Multi-probe lithographic apparatus and lithographic method

Abstract

The invention provides a multi-probe lithographic apparatus and a lithographic method, the multi-probe lithographic apparatus comprises a plurality of exposure unit groups capable of independently moving relative to each other, and each exposure unit group comprises one or more exposure units. The photoetching method comprises the following steps: dividing a pattern to be photoetched into a plurality of sub-patterns, wherein each sub-pattern corresponds to a writing field of a single exposure unit; determining an exposure sequence of the plurality of sub-graphs, the exposure sequence indicating an exposure unit for executing exposure of each sub-graph and a moving sequence of each exposure unit, and the graph to be photoetched is simultaneously photoetched by at least the exposure units in the two exposure unit groups, the distance between any two adjacent exposure unit groups in the plurality of exposure unit groups is greater than the size of a writing field of a single exposure unit; initializing the relative position of each exposure unit group in the plurality of exposure unit groups according to the exposure sequence; and performing exposure of the image to be photoetched according to the exposure sequence.

Description

Technical Field

[0001] The present invention relates to the field of lithography technology, and more specifically, to a multi-probe lithography device and a lithography method. Background Art

[0002] Photolithography is a crucial link in chip manufacturing. Traditional photolithography uses light and photoresist to transfer the pattern on the mask to the wafer. However, with the continuous improvement of chip manufacturing process, the cost of masks has also continued to rise, and the production is complex and the cycle is long. In addition, the mask cannot be modified once it is produced. These problems have led the industry to begin researching and developing technologies that do not use photomasks, that is, maskless lithography, also known as direct write lithography.

[0003] Typical maskless lithography technologies mainly include electron beam lithography and optical (laser) direct writing lithography, depending on the exposure source. In electron beam lithography, the lithography pattern will be transferred to the photosensitive resin layer through exposure, and then the lithography pattern will be transferred to the wafer through the etching process. In recent years, scanning probe lithography (SPL) has been developed. Scanning probe lithography includes a variety of probe lithography modes, the most common of which is the lithography of the photoresist formed by the probe field emission, and the lithography formed by the probe tip heating to burn the photoresist. Due to its nanometer-level precision and nanometer-level line width, probe lithography has become a single-nanometer-level lithography technology.

[0004] The biggest problem currently faced by scanning probe lithography technology is the slow lithography speed, because its lithography process is a point-by-point exposure process. The speed of probe scanning depends not only on the scanning speed of the probe scanner, but also on factors such as the current density of the probe. For thin films, the dose of the electron beam is sufficient for short-time exposure, and the lithography speed depends on the scanning speed. For thick films, a long exposure is required at one point to obtain a sufficient number of charges, so the lithography speed depends on the electron beam current. Under the constraints of the existing probe scanner scanning speed and the current density of the probe tip, one of the effective ways to increase the probe lithography speed is to develop multi-probe technology, using multiple probes for simultaneous lithography, and the lithography speed will increase linearly with the number of probes. As a result, parallel probe arrays came into being.

[0005] In the probe array, the distance between adjacent probes can be smaller than the write field range of a single probe, generally between 10 microns and 100 microns. Therefore, the write fields between parallel probes must overlap so that seamless stitching of graphics can be formed between the write fields. The probe itself can also perform microstructure measurements, and the measurement range of the probe can be larger than the write field range, that is, the boundary of the write field can be "seen" by the probe, thereby controlling each probe to emit or not emit electrons at the overlap of the write field. This is the premise for non-repetitive exposure of two adjacent write fields at the overlap of adjacent write fields during lithography.

[0006] However, in many cases, even if a parallel probe array is composed of multiple probes with a pitch smaller than the writing field of a single probe, it is still impossible to create enough probes for simultaneous lithography due to the limited number of probes in the probe array and the difficulty of making a tightly packed probe array. In addition, there are many application scenarios where the lithography pattern is huge, far larger than the writing field range formed by a single probe or parallel probe array.

[0007] Therefore, it is desirable to provide improved apparatus and methods to further increase the lithography speed of scanning probe lithography. Summary of the invention

[0008] This Summary is provided to introduce some concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0009] The present invention provides an improved multi-probe scanning lithography device, in which the probes are divided into a plurality of exposure unit groups capable of performing exposure simultaneously, and each exposure unit group includes one or more exposure units. Adjacent exposure unit groups can be spaced relatively large apart, thereby meeting the speed requirements for simultaneous large-size graphic lithography. At the same time, the present invention provides a method for eliminating the splicing errors between different exposure unit groups, thereby improving the splicing accuracy between various graphics in large-size graphic lithography. The splicing error elimination method between exposure unit groups of the present invention is applicable to various exposure unit group arrangements, so that the present invention can flexibly set the position and exposure order of the exposure unit group according to the actual situation of the graphic to be photolithography, further improving the lithography efficiency and reducing the manufacturing cost.

[0010] According to one aspect of the present invention, there is provided a lithography method for a multi-probe lithography device, the multi-probe lithography device comprising a plurality of exposure unit groups that can be moved independently relative to each other, each exposure unit group comprising one or more exposure units, the method comprising: dividing a pattern to be photolithographically processed into a plurality of sub-patterns, each sub-pattern corresponding to a writing field of a single exposure unit; determining an exposure sequence of the plurality of sub-patterns, wherein the exposure sequence indicates an exposure unit that performs exposure of each sub-pattern and a movement sequence of each exposure unit, wherein the pattern to be photolithographically processed is simultaneously photolithographically processed by exposure units in at least two exposure unit groups, and a distance between any two adjacent exposure unit groups in the plurality of exposure unit groups is greater than a size of a writing field of a single exposure unit; initializing a relative position of each exposure unit group in the plurality of exposure unit groups according to the exposure sequence; and performing exposure of the image to be photolithographic processed according to the exposure sequence.

[0011] According to a further embodiment of the present invention, initializing the relative position of each exposure unit group in a plurality of exposure unit groups according to an exposure sequence further includes: moving each exposure unit group to a corresponding initial exposure position according to the exposure sequence; determining an intra-group write field stitching error of each exposure unit group and an inter-group write field stitching error with adjacent exposure unit groups; and adjusting the position of each exposure unit group to compensate for the determined intra-group write field stitching error and inter-group write field stitching error.

[0012] According to a further embodiment of the present invention, determining the intra-group write field stitching error of each exposure unit group and the inter-group write field stitching error between adjacent exposure unit groups further includes: for each exposure unit in the exposure unit group: exposing a first write field mark indicating a current write field range; observing whether there is a second write field mark exposed by other exposure units in the observation range of the exposure unit; in the case where the second write field mark exists, determining the second write field range corresponding to the second write field mark; determining whether the second write field mark is exposed by an exposure unit in the same exposure unit group or by an exposure unit in a different exposure unit group; if the second write field mark is exposed by an exposure unit in the same exposure unit group, measuring the write field stitching error based on the current write field range and the second write field range, and recording it as an intra-group write field stitching error, moving to the next write field according to the exposure order, and repeating the above steps; and if the second write field mark is exposed by an exposure unit in a different exposure unit group, measuring the write field stitching error based on the current write field range and the second write field range, and recording it as an inter-group write field stitching error.

[0013] According to a further embodiment of the present invention, adjusting the position of each exposure unit group to compensate for the determined intra-group write field stitching error and inter-group write field stitching error further includes: adjusting the position of each exposure unit in each exposure unit group to compensate for the intra-group write field stitching error and inter-group write field stitching error according to the intra-group write field stitching error and inter-group write field stitching error recorded by the exposure units of each exposure unit group.

[0014] According to a further embodiment of the present invention, a plurality of exposure unit groups are configured to move in two moving dimensions orthogonal to each other on a working plane parallel to the wafer, and each exposure unit in the exposure unit group is configured to be able to perform scanning exposure in two scanning dimensions orthogonal to each other on the working plane parallel to the wafer, and the two scanning dimensions are respectively parallel to the two moving dimensions.

[0015] According to a further embodiment of the present invention, the two movement dimensions are the horizontal axis and the vertical axis in a Cartesian coordinate system.

[0016] According to a further embodiment of the invention, the two movement dimensions are radial and tangential to the circle.

[0017] According to a further embodiment of the present invention, each exposure unit group moving to the corresponding initial exposure position further includes: selecting an exposure unit group among multiple exposure unit groups whose initial exposure positions are on the same circumference as a reference exposure unit group; exposing an exposure unit in the reference exposure unit group along a tangential direction to a reference circular line; adjusting the positions of the remaining exposure unit groups in the multiple exposure unit groups to the reference circular line based on the reference circular line; and moving each exposure unit group along the reference circular line to the corresponding initial exposure position.

[0018] According to a further embodiment of the present invention, initializing the relative position of each exposure unit group in the plurality of exposure unit groups according to the exposure sequence further comprises: calibrating each exposure unit scanner so that its two scanning dimensions are parallel to the radial direction and the tangential direction of the circle respectively.

[0019] According to a further embodiment of the present invention, calibration is performed on each exposure unit so that its two scanning dimensions are respectively parallel to the radial direction and the tangential direction of the circle, further comprising: the exposure unit to be calibrated exposes a mark on the reference circumferential line as a reference point; moves a predetermined distance toward the center of the circle along a first scanning dimension of the two scanning dimensions that is expected to be parallel to the radial direction of the circle; exposes a straight line along a second scanning dimension of the two scanning dimensions that is expected to be parallel to the tangential direction of the circle, so that the straight line intersects the circumferential line at a first point and a second point; measures the length of a first arc between the first point and the reference point and a second arc between the second point and the reference point; the exposure unit to be calibrated returns to the reference point and rotates a certain angle along the axis of the exposure unit to be calibrated itself according to the comparison result of the lengths of the first arc and the second arc; and repeats the above steps until the lengths of the first arc and the second arc are equal.

[0020] According to another invention of the present invention, a multi-probe lithography device is provided, including: a wafer workbench for carrying a wafer to be lithographed; an exposure system, the exposure system including a plurality of exposure unit groups, each exposure unit group including one or more exposure units; and a control unit, the control unit being used to control the exposure system to execute a lithography method as the present invention to expose the wafer carried on the wafer workbench.

[0021] According to a further embodiment of the present invention, the exposure unit uses any one of the following types as exposure source: electron beam emitted via high voltage field; electron beam emitted via filament heating; electron beam emitted via probe field; thermal radiation via probe tip heating; or laser beam.

[0022] According to a further embodiment of the present invention, a plurality of exposure unit groups are arranged in any one of the following arrangements on a plane parallel to the wafer worktable: orthogonal arrangement in a Cartesian coordinate system; orthogonal arrangement in a Cartesian coordinate system with a staggered orientation; parallel arrangement in a Cartesian coordinate system at an angle; radial arrangement along coaxial circles in a radial coordinate system; or radial arrangement along the same circle in a radial coordinate system.

[0023] These and other features and advantages will become apparent by reading the following detailed description and by reference to the associated drawings.It is to be understood that the foregoing general description and the following detailed description are illustrative only and are not restrictive of the aspects of what is claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to understand the manner in which the above features of the present invention are used in detail, the above briefly summarized contents can be described in more detail with reference to various embodiments, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings only show some typical aspects of the present invention and should not be considered to limit its scope, because the description may allow for other equally effective aspects.

[0025] Figure 1 It is a schematic structural diagram of a scanning lithography device in the prior art.

[0026] Figure 2 is a schematic diagram of a lithography apparatus according to a first embodiment of the present invention.

[0027] Figure 3 is a schematic diagram showing write field splicing according to the first embodiment of the present invention.

[0028] Figure 4 is a schematic diagram showing write field splicing according to the second embodiment of the present invention.

[0029] Figure 5 is a schematic diagram showing the arrangement of probe groups according to the third embodiment of the present invention.

[0030] Figure 6 FIG. 4 is a schematic diagram showing another probe group arrangement according to the third embodiment of the present invention.

[0031] Figure 7 FIG. 4 is a schematic diagram showing another probe group arrangement according to the third embodiment of the present invention.

[0032] Figure 8 is a schematic diagram showing write field splicing according to a fourth embodiment of the present invention.

[0033] Fig. 9 FIG. 4 is a schematic diagram showing the arrangement of probe groups according to the fourth embodiment of the present invention.

[0034] Fig.10is a schematic diagram showing the calibration of the probe scanning dimension according to the fourth embodiment of the present invention.

[0035] Fig.11 is a schematic flow chart illustrating a photolithography method according to various embodiments of the present invention.

[0036] Fig.12 It is shown Fig.11 Schematic diagram of pattern division and exposure sequence in the lithography method. DETAILED DESCRIPTION

[0037] Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided for a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0038] In the description of the present invention, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc. indicate positions or positional relationships only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0039] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of the present invention. In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0040] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0041] In the description of the embodiments of the present invention, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0042] Figure 1 It is a schematic structural diagram of a scanning lithography device in the prior art. The lithography device includes: a wafer worktable 100, which is used to carry a wafer 110 to be processed. The lithography machine is a step-by-step lithography machine, which can achieve the purpose of sequentially exposing different regions of the wafer by gradually moving the wafer worktable. A probe sensor device 90 is arranged above the wafer worktable, and the probe sensor device includes two probe sensor heads 91 and 92. The probe sensor head is located above the photosensitive layer, and moves and scans in a certain scanning area and determines the coordinates of the positioning mark in the area.

[0043] An exposure beam generator 300 is arranged above the wafer, and is used to provide the exposure beam required for exposing the wafer area, and the exposure beam forms a projection exposure area on the wafer. In addition, the lithography equipment also includes a displacement drive device 400, which is used to adjust the relative position of the exposure beam generator and the wafer worktable according to the positioning mark coordinates measured by the nano-needle tip sensor device, so that the projection exposure area is aligned with the wafer area to be exposed.

[0044] Figure 1 The photolithography apparatus shown also includes a computer control system 200, which is used to receive the positioning mark coordinates measured by the probe sensor device 90 and compare the positioning mark coordinates with the reference coordinates to obtain the displacement difference between the two coordinates in the horizontal or vertical direction. The computer control system transmits the displacement difference to the displacement drive device 400, and the displacement drive device 400 causes the exposure beam generating device and / or the wafer worktable to move accordingly to reduce the error between the two exposures of the same wafer area.

[0045] As mentioned in the background technology section, Figure 1The lithography equipment also has the problem of slow speed during lithography, especially when large-sized lithography patterns need to be exposed. In order to speed up the lithography speed, it is easy to think of using multiple sets of such exposure beam generating devices and probe sensing devices to work simultaneously. However, when multiple sets are used, the problem that follows is a more complicated alignment problem, because the error between different sets may be much greater than the internal error when there is only one set.

[0046] In order to overcome this problem, the present invention provides an improved multi-probe scanning lithography apparatus. Figure 2 FIG. 2 shows a schematic structural diagram of a scanning probe lithography apparatus according to an embodiment of the present invention. Figure 2 As shown in , a scanning probe lithography apparatus (hereinafter referred to as "lithography apparatus") includes a wafer table for carrying a wafer to be lithographically processed, and an exposure system for exposing the wafer carried on the wafer table. In various embodiments of the present invention, the exposure system includes a plurality of exposure units that can simultaneously perform exposure in their respective writing fields. In order to speed up the lithography speed, the plurality of exposure units of the lithography apparatus of the present invention can be divided into a plurality of exposure unit groups, each of which can include one or more exposure units. Each exposure unit includes an exposure source and a corresponding probe scanner, and the probe scanner carries a probe for determining the relative position of the exposure source and the wafer. The exposure source may include, but is not limited to: an electron beam emitted via a high voltage field as an exposure source, an electron beam emitted via filament heating as an exposure source, an electron beam emitted via a probe field as an exposure source, thermal radiation heated via a probe needle tip as an exposure source, or other types of exposure sources. The probe scanner may be fixed on one or more beams, and the movement of the beam can drive the overall long-distance movement of the probe scanner fixed thereon, for example, the overall movement to the next row or column of the writing field area or a farther position. Each probe scanner can be finely moved in multiple dimensions within its writing field to control point-by-point scanning lithography within the writing field.

[0047] The sample with photoresist coated on the surface is fixed on the wafer workbench. The wafer workbench can be similarly moved and / or rotated in multiple dimensions, and the beam that fixes the multi-probe group can also be moved and / or rotated in multiple dimensions. The scanning exposure of each probe's respective writing field is completed by scanning by the scanner connected to each probe. The movement of the wafer workbench or the beam is used to realize the removal of each probe's respective writing field, so that each probe can move to the next adjacent internal writing field to perform exposure.

[0048] In order to facilitate understanding of the present invention, the following description is made by taking the scanning probe lithography apparatus as an example, in which a probe sends an electron beam to perform lithography. In addition, for the convenience of description, the "exposure unit" that performs positioning and exposure based on the probe scanner, especially the probe therein, is represented and indicated by the "probe", and accordingly, the "probe group" is used to represent its corresponding "exposure unit group".

[0049] In the existing multi-probe scanning scheme, adjacent probes are close to each other, that is, the spacing between them is slightly smaller than the size of a lithography writing field, so that adjacent writing fields can partially overlap to achieve "seamless splicing" of the writing field. However, when the pattern to be photolithographic is a "large-size pattern" that is much larger than the size of a single lithography writing field, even if multiple probes are lithographed simultaneously, it still takes a long time. For this reason, unlike the existing multi-probe scanning scheme, in various embodiments of the present invention, the lithography equipment of the present invention may include multiple probe groups, and the spacing between adjacent probe groups is larger than the size of a single lithography writing field that can be achieved by a single probe, for example, at least twice the size of a single lithography writing field. Each probe group may include one or more probes, and the probes in the probe group may be close to each other like the existing multi-probes. Multiple probe groups can be distributed at different initial positions according to the different patterns to be photolithographic, and multiple probes in the probe group may also have different distribution positions. It should be noted that although the initial positions of the probe groups and probes are known, the specific precise position of each probe still needs to be determined, especially each probe group and probe may introduce errors after the position is moved during the lithography process. Therefore, it is necessary to perform calibration of all probe positions before the formal lithography begins so that their corresponding write fields can be seamlessly spliced ​​and finally spliced ​​into the required "large-size graphics". The following will describe in detail the process of determining the write field splicing error between probe groups in various implementations in which the probe groups and probes adopt different distributions. For ease of description, in the following implementations, each probe has the same rectangular write field, the width of the write field in the X-axis direction is w, and the height in the Y-axis direction is h.

[0050] Figure 2 The schematic diagram of the structure of FIG. 1 shows a scenario corresponding to the first embodiment of the present invention, wherein the lithography device includes two probe groups, each probe group includes one probe. Figure 1 As shown in , the lithography equipment has two probe groups, each probe group has a probe, named probe 1 and probe 2, respectively. Probe 1 and probe 2 are placed on their own multi-dimensional scanners, for example, the scanner can move three-dimensionally in mutually perpendicular XYZ axes, or can also rotate in the working horizontal plane. The scanner is generally piezoelectric driven, with laser grating calibration to form a closed-loop control of the scanner displacement, with extremely high nanometer or even picometer positioning accuracy.

[0051] In order to determine the error between the writing fields of the two probe groups, it is first necessary to move the two probe groups to the same moving dimension. For the convenience of movement and control, the workbench, the beam, and the scanner can be configured to move in multiple dimensions with the same dimension, for example, all move in an XYZ Cartesian coordinate system, wherein XY can represent the horizontal axis and the vertical axis in the horizontal working plane, and Z represents the height direction perpendicular to the horizontal plane. After the writing field splicing of the horizontal plane is completed, the splicing on the height between the writing fields can be completed by separately controlling and calibrating the height of each probe. Therefore, for the convenience of description, only the writing field splicing and error elimination on the horizontal working plane are considered in each embodiment of the present invention. Therefore, in this step, the two probe groups are first moved to the same moving dimension, that is, the same position on the X-axis or the same position on the Y-axis, which depends on the direction of the writing field of the probe moving out. For example, when the probe moves out to the next writing field along the horizontal direction after completing the current writing field, the moving dimension is the X-axis, then the two probes are also moved to the X-axis in advance, that is, the same height on the Y-axis.

[0052] In this embodiment, the two probes are fixed on a common beam, and it is set that the probes will move out in a direction parallel to the beam after the current write field is completed, so they can be regarded as being in the same moving dimension. However, it should be understood that the two scanners do not necessarily have to be fixed on the same beam, but can also be fixed on two different beams. In this case, the probes can be moved to the same moving dimension by moving the beam. In addition, as mentioned earlier, in order to achieve lithography and splicing of large-size graphics, the movement range of the wafer workbench and the probe group beam is at least twice the range of a single write field scanned by the probe, that is, the wafer workbench or the probe group beam is responsible for moving the write field out so as to leave a write field range for the probe group to expose adjacent write fields.

[0053] Subsequently, the two probe groups expose write field marks one by one in the same direction along the dimension, and observe whether there are write field marks exposed by other exposure units according to the write field marks, and measure whether the current write field overlaps with the write field exposed by the adjacent probe group according to the write field marks. In order to achieve seamless splicing of the write fields, the write field range of each probe is generally set to be smaller than its observation range, so that the probe can "see" at least a part of the adjacent write field.

[0054] Writing the entire write field in order to find the stitching errors between the probes takes a huge amount of time. Therefore, it is efficient to expose a quick and simple mark pattern in each write field and at the intersection with the next adjacent write field so as to quickly determine the current position of each write field, especially the relative position with the adjacent write field. For ease of description, in the following initialization stage involving determining and eliminating the stitching errors of the write field, the reference to "exposure of the write field" refers to "exposure of the write field mark indicating the range of the write field", rather than exposing the pattern to be lithographed in the write field during formal lithography.

[0055] More specifically, if Figure 2 As shown in , it is assumed that initially at time A: probe 1 is at position 11, ready to start exposure of write field 11, and probe 2 is at position 21, ready to start exposure of write field 21.

[0056] Next, at time B: probes 1 and 2 have completed the exposure of write field 11 and write field 21 respectively, and move to positions 12 and 22 respectively through the movement of the wafer worktable or the beam, preparing to start the exposure of write field 12 and write field 22.

[0057] Subsequently, at time C: probes 1 and 2 complete the exposure of write field 12 and write field 22 respectively. At this time, the probes can observe whether there are write field marks exposed by other exposure units in their respective observation ranges. If so, it is further determined whether they are exposed by the same group of probes. The mark of the current write field and the mark of the previous write field can measure the stitching error between the current write field and the previous adjacent write field. The method for measuring the stitching error can adopt any measurement method used in the existing write field stitching technology, for example, by using the atomic force microscopy function of each probe itself to measure the characteristics of the exposed write field mark, such as the latent image, and then by comparing the positions of the two write fields, the stitching error between the two can be obtained.

[0058] The write field identifiers of different probe groups can adopt different marking forms, so that the probe groups can distinguish which are the write field marks exposed by themselves or the same probe group, and which are the write field marks exposed by the probes of other probe groups. Therefore, probes 1 and 2 can further determine whether the current write field overlaps with the write fields of other probe groups. In this example, probes 1 and 2 use the write field marks to distinguish that the previous write field, that is, write field 11 and write field 21, are both exposed by probes 1 and 2 themselves, so each measures and records the inter-group stitching error between the current write field and the previous write field. In this article, the stitching error between adjacent write fields exposed by each probe itself is called the intra-group write field stitching error, denoted as ΔXa ij, where a stands for intra, which means internal stitching, i stands for the probe identifier, j stands for the number of writing fields exposed by the probe, and ij stands for the current writing field. For example, at this time, probe 1 has exposed the writing field marks of writing fields 11 and 12. Since the first writing field 11 itself has no stitching error, the stitching error starts from the second writing field 12. Therefore, the stitching error between the current writing field and the previous writing field can be represented by the identifier of the current writing field. Therefore, in this example, the stitching error between the writing field 11 and the writing field 12 exposed by probe 1 itself can be expressed as ΔXa 12 , represents the splicing error between the current writing field 12 and the previous writing field 11. Similarly, ΔXa 22 This may indicate a stitching error between the current write field 22 of probe 2 and the previous write field 21. Therefore, the method continues, and probes 1 and 2 are moved to positions 13 and 23, respectively, by moving the wafer stage or beam, to prepare to start exposure of write field 13 and write field 23. Since no write field marks of other probe groups are found, the method continues.

[0059] Subsequently, at time D:, probes 1 and 2 complete the exposure of write field 13 and write field 23, respectively. Similarly, by observing the mark of the current write field and the mark of the previous write field, the splicing error between the current write field and the previous adjacent write field can be measured. Figure 2 As shown in , at this time, write field 23 overlaps with write field 11. From the perspective of probe 2, through observation, both the mark of write field 22 and the mark of write field 11 can be found, and further through the write field mark, it can be determined that the mark of write field 22 is left by probe 2 itself, while the mark of write field 11 is not the mark of probe 2 itself. Therefore, probe 2 can determine that write field 23 overlaps with the write field of another probe group. At this time, probe 1 observes and records the internal stitching error ΔXa between write field 13 and write field 12 13 , and probe 2 observes and records the internal stitching error ΔXa between writing field 23 and writing field 22 23 , and also observe and record the external stitching error between writing field 23 and writing field 11. This external stitching error is called the inter-group writing field stitching error, denoted by ΔXr mn , where r represents inter, i.e., the external stitching between adjacent probe groups, m and n represent probe groups, for example, the external stitching error between write field 23 and write field 11 here actually represents the stitching error between probe group 1 and probe group 2, so it is recorded as ΔXr 12 .

[0060] Thus, the errors between each writing field between probe 1 and probe 2 have been observed and determined. After knowing these errors, they can be eliminated by compensation in the subsequent formal lithography. ijThe error is usually very small, and ΔXr mn The error can be very large, which is determined by the spacing between the probe groups. Generally, the larger the spacing between the probe groups, the larger the ΔXr mn Therefore, when comparing these two errors, in some cases, ΔXa ij can even be ignored, but ΔXr mn The errors must be eliminated before large-size photolithography patterns can be spliced ​​together.

[0061] It should be understood that Figure 2 The schematic diagram and the above description of the first embodiment only mention the error elimination in the X-axis direction, however Figure 2 The process can not only eliminate the error of the two probe groups in the X-axis direction, but also detect the error of the two probe groups in the Y-axis direction through the above process. In fact, when marking the writing field, if the single writing field is rectangular, the rectangular perimeter of the writing field can be indicated by marking. For example, Figure 3 The corresponding Figure 2 As shown in the schematic diagram of writing field stitching, cross marks can be exposed at the four vertices of the rectangle, or at any three of the vertices, or at least at the two diagonal vertices, to indicate the range of the writing field. Therefore, when observing whether the ranges of two adjacent writing fields overlap and the stitching error between the two, ΔXa can be obtained at the same time. ij and ΔYa ij and ΔXr mn and ΔYr mn The writing field mark may also be in other forms, and may be large enough to cover the entire writing field, such as directly exposing the entire perimeter of a rectangular writing field as a mark.

[0062] Figure 4 FIG. 1 shows a schematic diagram of a write field splicing according to a second embodiment of the present invention, wherein the lithography apparatus comprises a plurality of probe groups, each probe group comprising a probe. As a non-limiting example, in Figure 4 In the example of , the lithography apparatus may include four probe groups, each probe group including one probe. Similar to the first embodiment, the four probe groups may still be fixed on one beam, or may be fixed on different beams. If they are fixed on different beams, they are all pre-moved to the same moving dimension by moving the beams. Subsequently, the writing field splicing error determination process as performed in the first embodiment may be performed. Figure 4 As shown in FIG, after the mark exposure process of three writing fields, the internal stitching error ΔXa of the probe group can be finally obtained. 12 , ΔXa 13 , ΔXa 22 , ΔXa 23 , ΔXa 32, ΔXa 33 , ΔXa 42 and ΔXa 43 , and the probe set external splicing error ΔXr 12 , ΔXr 23 and ΔXr 34 Similarly, the internal splicing ΔYa of the probe group in the Y direction can also be obtained 12 , ΔYa 13 , ΔYa 22 , ΔYa 23 , ΔYa 32 , ΔYa 33 , ΔYa 42 and ΔYa 43 , and the probe set external splicing error ΔYr 12 , ΔYr 23 and ΔYr 34 (not shown in the figure). In addition, it should be understood that Figure 4 In the example, the four probe groups are roughly moved to be roughly evenly distributed in the X-axis direction during initialization, so after the same batch of write field exposure, probes 2, 3, and 4 all simultaneously find the write field overlap between probe groups. However, the multiple probe groups can also be distributed unevenly in the same moving dimension as needed, which may cause the write field overlap to occur after different batches of write field exposure. For example, if probe groups 2 and 3 are closer than probe groups 3 and 4, when probe 3 finds the write field mark left by probe 2, probe 4 has not yet found the write field mark left by probe 3. At this time, probes 3 and 4 can still move to the next write field position together with probes 1 and 2, but in the next write field mark exposure cycle, probe 3 no longer performs exposure, while probe 4 continues to perform exposure until it finds the write field overlap with probe 3. In this process, it is only necessary to record the internal errors and external errors of each probe group, and each error can still be eliminated by compensation during the subsequent formal exposure.

[0063] Figure 5 FIG. 1 shows a schematic diagram of a write field splicing according to a third embodiment of the present invention, wherein the lithography apparatus includes a plurality of probe groups, each of which includes one probe. Different from the first and second embodiments, in the third embodiment, the plurality of probe groups are no longer arranged in one dimension by movement, but are arranged in Cartesian coordinates. As a non-limiting example, in Figure 5In the example of , a total of 4 probe groups are shown, each probe group includes a probe, and after the initialization movement, the 4 probe groups are arranged orthogonally in a 2x2 pattern. More specifically, probes 1 and 2 are arranged on the X-axis similarly to the arrangement in the first embodiment, and the spacing between them is greater than twice the width w of the rectangular writing field, while probes 3 and 4 are arranged in the second row, respectively below probes 1 and 2, and the spacing between them is approximately equal to the spacing between probes 1 and 2, and the spacing between these two rows of probes (i.e., probes 1 and probes 3 and probes 2 and probes 4) on the Y-axis is greater than twice the height h of the rectangular writing field. Subsequently, the error determination process can be performed on the X-axis and the Y-axis in sequence. For example, probes 1 and 2 and probes 3 and 4 can synchronously perform the error determination process on the X-axis first, as in the process performed in the first embodiment, thereby determining and recording the errors between probes 1 and 2 and between probes 3 and 4 on the X-axis. Subsequently, starting from the current position, probes 1 and 2 and probes 3 and 4 can synchronously perform a similar error determination process on the Y-axis again. In other words, multiple probe groups arranged in Cartesian coordinates can perform a single-dimensional error determination process in two dimensions of the Cartesian coordinates respectively, and finally record these errors for compensation in the formal exposure process.

[0064] It should be understood that the Cartesian coordinate arrangement does not necessarily require that the probe groups be distributed completely regularly. Figure 6 As shown, multiple probe groups can also be arranged in a staggered orthogonal manner. Figure 7 In the diagram of FIG, it is shown that multiple probe groups can be arranged in parallel at an angle. These arrangements are similar to Figure 5 The error determination process of the orthogonal arrangement in is basically similar, and the single-dimensional error determination process is still performed in two dimensions of the Cartesian coordinates one after another. In addition, it can be further imagined that, in theory, even if multiple probe groups are arranged completely irregularly on the X-axis and the Y-axis, it is only necessary to perform the single-dimensional error determination process in two dimensions of the Cartesian coordinates one after another, so that each probe group continuously performs write field mark exposure in each dimension until it overlaps with the write field of other probe groups. As long as all the write fields on the entire wafer are exposed, it can be ensured that the wafer pattern can be exposed through write field splicing, and the errors between the write fields can still be determined and eliminated.

[0065] Figure 8 A schematic diagram of writing field splicing according to a fourth embodiment of the present invention is shown, wherein the lithography apparatus comprises two probe groups, each probe group comprises a plurality of probes, and the two probe groups and each of the probes therein are arranged in one dimension. As a non-limiting example, in Figure 8In the example, the lithography equipment may include two probe groups, probe group 1 and probe group 2, each probe group includes two probes, wherein probe group 1 includes probe 11 and probe 12, and probe group 2 includes probe 21 and probe 22. The spacing between the probe groups still needs to be greater than twice the size of a single write field. It should be noted that the spacing between the probe groups here refers to the two probes closest to the adjacent probe group in the two probe groups, rather than the two probes in the corresponding arrangement positions. In this example, the two probes closest to the other probe group in probe group 1 and probe group 2 are probe 11 and probe 22, so the spacing between probe 11 and probe 22 needs to be greater than twice the width w of the rectangular write field, rather than the spacing between probe 11 and probe 21 or probe 12 and probe 22 satisfying the requirement of being greater than twice the width w of the rectangular write field.

[0066] In this scenario, similar to the stitching error determination process in the first embodiment, probes 11, 12, 21, and 22 are first moved to the same moving dimension, for example, to the same X-axis direction. Then, the four probes all perform the first write field mark exposure process, and the write fields exposed by probes 11, 12, 21, and 22 are write field 111, write field 121, write field 211, and write field 221, respectively.

[0067] Then, the probe group internal error ΔXa between the writing field 121 and the writing field 111 is observed and recorded. 121 and the probe group internal error ΔXa between the writing field 221 and the writing field 211 221 .

[0068] Next, the probe group is moved laterally, and probes 11 , 12 , 21 , and 22 are moved to the next writing field position, ie, writing field 112 , writing field 122 , writing field 212 , and writing field 222 , respectively, and corresponding writing field marks are exposed.

[0069] Then, the probe group internal error ΔXa between the writing field 122 and the writing field 112 is observed and recorded. 122 and the probe group internal error ΔXa between the writing field 222 and the writing field 212 222 At the same time, the probe group internal error ΔXa between the writing field 112 and the writing field 121 is also observed and recorded. 112 and the probe group internal error ΔXa between the writing field 212 and the writing field 221 212 .

[0070] Since the probe writing fields of different probe groups have not overlapped so far, the process continues. The probe group is moved laterally, and probes 11, 12, 21, and 22 are moved to the next writing field positions, namely, writing field 113, writing field 123, writing field 213, and writing field 223, respectively, and the corresponding writing field marks are exposed.

[0071] At this time, the probe group internal error ΔXa between the writing field 123 and the writing field 113 123 and the probe group internal error ΔXa between the writing field 223 and the writing field 213 223 At the same time, it is found that the writing field 223 overlaps with the writing field 111. At this time, the probe group external error between the writing field 223 and the writing field 213 is observed and recorded, that is, the splicing error ΔXr between the probe group 1 and the probe group 2 12 .

[0072] Similar to the previous implementation, all internal errors and external errors of the probe group are recorded so as to eliminate the errors through compensation during the subsequent formal exposure.

[0073] It can be understood that, similar to the changes of the fourth embodiment relative to the first embodiment, each embodiment in which the probe group includes only one probe can be expanded to a situation in which each probe group includes multiple probes. In order to avoid redundancy, they will not be described one by one here.

[0074] In the first to fourth embodiments described above, the probe, the probe group and the workbench all use the two coordinate axes of the Cartesian coordinate system as two movement dimensions, namely, lateral and longitudinal movement. However, additionally or alternatively, the lithography apparatus may also be configured to move the probe and the workbench in other movement dimensions, such as rotation around the center of a circle and radial translation. Fig. 9 The schematic diagram of the arrangement of the probe lithography array according to the fifth embodiment of the present invention is shown, wherein the probes are arranged to be distributed around the rotation center (for example, the center of the wafer), and each probe can perform scanning in the tangential direction and radial direction of the circle. It can be understood that Fig. 9 The eight probes shown in the figure are merely examples, and these eight probes may represent either a single probe or a probe group consisting of a plurality of probes placed close to each other, with the spacing between adjacent probe groups being greater than twice the size of the write field of a single probe (here, the tangential width of the write field).

[0075] For this type of lithography equipment, there is also a need for writing field splicing. It can be imagined that the writing field of each probe is a section of a circular ring, and the writing fields of multiple probes distributed at the same radial position can be spliced ​​into a complete circular ring. Therefore, the writing field splicing and splicing error determination methods described in the first to fourth embodiments are also applicable to this type of lithography equipment, and it is only necessary to replace the horizontal and vertical Cartesian coordinate system movement dimensions with the radial and tangential movement dimensions of the circle.

[0076] As mentioned in the first to fourth embodiments, in the process of determining and eliminating stitching errors, it is first necessary to move multiple probe groups to the same dimension, that is, the same position in the radial direction of the circle, which can be understood as all probes being located on a coaxial circumference. Unlike the movement in the Cartesian coordinate system, it is difficult to accurately control the movement of each probe to a coaxial circumference. To this end, the present invention further provides a method for calibrating each probe to a coaxial circumference. Specifically, one of the multiple probes is first selected as a reference, and the probe is moved to the desired radial position, and then the probe is rotated along the tangential axis and a complete circular line is exposed. Then, the remaining probes can measure the circular line, and adjust the position as a reference, move to the same circumference, and finally move to a suitable position on the circular line according to the setting of the probe group.

[0077] Another thing that needs to be calibrated is that the scanning dimensions of each probe itself are adapted to the radial and tangential directions of the circle. The scanning dimensions of each probe scanner are still in Cartesian coordinates, that is, they move and scan along their respective XY coordinates. Therefore, it is necessary to ensure that the scanning dimensions of each probe are aligned with the moving dimensions of the wafer table or the probe, for example, the X-axis of the lateral movement of the probe is aligned with the tangential direction of the circle, and the Y-axis of the longitudinal movement is aligned with the radial direction of the circle. To this end, the present invention further provides a method for calibrating the tangential movement axis of the probe with the tangential direction of the circumference. Fig.10 is a schematic diagram illustrating this calibration process. Fig.10 As shown in , the dotted lines show the radial R and tangential T of the circle, and the probe 1 is located at a point O on the circle. The moving axes of the probe 1 itself are the X-axis and the Y-axis, where the X-axis is expected to be aligned with the tangential T of the circle, and the Y-axis is expected to be aligned with the radial R of the circle. At the beginning of the calibration, the probe 1 first exposes a mark at point O as a reference. Then it moves a certain distance d along the Y-axis toward the center of the circle, and then exposes a straight line along the X-axis so that the straight line intersects the circle at points A and B. The distance d can be arbitrary, but the moving range of the probe in the X-axis needs to be considered to ensure that the exposed straight line can intersect the circle. Subsequently, the probe measures the lengths of the arcs AO and BO at both ends through its own measurement function. In Fig.10In the example, in order to more clearly reflect the calibration process, the situation where the Y axis is not fully aligned with the radial direction R is shown. Therefore, the length of AO is slightly shorter than the length of BO. According to this measurement result, it can be determined that the Y axis of the current probe is not fully aligned with the radial direction R, and is offset clockwise relative to the radial direction R. Therefore, after the probe is controlled to return to point O, it is slightly rotated counterclockwise along its own axis, and then the process is performed more than once until the arc lengths on both sides are equal. When the arc lengths on both sides are equal, it means that the Y axis is fully aligned with the radial direction R, and accordingly, the X axis is naturally aligned with the tangent direction T of the circumference. This calibration process can be performed on all probes before the write field stitching error determination process to ensure that the determined write field stitching error is accurate.

[0078] The above embodiments describe the process of determining the write field stitching error applicable to large-size lithography pattern stitching. After the write field stitching error is determined, these errors can be eliminated by position compensation in formal lithography, thereby achieving seamless stitching of the write field.

[0079] Fig.11 1 is a schematic flow chart describing a lithography method 1100 for a multi-probe lithography apparatus according to various embodiments of the present invention. Figure 1 As described, it includes a plurality of probe groups that can move independently relative to each other, wherein each probe group may include one or more probes. Method 1100 starts at step 1102, dividing the pattern to be photolithographic into a plurality of sub-patterns, each sub-pattern corresponding to the write field of a single probe. As an example, in a scenario where the write field of a single probe is a rectangular write field, the pattern to be photolithographic can be divided into grids, each grid corresponding to a rectangular write field. In the case where the pattern to be photolithographic is a circle, the pattern to be photolithographic can also be divided into grids in radial and tangential directions, each grid corresponding to the write field of a probe that also moves radially and tangentially. For example, the pattern to be photolithographic can be divided into 64*64 square write fields.

[0080] In step 1104, the exposure order of the multiple sub-patterns is determined. The exposure order indicates the probe that performs the exposure of each sub-pattern and the movement order of each probe. For large-size pattern lithography, the pattern to be lithographically processed can be lithographically processed by probes in at least two probe groups at the same time, and the distance between any two adjacent probe groups in the multiple probe groups is greater than the size of the write field of a single probe. As a non-limiting example, when determining the exposure order, it is also necessary to consider how to arrange the probe groups, including the number of probes in each probe group, the arrangement of each probe group, etc., as described in the previous embodiments. This can usually be comprehensively considered based on the shape and size of the pattern to be lithographically processed, the write field and size of the probe, the performance and size of the workbench (such as the number of supported beams, the number of cantilevers, etc.), process requirements (such as the speed at which the overall lithography of the wafer is expected to be completed), manufacturing cost, stability and other factors to maximize the overall efficiency and speed of the lithography project. The exposure order finally determined will at least include information such as the order in which the write fields are exposed in sequence, the route of the probe movement, and which write fields are exposed in each write field exposure cycle (this implies the number of probe groups and the number of probes in a single probe group). For example, for Fig.12 In the example pattern composed of 16*16 square writing fields shown in , 2 probe groups are arranged, each probe group includes 2 probes, and the probe groups are horizontally distributed in a row, separated by 6 writing fields. Starting from the leftmost side of the first row, in the first exposure cycle, 4 probes are exposed at the same time, that is, the 1st-2nd and 9th-10th writing fields of the first row are exposed, and then the probes are moved out. In the next exposure cycle, the 3rd-4th and 11th-12th writing fields of the first row are exposed, and so on. After the first row is completed, it can move down to the second row, perform the exposure of the 7th-8th and 15th-16th writing fields of the second row, and then move to the left, thus moving in a snake shape until all 16*16 writing fields are exposed.

[0081] In step 1106, the relative position of each probe group in the plurality of probe groups is initialized according to the exposure sequence. According to the exposure sequence determined in the previous step, it can be determined how many probe groups need to be used, the number of probes in each probe group, and the initial position of each probe group. Subsequently, each probe group needs to be initialized, including moving each probe group to the initial exposure position determined by the exposure sequence and determining the write field stitching error within each probe group and the write field stitching error between adjacent probe groups. The specific method for determining the internal and external write field stitching errors of the probe group has been described in detail in the previous embodiment. After determining the write field stitching errors within the group and the assembly, each probe can be adjusted in position according to these stitching errors to compensate for these errors.

[0082] In step 1108, the pattern to be photolithographically exposed is exposed according to the exposure sequence. After compensation, the probe group can perform formal exposure of each writing field in sequence according to the exposure sequence until the exposure of the entire large-size photolithographic pattern is completed.

[0083] Preferred embodiments of the present invention have been described above in detail, but it should be understood that aspects of the embodiments can be modified, if necessary, to employ aspects, features and concepts of the various patents, applications and publications to provide further embodiments.

[0084] These and other changes can be made to the embodiments in light of the above detailed description.In general, in the claims, the terms used should not be considered limited to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which these claims are entitled.

Claims

1. A lithography method for a multi-probe lithography apparatus, characterized in that: The multi-probe lithography apparatus comprises a plurality of exposure unit groups that are independently movable relative to each other, each exposure unit group comprises one or more exposure units, and the method comprises: Divide the pattern to be photolithographic into a plurality of sub-patterns, each sub-pattern corresponding to a writing field of a single exposure unit; Determining an exposure sequence of the plurality of sub-patterns, wherein the exposure sequence indicates an exposure unit for performing exposure of each sub-pattern and a moving sequence of each exposure unit, wherein the pattern to be photolithographically lithographed by exposure units in at least two exposure unit groups at the same time, and a distance between any two adjacent exposure unit groups in the plurality of exposure unit groups is greater than a size of a writing field of a single exposure unit; Initializing a relative position of each of the plurality of exposure unit groups according to the exposure sequence; and Exposure of the image to be photolithographically processed is performed according to the exposure sequence.

2. The photolithography method according to claim 1, wherein: Initializing the relative position of each of the plurality of exposure unit groups according to the exposure sequence further comprises: According to the exposure sequence, each exposure unit group is moved to a corresponding initial exposure position; Determine the intra-group writing field stitching error of each exposure unit group and the inter-group writing field stitching error between adjacent exposure unit groups; and The positions of the exposure unit groups are adjusted to compensate for the determined intra-group writing field stitching errors and inter-group writing field stitching errors.

3. The photolithography method according to claim 2, wherein: Determining the intra-group writing field stitching error of each exposure unit group and the inter-group writing field stitching error between adjacent exposure unit groups further includes: Each exposure unit in the exposure unit group: Exposure indicates the first writing field mark of the current writing field range; Observe whether there is a second writing field mark exposed by other exposure units in the observation range of the exposure unit; In the case where there is a second write field mark, determining a second write field range corresponding to the second write field mark; determining whether the second write field mark is exposed by an exposure unit in the same exposure unit group or by an exposure unit in a different exposure unit group; If the second writing field mark is exposed by an exposure unit of the same exposure unit group, measuring a writing field stitching error based on the current writing field range and the second writing field range, and recording it as a writing field stitching error within the group, moving to the next writing field according to the exposure sequence, and repeating the above steps; and If the second writing field mark is exposed by an exposure unit of a different exposure unit group, a writing field stitching error is measured based on the current writing field range and the second writing field range, and recorded as the inter-group writing field stitching error.

4. The photolithography method according to claim 3, characterized in that: Adjusting the positions of the exposure unit groups to compensate for the determined intra-group writing field stitching errors and inter-group writing field stitching errors further includes: According to the intra-group writing field stitching error and the inter-group writing field stitching error recorded by the exposure units of each exposure unit group, the position of each exposure unit in each exposure unit group is adjusted to compensate for the intra-group writing field stitching error and the inter-group writing field stitching error.

5. The photolithography method according to claim 4, characterized in that: The multiple exposure unit groups are configured to move in two moving dimensions orthogonal to each other on a working plane parallel to the wafer, and each exposure unit in the exposure unit group is configured to be able to perform scanning exposure in two scanning dimensions orthogonal to each other on the working plane parallel to the wafer, and the two scanning dimensions are respectively parallel to the two moving dimensions.

6. The photolithography method according to claim 5, characterized in that: The two movement dimensions are the horizontal axis and the vertical axis in a Cartesian coordinate system.

7. The photolithography method according to claim 5, characterized in that: The two movement dimensions are radial and tangential to the circle.

8. The photolithography method according to claim 7, wherein: Each exposure unit group moves to a corresponding initial exposure position further comprising: Selecting one of the plurality of exposure unit groups whose initial exposure positions are on the same circumference as a reference exposure unit group; An exposure unit in the reference exposure unit group exposes a reference circular line along a tangential direction; The remaining exposure unit groups in the plurality of exposure unit groups adjust their positions to the reference circumferential line based on the reference circumferential line; and Each exposure unit group is moved to a corresponding initial exposure position along the reference circumferential line.

9. The photolithography method according to claim 8, wherein: Initializing the relative position of each of the plurality of exposure unit groups according to the exposure sequence further comprises: Each exposure unit scanner is calibrated so that its two scanning dimensions are parallel to the radial and tangential directions of the circle, respectively.

10. The photolithography method according to claim 9, wherein: Calibration of each exposure unit so that its two scanning dimensions are parallel to the radial direction and the tangential direction of the circle further comprises: The exposure unit to be calibrated exposes a mark on the reference circumferential line as a reference point; Moving a predetermined distance toward the center of the circle along a first scanning dimension of the two scanning dimensions that is expected to be parallel to the radial direction of the circle; Exposing a straight line along a second scanning dimension of the two scanning dimensions that is expected to be parallel to the tangent direction of the circle, so that the straight line intersects the circumference line at a first point and a second point; measuring the length of a first arc between the first point and the reference point and the length of a second arc between the second point and the reference point; The exposure unit to be calibrated returns to the reference point and rotates by a certain angle along its own axis according to a comparison result between the lengths of the first arc and the second arc; and Repeat the above steps until the lengths of the first arc and the second arc are equal.

11. A multi-probe lithography apparatus, comprising: Wafer worktable, used to carry wafers to be photolithographically processed; An exposure system, wherein the exposure system comprises a plurality of exposure unit groups, each of which comprises one or more exposure units; as well as A control unit, wherein the control unit is used to control the exposure system to perform the photolithography method as described in any one of claims 1 to 10 to expose the wafer carried on the wafer workbench.

12. The multi-probe lithography apparatus according to claim 11, characterized in that: The exposure unit uses any of the following types as an exposure source: Electron beams emitted via high voltage fields; An electron beam is emitted through heating of the filament; an electron beam emitted through a probe field; Thermal radiation via heating of the probe tip; or Laser beam.

13. The multi-probe lithography apparatus according to claim 11, wherein: The plurality of exposure unit groups are arranged in any one of the following arrangements on a plane parallel to the wafer worktable: The Cartesian coordinate system is arranged orthogonally; The Cartesian coordinate system is arranged in an orthogonal manner; The Cartesian coordinate system is arranged parallel at an angle; The radial coordinate system is arranged radially along the coaxial circumference; or The radial coordinate system is arranged along the same circle.

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