JP2011012971A - Method of performing visual examination and visual examination device for performing examination by the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of performing visual examination of aggregate of objects to be examined represented by, for example, a wafer in which semiconductor chips are integrated, to provide a visual examination device for performing examination by the method, and to especially perform a visual examination efficiently even if the respective objects to be examined are positioned randomly.SOLUTION: When performing a visual examination for detecting defects in a number of objects to be examined formed as aggregate of the objects to be examined, it is necessary to perform examination for a number of times by the number of types and angles of illumination and the number of imaging magnifications to be changed along examination recipe conditions. However, by storing the amount of deviation of angles of the respective objects to be examined from a reference horizontal angle as correction data, the stored information is called from the next repetition examination, and a visual examination is performed after correction, thus avoiding measurement work of positions and rotary angles each time and hence reducing visual examination time.

Description

  The present invention relates to an appearance inspection method and apparatus for an object to be inspected on which a fine pattern such as a semiconductor chip (hereinafter referred to as “chip”) is formed. In particular, the present invention relates to an appearance inspection method and / or apparatus that can be performed at high speed even when the arrangement and rotation angle of an object to be inspected are not uniform, such as a large number of chips on a wafer that has undergone an expanding process after dicing.

  In a visual inspection method and apparatus for an inspection target object on which a large number of fine circuits placed on a wafer are formed, each chip to be inspected is like a chip on a wafer that has undergone an expanding process after dicing. When there is a positional deviation or an angular deviation, as a method for correcting the position and angle of each inspection object in the captured image, at least two partial images in each inspection object are extracted, and the coordinates on the image are The position and the angle are corrected by setting the coordinates each time and extracting the coordinates of the points that can be specified from the plurality of partial images in the captured image.

  In addition, in the appearance inspection of an object to be inspected, an inspection recipe is set for each wafer on the same wafer. The inspection object was repeatedly inspected many times, and a lot of time was required for the appearance inspection for each wafer unit. (For example, Patent Document 1)

JP 2004-0669645 A

  As described in the background art, in the appearance inspection method for detecting defects in the inspection object, when correcting the position and angle of the inspection object to be imaged at the appearance inspection, for each chip that is the inspection object, In each case, at least two partial images are extracted and set as patterns, coordinates are specified from a plurality of patterns, correction positions and angles of captured images are calculated, corrected, and post-inspection is performed. Therefore, it is necessary to extract at least two partial images as pattern images for each chip that is an object to be inspected, and there is a problem of reducing the time for extracting position data that is repeatedly performed.

  In particular, when, for example, 10,000 chips for an object to be inspected exist on a wafer composed of an aggregate of an object to be inspected, as described above, at least two partial images are in each case. In the method of extracting a pattern, even if the extraction time is short individually, it cannot be ignored in consideration of repeated appearance inspections with different numbers and conditions.

  In a wafer in which chips as inspection objects are integrated, in general, a plurality of conditions in an inspection recipe are changed, and whether or not it is a non-defective product is determined using captured images. For example, it is necessary to repeatedly inspect for each condition as many times as the number of multiplications such as the state of illumination and the magnification of the magnifier. Specifically, typical illumination methods include IC patterns, LCD pattern marks, silicon wafer ID codes, etc., perpendicular to each inspection object along the optical axis of the specular lens. There are coaxial epi-illumination to illuminate, obliquely illuminating light that irradiates each object to be inspected from an oblique direction with respect to an object such as a surface with many irregularities that is not a mirror surface, and scratches and cracks.

  Furthermore, conditions for the inspection recipe are added, and in order to take an image in a state where it is easy to find out whether or not each inspection object is a non-defective product, the conditions are selected such that the magnification of the magnifying glass is x2 or x5. Therefore, as a result, the number of inspections for each chip easily overlaps 4 or 5 times for each object to be inspected.

  As described above, the inventor of the present application seeks an improvement in the correction of the angle and position of the chip, which is a large number of objects to be inspected, and each of the objects to be inspected formed on the aggregate of the objects to be inspected. In the inspection method for determining whether or not the product is a non-defective product, the position and angle correction of the inspection target object on the stage of the appearance inspection apparatus that captures images at the time of inspection are performed at least for the same chip to be inspected When performing a round inspection, information on the measured angle and position corresponding to each inspection object calculated in the first inspection is stored and reused when necessary, so that at least two locations for each inspection object are stored. The present inventors have found a method of avoiding the task of specifying angle information by extracting partial image patterns.

In the inspection target object comprising the chips on the wafer that has undergone the expanding process after dicing the wafer of the present invention, the appearance inspection method for the inspection target object for determining whether or not each of the inspection target objects is non-defective is claimed in claim As described in 1, “In the appearance inspection method for a large number of objects to be inspected on a wafer,
When a plurality of inspections with different conditions are repeatedly performed on an inspection target object on the same wafer, one coordinate obtained in advance for each inspection target object, a reference angle obtained from the reference inspection target object, and the inspection target It is characterized in that a position correction is performed using a stored correction angle that is a difference from a measurement angle obtained from an object, and an appearance inspection of the object to be inspected is performed ”.

(Action / Effect)
When performing a visual inspection of a chip, which is a large number of objects to be inspected on a wafer, the same chip is imaged many times based on the inspection recipe, and defects are extracted with as few position correction conditions as possible. Therefore, it is required to reduce the inspection time and to carry out efficiently by determining the position of the image at the time of repetition. Based on such a situation, in the present invention, a chip that is an object to be inspected is determined by correcting the position using one coordinate and a rotation correction angle that has already been measured and stored for determining the image position at the time of repetition. Inspection time will be shortened by performing visual inspection.

Furthermore, as described in claim 2 or claim 4, in the method and apparatus for inspecting the appearance of a large number of objects to be inspected on a wafer, one of the large number of objects to be inspected is subjected to a first inspection. A step and means for extracting a straight line as a reference from a wiring pattern on the inspection target object with respect to the first inspection target object;
A step and means for rotationally correcting and leveling the first object to be inspected in a predetermined direction with respect to the inclination of the reference straight line;
An angle between a direction of a straight line obtained by combining at least two coordinate points obtained from the wiring pattern inside the first inspection object and connecting the at least two coordinate points and the rotation-corrected horizontal straight line A process and means for extracting as a base angle;
A step and means for setting a plurality of appearance inspection conditions for the object to be inspected;
For all the objects to be inspected other than the first object to be inspected, a straight line is created by combining at least two coordinate points determined from the wiring pattern in the same manner as described above, and the combined linear directions And a step and means for extracting a difference in angle between the rotation-corrected first straight object to be inspected and a horizontal straight line as a measurement angle;
Storing the difference between each basic angle and each measurement angle as a correction angle for each object to be inspected, and means;
For each inspected object to be inspected, there is a step and means for performing angle correction using information of each stored correction angle and correcting the position using any one coordinate point of the plurality of locations. Method and apparatus for inspecting appearance of object to be inspected. ".

(Action / Effect)
As a result, as described above, in performing an appearance inspection to find out whether or not the relevant object to be inspected is a non-defective product, the type and angle of illumination applied for inspecting the object to be inspected, and the magnification of imaging The appearance inspection is performed to determine whether the inspection target is a non-defective product by repeatedly changing various conditions. It is a process for the preparation. First, it recognizes from a wiring pattern or the like inside the inspection object set inside the inspection object and a straight line as a reference of one representative inspection object. Using the difference angle between the coordinate point 1 at the upper left end and the coordinate point 2 at the lower right end as the base angle, the coordinate points 1 at the upper left end and the lower right end are similarly set for all other objects to be inspected. The coordinate point 2 is detected, a straight line connecting them is obtained, an angle formed with the horizontal straight line is set as a measurement angle, and a difference from the basic angle is stored as a correction angle.

  In many inspections with different conditions thereafter, when correcting the position and angle of an image, the stored individual correction angles are extracted and coordinate point information of any of a plurality of patterns obtained from the image is used. Position correction is performed, angle correction is performed using the information of the measured correction angle, position correction is performed using the obtained coordinate points, and the inspection is repeated to determine whether each inspection object is a non-defective product. .

  Further, in claim 3 and claim 5, “inspecting the object to be inspected a plurality of times based on a plurality of inspection conditions for the object to be inspected, in the second and subsequent inspections, from either one of the patterns. A position correction is performed using one obtained coordinate point, and a reference angle obtained from a reference inspection object stored in a computer for each inspection object and a measurement angle obtained from the inspection object The image is rotated and corrected using the correction angle formed by the difference between and the appearance inspection is performed ”.

(Action / Effect)
This is a matter indicating the basis of the invention of the application. As described in claim 2 and claim 4, first, a straight line that serves as a reference for one representative inspection object and the inspection object The same applies to all other objects to be inspected, with the difference angle between the straight line connecting the coordinate point 1 at the upper left end and the coordinate point 2 at the lower right end recognized from the wiring pattern or the like set inside the base pattern as the base angle. Then, the coordinate point 1 at the upper left end and the point coordinate 2 at the lower right end are detected, the measurement angle formed by the straight line connecting them and the reference straight line is obtained, and the difference from the basic angle formed by the horizontal straight line is taken as the correction angle. Remember. In subsequent inspections for many equivalent objects to be inspected with different conditions, in correcting the position and rotation of the image, each of the objects to be inspected obtained in claims 2 and 4 is stored. Individual correction angles are extracted and used to correct the position and rotation of the image, and sequentially determine whether the product is a non-defective product.

  In the first step of the appearance inspection of the inspection target object, recognition is made from a straight line as a reference of the first inspection target object and a wiring pattern or the like inside the inspection target object set in the inspection target object. Obtain and hold the difference angle between the straight line connecting the coordinate point 1 at the upper left end and the coordinate point 2 at the lower right end as the basic angle, and sequentially extract the wafer chip and determine the angle with the reference straight line. The second time to be performed on the inspection object of the same wafer based on the inspection recipe, which is obtained as the measurement angle and the difference from the basic angle is obtained and stored as the correction angle for all the chips that are the inspection object. In subsequent inspections under different conditions, the captured image is rotated using each of the stored correction angles, and alignment is performed using any one of the coordinate points. The correction angle was measured, without calculation, characterized in that it is accurate appearance inspection.

  In the above description, a plurality of arbitrary locations are selected for the image inside the object to be inspected, a pattern is set, a coordinate point is specified, and the coordinate point is used every time the condition is changed based on the inspection recipe. . In the description of the application, the location of the pattern is specified so that the pattern is provided in the upper left end and the lower right lower portion of the object to be inspected. This is to clarify the explanation, and the pattern setting location is specified. Not specific. Depending on the wiring in the image and the situation of the chip image, an optimal location is appropriately selected, a pattern is set, and the coordinate point is specified, and is not limited to the description.

  In the present invention, in a method and an apparatus for inspecting an appearance of an object to be inspected in which a fine pattern is formed, such as a chip on a wafer that has undergone an expanding process after dicing the wafer, a large number of objects to be inspected are collected. When performing an appearance inspection to detect whether or not an individual inspection object is a non-defective product, the same inspection object is based on the conditions of the inspection recipe as many times as the type of illumination, angle, and other imaging magnifications change. It is necessary to repeat the inspection several times. By storing the difference value between the measurement angle and the basic angle of each inspection object as the correction angle, the individual inspection will be repeated in the next repeated inspection. The correction angle information stored in the memory is called up and the position and angle of the image are corrected. It can be avoided, there is an advantage that it shortens the appearance inspection time.

  With regard to the appearance inspection method and the apparatus used therefor, which takes a lot of time, the objects to be inspected are increasingly used in the current situation where digitization is attempted in all industrial structures. Therefore, the present invention, which leads to increasing the production efficiency of the appearance inspection process, is also useful for industrial development.

BRIEF DESCRIPTION OF THE DRAWINGS The whole structure schematic diagram explaining embodiment of this invention. The figure explaining extraction of the straight line used as the standard of the 1st inspection object of the present invention. It consists of a basic angle (θ) consisting of a straight line as a reference of the object to be inspected and a straight line from two patterns of the present invention, and a straight line from two patterns of another object to be inspected and a straight line as a reference. The figure explaining measurement angle ((theta) ') and the correction angle (theta-theta') calculated | required from it. The figure explaining the state of the to-be-inspected target object of this invention. The flowchart which shows the flow in the case of test | inspecting the to-be-inspected target object of this invention. The figure explaining the imaging visual field of the external appearance inspection apparatus of this invention.

  The present invention will be described below with reference to the drawings. FIG. 1 is an overall schematic diagram illustrating an embodiment of the present invention. In the appearance inspection apparatus 5, a stage 52 is provided on a frame 51, and the inspection object 1 is placed on the stage 52, an image is captured using an objective lens 53, and an imaging apparatus 54 installed on the upper part of the frame 51 is provided. Use to image. The captured image information is sent to a computer 2 having an arithmetic processing function connected by a cable, and is stored as individual information of the object to be inspected. The computer 2 includes an extraction unit 21, a correction amount calculation unit 22, a position correction / rotation correction unit 23, and an appearance inspection data processing unit 24.

  Next, the inspection object 1 will be described. In order to give concreteness, an example of an object will be used. For example, as shown in FIG. 4A, a schematic diagram of the state of the chip 11 of the wafer 12 in a state where the wafer 12 that has undergone the dicing process is stretched by the expanding process to make the chip 11 easy to handle is shown in FIG.

  In that case, as illustrated in FIG. 4B, the individual chips 11 are positioned so as to be irregularly rotated in the respective partitions. Although not shown, there is also a form called a flat ring by arranging the chips 11 on the film. Even in this case, the chips 11 are similarly positioned in an irregularly rotated manner.

  Next, a series of existing appearance inspection steps will be described with respect to the appearance inspection device 5 and the inspection object 1 using the flowchart of FIG. First, the wafer 12 shown in FIG. 4A is placed on the stage 52 of the appearance inspection apparatus 5. (Step 1).

  First, as the positioning of the wafer 12 on the stage 52, global alignment is performed as described later.

  That is, when the wafer 12 composed of the assembly of the inspection target objects 1 having the form as shown in FIG. 4-a is placed on the stage 52 of the appearance inspection apparatus 5, as shown in FIG. The imaging field of view of the image of the apparatus 5 is the same as that of a normal microscope, and a field 55 image of a circular microscope is obtained. However, the field of view 56 of the imaging device when the imaging screen is imaged by using the imaging screen as electronic data is rectangular. At that time, when imaging is repeated while obtaining the images on the stage 52 of the appearance inspection apparatus 5 in order to sequentially capture the captured images, for example, the imaging is started from the upper first stage left end chip 11 in FIG. Subsequently, imaging proceeds to the right lateral direction.

  Next, when the imaging of the first row is completed, the image of the chip 11 to be inspected sequentially in the left lateral direction is taken down by one step. As described above, when the stage 52 is moved and the captured image of the chip is obtained, the chip 11 as the array of the chips 11 to be inspected 1 moves while the stage moves from the left end to the right end. The wafer 12 needs to be roughly positioned so that the image 11 obtained by the imaging device 54 falls within the field of view 56 of the imaging device.

  In that case, the leftmost and rightmost ones of the chips 11 arranged on the wafer 12 are extracted, and the image obtained by the imaging device 54 is within the range of the field of view 56 of the imaging device 54 while imaging is performed in the horizontal direction. The placement position of the wafer 12 of the appearance inspection apparatus 5 is adjusted by rotating the stage 52 so as to be accommodated. This adjustment is used as a global alignment process, and a new set of objects 1 to be inspected is placed on the wafer 12 so that the chips 11 at both ends of the wafer 12 are within the field of view 56 of the imaging device in the lateral direction of the imaging device 5. “Align position” is performed as a preparatory step before the inspection is started. (Step 2). The operation is performed while the user visually confirms the captured image.

  Next, the reference position adjustment of the inspection object 1 composed of the chips 11 in the wafer 12 is performed. As described above, this is performed in the global alignment process after the arrangement of the chips 11 in the wafer 12 is adjusted so as to be substantially horizontal with one side of the field frame of the captured image.

  That is, as shown in FIG. 2, as shown in FIG. 2, before starting the individual inspection of the inspection target object 1, the chip 11 that is the selected first inspection target object 1 is extracted, A horizontal edge on the captured image and a reference straight edge or pattern in the chip 11 are extracted so that one side of the field frame of the appearance inspection apparatus 5 and the captured image are substantially horizontal, and two points of the left end and the right end are extracted. As the selected first inspection object 1 is selected on the picked-up image by rotating the stage 52 on the straight line obtained by combining “the selected chip 11 at the reference position” (step 3). The operation is also performed while the user visually confirms the captured image.

  Subsequently, using the chip 11 of the first inspection object 1 that is selected and positioned substantially horizontally, two patterns located at the upper left end and the lower right end are extracted from the captured image in the chip. . As shown in FIG. 3A, “slope“ basic angle (θ) ”7 between the straight line that sets and connects the pattern 1 (61) and the pattern 2 (62) to the selected chip 11 and the reference straight line is obtained. " (Step 4).

  “Define inspection recipe conditions based on the situation of the selected chip 11”, which is the inspection object 1 located at the reference position. (Step 5).

  The inspection recipe conditions are established with a number of conditions when imaging and determining whether the chip 11 of the object 1 to be inspected is a non-defective product using the image. Since inspection conditions from many viewpoints must be established, generally a plurality of inspection recipe conditions are established.

  For example, in order to determine whether or not the chip 11 that is the inspection object 1 is a non-defective product from the captured image, as a specific example, it is inspected whether the illumination type is coaxial illumination or oblique illumination. At the time of imaging, a plurality of illuminations are designated, and the appearance inspection is repeatedly performed for each condition (inspection recipe condition).

  Furthermore, as a specific example in which a plurality of inspection conditions are given, there is a magnification by setting a lens at the time of imaging. In order to determine whether or not the chip 11 as the inspection object 1 is a non-defective product from the captured image, a plurality of magnification conditions at the time of imaging are prepared, and the plurality of inspection conditions are added as inspection recipe conditions. As a result, if the number of inspection recipe conditions based on changes in illumination conditions and multiple magnification conditions set by the lens at the time of imaging are formulated, the inspection recipe conditions regarding illumination and the inspection recipe conditions regarding the magnification during imaging Are overlapped, 5 to 8 types of inspection recipe conditions are applied only by the number of illumination conditions × the number of magnification conditions.

  Next, as shown in FIG. 3B, two patterns are continuously extracted from the captured image of the chip 11 of the next object 1 to be inspected, and the coordinate points 1 and 2 set in the pattern 1 (61). The coordinate point 2 is set to (62), and a straight line connecting the points is obtained. Since the chip 11 of the selected first object 1 to be inspected is adjusted to be substantially horizontal with one side of the field frame of the captured image, the coordinates in the two patterns are combined with a straight line, and the straight line And the reference straight line as a “measurement angle (θ ′)” 8. Thereafter, the coordinate point 1 of the pattern 1 (61) and the coordinate point 2 of the pattern 2 (62) are set to all the chips 11, and the inclination “measurement angle (θ ′)” 8 with respect to the reference straight line is obtained. (Step 6).

  Subsequently, the chips 11 as the inspected objects 1 are extracted one after another. Incidentally, since there are about 10,000 chips 11 that are the inspection object 1 per wafer 12, each measurement angle (θ ′) 8 for each chip 11 that is the inspection object 1 is sequentially obtained individually. At the same time, the difference from the basic angle (θ) is obtained as “correction angle (θ−θ ′)” 9 and stored in the computer 2. (Step 7).

  At the same time, alignment is performed using any one of the coordinate point 1 of the pattern 1 (61) and the coordinate point 2 of the pattern 2 (62), and the image is rotationally corrected using the correction angle 9. After performing the position / rotation correction, “the first appearance inspection based on the inspection recipe is performed (step 8).

  Subsequently, after repeating the appearance inspection based on the same inspection recipe conditions and completing the inspection of one wafer 12 (step 9), changing the appearance inspection conditions based on the next inspection recipe conditions, Returning to step 6, the subsequent first appearance inspection is continued.

  There are approximately 10,000 chips 11 as inspection objects 1 on one wafer 12, and there are 5 to 8 inspection conditions for inspection recipes. Is repeated. After all the first appearance inspections are completed, the process proceeds to step 10.

After the appearance inspection is completed for all the chips 11 based on one of the inspection recipe conditions, if “there is a condition for the next inspection recipe”, the appearance inspection of the next condition is performed. (Process 10)
Here, from the second time, using the image of the chip 11 of the inspection object 1 to be inspected, the individual correction angle for each image of each chip 11 of the appearance inspection object is a computer at the time of the first inspection. 2, the “correction angle 9” of the angle to be corrected of the corresponding chip 11 is extracted from the information of the computer 2 to perform angle adjustment, and the coordinate point of the pattern 1 (61) of the corresponding chip 11 1 or the coordinate point 2 of the pattern 2 (62) is used for alignment.

Continuously, the appearance inspection is performed for all the chips 11 based on the second condition of the inspection recipe. (Step 11).
Further, when there is an inspection condition based on the inspection recipe condition of the appearance inspection, all other inspection objects that are attached using the selected first inspection object 1 in the same manner as the second time. For the object 1, the correction angle 9 for each chip 11 stored in the computer 2 is sequentially taken out and the angle of the image is corrected, and the coordinate point 1 of the pattern 1 (61) in the chip 11 and the pattern 2 (62) Alignment is performed using any one of the coordinate points 2, and the appearance inspection is continuously repeated. (Step 11).

  If the conditions of the inspection recipes for all appearance inspections are repeatedly performed on one wafer 12 and completed (step 12), the appearance inspection for the inspection object 1 for one wafer is completed. (Step 13).

  After the inspection of the various conditions of the inspection recipe created in step 5 is completed for one wafer 12, if there is a next wafer 12, the inspection operation from step 1 is repeated. If there is no next wafer 12, the appearance inspection is completed. (Step 14).

  Note that the main types of defects in the inspected inspection object 1 include scratches on the chip, foreign matter, pattern collapse, and the like.

  When the above-described means is used to repeatedly inspect the appearance of the chip 11 that is a large number of objects 1 to be inspected 1 on the wafer 12 based on the inspection recipe, each time the second and subsequent times, one coordinate point is obtained from the captured image. Further, by performing position correction using the stored correction angle for each chip 11, it is possible to shorten the time for all appearance inspection processes of inspection recipe conditions performed for each wafer 12 unit.

The actual results of time reduction when the appearance inspection of the inspection object 1 is actually performed will be described.
A wafer 12 composed of one chip 11 was subjected to an appearance inspection when there were four inspection recipe conditions. Due to the fact that four inspection recipe conditions were established, four appearance inspections were conducted as follows.

1st time: ... bright field imaging, 1x imaging magnification 2nd time: ... dark field imaging, 1x imaging magnification 3rd time ...: bright field imaging, 5x imaging magnification Inspection area change 4th time ...... dark field imaging Imaging Imaging magnification 5 times Inspection area change

Tact time for existing functions 1) Image capture 2) Extraction of coordinate point 1 of pattern 1 6.4 msec
3) Extraction of coordinate point 2 of pattern 2 6.6 msec
4) Correction angle / movement distance calculation 0.004msec
5) Image rotation / movement 2.9msec
6) Appearance inspection 1.5msec
-------------------------------------------------- --------
Total tact time 17.404 msec

Tact time from the second time of the present invention 1) Image capturing 2) Extraction of coordinate point of any pattern 6.4 msec
3) (Not required) ----
4) Correction angle / movement distance calculation 0.004msec
5) Image rotation / movement 2.9msec
6) Appearance inspection 1.5msec
-------------------------------------------------- --------
Total tact time 10.804 msec

Using the tact time, the time for repeatedly performing the conditions of the four appearance inspections was determined.

When implementing the existing technology When implementing the technology of the present invention First inspection time 174.04 sec 174.04 sec
Second inspection time 174.04 sec 108.04 sec
Third inspection time 174.04 sec 108.04 sec
Fourth inspection time 174.04 sec 108.04 sec
------------------------------------
Total tact time 696.16 sec 498.16 sec
(11 minutes 36 seconds 16) (8 minutes 18 seconds 16).

  As a result, the tact time for the appearance inspection of one wafer was reduced by 3 minutes 18 seconds with respect to the repetition of the appearance inspection four times.

  Further, for example, when the appearance inspection is continuously performed on 25 wafers based on the shortening record, the tact time is shortened by about 82 minutes 30 seconds.

  As mentioned above, although embodiment of this invention was described, embodiment disclosed above is an illustration to the last, Comprising: The scope of the present invention is not limited to this embodiment. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims. That is, the structure, shape, size, material, number, etc. of the whole or part of the appearance inspection apparatus can be variously changed in accordance with the spirit of the present invention.

  From the viewpoint of traceability that has been questioned in recent years for many chips of a collection of objects to be inspected typified by wafers on which chips are integrated, the appearance inspection of the individual chips is much industrially important, The quality of the chips and the like is becoming increasingly important.

  Therefore, it is important to devise so that an appearance inspection can be performed efficiently in the field where the number of chips used is increasing. In particular, from the problem of the number of objects to be inspected 1 and from the number of repetitions based on a plurality of condition numbers of the inspection recipe, the appearance inspection is performed within a short time as in the present invention, as in the present invention. This contributes to an improvement in production efficiency in the inspection process.

DESCRIPTION OF SYMBOLS 1 ... Test object 10 ... Straight line 11 ... (semiconductor) chip 12 ... Wafer 2 ... Computer 21 ... Pattern extraction part 22 ... Correction amount calculation part 23 ... Position correction / rotation correction unit 24 ... Appearance inspection data processing unit 5 ... Appearance inspection device 51 ... Frame 52 ... Stage 53 ... Objective lens 54 ... Imaging device 55 ... Field of view 56 of microscope ..Field of view of imaging device 6... Tilt angle 61 of selected chip .. pattern 1
62 .. Pattern 2
7 ... Basic angle (θ)
8 ... Measurement angle (θ ')
9: Correction angle (θ-θ ')

Claims (5)

In the visual inspection method for a large number of objects to be inspected on a wafer,
When a plurality of inspections with different conditions are repeatedly performed on an inspection object on the same wafer, one coordinate obtained in advance for each inspection object, a reference angle obtained from a reference inspection object, and the object An appearance inspection method characterized in that a position correction is performed using a stored correction angle consisting of a difference from a measurement angle obtained from an inspection object, and an appearance inspection of the inspection object is performed. In an appearance inspection method for a large number of objects to be inspected on a wafer, one of the many objects to be inspected is extracted as a first object to be inspected, and the first object to be inspected is inspected. Extracting a reference straight line from the wiring pattern on the object;
Rotationally correcting and leveling the first object to be inspected in a predetermined direction with the inclination of the reference straight line; and
An angle between a direction of a straight line obtained by combining at least two coordinate points obtained from the wiring pattern inside the first inspection object and connecting the at least two coordinate points and the rotation-corrected horizontal straight line Extracting as a basic angle,
A step of setting a plurality of appearance inspection conditions for the object to be inspected;
For all the objects to be inspected other than the first object to be inspected, a straight line is created by combining at least two coordinate points determined from the wiring pattern in the same manner as described above, and the combined linear directions And extracting the difference in angle between the rotation-corrected first straight line of the inspection object as a measurement angle,
Storing a difference between each basic angle and each measurement angle as a correction angle for each object to be inspected;
A step of performing an angle correction on each inspection object to be inspected using information of each stored correction angle, and a position correction using any one of the coordinate points. Appearance inspection method for objects. In the appearance inspection method in which the inspection object is inspected a plurality of times based on a plurality of inspection conditions for the inspection object, in the second and subsequent inspections, at least two locations determined from the wiring pattern inside the inspection object Position correction is performed using one coordinate point obtained from either one of the coordinate points, and the reference angle obtained from the reference inspection object stored for each inspection object and the inspection object An appearance inspection method characterized by performing an appearance inspection after rotationally correcting an image using a correction angle formed by a difference from a measurement angle obtained from an object. In an appearance inspection apparatus for inspecting a large number of inspection objects on a wafer, one of the large number of inspection objects is extracted as a first inspection object, and the first inspection object is Means for extracting a reference straight line from the wiring pattern on the inspection object;
Means for rotationally correcting and leveling the first object to be inspected in a predetermined direction with respect to an inclination of the reference straight line;
An angle between a direction of a straight line obtained by combining at least two coordinate points obtained from the wiring pattern inside the first inspection object and connecting the at least two coordinate points and the rotation-corrected horizontal straight line Means for extracting as a basic angle;
Means for setting a plurality of appearance inspection conditions for an object to be inspected;
For all the objects to be inspected other than the first object to be inspected, a straight line is created by combining at least two coordinate points determined from the wiring pattern in the same manner as described above, and the combined linear directions And a means for extracting a difference in angle between the rotation-corrected first object to be inspected and a horizontal straight line as a measurement angle;
Means for storing a difference between each basic angle and each measurement angle as a correction angle for each object to be inspected;
Means for inspecting each inspected object to be inspected, performing angle correction using information of each stored correction angle, and correcting the position using any one of the plurality of coordinate points Appearance inspection device for objects. In an appearance inspection apparatus that inspects an inspection object multiple times based on a plurality of inspection conditions for the inspection object, at the time of the second and subsequent inspections, at least two locations determined from the wiring pattern inside the inspection object Position correction is performed using one coordinate point obtained from either one of the coordinate points, and the reference angle obtained from the reference inspection object stored for each inspection object and the inspection object An appearance inspection apparatus comprising means for performing an appearance inspection after rotationally correcting an image using a correction angle formed by a difference from a measurement angle obtained from an object.

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