JP7520785B2 - Exposure apparatus, exposure method, and article manufacturing method - Google Patents

Description

The present invention relates to an exposure apparatus, an exposure method, and a method for manufacturing an article.

In the manufacture of flat panel displays (FPDs) such as liquid crystal displays and organic electroluminescence displays, and semiconductor devices, exposure apparatuses are used to transfer the pattern of an original such as a mask onto a substrate such as a glass plate or wafer coated with a photosensitive agent. Such exposure apparatuses are required to align the pattern of the original with high precision to the pattern area on the substrate. In general, alignment marks for alignment are formed on the lower layer, and the alignment marks formed on the lower layer are measured when exposing the upper layer, allowing the pattern to be transferred to the upper layer in a highly accurate overlap with the pattern formed on the lower layer.

In addition, in the exposure process using an exposure device, it is also necessary to reduce production costs by optimizing the panel layout and making full use of the substrate. The size of the original can be a constraint in optimizing the panel layout. For example, when pattern 51 of original 3a as shown in FIG. 9(a) is transferred to substrate 6a as shown in FIG. 9(b), the panel layout will be as shown in FIG. 9(b). In FIG. 9(b), wasted space is generated in area 52 where panels cannot be produced.

Patent Document 1 discloses a method for optimizing the panel layout in the above case by combining an exposure that transfers the entire area of the original (called the first exposure) with an exposure that transfers a partial area of the original (called the second exposure). By combining the first exposure and the second exposure, it is possible to produce panels with a panel layout such as that shown in Figure 9(c).

JP 2010-85793 A

The second exposure in Patent Document 1 is divided into a process of transferring the pattern of the original by shading a portion of the original from light, and a process of transferring alignment marks to determine the misalignment between the pattern formed in the first exposure and the pattern formed in the second exposure. In the method described in Patent Document 1, the pattern formation and the alignment mark formation are transferred at different times during the second exposure, which may reduce productivity.

Therefore, the present invention aims to provide an exposure apparatus that can reduce the decline in productivity.

In order to achieve the above object, an exposure apparatus as one aspect of the present invention is an exposure apparatus that exposes a pattern of a second layer onto a substrate on which a first layer is formed, the first layer including a first pattern area including a first pattern formed by light transmitted through a pattern formation area of an original, and a second pattern area including a second pattern formed by light transmitted through a partial area of the pattern formation area of the original and smaller than the first pattern area, the first pattern area including a first alignment mark for aligning a pattern of the first pattern area in the first layer with a pattern of the first pattern area in the second layer, a second alignment mark for aligning a pattern of the second pattern area in the first layer with a pattern of the second pattern area in the second layer, and a third alignment mark for determining a positional deviation between the first pattern area and the second pattern area in the first layer. and a fourth alignment mark for aligning a pattern of the second pattern area in the first layer with a pattern of the second pattern area in the second layer, and a fifth alignment mark for determining a misalignment between the first pattern area and the second pattern area in the first layer are formed in the second pattern area.The exposure apparatus has a detection unit that detects the alignment marks, and a control unit that controls the alignment of the original and the substrate, and the control unit controls the alignment of the original and the substrate for pattern formation in the second layer based on the result of detecting the first alignment mark by the detection unit , the result of simultaneously detecting the second alignment mark and the fourth alignment mark by the detection unit, and the result of detecting the third alignment mark and the fifth alignment mark by the detection unit .

The present invention provides an exposure apparatus that can reduce declines in productivity.

FIG. 1 is a schematic diagram showing a configuration of an exposure apparatus. 11A and 11B are diagrams for explaining an exposure method in Comparative Example 1. 13A and 13B are diagrams for explaining an exposure method in Comparative Example 2. 13A and 13B are diagrams for explaining an exposure method in Comparative Example 3. 5A and 5B are diagrams illustrating a relationship between an original and a light-shielding portion in the first embodiment. 10 is a flowchart showing the procedure of an exposure process for an upper layer and a lower layer. FIG. 2 is a diagram showing the state of an exposed substrate. 13A and 13B are diagrams illustrating a relationship between an original and a light-shielding portion in a second embodiment. FIG. 2 is a diagram for explaining a panel layout.

Below, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Note that in each drawing, the same reference numbers are used for the same components, and duplicated explanations will be omitted.

First Embodiment
(Configuration of Exposure Apparatus)
The configuration of an exposure apparatus in this embodiment will be described. The exposure apparatus in this embodiment is an apparatus used in a lithography process when manufacturing devices such as semiconductor devices and flat panel displays (FPDs). The exposure apparatus transfers a pattern of an original (mask) onto a substrate coated with resist, thereby forming a latent image pattern in a pattern area of the substrate. The exposure apparatus in this embodiment is a so-called step-and-scan scanning exposure apparatus that transfers the pattern of the original onto multiple pattern areas on the substrate via a projection optical system.

Figure 1 is a schematic diagram showing the configuration of an exposure apparatus 100 in this embodiment. In this embodiment, a coordinate system is defined in which the surface on which the substrate 6a is placed is the XY plane, and the direction perpendicular to the XY plane is the Z direction. The exposure apparatus 100 can include an illumination optical system 1, an alignment measurement unit 2a, off-axis measurement units 2b and 2c, an original stage 3b, a light shielding unit 4, a projection optical system 5, a substrate stage 6b, a base plate 7, and a control unit 8.

Light emitted from a light source (not shown) illuminates the original 3a via an optical system in the illumination optical system 1. The illumination optical system 1 has a member that defines the area in which the original 3a is illuminated, and for example, a strip-shaped or arc-shaped light is illuminated onto the original 3a.

The original 3a and substrate 6a (e.g., a glass substrate) are held by the original stage 3b and substrate stage 6b, respectively, and are positioned at positions that are nearly optically conjugate via the projection optical system 5 (the object plane and image plane of the projection optical system 5).

The projection optical system 5 is, for example, a mirror projection type projection optical system composed of multiple mirrors, has a predetermined projection magnification (for example, 1x, 1/2x, 2x, etc.), and projects the pattern formed on the original 3a onto the substrate 6a.

The original stage 3b and the substrate stage 6b scan in a direction (Y direction in this embodiment) perpendicular to the optical axis direction (Z direction) of the projection optical system 5, in synchronization with each other, at a speed ratio according to the projection magnification of the projection optical system 5.

The light shielding unit 4 can be driven in the scanning direction (Y direction in this embodiment) or in a direction perpendicular thereto (X direction in this embodiment) to adjust the exposure area of the original 3a. This allows the pattern formed on the original 3a to be transferred to the pattern area on the substrate 6a with an optimal panel layout.

The exposure apparatus 100 can complete the exposure process for one substrate 6a by sequentially repeating the process for each of the multiple pattern areas on the substrate 6a while stepping the substrate stage 6b. When transferring the pattern of the original 3a to each pattern area on the substrate 6a in this manner, the pattern area may be aligned with the original 3a.

The exposure apparatus 100 has an alignment measurement unit 2a (first detection unit) between the illumination optical system 1 and the original 3a, and the alignment measurement unit 2a includes at least one alignment scope. In this embodiment, the alignment measurement unit 2a has two alignment scopes spaced a predetermined distance apart in the X direction. In addition, the exposure apparatus 100 is configured so that each alignment scope can be driven in the XY plane. Therefore, the alignment measurement unit 2a can observe each of the alignment marks (alignment marks) formed in the pattern area on the substrate 6a and each of the alignment marks formed on the original 3a via the projection optical system 5.

Also, off-axis measurement units 2b and 2c (second detection units) are provided between the projection optical system 5 and the substrate 6a, and the off-axis measurement units 2b and 2c include at least one off-axis scope. Each of the off-axis measurement units 2b and 2c in this embodiment has two off-axis scopes spaced a predetermined distance apart in the X direction. Furthermore, the exposure apparatus 100 is configured so that each off-axis scope can be driven in the XY plane. Therefore, the off-axis measurement units 2b and 2c can observe each of the alignment marks formed in the pattern area on the substrate 6a.

The exposure apparatus 100 can measure multiple marks simultaneously by aligning the positions of the alignment measurement unit 2a and the off-axis measurement units 2b and 2c with the alignment marks formed on the substrate 6a.

The control unit 8 controls the illumination optical system 1, the alignment measurement unit 2a, the off-axis measurement units 2b and 2c, the original stage 3b, the light shielding unit 4, and the substrate stage 6b. The control unit 8 can also obtain the positional deviation and shape of the pattern area based on the positions of the alignment marks on the pattern area measured by the alignment measurement unit 2a and the off-axis measurement units 2b and 2c. The control unit 8 can perform scanning exposure of the substrate 6a while controlling the moving speed and position adjustment of the original stage 3b and the substrate stage 6b, the projection magnification of the projection optical system 5, and the like, based on the relative positions of the alignment marks on the original 3a and the alignment marks on the pattern area.

In the exposure process of flat panel displays (FPDs) and the processes before and after the exposure process, first, a photosensitive material is applied to the substrate 6a, and the pattern of the original 3a is transferred (exposed) to the first layer (hereinafter referred to as the lower layer) of the photosensitive material, and a developed pattern is formed by a subsequent development process. Then, a photosensitive material is again applied to the substrate 6a, and the pattern of the original 3a is transferred (exposed) to the second layer (hereinafter referred to as the upper layer) of the photosensitive material, and a developed pattern is formed by a subsequent development process. By repeating this process, a substrate with a laminated structure having multiple layers can be obtained. In the exposure process of FPDs and the like, it is extremely important to align the pattern of the lower layer with the pattern of the upper layer.

To align the lower layer with the upper layer, generally, alignment marks are formed along with the pattern of the original when the lower layer is exposed, and when the upper layer is exposed, the alignment marks are detected to align the patterns of the lower layer with those of the upper layer. Also, in order to detect the positional deviation and shape of the pattern area with high accuracy using a small number of alignment marks, it is preferable to place the alignment marks at the edges of the pattern area (in this embodiment, a total of six points: four points near the corners of the rectangular pattern area and two points near the midpoints of the long sides).

In this embodiment, in order to optimize the panel layout on the substrate 6a, scanning exposure is performed by combining an exposure that transfers the entire area of the original 3a (hereinafter referred to as a first exposure) with an exposure that transfers a partial area of the original (hereinafter referred to as a second exposure). Note that the second exposure in this embodiment is a so-called half-shot exposure that transfers half the area of the original 3a. Before explaining the procedure for scanning exposure in this embodiment, the procedure for scanning exposure in comparative examples 1 to 3 will be explained.

Note that multiple alignment marks can be formed in a pattern area, but the number formed can be determined according to the number of scopes in the alignment measurement unit 2a and off-axis measurement units 2b and 2c, and the required accuracy. In the following explanations of Comparative Examples 1 to 3 and this embodiment, it is assumed that alignment marks formed in six locations are measured simultaneously by six scopes in the alignment measurement unit 2a or off-axis measurement units 2b and 2c to correct the shape of one pattern area.

(Comparative Example 1)
In Comparative Example 1, a method of changing the intervals between the alignment scopes of the alignment measurement unit 2a and the off-axis scopes of the off-axis measurement units 2b and 2c (driving the scopes) between the first exposure and the second exposure will be described. FIG. 2 is a diagram for explaining scanning exposure in Comparative Example 1.

Figure 2(a) is a diagram showing original plate 3a in Comparative Example 1. Nine alignment marks 21 are formed for the purpose of measuring six alignment marks 21 in the second exposure in the upper layer described later. In the first exposure, the entire area shown in Figure 2(a) is transferred to substrate 6a. At this time, nine alignment marks are formed in first pattern area 22, as shown in Figure 2(c).

Figure 2(b) is a diagram showing the state of original plate 3a in the second exposure. A light-shielding portion 24 blocks a portion of original plate 3a (for example, an area that blocks half of the pattern formed on original plate 3a). In the second exposure, the area of original plate 3a that is not blocked by light-shielding portion 24 is transferred to substrate 6a as shown in Figure 2(b). At this time, six alignment marks are formed in second pattern area 23 as shown in Figure 2(d).

2(c) and 2(d) are diagrams showing the results of scanning and exposing the entire area of the substrate 6a by combining the first exposure and the second exposure. In FIG. 2(c), the first pattern area 22 is highlighted with a thick line. When scanning and exposing the first pattern area 22 by the first exposure, the shape of the first pattern area 22 is corrected by measuring the alignment marks 21a to 21f formed in the lower layer. Each scope of the alignment measurement unit 2a measures the alignment marks 21b and 21e. Each scope of the off-axis measurement unit 2b measures the alignment marks 21a and 21d, and each scope of the off-axis measurement unit 2c measures the alignment marks 21c and 21f. In the first exposure, the intervals between the scopes of the alignment measurement unit 2a, the intervals between the scopes of the off-axis measurement unit 2b, and the intervals between the scopes of the off-axis measurement unit 2c are all measured with a distance d1 between them.

In FIG. 2(d), the second pattern region 23 is highlighted with a thick line. When scanning exposure in the second pattern region 23 is performed by the second exposure, the shape of the second pattern region 23 is corrected by measuring the alignment marks 21g to 21l formed in the lower layer. Each scope of the alignment measurement unit 2a measures the alignment marks 21h and 21k. Each scope of the off-axis measurement unit 2b measures the alignment marks 21g and 21j, and each scope of the off-axis measurement unit 2c measures the alignment marks 21i and 21l. In the second exposure, the intervals between the scopes of the alignment measurement unit 2a, the intervals between the scopes of the off-axis measurement unit 2b, and the intervals between the scopes of the off-axis measurement unit 2c are all measured with a distance d2 between them.

As explained above, because the scope spacing in the first exposure is different from the scope spacing in the second exposure, it is necessary to drive the scopes in the alignment measurement unit 2a and the off-axis measurement units 2b and 2c. Due to structural limitations of the exposure apparatus 100, it is difficult to achieve high-speed driving of the scopes without incurring high costs. In addition, errors in driving the scopes may affect the measurement performance. It is also possible to increase the number of scopes, but this is disadvantageous in terms of cost.

(Comparative Example 2)
In Comparative Example 2, a method is described in which the intervals between the alignment scopes of the alignment measurement unit 2a and the off-axis scopes of the off-axis measurement units 2b and 2c are not changed between the first exposure and the second exposure (the scopes are not driven). In Comparative Example 2, the productivity can be improved compared to Comparative Example 1 by measuring the alignment marks formed during the first exposure in the lower layer during the second exposure in the upper layer. Fig. 3 is a diagram for explaining the scanning exposure in Comparative Example 2.

Figure 3(a) is a diagram showing original plate 3a in Comparative Example 2. Nine alignment marks 31 are formed for the purpose of measuring six alignment marks 31 in the second exposure in the upper layer described later. In the first exposure, the entire area shown in Figure 3(a) is transferred to the substrate. In the first exposure, the entire area shown in Figure 3(a) is transferred to the substrate 6a. At this time, nine alignment marks are formed in the first pattern area 32, as shown in Figure 3(c).

Figure 3(b) is a diagram showing the state of original plate 3a in the second exposure. A light-shielding portion 34 blocks a portion of original plate 3a (for example, an area that blocks half of the pattern formed on original plate 3a). In the second exposure, the area of original plate 3a that is not blocked by light-shielding portion 34 is transferred to substrate 6a as shown in Figure 3(b). At this time, three alignment marks are formed in second pattern area 33 as shown in Figure 3(d).

Figures 3(c) and 3(d) are diagrams showing the results of scanning exposure of the entire area of the substrate 6a by combining the first exposure and the second exposure. In Figure 3(c), the first pattern area 32 is highlighted with a thick line. When scanning exposure in the first pattern area 32 is performed by the first exposure, the shape of the first pattern area 32 is corrected by measuring the alignment marks 31a to 31f formed in the lower layer. Each scope of the alignment measurement unit 2a measures the alignment marks 31b and 31e. Each scope of the off-axis measurement unit 2b measures the alignment marks 31a and 31d, and each scope of the off-axis measurement unit 2c measures the alignment marks 31c and 31f. In the first exposure, the intervals between the scopes of the alignment measurement unit 2a, the intervals between the scopes of the off-axis measurement unit 2b, and the intervals between the scopes of the off-axis measurement unit 2c are all measured with a distance d1 between them.

In FIG. 3(d), the second pattern region 33 is highlighted with a thick line. When scanning exposure in the second pattern region 33 is performed by the second exposure, the shape of the second pattern region 33 is corrected by measuring the alignment marks 31g to 31l formed in the lower layer. Each scope of the alignment measurement unit 2a measures the alignment marks 31h and 31k. Each scope of the off-axis measurement unit 2b measures the alignment marks 31g and 31j, and each scope of the off-axis measurement unit 2c measures the alignment marks 31i and 31l. In the second exposure, the intervals between the scopes of the alignment measurement unit 2a, the intervals between the scopes of the off-axis measurement unit 2b, and the intervals between the scopes of the off-axis measurement unit 2c are all measured with a distance d1 between them, as in the first exposure.

As explained above, in Comparative Example 2, in the second exposure in the upper layer, alignment marks 31g, 31h, and 31i formed in the first exposure in the lower layer are used. This makes it unnecessary to drive the scope by adjusting the position of alignment mark 31 so that the scope spacing is d1 in both the first and second exposures. This makes it possible to improve the productivity of the exposure process compared to Comparative Example 1.

However, in the second exposure, the use of the alignment marks 31g, 31h, and 31i formed in the first exposure in the lower layer may lead to a decrease in the overlay accuracy. FIG. 3(e) is a diagram showing a state in which the position of the second pattern area 33 in the second exposure is shifted with respect to the first pattern area 32 in the first exposure. The target area 35 shown by the dotted line in FIG. 3(e) is the target position of the second pattern area 33 in the second exposure. As shown in FIG. 3(e), if there is an error in the relative positional relationship between the first pattern area 32 and the second pattern area 33 during the exposure of the lower layer, the shape of the second pattern area 33 cannot be accurately corrected even if the alignment marks 31g to 31l are measured during the second exposure of the upper layer. That is, in the second pattern area 33, the upper and lower layers cannot be accurately overlaid. This is because the shape correction of the pattern area is performed based on the detection result of the alignment marks, assuming that there is no relative positional deviation between the first pattern area 32 and the second pattern area 33 in the lower layer. The relative positional deviation between the first pattern region 32 and the second pattern region 33 in the lower layer can occur, for example, due to a driving error of the original stage 3b or the substrate stage 6b.

Compared to Comparative Example 1, this is an improvement in terms of productivity. However, compared to Comparative Example 1, this may be disadvantageous in terms of the overlay accuracy of the second pattern region 33.

(Comparative Example 3)
In Comparative Example 3, the method described in Patent Document 1 will be described. In Comparative Example 3, as in Comparative Example 2, a method will be described in which the intervals between the alignment scopes of the alignment measurement unit 2a and the off-axis scopes of the off-axis measurement units 2b and 2c are not changed between the first exposure and the second exposure (the scopes are not driven). In Comparative Example 3, the timing of forming the alignment marks 31g, 31h, and 31i described in Comparative Example 2 is performed at a different timing from that in Comparative Example 2, thereby reducing the adverse effect of the error in the relative position between the first pattern area and the second pattern area in the lower layer. FIG. 4 is a diagram for explaining the scanning exposure in Comparative Example 3.

Figure 4(a) shows the state of the original 3a in the first exposure. Six alignment marks 41 are formed for the purpose of measuring the six alignment marks 41 in the second exposure in the upper layer described later. In the first exposure, as shown in Figure 4(a), a light-shielding portion 44 is placed in a rectangular area in the center of the original 3a where no pattern is formed, to block some of the light.

Figure 4(b) is a diagram showing the state of the substrate 6a after the first exposure in the lower layer in the state of the original 3a shown in Figure 4(a). The area exposed in the first exposure is the first pattern area 42. When performing scanning exposure in the first pattern area 42 in the upper layer by the first exposure, the shape of the first pattern area 42 is corrected by measuring the alignment marks 41a to 41f formed in the lower layer. Each scope of the alignment measurement unit 2a measures the alignment marks 41b and 41e. Each scope of the off-axis measurement unit 2b measures the alignment marks 41a and 41d, and each scope of the off-axis measurement unit 2c measures the alignment marks 41c and 41f. In the first exposure, the intervals between the scopes of the alignment measurement unit 2a, the intervals between the scopes of the off-axis measurement unit 2b, and the intervals between the scopes of the off-axis measurement unit 2c are all measured with a distance d1 between them.

Figure 4(c) shows the state of the original 3a during the second exposure. The light-shielding portion 44 is driven to block a portion of the original 3a (for example, a region that blocks half of the pattern formed on the original 3a).

Figure 4(d) is a diagram showing the state of substrate 6a after the second exposure of the lower layer has been performed with master 3a in the state shown in Figure 4(c). The area exposed in the second exposure is second pattern area 43. At this time, alignment marks 41j, 41k, and 41l are also formed. After forming the pattern in second pattern area 43, a process of forming alignment marks 41g, 41h, and 41i is performed.

Figure 4(e) shows the state of the master 3a for forming alignment marks 41g, 41h, and 41i after the pattern formation by the second exposure of the lower layer has been performed. The light shielding section 44 is driven to shield the areas of the master 3a other than the areas where the three alignment marks are located.

Figure 4(f) is a diagram showing the state of the substrate 6a after the process of forming the alignment marks 41g, 41h, and 41i has been performed on the original 3a shown in Figure 4(e). The alignment marks 41g, 41h, and 41i are formed in the region 46. When performing scanning exposure in the second pattern region 43 by the second exposure, the shape of the second pattern region 43 is corrected by measuring the alignment marks 41g to 41l formed in the lower layer. Each scope of the alignment measurement unit 2a measures the alignment marks 41h and 41k, respectively. In addition, each scope of the off-axis measurement unit 2b measures the alignment marks 41g and 41j, respectively, and each scope of the off-axis measurement unit 2c measures the alignment marks 41i and 41l, respectively. In addition, in the second exposure, the spacing between the scopes of the alignment measurement unit 2a, the spacing between the scopes of the off-axis measurement unit 2b, and the spacing between the scopes of the off-axis measurement unit 2c are all measured with a spacing of d1 between them, as in the first exposure.

As described above, in Comparative Example 3, the alignment marks 41g, 41h, and 41i are not formed in the first exposure, but are formed after the second exposure, thereby improving the overlay accuracy. FIG. 4(g) is a diagram showing a state in which the position of the second pattern area 43 in the second exposure is shifted relative to the first pattern area 42 in the first exposure. The target area 45 shown by the dotted line in FIG. 4(g) is the target position of the pattern area in the second exposure. In Comparative Example 3, the alignment marks 41g, 41h, and 41i are formed at the position of the substrate 6a where the second pattern area 43 is formed in the second exposure, without driving the substrate stage 6b, and are therefore not affected by errors in the relative positions of the first pattern area 42 and the second pattern area 43.

However, in Comparative Example 3, after exposing the pattern in the second exposure of the lower layer, a separate process is required just to form the alignment marks 41g, 41h, and 41i, which reduces productivity. In addition, although there is no need to drive the substrate stage 6b between the process of exposing the pattern in the second exposure of the lower layer and the process of forming the alignment marks 41g, 41h, and 41i, there is a risk that the state of the projection optical system of the exposure apparatus 100 will change due to heat generated by exposure, etc. This may cause an error in the formation position of the alignment marks 41g, 41h, and 41i with respect to the second pattern region 43, which may lead to a decrease in overlay accuracy.

(Exposure Processing in the Present Embodiment)
In this embodiment, by measuring the relative positional shift between the first pattern area exposed by the first exposure and the second pattern area exposed by the second exposure, the layer overlay accuracy can be improved compared to comparative example 2.

The arrangement of the alignment marks on the original 3a in this embodiment will be described with reference to FIG. 5. In FIG. 5, only the alignment marks are shown to explain the exposure process in this embodiment, but in reality, a pattern to be transferred to the substrate 6a is formed in the pattern formation area of the original 3a. The areas on the original 3a in FIG. 5 drawn in white are areas that transmit or pass the irradiated light, and the alignment marks formed on the original 3a are transferred to the substrate 6a.

Figure 5(a) is a diagram showing the state of the original 3a and the light-shielding portion 4 in the first exposure of this embodiment. As shown in Figure 5(a), alignment marks P1L, P1R, P2L, P2R, P3L, P3R, P1M, P2M, and P3M are formed in the pattern formation region of the original 3a. In addition, when the distance between alignment marks P1M and P1L is j1 and the distance between alignment marks P1M and P1R is j2, the relationship j1 = j2 is satisfied.

In this embodiment, alignment marks Q1S, Q3S, Q1F, and Q3F are also formed. As shown in FIG. 5, alignment mark Q1S is formed near alignment mark P1M, and similarly alignment marks Q3S, Q1F, and Q3F are formed near alignment marks P3M, P1R, and P3R, respectively.

The light shielding unit 4 is provided directly under the original 3a and can be driven in, for example, the X direction. The position of the light shielding unit 4 is controlled by the control unit 8, so that the area of the original 3a to be transferred to the substrate 6a can be arbitrarily determined. In this embodiment, a first exposure in which the light shielding unit 4 does not shield the pattern formed on the original 3a (illuminating the first illumination area) is performed in combination with a second exposure in which the light shielding unit 4 shields half of the pattern formed on the original 3a (illuminating the second illumination area). One or more light shielding units 4 are provided in at least one of the following locations: the illumination optical system 1, between the illumination optical system 1 and the original 3a, between the original 3a and the projection optical system 5, the projection optical system 5, and between the projection optical system 5 and the substrate 6a.

Figure 5(b) is a diagram showing the state of the original 3a and the light-shielding portion 4 in the second exposure of this embodiment. As shown in Figure 5(b), by driving the light-shielding portion 4 in the X direction from the state shown in Figure 5(a), it is brought into a state where it overlaps with half the area of the original 3a. As a result, in the second exposure, only the pattern in half the area of the original 3a is transferred to the substrate 6a.

Next, the exposure method for the lower layer and the alignment method for the upper layer in this embodiment will be described in order. FIG. 6 is a flow chart showing the procedure for the exposure process for the lower layer and the upper layer in this embodiment. This exposure process is carried out by the control unit 8 controlling each part of the exposure apparatus 100.

In step S101, a first exposure of the base is performed with the original 3a and light-shielding portion 4 in the state shown in FIG. 5(a) (first exposure process). FIG. 7(a) is a diagram showing the state of the substrate 6a after the first exposure is performed in the first pattern region 73 in step S101. In the first pattern region 73, a latent image of the first pattern and a plurality of alignment marks is formed. In FIG. 7(a), alignment marks 71a-71f (first alignment marks), 71g-71i (second alignment marks), 72a-72b (third alignment marks), and 72c-72d are formed on the substrate 6a.

In step S102, the second exposure of the base is performed in the state of the original 3a and the light shielding unit 4 shown in FIG. 5(b) (second exposure process). The control unit 8 drives the light shielding unit 4 in the X direction to shield a part of the original 3a. A latent image of the second pattern and a plurality of alignment marks is formed in the second pattern region 76. FIG. 7(b) is a diagram showing the state of the substrate 6a after the second exposure is performed in the second pattern region 76 in step S102. The second pattern region 76 is the region indicated by the thick line in FIG. 7(b) and is a region that partially overlaps with the first pattern region 73. The region where the first pattern region 73 and the second pattern region 76 overlap is hereinafter referred to as the overlap region 77. In FIG. 7(b), alignment marks 74a to 74c (fourth alignment marks), 75a to 75b, and 75c to 75d (fifth alignment marks) are formed on the substrate 6a.

In step S103, the substrate 6a is transported from the exposure device 100 to a device that develops the latent image on the substrate 6a, and is developed (first development step). The developed substrate 6a is then transported to the exposure device 100. The alignment marks on the developed substrate 6a are in a state that can be measured by the alignment measurement unit 2a and the off-axis measurement units 2b and 2c.

In step S104, the substrate stage 6b is driven, and the alignment measurement unit 2a and the off-axis measurement units 2b and 2c measure the alignment marks 71a to 71f (first alignment marks). The alignment marks 71a to 71f are measured simultaneously using multiple scopes in the alignment measurement unit 2a and the off-axis measurement units 2b and 2c. For example, control information for the original stage 3b, substrate stage 6b, and projection optical system 5 is calculated so that all measurement values indicating the degree of overlay with the lower layer (values closer to 0 indicate higher overlay accuracy) become 0.

In step S105, a first exposure is performed on the upper layer based on the control information calculated in step S104. This allows the first pattern of the upper layer to be exposed so as to overlap the first pattern of the lower layer in the first pattern region 73. The control unit 8 transfers the pattern while controlling the relative positions of the original 3a and the substrate 6a.

In step S106, the substrate stage 6b is driven, and the alignment marks 71g-71i and the alignment marks 74a-74c are measured by the alignment measurement unit 2a and the off-axis measurement units 2b and 2c. The alignment marks 71g-71i and the alignment marks 74a-74c are measured simultaneously by multiple scopes in the alignment measurement unit 2a and the off-axis measurement units 2b and 2c.

In step S107, the substrate stage 6b is driven, and the off-axis measurement units 2b and 2c measure the alignment marks 72a and 72b and the alignment marks 75c and 75d formed in the overlapping region 77 shown in FIG. 7(b). At this time, the alignment marks 72a and 75c are within the field of view of one of the first scopes of the off-axis measurement units 2b or 2c. The alignment marks 72b and 75d are within the field of view of one of the second scopes of the off-axis measurement units 2b or 2c.

In step S108, based on the third alignment mark and the fifth alignment mark measured in step S107, array information regarding the relative positions of the first pattern region 73 and the second pattern region 76 formed in the lower layer is calculated.

Figures 7(c) and 7(d) are diagrams showing an example of a third alignment mark and a fifth alignment mark formed in the overlap region 77. In Figure 7(c), alignment mark 72a is formed so that its center coincides with that of alignment mark 75c. Alignment mark 72a and alignment mark 75c are, for example, different in size so that they can be distinguished from each other. Similarly, alignment mark 72b is formed so that its center coincides with that of alignment mark 75d.

In the example shown in FIG. 7(c), the deviation between the center positions of the alignment marks 72a and 75c and the center positions of the alignment marks 72b and 75d are measured. If the center positions are deviated, it is found that the relative positions of the first pattern area 73 and the second pattern area 76 are deviated. Based on the deviation amount between the center positions of the alignment marks 72a and 75c and the deviation amount between the center positions of the alignment marks 72b and 75d, it is found that the relative positions of the pattern areas have shifted in the X direction or Y direction. In addition, by calculating the difference between the deviation amount between the center positions of the alignment marks 72a and 75c and the deviation amount between the center positions of the alignment marks 72b and 75d, it is found that the relative positions of the pattern areas have shifted in the rotation direction around the Z axis. Alternatively, the relative positional deviation between the pattern regions may be calculated by calculating the average value of the deviation between the center positions of the alignment marks 72a and 75c, and between the center positions of the alignment marks 72b and 75d.

FIG. 7(d) shows an alignment mark with a different shape and arrangement from that of FIG. 7(c). In the example shown in FIG. 7(d), alignment mark 72a and alignment mark 75c are formed in overlapping region 77 so that they are arranged next to each other. By measuring the distance between alignment mark 72a and alignment mark 75c, the relative position shift between pattern regions can be calculated. A reference distance that serves as a reference between alignment marks is set in advance, and the relative position between pattern regions is calculated according to the amount of deviation from the reference distance. In the example shown in FIG. 7(d), the relative position between pattern regions can be calculated, as in the example of FIG. 7(c).

Also, mark shapes other than those shown in the examples of Figures 7(c) and 7(d) may be used. Also, while it has been described that alignment mark 72a and alignment mark 75c are formed in the overlapping area, it is sufficient if two alignment marks can be detected with one scope, and it is not necessary to perform the first exposure and the second exposure so that an overlapping area is always formed.

In step S109, a second exposure is performed on the upper layer based on the measurement information obtained by measuring the second alignment mark and the fourth alignment mark in step S107 and the arrangement information calculated in step S108 (third exposure process). This allows the upper layer pattern to be exposed so as to overlap the lower layer pattern in the second pattern area 76. Specifically, the amount of relative positional deviation between the pattern areas calculated in step S108 is removed from the measurement information obtained by measuring the second alignment mark and the fourth alignment mark in step S107. This reduces the effect of the relative positional deviation between the pattern areas, making it possible to perform layer overlap in the second pattern area 76 with higher accuracy. The control unit 8 transfers the pattern while controlling the relative positions of the original 3a and the substrate 6a.

In this embodiment, the multiple steps (steps S104, S106, S107) for detecting the first alignment mark, the second alignment mark, the third alignment mark, the fourth alignment mark, and the fifth alignment mark are collectively referred to as the detection step. The first exposure in step S105 may be performed after the measurement in step S106 or step S107, or after the calculation of the relative position error in step S108. In addition, in the flowchart of FIG. 6, an example in which the lower layer and the upper layer are exposed only by the same exposure apparatus has been described, but this is not limited to this. The upper layer and the lower layer may be exposed by different apparatuses. For example, steps S101 and S102 may be performed by another exposure apparatus having the same function as the exposure apparatus 100, the first development step may be performed, and steps S104 to S109 may be performed by the exposure apparatus 100.

As described above, in this embodiment, the relative position error between pattern regions is calculated and used for alignment of the second exposure, making it possible to improve the layer overlay accuracy compared to Comparative Example 2. In addition, the number of exposure steps can be reduced compared to Comparative Example 3, thereby improving productivity.

Second Embodiment
In the first embodiment, an example was described in which half the area of the original 3a is shielded by the light shielding portion 4 in the second exposure. The area shielded by the light shielding portion 4 may be determined by the layout in which the pattern of the original 3a is formed, and the layout in which the pattern is formed on the substrate 6a without waste. In this embodiment, an example is described in which 1/3 of the area of the original 3a is shielded by the light shielding portion 4. Note that the configurations of to are the same as those in the first embodiment, and therefore description thereof will be omitted. Furthermore, matters not mentioned in this embodiment follow the first embodiment.

The arrangement of the alignment marks on the original 3a in this embodiment will be described with reference to FIG. 8. In FIG. 8, only the alignment marks are shown to explain the exposure process in this embodiment, but in reality, a pattern to be transferred to the substrate 6a is formed. The white areas of the original 3a shown in FIG. 8 are areas that transmit or pass the irradiated light, and the alignment marks formed on the original 3a are transferred to the substrate 6a.

Figure 8 (a) is a diagram showing the state of the original 3a and the light-shielding portion 4 in the first exposure of this embodiment. The difference from the first embodiment is the positions of the alignment marks Q1S and Q3S. The alignment mark Q1S is positioned between the alignment marks P1L and P1M, and the alignment mark Q3S is positioned between the alignment marks P3L and P3M. This change is made because the area of the original 3a that is shielded by the light-shielding portion 4 in the second exposure is different from that in the first embodiment.

Figure 8 (b) is a diagram showing the state of the original 3a and the light-shielding portion 4 in the second exposure of this embodiment. The light-shielding portion 4 blocks 1/3 of the area of the original 3a, and 2/3 of the area is in a position to be transferred to the substrate 6a. As a result, an alignment mark is formed in the exposure area that is exposed in an overlapping manner in the first and second exposures, in the same manner as shown in Figure 7.

As described above, in this embodiment, the relative position error between pattern regions is calculated and used for alignment of the second exposure, making it possible to improve the layer overlay accuracy compared to Comparative Example 2. In addition, the number of exposure steps can be reduced compared to Comparative Example 3, thereby improving productivity.

<Embodiments of a method for manufacturing an article>
The method for manufacturing an article according to an embodiment of the present invention is suitable for manufacturing, for example, a flat panel display (FPD). The method for manufacturing an article according to this embodiment includes a step of forming a latent image pattern on a photosensitive agent applied on a substrate by exposure using the above-mentioned exposure device to obtain an exposed substrate, and a step (second development step) of developing the exposed substrate on which the latent image pattern has been formed in this step to obtain a developed substrate. Furthermore, this manufacturing method includes other well-known steps (oxidation, film formation, deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The method for manufacturing an article according to this embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article compared to conventional methods.

The above describes preferred embodiments of the present invention, but it goes without saying that the present invention is not limited to these embodiments, and various modifications and variations are possible within the scope of the gist of the invention.

2a Alignment measurement unit (first detection unit)
2b, 2c Off-axis measurement unit (second detection unit)
3a Original plate 6a Substrate 8 Control unit 71a, 71b, 71c, 71d, 71e, 71f Alignment marks (first alignment marks)
71g, 71h, 71i Alignment marks (second alignment marks)
72a, 72b Alignment marks (third alignment marks)
73 First pattern area 74a, 74b, 74c Alignment marks (fourth alignment marks)
75c, 75d Alignment marks (fifth alignment marks)
76 Second pattern area 100 Exposure device

Claims (12)

An exposure apparatus for exposing a pattern of a second layer onto a substrate on which a first layer is formed, the second pattern region including a first pattern formed by light transmitted through a pattern formation region of an original and a second pattern region smaller than the first pattern region, the second pattern region including a second pattern formed by light transmitted through a partial region of the pattern formation region of the original , the exposure apparatus comprising:
in the first pattern region, a first alignment mark for aligning a pattern of the first pattern region in the first layer with a pattern of the first pattern region in the second layer, a second alignment mark for aligning a pattern of the second pattern region in the first layer with a pattern of the second pattern region in the second layer, and a third alignment mark for determining a positional deviation between the first pattern region and the second pattern region in the first layer,
a fourth alignment mark for aligning a pattern of the second pattern region in the first layer with a pattern of the second pattern region in the second layer, and a fifth alignment mark for determining a positional deviation between the first pattern region and the second pattern region in the first layer are formed in the second pattern region;
The exposure apparatus includes:
A detection unit that detects an alignment mark;
a control unit for controlling alignment between the original and the substrate,
The exposure apparatus is characterized in that the control unit controls the alignment of the original and the substrate for pattern formation in the second layer based on the result of detection of the first alignment mark by the detection unit, the result of simultaneous detection of the second alignment mark and the fourth alignment mark by the detection unit, and the result of detection of the third alignment mark and the fifth alignment mark by the detection unit. The exposure apparatus according to claim 1, characterized in that the control unit obtains arrangement information indicating a positional deviation between the first pattern area and the second pattern area in the first layer based on the detection results of the third alignment mark and the fifth alignment mark detected by the detection unit, and uses the arrangement information to align the pattern of the second pattern area in the first layer with the pattern of the second pattern area in the second layer. the third alignment mark and the fifth alignment mark each include a plurality of alignment marks;
the detection unit includes a plurality of scopes;
3. The exposure apparatus according to claim 1, wherein at least one of the plurality of scopes simultaneously detects at least one of the third alignment marks and at least one of the fifth alignment marks. a projection optical system for projecting a pattern of the original onto the substrate;
4. The exposure apparatus according to claim 1, wherein the detection unit detects the alignment mark formed on the substrate without passing through the projection optical system. The detection unit includes a first detection unit and a second detection unit,
the first detection unit detects the first alignment mark, the second alignment mark, and the fourth alignment mark via the projection optical system;
5. The exposure apparatus according to claim 4, wherein the second detection unit detects the first alignment mark, the second alignment mark, the third alignment mark, the fourth alignment mark, and the fifth alignment mark without passing through the projection optical system. the first alignment mark, the second alignment mark, and the fourth alignment mark each include a plurality of alignment marks;
The exposure apparatus of claim 5, characterized in that the second detection unit detects, without passing through the projection optical system, an alignment mark among the first alignment marks that is not detected by the first detection unit, an alignment mark among the second alignment marks that is not detected by the first detection unit, and an alignment mark among the fourth alignment marks that is not detected by the first detection unit. the second pattern region includes an overlap region that overlaps a portion of the first pattern region,
7. The exposure apparatus according to claim 1, wherein at least one of the third alignment marks and at least one of the fifth alignment marks are formed in the overlapping region. a light shielding portion that blocks a part of the illumination light that is irradiated onto the original,
8. The exposure apparatus according to claim 1, wherein the second pattern area is an area that is illuminated by the light blocking portion blocking a part of the illumination light. The exposure apparatus according to any one of claims 1 to 8, characterized in that the second pattern area is half the area of the first pattern area. The exposure apparatus according to any one of claims 1 to 9, characterized in that the control unit aligns the original and the substrate for forming a pattern in the second layer by removing a relative positional deviation between the first pattern region and the second pattern region, so that the second pattern in the second layer overlaps the second pattern in the first layer. 1. An exposure method for exposing a pattern of a second layer on a substrate on which a first layer is formed, the second pattern region including a first pattern formed by light transmitted through a pattern formation region of an original and a second pattern region smaller than the first pattern region, the second pattern region including a second pattern formed by light transmitted through a partial region of the pattern formation region of the original , the method comprising:
in the first pattern region, a first alignment mark for aligning a pattern of the first pattern region in the first layer with a pattern of the first pattern region in the second layer, a second alignment mark for aligning a pattern of the second pattern region in the first layer with a pattern of the second pattern region in the second layer, and a third alignment mark for determining a positional deviation between the first pattern region and the second pattern region in the first layer,
a fourth alignment mark for aligning a pattern of the second pattern region in the first layer with a pattern of the second pattern region in the second layer, and a fifth alignment mark for determining a positional deviation between the first pattern region and the second pattern region in the first layer are formed in the second pattern region;
The exposure method includes:
a first detection step of detecting the first alignment mark;
a second detection step of simultaneously detecting the second alignment mark and the fourth alignment mark ;
a third detection step of detecting the third alignment mark and the fifth alignment mark;
an exposure step of controlling the alignment of the original and the substrate and exposing the substrate to light;
An exposure method characterized in that the exposure process controls the alignment of the original and the substrate for pattern formation in the second layer based on the results detected in the first detection process, the second detection process, and the third detection process . an exposure step of exposing a substrate by the exposure apparatus according to any one of claims 1 to 10;
a developing step of developing the substrate exposed in the exposure step,
A method for manufacturing an article, comprising the steps of: manufacturing an article from the substrate developed in the developing step;

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