CN111766765A - Alignment mark - Google Patents
Alignment mark Download PDFInfo
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- CN111766765A CN111766765A CN202010686298.1A CN202010686298A CN111766765A CN 111766765 A CN111766765 A CN 111766765A CN 202010686298 A CN202010686298 A CN 202010686298A CN 111766765 A CN111766765 A CN 111766765A
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- alignment
- alignment mark
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- diffracted light
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
- G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
- G03F9/7073—Alignment marks and their environment
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
- G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
- G03F9/7073—Alignment marks and their environment
- G03F9/7076—Mark details, e.g. phase grating mark, temporary mark
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F9/00—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically
- G03F9/70—Registration or positioning of originals, masks, frames, photographic sheets or textured or patterned surfaces, e.g. automatically for microlithography
- G03F9/7073—Alignment marks and their environment
- G03F9/708—Mark formation
Abstract
The invention provides an alignment mark, which comprises at least one alignment mark unit, wherein each alignment mark unit comprises a plurality of alignment segmentation sections arranged along a first direction, each alignment segmentation section is arranged into a first graph structure or a second graph structure, and the first graph structure and the second graph structure are one of a groove structure and a protrusion structure. The plurality of alignment segments can generate a plurality of different orders of diffracted light in response to incident light, and the intensity of the 0 < th > order diffracted light is not greater than 10, and the intensity of the 3 < rd > order diffracted light is not less than 50.
Description
Technical Field
The invention relates to the field of integrated circuit manufacturing, in particular to an alignment mark.
Background
Alignment marks (alignment marks) play a very important role in semiconductor processing. In the wafer (wafer) manufacturing process, in order to enable the pattern on the photomask (also called as a reticle) to be correctly transferred onto the wafer, the key step is the alignment between the photomask and the wafer, and especially under the condition that the semiconductor process is becoming more mature, the requirement on the accuracy of the alignment mark becomes stricter.
When light enters the alignment mark, different orders of diffraction light with different intensities (wafer quality) can be generated at different angles by the light responding to the incident light, the different orders of diffraction light are separated through a specific optical structure, and the alignment of the photomask and the wafer is realized by the specific orders of diffraction light. Although the higher order diffracted light has better accuracy for aligning the photomask and the wafer, the 0 th order diffracted light has stronger energy, so that the contrast of other higher order diffracted light (such as the 3 rd order diffracted light) is affected and reduced, and the alignment accuracy is reduced. Therefore, it is necessary to provide an alignment mark to solve the problems of the prior art.
Disclosure of Invention
The invention aims to provide an alignment mark to improve the alignment precision of a photomask and a wafer.
In order to achieve the above object, a first aspect of the present invention provides an alignment mark comprising:
at least one alignment mark unit, each alignment mark unit comprising a plurality of alignment segments arranged along a first direction, each alignment segment being arranged as a first pattern structure or a second pattern structure, and the first pattern structure and the second pattern structure being one of a groove structure and a protrusion structure;
the plurality of alignment segments can generate a plurality of different orders of diffracted light in response to incident light, the intensity of the 0 th order diffracted light is not more than 10, and the intensity of the 3 rd order diffracted light is not less than 50.
Further, the plurality of alignment segments has 18 alignment segments.
Further, each alignment segment has a width along the first direction of about 0.88 microns or about 0.97 microns.
Further, the 1st, 2nd, 6 th, 7 th, 12 th, 13 th, 14 th, 17 th, 18 th alignment segment is the first pattern structure, and the 3 rd, 4 th, 5 th, 8 th, 9 th, 10 th, 11 th, 15 th, 16 th alignment segment is the second pattern structure, wherein the 1st to 18 th alignment segments are alignment segments arranged along the first direction in sequence.
Further, the 1st, 2nd, 3 rd, 6 th, 7 th, 12 th, 13 th, 17 th, 18 th alignment segment is the first pattern structure, and the 4 th, 5 th, 8 th, 9 th, 10 th, 11 th, 14 th, 15 th, 16 th alignment segment is the second pattern structure, wherein the 1st to 18 th alignment segments are alignment segments arranged along the first direction in sequence.
Further, the 1st, 2nd, 4 th, 6 th, 7 th, 12 th, 13 th, 17 th, 18 th alignment segment is the first pattern structure, and the 3 rd, 5 th, 8 th, 9 th, 10 th, 11 th, 14 th, 15 th, 16 th alignment segment is the second pattern structure, wherein the 1st to 18 th alignment segments are alignment segments arranged along the first direction in sequence.
Further, the 1st, 2nd, 6 th, 7 th, 12 th, 13 th, 17 th, and 18 th alignment segments are the first pattern structure, and the 3 rd, 4 th, 5 th, 8 th, 9 th, 10 th, 11 th, 14 th, 15 th, and 16 th alignment segments are the second pattern structure, wherein the 1st to 18 th alignment segments are alignment segments arranged along the first direction in sequence.
Further, the plurality of alignment segments has 12 alignment segments.
Further, each alignment segment has a width along the first direction of about 1.33 microns or about 1.46 microns.
Further, the 1st, 2nd, 3 rd, 5 th, 6 th, 10 th alignment segment is the first pattern structure, and the 4 th, 7 th, 8 th, 9 th, 11 th, 12 th alignment segment is the second pattern structure, wherein the 1st to 12 th alignment segments are sequentially alignment segments arranged along the first direction.
Further, the 1st, 2nd, 5 th, 6 th and 10 th alignment segments are the first pattern structure, and the 3 rd, 4 th, 7 th, 8 th, 9 th, 11 th and 12 th alignment segments are the second pattern structure, wherein the 1st to 12 th alignment segments are sequentially alignment segments arranged along the first direction.
Further, the 1st, 2nd, 3 rd, 6 th and 10 th alignment segments are the first pattern structure, and the 4 th, 5 th, 7 th, 8 th, 9 th, 11 th and 12 th alignment segments are the second pattern structure, wherein the 1st to 12 th alignment segments are sequentially alignment segments arranged along the first direction.
Further, the first pattern structure and the second pattern structure of the alignment segment extend in a second direction intersecting the first direction, and the alignment mark units are repeatedly laid along the first direction to obtain the plurality of orders of diffracted light in the first direction.
Further, the first pattern structure and the second pattern structure of the alignment segment extend along the first direction, and the alignment mark units are repeatedly laid along a second direction intersecting the first direction to obtain the plurality of orders of diffracted light in the second direction.
Further, the alignment mark is formed by combining two identical and oppositely arranged first and second composite alignment marks, each of which comprises the at least one alignment mark unit, so as to obtain the multiple orders of diffracted light in the first direction and a second direction intersecting the first direction at the same time.
Further, the arrangement direction of the first composite alignment mark is complementary to the arrangement direction of the second composite alignment mark, and the end of each alignment segment in the alignment mark unit in the first composite alignment mark is correspondingly connected to the end of each alignment segment in the alignment mark unit in the second composite alignment mark.
By the arrangement of the alignment mark unit provided by the invention, when the alignment of the photomask plate and the wafer is carried out, the influence of the 0 th order diffraction light can be avoided, the contrast of the higher order diffraction light is reduced, and the intensity of the 3 rd order diffraction light is remarkably improved, so that when the 3 rd order diffraction light is used as an alignment signal, the alignment speed and the alignment precision of the photomask plate and the wafer can be improved. As can be seen, the invention has substantial and highly outstanding efficacy and very obvious advantages.
Drawings
The technical solution and other advantages of the present invention will become apparent from the following detailed description of specific embodiments of the present invention, which is to be read in connection with the accompanying drawings.
FIG. 1 is a diagram of a first standard alignment mark.
FIG. 2 is a diagram of a second standard alignment mark.
Fig. 3 is a schematic diagram of an alignment mark according to a first embodiment of the present invention.
Fig. 4 is a schematic diagram of an alignment mark unit according to a first sub-embodiment of the present invention.
Fig. 5 is a schematic diagram of an alignment mark unit according to a second sub-embodiment of the present invention.
Fig. 6 is a schematic diagram of an alignment mark unit according to a third sub-embodiment of the present invention.
Fig. 7 is a schematic diagram of an alignment mark unit according to a fourth sub-embodiment of the present invention.
Fig. 8 is a schematic diagram of an alignment mark unit according to a fifth sub-embodiment of the present invention.
Fig. 9 is a schematic diagram of an alignment mark unit according to a sixth sub-embodiment of the present invention.
Fig. 10 is a schematic diagram of an alignment mark unit according to a seventh sub-embodiment of the present invention.
Fig. 11 is a diagram illustrating an alignment mark according to a second embodiment of the present invention.
Fig. 12 is a schematic diagram of an alignment mark according to a third embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the particular embodiments described herein are illustrative only, and that the word "embodiment" as used in the description of the invention is intended to serve as an example, instance, or illustration, and is not intended to limit the invention.
In the photolithography process, the alignment system of the photolithography machine aligns the photomask and the wafer before performing the photolithography process. Further, the alignment process is to perform coarse alignment (coarse alignment) and then fine alignment (fine alignment), and two coarse alignment marks are usually only needed when performing the coarse alignment, specifically two wafer-level-sized marks, which may be disposed at the lower left and upper right of the wafer in one embodiment. Fine alignment is typically performed using a plurality of fine alignment marks disposed on scribe lines (scribes line) for positioning so that the alignment system can calculate the exact position at the time of exposure. Because the alignment method of the lithography machine is to make light (mostly adopting laser beam) incident on the coarse alignment mark or the fine alignment mark on the wafer, the light (such as reflected light) responding to the incident light can generate a plurality of diffracted lights of different orders, and the detector on the alignment system receives the diffracted lights of specific orders as the alignment signal, thereby realizing the alignment of the optical mask plate and the wafer.
Referring to fig. 1, fig. 1 is a schematic diagram of a first standard alignment mark 51. In order to generate different orders of diffracted light for alignment, the first standard alignment mark unit 511 in the first standard alignment mark 51 is designed to have 2 alignment segments (segmentation), specifically, the first and second alignment segments 511a/511b are respectively set as the first pattern structure 1st and the second pattern structure 2nd, at this time, the first standard alignment mark 51 forms a grating-like structure, when light is incident on the first alignment mark 51, light (e.g. reflected light) responding to the incident light can generate different orders of diffracted light, and alignment between the light mask plate and the wafer is realized according to the specific orders of diffracted light (e.g. 2nd order diffracted light) as an alignment signal. It is understood that since the diffracted light generated by the first standard alignment mark unit 511 may only have the lower order diffracted light of 0 th order, 1st order, 2nd order, etc., or although the higher order diffracted light (e.g., 3 rd to 7 th order diffracted light) may be generated, the higher order diffracted light has too low intensity to be used as an alignment signal, so the above-mentioned is, for example, the 2nd order diffracted light having higher intensity than the higher order diffracted light as an alignment signal, but this is merely an exemplary illustration and should not be construed as a limitation of the present invention. Preferably, the widths of the first pattern structure 1st and the second pattern structure 2nd in the first alignment mark unit 511 are both 8.8 micrometers, that is, the first alignment mark unit 511 is repeatedly arranged at a period of 17.6 micrometers to form the first standard alignment mark 51.
It is understood that the 0 th order diffraction light refers to the center-located diffraction light generated spectrally after light passes through the quasi-alignment marks like a grating structure, and the higher order or higher order diffraction light (including the 1st order diffraction light and the diffraction light greater than the order) than the 0 th order diffraction light is the diffraction light located around the 0 th order diffraction light generated spectrally, and the higher order of the diffraction light farther from the 0 th order diffraction light.
It is understood that the first pattern structure 1st and the second pattern structure 2nd may be formed by a photolithography process, but the present invention is not particularly limited thereto. In one embodiment, the first pattern structure 1st is a groove structure, and the second pattern structure 2nd is a protrusion structure. In another embodiment, the first pattern structure 1st is a protrusion structure, and the second pattern structure 2nd is a groove structure.
Referring to fig. 2, fig. 2 is a schematic diagram of the second standard alignment mark 52. In the case of smaller and smaller feature sizes, in order to align the photomask plate and the wafer more accurately, it is necessary to generate and use high-order diffracted light (e.g., 3 rd to 7 th order diffracted light) to improve the alignment accuracy. Generally, the order represents the optical order of the diffracted light, with higher orders corresponding to higher orders of the diffracted light. Accordingly, the second standard alignment mark unit 521 in the second standard alignment mark 52 may be designed to have 4 alignment segments, specifically, the 1st and 3 rd alignment segments 521a/521c are set as the first pattern structure 1st, the 2nd and 4 th alignment segments 521b/521d are set as the second pattern structure 2nd, and the second standard alignment mark 52 forms a grating-like structure, when light is incident on the second alignment mark 52, since the second standard alignment mark unit 521 has a finer alignment segment than the first standard alignment mark unit 511, it is possible to generate higher-order diffracted light or higher-order diffracted light with higher intensity, and alignment of the light mask plate with the wafer is achieved according to a specific-order diffracted light (e.g., 3 rd-order diffracted light) therein as an alignment signal. Preferably, the 1st to 3 rd alignment segments 521a/521b/521c in the second standard alignment mark unit 521 have a width of 8 micrometers (average to a width of about 2.66 micrometers) and the 4 th alignment segment 521d has a width of 9.6 micrometers, i.e., the second alignment mark unit 521 is repeatedly arranged at a period of 17.6 micrometers to form the second alignment mark 52.
Referring to table 1, table 1 shows a plurality of diffracted lights with different orders and different intensities generated by the second standard alignment mark unit 521 according to fig. 2.
| Order/intensity of diffracted light | Stage 0 | Stage 1 | Stage 2 | Stage 3 | Stage 4 | Stage 5 | Stage 6 | Stage 7 |
| Second standard |
27.4 | 25 | 18.4 | 44.4 | 4.7 | 1 | 0 | 0.5 |
TABLE 1
In general, the intensity of the diffracted light can be used as an effective alignment signal as long as it is greater than 1, and thus the 0 th to 5 th order diffracted lights can be used as an alignment signal in the second standard alignment mark unit 521. However, since the 0 th order diffracted light has intensity compared to that of the 1st, 2nd, 4 th and 5 th order diffracted lights, the diffracted lights of these orders are affected to reduce contrast in performing alignment, and even the 3 rd order diffracted light having intensity stronger than that of the 0 th order diffracted light is affected to reduce contrast in alignment, thereby reducing alignment accuracy. Although more precise alignment can be achieved by using higher order diffracted light, the intensity of diffracted light used as an alignment signal is relatively large or not strong enough compared to the intensity of diffracted light of other orders, which is susceptible to influence and reduces the alignment contrast. Therefore, the focus of the present invention is to provide an alignment mark having the effects of reducing the intensity of the 0 th order diffracted light and increasing the intensity of the 3 rd order diffracted light, so as to improve the alignment performance when the 3 rd order diffracted light is used as the alignment signal.
In one embodiment, the intensity of the diffracted light can be expressed by Wafer Quality (WQ), and the higher the wafer quality of the diffracted light, the stronger the intensity of the diffracted light, which is more suitable for being used as the alignment signal.
Referring to fig. 3 in combination with fig. 4 to 10, fig. 3 is a schematic diagram of an alignment mark 61/62/63/64/65/66/67 according to a first embodiment of the present invention, and fig. 4 to 10 are schematic diagrams of an alignment mark unit 611/621/631/641/651/661/671 according to first to seventh sub-embodiments of the present invention. In order to solve the above technical problem, each alignment mark provided according to the first embodiment of the present invention includes at least one alignment mark unit, that is, according to the first sub-embodiment of the present invention, the alignment mark 61 includes at least one alignment mark unit 611; according to the second sub-embodiment of the present invention, the alignment mark 62 includes at least one alignment mark unit 621; according to the third sub-embodiment of the present invention, the alignment mark 63 includes at least one alignment mark unit 631; according to the fourth sub-embodiment of the present invention, the alignment mark 64 includes at least one alignment mark unit 641; according to the fifth sub-embodiment of the present invention, the alignment mark 65 includes at least one alignment mark unit 651; according to the sixth sub-embodiment of the present invention, the alignment mark 66 includes at least one alignment mark unit 661; according to the seventh sub-embodiment of the present invention, the alignment mark 67 includes at least one alignment mark unit 671. And, each alignment mark unit includes a plurality of alignment segments arranged along the first direction (e.g., X direction in the figure), i.e., the alignment mark unit 611 includes a plurality of alignment segments 611a-611r, the alignment mark unit 621 includes a plurality of alignment segments 621a-621r, the alignment mark unit 631 includes a plurality of alignment segments 631a-631r, the alignment mark unit 641 includes a plurality of alignment segments 641a-641r, the alignment mark unit 651 includes a plurality of alignment segments 651a-6511, the alignment mark unit 661 includes a plurality of alignment segments 661a-6611, and the alignment mark unit 671 includes a plurality of alignment segments 671 a-6711. Each alignment segment is provided as a first pattern structure 1st or a second pattern structure 2nd, and the first pattern structure 1st and the second pattern structure 2nd may be a groove structure or a protrusion structure. Preferably, the width D of the alignment mark cells 611/621/631/641/651/661/671 along the first direction may be 16 micrometers or 17.6 micrometers, that is, the alignment mark cells 611/621/631/641/651/661/671 are repeatedly arranged at a period of 16 micrometers or 17.6 micrometers to form the alignment mark 61/62/63/64/65/66/67. Further, in the first sub-embodiment to the fourth sub-embodiment, each of the alignment segments has a width along the first direction of about 0.88 microns or 0.97 microns; in the fifth sub-embodiment to the seventh sub-embodiment, each of the alignment segments has a width along the first direction of about 1.33 microns or about 1.46 microns.
It is to be understood that the width D may be any value other than 16 microns or 17.6 microns as described above, for example, any value between 1 micron and 100 microns, and should not be construed as limiting the invention.
Referring to table 2, table 2 shows the results of the diffraction intensities of each order obtained by the alignment mark unit 611/621/631/641/651/661/671 according to various embodiments of the present invention after actual measurement.
| Order/intensity of diffracted light | Stage 0 | Stage 1 | Stage 2 | Stage 3 | Stage 4 | Stage 5 | Stage 6 | Stage 7 |
| |
0 | 12 | 0 | 77.8 | 0 | 9.4 | 0 | 7.2 |
| |
0 | 18.8 | 4.8 | 52.8 | 10 | 12.2 | 6.3 | 1 |
| |
0 | 15.6 | 1.4 | 52.8 | 4.3 | 1.4 | 6.3 | 11.2 |
| |
3 | 9 | 2.9 | 75 | 2.6 | 7 | 2 | 5.4 |
| |
0 | 26.7 | 0 | 55.6 | 0 | 15 | 0 | 7.6 |
| |
6.9 | 6.7 | 6.2 | 72.3 | 4.7 | 3.7 | 2.8 | 1.9 |
| |
6.9 | 20 | 6.2 | 50 | 4.7 | 11.2 | 2.8 | 5.7 |
TABLE 2
For simplicity, the first pattern structure 1st and the second pattern structure 2nd are not limited to a groove structure or a protrusion structure, since the first pattern structure 1st and the second pattern structure 2nd, regardless of the groove structure or the protrusion structure, have the technical effects of suppressing the wafer quality of the 0 th order diffracted light and improving the wafer quality of the 3 rd order diffracted light (described later), and do not affect the inventive focus of the present invention, as long as the first pattern structure 1st and the second pattern structure 2nd are arranged as follows.
As shown in conjunction with fig. 3 and 4. The alignment mark unit 611 includes the 1st, 2nd, 6 th, 7 th, 12 th, 13 th, 14 th, 17 th, 18 th alignment segments 611a/611b/611f/611g/611l/611m/611n/611q/611r forming the first pattern structure 1st, and the 3 rd, 4 th, 5 th, 8 th, 9 th, 10 th, 11 th, 15 th, 16 th alignment segments 611c/611d/611e/611h/611i/611j/611k/611o/611p forming the second pattern structure 2nd, wherein the 1st to 18 th alignment segments are sequentially alignment segments arranged along the first direction. According to the alignment mark unit 611, the intensities of the 0 th, 2nd, 4 th, and 6 th order diffracted lights can be effectively suppressed from approaching 0, and thus the 1st, 3 rd, 5 th, and 7 th order diffracted lights can be used as the alignment signal, wherein the 3 rd order diffracted light is more suitable as the alignment signal since it has an intensity higher than that of the other orders diffracted light. In addition, since the wafer quality of the even-order diffracted light approaches 0, it helps to improve the contrast when alignment is performed using the odd-order diffracted light, thereby improving the accuracy of alignment.
As shown in conjunction with fig. 3 and 5. The alignment mark unit 621 includes alignment segments 621a/621b/621c/621f/621g/621l/621m/621 q/r 1st, 2nd, 3 rd, 6 th, 7 th, 12 th, 13 th, 17 th, 18 th forming the first pattern structure 1st, and alignment segments 621d/621e/621h/621i/621j/621k/621n/621o/621p 4 nd, 5 th, 8 th, 9 th, 10 th, 11 th, 14 th, 15 th, 16 th forming the second pattern structure 2nd, wherein the alignment segments 1st to 18 th are sequentially aligned segments arranged along the first direction. According to the alignment mark unit 621, the intensity of the 0 th order diffracted light can be effectively suppressed from approaching 0, and thus the 1st to 7 th order diffracted lights can be used as the alignment signal, in which the 3 rd order diffracted light is more suitable as the alignment signal since it has an intensity higher than that of the other orders diffracted light. Compared to the alignment mark unit 611, if the 3 rd order diffracted light is also used as the alignment signal, the 3 rd order diffracted light of the alignment mark unit 611 has better alignment performance, and the alignment mark unit 621 has an advantage in that it can select more orders of diffracted light as the alignment signal.
As shown in conjunction with fig. 3 and 6. The alignment mark unit 631 includes the 1st, 2nd, 4 th, 6 th, 7 th, 12 th, 13 th, 17 th, 18 th alignment segments 631a/631b/631d/631f/631g/631l/631m/631q/631r forming the first pattern structure 1st, and the 3 rd, 5 th, 8 th, 9 th, 10 th, 11 th, 14 th, 15 th, 16 th alignment segments 631 c/e/631 h/631i/631j/631k/631n/631o/631p forming the second pattern structure 2nd, wherein the 1st to 18 th alignment segments are sequentially alignment segments arranged along the first direction. According to the alignment mark unit 631, the intensity of the 0 th order diffracted light can be effectively suppressed from approaching 0, and thus the 1st to 7 th order diffracted lights can be used as an alignment signal, in which the 3 rd order diffracted light is more suitable as an alignment signal since it has an intensity higher than that of the other orders diffracted light. Compared with the alignment mark unit 611, if the 3 rd order diffracted light is also used as the alignment signal, the 3 rd order diffracted light of the alignment mark unit 611 has better alignment performance. Compared to the alignment mark unit 621, the alignment mark unit 631 has stronger intensity of the 7 th order diffracted light, and the visible alignment mark unit 631 has better alignment performance than the alignment mark unit 621 when using the 7 th order diffracted light as an alignment signal.
As shown in connection with fig. 3 and 7. In the align mark unit 641, the 1st, 2nd, 6 th, 7 th, 12 th, 13 th, 17 th, 18 th align segments 641a/641b/641f/641g/641l/641m/641q/641r forming the first pattern structure 1st and the 3 rd, 4 th, 5 th, 8 th, 9 th, 10 th, 11 th, 14 th, 15 th, 16 th align segments 641c/641d/641e/641h/641i/641j/641k/641n/641o/641p forming the second pattern structure 2nd are included, wherein the 1st to 18 th align segments are sequentially align segments arranged along the first direction. According to the alignment mark unit 641, the intensity of the 0 th order diffracted light can be effectively suppressed to approach 3, but since it is comparable to the intensities of the 1st, 2nd, 4 th, 5 th, 6 th, and 7 th order diffracted lights, and since the 3 rd order diffracted light has an intensity lower than that of the other orders diffracted light, the 3 rd order diffracted light is suitable as an alignment signal. Compared to the alignment mark unit 621 and the alignment mark unit 631, if the 3 rd order diffracted light is also used as the alignment signal, the 3 rd order diffracted light of the alignment mark unit 641 has better alignment performance.
As shown in conjunction with fig. 3 and 8. In the alignment mark unit 651, the 1st, 2nd, 3 rd, 5 th, 6 th, 10 th alignment segments 651a/651b/651c/651e/651f/651j forming the first pattern structure 1st, and the 4 th, 7 th, 8 th, 9 th, 11 th, 12 th alignment segments 651d/651g/651h/651i/651k/651l forming the second pattern structure 2nd are included, wherein the 1st to 12 th alignment segments are sequentially alignment segments arranged along the first direction. According to the alignment mark unit 651, the intensities of the 0 th, 2nd, 4 th, and 6 th order diffracted lights can be effectively suppressed from approaching 0, and thus the 1st, 3 rd, 5 th, and 7 th order diffracted lights can be used as alignment signals, in which the 3 rd order diffracted light is more suitable as an alignment signal since it has an intensity higher than that of the other orders diffracted light. In addition, since the intensity of the even-order diffracted light approaches 0, it is helpful to improve the contrast when alignment is performed using the odd-order diffracted light, thereby improving the accuracy of alignment.
As shown in conjunction with fig. 3 and 9. The align mark unit 661 includes the 1st, 2nd, 5 th, 6 th, 10 th align segments 661a/661b/661e/661f/661j forming the first pattern structure 1st, and the 3 rd, 4 th, 7 th, 8 th, 9 th, 11 th, 12 th align segments 661c/661d/661g/661h/661i/661k/661l forming the second pattern structure 2nd as the second pattern structure 2nd, wherein the 1st to 12 th align segments are sequentially align segments arranged along the first direction. According to the alignment mark unit 661, the intensity of the 0 th order diffracted light can be effectively suppressed to approach 6.9, but since it is comparable to the intensities of the 1st, 2nd, 4 th, 5 th, 6 th, and 7 th order diffracted lights, and since the 3 rd order diffracted light has an intensity lower than that of the other orders diffracted light, the 3 rd order diffracted light is suitable as an alignment signal. Compared with the alignment mark unit 651, if the 3 rd order diffracted light is also used as the alignment signal, the 3 rd order diffracted light of the alignment mark unit 661 has better alignment performance.
As shown in conjunction with fig. 3 and 10. In the alignment mark unit 671, the 1st, 2nd, 3 rd, 6 th and 10 th alignment segments 671a/671b/671c/671f/671j forming the first pattern structure 1st and the 4 th, 5 th, 7 th, 8 th, 9 th, 11 th and 12 th alignment segments 671d/671e/671g/671h/671i/671k/671l forming the second pattern structure 2nd are sequentially alignment segments arranged along the first direction. According to the alignment mark unit 671, the intensity of the 0 th order diffracted light can be effectively suppressed to approach 6.9, but since it is comparable to the intensities of the 1st, 2nd, 4 th, 5 th, 6 th, and 7 th order diffracted lights, and since the 3 rd order diffracted light has an intensity lower than that of the other orders diffracted light, the 3 rd order diffracted light is suitable as an alignment signal.
The alignment mark units 611-671 according to the first to seventh sub-embodiments all have significant improvement in the expression of the intensity of the 3 rd order diffracted light, which is increased by about 75%, 19%, 69%, 25%, 63%, 13% compared to the intensity of the 3 rd order diffracted light generated by the second standard alignment mark unit 521, and the intensity is no less than 50%. Meanwhile, the representation of the intensity of the 0 th order diffraction light is also significantly inhibited, and the intensity is not more than 10. That is, the alignment mark units 611-671 of the first sub-embodiment to the seventh sub-embodiment of the present invention can be used to perform the alignment between the photo mask and the wafer, so that the intensity of the 3 rd order diffracted light is significantly increased, and the alignment speed and accuracy between the photo mask and the wafer can be improved when the 3 rd order diffracted light is used as the alignment signal, in addition to the reduction of the contrast of the other higher order diffracted light due to the effect of the 0 th order diffracted light.
In the embodiment of the present invention, the first pattern structure 1st and the second pattern structure 2nd of the alignment segment 611a-611r/621a-621r/631a-631r/641a-641r/651a-651l/661a-661l/671a-671l extend in a second direction (e.g., Y direction in the drawing) intersecting the first direction, and the alignment mark units 611/621/631/641/651/661/671 are repeatedly arranged in the first direction to obtain a plurality of orders of diffracted light in the first direction. In one embodiment, the first direction is a transverse direction or a left-right direction (with the same direction), and the second direction is a longitudinal direction or an up-down direction (with the same direction).
Referring to fig. 11, fig. 11 is a schematic view of an alignment mark 71 according to a second embodiment of the present invention. In an embodiment, the alignment mark 71 includes at least one alignment mark unit 711, and the alignment mark unit 711 may be any one of the alignment mark units 611/621/631/641/651/661/671 of any one of the foregoing sub-embodiments, which is not described herein again. The first pattern structure 1st and the second pattern structure 2nd of the alignment segment in the alignment mark unit 711 extend in the first direction, and the alignment mark unit 711 is repeatedly laid out in the second direction to obtain the diffracted light of the plurality of orders in the second direction.
Referring to fig. 12, fig. 12 is a schematic diagram of an alignment mark 81 according to a third embodiment of the present invention. In an embodiment, the alignment mark 81 is formed by combining two identical and oppositely disposed first synthesized alignment mark 8101 and second synthesized alignment mark 8102, each synthesized alignment mark includes at least one alignment mark unit 811, and the alignment mark unit 811 may be any one of the alignment mark units 611/621/631/641/651/661/671 of any one of the foregoing sub-embodiments, which is not described herein again. The arrangement direction of the first synthetic alignment mark 8101 is complementary to the arrangement direction of the second synthetic alignment mark 8102 (for example, the first synthetic alignment mark 8101 is arranged along the direction of 45 degree angle, and the second synthetic alignment mark 8102 is arranged along the direction of 135 degree angle), and the end of each alignment segment in the alignment mark unit 811 in the first synthetic alignment mark 8101 is correspondingly connected to the end of each alignment segment in the alignment mark unit 811 in the second synthetic alignment mark 8102, so as to obtain a plurality of orders of diffracted light in the first direction and the second direction at the same time.
In summary, according to the sub-embodiments of the present invention, the intensity of the 0 th order diffraction light is no greater than 10, and the intensity of the 3 rd order diffraction light is no less than 50. Therefore, when the 3 rd order diffraction light is used as the alignment signal, the alignment speed and the alignment precision of the photomask plate and the wafer can be improved.
It is understood that the present invention can be applied to any photolithography process in semiconductor manufacturing, the present invention is not limited to the specific photolithography process, and the groove depth of the groove structure of the first pattern structure 1st or the second pattern structure 2nd can be changed according to the actual requirement (e.g. the wavelength of light used for alignment).
In summary, although the present invention has been described with reference to the preferred embodiments, the above-described preferred embodiments are not intended to limit the present invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, therefore, the scope of the present invention shall be determined by the appended claims.
Claims (16)
1. An alignment mark, comprising:
at least one alignment mark unit, each alignment mark unit comprising a plurality of alignment segments arranged along a first direction, each alignment segment being arranged as a first pattern structure or a second pattern structure, and the first pattern structure and the second pattern structure being one of a groove structure and a protrusion structure;
the plurality of alignment segments can generate a plurality of different orders of diffracted light in response to incident light, the intensity of the 0 th order diffracted light is not more than 10, and the intensity of the 3 rd order diffracted light is not less than 50.
2. The alignment mark of claim 1, wherein: the plurality of alignment segments has 18 alignment segments.
3. The alignment mark according to claim 2, wherein: each alignment segment has a width along the first direction of about 0.88 microns or about 0.97 microns.
4. The alignment mark according to claim 2, wherein: the 1st, 2nd, 6 th, 7 th, 12 th, 13 th, 14 th, 17 th, 18 th alignment segment is the first pattern structure, and the 3 rd, 4 th, 5 th, 8 th, 9 th, 10 th, 11 th, 15 th, 16 th alignment segment is the second pattern structure, wherein the 1st to 18 th alignment segments are sequentially alignment segments arranged along the first direction.
5. The alignment mark according to claim 2, wherein: the 1st, 2nd, 3 rd, 6 th, 7 th, 12 th, 13 th, 17 th, 18 th alignment segment is the first pattern structure, and the 4 th, 5 th, 8 th, 9 th, 10 th, 11 th, 14 th, 15 th, 16 th alignment segment is the second pattern structure, wherein the 1st to 18 th alignment segments are sequentially alignment segments arranged along the first direction.
6. The alignment mark according to claim 2, wherein: the 1st, 2nd, 4 th, 6 th, 7 th, 12 th, 13 th, 17 th, 18 th alignment segment is the first pattern structure, and the 3 rd, 5 th, 8 th, 9 th, 10 th, 11 th, 14 th, 15 th, 16 th alignment segment is the second pattern structure, wherein the 1st to 18 th alignment segments are sequentially alignment segments arranged along the first direction.
7. The alignment mark according to claim 2, wherein: the 1st, 2nd, 6 th, 7 th, 12 th, 13 th, 17 th and 18 th alignment segments are the first pattern structure, and the 3 rd, 4 th, 5 th, 8 th, 9 th, 10 th, 11 th, 14 th, 15 th and 16 th alignment segments are the second pattern structure, wherein the 1st to 18 th alignment segments are alignment segments arranged along the first direction in sequence.
8. The alignment mark of claim 1, wherein: the plurality of alignment segments has 12 alignment segments.
9. The alignment mark of claim 8, wherein: each alignment segment has a width along the first direction of about 1.33 microns or about 1.46 microns.
10. The alignment mark of claim 8, wherein: the 1st, 2nd, 3 rd, 5 th, 6 th and 10 th alignment segments are the first pattern structure, and the 4 th, 7 th, 8 th, 9 th, 11 th and 12 th alignment segments are the second pattern structure, wherein the 1st to 12 th alignment segments are sequentially alignment segments arranged along the first direction.
11. The alignment mark of claim 8, wherein: the 1st, 2nd, 5 th, 6 th and 10 th alignment segments are the first pattern structure, and the 3 rd, 4 th, 7 th, 8 th, 9 th, 11 th and 12 th alignment segments are the second pattern structure, wherein the 1st to 12 th alignment segments are sequentially alignment segments arranged along the first direction.
12. The alignment mark of claim 8, wherein: the 1st, 2nd, 3 rd, 6 th and 10 th alignment segments are the first pattern structure, and the 4 th, 5 th, 7 th, 8 th, 9 th, 11 th and 12 th alignment segments are the second pattern structure, wherein the 1st to 12 th alignment segments are sequentially alignment segments arranged along the first direction.
13. The alignment mark of claim 1, wherein: the first pattern structure and the second pattern structure of the alignment segment extend in a second direction intersecting the first direction, and the alignment mark units are repeatedly laid along the first direction to obtain the plurality of orders of diffracted light in the first direction.
14. The alignment mark of claim 1, wherein: the first pattern structure and the second pattern structure of the alignment segment extend in the first direction, and the alignment mark units are repeatedly arranged in a second direction intersecting the first direction to obtain the diffracted light of the plurality of orders in the second direction.
15. The alignment mark of claim 1, wherein: the alignment mark is formed by combining two identical and oppositely arranged first and second composite alignment marks, and each of the first and second composite alignment marks comprises at least one alignment mark unit so as to simultaneously obtain the diffracted lights of multiple orders in the first direction and a second direction intersecting the first direction.
16. The alignment mark of claim 15, wherein: the arrangement direction of the first composite alignment mark is complementary to the arrangement direction of the second composite alignment mark, and the tail end of each alignment segment in the alignment mark unit in the first composite alignment mark is correspondingly connected with the tail end of each alignment segment in the alignment mark unit in the second composite alignment mark.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010686298.1A CN111766765A (en) | 2020-07-16 | 2020-07-16 | Alignment mark |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010686298.1A CN111766765A (en) | 2020-07-16 | 2020-07-16 | Alignment mark |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1652021A (en) * | 2005-02-07 | 2005-08-10 | 中国科学院光电技术研究所 | Raster polarization photomask plate and its application in projection photoetching system |
| CN1902526A (en) * | 2003-09-22 | 2007-01-24 | 吉恩·多戈夫 | Omnidirectional lenticular and barrier-grid image displays and methods for making them |
| CN105549138A (en) * | 2016-03-11 | 2016-05-04 | 中国科学院微电子研究所 | Seven-grade diffraction grating structure, preparation method thereof and wafer photoetching alignment method |
| CN105607435A (en) * | 2016-03-11 | 2016-05-25 | 中国科学院微电子研究所 | Five-level diffraction grating structure and preparation method therefor, and wafer photoetching alignment method |
-
2020
- 2020-07-16 CN CN202010686298.1A patent/CN111766765A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1902526A (en) * | 2003-09-22 | 2007-01-24 | 吉恩·多戈夫 | Omnidirectional lenticular and barrier-grid image displays and methods for making them |
| CN1652021A (en) * | 2005-02-07 | 2005-08-10 | 中国科学院光电技术研究所 | Raster polarization photomask plate and its application in projection photoetching system |
| CN105549138A (en) * | 2016-03-11 | 2016-05-04 | 中国科学院微电子研究所 | Seven-grade diffraction grating structure, preparation method thereof and wafer photoetching alignment method |
| CN105607435A (en) * | 2016-03-11 | 2016-05-25 | 中国科学院微电子研究所 | Five-level diffraction grating structure and preparation method therefor, and wafer photoetching alignment method |
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