KR19990023403A - Method and Apparatus for Inspection of Micro Repeat Pattern - Google Patents

Abstract

The present invention relates to a method and an apparatus for inspecting a foreign object in an ultra-small repeating pattern. In order to provide a method and an apparatus for inspecting the size and shape of a foreign object, A step of detecting scattered light of inspection light scattered on a surface of at least an object to be inspected by a scattered light detector; a step of detecting a scattered light of a scattered light A step of capturing an image of a foreign object whose coordinate position is determined under bright field illumination by the irradiating means at a coordinate position corresponding to the coordinate position in the scattered light detection step in accordance with the detection; According to the image of the foreign object extracted according to the captured image, the size, shape, color, and attribute of the foreign object It was also a configuration including a step of determining one to foreign matter.

This makes it possible to specify the size, shape, color, and property of the foreign object so that inspection and review of the foreign object can be performed accurately and quickly, fatal flaw can be determined, and the utilization efficiency of the foreign object inspection method can be improved Effect is obtained.

Description

Method and Apparatus for Inspection of Micro Repeat Pattern

More particularly, the present invention relates to a method and an apparatus for inspecting minute foreign matters on the surface of an object to be inspected such as a micro-repeated pattern formed on a semiconductor wafer.

2. Description of the Related Art In recent years, the integration of a semiconductor integrated circuit (hereinafter referred to as " IC ") and the miniaturization of circuit patterns have progressed, and circuit patterns formed thereon have become 1 m or less in width. In order to manufacture an IC having high productivity, a foreign matter attached to the surface of a wafer is detected, and its size, shape, characteristics and properties are inspected to quantitatively grasp the cleanliness of apparatuses and processes for producing various semiconductors, It is necessary to accurately manage it. Therefore, conventionally, foreign matter on the wafer is inspected by a method and apparatus for inspecting foreign objects attached to the wafer as an operation of a factory IC manufacturing process, and the manufacturing process is accurately managed.

Conventionally, a foreign substance inspection apparatus on a wafer can roughly be divided into two types. The first is a patterned wafer inspection apparatus of an image comparison system (hereinafter, referred to as an inspection inspection station) that performs comparison between an image under bright field of illumination and a reference pattern stored in advance. The second type is to detect the scattered light under the obscuration of the illumination in the oblique direction and recognize the presence or absence of defects or foreign objects to determine the coordinate position and the number based on the coordinates obtained upon detection of the scattered light (hereinafter, Of the patterned wafer inspection apparatus.

An example of a foreign substance inspection apparatus on a wafer is described in Nikkei Micro-devices, March, 1997, pp. 97-116, published by Nikkei Corporation.

The above-mentioned appearance inspecting apparatus has an advantage of high inspection accuracy, but has a disadvantage of low throughput and high cost. Since the image or appearance data can be obtained by the visual inspection apparatus, it is possible to perform review (that is, visual confirmation or inspection by an image). However, in the visual inspection apparatus, there are too many unnecessary information to be reviewed, such as a minute defect, compared to the number of wafers to be inspected. Therefore, there is a problem that the possibility of obtaining a fatal defect is very low and the review efficiency is lowered. .

On the other hand, the inspection apparatus has a problem that the inspection accuracy is lower than that of the appearance inspection apparatus, but it has an advantage that the throughput is higher and the cost is lower than that of the appearance inspection apparatus. Since the data obtained by the inspection apparatus includes the coordinate position of the defect on the surface of the wafer and the intensity of scattered light, the size of the defect (i.e., the diameter of the particle) and the shape (approximately S (small) , And L (large)). Therefore, in order to obtain more detailed information on this, it is necessary to use an inspection apparatus of an analytical system such as the above-mentioned visual inspection apparatus or other kinds of inspection apparatuses such as an SEM (Scanning Electron Microscope) .

It is an object of the present invention to provide a foreign matter inspection method and apparatus capable of efficiently acquiring a fatal defect and checking its size and shape.

1 is a perspective view showing a foreign substance inspection apparatus according to an embodiment of the present invention,

FIG. 2 is a view illustrating a foreign object inspection method that is performed using a foreign object inspection apparatus according to an embodiment of the present invention;

Fig. 3 (a) is a view showing an image in a state in which a foreign object is attached, Fig. 3 (b) is an image in a state in which no foreign object is attached Fig. 3 (c) is a view showing extracted foreign objects, Fig. 3 (d) is a view showing a state in which an image is extracted,

Fig. 4 is an explanatory view showing the sorting action. Fig. 4 (a) is a view showing an action of specifying the vertical and horizontal sizes of a foreign object, and Fig. 4 (b) Fig. 4 (c) is a view showing an action of specifying a circular foreign object, Fig. 4 (d) is a view showing an action of specifying an elongated object,

5 (a) and 5 (b) illustrate various analysis data. FIG. 5 (a) is a view showing the size of a foreign object, Fig. 5 (d) is a bar graph shown by the shape of a foreign object, Fig. 5 (e) is a time series graph of inspection results,

FIG. 6 is a perspective view showing a first modified example of the apparatus for inspecting a foreign body according to the present invention,

FIG. 7 is a view illustrating a foreign object inspection method that is performed using the foreign object inspection apparatus according to the first modification. FIG.

FIG. 8 is a view showing the operation of the foreign body inspection apparatus according to the first modification, wherein FIG. 8 (a) is a view showing the grouping operation, FIG. 8 (b)

FIG. 9 is a perspective view showing a second modified example of the foreign substance inspection apparatus according to the present invention,

FIG. 10 is a perspective view showing a third modification of the foreign substance inspection apparatus according to the present invention,

11 is a view showing a foreign matter inspection method to be processed using a foreign matter inspection apparatus according to another embodiment of the present invention,

12 is a view for explaining recognition of a single foreign object when an image is divided into three in the foreign substance inspection method according to another embodiment of the present invention,

13 is a view for explaining recognition of a single foreign object when an image is divided into two in the foreign substance inspection method according to another embodiment of the present invention,

FIG. 14 is a view showing a wafer in which fatal defects and defective chips are displayed in a foreign substance inspection method according to another embodiment of the present invention, FIG.

Fig. 15 is a view for explaining recognition of a single foreign object in the first modification of the another embodiment of the present invention. Figs. 15 (a) to 15 (c) A saturation color distribution chart,

16 is a view for explaining recognition of a single foreign object when an image is divided into two in the first modification of the other embodiment of the present invention,

17 is a view for explaining the recognition of a single foreign object in the second modification of the other embodiment of the present invention,

FIG. 18 is a view for explaining recognition of a single foreign object in the third modification of the another embodiment of the present invention. FIG.

In order to attain the above object, according to the present invention, there is provided a method for inspecting a microscopic repeated pattern formed on a surface of an inspected object, comprising the steps of: irradiating inspection light onto a surface of an inspected object on which an ultra- A step of detecting the scattered light of the inspection light scattered on the surface of the inspection object with the scattered light detector, a step of determining the coordinate position of the foreign object on the surface of the inspection object in accordance with the detection of the scattered light in the step, A step of picking up an image of the foreign object whose coordinate position has been determined in the step under illumination of bright field by the irradiating means at a coordinate position corresponding to the coordinate position and a step of picking up an image of the foreign object extracted according to the image picked up in the step , A step of determining at least one of the size, shape, color, and properties of the foreign object as foreign matters The.

In order to attain the above object, according to the present invention, there is provided an apparatus for inspecting a micropattern of repeated patterns formed on a surface of an object to be inspected, comprising: a light irradiation device for irradiating inspection light onto a surface of the object, A scattered light detector for detecting scattered light of the inspection light scattered on the surface of the object to be inspected, means for determining a coordinate position of the foreign object on the surface of the inspected object in accordance with the detection of the scattered light, An image pick-up means for picking up an image of the foreign object judged by the coordinate position under bright field illumination by the irradiating means at a coordinate position corresponding to the coordinate position judged by the coordinate position judging means In accordance with the image of the foreign object extracted in accordance with the imaging of the image obtained by the imaging means, It means for determining at least one of a size, shape, color and properties of the particle as foreign matter.

Further, according to the present invention, the foreign body inspection apparatus is characterized in that the foreign substance inspection apparatus is provided with an image of the micropattern under bright field illumination at a different coordinate position on the surface of the inspected object, which is different from the coordinate position determined by the determination means, And means for obtaining an image subjected to arithmetic processing between the inspection object image and the reference image, wherein the determination means determines whether or not the arithmetic processing obtained by the means for obtaining the arithmetic processed image The presence or absence of a defect is determined at a coordinate position determined on the predetermined object to be inspected according to the image.

In order to attain the above object, according to the present invention, there is provided an apparatus for inspecting a micropattern of repeated patterns formed on a surface of an object to be inspected, comprising: a light irradiation device for irradiating inspection light onto a surface of the object, A scattered light detector for detecting scattered light of the light scattered on the surface of the object to be inspected, means for obtaining first information related to a foreign object attached on the surface of the inspected object obtained by the scattered light detector by the scattered light detector, An illuminating means for illuminating the surface of the inspected object having the repeated pattern formed thereon, a means for capturing an image of the foreign object under bright field illumination by the illuminating means, a means for capturing an image of the foreign object under the bright- Means for obtaining second information related to the foreign object in accordance with the image of the foreign object obtained in accordance with the imaging, And means for displaying the first information and the second information on the display screen.

In order to achieve the above object, according to the present invention, there is provided a method for inspecting a micro-pattern repeated pattern formed on a surface of an inspected object, comprising the steps of: Capturing an image of an ultra-small pattern under bright field illumination at a different coordinate position corresponding to the coordinate position and different from the coordinate position on the surface of the inspected object to obtain a reference image; A step of obtaining an image subjected to arithmetic processing between the inspected object image and the reference image and a step of determining the presence or absence of a foreign object at a predetermined coordinate position on the inspected object according to the condition of the computed image.

These and other objects and features of the present invention will become apparent from the following detailed description of the embodiments to be considered in conjunction with the accompanying drawings.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. In the following description, a foreign object refers to defects in the shape of a pattern on the surface of an object to be inspected, defects in pattern defects, contamination, residues, scratches, It is included.

FIG. 1 is a perspective view showing a foreign substance inspection apparatus according to an embodiment of the present invention, FIG. 2 is a view showing the method, and FIG. 3 is an explanatory view for explaining the operation thereof.

In the present embodiment, the particle inspection apparatus 10 according to the present invention detects scattered light in a wafer as an object under the darkness due to illumination in an oblique direction, and when scattered light is detected, , A coordinate position, and a number of points. The inspection object, that is, the wafer 1 is in the process of manufacturing an IC such as a DRAM for each chip portion 4 on the first main surface 2, and the chip portion 4 is formed by cutting a part of the wafer 1, Are regularly arranged in the vertical and horizontal directions with respect to the frame 3. A defect occurs when the foreign matter 5 is attached to the first main surface 2 of the wafer 1. [ Therefore, the foreign object 5 attached to the first main surface 2 of the wafer 1 is detected by the foreign object inspection apparatus 10, and the position, number, size, shape, color, Understand the degree of cleanliness in manufacturing equipment and processes and accurately manage the manufacturing process.

The foreign object inspection apparatus 10 includes an XY table 12 for scanning the wafer 1 as an object to be inspected, a? Table 13 for rotating the wafer 1 in the? Direction, a focusing mechanism (not shown) And a controller (14) for controlling the stage (11). In order to inspect the entire surface of the wafer 1, X-Y scanning of the wafer 1 is performed by the stage device 11. [ During this scanning, the coordinate positional information on the wafer 1 as the inspected object in the controller 14 is input to the foreign substance judging device to be described later.

The inspection light irradiating device 20 is provided above the stage device 11 in the oblique direction. The inspection light irradiation device 20 comprises a laser irradiation device 22 for irradiating the wafer 1 with a laser beam 21 and a condenser lens 23 for condensing the laser beam 21, The wafer 1 is irradiated with the condensed laser beam 21 to illuminate the wafer 1 in the oblique direction.

The scattered light detection device 30 is provided immediately above the stage device 11. [ The scattered light detection device 30 includes an objective lens 32 for condensing the scattered light 31 scattered on the surface of the wafer 1 in accordance with the irradiation of the laser light 21 in the oblique direction, And a scattered light detector 34 for detecting scattered light in accordance with an image formed on the light receiving surface. That is, the scattered light detection device 30 is configured to detect the scattered light 31 under the dark background illumination. In this embodiment, the scattered light detector 34 is constituted by a line sensor in which a photoelectric conversion type solid-state image sensor such as a CCD (Charge Coupled Device) is arranged in a line along the Y direction orthogonal to the moving direction of the stage .

The scattered light detector 34 is connected to the foreign substance judging device 35. The foreign substance judging device 35 judges the presence or absence of a foreign object on the wafer 1 according to the timing of detecting the scattered light from the scattered light detector 34, And the coordinate positions of the foreign object are specified by combining the data for determining the data. The scattered light detector 34 is configured to transmit the intensity of the scattered light to the foreign substance judging device 35. In the present embodiment, a vertical spot illumination device 40 is provided directly above the stage device 11. [ The night illumination device 40 includes a white light 41 for irradiating the bright light to the wafer 1, a half mirror 43 for vertically reflecting the white light 41, and a half mirror 43 for forming the white light 41 in a spot shape. And the white light 41 is irradiated perpendicularly to the wafer 1 as the inspected object held by the stage device 11 and illuminated.

An image pickup device 45 is provided at a position opposite to the drop lighting device 40. That is, the image pickup device 45 is configured such that a photoelectric conversion type solid-state image sensor such as a CCD (Charge Coupled Device) or the like is mounted on the transmission side of the half mirror 43 in a direction perpendicular to the moving direction of the stage on the optical axis of the drop- And a line sensor arranged in a line along the direction. That is, the imaging device 45 is adapted to capture an image of reflected light under bright field illumination.

The comparison section 47 is connected to the image processing section 46 of the image pickup device 45 and the verification section 48 is connected to the output terminal of the comparison section 47. The other input terminal of the comparison section 47, The foreign object judging device 35 is connected to the other input end of the foreign object judging device 48. The foreign object judging device 35 includes a host computer 36 for controlling the foreign object inspecting device 10, ) To transmit the determination result.

Next, a method of inspecting a foreign object by the above-mentioned foreign object inspection apparatus as an embodiment of the present invention will be described with reference to Fig.

The laser light 21 as the inspection light is irradiated onto the wafer 1 at a low inclination angle by the inspection light irradiation device 20 so that the laser light 21 is irradiated onto the first main surface 2 of the wafer 1, The scattered light 31 is generated under the dark background illumination in the foreign matter 5 and the circuit pattern The scattered light is condensed by the objective lens 32 and is image-formed on the scattered-light detector 34 via the relay lens 33.

At this time, scattered light from the circuit pattern 31 (not shown) is blocked by the light shielding element (not shown) made of a spatial filter or an analyzer provided on the Fourier transform surface of the pattern surface of the wafer 1 Is shielded from light. On the other hand, since the scattered light 31 from the foreign object 5 is irregular, it is imaged on the scattered light detector 34 passing through the spatial filter or the analyzer. Therefore, only foreign objects can be detected.

The detection signal detected by the scattered light detector 34 by the scattered light 31 from the foreign object 5 under the dark background illumination is input to the foreign substance judging device 35. [ The foreign substance judging device 35 judges the presence or absence of the foreign object 5 in accordance with the detection signal and combines the judgment data with the data of the coordinate position from the controller 14 of the stage device 11, 5). The coordinate positions thus specified are detected by, for example, a host computer 36 which comprehensively executes the foreign object inspection apparatus 10 in the foreign object judging device 35 and a comparator 47 electrically connected to the image capturing device 45, And is output to the verification unit 48.

When the coordinate position of the foreign object 5 transmitted from the foreign object judging device 35 comes to the imaging position of the imaging device 45, that is, the spot from the back lighting device 40, Lt; RTI ID = 0.0 > brightfield < / RTI > illumination. Since the foreign object 5 is attached to the coordinate position according to the action of the foreign object judging device 35, the foreign object 5 appears on the image as shown in Fig. 3 (a). That is, an image of the inspected object is obtained.

Thereafter, the coordinate position shifted by the distance of the one-chip portion 4 from the coordinate position of the foreign object 5 transmitted from the foreign substance judging device 35, that is, the coordinate position where the foreign substance 5 is attached, When the coordinates corresponding to the coordinates of the foreign object 5 in the image pickup device 45 become the image pickup position of the image pickup device 45, the comparator 47 receives the image signal from the image pickup device 45 under bright illumination . The foreign object 5 does not adhere to the coordinate position thereof in accordance with the action of the foreign object judging device 35, so that the foreign object 5 appears on the image as shown in FIG. 3 (b).

3 (a) to 3 (d), the comparison unit 47 compares the coordinate position of the chip 4 to which the foreign object 5 is to be attached, that is, the coordinate position of the inspected object The obtained image (FIG. 3A) is compared with the coordinate position of the chip portion to which the foreign matter 5 is not attached, that is, the reference image at the coordinate position to be compared (FIG. 3B). 3 (d), the comparator 47 receives a pair of images of the same portion in the pair of adjacent chip portions 4, 4 and compares them . The difference image shown in Fig. 3 (c) is formed from the image to which the foreign object 5 of Fig. 3 (a) is attached and the reference image of Fig. 3 (b). Since the difference between the image shown in Fig. 3A and the image shown in Fig. 3B is the foreign matter 5, only the foreign matter image 6 is extracted as shown in Fig. 3C.

The comparison unit 47 transmits the extracted foreign object image 6 to the verification unit 48. [ When the foreign object image 6 is transmitted from the comparator 47 to the coordinate position of the foreign object 5 transmitted from the foreign object judging device 35, It is verified that the judgment of the existence of the foreign object is appropriate.

On the other hand, when the foreign object image 6 is not transmitted from the comparison unit 47 to the coordinate position of the foreign object 5 transmitted from the foreign object determining apparatus 35, It is verified that the determination of the presence of the foreign object made by the user is an error. When the error is verified, the verification unit 48 transmits the result to the host computer 36. [ In addition, reference numeral 100 denotes a monitor display unit that displays various information related to a foreign object and is processed by the host computer 36. [

The extracted foreign object image 6 is transmitted to the classification unit 49. [ The classifying unit 49 classifies the size, shape, color, and properties of the foreign matter 5, organic or inorganic, according to a predetermined algorithm. For example, as shown in Fig. 4 (a), the size of the foreign object image 6 can be specified in the vertical and horizontal directions by the coefficient of the number of pixels of the foreign object image 6. 4 (b), the area or size of the foreign object 5 can be specified by the product (a × b) between the vertical length a and the horizontal length b of the foreign object image 6 . The shape of the foreign object 5 is specified by the quotient a / b between the vertical length a and the horizontal length b of the foreign object image 6. For example, when a / b = 1, the foreign object 5 is specified as a circle as shown in Fig. 4 (c). When a / b > 1 or a / b < 1, the foreign matter 5 is specified in a slender shape as shown in Fig. 4 (d).

Since the white light 41 is used as the background illumination light, the color of the foreign object image 6 can be specified in accordance with the hue and brightness (that is, the grade that forms the image). As a result, for example, if the extracted foreign matter has a color and grade substantially similar to those of the dark blue system, the foreign matter can be assumed to be an insulating layer having a flat shape and a uniform thickness.

It is also possible to recognize the presence of the concave / convex surface on the surface by using the scattered light signal of the foreign object detected by the scattered light detector and the size and the attribute of the foreign object specified by the foreign object image 6. That is, when the inspection light irradiating device 20 irradiates the wafer 1 with the laser light 21 as inspection light at a low inclination angle, the scattered light 31 is generated in the foreign object 5 under dark background illumination. The intensity of the diffused light is changed in relation to the scattering cross-sectional area and the convex convexity of the surface. Therefore, by analyzing the intensity of the diffused light recorded at the time of detection and the length of the foreign object in the direction perpendicular to the laser irradiation direction calculated in the foreign image, It is possible to recognize the concave / convex state of the concave / convex portion. As a result, for example, when the convex convexity is small, the foreign matter is specified as an inorganic substance such as silica (glass), a silicon chip, or a metal chip. If there are many convex convexities, it is specified as organic matter such as dust generated by human or resin.

The sorting result classified as described above is transmitted from the classifying unit 49 to the host computer 36. The host computer 36 uses the classification data from the classifying section 49 and the data of the coordinate position and the number of the foreign object 5 from the foreign substance judging device 35, (d), and outputs it in a timely manner via an output device such as a monitor or a printer. Therefore, the operator can accurately and quickly manage the manufacturing process of the IC.

FIG. 5A is a diagram showing the size data of foreign objects and the sizes of foreign objects created by the coordinate position data. Fig. 5 (b) is a histogram shown by the size of the foreign object. In Fig. 5, the axis of abscissa is taken as a segmented variable, and the axis of ordinates is taken as the number of detected values belonging to each foreign particle size.

Fig. 5C is a diagram showing the shape of the foreign object created by the shape data of the foreign object and the coordinate position data. Fig. 5 (d) is a histogram shown by the shape of the foreign object, wherein the abscissa represents a foreign object as a segmented variable, and the abscissa represents the number of detected values belonging to each foreign object.

FIG. 5E is a time series transition graph of inspection results produced by inspection data, foreign object size data, foreign object data (for example, elongated shape), and attribute data. However, a lot number or a wafer number may be used instead of the time series.

According to the first embodiment, the following effects can be obtained.

[1] By specifying the size, shape, color, and properties of the foreign object in addition to the coordinate position of the foreign object by the foreign object inspection device, the operator can precisely and quickly manage the manufacturing process of the IC, .

[2] Since the determination of the detection unit in accordance with the detection of the scattered light detector is verified by the verification unit connected to the image pickup apparatus operating under bright field illumination, the inspection accuracy by the inspection apparatus can be improved, Thereby improving reliability.

[3] Since the size, shape, color, and property of the foreign object other than the coordinate position of the foreign object can be specified without using an external inspection device for foreign objects or a very expensive foreign object analysis device having a long inspection time, The time for inspection and review can be greatly shortened. As a result, the inspection of the total number of lots and the management of the IC manufacturing process by the operator can be accurately and quickly realized.

6 is a perspective view showing a first modification of the apparatus for inspecting a foreign object according to the present invention. FIG. 7 is a view showing a foreign matter inspection method performed using the foreign object inspection apparatus according to the first modification example, and FIGS. 8 (a) and 8 (b) are views showing the operation thereof.

The inspection apparatus 10A according to the first modified example is different from the above-described foreign matter inspection apparatus 10 in that an impact illumination apparatus 40 is commonly used together with an inspection light irradiation apparatus 20 in an optical system, (45A) are commonly used together with the scattered light detector.

In the inspection method using the foreign object inspection apparatus 10A according to the first modified example, as shown in Fig. 7, the coordinates (coordinates) of the foreign object 5 are first detected by the image pickup device 45A serving as both the scattered light detector and the foreign object determination device 35 The position is specified over the entire first main surface 2 of the wafer 1. This coordinate position is stored in a memory (not shown) of the host computer 36.

For example, as shown in FIG. 8 (a), the host computer 36 divides the group of foreign objects 5 on the entire first main surface 2 of the wafer 1 into groups And the representative of each group is sampled as an image pickup object. As a result, the number of objects to be imaged can be reduced, and the inspection time can be further shortened.

8 (b), the host computer 36 collectively groups the foreign objects 5 on the entire first main surface 2 of the wafer 1 (collectively, by the intensity of the scattered light, And the representative of each class is sampled as an image pickup object. This makes it possible to reduce the number of objects to be imaged, thereby further shortening the inspection time. Further, the host computer 36 designates the order of image pickup so that the image can be picked up at the shortest distance, thereby further shortening the inspection time and improving the inspection efficiency.

The coordinate position of the imaging object designated as described above is transmitted from the host computer 36 to the verification unit 48. [ When the coordinate position of the designated foreign object 5 comes into the spot of the scattered light detector combination image pickup device 45A or the spot from the fallowed illumination device 40, The comparator 47 receives the signal.

Thereafter, the comparator 47 receives the image signal of the same coordinate position of the adjacent chip 4. Next, the comparison unit 47 compares the image of the coordinate position at which the foreign object 5 should be attached and the image of the chip unit 4, which is not attached with the foreign object 5 received later, .

The comparison unit 47 transmits the extracted foreign object image 6 to the verification unit 48. [ When the foreign object image 6 is transmitted from the comparison unit 47 to the coordinate position of the foreign object 5 designated by the host computer 36, the verification unit 48 determines that the foreign object Is appropriate. On the other hand, when the foreign object image 6 is not transmitted from the comparator 47 to the coordinate position of the foreign object 5 designated by the host computer 36, the presence or absence of the foreign object made by the foreign object judging device 35 This error is verified. If it is determined to be an error determination, the verification unit 48 is transmitted to the host computer 36. [

The extracted foreign object image 6 is transmitted to the classification unit 49. [ The classifying unit 49 classifies the size, shape, color, and properties of the foreign matter 5, organic or inorganic, according to a predetermined algorithm. The classification result of the classified foreign object 5 is transmitted from the classification unit 49 to the host computer 36. [ The host computer 36 suitably forms various data by using the classification data from the classifying section 49 and the data of the coordinate position and the number of the foreign object 5 from the foreign substance judging device 35 and the intensity of the scattered light Timely output by an output device such as a monitor or printer.

9 is a perspective view showing a second modification of the foreign object judging device according to the present invention.

The inspection apparatus 10B according to the second modification differs from the above-mentioned foreign matter inspection apparatus 10 in that it includes an image pickup stage 40 for image pickup under bright illumination, which is composed of a drop lighting apparatus 40, an image pickup apparatus 45, 50) are provided.

Since the foreign object inspection method by the inspection apparatus 10B follows the inspection method executed in the first modification, detailed description thereof will be omitted. However, since the imaging stage 50 under the bright field illumination is provided in the foreign body inspection apparatus 10B according to the second modification, it is possible to shorten the inspection time as a whole by performing simultaneous processing of foreign object detection, specification of coordinate position and extraction of a foreign object image do.

FIG. 10 is a perspective view showing a third modification of the foreign substance inspection apparatus according to the present invention.

The inspection apparatus 10C according to the third modified example is different from the foreign matter inspection apparatus 10 in that the image pickup apparatus 45 is changed from the line sensor to the area sensor 45B.

The foreign object inspection method by the foreign object inspection apparatus 10C follows the inspection method executed in the first modification, and the inspection is executed according to the drawing shown in Fig. 7, and thus the detailed description thereof will be omitted.

Since the inspection apparatus 10C according to the third embodiment is provided with the image pickup device of the area sensor, it is possible to pick up the foreign object image in the stopped state of the stage, to easily obtain the high resolution image, .

While the present invention has been described in detail with reference to the embodiment thereof and modifications thereof, it is to be understood that the invention is not limited to the above-described embodiment and modifications, Of course it is possible.

For example, the specification of the position of the foreign object under the bright field illumination is not limited to the structure executed by the light shielding element, but can also be performed by a structure for comparing the data detected at the same position in the repeated pattern. In this case, the data to be compared can be detected data of adjacent chips, pre-stored design patterns, and standard patterns.

As the imaging device, not only a line sensor but also an area sensor or an image pickup tube can be used.

In the above description, the invention made by the inventors of the present invention is mainly described as a background of the present invention, but the present invention is not limited to this, and a plate including a photomask, a liquid crystal panel, The present invention can be applied to all foreign objects or defects inspection technology in the shape.

Hereinafter, effects obtained by the present embodiment and modifications will be briefly described.

By specifying the size, shape, color, and properties of the foreign object in addition to the coordinates of the defect or foreign object by the foreign material inspection apparatus, the operator can accurately and quickly manage the manufacturing process of the IC, thereby improving the IC production yield .

Since the determination of the foreign object detection position in accordance with the detection of the scattered light detector is verified by the verification unit connected to the image pickup apparatus operating under the bright field illumination, the accuracy of the inspection by the inspection apparatus can be improved and the quality and reliability .

The size, shape, color, and properties of the foreign object other than the coordinate position of the foreign object can be specified without using an external inspection device for foreign matter or a very expensive foreign substance analysis device having a long inspection time, Can greatly shorten the time for inspection and review. As a result, the inspection of the total number of lots and the management of the IC manufacturing process by the operator can be accurately and quickly realized.

Next, another embodiment according to the present invention will be described in detail with reference to the drawings. In this alternative embodiment, the inspection apparatus 10 is the same in structure as that shown in Fig. 1, and a description thereof will be omitted.

An inspection method according to another embodiment of the present invention, which is executed by the inspection apparatus 10 having the above structure, will be described with reference to FIG.

First, when the laser beam 21 is irradiated by the inspection light irradiating device 20 of the wafer 1 at a low inclination angle as inspection light in the same manner as shown in Fig. 2, the laser beam 21 is irradiated The scattered light 31 is generated under the dark background illumination in the foreign matter 5 and the circuit pattern (not shown) formed by adhering to the first main surface 2 of the wafer 1. [ The scattered light is condensed by the objective lens 32, and is image-formed on the scattered-light detector 34 via the relay lens 33.

At this time, scattered light from the circuit pattern 31 (not shown) is blocked by the light shielding element (not shown) made of a spatial filter or an analyzer provided on the Fourier transform surface of the pattern surface of the wafer 1 Is shielded from light. On the other hand, since the scattered light 31 from the foreign object 5 is irregular, it is imaged on the scattered light detector 34 passing through the spatial filter or the analyzer. Therefore, only foreign objects can be detected.

The detection signal detected by the scattered light detector 34 by the scattered light 31 from the foreign object 5 under the dark background illumination is input to the foreign substance judging device 35. [ The foreign substance judging device 35 judges the presence or absence of the foreign object 5 in accordance with the detection signal and combines the judgment data with the data of the coordinate position from the controller 14 of the stage device 11, 5). The coordinate positions thus specified are detected by, for example, a host computer 36 which comprehensively executes the foreign object inspection apparatus 10 in the foreign object judging device 35 and a comparator 47 electrically connected to the image capturing device 45, And is output to the verification unit 48.

When the coordinate position of the foreign object 5 transmitted from the foreign object judging device 35 comes to the imaging position of the imaging device 45, that is, the spot from the back lighting device 40, Lt; RTI ID = 0.0 > brightfield < / RTI > illumination. Since the foreign object 5 is attached to the coordinate position according to the action of the foreign object judging device 35, the foreign object 5 appears on the image as shown in Fig. 3 (a). That is, an image of the inspected object is obtained.

Thereafter, the coordinate position shifted by the distance of the one-chip portion 4 from the coordinate position of the foreign object 5 transmitted from the foreign substance judging device 35, that is, the coordinate position where the foreign substance 5 is attached, When the coordinate position corresponding to the coordinates of the foreign object 5 in the image pickup device 45 reaches the image pickup position of the image pickup device 45, the comparator 47 receives the image signal from the image pickup device 45 under bright illumination do. The foreign object 5 does not adhere to its coordinate position in accordance with the action of the foreign object judging device 35 and the foreign object 5 appears on the image as shown in Fig. 3 (b). That is, a reference image of the inspected object is obtained.

3 (a) to 3 (d), the comparison unit 47 compares the coordinate position of the chip 4 to which the foreign object 5 is to be attached, that is, the coordinate position of the inspected object In the obtained image (FIG. 3A), the coordinate position of the chip portion to which the foreign matter 5 is not attached, that is, the reference image (FIG. 3B) at the coordinate position to be compared is subtracted. 3 (d), the comparator 47 receives a pair of images of the same portion in a pair of adjacent chip portions 4, 4, and performs arithmetic processing or subtraction State. By this subtraction, the difference image shown in Fig. 3 (c) is formed from the image to which the foreign object 5 of Fig. 3 (a) is attached and the reference image of Fig. 3 (b). Since the difference between the image shown in Fig. 3A and the image shown in Fig. 3B is the foreign matter 5, only the foreign matter image 6 is extracted as shown in Fig. 3C.

The comparison unit 47 transmits the extracted foreign object image 6 to the verification unit 48. [ When the foreign object image 6 is transmitted from the comparator 47 to the coordinate position of the foreign object 5 transmitted from the foreign object judging device 35, It is verified that the judgment of the existence of the foreign object is appropriate. On the other hand, when the foreign object image 6 is not transmitted from the comparison unit 47 to the coordinate position of the foreign object 5 transmitted from the foreign object determining apparatus 35, It is verified that the determination of the presence of the foreign object made by the user is an error. When the error is verified, the verification unit 48 transmits the result to the host computer 36. [

The extracted foreign object image 6 is transmitted to the classification unit 49. [ The classifying unit 49 classifies the size, shape, color, and properties of the foreign matter 5, organic or inorganic, according to a predetermined algorithm. For example, as shown in Fig. 4 (a), the size of the foreign object image 6 can be specified in the vertical and horizontal directions by the coefficient of the number of pixels of the foreign object image 6. 4 (b), the area or size of the foreign object 5 can be specified by the product (a × b) between the vertical length a and the horizontal length b of the foreign object image 6 . The shape of the foreign object 5 is specified by the quotient a / b between the vertical length a and the horizontal length b of the foreign object image 6. For example, when a / b = 1, the foreign object 5 is specified as a circle as shown in Fig. 4 (c). When a / b > 1 or a / b < 1, the foreign matter 5 is specified in a slender shape as shown in Fig. 4 (d).

Since the white light 41 is used as the background illumination light, the color can be specified in accordance with the hue and brightness of the foreign object image 6 (that is, the image forming grade). As a result, for example, if the whole of the extracted foreign matter has a color and grade substantially similar to those of the dark blue system, the foreign matter can be assumed to be an insulating layer having a flat shape and an almost uniform thickness.

It is also possible to recognize the presence of the concave / convex surface on the surface by using the scattered light signal of the foreign object detected by the scattered light detector and the size and the attribute of the foreign object specified by the foreign object image 6. That is, when the inspection light irradiating device 20 irradiates the wafer 1 with the laser light 21 as inspection light at a low inclination angle, the scattered light 31 is generated in the foreign object 5 under dark background illumination. The intensity of the diffused light is changed in relation to the scattering cross-sectional area and the convex convexity of the surface. Therefore, by analyzing the intensity of the diffused light recorded at the time of detection and the length of the foreign object in the direction perpendicular to the laser irradiation direction calculated in the foreign image, It is possible to recognize the concave / convex state of the concave / convex portion. As a result, for example, when the convex convexity is small, the foreign matter is specified as an inorganic substance such as silica (glass), a silicon chip, or a metal chip. If there are many convex convexities, it is specified as organic matter such as dust generated by human or resin.

The sorting result classified as described above is transmitted from the classifying unit 49 to the host computer 36. The host computer 36 uses the classification data from the classifying section 49 and the data of the coordinate position and the number of the foreign object 5 from the foreign substance judging device 35, (d), and outputs it in a timely manner via an output device such as a monitor or a printer. Therefore, the operator can accurately and quickly manage the manufacturing process of the IC.

However, when the foreign object is stuck on the adjacent wiring pattern, if the reference image of the inspected object at the coordinate position is subtracted from the image of the object at the coordinate position, as shown in Fig. 12C, It has been discovered by the inventors of the present invention. The reason why this phenomenon occurs can be considered as follows.

12A shows an image of an object to be inspected at a coordinate position. A pair of wiring pattern images 8 and 8 are provided on the background image 7 in parallel with each other. The foreign matter image 6 appears on the images 8 and 8 over the whole image. FIG. 12B is a diagram showing a reference image of an object to be inspected at a coordinate position, and only two wiring pattern images 8 and 8 appear on the background image 7. FIG.

Assuming that the value of the binary image signal of the background image 7 is white when the comparison unit 47 performs subtraction, the value of the foreign image 6 corresponds to black, and the wiring pattern image 8 corresponds to It corresponds to gray. 12 (b) is subtracted from FIG. 12 (a), the difference image 9 remains in a light gray state in the foreign image 6 in the wiring pattern. However, when this difference image is processed as a binary signal, the binarized difference image 90 is divided into three by the images 8 and 8 of both wiring patterns as shown in Fig. 12 (c) .

If the foreign object image 6 is recognized as being in the divided state, the classification unit 49 may be classified as a continuous small foreign object. In other words, there is a possibility that the foreign object 5 may be determined as a minute defect or foreign matter which causes a fatal defect such as disconnection or short-circuit and does not cause a fatal defect. For example, in the foreign matter inspection step after the wiring pattern formation step, foreign matter of metal spanning wiring patterns is misjudged as microbes existing between the wiring patterns, so that short-circuit foreign matter is omitted, and measures against fatal defects are delayed . As a result, the yield rate is lowered. Therefore, even when the difference image 90 is recognized as being small, it is necessary to judge whether it is a foreign object image divided by the wiring pattern or a foreign object existing between the wiring patterns.

In the present embodiment, whether or not the divided difference image is judged by the following algorithm in the dividing section 49 is determined. 12 (c), the difference image 90 is divided into three or more, that is, the left split image 91, the center split image 92 and the right split image 93 by the adjacent wiring pattern, As shown in Fig.

The distance d between the left split image 91 and the center split image 92 and the distance d between the center split image 92 and the right split image 93 as shown in FIG. 12 (c) The width L of the image 8 is subtracted. When the value of the difference due to the subtraction becomes a value equal to or smaller than a preset value?, It is recognized that the difference image 90 is a single foreign object. 12 (d), the width X of the wiring pattern image 8 in the direction orthogonal to the difference image 90 is the left end of the left divided image 91 and the right divided image 93 ) ≪ / RTI > As described above, it is determined that a foreign matter determined as a single difference image 90 is a fatal defect.

The left divided image 91, the central divided image 92 and the right divided image 93 are recognized as individual minute defects when the value of the difference due to the subtraction is larger than a predetermined value? Is measured as the size of each defect. If the size of the left split image 91, the center split image 92 and the right split image 93 is larger than the distance S between the wiring pattern images 8 and 8, That is, it is judged as a defect candidate, and if it is smaller than that, it is judged that there is no possibility of occurrence of a fatal defect.

As shown in Fig. 13C, the distance between the left split image 94 and the right split image 95 when divided into the left split image 94 and the right split image 95, The pattern width L is obtained by subtraction of d. When the value of the difference due to the subtraction is smaller than the preset value?, It is determined that the image is a single difference image. 13 (c), the width X of the wiring pattern image 8 in the direction orthogonal to the difference image 90 is the left end of the left divided image 94 and the right divided image 95 ) ≪ / RTI > Then, this foreign matter is judged to have a possibility of causing a fatal defect, that is, a defect candidate.

When the value of the difference due to the subtraction is larger than a predetermined value?, The left split image 94 and the right split image 95 are recognized as individual minute defects or foreign objects, . If the sizes of the left split image 94 and the right split image 95 are larger than the distance S between the wiring pattern images 8 and 8, it is determined that there is a possibility of causing a fatal defect, that is, It is determined that there is no possibility of causing a fatal defect.

The information of all the foreign objects detected and determined as described above and the judgment result of the fatal defect or the defect candidate are summarized and displayed as shown in Table 1 below.

Further, the coordinates of the chip and the coordinate position of the chip among the information on the foreign object can be obtained by detection by diffused light, and more detailed information such as defect size, fatal defect, So you can get it. Various kinds of information related to the foreign object are displayed on the screen of the monitor display unit 100 in combination.

Defect number Chip coordinates Coordinate position in chip Defect Size Fatal flaw / beach flaw Xc Yc X Y X Y U V domain One 0 6 1998 812 1.51 1.55 1.29 0.46 1.8 2 2 3 9234 1364 1.15 8.91 3.72 0.65 7.2 3 2 8 8519 705 1.65 2.61 1.15 0.95 3.3 Defective candidate 4 2 10 7891 2910 0.49 2.3 1.94 0.14 0.8 5 4 4 359 1007 1.47 2.22 1.1 0.76 2.5 Fatal defect 6 4 10 6519 2017 1.2 5.22 1.78 0.83 4.4 Defective candidate ... ... ... ... ... ... ... ... ... ... ... 22 12 6 214 4913 1.76 0.89 1.58 0.25 1.2 23 13 8 1705 3279 0.84 2.2 1.53 0.29 1.3 Fatal defect

The inspection results such as wafer inspection information, the number of foreign objects, the yield of the wafers per process, and the like are summarized as shown in Table 2.

Inspection Wafer Information product name 256M DRAM Lot ID 123456 Wafer ID ABC Number of chips 157 Chip area (㎠) 1.56 Inspection process Inspection after completion of the 1st layer wiring Inspection time 1998.02.24 10:18 Foreign matter / defect number Total function of wafer 23 Ratio of total function Number of fatal defects 5 22% Defect Candidates 8 35% Chip yield Defect detection chip number 10 Ratio of total chips Critical Defect Chips 4 2.5% Defect Candidate Chip Number 6 3.8% Chip goodness ratio 93% Chip reject rate 3% Defect density Defect density (number / cm2) maximum 0.05 at least 0.02 Defective wafer density (number / cm2) maximum 0.05 at least 0.02

Here, the chip yield rate yi is a ratio of the number of chips to the total chip without a fatal defect and a defect candidate, and the chip defect rate fi is a ratio of the number of chips to the total number of fatal defective chips. The defect density is the number of foreign matters and defects per unit area. The defect density is expressed by the maximum and minimum values of two kinds, that is, the estimated range according to the following definition. That is, the defect density Di is

Di (max.) = - (1 / A) Ln (yi)

Di (min.) = - (1 / A) x Ln (1-fi)

A is the chip area, and Ln is the natural logarithm.

Defective wafer density Wi

Wi (max.) = (Number of critical defects + number of defects) / (number of product chips)

Wi (min.) = (Number of critical defects) / (A x number of chips).

In addition, as shown in Fig. 14, a fatal defect and a defective chip are displayed during wafer display.

When the inspection of one lot is completed, inspection result information is displayed on the screen of the display device (not shown) of the apparatus, for example, for each lot as shown in Tables 3 and 4 below. The inspection result information is transmitted to an external system such as an inspection information analysis system.

product name 256M DRAM Lot ID 123456 Wafer ID ABC Chip number 157 Chip area (㎠) 1.56 Inspection process Inspection after completion of the 1st layer wiring Test date and time 1998.02.24 10:18

Wafer ID Information on detection defects Information on the number of chips Chip goodness ratio Defect density (number / cm2) Di Wi AA-1 AA-2 AA-3 BB-1 BB-2 BB-3 CC-1 CC-2 maximum at least maximum at least ABA 18 4 5 9 4 5 0.94 0.03 0.04 0.02 0.08 0.02 ABB 26 8 15 22 8 14 0.86 0.05 0.10 0.03 0.07 0.03 ABC 23 5 8 10 4 6 0.94 0.03 0.04 0.02 0.05 0.02 USA 17 3 8 11 3 8 0.93 0.02 0.05 0.01 0.07 0.01 ABE 22 6 13 15 6 9 0.90 0.04 0.06 0.02 0.10 0.02 ABF 24 6 18 24 6 18 0.85 0.04 0.11 0.02 0.02 0.02 ... ... ... ... ... ... ... ... ... ... ... ... ...

In the above table, symbols are as follows.

AA-1: Prime function of wafer

AA-2: Number of fatal defects

AA-3: Number of defect candidates

BB-1: Chip with detection defect

BB-2: Chips with fatal defects

BB-3: Number of Chips with Defect Candidates

CC-1: Chip yield

CC-2: Chip defect rate

Since the inspection apparatus of the scattered light detection type only detects the foreign object on the outermost surface of the wafer, if foreign matter exists on the pattern, defects of the product occur. By controlling the yield rate and the defect rate, it is possible to predict the yield rate in the final inspection of the product. It is also possible to determine whether or not the foreign object is random by the distribution of the defective chips. If the foreign object is a random object, assuming that the foreign object has a Pawson distribution,

yi = exp (-A x Di) (where A is the chip area)

. It is also possible to calculate the defect density Di of each step (here, the suffix i represents the number of steps). Therefore, countermeasures against foreign matters or defects of the process by the degree of discrepancy with the value for managing the defect density distributed to each process can be implemented. Unlike the conventional method in which the defect density is calculated in the number of foreign objects or defects and the inspection area, the method of managing foreign matter or defects in such a process,

y = exp (-A x D) where y is the yield rate, A is the chip area, and D is the defect density.

The defect density Di is calculated. Therefore, it is possible to extract a process that has a direct effect on the improvement of the yield rate in the final process.

That is, according to the other embodiment, the following effects can be obtained.

[1] Since the size of the foreign object can be outputted without using an apparatus having a long inspection time or a plurality of inspection apparatuses, it is possible to remarkably shorten the time required for inspection per wafer and consequently contribute to improvement in early yield rate .

[2] By providing the inspection data directly related to the defect density reduction of the model of the yield rate in the probe inspection, it is possible to determine the point of improvement of the yield rate and the application of the measure in a short period of time.

[3] Since the detection of the detection unit is verified by the verification unit connected to the image pickup apparatus operating under bright field illumination in accordance with the detection of the scattered light detector, the inspection accuracy in the foreign material inspection apparatus can be improved, It is possible to improve the quality and reliability of the foreign object inspection apparatus.

[4] It is possible to measure the particle size more accurately by determining whether or not the divided portion is a single foreign matter and measuring the particle diameter.

[5] It is possible to determine the fate of the foreign object (that is, the fatal defect or the defective flaw) in the size and attribute of the foreign object pattern and the foreign object, and thus the efficiency of the foreign object inspection method can be further improved.

[6] Since the yield rate and defect density of chips to be inspected can be calculated, the utilization efficiency of the foreign matter inspection method can be further improved.

Fig. 15 is an explanatory view for explaining the recognition operation of a single foreign object in the first modification of the inspection method. Fig.

The present modified example is different from the above-described embodiment in a single foreign object recognition method in the case where a foreign object image is divided by a wiring pattern image. That is, when the difference image 90 is divided into three as shown in Figs. 15A, 15B and 15C, the color determination of the divided image is performed by the subtraction processing.

When the image by the image pickup device 45 is a color image and is output as an NTSC (National Television System Committee) signal, the color determination is executed using the saturation color distribution chart shown in Fig. 15 (d). If the left divided image 91, the central divided image 92 and the right divided image 93 are determined to be the same color in the predetermined ranges of DELTA gamma and delta & theta, they are recognized as a single difference image 90, The measurement of the foreign object size in which the images are gathered together is executed and it is judged as a fatal defect. If it is determined that they are not the same color, they are recognized as foreign matters separated from each other and a size measurement is performed for each of them. If the size of the foreign object is larger than the distance between the patterns, it is determined to be a fatal defect.

When the image by the image pickup device 45 is a color image and is output by an RGB signal,

Δα + Δβ + Δγ

, And a predetermined value < RTI ID = 0.0 >

| ?? | + | ?? | + | ?? | |?

The same color is determined. If the divided images are determined to be the same color as described above, they are recognized as a single foreign object, the divided images are collectively arranged, the foreign particle diameter is measured, and a fatal defect is determined. If it is determined that they are not the same color, they are recognized as foreign matters separated from each other and a size measurement is performed for each of them. If the size of the foreign object is larger than the distance between the patterns, a fatal defect is determined.

As shown in Fig. 16, even when the number of divisions is two, the same processing is performed as in the case where the color judgment of the divided image is divided into three or more. If it is judged to be the same color, it is recognized as a single foreign object, the divided images are collectively arranged, the foreign object diameter is measured, and this foreign object is judged as a defect candidate. In addition, the inspection result is processed in the same manner as in the other embodiments.

FIG. 17 is an explanatory diagram for explaining the recognition operation of a single foreign object according to a second modification of the foreign object inspection method according to another embodiment of the present invention.

This modified example differs from the above-described other embodiments in a single foreign object recognition method in a case where a foreign object image is divided by a wiring pattern image. That is, as shown in Figs. 17A, 17B, and 17C, the determination is performed by the expansion process of the divided image.

17, when the image is divided into the left divided image 91, the central divided image 92 and the right divided image 93, each element of the divided image is processed, And is caused to expand as shown in Fig. 17 (d). In this modification, the numerical value zeta is set to the same numerical value as the space width between the patterns. As a result of the expansion processing, when the number of images after the expansion processing is smaller than the number of original images, the division elements are collectively grouped into one and recognized as a single foreign body. The measurement of the foreign object size is carried out by measuring the distance between the left end of the original left divided image 91 and the right end of the right divided image 93, and a single foreign object is judged as a fatal defect. If the number of images after the expansion processing is equal to the number of original images, this foreign matter group is recognized as foreign matter separated from each other and determined as a defect candidate. However, the inspection result is processed in the same manner as in the other embodiments.

FIGS. 18A to 18B are explanatory diagrams for explaining a single foreign object recognizing operation according to the third modification of the foreign object inspection method according to another embodiment of the present invention. FIG.

This modified example differs from the above-described other embodiments in a single foreign object recognition method in a case where a foreign object image is divided by a wiring pattern image. That is, as shown in (a), (b), and (c) in FIG. 18, the determination is performed by the sum image.

18A shows an image of coordinate positions of an object to be inspected. A pair of wiring pattern images 8 and 8 are provided on the background image 7 in parallel with each other. So that the foreign object image 6 appears on the pattern images 8 and 8. 18B is a diagram showing an image of a reference object at a coordinate position of a reference object, and only the two wiring pattern images 8 and 8 are shown on the background image 7. FIG. The image of the inspected object and the wiring pattern images 8 and 8 are added to form a sum image 9 'as shown in FIG. 18 (c). The threshold value processing is executed for the sum image 9 'to form the wiring pattern images 8' and 8 'divided by the foreign image 6 shown in FIG. 18 (d) . If the divided image is recognized in this way, the foreign object is judged to be a fatal defect. If it is not recognized, it is judged to be defective. The inspection results are processed in the same manner as in the above embodiment.

Although the invention made by the present inventors has been described concretely with reference to the embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and that various changes can be made without departing from the gist of the present invention.

For example, the specification of the position of the foreign object under the bright field illumination is not limited to being performed by the light-shielding element, and may be performed by comparing detection data at the same position in the repeated pattern. In this case, the data to be compared may be detection data of the adjacent chip, a previously stored design pattern, or a standard pattern.

As the image pickup device, not only a line sensor but also an area sensor, an image pickup tube and the like can be used.

In the above description, the invention made by the inventors of the present invention is mainly described as a background of the present invention, but the present invention is not limited to this, and a plate including a photomask, a liquid crystal panel, The present invention can be applied to all foreign objects or defects inspection technology in the shape.

Effects obtained by representative ones of the inventions disclosed in the present application will be briefly described as follows.

It is possible to output the size of the foreign object without using an apparatus having a long inspection time or a plurality of inspection apparatuses, so that it is possible to greatly shorten the time required for one inspection object per inspection. It is possible to more accurately measure the size of the foreign object by determining whether or not the divided portion is a single foreign object and measuring the size. The efficiency of the foreign matter inspection method can be further improved by determining the fate of the foreign object (that is, the fatal flaw or the defective flaw name) in the size and the attribute of the pattern and the foreign object.

The utilization efficiency of the foreign matter inspection method can be further improved by calculating the yield rate and defect density of chips to be inspected.

Claims (20)

A method for inspecting a foreign substance in a micro-repeated pattern formed on a surface of an object to be inspected, A step of irradiating the inspection light onto the surface of the inspection object on which the ultra-small repeating pattern is formed by the inspection light irradiation device, A step of detecting at least scattered light of the inspection light scattered on the surface of the inspected object with at least a scattered light detector, A step of determining a coordinate position of a foreign object on the surface of the inspected object in accordance with the detection of the scattered light in the step, Capturing an image of the foreign object whose coordinate position has been determined in the process under bright field illumination by the irradiation means at the coordinate position corresponding to the coordinate position in the scattered light detection step; And determining at least one of the size, shape, color, and attribute of the foreign object as foreign matter according to the image of the foreign object extracted according to the image captured in the process. The method according to claim 1, Further comprising the step of capturing an image at another position of the micro repeat pattern of the inspected object under bright field illumination by the irradiation means at a position corresponding to the coordinate position of the foreign object determined by the detection of the scattered light, And comparing the two captured images to extract an image of a foreign object in the determining step. The method according to claim 1, Further comprising the step of verifying the legitimacy of the determination made in the determining step of the coordinate position of the foreign object upon detection of the scattered light in accordance with the foreign matter determined in the image captured in the imaging step. The method according to claim 1, Wherein the shape is determined in the determining step using the size of the image of the foreign object obtained in the imaging step. The method according to claim 1, Wherein the color is determined in the determining step using color components and gradations of the image of the foreign object obtained in the imaging step. The method according to claim 1, Wherein the attribute is determined in the determining step using scattered light from the detected foreign object detected by the scattered light. An apparatus for inspecting a foreign substance of a micropattern repeated pattern formed on a surface of an object to be inspected, A light irradiating device for irradiating inspection light onto the surface of the inspected object on which the micro- A scattered light detector for detecting scattered light of the inspection light scattered on the surface of the inspected object, Means for determining a coordinate position of the foreign object on the surface of the inspected object in accordance with the detection of the scattered light, Irradiating means for applying bright field illumination onto the surface of the inspected object on which the micropatterned pattern is formed, Means for capturing an image of the foreign object determined by the coordinate position under bright field illumination by the illuminating means at a coordinate position corresponding to the coordinate position determined by the coordinate position determining means; And means for determining at least one of a size, a shape, a color, and an attribute of the foreign object as a foreign object in accordance with the image of the foreign object extracted according to the imaging of the image obtained by the imaging means. 8. The method of claim 7, Wherein the image pickup means and the scattered light detection means are configured to be commonly used. 8. The method of claim 7, Wherein the stage for picking up the image by the imaging means under the bright field illumination by the irradiation means is provided separately from the stage for detecting the scattered light under the inspection light from the light irradiation device. 8. The method of claim 7, Means for obtaining a reference image by imaging an image of the micropattern under bright field illumination at a different coordinate position on the surface of the inspected object that is different from the coordinate position determined by the determination means and corresponding to the coordinate position; Further comprising means for obtaining an image subjected to arithmetic processing between the object image and the reference image, Wherein the determining means determines whether or not a defect exists in a coordinate position determined on the predetermined object to be inspected according to the arithmetic processing image obtained by the means for obtaining the arithmetic processed image. 11. The method of claim 10, And the means for obtaining the computed image obtains another image processed between the inspection object image and the reference image. 11. The method of claim 10, And the means for obtaining the computed image obtains an additional image processed between the inspection object image and the reference image. An apparatus for inspecting a foreign matter of a micropattern repeated pattern formed on a surface of an object to be inspected, A light irradiating device for irradiating inspection light onto the surface of the inspected object on which the micro- A scattered light detector for detecting scattered light of the light scattered on the surface of the inspected object, Means for obtaining first information related to a foreign substance attached on the surface of the inspected object obtained by the detection of the scattered light by the scattered light detector, Irradiating means for applying bright field illumination onto the surface of the inspected object on which the micropatterned pattern is formed, Means for capturing an image of the foreign object under bright field illumination by the irradiating means, Means for obtaining second information related to the foreign object in accordance with the image of the foreign object obtained in accordance with the image capturing by the image capturing means under the bright field illumination; And means for displaying the first information and the second information related to the foreign object on the display screen. A method for inspecting a foreign substance in a micro-repeated pattern formed on a surface of an object to be inspected, A step of capturing an image of the micropattern under bright field illumination at a coordinate position on the surface of the object to be inspected in advance to obtain an inspected object image, Capturing an image of the micropattern under bright field illumination at a different coordinate position corresponding to the coordinate position and different from the coordinate position on the surface of the inspected object to obtain a reference image; A step of obtaining an image subjected to arithmetic processing between the inspection object image and the reference image and And determining whether or not the foreign object exists at a predetermined coordinate position on the object to be inspected according to the condition of the image subjected to the arithmetic processing. 15. The method of claim 14, Wherein the computed image is a difference image between the inspection object image and the reference image. 15. The method of claim 14, Wherein the computed image is a sum image of the inspection object image and the reference image. 15. The method of claim 14, The predetermined coordinate position on the surface of the inspected object is a position of the foreign object as a position of the foreign object to be detected by detecting the scattered light on the surface of the micro- method of inspection. 15. The method of claim 14, Wherein at least two identical patterns are repeatedly formed on the surface of the object to be inspected and the position of the reference image is the same as the position of the object on the respective coordinates of the at least two patterns. 16. The method of claim 15, Wherein said determining step determines that said difference image is defective when said difference image is separated into at least two or more images. 17. The method of claim 16, Wherein the determining step compares the sum image with a predetermined value and determines that the defect is a defect when at least two or more images are obtained as a result of the comparison.