Wafer exposure layout method
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- TAIWAN ASIA SEMICONDUCTOR CORPORATION
- Filing Date
- 2025-01-16
- Publication Date
- 2026-07-31
Smart Images
Figure 0007898554000001 
Figure 0007898554000002 
Figure 0007898554000003
Abstract
Description
Technical Field
[0001] The present invention relates to a wafer exposure layout method, and particularly to a wafer exposure layout method capable of improving the utilization rate of wafers.
Background Art
[0002] Conventional stepper exposure apparatuses can be applied to the exposure process of large-area wafers. The stepper exposure apparatus adopts a dynamic movement method of single-field exposure. As shown in FIG. 1, the stepper exposure apparatus first determines a plurality of regions Z1 to Zn on the wafer W, and then uses a photomask to expose a partial region of the wafer W corresponding to a single region Z1. When the exposure of the region Z1 is completed, the wafer W and the photomask are relatively moved, and the photomask exposes a partial region of the wafer corresponding to the next single region Z2. This operation is repeated until the exposure of all the set regions of the wafer is completed.
[0003] Taking the wafer W having hexagonal elements as an example, as shown in FIGS. 1 and 2, the conventional photomask Y is designed in a rectangular structure according to the region size. Inside the rectangular structure, each hexagonal unit corresponds to each hexagonal element. Since the sides of two adjacent regions (taking two adjacent regions Z1 and Z2 in the horizontal direction, or two adjacent regions Z1 and Z4 in the vertical direction as examples) are connected to each other, when sequentially exposing a plurality of regions Z1 to Zn using the photomask Y, alignment errors are likely to occur between two adjacent regions. Some hexagonal units in one region and some hexagonal units in another adjacent region (shown by the shaded part in FIG. 2) do not completely match. Therefore, some hexagonal units and the corresponding hexagonal elements are not completely exposed, which may lead to a decrease in the utilization rate of the wafer and cause losses.
[0004] Therefore, how to design a wafer exposure layout method that can improve the above problems is an issue worthy of research.
Summary of the Invention
[0005] The object of the present invention is to provide a wafer exposure layout method that can be applied to polygonal elements and can improve wafer utilization.
[0006] The wafer exposure layout method of the present invention performs step exposure on a wafer on which a plurality of polygonal elements have been formed in advance. To achieve the above objective, the wafer exposure layout method of the present invention includes the following steps: A plurality of linear exposure paths are determined on the wafer, parallel to each other and at equal intervals. Each linear exposure path includes a plurality of rectangular exposure regions arranged along a straight line, and a part of any one rectangular exposure region overlaps with another adjacent rectangular exposure region. Each rectangular exposure region covers a part of the wafer. A photomask is prepared. The photomask has a honeycomb structure composed of a plurality of regular hexagonal units, and uneven edges are formed on each side of the photomask. Any one of the regular hexagonal units corresponds to at least one of the plurality of polygonal elements. The photomask is moved on the wafer along each of the plurality of exposure paths. When moving the photomask along the exposure path, it is moved along each of the plurality of arranged rectangular exposure regions, thereby exposing the wafer. When the photomask moves to a first exposure position within a rectangular exposure region, each side of the photomask partially contacts each side of the rectangular exposure region, and at least one side of the photomask coincides with the side of the photomask when it moves to a second exposure position within another adjacent rectangular exposure region.
[0007] In embodiments of the present invention, each side of the photomask includes a plurality of protrusions and a plurality of recesses. When the photomask moves to a first exposure position in any of the rectangular exposure regions, the plurality of protrusions on at least one side of the photomask coincide with the plurality of recesses on the side of the photomask when it moves to a second exposure position in another adjacent rectangular exposure region, and the plurality of recesses on at least one side of the photomask coincide with the plurality of protrusions on the side of the photomask when it moves to a second exposure position in another adjacent rectangular exposure region.
[0008] In the embodiments of the present invention, a portion of the region extending inward from the short side of any rectangular exposure region in each exposure path overlaps with a portion of the region extending inward from the short side of another rectangular exposure region adjacent to it in the horizontal direction.
[0009] In the embodiments of the present invention, a portion of the region extending inward from the longer side of any rectangular exposure region in each exposure path overlaps with a portion of the region extending inward from the longer side of another rectangular exposure region in another vertically adjacent exposure path.
[0010] In embodiments of the present invention, a portion of the region extending inward from the corner between the long and short sides of any rectangular exposure region in each exposure path overlaps with a portion of the region extending inward from the corner between the long and short sides of another rectangular exposure region in another diagonally adjacent exposure path.
[0011] In embodiments of the present invention, when the photomask moves within any of the rectangular exposure regions, the position of any of the regular hexagonal units corresponds to the position of at least one of the multiple polygonal elements.
[0012] In the embodiments of the present invention, each regular hexagonal unit is composed of a plurality of polygonal subunits, and when the photomask moves within any of the rectangular exposure areas, the position of any of the polygonal subunits corresponds to the position of one of the plurality of polygonal elements.
[0013] In the embodiments of the present invention, each polygonal subunit is either an equilateral triangle or an isosceles trapezoid.
[0014] In the embodiments of the present invention, each polygonal element is an equilateral triangle, an isosceles trapezoid, or a regular hexagon.
[0015] In embodiments of the present invention, a plurality of regular hexagonal units form a plurality of rows of regular hexagonal unit groups, and the regular hexagonal unit groups in any row are arranged alternately with the regular hexagonal unit groups in adjacent rows, thereby forming a honeycomb structure.
[0016] The present invention further provides a photomask applicable to the wafer exposure layout method described above. The photomask has a honeycomb structure composed of a plurality of regular hexagonal units, with a recessed edge formed on each side of the photomask. Any regular hexagonal unit corresponds to at least one of a plurality of polygonal elements of the wafer. [Brief explanation of the drawing]
[0017] [Figure 1] A schematic diagram showing how a conventional stepper exposure system performs the wafer exposure process. [Figure 2] A schematic diagram showing the exposure state of two adjacent regions when a conventional stepper exposure system performs a wafer exposure process. [Figure 3] Flowchart of the wafer exposure layout method of the present invention [Figure 4] A schematic diagram showing multiple linear exposure paths determined by the wafer exposure layout method of the present invention. [Figure 5] A schematic diagram showing a photomask used in the wafer exposure layout method of the present invention. [Figure 6] A schematic diagram showing the trajectory of a photomask moving along each of multiple exposure paths on a wafer in the wafer exposure layout method of the present invention. [Figure 7] A schematic diagram showing the trajectory of a photomask within a single rectangular exposure region in the wafer exposure layout method of the present invention. [Figure 8] A schematic diagram showing the trajectory of a photomask moving between two horizontally adjacent rectangular exposure regions in the wafer exposure layout method of the present invention. [Figure 9] A schematic diagram showing the trajectory of a photomask moving between two vertically adjacent rectangular exposure regions in the wafer exposure layout method of the present invention. [Figure 10] A schematic diagram showing the trajectory of a photomask moving diagonally between two adjacent rectangular exposure regions in the wafer exposure layout method of the present invention. [Figure 11A]Schematic diagram showing another embodiment of a photomask used in the wafer exposure layout method of the present invention [Figure 11B] Schematic diagram showing yet another embodiment of a photomask used in the wafer exposure layout method of the present invention
Mode for Carrying Out the Invention
[0018] Each embodiment and example is merely illustrative and not limiting. After referring to this specification, those with ordinary knowledge can make other embodiments and examples without departing from the scope of the present invention. According to the following detailed description and claims, the features and advantages of the embodiments of the present invention will become clearer.
[0019] In this specification, the terms "one" or "a" are used to describe the units, elements, and assemblies described herein. This is for convenience and to give a general meaning to the scope of the present invention. Therefore, unless otherwise indicated, such descriptions are understood to include one or at least one, and the singular form also includes the plural form.
[0020] In this specification, ordinal terms such as "first" and "second" are mainly used to distinguish or refer to the same or similar components and structures, and do not necessarily mean the spatial or temporal ordering of these components and structures. It should be noted that in a specific situation or configuration, the ordinal terms can be used interchangeably without affecting the implementation of the present invention.
[0021] In this specification, the terms "including", "comprising", "having", "possessing", or other similar terms are for non-exclusive inclusion. For example, a component or structure including a plurality of elements is not limited only to the elements listed in this specification, and may include other elements specific to the component or structure that are not explicitly listed.
[0022] The wafer exposure layout method of the present invention is mainly applied to a stepper exposure apparatus, thereby performing step exposure on a wafer on which multiple polygonal elements have been formed in advance. The number of polygonal elements to be formed on the wafer can be determined in advance according to the demand. In the present invention, each polygonal element is an equilateral triangle, an isosceles trapezoid, or a regular hexagon, but the present invention is not limited to these. The explanation will be given with reference to Figures 3 to 5. Figure 3 is a flowchart of the wafer exposure layout method of the present invention. Figure 4 is a schematic diagram showing multiple linear exposure paths determined by the wafer exposure layout method of the present invention. Figure 5 is a schematic diagram showing a photomask used in the wafer exposure layout method of the present invention. As shown in Figure 3, the wafer exposure layout method of the present invention includes the following steps.
[0023] Step S1: Determine multiple linear exposure paths that are parallel to each other and equally spaced. Each linear exposure path contains multiple rectangular exposure regions aligned along a straight line. Part of any one rectangular exposure region overlaps with another adjacent rectangular exposure region. Each rectangular exposure region covers a portion of the wafer.
[0024] Since the total exposure area of the photomask for exposure is smaller than the total area of the wafer, when performing step exposure on a wafer, it is necessary to move the photomask step by step along the exposure path set on the wafer so that the range of movement of the photomask covers the total area of the wafer as much as possible. As shown in Figure 4, first, the present invention determines a plurality of linear exposure paths L1 to L9 for the wafer W to be exposed. These linear exposure paths L1 to L9 are arranged parallel to each other and at equal intervals. In practice, the number and spacing of the plurality of linear exposure paths L1 to L9 will vary depending on the total area of the wafer W and the total area of the photomask 10.
[0025] Each linear exposure path contains multiple rectangular exposure regions. These multiple rectangular exposure regions are aligned along a straight line and aligned laterally to one another. In Figure 4, for example, linear exposure path L1 contains multiple rectangular exposure regions A11 to A12 aligned along a straight line and aligned laterally to one another. For example, linear exposure path L2 contains multiple rectangular exposure regions A21 to A24 aligned along a straight line and aligned laterally to one another. The same applies to subsequent paths. Multiple rectangular exposure regions on different linear exposure paths are also aligned along a straight line perpendicular to the linear exposure path and aligned vertically to one another. For example, rectangular exposure regions A21 to A81 are aligned along a vertical straight line and aligned vertically to one another. In practice, the number and area of the multiple rectangular exposure regions will vary depending on the total area of the wafer W and the total area of the photomask 10.
[0026] Each rectangular exposure region covers a portion of the wafer W. When the photomask 10 moves into the target rectangular exposure region, the photomask 10 exposes an area of the portion of the wafer W. Each rectangular exposure region includes two long sides and two short sides. In this invention, a portion of any rectangular exposure region overlaps with another adjacent rectangular exposure region. "Adjacent" is defined as another rectangular exposure region that is periphery of any target rectangular exposure region and is in contact (at a point or line) with that target rectangular exposure region. The overlapping positions of two different rectangular exposure regions (for example, arranged along the same linear exposure path or arranged along different linear exposure paths) are also different. For example, two rectangular exposure regions may be adjacent horizontally, vertically, or diagonally.
[0027] In embodiments of the present invention, a portion of the region extending inward from the short side of any rectangular exposure region in each exposure path overlaps with a portion of the region extending inward from the short side of another rectangular exposure region adjacent in the horizontal direction. In other words, for the same exposure path, the region inside one of the short sides of any rectangular exposure region extends beyond the short side of another rectangular exposure region adjacent in the horizontal direction and enters that other rectangular exposure region. For example, this applies to the horizontally adjacent rectangular exposure regions A11 and A12 in the linear exposure path L1.
[0028] In embodiments of the present invention, a portion of the region extending inward from the longer side of any rectangular exposure region in each exposure path overlaps with a portion of the region extending inward from the longer side of another rectangular exposure region in another vertically adjacent exposure path. In other words, with respect to two adjacent different exposure paths, the region inside one of the longer sides of any rectangular exposure region extends beyond the longer side of another vertically adjacent rectangular exposure region and enters that other rectangular exposure region. For example, this applies to rectangular exposure region A11 of linear exposure path L1 and rectangular exposure region A22 of linear exposure path L2 which is vertically adjacent to it.
[0029] In embodiments of the present invention, a portion of the region extending inward from the corner between the long and short sides of any rectangular exposure region in each exposure path overlaps with a portion of the region extending inward from the corner between the long and short sides of another rectangular exposure region in another diagonally adjacent exposure path. In other words, with respect to two adjacent exposure paths, the region inside the corner between the long and short sides of any rectangular exposure region extends beyond the corner between the long and short sides of another diagonally adjacent rectangular exposure region and enters that other rectangular exposure region. For example, this applies to rectangular exposure region A11 of linear exposure path L1 and rectangular exposure region A21 of linear exposure path L2, which is diagonally adjacent to it.
[0030] Therefore, in the multiple linear exposure paths L1 to L9, the multiple rectangular exposure regions A11 to A92 partially overlap each other and are regularly arranged along the horizontal and vertical lines, so that the wafer W is closely covered by the multiple rectangular exposure regions A11 to A92.
[0031] Step S2: Prepare a photomask. The photomask is a honeycomb structure composed of multiple regular hexagonal units. Each side of the photomask has a concave edge. Each regular hexagonal unit corresponds to at least one of multiple polygonal elements.
[0032] After determining multiple linear exposure paths in step S1, the present invention then prepares a photomask 10 for exposing the wafer W. As shown in Figures 4 and 5, in this embodiment, the photomask 10 is a honeycomb structure composed of multiple regular hexagonal units 11. The shape and size of each regular hexagonal unit 11 are adapted to the shape and size of a single polygonal element of the wafer, or to the shape and size of a combination of multiple polygonal elements. The photomask 10 can completely fit within the rectangular exposure area. The photomask 10 is composed of the maximum number of regular hexagonal units 11, thereby covering as much of the area of the entire rectangular exposure area as possible.
[0033] In embodiments of the present invention, a plurality of regular hexagonal units 11 form a plurality of rows of regular hexagonal unit groups. A regular hexagonal unit group in any row is arranged alternately with a regular hexagonal unit group in an adjacent row, thereby forming a honeycomb structure. For example, as shown in Figure 5, each row of regular hexagonal unit groups is composed of six regular hexagonal units 11 arranged vertically. Sixteen rows of regular hexagonal unit groups are arranged alternately horizontally. The resulting honeycomb structure is confined to approximately the area of one designed rectangular exposure region. The number of regular hexagonal units 11 included in each row of regular hexagonal unit groups and the number of rows of regular hexagonal unit groups are not limited to those described above and can be changed according to the structural design and requirements.
[0034] Therefore, on each side of the photomask 10 (that is, the four sides of the photomask 10 that are not the two large exposure surfaces, but the top, bottom, left, and right sides, based on the viewpoint in Figure 5), a bumpy edge is formed by a combination of multiple regular hexagonal units 11. Here, a bumpy edge refers to the fact that each side of the photomask 10 forms a puzzle-like bumpy edge, and is not a straight edge.
[0035] More specifically, each side of the photomask 10 has multiple protrusions 12 and multiple recesses 13. The multiple protrusions 12 and multiple recesses 13 on each side are arranged in an approximately alternating and regular pattern. The protrusions 12 and recesses 13 are part of a regular hexagonal unit 11. Structurally, two sides of the photomask 10 (i.e., two long sides or two short sides) have protrusions 12 and recesses 13 of the same shape and size. The shape and size of the protrusions 12 are designed to match the shape and size of the recesses 13. Two adjacent sides of the photomask 10 (i.e., a long side and a short side that are adjacent and form a corner) have protrusions 12 and recesses 13 of different shapes and sizes.
[0036] Step S3: The photomask is moved along each of the multiple exposure paths on the wafer. As the photomask moves along the exposure path, it moves along each of the multiple rectangular exposure regions arranged in a row, thereby exposing the wafer.
[0037] After preparing the photomask 10 in step S2, in this invention, the photomask 10 is moved sequentially along one of a plurality of exposure paths relative to the wafer W, thereby exposing the wafer W. When the photomask 10 moves along the exposure path, it moves sequentially along one of a plurality of rectangular exposure regions arranged along that exposure path, thereby performing step exposure.
[0038] The explanation will be given with reference to Figures 4 and 6 to 10. Figure 6 is a schematic diagram showing the trajectory of a photomask moving along each of a plurality of exposure paths on a wafer in the wafer exposure layout method of the present invention. Figure 7 is a schematic diagram showing the trajectory of a photomask within one rectangular exposure region in the wafer exposure layout method of the present invention. Figure 8 is a schematic diagram showing the trajectory of a photomask moving between two horizontally adjacent rectangular exposure regions in the wafer exposure layout method of the present invention. Figure 9 is a schematic diagram showing the trajectory of a photomask moving between two vertically adjacent rectangular exposure regions in the wafer exposure layout method of the present invention. Figure 10 is a schematic diagram showing the trajectory of a photomask moving between two diagonally adjacent rectangular exposure regions in the wafer exposure layout method of the present invention. As shown in Figures 4 and 6, it is assumed that nine linear exposure paths L1 to L9 parallel to each other are determined for the wafer W. Each linear exposure path includes a plurality of adjacent rectangular exposure regions. The photomask 10 first moves along the first linear exposure path L1 from the first rectangular exposure region A11 to the second rectangular exposure region A12, and then moves along the second linear exposure path L2 adjacent to the first linear exposure path L1 from the first rectangular exposure region A21 to the fourth rectangular exposure region A24. The same movement is repeated from the third linear exposure path to the eighth linear exposure path, and finally, it moves along the ninth linear exposure path L9 to the second rectangular exposure region A92.
[0039] As shown in Figures 6 and 7, in the present invention, when the photomask 10 moves within any of the rectangular exposure areas, the position of each regular hexagonal unit 11 of the photomask 10 corresponds to the position of at least one of a plurality of polygonal elements. Since the shape and size of each regular hexagonal unit 11 conform to the shape and size of one polygonal element or a combination of multiple polygonal elements of the wafer W, each regular hexagonal unit 11 of the photomask 10 can expose one polygonal element or a plurality of polygonal elements.
[0040] In this invention, when the photomask 10 moves into any of the rectangular exposure regions, the photomask 10, once fully inside the rectangular exposure region, has the maximum number of regular hexagonal units 11, so that each side of the photomask 10 partially contacts each side of the rectangular exposure region. As shown in Figure 7, for example, the ends of each projection 12 on each long side of the photomask 10 contact and overlap with the long side of the rectangular exposure region. Each recess 13 on each long side of the photomask 10 is formed between the projection 12 and the long side of the rectangular exposure region. Similarly, the ends of each projection 12 on each short side of the photomask 10 contact and overlap with the short side of the rectangular exposure region. Each recess 13 on each short side of the photomask 10 is formed between the projection 12 and the short side of the rectangular exposure region.
[0041] When the photomask 10 moves along any linear exposure path to an exposure position within any rectangular exposure region, at least one side of the photomask 10 coincides with the side of the photomask 10 when it moves to an exposure position within another adjacent rectangular exposure region. As shown in Figures 6 and 8, for example, when the photomask 10 moves along the linear exposure path L1 into the rectangular exposure region A11, the photomask 10 is defined as being in the first exposure position P1. The outer contour of this first exposure position P1 corresponds to the uneven edges formed on each side of the photomask 10. Next, the photomask 10 at the first exposure position P1 exposes a portion of the wafer W. After exposure at the first exposure position P1 is complete, the photomask 10 moves laterally into another adjacent rectangular exposure region A12 along the linear exposure path L1. At this point, the photomask 10 is defined as being in the second exposure position P2. The outer contour of this second exposure position similarly corresponds to the uneven edges formed on each side of the photomask 10.
[0042] In this embodiment, a portion of the rectangular exposure area A11 extending inward from its short side overlaps with a portion of the laterally adjacent rectangular exposure area A12 extending inward from its short side. The laterally length of the aforementioned portion is equal to the laterally length of each protrusion 12 formed on the short side of the photomask 10 and the laterally length of each recess 13. The uneven edges on the short side of the photomask 10 at the first exposure position P1 coincide with the uneven edges on the short side of the photomask 10 at the second exposure position P2. More specifically, when the photomask 10 is at the first exposure position P1 of the rectangular exposure area A11, the multiple protrusions 12 on the short side of the photomask 10 coincide with the multiple recesses 13 on the short side of the photomask 10 when it moves to the second exposure position P2 in the laterally adjacent rectangular exposure area A12. Multiple recesses 13 on the short side of the photomask 10 at the first exposure position P1 coincide with multiple protrusions 12 on the short side of the photomask 10 when it moves to the second exposure position P2 in the laterally adjacent rectangular exposure region A12. The same applies when the photomask 10 subsequently moves between two other laterally adjacent rectangular exposure regions on the linear exposure path. Therefore, when the photomask 10 performs step-movement exposure along the linear exposure path, it is possible to ensure that two laterally adjacent rectangular exposure regions perfectly coincide and to avoid the occurrence of exposure gaps.
[0043] As shown in Figures 6 and 9, for example, suppose the photomask 10 moves along a linear exposure path L1 into a rectangular exposure area A11. At this time, the photomask 10 is defined as being in the first exposure position P1. The outer contour of this first exposure position P1 corresponds to the uneven edges formed on each side of the photomask 10. After the photomask 10 moves to the last rectangular exposure area A12 on its linear exposure path L1, the photomask 10 performs step-movement exposure along another linear exposure path L2 adjacent to the linear exposure path L1. When the photomask 10 moves along the linear exposure path L2 into a vertically adjacent rectangular exposure area A22, the photomask 10 is defined as being in the second exposure position P2. The outer contour of the second exposure position P2 similarly corresponds to the uneven edges formed on each side of the photomask 10.
[0044] In this embodiment, a portion of the rectangular exposure area A11 extending inward from its long side overlaps with a portion of the rectangular exposure area A22 of another linear exposure path L2 that is adjacent in the vertical direction and extends inward from its long side. The vertical length of the aforementioned portion of the area is equal to the vertical length of each protrusion 12 formed on the long side of the photomask 10 and the vertical length of each recess 13. The uneven edges formed on the long side of the photomask 10 at the first exposure position P1 coincide with the uneven edges formed on the long side of the photomask 10 when it is at the second exposure position P2. More specifically, when the photomask 10 is at the first exposure position P1 of the rectangular exposure area A11, the multiple protrusions 12 on the long side of the photomask 10 coincide with the multiple recesses 13 on the long side of the photomask 10 when it moves to the second exposure position P2 of the vertically adjacent rectangular exposure area A22. The multiple recesses 13 on the long side of the photomask 10 at the first exposure position P1 coincide with the multiple protrusions 12 on the long side of the photomask 10 when it moves to the second exposure position P2 of the vertically adjacent rectangular exposure region A22. The same applies when the photomask 10 subsequently moves between two other rectangular exposure regions in a vertically adjacent linear exposure path. Therefore, when the photomask 10 performs step-movement exposure along a vertically adjacent linear exposure path, it is possible to ensure that the two vertically adjacent rectangular exposure regions perfectly coincide and to avoid the occurrence of exposure gaps.
[0045] As shown in Figures 6 and 10, for example, when the photomask 10 moves along a linear exposure path L1 into a rectangular exposure area A11, the photomask 10 is defined as being at a first exposure position P1. The outer contour of this first exposure position P1 corresponds to the uneven edges formed on each side of the photomask 10. After the photomask 10 moves to the last rectangular exposure area A12 on its linear exposure path L1, the photomask 10 performs step-movement exposure along another linear exposure path L2 adjacent to that linear exposure path L1. When the photomask 10 moves diagonally adjacent to another rectangular exposure area A21 along the linear exposure path L2, the photomask 10 is defined as being at a second exposure position P2. The outer contour of the second exposure position P2 similarly corresponds to the uneven edges formed on each side of the photomask 10.
[0046] In this embodiment, a portion of the rectangular exposure area A11 extending inward from the corner between the long and short sides overlaps with a portion of the rectangular exposure area A21 of another diagonally adjacent linear exposure path L2 extending inward from the corner between the long and short sides. The lateral length of the aforementioned portion of the area is equal to the lateral length of each protrusion 12 formed on the short side of the photomask 10 and the lateral length of each recess 13. The vertical length of the aforementioned portion of the area is equal to the vertical length of each protrusion 12 formed on the long side of the photomask 10 and the vertical length of each recess 13. The edge formed at the corner between the long and short sides of the photomask 10 at the first exposure position P1 coincides with the edge formed at the corner between the long and short sides of the photomask 10 when it is at the second exposure position P2. More specifically, when the photomask 10 is at the first exposure position P1 of the rectangular exposure region A11, the recessed portion 13 at the corner between the long and short sides of the photomask 10 coincides with a portion of the protruding portion 12 at the corner between the long and short sides of the photomask 10 when it moves to the second exposure position P2 of the diagonally adjacent rectangular exposure region A21. The same applies when the photomask 10 subsequently moves between two other rectangular exposure regions in a diagonally adjacent linear exposure path. Therefore, when the photomask 10 performs step-movement exposure along an adjacent linear exposure path, it is possible to ensure that the diagonally adjacent rectangular exposure regions perfectly coincide and to avoid the occurrence of exposure gaps.
[0047] Therefore, the wafer exposure layout method of the present invention uses a photomask with a special structural design and multiple rectangular exposure regions aligned along a straight line and partially overlapping, to move the photomask and wafer in steps along multiple linear exposure paths. The shapes of the photomasks match each other in adjacent rectangular exposure regions, thereby maximizing the overall wafer utilization rate. Compared to conventional stepper exposure apparatuses, the wafer exposure layout method of the present invention can avoid layout errors, incomplete exposure of elements, and loss of wafer utilization rate that tend to occur when the photomask moves between adjacent rectangular exposure regions.
[0048] As shown in Figure 5, the present invention provides a photomask 10 applicable to the wafer exposure layout method described above. The photomask 10 is a honeycomb structure composed of a plurality of regular hexagonal units 11. A raised and recessed edge is formed on each side of the photomask 10. Each regular hexagonal unit 11 corresponds to at least one of a plurality of polygonal elements. The plurality of regular hexagonal units 11 form a plurality of rows of regular hexagonal unit groups arranged in the vertical direction. The regular hexagonal unit groups in any row are arranged alternately with the regular hexagonal unit groups in another adjacent row, thereby forming a honeycomb structure.
[0049] The invention will be described with reference to Figures 11A and 11B. Figure 11A is a schematic diagram showing another embodiment of the photomask to which the present invention applies. Figure 11B is a schematic diagram showing yet another embodiment of the photomask to which the present invention applies. As shown in Figures 11A and 11B, in other embodiments of the photomask of the present invention, each regular hexagonal unit is designed to consist of multiple polygonal subunits to accommodate the different shapes and sizes of multiple polygonal elements pre-formed on the wafer. The shape and size of each polygonal subunit are adapted to the shape and size of the polygonal elements on the wafer.
[0050] For example, as shown in Figure 11A, each regular hexagonal unit 11a of the photomask 10a is composed of two polygonal subunits 111. Each polygonal subunit 111 is an isosceles trapezoid. Each polygonal subunit 111 corresponds to one trapezoidal element. When the photomask is moved within any rectangular exposure area, the position of each polygonal subunit 111 corresponds to the position of one trapezoidal element.
[0051] For example, as shown in Figure 11B, each regular hexagonal unit 11b of the photomask 10b is composed of six polygonal subunits 112. Each polygonal subunit 112 is an equilateral triangle. Each polygonal subunit 112 corresponds to one equilateral triangle element. When the photomask is moved within any rectangular exposure area, the position of each polygonal subunit 112 corresponds to the position of one equilateral triangle element.
[0052] The embodiments described above are illustrative and not intended to limit the embodiments or uses of the present invention. Furthermore, while the embodiments described above show at least one exemplary example, it should be understood that numerous variations of the invention are possible. Also, the embodiments described herein are not intended to limit the claims, uses, or configurations in any way. Rather, the embodiments described above provide a guide for a person ordinary skill in the art to carry out one or more embodiments. Furthermore, changes can be made to the function and arrangement of the elements without departing from the claims, and the claims include all known and foreseeable equivalents at the time of filing of this patent application. [Explanation of symbols]
[0053] 10, 10a, 10b Photomasks 11, 11a, 11b Regular hexagonal unit 111, 112 Polygonal subunits 12 Protrusion 13 recess A11~A92 Rectangular exposure area L1~L9 Linear exposure path P1 First exposure position P2 Second exposure position W wafer S1~S3 Steps Y Photomask Z1~Zn area
Claims
1. A wafer exposure layout method for performing step exposure on a wafer on which multiple polygonal elements have been formed in advance, A plurality of linear exposure paths are determined on the wafer, parallel to each other and equally spaced, each linear exposure path includes a plurality of rectangular exposure regions aligned along a straight line, a portion of any one of the rectangular exposure regions overlaps with another adjacent rectangular exposure region, and each rectangular exposure region covers a portion of the wafer. A photomask is prepared, and the photomask has a honeycomb structure composed of a plurality of regular hexagonal units, with uneven edges formed on each side of the photomask, and each of the regular hexagonal units corresponds to at least one of the plurality of polygonal elements. The photomask is moved along each of the multiple exposure paths on the wafer, and as the photomask moves along any of the exposure paths, it moves along each of the multiple rectangular exposure regions arranged in a row, thereby exposing the wafer. When the photomask moves to a first exposure position within any of the rectangular exposure regions, each side of the photomask partially contacts each side of the rectangular exposure region, and at least one side of the photomask coincides with the side of the photomask when it moves to a second exposure position within another adjacent rectangular exposure region. Includes steps, The number of regular hexagonal units forming each of the opposing pairs of sides of the aforementioned photomask is the same. Each side of the photomask includes a plurality of protrusions and a plurality of recesses, When the photomask moves to the first exposure position within any of the rectangular exposure regions, the multiple protrusions on at least one side of the photomask align with the multiple recesses on the side of the photomask when it moves to the second exposure position within another adjacent rectangular exposure region. A wafer exposure layout method characterized in that a plurality of recesses on at least one side of the photomask coincide with a plurality of protrusions on the side of the photomask when moved to a second exposure position in another adjacent rectangular exposure region.
2. The wafer exposure layout method according to claim 1, characterized in that a portion of the region extending inward from the short side of any of the rectangular exposure regions in each exposure path overlaps with a portion of the region extending inward from the short side of another rectangular exposure region adjacent to it in the lateral direction.
3. The wafer exposure layout method according to claim 1, characterized in that a portion of the region extending inward from the long side of any of the rectangular exposure regions in each of the exposure paths overlaps with a portion of the region extending inward from the long side of another rectangular exposure region in another exposure path adjacent in the vertical direction.
4. The wafer exposure layout method according to claim 1, characterized in that a portion of the region extending inward from the corner between the long side and short side of any of the rectangular exposure regions in each of the exposure paths overlaps with a portion of the region extending inward from the corner between the long side and short side of another rectangular exposure region in another exposure path that is diagonally adjacent.
5. The wafer exposure layout method according to claim 1, characterized in that when the photomask moves into any of the rectangular exposure regions, the position of any of the regular hexagonal units corresponds to the position of at least one of the plurality of polygonal elements.
6. Each of the aforementioned regular hexagonal units is composed of multiple polygonal subunits. The wafer exposure layout method according to claim 1, characterized in that when the photomask moves into any of the rectangular exposure regions, the position of any of the polygonal subunits corresponds to the position of one of the plurality of polygonal elements.
7. The wafer exposure layout method according to claim 6, characterized in that each of the aforementioned polygonal subunits is an equilateral triangle or an isosceles trapezoid.
8. The wafer exposure layout method according to claim 1, characterized in that each of the aforementioned polygonal elements is an equilateral triangle, an isosceles trapezoid, or a regular hexagon.
9. The aforementioned plurality of regular hexagonal units form a group of multiple rows of regular hexagonal units. The wafer exposure layout method according to claim 1, characterized in that the regular hexagonal unit groups in any of the columns are arranged alternately with the regular hexagonal unit groups in another adjacent column, thereby forming the honeycomb structure.
10. A photomask applicable to the wafer exposure layout method according to any one of claims 1 to 9, The aforementioned photomask has a honeycomb structure composed of multiple regular hexagonal units. Each side of the aforementioned photomask has a recessed edge formed thereon. A photomask in which any of the aforementioned hexagonal units corresponds to at least one of the plurality of polygonal elements of the wafer.