrees with respect to the two directions substantially orthogonal to each other. 8. A holding means for holding a substrate having a circuit pattern,
A first moving unit that moves in one direction, a second moving unit that moves in a direction substantially perpendicular to the moving direction of the first moving unit, and the holding unit includes the first moving unit and the second moving unit. Means for scanning a plurality of stripe-shaped inspection areas set on the substrate with an electron beam while forming at least one of the moving means to form an electron beam image of the inspection area; and the plurality of stripe-shaped inspection areas. A circuit pattern inspection apparatus comprising: means for storing electron beam images of the first and second regions included in; and means for comparing the electron beam images of the first and second regions to detect a defect. Rotating means for rotating the holding means in a substantially horizontal direction, the rotating means moving the longitudinal direction of the plurality of striped inspection areas of the substrate with the moving direction of the first moving means and the second moving direction. Of the moving direction of the moving means The first moving means and the second moving means align the holding means with the moving direction of the first moving means. An apparatus for inspecting a circuit pattern, wherein the apparatus is moved in a direction between a moving direction and a moving direction of the second moving means and substantially 45 degrees with respect to a moving direction of the second moving means. 9. A method according to claim 1, wherein the substrate having the circuit pattern is moved in one of the first and second directions or in a direction between the first and second directions, and the first and second stripes of the substrate are scanned by an electron beam. In the circuit pattern inspection method of acquiring an electron beam image of the area and comparing the electron beam images of the first and second areas to detect a defect, the first and second areas are A method for inspecting a circuit pattern, comprising dividing an image according to a scannable range and continuously acquiring an electron beam image before and after the division.