JP2000228353A - Method and device of transfer exposure, and reticule used therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of transfer exposure, having smooth connection between stripes and having less irregularity in line width precision. SOLUTION: Two stripes 25 and 26 on a reticle which are transferred side by side on a sensitive substrate 11 are formed on non-adjacent places on the reticle. Accordingly, a space can be secured between the two stripes 25 and 26, and a double exposure region and a margin part, where the pattern of a boundary part is selectively arranged, can be provided. The boundary of the stripes can be provided on an arbitrary place on the margin part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for transferring and exposing a liquid crystal device or a large semiconductor device having a device size larger than the field of view of a projection optical system of an exposure apparatus, and an apparatus therefor. Further, the present invention relates to a reticle used in the method. In particular, the present invention relates to a transfer exposure method and the like improved so that pattern images can be satisfactorily joined on a sensitive substrate. Energy rays referred to in this specification include light, electron beams, ion beams, and X-rays.

[0002]

2. Description of the Related Art When the size of an entire device pattern to be transferred onto a sensitive substrate is larger than the field of view of a projection optical system, a method of dividing the pattern into a plurality of pieces and transferring and exposing the divided patterns on the sensitive substrate is used. Can be used. Then, in order to reduce the displacement of the pattern in the joining portion, a double exposure region is provided in the joining portion, and this region is inclinedly illuminated to reduce the displacement of the joining portion by a so-called gray splicing method.

[0003]

However, the above-described oblique illumination method has a problem that a method of transferring the reticle and the sensitive substrate while continuously moving the reticle cannot be adopted. Also,
In the above-described oblique illumination method, there is a problem that the variation in the line width accuracy of the pattern becomes large instead of the joint becoming inconspicuous.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and enables transfer while continuously moving a reticle and a sensitive substrate, making the connection between stripes inconspicuous and having less variation in line width accuracy. And a transfer exposure apparatus and a reticle used therefor.

[0005]

According to a first aspect of the present invention, there is provided a transfer exposure method, comprising: dividing a pattern to be transferred onto a sensitive substrate (whole pattern) into a plurality of stripes; While scanning the reticle and the sensitive substrate respectively, each stripe is illuminated with an energy ray, and the energy ray passing through the stripe is projected and imaged on the sensitive substrate, and each stripe (image) is formed on the sensitive substrate. A transfer exposure method for transferring the whole pattern by joining together; forming stripes to be transferred so as to be adjacent on the sensitive substrate at distant places which are not adjacent on the reticle, and performing a plurality of scans. It is characterized in that each stripe is subjected to transfer exposure.

In a transfer exposure method according to a second aspect of the present invention, a pattern (whole pattern) to be transferred onto a sensitive substrate is divided into a plurality of partial regions and formed on a reticle, and each partial region is illuminated with an energy beam. A transfer exposure method for projecting and forming an energy ray passing through the partial area on a sensitive substrate, and connecting the partial areas (images) to transfer the entire pattern on the sensitive substrate; In the reticle, a partial area that is transferred so as to be adjacent to each other is formed at a distant place that is not adjacent to the reticle, and a margin portion that is double-exposed to the same place on the sensitive substrate is provided between the partial areas of the reticle. And selectively forming a boundary portion of a pattern over two adjacent partial regions (images) on the sensitive substrate in a margin portion of any of the partial regions on the reticle,
The margin portion is also exposed at the same exposure intensity as the other portions.

[0007] By forming two partial regions (stripe) on the reticle which are transferred so as to be adjacent on the sensitive substrate at separated positions which are not adjacent to each other on the reticle, a space between the two partial regions (stripe) is formed. Space. Here is a double exposure area for gray splicing,
A margin portion for selectively arranging the pattern of the boundary portion can be provided. In the margin portion, the boundary of the stripe can be set at an arbitrary position. Therefore, various measures can be taken to improve the pattern connection. In the present specification, a stripe means a partial area to be exposed while continuously moving (scanning) the reticle and the sensitive substrate.

According to a first aspect of the present invention, there is provided a transfer exposure apparatus comprising: a movable stage for mounting a sensitive substrate; a movable stage for mounting a reticle having a pattern to be transferred onto the sensitive substrate; A plurality of illumination optical systems for illuminating the pattern with energy rays for each partial area, and a plurality of projection optical systems for projecting and forming an energy ray passing through the partial area at an appropriate position on the sensitive substrate,
The pattern to be transferred onto the sensitive substrate (whole pattern) is divided into a plurality of stripes and formed on the reticle, and the adjacent stripes on the sensitive substrate are formed at distant locations that are not adjacent on the reticle. It is characterized in that each stripe is transferred and exposed while scanning.

A transfer exposure apparatus according to a second aspect of the present invention comprises: a movable stage on which a sensitive substrate is mounted; a movable stage on which a reticle having a pattern to be transferred onto the sensitive substrate is mounted; A transfer comprising: a plurality of illumination optical systems for illuminating a pattern with energy rays for each partial area; and a plurality of projection optical systems for projecting and forming an energy ray passing through the partial area at an appropriate position on a sensitive substrate. An exposure apparatus, wherein partial areas to be transferred adjacent to each other on a sensitive substrate are formed at distant places that are not adjacent to each other on a reticle, and between the partial areas of the reticle, at the same location on the sensitive substrate. A double-exposed margin is provided, and the boundary of the pattern extending over two adjacent partial areas (images) on the sensitive substrate is selected as the margin of any one of the partial areas on the reticle. Formed in, the margin portion is also characterized by exposing the same exposure intensity the other portions.

A reticle according to a first aspect of the present invention is a reticle in which a pattern (entire pattern) to be transferred onto a sensitive substrate is formed by dividing the pattern into a plurality of stripes; The reticle is formed at a distant place that is not adjacent to the reticle.

A reticle according to a second aspect of the present invention is a reticle in which a pattern to be transferred onto a sensitive substrate (whole pattern) is formed by being divided into a plurality of partial regions;
The partial areas that are transferred next to each other on the sensitive substrate
The reticle is formed at a distant place that is not adjacent to the reticle, and between the partial areas of the reticle, there is provided a margin portion that is double-exposed at the same place on the sensitive substrate,
A boundary portion of a pattern extending over two adjacent partial regions (images) on the sensitive substrate is selectively formed in a margin portion of any of the partial regions on the reticle.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically showing a configuration of a transfer exposure apparatus according to one embodiment of the present invention. The transfer exposure apparatus 1 has five exposure optical systems arranged in the left and right directions (Y direction) in the figure. That is, as the illumination optical system 3, five light sources 21a
-E and five condenser lens arrays 23a-e. Further, as the projection optical system 9, five sets of projection lens arrays 2
9 The pitch between the five optical systems is twice the pitch of the stripes 25 and 26 of the reticle 5. Since one stripe 25 and 26 can be exposed while continuously scanning in the X direction for each system, five rows of stripes can be exposed by one scan.

The light source 21 is a laser light source for visible light or ultraviolet light in this example. The condenser lens array 23 forms an image of the illumination light 24 emitted from the light source 21 on the reticle 5.

The reticle 5 is shown as having two upper and lower stripes 25 and 26 for convenience of illustration, but in reality, as shown in FIG.
Direction) in the XY plane at the same position.
On the reticle 5, 10 rows of stripes 25a-e, 2
6a to 6e are formed. Odd-numbered stripes 25a to 25e and even-numbered stripes 26a counted from the left of the drawing.
Are arranged so as to be displaced in the X direction by the length of the stripe or more. However, the positional relationship between the odd-numbered and even-numbered stripes, for example, the pitch in the Y direction and the relative positional relationship in the X direction are still normal. If there is room in the size of the reticle, divide the stripe into three or more
It can be arranged in more than steps. The present invention includes such techniques within its scope.

The reticle 5 is mounted on a reticle stage 7. The reticle stage 7 is movable in the XY directions in the figure. When exposing each of the stripes 25 and 26,
The reticle stage 7 continuously moves (scans) in the X direction.

The projection lens array 29 forms an image of the light passing through the reticle 5 on the substrate 11. The pattern of the stripes 25 and 26 of the reticle 5 is transferred onto the substrate 11 at the same magnification. The substrate 11 is mounted on a substrate stage 13. The substrate stage 13 is movable in XY directions in the figure. When exposing each of the stripes 25 and 26, the substrate stage 13 continuously moves (scans) in the X direction. The reticle stage 7 and the substrate stage 13 are provided with an interference type coordinate display device (not shown).

The transfer exposure apparatus 1 transfers and exposes odd-numbered stripes 25a to 25e simultaneously. During the exposure, the reticle stage 7 and the substrate stage 13 are synchronously scanned in the opposite direction of the X direction, and the pattern in the stripe 25 is transferred onto the substrate 11. After exposing the odd-numbered stripes 25a to 25e, the reticle 5 and the substrate 11 are advanced in the Y direction by the stripe pitch. Then, the even-numbered stripes 26a to 26e are adjusted on the optical axes of the illumination optical system and the projection optical system, and the even-numbered stripes 26a to 26e are similarly transferred onto the substrate while performing synchronous scanning in the X direction.

On the substrate 11, the odd-numbered stripes (images) and the even-numbered stripes are joined, and the entire pattern on the reticle 5 is transferred onto the substrate 11.

FIG. 2 is a view for explaining an embodiment in which a joint is made inconspicuous by oblique illumination using a double exposure area. (A) is a plan view showing a stripe arrangement in the entire reticle, (B) is an enlarged plan view of each stripe, and (C) is a graph showing a dose distribution of each stripe.

Double exposure regions 31, 35, 37 and 41 are provided at the ends of the stripes 25 and 26 in the Y direction.
Then, two stripes 25 adjacent on the sensitive substrate,
The same pattern is formed on both the odd-numbered stripes 25 and the even-numbered stripes 26 in the double exposure regions 35 and 37 transferred to the boundary portion 26. Then, these double exposure areas 35 and 37 are double exposed to the same location on the sensitive substrate.

At the end of each stripe of each exposure optical system, a filter is provided so that the irradiation intensity decreases linearly. The installation position of the filter can be, for example, a position immediately before the reticle or immediately after the reticle. The light that has passed through the filter gives an inclined dose as indicated by reference numerals 51, 55, 57, and 61 in FIG. The sum of the two tilt doses is equal to the doses 53 and 59 of the single exposure area. As a result, each pattern in the double exposure area is also exposed with the same intensity.

FIG. 3 is a diagram for explaining an embodiment in the case where an island pattern also exists at the boundary between stripes.
The four rectangles 71, 72, 73 and 74 are patterns to be transferred (white patterns giving dose). These patterns partially overlap the boundary 77 of the original partial region (stripe). If the division is performed as it is, a joining portion occurs in the pattern. Therefore, a margin portion having a width b is provided at the end of the left and right partial regions, and each pattern is accommodated in one of the left and right partial regions as much as possible. That is, as shown in FIG. 3B, 72 ′ on the reticle,
The pattern is divided into a 74 'pattern and 71' and 73 'patterns and is divided into left and right partial areas.

In this case, the single exposure area and the margin portion (double exposure area) are exposed with the same intensity. But,
In the margin portion, since the pattern exists only in one of the partial areas, each pattern has the same exposure amount. Naturally, in this case, no pattern connection occurs, and there is almost no deviation or line width defect of each pattern.

FIG. 4 is a diagram for explaining an embodiment in the case where a pattern with a bent edge exists at the boundary of a stripe. FIG. 4A shows the entire pattern, and a dashed line 87 in the figure is a substantial boundary between stripes (partial regions). Patterns 81a and 82a on the left side of the chain line
4B are formed in the left stripe as shown in FIG. 4B, and the right patterns 81b and 82b from the dotted line are
As shown in (C), the stripe is formed on the right side stripe. In this case, the connection occurs at the steps indicated by reference numerals 84 and 85, and both are points where the inner angles of the patterns are greater than 270 ° and 180 °. Therefore, even if there is some poor connection, it is hardly noticeable. The margin portion indicated by 90 in the drawing is a double exposure region, but since the pattern exists only in one of the stripes, the exposure is performed at the same intensity as the other regions.

FIG. 5 is a diagram for explaining an embodiment in which a pattern dividing point is divided into two points. As shown in FIG. 5A, a line pattern 91 extends across the boundary of the stripe.
92 and 93 exist. In this case, the pattern of the right stripe is represented by 91a, 92a,
A stepped pattern represented by 93a is shown, and the pattern of the left stripe is represented by 91b and 92b as shown in FIG.
b and 93b. In the pattern after the transfer, as shown in FIG. 5A, the intersections between the stripe boundaries and the pattern edges are indicated by 101 to 106. The interval between the intersections 101 to 106 is smaller than the width b of the margin portion. In this example, since the joining occurs at different positions of one pattern, the extent to which the joining failure affects the line width accuracy is reduced to half.

As described above, by moving the boundary of the stripe (partial region) and the boundary of the pattern to an arbitrary position in the margin portion (double exposure region), the connection failure does not adversely affect the performance of the device. Can be.

[0027]

As is apparent from the above description, according to the present invention, transfer can be performed while continuously moving the reticle and the substrate to be exposed, the connection between stripes is not conspicuous, and the variation in line width accuracy is small. A method, a transfer exposure apparatus, and a reticle used therefor can be provided.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a configuration of a transfer exposure apparatus according to one embodiment of the present invention.

FIG. 2 is a view for explaining an embodiment in which a joint is made inconspicuous by oblique illumination using a double exposure area.
(A) is a plan view showing a stripe arrangement in the entire reticle, (B) is an enlarged plan view of each stripe, and (C) is a graph showing a dose distribution of each stripe.

FIG. 3 is a diagram for explaining an embodiment in a case where an island pattern also exists at a boundary between stripes.

FIG. 4 is a diagram for explaining an embodiment in the case where a pattern with a bent edge exists at a boundary of a stripe;

FIG. 5 is a diagram for explaining an embodiment in which a pattern dividing point is divided into two points.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Exposure apparatus 3 Illumination optical system 5 Reticle 7 Reticle stage 9 Projection optical system 11 Substrate 13 Substrate stage 21 Light source 23 Condenser lens row 24 Imaging line 25 Odd-numbered stripe 26 Even-numbered stripe 27 Imaging line 29 Projection lens 31, 35, 37, 41 Double exposure area 33, 39 Single exposure area 51, 55, 57, 61 Double exposure area dose 53, 59 Single exposure area dose

Claims (14)

[Claims] 1. A pattern (whole pattern) to be transferred onto a sensitive substrate is divided into a plurality of stripes and formed on a reticle. Each of the stripes is illuminated with an energy beam while scanning the reticle and the sensitive substrate. A transfer exposure method for projecting and forming an energy beam passing through the stripe on a sensitive substrate, and connecting the stripes (images) on the sensitive substrate to transfer the entire pattern; A transfer exposure method, wherein stripes to be transferred to a reticle are formed at distant places that are not adjacent to each other on a reticle, and each stripe is transferred and exposed while performing a plurality of scans. 2. An odd-numbered stripe of all the stripes is formed at a first position on a reticle while maintaining a relative positional relationship between the stripes, and an even-numbered stripe of all the stripes is formed. Forming the stripes at the second position on the reticle while maintaining the positional relationship between the stripes, and exposing each of the even-numbered stripe groups or the odd-numbered stripe groups at one time. The transfer exposure method according to claim 1, wherein: 3. The transfer exposure method according to claim 1, wherein a double-exposed area is provided between the stripes. 4. An identical pattern (double exposure pattern) is formed at each end of two stripes on a reticle which are transferred adjacently on a sensitive substrate, and when exposing each stripe, 4. The method according to claim 1, wherein the same pattern is double-exposed to the same place on the sensitive substrate, and a normal dose is given by two exposures.
The transfer exposure method according to the above. 5. A pattern (whole pattern) to be transferred onto a sensitive substrate is divided into a plurality of partial areas, formed on a reticle, and each partial area is illuminated with an energy ray. A projection exposure image on a sensitive substrate, and connecting the respective partial areas (images) on the sensitive substrate to transfer the whole pattern; A margin portion that is double exposed is provided at a location, and a boundary portion of a pattern extending over two adjacent partial regions (images) on the sensitive substrate is selectively formed in a margin portion of any of the partial regions on the reticle. And transferring the margin portion with the same exposure intensity as the other portions. 6. The transfer exposure method according to claim 5, wherein each pattern is contained in one partial region on the reticle as much as possible so that the pattern does not cross the boundary of the partial region on the reticle as much as possible. 7. The transfer exposure method according to claim 5, wherein the boundary of the partial area on the reticle is matched with a step portion (including a bent portion) of the pattern. 8. When a linear pattern exists across two partial regions, the pattern dividing point is divided into a plurality of locations separated by a dimension smaller than the width of the margin in the longitudinal direction. Item 6. The transfer exposure method according to Item 5. 9. A movable stage on which a sensitive substrate is mounted, a movable stage on which a reticle having a pattern to be transferred onto the sensitive substrate is mounted, and a pattern on the reticle is converted by an energy beam for each partial area. A plurality of illumination optical systems for illuminating, and a plurality of projection optical systems for projecting and forming an energy ray passing through the partial region at an appropriate position on the sensitive substrate, wherein a pattern to be transferred onto the sensitive substrate (whole) Pattern) is divided into a plurality of stripes and formed on a reticle, adjacent stripes on the sensitive substrate are formed on non-adjacent and separated positions on the reticle, and each stripe is transferred and exposed while performing a plurality of scans. A transfer exposure apparatus characterized by the above-mentioned. 10. A movable stage on which a sensitive substrate is mounted, a movable stage on which a reticle having a pattern to be transferred onto the sensitive substrate is mounted, and a pattern on the reticle is converted by an energy beam for each partial area. What is claimed is: 1. A transfer exposure apparatus comprising: a plurality of illumination optical systems for illuminating; and a plurality of projection optical systems for projecting and forming an energy ray passing through the partial region at an appropriate position on a sensitive substrate; Partial areas to be transferred so as to be adjacent to each other are formed on reticle at distant places that are not adjacent to each other, and a margin portion is provided between the partial areas of the reticle to be double-exposed at the same place on the sensitive substrate. A boundary portion of a pattern extending over two adjacent partial regions (images) on the sensitive substrate is selectively formed in a margin portion of one of the partial regions on the reticle, and the margin portion is also formed in another portion. A transfer exposure apparatus, which performs exposure at the same exposure intensity as a minute. 11. A reticle in which a pattern (whole pattern) to be transferred onto a sensitive substrate is formed by being divided into a plurality of stripes; stripes adjacent on the sensitive substrate are separated from each other on the reticle. A reticle characterized in that the reticle is formed in a place where it is located. 12. An odd-numbered stripe of all the stripes is formed at a first position on a reticle in a state where the positional relationship between the stripes is normally maintained, and an even-numbered stripe of all the stripes is formed. The reticle according to claim 11, wherein the third stripe is formed at a second position on the reticle while maintaining a positional relationship between the stripes. 13. At each end of a stripe on two reticles that are transferred side by side on a sensitive substrate,
13. The reticle according to claim 11, wherein the same pattern (end pattern) is formed. 14. A reticle in which a pattern (whole pattern) to be transferred onto a sensitive substrate is formed by being divided into a plurality of partial regions; It is formed at a distant place that is not adjacent on the reticle, and a margin portion that is double exposed at the same place on the sensitive substrate is provided between partial areas of the reticle, and it is adjacent on the sensitive substrate A reticle wherein a boundary portion of a pattern extending over two partial regions (images) is selectively formed in a margin portion of any one of the partial regions on the reticle.