JPH0132044Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to the structure of a photomask used when transferring a pattern such as a predetermined light-transmitting film pattern to a transfer plate, and is particularly applicable to reduction projection exposure. When attaching a pellicle to a photomask that transfers a pattern formed on the main surface of the photomask to a transfer plate using a device, etc., a photomask that makes it easy to attach the pellicle and confirms the accuracy of the attachment. Regarding structure.

[Conventional technology]

Conventionally, the structure of a photomask 1 is as shown in FIG.
A device in which a light-shielding film pattern 3 such as a Cr film is formed is known. Furthermore, when transferring the light-shielding film pattern 3 formed on the main surface of the photomask 1 to a transfer plate (not shown) using a reduction projection exposure device or the like, a photomask mounting stage (described later) is provided. A cross-shaped alignment mark 4 and a linear alignment mark 5 for placing the photomask 1 at a predetermined position of the photomask 6 are also formed on the main surface of the photomask 1.

The photomask 1 described above is placed on a photomask placement stage 6 (see FIG. 15) of a reduction projection exposure apparatus, etc., but at this time, the photomask 1 must be placed securely at a predetermined position on the stage 6. . Therefore, in order to ensure the alignment between the photomask 1 and the stage 6, the stage 6 is
A stage mark 7 corresponding to the cross-shaped alignment mark 4 and a stage mark 8 corresponding to the linear alignment mark 5 are formed. Then, as shown in FIG. 16, the cross-shaped alignment mark 4 and the stage mark 7, and the linear alignment mark 5 and the stage mark 8 are accurately matched, respectively, and the photomask 1 is placed on the stage 6.
Place it on.

Incidentally, in recent years, dust has become attached to the main surface of the photomask 1, and in order to prevent the image caused by the attached dust from being transferred to the transfer plate together with the light-shielding film pattern 3, as shown in FIG. , a pellicle 10 is attached to the main surface of the photomask 1. Note that in FIG. 17, illustration of the light-shielding film pattern 3 on the main surface of the photomask 1 is omitted. The pellicle 10 consists of a translucent film 11 made of nitrocellulose or the like and an outer frame 12 that supports the translucent film 11. As shown in FIG. It is arranged at a predetermined distance from the surface via the outer frame 12.

When attaching the pellicle 10 to the photomask 1, a pellicle attaching operator, for example, attaches the pellicle 10 to the photomask 1.
0 on the main surface of the transparent film 11,
The pellicle 10 is attached to the pellicle attachment part 9 so that the center point on the main surface of the photomask 1 corresponds to the center point on the main surface of the photomask 1.
(See Figure 14).

[Problem that the invention attempts to solve]

When placing the photomask 1 with the pellicle 10 attached on the stage 6, as shown in FIG.
a, and the cross-shaped alignment mark 4 and the stage mark 7, and the linear alignment mark 5 and the stage mark 8, respectively, must be accurately matched. Furthermore, the distances L ₁ and L ₂ between the inner surface of the stage 6 and the outer surface of the outer frame 12 are extremely small, and it is required that the pellicle 10 be accurately mounted in a predetermined pellicle mounting portion 9. . However, since this pellicle mounting work is performed relying on the intuition of the operator, it is extremely difficult to accurately mount the pellicle 10 in a predetermined pellicle mounting portion 9.

If the pellicle 10 is not attached to the predetermined pellicle attachment part 9, even if the pellicle 10 is inserted into the opening 6a of the stage 6 and the photomask 1 with the pellicle 10 attached is placed on the stage 6, the cross It becomes impossible to accurately match the linear alignment mark 4 and the stage mark 7, and the linear alignment mark 5 and the stage mark 8, respectively, and the photomask 1 equipped with this pellicle 10 cannot be used for the transfer process. In addition, a cross-shaped alignment mark 4 and a stage mark 7,
The pellicle 10 is adjusted while adjusting the linear alignment mark 5 and the stage mark 8, respectively.
When placing the photomask 1 equipped with the pellicle on the stage 6 from above the stage 6, if the pellicle 10 is installed misaligned from the predetermined pellicle mounting part 9, the inner surface of the stage 6 and the outer surface of the outer frame 12 Since the distances L ₁ and L ₂ between them are extremely small, the pellicle 10 will collide with the stage 6, resulting in damage to the stage 6 and the pellicle 10.

As mentioned above, the pellicle 10 with very high accuracy
must be mounted on the photomask 1, and the accuracy of its mounting is determined by the standard of the reduction projection exposure apparatus used in the transfer process, but normally only a deviation of ±0.2 mm is allowed. Since only the photomask 1 to which the pellicle 10 is attached while maintaining this attachment accuracy can be used for the transfer process, it is required to confirm the attachment accuracy when the pellicle 10 is attached to the photomask 1. .

The present invention has been developed in view of the above circumstances, and has been developed to provide a photomask structure that allows the pellicle to be accurately attached to a predetermined pellicle attachment part, and that also allows the accuracy of the attachment to be confirmed. The purpose is to provide.

[Means for solving problems]

The present invention was made to achieve the above-mentioned object, and a photomask having a pattern formed on the main surface of a light-transmitting substrate roughly indicates the pellicle position near the area of the pellicle mounting portion surrounding the pattern. The photomask structure is characterized in that a pellicle position measuring means is formed inside and/or outside of the pellicle position coarse indicating section.

[Example 1] FIG. 1 is a plan view showing a photomask structure according to Example 1 of the present invention, and FIG. 2 is a perspective view showing a state in which a pellicle is attached to a photomask having the photomask structure according to Example 1 of the present invention. FIG. 3 is a plan view showing a pellicle position coarse indicating section and a pellicle position measuring means; FIG. 4 is a plan view showing a part of a state in which a pellicle is attached to a predetermined pellicle attachment section;
FIGS. 5 and 6 are plan views showing a part of the pellicle in a state in which the pellicle is installed with a deviation from a predetermined pellicle installation part.

As shown in FIG. 1, the photomask structure according to the first embodiment has a main surface of a photomask 15 in which an F-shaped light-shielding film pattern 14 such as a Cr film is formed on the main surface of a light-transmitting substrate 13 such as glass. On the top, there are coarse pellicle position indicating sections 16, 17, 18, and 19, and pellicle position measuring means 16a, 17a, 18a, and 19a that correspond to the coarse pellicle position indicating sections 16 to 19 and are located inside thereof. It forms. Furthermore, a cross-shaped alignment mark 4 and a linear alignment mark 5 are also formed on the main surface of the photomask 15. On the other hand, as shown in FIG. 2, the pellicle 20 consists of a translucent film 21 whose main surface is square, and an outer frame 22 that supports the translucent film 21.

As shown in FIG. 3, each of the pellicle position rough indication parts 16 to 19 is comprised of a hook-shaped light-shielding film pattern formed by connecting a, b, c, d, e, and f with a straight line. In addition, the pellicle position measuring means 1
6a to 19a are on a straight line from each point b of the pellicle position rough indication parts 16 to 19 to the center point (not shown) on the main surface of the transparent substrate 13, respectively.
It is formed by connecting three square light-shielding film patterns facing toward the center point.

In the case of Example 1, x and y in FIG. 3, and the length of one side of the square light-shielding film pattern constituting the pellicle position measuring means 16a to 19a, are each set to 1 mm. Further, as shown in FIG. 4, when the four vertices of the lower side of the outer frame 22 of the pellicle 20 on the photomask 15 side are located at each point g of the pellicle position measuring means 16a to 19a,
The pellicle 20 is attached to a predetermined pellicle attachment portion 23 (see FIG. 1) of the photomask 15. Note that the predetermined pellicle mounting portion 23 is an inner portion of a square formed by connecting each g point (a square formed by a dashed line in FIG. 1), and surrounds the light-shielding film pattern 14. There is.

Next, we will explain how to attach the pellicle 20 to the photomask 15 in which the pellicle position coarse indicating parts 16 to 19 and the pellicle position measuring means 16a to 19a are formed, and how much the pellicle 20 is displaced from the predetermined pellicle mounting part 23. Explain how to measure.

When attaching the pellicle 20 to a predetermined pellicle attaching section 23, the pellicle position rough indicating sections 16 to 19
Using this as a guide, attach the mask so that the four vertices of the lower side of the photomask 15 side of the outer frame 22 are located at each point g. As shown in Figure 4, the pellicle 20
When the pellicle 20 is attached, the pellicle 20 is attached to a predetermined pellicle attachment portion 23. Further, if the pellicle 20 is not attached to the predetermined pellicle attachment part 23, as shown in FIGS. 5 and 6,
An operator visually observes the positional relationship between the square light-shielding film pattern constituting the pellicle position measuring means 16a to 19a and the lower side of the outer frame 22, and determines the deviation amounts M ₁ and M ₂ in each case, Check M ₃ and M ₄ .

If the photomask 15 having the photomask structure according to the first embodiment is used, the pellicle mounting portion 2 can be moved to the predetermined pellicle mounting portion 2 using the pellicle position rough indication portions 16 to 19 as a guide.
3, the pellicle 20 can be attached to it. Further, when the pellicle 20 is mounted with a deviation from the predetermined pellicle mounting portion 23, the amount of deviation can be confirmed using the pellicle position measuring means 16a to 19a. Furthermore, if the amount of deviation is not within a predetermined mounting accuracy (for example, ±0.2 mm), it can be immediately determined that the photomask equipped with this pellicle cannot be used for the transfer process.

The shape of the pellicle position rough indication parts 16 to 19 can be selected from any shape that serves as a guideline when attaching the pellicle, and the number is not limited to four, but at least one is sufficient. The formation location may also be any location outside the area of the pellicle mounting portion. In addition, the pellicle position measuring means 16
The shapes and dimensions of a to 19a can be selected as appropriate. For example, as shown in FIG. 24. Furthermore, as shown in FIG. 2B, it may be a grid-like pellicle position measuring means 25 formed inside the coarse pellicle position indicating parts 16 to 19. moreover,
The number of square light-shielding film patterns constituting the pellicle position measuring means 16a to 19a is not limited to three and can be selected as appropriate, and each square light-shielding film pattern is connected at its apex. You don't have to.

In the first embodiment, the predetermined position of the pellicle attachment part 23 is set to point g as shown in FIG. 4, and when the positional relationship as shown in _FIG . ₂ or M ₃ and M ₄ , but conversely, the predetermined position of the pellicle attachment part 23 is set to the positional relationship as shown in Fig. 5 or 6, and the positional relationship shown in Fig. 4 is also used as the amount of deviation. good. The setting of the predetermined position of the pellicle mounting portion is the same in the following second and third embodiments.

[Example 2] FIG. 7 is a plan view showing a photomask structure according to Example 2 of the present invention, and FIG. 8 is a perspective view showing a state in which a pellicle is attached to a photomask having a photomask structure according to Example 2 of the present invention. FIG. 9 is a plan view showing the pellicle position rough indicator and the pellicle position measuring means, FIG. 10 is a plan view showing a part of the pellicle installed in a predetermined pellicle installation section, and FIG. 11 is a plan view showing the pellicle position measuring means. FIG. 3 is a plan view showing a part of the pellicle in a state where the pellicle is attached with a deviation from a predetermined pellicle attachment portion.

As shown in FIG. 7, the photomask structure according to the second embodiment has an F-shaped white pattern formed by removing a light-transmitting film such as a Cr film on the main surface of a light-transmitting substrate 13 such as glass. Photomask 2 with 26 formed
On the main surface of 7, a pellicle position rough indication part 28, 2
9, 30, and this pellicle position coarse/coarse indicator 28~
Pellicle position measuring means 28a, 29a, 30a corresponding to 30 and located inside the pellicle position measuring means 28a, 29a, 30a
It is formed by forming. Further, a portion 31 near the edge on the main surface of the light-transmitting substrate 13 is also blanked out by removing the light-shielding film, and a cross-shaped alignment mark 4 made of a light-transmitting film is provided in the near-edge portion 31. and a linear alignment mark 5 are formed. On the other hand, as shown in FIG. 8, the pellicle 32 consists of a transparent film 33 whose main surface is circular, and a ring-shaped outer frame 34 that supports the transparent film 33.

As shown in FIG. 9, the pellicle position rough indication parts 28 to 30 each have a band-like shape surrounded by circular arcs hk, ij having curvatures corresponding to the outer surface of the outer frame 34 and straight lines hi, kj. It consists of a white pattern.
In addition, pellicle position measuring means 28a to 30a
are on a straight line from the center point n on the circular arc hk of the pellicle position coarse indicating parts 28 to 30 to the center point (not shown) on the main surface of the transparent substrate 13, respectively.
Transparent substrate 13 with three square white patterns
It is formed by connecting a line toward the center point on the main surface of the plane.

In the case of Example 2, the distance between the arc hk and the arc ij is 1
mm, and the pellicle position measuring means 28a to 30
The length of each side of the square outline pattern constituting a is 0.6 mm. Further, as shown in FIG. 10, when the outer circumferential circle of the outer frame 34 of the pellicle 32 on the photomask 27 side is located at each point l and m (see FIG. 9) of the pellicle position measuring means 28a to 30a. , the pellicle 32 is attached to a predetermined pellicle attachment portion 35 (see FIG. 7) of the photomask 27. Note that the predetermined pellicle mounting portion 35 is connected to each pellicle position measuring means 28a to 30.
This is the inner part of the circle (the circle formed by the one-dot chain line in FIG. 7) that passes through each point l and m of point a, and surrounds the white pattern 26.

In the second embodiment, the predetermined pellicle mounting portion 35
The method for attaching the hepellicle 32 is the same as in the first embodiment. Further, when the pellicle 32 is not attached to the predetermined pellicle attachment portion 35, as shown in FIG.
The operator visually observes the positional relationship between the square white pattern of ~30a and the outer circumferential circle of the outer frame 34, and determines the amount of deviation.
Check _M5 . According to the photomask having the photomask structure according to the second embodiment, the same effects as in the first embodiment can be obtained.

The shape of the pellicle position rough indication parts 28 to 30 can be selected from any shape that will serve as a guide when attaching the pellicle, and the number thereof is not limited to three, but at least one is sufficient. Further, the shapes and dimensions of the pellicle position measuring means 28a to 30a can be selected as appropriate; for example, as shown in FIG. 12c,
The pellicle position measuring means 36 may be formed by connecting three elliptical outline patterns. Furthermore, as shown in FIG. 12d, three arc-shaped white patterns having the same curvature as the curvature of the outer surface of the outer frame 34 are placed on the inside of the pellicle position coarse indicating parts 28 to 30 at predetermined intervals. The pellicle position measuring means 37 may be arranged in parallel.

[Example 3] As shown in FIG. 13, the photomask structure according to Example 3 is a photomask in which an F-shaped light-shielding film pattern 14 such as a Cr film is formed on the main surface of a transparent substrate 13 such as glass. 15, a pellicle position coarse indicator 38 and an outer pellicle position measuring means 3 outside the pellicle position coarse indicator 38 are provided on the main surface of the pellicle position coarse indicator 38.
9 and 40, and an inner pellicle position measuring means 41 inside the pellicle position coarse indicating section 38.

The pellicle position rough indicator 38 is made of a light-shielding film pattern, and the interval between the square outer periphery 38a and the square inner periphery 38b is 1 mm.
8a is the pellicle attachment part 23 shown in Example 1.
(see Figure 1), and this outer periphery 38a
The inner part becomes the pellicle mounting part 42. The outer pellicle position measuring means 39 extends from the outer periphery 38a to 1
The outer pellicle position measuring means 40 consists of a light-shielding film pattern formed on the outer side of the outer pellicle position 39 with a line width of 0.1 mm.
It consists of a light-shielding film pattern formed 1 mm outward from the line, and its line width is 0.1 mm. The inner pellicle position measuring means 41 consists of a light-shielding film pattern formed 1 mm inside from the outer periphery 38b, and its line width is
It is 0.1mm.

When attaching the pellicle 20 shown in Example 1 to a predetermined pellicle attaching portion 42, use the pellicle position coarse indicating portion 38 as a guide and attach it so that the lower side of the outer frame 22 on the photomask 15 side overlaps the outer periphery 38a. . At this time, the photo mask 15 of the outer frame 22
If the lower edge of the side completely overlaps the outer periphery 38a, the pellicle 20 is attached to the predetermined pellicle attachment portion 42. The pellicle 20 is attached to a predetermined pellicle attachment part 4
If the pellicle is installed with a deviation from the position shown in FIG. In other words,
For example, when one side of the lower side of the outer frame 22 on the photomask 15 side is located between the outer pellicle position measuring means 39 and the outer periphery 38a, the operator visually confirms where that side is located. By doing this, you can find out the amount of deviation.

The outer periphery 38a and the inner periphery 38b of the pellicle position rough indicator 38 may have any shape other than a square shape depending on the pellicle to be attached. Also, the outer circumference 3
Dimensions such as the distance between 8a and the inner periphery 38b and the line widths of the outer and inner pellicle position measuring means 39, 40, 41 are also selected as appropriate. Furthermore, the outer pellicle position measuring means and the inner pellicle position measuring means are not limited to two pieces and one piece, respectively, but may be provided in an appropriate number as needed.

[Effect of idea]

According to the photomask structure of the present invention, the pellicle can be accurately attached to a predetermined pellicle attachment part using the pellicle position rough indication part as a guide, and furthermore, the pellicle position measurement means can be used to accurately attach the pellicle to a predetermined pellicle attachment part. You can check the accuracy. and,
When the mounting accuracy of the pellicle is not within a predetermined mounting accuracy, it can be immediately determined that the photomask fitted with the pellicle cannot be used in the transfer process, and workability in the transfer process can be greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a photomask structure according to Embodiment 1 of the present invention, FIG. 2 is a perspective view showing a state in which a pellicle is attached to a photomask having a photomask structure according to Embodiment 1 of the present invention, and FIG. 3 is a pellicle. FIG. 4 is a plan view showing a rough position indicating section and a pellicle position measuring means; FIG.
5 and 6 are plan views showing a part of the state in which the pellicle is installed with a deviation from the predetermined pellicle installation part, and FIG. 7 is a plan view showing a photomask structure according to Example 2 of the present invention. FIG. 8 is a perspective view showing a state in which a pellicle is attached to a photomask having a photomask structure according to a second embodiment of the present invention, FIG. 9 is a plan view showing a pellicle position rough indicator and a pellicle position measuring means, and FIG. 10 11 is a plan view showing a portion of the pellicle attached to a predetermined pellicle attachment portion; FIG. 11 is a plan view showing a portion of the pellicle attached with a deviation from the predetermined pellicle attachment portion; 13 is a plan view showing a photomask structure according to Embodiment 3 of the present invention, FIG. 14 is a plan view showing a conventional photomask structure, and FIG. 15 is a plan view showing a photomask structure according to a third embodiment of the present invention. A perspective view showing the installation stage, FIG. 16 shows the cross-shaped alignment mark and stage mark,
FIG. 17 is a perspective view showing a state in which a pellicle is attached to a conventional photomask; FIG.
The figure is a sectional view of a photomask equipped with a pellicle and a stage. 13... Light-transmitting substrate, 14... Light-shielding film pattern,
15, 27... Photomask, 16, 17, 18,
19, 28, 29, 30, 38... Pellicle position coarse indicator, 16a, 17a, 18a, 19a, 2
4, 25, 28a, 29a, 30a, 36, 3
7, 39, 40, 41... Pellicle position measuring means, 20, 32... Pellicle, 23, 35, 42...
Pellicle attachment part, 26...white pattern.

Claims (1)

[Scope of utility model registration request] A photomask in which a pattern is formed on the main surface of a translucent substrate has a pellicle position rough indication part near the area of the pellicle mounting part surrounding the pattern, and a pellicle position inside and/or outside of the pellicle position rough indication part. A photomask structure comprising a measuring means.