KR20020092024A - Sequence alignment system and the method - Google Patents

Abstract

The present invention grasps the positional relationship between the specific pattern of the substrate and the alignment mark before the substrate is transferred to the exposure area, and the position of the alignment mark of the mask and the predetermined pattern of the substrate before the substrate is transferred to the exposure area and the exposure operation proceeds. Provided are a sequential alignment device and method for grasping a relationship to move a mask stage or to move and move a substrate stage.

It includes a substrate alignment system for determining the positional relationship between a predetermined alignment mark of the substrate and a predetermined pattern for alignment before the substrate is transferred to the exposure area; A mask-to-substrate alignment system for determining a positional relationship between a predetermined pattern of the substrate and an alignment mark of a mask projected onto the predetermined pattern of the substrate when the substrate is positioned in an exposure area; The position error value between the predetermined pattern of the substrate and the alignment mark is calculated based on the value input from the substrate alignment system, and is projected onto the predetermined pattern of the substrate and the predetermined pattern of the substrate based on the value input from the mask to substrate alignment system. It can be achieved by having a host PC that calculates position error values between alignment marks of the masks to be moved and corrects the position by moving the mask or the substrate based on these position error values.

Description

Sequential Alignment System and Method {SEQUENCE ALIGNMENT SYSTEM AND THE METHOD}

The present invention relates to a mask in which an original pattern is engraved in an exposure apparatus and an alignment device for transferring the pattern to a specific position of a substrate to be exposed, in particular, alignment with a specific pattern of the substrate before the substrate is transferred to an exposure area. Determine the positional relationship between the marks, and move the mask stage or move the substrate stage to find the positional relationship between the alignment mark of the mask and a predetermined pattern of the substrate before the substrate is transferred to the exposure area and the exposure operation proceeds. An alignment device and method are provided.

In the exposure equipment, the alignment device is an essential device for transferring the shape of the pattern to specific positions of various types of substrates on which a predetermined pattern engraved on a mask is to be exposed.

Therefore, various types of alignment apparatuses are used for this purpose. Most alignment of alignment apparatuses is performed when the substrate is at the position to be exposed or alignment is not performed at the exposure position, and the alignment operation is completely completed. After that, the exposure operation proceeds sequentially.

In film carrier type exposure equipment, a technique of aligning the substrate by punching the perforations using a mechanically fixed pin when the substrate is transferred to the exposure area is widely used. .

An example of an alignment device using mechanically fixed pins is US Pat. No. 5,021,821.

This is because, as shown in FIG. 1, the light irradiated from the irradiation light source 1 is irradiated to the reticle 3 positioned on the reticle support member 4 through the mirror 2, and then the projection lens 5 is turned on. In an exposure apparatus which is capable of forming a predetermined pattern formed on the reticle 3 on the film 6 through, the film 6 on the pin 9 fixed on the film pressing member 8 before exposure. Alignment is performed so that the perforations 7 may be fitted.

However, mechanical alignment using these pins is difficult to transport the film precisely in a straight line when the film is transferred to the exposure position. It can be increased by friction, which can reduce the alignment accuracy, so that the thickness of the film is thinned to 30㎛ or less recently, and the alignment degree of 10㎛ or less can be satisfied to satisfy the trend requiring high precision by miniaturization of the pattern. There is a hard problem.

Many other types of exposure devices use TTL (Through The Lens) alignment as a way to improve the alignment accuracy. That is, the predetermined alignment mark on the mask is aligned with the predetermined alignment mark existing at the specific position of the substrate through the imaging lens system. In the conventional method, when performing the alignment operation using the TTL alignment method, various alignment devices are used depending on where the alignment mark exists in the substrate.

One such alignment device is U.S. Patent 5,198,857.

3 and 4, the photomask side alignment mark (hereinafter referred to as MM) of the mask M and the film side alignment mark of the film F are shown. mark: hereinafter referred to as FM), in which the light irradiated from the irradiation system 10 is projected through the mask M positioned in the photomask holder M11 in the system as shown in FIG. 4) is irradiated to the film F and aligned as shown in FIG. 4 when the image MM 'of the MM is exactly aligned with the position of FM, and aligned if the image MM' of the MM is not exactly aligned with the location of FM. It is determined that it is not, the system controller 40 drives the servo motor M12 to move the photomask holder M11 to align.

In this case, the detection system 30 is used to determine whether the alignment is performed, and the detection system 30 includes an objective lens 31, a condenser lens 32, and a high sensitivity photoelectric converter. Detector 33, which is a transducer, is used, and the output of the detector 33 is input to the system controller 40 through the amplifier 34, based on the output value of the detector 33 in the system controller 40. It is to determine the alignment.

However, the alignment device using the TTL alignment method using the conventional photoelectric conversion sensor is difficult to adjust the sensor, it may be sensitive to the noise in the equipment to reduce the alignment accuracy.

In addition, by inserting a hole for a separate alignment in the film to reduce the use area of the film, when using the equipment should be added to the user additional alignment holes in the film.

In addition, when the alignment mark of the substrate is in the effective exposure area, that is, the area in which the exposure pattern is present, the light source for the alignment system used at this time should be a non-exposure light source because the alignment operation is usually performed before exposure. If the light source to be used is an exposure light source, the photosensitive agent applied on the substrate is exposed to light, which adversely affects the exposure of the pattern. Therefore, when manufacturing the imaging system, it is necessary to configure an imaging lens system in which chromatic aberration is corrected in consideration of this non-exposure light source, which makes designing / manufacturing of the imaging system difficult.

In addition, in the case of a device in which a pattern is previously inscribed into a film before exposure such as BGA by performing only TTL alignment in the exposure area, an error amount due to miss alignment at the time of incorporating a pattern into the film cannot be compensated during exposure. .

The present invention has been made in view of the above, and the positional relationship between the predetermined pattern of the substrate and the alignment mark at the stage before the substrate is positioned in the exposure area, and after the substrate enters the exposure area, the predetermined pattern of the substrate and the predetermined alignment of the mask It is an object of the present invention to provide a sequential sorting apparatus and method that can improve the sorting accuracy by grasping the positional relationship between marks and sorting based on these values.

Another object of the present invention is to provide a sequential alignment device that can eliminate errors caused by chromatic aberration of an optical system by using an exposure light source as an alignment light source during alignment.

1 is a view showing an alignment device in a conventional exposure apparatus.

2 is a view showing the alignment device of another conventional embodiment.

3 and 4 are views for explaining the operation of another conventional embodiment

5 is a block diagram of a sequential sorting apparatus according to the present invention.

6 is an example of a pattern recognized by the substrate alignment system of the present invention.

7 is a diagram showing the configuration of another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: substrate alignment system 200: mask to substrate alignment system

300: host PC 400: mask stage drive unit

101: substrate 102: substrate stage

103: camera holder 201: exposure light source

202: mask stage 203: mask

204: light mask 205: projection optical system

A sequential alignment apparatus according to the present invention for achieving the above object, can transfer the original pattern of the mask to a desired position of the substrate between the mask in which the original pattern is engraved and the substrate on which the original pattern is to be transferred. An alignment apparatus, comprising: a substrate alignment system for determining a positional relationship between a predetermined alignment mark of a substrate and a predetermined pattern for alignment before the substrate is transferred to the exposure area; A mask-to-substrate alignment system for determining a positional relationship between a predetermined pattern of the substrate and an alignment mark of a mask projected onto the predetermined pattern of the substrate when the substrate is positioned in an exposure area; The position error value between the predetermined pattern of the substrate and the alignment mark is calculated based on the value input from the substrate alignment system, and is projected onto the predetermined pattern of the substrate and the predetermined pattern of the substrate based on the value input from the mask to substrate alignment system. It is characterized in that it comprises a host PC for calculating the position error value between the alignment marks of the mask to be moved to correct the position by moving the mask or the substrate based on these position error values.

The substrate alignment system photographs the predetermined pattern and the predetermined alignment mark of the substrate so that the positional relationship between the predetermined alignment mark and the predetermined pattern of the substrate located on the exposure surface side or the opposite side of the substrate may be captured by the electrical signal. It consists of at least two CCD cameras that deliver to a host PC.

In the mask-to-substrate alignment system, a light mask is disposed above the mask to block light sources other than the alignment mark portion of the mask so that the exposure light source is not irradiated to the effective exposure area of the substrate.

The sequential alignment method according to the present invention for achieving the above object, the original pattern of the mask can be transferred between the mask and the original pattern is transferred to the desired position of the mask between the base pattern to be formed the original pattern A first step of calculating a position error value between a predetermined pattern of the substrate and the alignment mark by grasping the positional relationship between the predetermined alignment mark of the substrate and the predetermined pattern for alignment before the substrate is transferred to the exposure area. Wow; A second position for calculating a position error value between the predetermined pattern of the substrate and the alignment mark of the mask by grasping the positional relationship between the predetermined pattern of the substrate and the alignment mark of the mask projected on the predetermined pattern when the substrate is positioned in the exposure area; Steps; And a third step of correcting the position by moving the mask or the substrate based on the position error values calculated in the first and second steps.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

First, the present invention is applicable to an exposure apparatus of a method in which a substrate is supplied in sheet form or roll form.

5 is a configuration diagram of a sequential alignment apparatus according to the present invention, which is a configuration diagram when a predetermined alignment mark exists on the exposure surface side of the substrate.

As shown therein, the substrate alignment for grasping the positional relationship between the perforation A and the alignment mark B of the substrate 101 before the substrate 101 disposed on the substrate stage 102 enters the exposure area. After the system 100 and the substrate 101 enter the exposure area, the mask is projected to the position of the perforation A by the perforation A and the exposure light source 201 on the substrate 101 ( The perforation A of the substrate 101 and the mask atmospheric material alignment system 200 for grasping the positional relationship between the alignment marks C of 203 and the value input from the substrate alignment system 100. The position error value between the alignment marks B is calculated, and the perforation A of the substrate 101 and the alignment mark C of the mask 203 based on the values input from the mask-to-substrate alignment system 200. A mask stay for driving the mask stage 202 based on these position error values by calculating position error values A host PC 300 which drives a substrate stage driver (not shown) for driving the driver 400 or the substrate stage 102 to precisely align the pattern on the effective exposure area in the mask 203 and the substrate 101. It is composed of

The substrate stage 101 has a base that is at least twice as large as the exposure area exposed at least once in the direction in which the substrate 101 is supplied, and the substrate alignment system 100 is positioned above the front half of the base. It is composed.

Substrate alignment system 100 is composed of a plurality of CCD camera (CCD11-CCD14) for photographing the perforation (A) and the alignment mark (B) on the substrate 101 and delivers it to the host PC 300 as an electrical signal The CCD cameras CCD11-CCD14 are supported by the camera holder 103.

The mask-to-substrate alignment system 200 of the mask 203 projected to the perforation A and the position of the perforation A on the substrate 101 after the substrate 101 enters the exposure area. For identifying the positional relationship of the alignment mark C, the alignment mark of the mask 203 positioned under the exposure area of the substrate stage 102 and projected by the perforation A and the exposure light source 201. (C) has a plurality of CCD cameras (CCD21, CCD22) for photographing and delivering them to the host PC 300 as an electrical signal, these CCD cameras (CCD21, CCD22) are also supported by a camera holder (not shown) do.

In addition, a light mask 204 is disposed on the mask 203 to implement the mask-to-substrate alignment system 200, and the light mask 204 is an alignment mark (C) portion of the mask 203. By blocking other light sources, the exposure light source 201 is not irradiated to the effective exposure area of the substrate 101 so that the exposure light source 201 can be used as the alignment light source.

According to the present invention configured as described above, first, the positional relationship between the perforation A and the alignment mark B of the substrate 101 is detected before the substrate 101 enters the exposure area.

That is, the alignment mark B existing in the effective exposure area (that is, the area where the exposure pattern exists) of the substrate 101 and the outside of the effective exposure area (that is, the exposure before the substrate 101 is located in the exposure area). While inside the area, the positional relationship of the perforations A present in the area outside the exposure pattern is used to align.

For example, when the pattern as shown in FIG. 6 is recognized by the CCD cameras CCD11-CCD14, the host PC 300 tilts the horizontal, vertical, or inclination of each side between the perforation A and the alignment mark B. FIG. The position error value is calculated from the positional relationship, and the like is used for alignment, and the position error value calculation operation is completed until the exposure operation for the substrate located in the exposure area is completed and then transferred for the next operation.

On the other hand, after the positional relationship between the perforation A and the alignment mark B of the base 101 is determined as described above, when the base 101 enters the exposure area, the perforation A of the base 101 The positional relationship between the alignment marks C of the overmask 203 is grasped.

That is, the alignment pattern C of the mask 203 is projected to the perforation A position of the substrate 101 through the projection optical system 205 by the light irradiated by the exposure light source 201, in which case the light mask By 204, the light irradiated by the exposure light source 201 is not irradiated to portions other than the alignment pattern C of the mask 203.

The perforation A of the substrate 101 and the alignment mark C of the mask 203 projected onto the perforation A are recognized by the CCD cameras CCD21 and CCD22 and transferred to the host PC 300. The host PC 300 calculates the positional relationship between the perforation A and the alignment pattern C, that is, the position error value, based on this.

In addition, the host PC 300 determines that the position error value and the substrate price 101 between the perforation A and the alignment mark B of the substrate 101 calculated just before the substrate 101 enters the exposure area. The mask 203 is driven by driving the mask stage driver 400 based on the position error value between the perforation A of the substrate 101 and the alignment mark C of the mask 203 calculated after entering the exposure area. By moving along the X, Y and θ axes, the pattern on the effective exposure area in the mask 203 and the substrate 101 is finally precisely aligned.

That is, the host PC 300 aligns the perforation (A) and the alignment mark (B) based on the position error value between the perforation (A) and the alignment mark (B), the perforation (A) and the mask Perforation (A) and alignment mark (C) are aligned based on the positional error value between alignment marks (C) of (203). After aligning perforation (A) and alignment mark (B) in this way, As the perforation A and the alignment mark C are aligned, the alignment mark B of the substrate 101 and the alignment mark C of the mask 203 are automatically aligned.

Here, the substrate stage 102 may be driven and aligned through a substrate stage driving unit (not shown) in addition to moving and aligning the mask 203 by driving the mask stage driving unit 400.

When the alignment is completed as described above, the light mask 204 is removed to perform exposure.

7 is a diagram illustrating a system configuration of another embodiment of the present invention, in which the alignment mark of the substrate is not on the exposure surface side but on the opposite side, and the substrate alignment system 100A is the substrate 101. Only the point of performing alignment using the rear alignment mark of the base material 101 positioned below the different from the above embodiment, the principle is the same as the above embodiment, the detailed description thereof is weak.

The present invention is not limited to the above described embodiments, and various modifications and changes can be made by those skilled in the art, which are included in the spirit and scope of the present invention as defined in the appended claims.

As described above, the present invention obtains the following effects.

First, by performing the alignment by calculating the position error value for alignment over the second step immediately before the substrate enters the exposure area and after the entry, it is possible to implement the same or higher alignment accuracy than in the prior art.

Second, alignment can be easily performed when the mask pattern needs to be aligned with the exposed surface or the opposite surface of the substrate. That is, the alignment of the primary substrate alignment system in the upward or downward direction of the substrate can be easily performed as well as the alignment can be performed simultaneously in the vertical direction or completely removed to align through the mask to substrate alignment system. Various sorting methods can be implemented according to the arrangement of the substrate alignment system, such as only being able to be performed. In other words, as the user of the equipment can take the substrate alignment system as an option, there is an advantage of broadening the application field of the exposure equipment.

Third, by using the exposure light source as the alignment light source, it is possible to eliminate the alignment error due to chromatic aberration when using the non-exposure light source, thereby increasing the overall alignment accuracy.

Claims (7)

In the alignment device to transfer the original pattern of the mask to the desired position of the substrate between the mask on which the original pattern is inscribed and the original pattern is transferred to form the original pattern, A substrate alignment system for determining a positional relationship between a predetermined alignment mark of the substrate and a predetermined pattern for alignment before the substrate is transferred to the exposure area; A mask-to-substrate alignment system for determining a positional relationship between a predetermined pattern of the substrate and an alignment mark of a mask projected onto the predetermined pattern of the substrate when the substrate is positioned in an exposure area; The position error value between the predetermined pattern of the substrate and the alignment mark is calculated based on the value input from the substrate alignment system, and is projected onto the predetermined pattern of the substrate and the predetermined pattern of the substrate based on the value input from the mask to substrate alignment system. And a host PC for calculating position error values between alignment marks of the masks to be moved and correcting the position by moving the mask or the substrate based on these position error values. The method of claim 1, wherein the predetermined pattern of the substrate is Sequential alignment device, characterized in that located outside the effective exposure area. The method of claim 1, wherein the substrate alignment system And a positional relationship between a predetermined alignment mark and a predetermined pattern of the substrate positioned on the exposure surface side or the opposite side of the substrate. The system of claim 3, wherein the substrate alignment system And at least two CCD cameras photographing the predetermined pattern and the predetermined alignment mark of the substrate and transmitting the predetermined pattern and the predetermined alignment mark to the host PC as an electrical signal. The system of claim 1, wherein the mask to substrate alignment system And at least one CCD camera for photographing a predetermined pattern of the substrate and an alignment mark of a mask projected on the predetermined pattern of the substrate and transmitting the alignment mark to the host PC as an electrical signal. The system of claim 1, wherein the mask to substrate alignment system And a light mask arranged above the mask to block light sources other than the alignment mark portions of the mask so that the exposure light source is not irradiated to the effective exposure area of the substrate. In the alignment method to transfer the original pattern of the mask to a desired position of the substrate between the mask in which the original pattern is inscribed and the original pattern is transferred to form the original pattern, A first step of identifying a positional relationship between a predetermined alignment mark of the substrate and a predetermined pattern for alignment before the substrate is transferred to the exposure area, and calculating a position error value between the predetermined pattern of the substrate and the alignment mark; A second position for calculating a position error value between the predetermined pattern of the substrate and the alignment mark of the mask by grasping the positional relationship between the predetermined pattern of the substrate and the alignment mark of the mask projected on the predetermined pattern when the substrate is positioned in the exposure area; Steps; And a third step of correcting the position by moving the mask or the substrate based on the position error values calculated in the first and second steps.