JP4561291B2 - Exposure method - Google Patents

Description

  The present invention relates to an exposure method used for manufacturing a substrate such as a printed board or a liquid crystal substrate, and more particularly to an exposure method in which a substrate is divided into a plurality of rectangular exposure areas and each exposure area is sequentially exposed.

In a production process of a semiconductor manufacturing apparatus, when a mask pattern formed on a mask is exposed to a wafer as a processing substrate, an exposure area on the wafer is divided into a plurality of areas, and the mask pattern is projected onto the divided area. A method is adopted in which the work stage on which the wafer is placed is moved by a predetermined amount to sequentially move the divided exposure areas to exposure positions and perform exposure in order. This is generally called sequential exposure and step-and-repeat exposure (hereinafter referred to as sequential exposure).
Conventionally, when performing exposure processing in fields other than the above semiconductor manufacturing equipment, for example, in the production of printed circuit boards, liquid crystal substrates, etc., a mask having the same size as the substrate is prepared, and the entire exposure area of the substrate is exposed at once Batch exposure has been performed. However, recently, in order to prevent an increase in the size of the mask accompanying an increase in the size of the substrate, sequential exposure has been adopted also in the above fields.
When the mask becomes large, there are problems such as an increase in mask manufacturing cost and a decrease in exposure accuracy due to the mask's own weight. By employing sequential exposure, the size of the mask can be made smaller than the size of the substrate, so that the above problem can be solved.
An exposure apparatus that sequentially exposes the printed circuit board, the liquid crystal substrate, and the like is disclosed in, for example, Patent Document 1 and Patent Document 2.

In the sequential exposure as described above, when a plurality of identical patterns are formed on one substrate and the substrate is a large substrate such as a printed circuit board, the number of exposures per substrate is reduced. In order to shorten the processing time, a method may be employed in which a plurality of identical patterns are formed side by side so that the mask does not become large, and several masks are exposed together.
FIG. 12 is a schematic block diagram of a conventional sequential exposure apparatus, which will be described with reference to FIG.
The same pattern (indicated by P in the figure) of 2 rows × 2 columns is formed on the mask M, and mask alignment marks (hereinafter referred to as masks) for alignment are formed at the four corners of each pattern of 2 rows × 2 columns. MAM (abbreviated as mark) is formed. Here, the arrangement of the patterns in the horizontal direction of the mask M is referred to as a row, and the arrangement in the vertical direction is referred to as a column.
A substrate (work) W to be exposed is laid out so that the same pattern of 4 rows × 4 columns is formed, and workpiece alignment marks (hereinafter referred to as workpieces) are previously placed at the four corners of each pattern so as to correspond to the mask mark MAM. WAM (abbreviated as mark) is formed.

In exposing the mask pattern P onto the workpiece W, first, the mask M and the workpiece W are aligned.
For this reason, alignment microscopes 2a to 2d for detecting alignment marks are inserted in the exposure region (indicated by dotted lines on the workpiece in the figure). At least two alignment microscopes 2a to 2d are required to align the mask M and the workpiece W in the vertical and horizontal rotation (XYθ) direction. In this example, four units are used, and four alignment microscopes are used to mask masks MAM1, MAM2, MAM3, and MAM4 at the four corners of the 2 rows × 2 columns pattern on the mask M (in the same figure). And the workpiece marks WAM11, WAM12, WAM13, WAM14 (shown by black circles in the figure) at the four corners of the 2 rows × 2 columns pattern on the workpiece W are aligned.
The alignment of the mask M and the work W can theoretically be performed using two mask marks and the corresponding work marks. However, in order to secure the alignment accuracy, as much as possible is possible. It is desirable to use a mark. Here, four mask marks provided at the four corners of the mask M and four work marks corresponding thereto are used.

Images of the mask marks MAM1 to MAM4 and the work marks WAM11 to WAM14 are detected by being received by the image sensors S of the alignment microscopes 2a to 2d, and are subjected to image processing in the image processing unit 11.
The control unit 12 moves the work stage (not shown) on which the work W is placed by the work stage control unit 13 so that the images of the mask marks MAM1 to MAM4 and the work marks WAM11 to WAM14 have a predetermined positional relationship. Move. Note that, instead of moving the workpiece W, the mask M may be moved. However, a case where the workpiece W is moved will be described below.
Thus, the mask marks MAM1 to MAM4 and the work marks WAM11 to WAM14 are aligned so as to have a predetermined positional relationship. Note that this alignment may be performed visually.

When the alignment of the mask M and the workpiece W is completed, the alignment microscopes 2a to 2d are retracted, and the mask M is irradiated with light including exposure light from the light irradiation unit 1 including the lamp 1a and the reflecting mirror 1b. The formed 2 rows × 2 columns of the same pattern P is projected onto an area A1 (an area formed by four pattern areas P1 to P4 surrounded by a thick line on the work W). The same pattern P of 2 rows × 2 columns is exposed together.
When the exposure of the area A1 of the workpiece W is completed, the workpiece W is moved by two rows of the pattern P in the left direction of the drawing, and the exposure of the area A2 of the workpiece W (an area formed by the four pattern areas adjacent to the area A1) is performed. Do.
Also in the exposure of the area A2, the masks MAM1 to MAM4 and the work marks WAM provided at the four corners of the area A2 are detected by the alignment microscopes 2a to 2d in the same manner as the alignment of the area A1. Align the workpiece W. Since the relative positions of the mask marks MAM1 to MAM4 are not changed, the positions of the alignment microscopes 2a to 2d are the same as in the case of the alignment of the region A1.
Next, the mask M is irradiated with light including exposure light from the light irradiation unit 1, and the mask pattern P of 2 rows × 2 columns is exposed to the area A 2 of the workpiece W. This completes the exposure of 2 rows × 4 columns.

Subsequently, the workpiece W is moved upward by two lines of the pattern P in the upward direction of the drawing, and the exposure of the area A3 of the workpiece W is performed. That is, the mask marks MAM1 to MAM4 and the work marks WAM provided at the four corners of the area A3 of the work W are detected and aligned, and the pattern P of 2 rows × 2 columns is exposed in the area A3.
Further, the work W is moved in the right direction of the drawing by two rows of the pattern P, and the area A4 of the work W is exposed. That is, the mask marks MAM1 to MAM4 and the work marks WAM provided at the four corners of the area A4 of the work W are detected and aligned, and the pattern P of 2 rows × 2 columns is exposed in the area A4. In this way, a 4 × 4 pattern is exposed on the workpiece W.
When the pattern P is exposed one by one, the alignment and exposure procedures must be repeated 16 times. Thus, the alignment and exposure procedures are performed by forming the same pattern in 2 rows × 2 columns on the mask. Can be repeated 4 times.
Japanese Patent No. 2904709 Japanese Patent No. 2994991 JP-A-4-326507 JP-A-9-230610

However, in the case of a method in which a plurality of patterns are formed on a mask and exposed together in this way, there may be a surplus due to the layout of the pattern formed on the workpiece. For example, in the case of the above conventional example, as shown in FIG. 13, when the pattern formed in each row of the work is 4 rows × 5 columns, one column at the right end of the drawing is left.
In the case of FIG. 13, the areas A1 to A4 of the workpiece W can be exposed by the same procedure as in the conventional example. However, the remaining area A5 in the fifth column (area shown by hatching in the figure) to be formed on the work W cannot be exposed in the same manner as the areas A1 to A4.
That is, the area A5 has only one pattern. For this reason, there are WAM 51 and WAM 53 corresponding to the mask marks MAM1 and MAM3, but there is no work mark that should correspond to the mask marks MAM2 and MAM4. Therefore, the four alignment marks originally intended for use cannot be used.
Although the alignment can be performed with only two alignment marks, the mask and the workpiece cannot be accurately aligned, and the exposure accuracy of the area A5 is deteriorated.
Since the work marks WAM52 and WAM54 are also formed on the right side of the pattern of the line in the region A5, the work mark and the corresponding mask mark on the mask M (the pattern of the pattern in the first line of the mask M) are formed. If the mask mark formed on the right side is detected by the alignment microscopes 2a to 2d, alignment can be performed.
However, for that purpose, the two alignment microscopes 2c and 2d on the right side of the drawing must be moved to positions where the work marks WAM51 and WAM53 and the corresponding mask marks can be detected, and the alignment microscopes 2a, 2b and 2c, It is necessary to change the relative position of 2d. For this purpose, a new moving mechanism is required, and an operation for that is required, which complicates the structure and control of the apparatus.

As described above, when the number of patterns formed on the workpiece W is not divisible by the number of patterns formed on the mask, when the exposure is performed by aligning the mask and the workpiece for each exposure of each region. In the conventional sequential exposure method, when exposing the surplus exposure area, it is necessary to perform alignment by reducing the number of alignment marks to be used or by changing the position of the alignment microscope. There have been problems such as a decrease in accuracy and a complicated structure, control and operation of the apparatus.
The present invention has been made to solve the above-described problems of the prior art, and a plurality of identical patterns are formed on a mask, and the plurality of identical patterns are formed on a workpiece in a method of sequentially exposing the workpiece. Even if the number of patterns to be divided is not divisible by the number of patterns formed on the mask, alignment is performed using the number of alignment marks originally intended for use without changing the position of the alignment microscope. It is an object to enable exposure.

In order to solve the above-described problems, in the present invention, a mask on which a plurality of identical patterns and mask / alignment marks corresponding to each pattern are formed and a workpiece are moved relative to each other, and the mask is moved relative to one workpiece. When the plurality of the same patterns formed on the substrate are repeatedly exposed, each time the workpiece and the mask are relatively moved, the mask alignment mark and the workpiece alignment mark formed on the workpiece are aligned. Using the alignment microscope fixed at the same position, the following steps (a) and (b) are repeated to expose the mask pattern over the entire area on the workpiece.
(A) After relatively moving the workpiece and the mask, the alignment microscope formed on the mask and the workpiece alignment mark image formed on the workpiece are detected by the alignment microscope to align the mask and the workpiece. A step of exposing the mask pattern onto the workpiece by irradiating the mask with exposure light.
(B) After relatively moving the workpiece and the mask, the alignment microscope formed on the mask and the workpiece / alignment mark image formed on the workpiece are detected by the alignment microscope to align the mask and the workpiece. Performing a step of shielding a part of the pattern formed on the mask from light and irradiating the mask with exposure light to expose the part of the mask pattern on the workpiece.

In the present invention, the following effects can be obtained.
(1) Even if the number of patterns formed on the workpiece is not divisible by the number of patterns formed on the mask, alignment is performed using the number of alignment marks originally intended for use, Can be exposed.
(2) Since the mask and workpiece can be aligned without changing the position of the alignment microscope even when the surplus area is exposed, there is no need to move the alignment microscope during alignment. The configuration and control of the system are not complicated.
(3) If the exposure procedure is appropriately selected, alignment can be performed using a combination of workpiece and alignment marks having the same number of exposures, so that there is no problem that it becomes difficult to detect the workpiece and alignment marks. .

FIG. 1 is a view showing the arrangement of an exposure apparatus according to an embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a light irradiation unit that irradiates exposure light, and includes a lamp 1a that emits light including ultraviolet rays, and a reflecting mirror 1b that collects light from the lamp 1a.
Reference numeral 3 denotes a mask stage, and a mask M is placed on the mask stage 3. A plurality of identical patterns are formed on the mask M as described above, and mask marks for alignment are formed at the four corners of each pattern.
A masking blade 6 for shielding a part of the mask M is provided between the mask M and the light irradiation unit 1 and in the vicinity of the mask M. The masking blade 6 is composed of 2 to 4 light shielding plates, and is controlled by the masking blade control unit 14 and can be moved in the left-right direction and the vertical direction in FIG. Shield against light. In the figure, a masking blade 6 (A, B) moving in the left-right direction in the figure and a masking blade 6 (C) moving in the vertical direction in the figure are shown.
Note that the masking blade is a light shielding member that is inserted into the light incident side of the mask on which the pattern is formed.When a plurality of patterns are formed on the mask, only the necessary pattern is exposed on the workpiece. Generally used in an exposure apparatus.
As prior art using a masking blade, for example, there are a masking blade 22 of Patent Document 3 and a light shielding plate 5 of Patent Document 4.
The light irradiated from the light irradiation unit 1 is irradiated onto the mask M, and the mask pattern provided on the mask M is projected onto the work W on the work stage 5 through the projection lens 4.

An alignment microscope 2 is provided between the projection lens 4 and the workpiece W. The alignment microscope 2 detects the mask mark and the workpiece mark of the workpiece W so that the mask mark and the workpiece mark coincide with each other as described above. The work stage 5 is moved to align the mask M and the work W.
Two to four alignment microscopes 2 are provided and detect mask marks provided at the four corners of the mask M and 2 to 4 work marks on the work W corresponding thereto. The alignment microscope 2 is configured to be retractable in the direction of the arrow in FIG.
The mask mark image and the work mark image received by the image sensor S of the alignment microscope 2 are sent to the image processing unit 11, and the image processing unit 11 detects the positions of the mask mark image and the work mark image. The position data detected by the image processing unit 11 is sent to the control unit 12, and the control unit 12 sets the work mark control unit 13 so that, for example, the positions of the mask mark and the work mark coincide with each other in a predetermined positional relationship. To move the work stage 5.
In addition, when the pattern formed on the mask M is exposed on the workpiece, the control unit 12 moves the workpiece stage 5 according to a preset procedure and drives the masking blade 6 by the masking blade control unit 14 to A part of the plurality of identical patterns formed on M is shielded from light.

FIG. 2 is a diagram illustrating a configuration example of a moving mechanism of the masking blade 6. FIG. 4A shows the masking blade 6 and the mask M viewed from the light irradiation unit 1 side, and FIG. 4B shows the masking blade 6 and the mask M and mask stage 3 viewed from the direction parallel to the mask surface. Is shown.
In FIG. 2, only two masking blades A and B are shown for the sake of clarity, but when four masking blades are used, another set of those shown in FIG. Prepare it, rotate it 90 ° and place it overlaid.
As shown in FIG. 2, a moving element 21a that moves along the guide 21 is attached to one end of the masking blades A and B, and the masking blades A and B can move along the guide 21 in the direction of the arrow in FIG. It is configured.
By providing the guide 21 with a drive mechanism such as a linear motor, the masking blades A and B can be moved along the guide 21 and positioned at any position on the mask M.

FIG. 3 is a view showing an arrangement example of the masking blade 6. FIG. 3 (a) shows a case where two masking blades A and B moving in the X direction and two masking blades C and D moving in the Y direction are provided. By disposing, the pattern formed on the mask M can be shielded from the horizontal direction and the vertical direction in FIG.
FIG. 3B shows a case where one masking blade A moving in the X direction and one masking blade C moving in the Y direction are provided. By arranging the masking blades in this way, FIG. The pattern formed on the mask M can be shielded from the left direction and the upward direction in FIG.
FIG. 3 (c) shows a case where one masking blade A moving in the X direction and one masking blade C moving in the Y direction are provided, as in FIG. 3 (b). The pattern on the mask M is shielded from light using the edges a1 and a2 of the masking blade A and the edges c1 and c2 of the masking blade C.
For example, by positioning the masking blade A at the position M1, the pattern on the mask M can be shielded from the left side of the figure by the edge a1, and by positioning at the position M2, the pattern on the mask M by the edge a2. The pattern can be shielded from the left side of the figure. Similarly, by positioning the masking blade C at the position M1, the pattern on the mask M can be shielded from the upper side of the figure by the edge c1, and by positioning at the position M2, the pattern on the mask M can be blocked by the edge c2. This pattern can be shielded from the lower side of the figure.

FIG. 4 is a diagram showing a pattern arrangement on the mask M and an exposure area on the workpiece W according to the first embodiment of the present invention, and FIG. 5 is a diagram for explaining alignment when the mask pattern is exposed on the workpiece. . As shown in FIG. 4A, a total of nine patterns P of 3 rows × 3 columns are formed on the mask M, and mask marks MAM are provided at the four corners of each pattern.
The mask pattern P is exposed on the work W, and the work W is laid out so that a total of 35 patterns of 7 rows × 5 columns are formed as shown in FIG. Note that workpiece marks WAM are formed on the workpiece W at positions corresponding to the four corners of each pattern in advance or by previous exposure.
By exposing the workpiece W with several types of mask patterns as many times as necessary, and after the exposure is completed, the workpiece W is cut into each pattern to obtain the product shown in FIG.

As described above, the mask M and the workpiece W are aligned by the mask marks MAM (indicated by the black circles in the figure) marked at the four corners of the mask M and the corresponding workpiece marks WAM ( (Shown by black circles in the figure).
As shown in FIG. 5, four alignment microscopes 2a to 2d are inserted between the mask M and the workpiece W, the positions of the mask mark image and the workpiece mark image indicated by the black circles are detected, and the mask mark and the workpiece are detected. The workpiece W is moved so that the mark positions match.
When the alignment is completed, the mask pattern is exposed on the workpiece W by irradiating light from the light irradiation unit 1 as described above. At that time, a predetermined pattern on the mask M is shielded by the masking blade 6 as necessary.
When the exposure of the area is completed, the work W is moved and the next area on the work W is aligned in the same manner as described above, and a predetermined pattern on the mask M is formed by the masking blade 6 as necessary. The mask pattern is exposed on the workpiece W while being shielded from light. Thereafter, by repeating this operation, a pattern of 7 rows × 5 columns is exposed on the workpiece W.

Next, an exposure procedure (1) on the workpiece of the mask pattern shown in FIG. 4 will be described with reference to FIG. In this exposure procedure, as shown in FIG. 3 (a), four masking blades are used, and a pattern of a necessary portion on the mask M is shielded by the four masking blades. Yes.
In the following, each area where each pattern P on the workpiece W is exposed is referred to as a pattern area, and each pattern area is specified by the row and column numbers attached to the upper side and the left side of the workpiece W shown in FIG. For example, the pattern area of the first row and the first column at the upper left corner is P11, the pattern area of the first and second columns is P12, the pattern area of the second and first columns is P21, and so on. The pattern region in the −5th column is referred to as P75.

(A) As shown in FIG. 6A, the pattern P formed on the mask M is first exposed to the pattern areas P11 to P32 on the workpiece W.
Therefore, the mask mark MAM (mask marks indicated by black circles in FIG. 4) provided at the four corners of the mask M and the workpiece mark WAM formed at the corresponding position on the workpiece W without inserting the masking blade 6. (In this case, the upper left corner of the pattern area P11 of the workpiece W, the lower left corner of the pattern area P31, the upper right corner of the pattern area P13, and the lower right corner of the pattern area P33) are detected by the alignment microscopes 2a to 2d and masked. Align M and workpiece W. At this time, exposure light is not irradiated from the light irradiation unit 1.
Next, as shown in FIG. 6A, the mask M is formed on the mask M by the masking blade B of FIG. 3A so that the pattern areas P13, P23, and P33 of the workpiece W are not irradiated with light through the mask M. A part of the formed pattern is shielded and light is irradiated from the light irradiation unit 1 to expose the pattern areas P11, P12, P21, P22, P31, and P32 of the workpiece W.

(B) As shown in FIG. 6B, the work W is moved to the left by two rows of the pattern P in the figure. Similarly to the above, mask marks MAM (mask marks indicated by black circles in FIG. 4) provided at the four corners of the mask M and work marks formed in corresponding positions on the work W (in this case, the work W The alignment microscopes 2a to 2d) detect the upper left corner of the pattern region P13, the lower left corner of the pattern region P33, the upper right corner of the pattern region P15, and the lower right corner of the pattern region P35, and align the mask M and the workpiece W. Do.
Next, as shown in FIG. 6 (b), light is irradiated from the light irradiation unit 1 without being shielded by the masking blades A to D, and pattern areas P13 to P15, P23 to P25, P33 to the workpiece W are irradiated. P35 is exposed.
Here, since the pattern areas P13, P23, and P33 are shielded from light by the masking blade during the exposure of (a), the pattern areas are not exposed twice.

Further, since the pattern areas P13, P23, and P33 are not exposed at the time of exposure in (a), the workpieces at the upper left corner of the pattern area P13 and the lower left corner of the pattern area P33 that were formed before the exposure in (a). Using the mark and the work mark at the upper right corner of the pattern area P15 and the lower right corner of the pattern area P35, alignment during exposure in (b) can be performed.
The resist changes color when exposed, and the appearance of the work mark with the alignment microscope changes before and after exposure. It becomes more difficult when using a set of marks.
As in (a) above, first, the masking blade is used to expose the pattern areas P13, P23, and P33 of the workpiece W so as not to be irradiated with light through the mask M, and then in (b), the exposure is performed in (a). By performing alignment using the work marks in the pattern areas P13 and P33 that have not been performed and the work marks in the pattern areas P15 and P35 that are to be exposed in the future, a set of work marks having different numbers of exposures as described above can be obtained. Problems due to use can be avoided.

(C) As shown in FIG. 6C, the work W is moved upward by three lines of the pattern P in the figure. Similarly to the above, the mask marks MAM provided at the four corners of the mask M and the work marks WAM formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the mask M and the workpiece W are aligned. I do.
Next, as shown in FIG. 6C, a part of the mask pattern P is shielded by the masking blades A and D, and light is irradiated from the light irradiation unit 1 so that the pattern areas P44 and P45 of the workpiece W are formed. Exposure.
(D) As shown in FIG. 6D, the workpiece W is moved in the right direction by two rows of the pattern P in the drawing. Similarly to the above, the mask marks MAM provided at the four corners of the mask M and the work marks WAM formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the mask M and the workpiece W are aligned. I do.
Next, as shown in FIG. 6 (d), a part of the mask pattern P is shielded by the masking blade D, and light is irradiated from the light irradiation unit 1, so that the pattern regions P41, P42, and P43 of the workpiece W are formed. Exposure.

(E) As shown in FIG. 6 (e), the workpiece W is moved upward by one line of the pattern P in the figure. Similarly to the above, the mask marks MAM provided at the four corners of the mask M and the work marks WAM formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the mask M and the workpiece W are aligned. I do.
Next, as shown in FIG. 6 (e), a part of the mask pattern P is shielded by the masking blade B, and light is irradiated from the light irradiation unit 1, so that pattern areas P51, P52, P61, P62, P71, and P72 are exposed.
(F) As shown in FIG. 6 (f), the work W is moved in the left direction by two columns of the pattern P in the figure. Similarly to the above, the mask marks MAM provided at the four corners of the mask M and the work marks formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the alignment of the mask M and the workpiece W is performed. Do.
Next, as shown in FIG. 6 (f), light is irradiated from the light irradiation unit 1 without shielding with a masking blade, and the remaining pattern areas P53, P54, P55, P63, P64, P65, P73, P74 and P75 are exposed. This completes the exposure of all areas.
In the above description, the case where the four masking blades shown in FIG. 3A are used to shield the light has been described. However, the two masking blades shown in FIG. You may make it light-shield using.

Next, the exposure procedure (2) on the workpiece of the mask pattern shown in FIG. 4 will be described with reference to FIG. In this exposure procedure, as shown in FIG. 3B, two masking blades are used (in this example, two masking blades B and D are used), and a pattern of a necessary portion on the mask M is shielded from light. The procedure for exposure is shown.
(A) As shown in FIG. 7A, the pattern P formed on the mask M is first exposed to the pattern areas P11 to P32 on the workpiece W.
That is, similarly to the exposure procedure (1), the mask marks MAM provided at the four corners of the mask M and the work marks WAM formed at the corresponding positions on the work W are detected by the alignment microscopes 2a to 2d, and the masks are detected. Align M and workpiece W.
Next, as shown in FIG. 7A, a part of the pattern formed on the mask M by the masking blade B so that the pattern areas P13, P23, and P33 of the workpiece W are not irradiated with light through the mask M. Is exposed to light from the light irradiation unit 1 to expose the pattern regions P11, P12, P21, P22, P31, and P32 of the workpiece W.

(B) As shown in FIG. 7B, the workpiece W is moved in the left direction by two columns of the pattern P in the drawing. Similarly to the above, the mask marks MAM provided at the four corners of the mask M and the work marks WAM formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the mask M and the workpiece W are aligned. I do.
Next, as shown in FIG.7 (b), light is irradiated from the light irradiation part 1 without light-shielding with masking blade AD, and the pattern area | regions P13-P15, P23-P25, P33- of the workpiece | work W are irradiated. P35 is exposed. The procedure so far is the same as the exposure procedure (1).
(C) As shown in FIG. 7C, the work W is moved upward by three rows of the pattern P in the figure, and further moved by two columns to the right. Similarly to the above, the mask marks MAM provided at the four corners of the mask M and the work marks formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the alignment of the mask M and the workpiece W is performed. Do.
Next, as shown in FIG. 7C, a part of the mask pattern P is shielded by the masking blades B and D, and light is irradiated from the light irradiation unit 1 so that the pattern areas P41 and P42 of the workpiece W are formed. Exposure.

(D) As shown in FIG. 7 (d), the workpiece W is moved in the left direction by two columns of the pattern P in the figure. Similarly to the above, the mask marks MAM provided at the four corners of the mask M and the work marks formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the alignment of the mask M and the workpiece W is performed. Do.
Next, as shown in FIG. 7 (d), a part of the mask pattern P is shielded by the masking blade D, and light is irradiated from the light irradiation unit 1, so that the pattern areas P43, P44, and P45 of the workpiece W are formed. Exposure.
(E) As shown in FIG. 7 (e), the workpiece W is moved upward by one line of the pattern P and further moved by two columns in the right direction. Similarly to the above, the mask marks MAM provided at the four corners of the mask M and the work marks formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the alignment of the mask M and the workpiece W is performed. Do.
Next, as shown in FIG. 7E, a part of the mask pattern P is shielded by the masking blade B, and light is irradiated from the light irradiation unit 1 so that the pattern regions P51, P52, P61, P62, P71, and P72 are exposed.

(F) As shown in FIG. 7 (f), the work W is moved to the left in the figure by two columns of the pattern P. Similarly to the above, the mask marks MAM provided at the four corners of the mask M and the work marks formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the alignment of the mask M and the workpiece W is performed. Do.
Next, as shown in FIG. 7 (f), light is irradiated from the light irradiation unit 1 without shielding with a masking blade, and the remaining pattern areas P53, P54, P55, P63, P64, P65, P73, P74 and P75 are exposed.
This completes the exposure of all areas.
According to the exposure procedure (2), the amount of movement of the workpiece W when moving to the next area is larger than in the exposure procedure (1), but the exposure can be performed using two masking blades. it can. Further, as in the exposure procedure (1), alignment can be performed using work marks having the same number of exposures.

In the above-described exposure procedures (1) and (2), the case where alignment is performed using work marks having the same number of exposures has been described. If there is no hindrance in alignment, alignment can be performed using work marks having different numbers of exposures.
Next, with reference to FIG. 8, the exposure using the work marks having different numbers of exposures as described above will be described. This exposure procedure shows the procedure for exposure using two masking blades (in this example, two masking blades A and C are used) as shown in FIG. 3B. Yes.
(A) As shown in FIG. 8A, the pattern P formed on the mask M is first exposed to the pattern areas P11 to P33 on the workpiece W.
That is, as described above, the mask marks MAM provided at the four corners of the mask M and the work marks formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the mask M and the workpiece W are aligned. I do.
Next, as shown in FIG. 8 (a), light is irradiated from the light irradiation unit 1 without being shielded by the masking blades A and C, and the pattern regions P11, P12, P13, P21, P22, P23, P31, P32, and P33 are exposed.

(B) As shown in FIG. 8B, the work W is moved to the left by two rows of the pattern P in the figure. Similarly to the above, the mask marks MAM provided at the four corners of the mask M and the work marks formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the alignment of the mask M and the workpiece W is performed. Do.
Here, since the pattern areas P13, P23, and P33 of the workpiece W are already exposed in the above (a), the workpiece mark at the upper left corner of the pattern area P13, the workpiece mark at the lower left corner of the pattern area P33, and the pattern area P15 of the workpiece W. The work mark in the upper right corner and the work mark in the lower right corner of the pattern area P35 have different numbers of exposures, but here, the work marks with different numbers of exposures are used for alignment, assuming that there is no problem in alignment. .
Next, as shown in FIG. 8B, a part of the pattern formed on the mask M by the masking blade A so that the pattern areas P13, P23, and P33 of the workpiece W are not irradiated with light through the mask M. Is exposed to light from the light irradiation unit 1 to expose the pattern regions P14 to P15, P24 to P25, and P34 to P35 of the workpiece W.
(C) As shown in FIG. 8C, the work W is moved upward by three rows of the pattern P in the figure, and further moved by two columns in the right direction. Similarly to the above, the mask marks MAM provided at the four corners of the mask M and the work marks formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the alignment of the mask M and the workpiece W is performed. Do.
Next, as shown in FIG. 8C, light is irradiated from the light irradiation unit 1 without being shielded by the masking blades A and C, and the pattern regions P41 to P43, P51 to P53, and P61 of the workpiece W are irradiated. P63 is exposed.

(D) As shown in FIG. 8D, the workpiece W is moved in the left direction by two columns of the pattern P in the figure. Similarly to the above, the mask marks MAM provided at the four corners of the mask M and the work marks formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the alignment of the mask M and the workpiece W is performed. Do.
Next, as shown in FIG. 8D, a part of the mask pattern P is shielded by the masking blade A, and light is irradiated from the light irradiating unit 1, so that pattern areas P44, P45, P54, P55, P64, and P65 are exposed.
(E) As shown in FIG. 8 (e), the work W is moved upward by one line of the pattern P and further moved by two columns in the right direction. Similarly to the above, the mask marks MAM provided at the four corners of the mask M and the work marks formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the alignment of the mask M and the workpiece W is performed. Do.
Next, as shown in FIG. 8E, a part of the mask pattern P is shielded by the masking blade C, and light is irradiated from the light irradiation unit 1 so that the pattern areas P71, P72, and P73 of the workpiece W are formed. Exposure.

(F) As shown in FIG. 8 (f), the work W is moved to the left in the figure by two columns of the pattern P. Similarly to the above, the mask marks MAM provided at the four corners of the mask M and the work marks formed at corresponding positions on the workpiece W are detected by the alignment microscopes 2a to 2d, and the alignment of the mask M and the workpiece W is performed. Do.
Next, as shown in FIG. 8F, a part of the mask pattern P is shielded by the masking blade C, and light is irradiated from the light irradiation unit 1 to expose the pattern regions P74 and P75 of the workpiece W. . This completes the exposure of all areas.
In the above exposure procedure (3), even if a work mark has a different number of exposures, the alignment is performed using a combination of work marks having a different number of exposures. Can be freely selected as compared with the exposure procedures (1) and (2).

FIG. 9 is a schematic block diagram of a sequential exposure apparatus according to the second embodiment of the present invention.
Two rows of the same pattern P are formed on the mask M of this embodiment, and mask marks MAM1 and MAM2 and MAM3 and MAM4 for alignment are formed on both sides of each pattern P of the two rows. .
In addition, the work W to be exposed is laid out so that the same pattern of 2 rows × 5 columns (there is one remaining column) is formed, and the work marks WAM1 and the work marks WAM1 in advance so as to correspond to the mask marks MAM1 and MAM2. WAM2, WAM3, WAM4... Are formed.
When the mask pattern P is exposed on the workpiece W, the mask M and the workpiece W are aligned as described above.
Alignment microscopes 2a and 2b for detecting a mask mark and a work mark are inserted in the exposure region, and mask marks MAM1 and MAM4 (shown by black circles in the figure) formed on both sides of the mask M by the alignment microscopes 2a and 2b. The images of the work marks WAM1, WAM4 (shown by black circles in the figure) formed on the work W corresponding to the mask marks MAM1, MAM4 are received by the image sensors S of the alignment microscopes 2a, 2b. The In FIG. 9, the projection lens shown in FIG. 1 is omitted.
The received mask mark image and work mark image are sent to the image processing unit 11, and the image processing unit 11 detects the positions of the mask mark image and the work mark image. The position data detected by the image processing unit 11 is sent to the control unit 12, and the control unit 12 drives a work stage (not shown) by the work stage control unit 13 so that the positions of the mask mark and the work mark coincide. Then, the workpiece W is moved.

When the alignment of the mask and the workpiece is completed, the alignment microscopes 2a and 2b are retracted, the light irradiation unit 1 is irradiated with light including exposure light from the light irradiation unit 1, and two rows of the same pattern P formed on the mask M are obtained. Projected onto the workpiece W, the two patterns P formed on the mask M are exposed together on the workpiece W.
When the pattern formed on the mask M is exposed on the workpiece W, the control unit 12 moves the workpiece W according to a preset procedure, and the masking blade control unit 14 moves the masking blades 6a and 6b as necessary. By driving, one of the two identical patterns P formed on the mask M is shielded from light.
Similarly, the above procedure is repeated while moving the workpiece W to the next area, and the pattern P of the mask M is exposed on the workpiece W.

FIG. 10 is a diagram showing the exposure procedure (1) of this embodiment. The exposure procedure of this embodiment will be described with reference to FIG. In this exposure procedure, only the masking blade 6b is used out of the two masking blades 6a and 6b.
(A) The mask marks MAM1 and MAM4 formed on both sides of the mask M and the work marks WAM1 and WAM4 on the workpiece W are detected by the alignment microscopes 2a and 2b, and the mask M and the workpiece W are aligned.
Then, light is irradiated from the light irradiation unit 1, and the same two patterns P formed on the mask M are simultaneously applied onto the workpiece W as shown in FIG. To expose.

(B) As shown in FIG. 10 (b), the work W is moved to the left by two rows of the pattern P in the figure. Mask mark MAM1 and workpiece mark WAM5, mask mark MAM4 and workpiece mark WAM8 are detected by alignment microscopes 2a and 2b, and alignment of mask M and workpiece W is performed.
Next, as shown in FIG. 10B, a masking blade 6b is inserted, the mask pattern corresponding to the pattern area P4 on the workpiece W is shielded from light, and only the pattern area P13 on the workpiece is exposed.
(C) As shown in FIG. 10 (c), the work is moved leftward by one column of the pattern P in the figure. Mask mark MAM1 and work mark WAM7, mask mark MAM4 and work mark WAM10 are detected by alignment microscopes 2a and 2b, and mask M and work W are aligned. Then, the pattern areas P14 and P15 on the workpiece W are exposed as shown in FIG.
Here, at the time of exposure of (b), since the pattern area P4 is shielded by the masking blade, the pattern area P14 is not exposed twice.
In (b), the masking blade 6b shields the pattern area P14 of the work W from being irradiated with light, and then the work mark WAM7 in the pattern area P14 not exposed in (c) and the pattern to be exposed in the future. Since the alignment is performed using the work mark WAM10 of P15 which is an area, the alignment can be performed using a set of work marks having the same number of exposures.
This completes the exposure of the pattern in the first row and the fifth column.

(D) Subsequently, the pattern of the second row is exposed.
First, as shown in FIG. 10D, the work W is moved upward by one line of the pattern P in the figure. Then, as shown in FIG. 10D, alignment and exposure of the pattern areas P21 and P22 on the workpiece W are performed in the same manner as the exposure of the first row.
Next, as shown in FIG. 10E, the work W is moved leftward by one line, the pattern areas P23 and P24 on the work W are aligned, and the pattern area P24 is not exposed by the masking blade 6b. Thus, only the pattern region P23 that is shielded from light is exposed.
Further, as shown in FIG. 10E, the workpiece W is moved leftward by one column, the pattern regions P24 and P25 on the workpiece W are aligned, and the pattern regions P24 and P25 are exposed.
Thus, ten patterns P are exposed on the workpiece W.

According to the above exposure procedure, alignment can be performed using a set of work marks with the same number of exposures, but even with work marks with different numbers of exposures, the appearance by the alignment microscope does not change much, If there is no problem in alignment, alignment can be performed using work marks having different numbers of exposures as shown in the following exposure procedure.
Next, with reference to FIG. 11, the exposure procedure (2) using the work marks having different exposure times as described above will be described. In this exposure procedure, only the masking blade 2a is used.
(A) The mask marks MAM1 and MAM4 formed on both sides of the mask M and the work marks WAM1 and WAM4 on the workpiece W are detected by the alignment microscopes 2a and 2b, and the mask M and the workpiece W are aligned.
Then, light is irradiated from the light irradiation unit 1 to simultaneously expose the same two patterns P formed on the mask M on the work W as shown in FIG.

(B) As shown in FIG. 11B, the workpiece W is moved to the left by two rows of the pattern P in the figure. Mask mark MAM1 and workpiece mark WAM5, mask mark MAM4 and workpiece mark WAM8 are detected by alignment microscopes 2a and 2b, and alignment of mask M and workpiece W is performed.
Then, the pattern areas P13 and P14 on the workpiece W are exposed as shown in FIG.
(C) As shown in FIG. 11 (c), the workpiece W is moved to the left by one column of the pattern P in the figure. Mask mark MAM1 and work mark WAM7, mask mark MAM4 and work mark WAM10 are detected by alignment microscopes 2a and 2b, and mask M and work W are aligned.
Next, as shown in FIG. 11C, the mask pattern corresponding to the pattern area P14 on the workpiece W is shielded by the masking blade 6a, and only the pattern area P15 on the workpiece is exposed.
Here, at the time of exposure of (c), since the pattern area P14 is shielded from light by the masking blade, the pattern area P14 is not exposed twice.
In addition, since the pattern area P14 of the workpiece W has been exposed in (b) above, the number of exposures differs between the work mark WAM7 on the left side of the pattern area P14 and the work mark WAM10 on the right side of the pattern area P15. Assuming that there is no problem in alignment, alignment is performed using work marks having different numbers of exposures.
This completes the exposure of the pattern in the first row and the fifth column.
(D) Subsequently, the pattern of the second row is exposed in the same manner as described above, but the description is omitted because it is similar to the above.

It is a figure which shows the structure of the exposure apparatus of the Example of this invention. It is a figure which shows the structural example of the moving mechanism of a masking blade. It is a figure which shows the example of arrangement | positioning of a masking blade. It is a figure which shows the pattern arrangement | positioning on the mask of 1st Example of this invention, and the exposure area | region on a workpiece | work. It is a figure explaining position alignment of a mask and a work of the 1st example. It is a figure which shows the exposure procedure (1) of a 1st Example. It is a figure which shows the exposure procedure (2) of a 1st Example. It is a figure which shows the exposure procedure (3) of a 1st Example. It is a schematic block diagram of the 2nd Example of this invention. It is a figure which shows the exposure procedure (1) of a 2nd Example. It is a figure which shows the exposure procedure (2) of a 2nd Example. It is a figure which shows a prior art example (1). It is a figure which shows a prior art example (2).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light irradiation part 1a Lamp 1b Reflector 2a-2d Alignment microscope 3 Mask stage 4 Projection lens 5 Work stage 6, 6a, 6b Masking blade 11 Image processing part 12 Control part 13 Work stage control part 14 Masking blade control part
M Mask W Work

Claims (1)

A plurality of identical patterns and mask alignment marks corresponding to each pattern are formed on the mask, and a workpiece alignment is formed on the work corresponding to each pattern formed on the work. In the exposure method of projecting a plurality of the same patterns repeatedly by projecting the mask pattern provided on the mask by irradiating light to the mask from the light irradiation unit, projecting the mask pattern on the workpiece ,
Each time the workpiece and the mask are moved relative to each other, the alignment of the mask alignment mark and the workpiece alignment mark formed on the workpiece is performed using an alignment microscope fixed at the same position. And (b) is repeated to expose the mask pattern over the entire area of the workpiece .
(A) After relatively moving the workpiece and the mask, the alignment microscope formed on the mask and the workpiece alignment mark image formed on the workpiece are detected by the alignment microscope to align the mask and the workpiece. A step of exposing the mask pattern onto the workpiece by irradiating the mask with exposure light.
(B) After relatively moving the workpiece and the mask, the alignment microscope formed on the mask and the workpiece / alignment mark image formed on the workpiece are detected by the alignment microscope to align the mask and the workpiece. Performing a step of shielding a part of the pattern formed on the mask from light and irradiating the mask with exposure light to expose the part of the mask pattern on the workpiece.

Images