JPS62154116A - Positioning device - Google Patents

Abstract

PURPOSE:To obtain the deflecting information on a member to be detected against a specific position from the 1-dimensional pattern information obtained from a line sensor by means of a simple arithmetic equation. CONSTITUTION:The position information Yn on the Y axis direction of a center axis 4 corresponding to the distance between a specific position 2 set to a reference axis X and the axis 4 of a pattern 1 is defined as Yn=K.(n1+n2)/2, where K shows a coefficient decided by the picture element size, etc. together with n1 and n2 showing the clock count values up to the rise and fall of the pattern 1 on the basis of the position 2 respectively. At the same time, the position information Xn which defines the axis Y in the direction of the axis X where a line sensor 5 crosses the pattern 1 as a reference specific position 6 is also calculated as necessary from Xn=K.(n2-n1)/2.tantheta. Based on these position information, an object mounting stage, etc. can be driven with highly accurate control.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention fixes an object to a mounting table, controls the movement of this mounting table, and moves the object to a predetermined specific position outside of the mounting table with high precision. The present invention also relates to a positioning device for high-speed positioning.

[Conventional technology]

An object to be processed, such as a semiconductor wafer, is
For example, in a cutting machine that cuts into rectangular chips, the workpiece is fixed to a mounting table that can be moved separately in the Y-axis direction and the θ direction. Place the mounting base in the X position so that they are facing each other correctly.
, it is necessary to position the workpiece by driving with high precision in the Y or Z axis direction.

Conventional methods for this purpose include, for example, Japanese Patent Application Laid-Open No. 59-1766.
As described in Publication No. 10, cutting is performed by capturing a two-dimensional image of a region including the position to be cut on the workpiece, and differentiating the image output with respect to the X and Y axis directions of the two-dimensional image. Positioning is performed by detecting the presence of a street formed at the desired location.

Furthermore, in Japanese Patent Publication No. 59-43820, in order to improve the position matching accuracy of a first object having a first identification pattern and a second object having a second identification pattern, each identification pattern is A light image that is optically formed in a heavy manner is projected onto each image sensor that receives light in the X-axis direction and Y-axis direction, and the resulting image signals in the X-axis direction and Y-axis are
Based on the video signal in the axial direction, the relative deviations of the first object and the second object in the X-axis direction and the Y-axis direction are determined, and the two objects are moved relative to each other so that the deviations are eliminated. An alignment device adapted for alignment is shown.

[Problem that the invention seeks to solve]

According to the above-mentioned conventional technology, it is possible to align a predetermined position of a workpiece such as a semiconductor wafer with a blade of a processing tool with relatively high precision. However, since all of the methods described in the above publications process video signals obtained by photoelectrically converting the workpiece into a two-dimensional image, comparisons are made using signal processing to obtain deviation information. This method not only takes a long time, but also has problems such as difficulty in obtaining sufficient position detection accuracy of the workpiece because the resolution is limited due to the detection of a two-dimensional image.

The purpose of the present invention is to solve the problems in the prior art by providing a method that can process position deviation information of an object to be aligned with respect to a predetermined position at a higher speed and with higher resolution than the conventional method. It is an object of the present invention to provide an alignment device that can detect the position of the target object and, therefore, can further improve the alignment accuracy.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a deviation in which the position in the X-Y coordinate axis direction and/or the other axis direction can be detected with respect to the position of at least one coordinate axis of the X-Y coordinates with respect to a predetermined specific position. a mounting table on which an object having a detection pattern is placed; a deviation detection means including a line sensor that generates a detection signal corresponding to a linear image of the pattern in at least one of the X-Y coordinate axis directions; By comparing and calculating the position information based on the specific position from the position detection means and the reference position information based on the known specific position when the object is correctly placed on the mounting table. , comprises an arithmetic/control circuit that calculates the amount of deviation between the object and the specific position in the Y-axis direction and/or the X-axis direction and generates a control signal corresponding to the deviation amount, and the control signal causes the above-mentioned It is characterized by driving and controlling the mounting table.

[Effect]

FIG. 1(A) shows that in this invention, the object to be aligned (
Hereinafter, for convenience, this will be referred to as the "tested member." ) A basic form 1 of the deviation detection pattern (hereinafter referred to as "pattern") formed in advance on the mounting table, and a line sensor as a deviation detection means fixedly provided at a specific position outside the mounting table in response to the displacement of the mounting table. It shows the relationship with 5. In the figure, position 2 of the reference X-axis indicated by the orthogonal coordinate axes of the test member on which the pattern 1 is formed at a predetermined position is a fixed specific position outside the mounting table, and coincides with the O-th bit of the line sensor. The principle operation of the apparatus of the present invention will be explained assuming that the positioning line 6 shown by the broken straight line of the above-mentioned member to be inspected is aligned therewith.

The pattern 1 is formed of a thin film with good reflection efficiency, such as AI, and has a shape in which the Y-axis direction changes in the X-axis direction in an axially symmetrical manner about the central axis 4 (hereinafter abbreviated as bulge). do). With respect to the optical image of this pattern 1, a line sensor 5 such as a COD which is driven by a clock pulse C (see FIG. 2) of a deviation detecting means, for example, is placed in a positional relationship as shown in the figure. A detection signal from the line sensor 5 when the test member is placed on the mounting table is taken out at the cycle of the clock pulse C that drives the line sensor 5. This can be shown in an analog representation as an output waveform diagram as shown in FIG. 1(B). This output waveform corresponds to a straight line figure in the Y-axis direction at the position of line sensor 5 of pattern 1, and corresponds to the pattern width and Y-axis at that position.
It includes axial position information Yn.

That is, the positional information Yn of the central axis 4 in the Y-axis direction corresponding to the distance from the specific position 2 set as the reference X1lllK to the central axis 4 of the pattern 1 can be easily obtained from the following equation (1).

Y n = K・(nl−)n, )/2・・・・・・・
・・・・・・・・・(1) The coefficients are constants obtained from the pixel size of the line sensor and the magnification of the microscope, and 01 and n are constants from the specific position 2 to the rising and falling edges of pattern 1. This is the count value obtained by counting each clock pulse.

Also, by calculating the following equation (2) as necessary,
It is also possible to easily calculate the positional information Xn in which the line sensor 5 uses the Y-axis in the X-axis direction that intersects the pattern 1 as the reference specific position 6.

That is, the position of the illustrated pattern 1 in the Y-axis direction is determined with respect to the fixed specific position outside the mounting table based on the alignment position 6 of the test member indicated by the broken straight line in FIG. 1(A). is formed in a relationship that exactly coincides with the central axis 4 of pattern 1, the fixed specific position outside the mounting table can be determined by calculating the difference between the known distance Yh between them and the calculation result value YnO of equation (1) above. The amount of deviation (Y h - Y n
) can be obtained. Furthermore, if necessary, it is also possible to simultaneously produce the amount of deviation in the X-axis direction with respect to the reference Y-axis 6.

Therefore, if the mounting table is controlled to move in the Y-axis direction and/or X-axis direction according to the amount of deviation so that the amount of deviation becomes zero, the position of the member to be inspected should be aligned. position 6
coincides with the fixed specific position 2 outside the mounting table,
The member to be inspected can be positioned at a predetermined correct position.

Note that each count value n1, n, of the clock pulse corresponding to the position information based on the specific position of each edge of pattern 1 is
As a specific means for obtaining the above, for example, two resettable pulse counters are operated simultaneously and synchronously by the clock pulse for driving the line sensor, and one of them operates as shown in the waveform diagram in FIG. 1(B). The number 01 of clock pulses in the period up to timing t1 at the beginning of the output waveform of the line sensor shown in the diagram is counted separately, and the number 02 of clock pulses in the period up to timing t2 at the end of the same waveform diagram is counted separately. Configure.

The two pulse counters configured in this way are shown in Figure 1 (
The line image in the Y-axis direction at a predetermined known and accurate distance from the specific position 2 of A) to the central axis 4 of the pattern 1 is reset at a timing preceded by the number of lock pulses necessary for the line sensor 5 to sequentially take out line images. make it work like this
For example, each count value n at the timing of tl and t2,
, n2 corresponds to the positional information in the Y-axis direction of the upper and lower edges of pattern 1 shown in FIG.
Alternatively, equation (2) can be calculated.

In this way, the device of this invention detects the deviation information of the member to be inspected with respect to a specific position from the one-dimensional image information obtained from the above-mentioned shaped pattern by the line sensor, and can Since the amount of deviation can be calculated using an arithmetic expression, the amount of deviation can be obtained extremely quickly.

In other words, conventionally, the positioning position is detected using two-dimensional information, so if an image sensor with a pixel count of 512 x 512 is used, for example, all of the pixel information is taken into a processing unit and processed. must,
This will require a considerable amount of calculation processing time. In comparison, this invention uses one-dimensional information obtained by an in-sensor to perform positioning, and it is possible to use an existing line sensor with a pixel count of 2,048 to 4,096. This enables a significant reduction in processing time.

Furthermore, in conventional systems that use two-dimensional information, the total number of pixels is larger compared to systems that use line sensors as in this invention, but when considering line image information, existing line sensors have a large number of pixels. As is clear from the fact that the number of pixels is 2048 or 4096, the line sensor has a larger number of pixels, so its resolution is correspondingly higher. Therefore, with the present invention, not only the processing time is shortened but also the alignment accuracy is further improved.

Conventionally, area sensors used to obtain two-dimensional information have a structure in which a signal line provided for each pixel is placed between pixels, which limits the pixel size, so it is necessary to increase the pixel density. I can't. On the other hand, in the line sensor, the signal line can be drawn out to the left and right of the pixel, so the pixel size can be made smaller and the pixel density can be increased compared to the area sensor.

Incidentally, even if the manufacturing technology improves in the future and the pixel size becomes smaller, the above-mentioned structural difference will not change, so the difference in pixel density will still not be reduced.

〔Example〕

FIG. 2 is a configuration diagram showing an example of an embodiment of the device of the present invention.

In the same figure, reference numeral 21 denotes a mounting table for the member to be tested, which includes a rotary table 22, an X-axis movable table 23 for displacing the rotary table 22 in the Y-axis direction, and an X-axis movable table 26 that is placed on the rotary table 22. and an X-axis movable table 24 for displacement in the X-axis direction, and each of the tables 22, 26, 24 is configured to be driven individually by a drive signal from a drive circuit 25.

The member to be inspected 26 is placed on the rotary table 22 on the mounting table 21.
0 Place and hold in the specified position.

Reference numeral 27 denotes a processing tool drive unit, which in the case of a cutting machine, for example, controls the rotation and vertical direction of a rotary cutting wheel 28, etc.
They are driven by respective drive signals derived from the drive circuit 25. The position of this cutting whetstone 28 corresponds to a specific position outside the mounting table 21. The cutting whetstone 28 is movably controlled in the Z direction by a cutting control signal from the drive circuit 25, and is configured to be able to cut the member to be inspected 26 in the X axis direction.

The specific position is set at a correct position separated by a known distance from a deviation detection means 29, the details of which will be described later, and the deviation detection means 29 is also placed on the rotary table 22. The pattern formed at a predetermined position on the part to be inspected is
It is set correctly in a position where it can be detected reliably.

In this example, it is assumed that the pattern provided on the test member 26 is formed in a form that can be detected optically, for example,
The deviation detection means 29 has a configuration that deals with this.

That is, the deviation detecting means 29 guides the light beam from the light source 60 to the pattern of the test member 26 via the half mirror 61, and projects the microscopic light image of the pattern 1 onto the line sensor 5. It is constructed in one piece. The line sensor 5 is arranged in the relationship explained above with reference to FIG.
It is fixedly provided at a position outside the mounting table 21 so that it is always projected onto the line sensor 5 when it is held on the mounting table 21.

Therefore, for example, if the pattern has the basic shape shown in FIG. 1(A), the detection signal obtained by guiding the output of the line sensor 5 to the sample-hold circuit 62 is as shown in FIG. 1(B). It will be like this.

The output of this sample and hold circuit 32 is digitized via an A/D converter 66 and led to a memory 64, and is placed at a predetermined address position corresponding to the position of the X-Y coordinate axes by an address signal from the arithmetic/control circuit 35. Memorize sequentially.

The arithmetic/control circuit 65 stores the stored values nI, n2 of the addresses necessary for the calculations of equations (1) and (2) in the memory 6.
4, calculate each of these equations, and convert each calculation result value Yn, Xn to each known reference value Yn',
The amount of deviation in the Y-axis direction corresponding to the difference from X n'(Yn'-
Yn) and (Xn'-Xn), and outputs a control signal for correcting these deviations. Furthermore, when a member to be inspected 26 on which a pattern of a shape to be described later is formed is placed on the rotary table 22, the amount of rotational deviation of the member to be inspected 26 can be calculated and a correction control signal thereof can also be output. .

The drive circuit 25 drives the Y-axis movable table 26, the X-axis movable table 24, and the rotary table 22 of the mounting table 21 by directions and distances corresponding to the respective deviation amounts n. When the amount of deviation becomes zero, each control signal also becomes zero, and each part 22, 26, 24 constituting the mounting table 21 stops at a controlled position.

In this state, the specific position of the test member on the mounting table 21, that is, the position to be aligned with the position of the cutting wheel 28, is determined by its fixed position, as explained with reference to FIGS. 1(A) and (B). This means that it is displaced by the movement of the mounting table 21 so as to match the position.

FIG. 3 shows a pattern forming position on a member to be inspected, taking a semiconductor wafer 41 as an example.

Dotted lines 42-1 to 42-(n-·1) indicate positions in the Y-axis direction to be cut, and 43-1 to 43-m indicate, for example, IC chips formed on the wafer 41. .

In this example, the position of the blade edge (28 in FIG. 2) of the cutting wheel fixedly arranged so that the blade edge coincides with the cutting position is defined as a specific position, and the cutting position 42 aligned in the Y-axis direction of the wafer 41 is at this position. -1 to 42-(n-1) are aligned sequentially. For this purpose, each cutting position 42-1 to 42-(
central axes 4 separated by a known distance Yh from n-1)
On the other hand, the wedge-shaped deviation detection patterns 1-1, 1 to 1-n, and 2n, which are axially symmetrical and explained with reference to FIG. With a shape in which the central axis 4 parallel to the line n-1) is a common central axis,
It is formed by an optically readable form.

By using the semiconductor wafer 41 on which the patterns 1-1.1 to l-n-2n are formed as a member to be tested and performing the test according to the configuration of the embodiment shown in FIG. Using one of the five patterns 1-1/1 of the pair of patterns -1Φ1 and 1-1/2, the amount of deviation in the Y-axis direction and the X-axis direction can be determined as described above. Also, each pattern forming a pair, for example 1-
By determining the amount of deviation in the Y-axis direction or the X-axis direction for patterns 1, 1, 1-1, and 2, and comparing them, the rotation angle of the X-Y coordinate axes of the semiconductor wafer on the mounting table 21 can be determined. There is an advantage that the deviation angle of θ can also be easily detected.

In the configuration of the embodiment shown in FIG. 2, the calculation/control circuit 65 calculates such a rotational deviation angle θ, supplies a control signal corresponding to the deviation angle θ to the drive circuit 25, and thereby The deviation angle θ is corrected by controlling the rotation angle of the rotary table 22 of the mounting table 21. Also, the calculation/control circuit 6
5 supplies the drive circuit 25 with a control signal corresponding to the control of the mounting table 21 and the drive of the cutting grindstone 28 in the Z-axis direction with respect to the member to be inspected.

Next, modified examples of the deviation detection pattern of the tested member in this invention are shown in FIGS. 4(A), 5, 6, and 7.
FIG. 8(A) and FIG. 8(A) respectively show n.

It should be noted that each of these modifications is optimal for obtaining the effects of the present invention when applied when the mounting error of the test member on the mounting table 21 is large.

FIG. 4(A) shows a shape in which two wedge-shaped patterns are combined in opposite directions, with a positional relationship diagram of the projected image on the line sensor 5, similar to FIG. 1(A). .

That is, each pattern 44-1, 44-2 has two central axes 45-1.
45-2 are each axially symmetrical in shape, and have wedge shapes in which the inclination angles θ of the inclination portions are equal and the inclination directions are opposite.

By detecting such a pattern with the line sensor 5 in the same way as explained with reference to FIG. 1(A),
A detection output as shown in FIG. 4(B)K can be obtained. As in the case of the rabbit, each count value n obtained by setting the evening and timing clock pulses corresponding to a specific position to 0 bits
By calculating the following equations (3) and (4) using 1 to n4, the Y-axis position Yn and the X-axis corresponding to the number of pulses n corresponding to the center of each pattern 44-1. It is sufficient to calculate the position Xn and find the amount of deviation with respect to the known reference position in the same manner as in the example of the rabbit.

Yn=ni-t(J-)-n2)/2+(ns+
n4 )/2 )2・・・・・・・・・・・・(3) Xn=K −((n2 +n, )/2−n
l/lanθ ... ... ... (4
) The pattern example shown in FIG. 5 is an example formed by four axially symmetrical blows arranged in the Y-axis direction. In this example, the sizes of the four blowing patterns 46-1 to 46-4 in the Y-axis direction are made to be different, and the gaps between the patterns are all formed to be equal. It is possible to calculate not only the amount of deviation of the coordinate axis but also the amount of rotational deviation of the coordinate axes at the same time.

FIG. 6 also shows an example of the shape of a deviation detection pattern that can achieve the same purpose. In this example, the shape has a shape in which draft patterns of equal dimensions are arranged with the same pressure in the Y-axis direction and alternately in opposite directions, with the width of the mutual gap sequentially different,
Similar to the example illustrated in FIG. 5, each deviation amount can be detected with extremely high accuracy.

Figure 7(A) shows a strip pattern parallel to the Y axis and a Y axis.
This is another example of a deviation detection pattern, which is a detection pattern consisting of a band-like pattern inclined with respect to the axis.

A pair of patterns formed by combining an inclined pattern 48-1 having the same width and any one of patterns 48-2 to 48-4 parallel to the Y-axis and having different widths in the Y-axis direction. The strip width of each pattern 48-2 to 48-4 is different from the width of the inclined pattern 48-1.

That is, when the mounting error of the test member on the mounting table is large, one of the three sets of patterns is detected by the line sensor 5 of the deviation detection means set at a predetermined position outside the mounting table. 5, three sets are arranged at appropriate intervals along the Y axis.

The lower patterns 48-2, 48-3, 48-4 of each group have a band-like shape centered on each central axis 49 parallel to the 49, it has a band-like shape centered on each central axis 50 making an angle θ. n patterns in each of these sets, for example, the topmost pair pattern 48-1.48 as shown in the figure.
-2 is detected by the line sensor 5, a detection signal with a waveform as shown in FIG. 7(B) is obtained.

As explained using FIGS. 1(A) and 1(B), by applying the origin pressure to the Y-axis corresponding to a specific position outside the mounting table and counting, clock pulses up to each edge of the detected waveform can be calculated. The count value nl s n2 ,'3,
"4 is obtained. Using this n, the following equation (15) and the following equation (
5), the position Yn/ in the Y-axis direction and the position Xn in the X-axis direction are calculated and aligned.

Yn=K・(nl+n2)/2・・・・・・・・・
・・・・・・・・・(1)
anθ ・・・・・・・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・(5) When preparing multiple sets of patterns like this and detecting any of them, which pattern is the line? sensor 5
It is necessary to identify whether it was detected by The lower pattern width of each of the plurality of pairs of patterns is made different for identification purposes.

That is, the difference between the count values nl and n2 determined from the output of the line sensor 5 corresponds to the width of the detected pattern 48-2 in the Y-axis direction.

Therefore, by calculating the difference and comparing the difference with predetermined known values corresponding to the widths (dimensions of the respective widths), it is possible to easily detect at which position the pattern has been detected. Therefore, according to the detected pattern, the known distance (Y□, Y2, Y,) to the position (Yo) to be aligned with the specific position of the test member indicated by the broken line 6 is determined.
All you have to do is change.

FIG. 8(A) shows a detection pattern which is symmetrical in the Y-axis direction with respect to the central axis 52 and is composed of a band-shaped portion inclined with respect to the Y-axis, and is an example of another deviation detection pattern.

The inclined pattern 51-11 having the same width and the above-mentioned pattern 5i-1i inclined axially symmetrically about the central axis 52.
and pattern 51-12 of the same width are formed on the test member by lining up three sets in the Y-axis direction, and these (51-11, 5l-12), (51-
21, 5l-22) and (51-31, 51-ro2), each of the strips has a different pattern.

That is, when the mounting error of the test member on the mounting table is large, one of the three sets of patterns is captured by the line sensor 5 of the deviation detection means set at a predetermined position pressure outside the mounting table. As shown, three sets are arranged at appropriate intervals along the Y axis.

Upper pattern of each set 51-11.51-21.51-
31 has a band-like shape centered on each central axis 56-1 forming an angle θ with respect to each central axis 52 parallel to the X-axis direction, and the lower patterns 51-12. 51-22
．． 51-32 are axially symmetrical with respect to the upper pattern of each set and each central axis 52, that is, θ with respect to each central axis 52.
It has a band-like shape centered on each central axis 56-2 forming an angle, and the upper central axis 56-1 and the lower central axis 5
6-2 intersect on the axis of symmetry 52.

If any of the patterns in each group, for example, the top pattern (51-11, 5l-12) as shown in the figure, is detected by the line sensor 5, the pattern as shown in FIG. 8(B) is detected. A waveform detection signal is obtained.

As explained using FIGS. 1(A) and 1(B), by counting with the X-axis corresponding to a specific position outside the mounting table as the origin, clocks up to each edge of the detected waveform can be calculated. Pulse count value n1. Get n2, mouth 3, n4. By using this to calculate the following equation surface and the following equation (6), the position Yn in the Y-axis direction and the position Xn in the X-axis direction are calculated and aligned.

Yn=K ((nl +n, )/2+(n5-1-n
4)/2)/2・・・・・・・・・・・・(3), Xn=K ((n, -1-n4)/2-(n, +n
2 /21/2 ・tanθ・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・・・・
(6) When preparing a plurality of such patterns and detecting any one of them, it is necessary to identify which pattern has been detected by the line sensor 5. The widths of the plurality of patterns are made to be different for identification purposes.

That is, the difference between the count values n and n2 calculated from the output of the line sensor 5, or the difference between the count values n and n4, is the Y of the detected pattern 51-11 or 51-12.
It corresponds to the width in the axial direction.

Therefore, by calculating the difference and comparing it with a predetermined known value corresponding to the width (dimensions of each width), it is possible to easily detect in which position the pattern has been detected. .

Therefore, according to the detected pattern, the position (Y
o) by changing the known distances (Yt, Yt, Ys).

Even if the patterns shown in FIG. 1(A), FIG. 5, FIG. 6, FIG. 7(A), and FIG. 8(A) are used, Y
It is possible to obtain the positional accuracy in the axial direction with a fairly high degree of accuracy, but in order to prevent the detection positional accuracy when using diagonal patterns or a small number of patterns, the detection positional accuracy in the Y-axis direction is required to be more accurate. For this purpose, it is desirable to use a plurality of strip patterns parallel to the X axis as the deviation detection pattern.

FIG. 9(A) shows an example for precise positioning. In the illustrated example, three strip patterns 54-1.54-2.54-6 are formed at equal intervals in the Y-axis direction.
This is an example in which the patterns are formed as a set of patterns.

A pattern 54-1.54-2.54-6 for precise alignment is used as a deviation detection pattern as shown in FIG. 9(A).
5, 6, 7 (A) or 8 (
After detecting the amount of deviation using the pattern A) for rough alignment, the mounting table is controlled using this pattern so that the line sensor 5 of the deviation detection means is positioned at the projected position of the pattern for fine alignment. Move the member to be inspected. This results in Figure 9 (
The line sensor 5 reads out a one-dimensional image in the Y-axis direction of the deviation detection pattern for precision alignment shown in A).

In other words, the precision alignment deviation detection pattern indicates that the test member is correctly positioned when the position Yc of the center axis 55 of the three parallel patterns 54-1 to 54-3 is detected as a predetermined value. is formed on the member to be inspected. Then, in a state where the member to be inspected has moved as described above,
It is arranged in a projected relationship with respect to the line sensor 5 as shown in the figure. Usually, it is appropriate to provide two positions on both sides of the member to be tested so that the rotational deviation of the member to be tested can be detected at the same time.

FIG. 9(B) shows the relationship between the output waveform and the counted values 00 to n6 at the edge portion of the output waveform counted based on a specific position outside the mounting table.

By calculating the following equation (7) from each of these count values 01 to n6, the position Yc of the center axis 55 of the extremely accurate and precise positioning deviation detection pattern is determined using the following equation, and this is set as the reference value. Correct alignment can be achieved by displacing the member to be tested so that the amount of deviation as a result of the comparison becomes zero.

Yc==−((n,+n2)+2(n3+n4)+(
n, +n, ) )/s ・・・・・・・・・・・・
...(Force) Also, as mentioned above, if the deviation detection patterns for precise alignment are provided at both ends of the test member in the X-axis direction, and Yc is determined for each pattern and compared. Since the rotation angle deviation of the member to be inspected can be detected accurately and easily, it is possible to correctly align the rotation angle deviation as well.

In addition, in this invention, the shape and structure of the deviation detection pattern of the member to be tested are not limited to those of each of the above embodiments.
Of course, any shape may be used as long as it can obtain displacement information at least in the Y-axis direction of the member to be tested placed on the mounting table.

〔Effect of the invention〕

According to this invention, the deviation information of the member to be inspected is obtained from a one-dimensional image signal obtained using a line sensor having a high resolution of 2,048 to 4,096 pixels. For example, compared to the conventional method of detecting displacement information from a two-dimensional image signal obtained using an image sensor with 512 x 512 pixels,
Since the calculation processing time is significantly reduced, the alignment speed can be further improved.

Further, since the amount of deviation is obtained by processing the image signal obtained by the high resolution of the line sensor, the calculation accuracy of the amount of deviation is high.

Therefore, combined with the shortening of the calculation time, extremely high alignment accuracy can be obtained. Incidentally, according to experimental results, it has been confirmed that the calculation speed is 1/10 or less compared to the conventional method, and the alignment accuracy is increased three to four times.

[Brief explanation of drawings]

FIG. 1(A) is an explanatory diagram of the relationship between the basic form of the deviation information detection pattern formed on the object to be aligned and the line sensor used as the deviation detection means for detecting the pattern in this invention apparatus; FIG. 2B is an explanatory diagram of the output waveform of the 1d alignment line sensor, FIG. Front view of a semiconductor wafer showing an example of the formation and position of a deviation detection pattern to be formed, FIGS. 4(A) and 4(B)
) is an explanatory diagram of another example of the deviation detection pattern and the output waveform of the line sensor in that case, FIG. (B
) is another deviation detection pattern and line sensor output waveform diagram, and Fig. 9 shows the deviation detection pattern of Fig. 5, Fig. 6, Fig. 7 (A) or Fig. 8 (A). It is a pattern diagram suitable for use as a fine positioning pattern when used as a coarse positioning pattern. 1.1-1・1~1-n @n, 44-1~44-
2.46-1~46-4.47-1~47-4.48-
1~48-4.51-11~51-32.54-1~5
4-6...Deflection detection pattern, 2.6...
...Specific position, 3...Position to be aligned with the specific position of the test member, 4.45-1.45-2.49.50.52.53-1
．． 56-2.55... central axis of this pattern, 5... line sensor, 21... n units, 22... rotary table, 26...Y
Axis movable table, 24...X-axis movable table,
25... Drive circuit, 26... Member to be inspected, 27... Process tool drive unit, 28... Cutting wheel, 29... Deviation detection means, 60...
...Light source, 61...Half mirror-162...
...Sample hold circuit, 63...A/
D converter, 34...Memory, 35...
- Arithmetic/control circuit. 41... Semiconductor wafer, 42-1 to 42-(n-1)... Position to be cut, 46-1 to 46-m... IC chip. Patent Applicant: Citizen Watch Co., Ltd. NEC Corporation Fig. 1, fi1 i-stand pattern 2.6. Custom-made Y stand 1 3, Specific stand of pre-skin examination table P hand
I-1'r, Ed22: Rotating Cheer 29: Section NTL General Means 2
3: Ytun 1 town motion table 30: Chuun θ
24: ×axis'qtn cheagle 31: Half mirror-2G Futoko'i2 sword fP Neo 27: Power OT-Guma [etn'ip Fig. 3 1-/-/~/-71・2π: Bilateral gong Otsu Muha 0 goon 4/:'4 conductor wafer 42-/ ~42-(n-1): Off: 1lTl,
yo') and f3 im, 143-1~43-tn-: I
C Natsua Figure 4 Figure 5 @ 6 Figure 7 (B) i Z Figure 8 (A) Figure 8 CB) No. 91 Wildebeest 2 - 65! , 54-3 (B)

Claims (1)

[Claims] A mounting table on which an object having a deviation detection pattern that can detect a position in the direction of the coordinate axis and/or the other axis relative to the position of at least one coordinate axis of the X-Y coordinates with respect to a predetermined specific position; deviation detection means including a line sensor that generates a detection signal corresponding to a linear image in at least one coordinate axis direction of the X-Y coordinates of the pattern;
Comparing and calculating position information based on the specific position from the deviation detection means with reference position information based on the known specific position when the object is correctly placed on the mounting table. Depending on the Y-axis direction or/and
It is characterized by comprising an arithmetic/control circuit that calculates the amount of deviation between the object and the specific position in the axial direction and generates a control signal corresponding to the amount of deviation, and drives and controls the mounting table using the control signal. alignment device.