A method and device for determining alignment marks of a wafer

Abstract

The present application provides a method and an apparatus for determining alignment marks on a wafer. The determining method includes: obtaining the mark types and mark qualities of the alignment marks provided on each alignment mark unit on the target wafer; combining according to the obtained mark types and mark qualities of each alignment mark to obtain the category identifier of each alignment mark; determining the category combination identifier of each alignment mark combination; aiming at the shortest moving path of the moving stage, determining the alignment order of the alignment marks aligned by the moving stage under each category identifier or each category combination identifier; and pairing the alignment marks according to the pre-determined number of pairs according to the determined alignment order to obtain the target alignment marks of the target wafer. Through the determining method and the determining apparatus, alignment marks that can make the wafer stage move a shorter distance can be selected, thereby improving the efficiency of manufacturing chips and reducing the cost required for manufacturing chips.

Description

Technical Field

[0001] The present application relates to the field of integrated circuit manufacturing, and more particularly, to a method and apparatus for determining alignment marks on a wafer. Background Art

[0002] In the field of integrated circuit manufacturing, transferring the pattern on a mask onto a wafer in a certain proportion by semiconductor process equipment is the most critical process for manufacturing chips. In this process, since the surface of the wafer is uneven and there are also alignment deviations in the equipment, certain deviations will occur when transferring the pattern on the mask onto the wafer during the exposure process. Therefore, it is usually necessary to determine the surface profile data of the wafer surface through the alignment marks on the wafer, so that the pattern on the mask can be accurately transferred to the corresponding position on the wafer according to the surface profile data.

[0003] In the existing method for selecting wafer alignment marks, usually the alignment marks are selected in sequence according to their arrangement order. However, this selection method will cause the moving stage carrying the wafer to move a relatively long distance, reducing the production efficiency of manufacturing chips. Summary of the Invention

[0004] In view of this, the purpose of the embodiments of the present application is to provide a method and apparatus for determining alignment marks on a wafer. Through the mark type, mark quality, and nominal coordinates of the alignment marks on the wafer, alignment marks that can make the wafer stage move a smaller distance can be selected, thereby improving the efficiency of manufacturing chips and reducing the cost required for manufacturing chips.

[0005] In a first aspect, an embodiment of the present application provides a method for determining alignment marks on a wafer, characterized in that the wafer includes a plurality of exposure blocks, each exposure block includes at least one alignment mark unit, and each alignment mark unit is provided with an alignment mark; the alignment mark includes at least one X mark parallel to the horizontal direction X axis and / or at least one Y mark parallel to the vertical direction Y axis; the determination method includes:

[0006] Obtaining the mark type and mark quality of the alignment marks provided on each alignment mark unit on the target wafer; the mark type includes XY type, X type, and Y type; the XY type is a type in which the alignment mark includes at least one X mark and at least one Y mark at the same time; the X type is a type in which the alignment mark only includes at least one X mark; the Y type is a type in which the alignment mark only includes at least one Y mark; the mark quality is used to evaluate the quality of the X mark and / or Y mark on each alignment mark; the mark quality includes A quality and B quality;

[0007] Combining according to the mark type and mark quality of each obtained alignment mark to obtain the category identifier of each alignment mark; the category identifier includes any one of the following items: mark type is XY type and mark quality is A, mark type is XY type and mark quality is B, mark type is X type and mark quality is A, mark type is X type and mark quality is B, mark type is Y type and mark quality is A, mark type is Y type and mark quality is B;

[0008] Combining an alignment mark of mark type X and an alignment mark of mark type Y on each exposure block to obtain an alignment mark combination on each exposure block; and combining the category identifiers of each alignment mark in the alignment mark combination on each exposure block to obtain the category combination identifier of each alignment mark combination; the category combination identifier includes any one of the following items: mark type is X type and mark quality is A and mark type is Y type and mark quality is A, mark type is X type and mark quality is A and mark type is Y type and mark quality is B, mark type is X type and mark quality is B and mark type is Y type and mark quality is A, mark type is X type and mark quality is B and mark type is Y type and mark quality is B;

[0009] Taking the shortest moving path of the moving stage as the goal, determining the alignment order of the alignment marks aligned by the moving stage under each category identifier or each category combination identifier;

[0010] According to the determined alignment order, pairing the alignment marks according to the pre-determined number of pairs to obtain the target alignment marks of the target wafer.

[0011] Optionally, the determination method further includes:

[0012] Determining the coordinate deviation between the nominal coordinate and the actual coordinate of each target alignment mark;

[0013] Determining the sum of the coordinate deviations of all target alignment marks, and determining the alignment deviation of the target wafer based on the sum of the coordinate deviations; the alignment deviation is used for wafer alignment.

[0014] Optionally, the step of taking the shortest moving path of the moving stage as the goal and determining the order of the alignment marks aligned by the moving stage under each category identifier or category combination identifier includes:

[0015] In the order of preferentially processing alignment marks and then processing alignment mark combinations, respectively determining the alignment order of all alignment marks when the moving stage aligns all alignment marks with the shortest moving path for alignment marks, and determining the alignment order of all alignment mark combinations when the moving stage aligns all alignment mark combinations with the shortest path for alignment mark combinations;

[0016] Optionally, when determining the shortest path for the moving stage to align all alignment marks for the alignment marks, the alignment order of all alignment marks includes: according to the determined order of the category identifiers, for the alignment marks under each category identifier, when determining the shortest moving path for the moving stage to align all alignment marks under this category identifier, the order of the alignment marks under this category identifier;

[0017] When determining the shortest moving path for the moving stage to align all combinations of alignment marks for the combination of alignment marks, the alignment order of all combinations of alignment marks includes:

[0018] According to the determined order of the category combination identifiers, for the alignment marks under each category combination identifier, when determining the shortest path for the moving stage to align all alignment marks under this category combination identifier, the order of the combination of alignment marks under this category combination identifier;

[0019] Wherein, when the mark type is XY type and the mark quality is A, if the number of alignment marks under this category identifier is odd, the alignment mark with the shortest distance from the last alignment mark in the category identifier of XY type and mark quality A in the mark type of XY type and mark quality B is used as the first alignment mark of the mark type of XY type and mark quality B to be aligned by the moving stage;

[0020] When the mark type is XY type and the mark quality is B, if the number of alignment marks under this category identifier is odd, the penultimate alignment mark under this category identifier is used as the last alignment mark of the mark type of XY type and mark quality B to be aligned by the moving stage, and the alignment mark with the shortest distance from the last alignment mark in the category identifier of XY type and mark quality B in the mark type of X type and mark quality A or the mark type of Y type and mark quality A is used as the first alignment mark of the mark type of X type and mark quality A or the first alignment mark of the mark type of Y type and mark quality A to be aligned by the moving stage.

[0021] Optionally, the order of the alignment marks under the category identifier when, according to the determined order of the category identifier, for the alignment marks under each category identifier, determining the shortest path for the moving stage to align all alignment marks under this category identifier includes:

[0022] According to the determined order of the category identifier, for the alignment marks under each category identifier, based on the nominal coordinates of each alignment mark, determine the first mark distance between every two alignment marks;

[0023] Take the alignment mark pairs with the first mark distance greater than the preset threshold as the expected alignment mark pairs, and starting from the position of the workpiece stage, determine the second mark distance from the position of the workpiece stage to the alignment mark in each expected alignment mark pair that is the closest to the position of the workpiece stage; where the closest distance does not include a distance of zero;

[0024] Take the expected alignment mark pair corresponding to the minimum sum value of the second mark distance and the first mark distance as the target alignment mark pair;

[0025] Sort the order of the alignment marks in the target alignment mark pair according to the path of the moving stage movement to determine the alignment order of the alignment marks under this category identifier.

[0026] Optionally, the method for determining the length of the moving path includes:

[0027] If processing alignment marks, determine the Euclidean distance between every two alignment marks as the length of the moving path;

[0028] If processing alignment mark combinations, determine the Manhattan distance between every two alignment marks as the length of the moving path.

[0029] Optionally, the pairing of alignment marks according to the determined alignment order according to the pre-determined number of pairings to obtain the target alignment marks of the target wafer includes:

[0030] Search downward in the alignment marks for alignment marks with a different mark type from the previous alignment mark according to the determined alignment order;

[0031] Take the position between the alignment mark with a different mark type from the previous alignment mark and the previous alignment mark as the split point, and pair the alignment marks before the split point in pairs according to the determined alignment order to obtain the initial number of pairings;

[0032] Compare the initial number of pairings with the pre-determined number of pairings;

[0033] If the comparison result is that the initial number of pairings is less than the pre-determined number of pairings, then pair the alignment marks after the split point every four according to the determined alignment order to obtain the second number of pairings;

[0034] Determine whether the sum of the initial number of pairings and the second number of pairings is equal to the pre-determined number of pairings;

[0035] If the sum of the initial number of pairings and the second number of pairings is equal to the pre-determined number of pairings, then take the alignment marks paired before the split point and the alignment marks paired after the split point as the target alignment marks of the target wafer.

[0036] In a second aspect, an embodiment of the present application provides a device for determining alignment marks of a wafer, characterized in that the determining device includes:

[0037] An acquisition module that acquires the mark type and mark quality of the alignment marks set on each alignment mark unit on a target wafer; the mark types include XY type, X type, and Y type; the XY type is a type in which the alignment mark includes at least one X mark and at least one Y mark at the same time; the X type is a type in which the alignment mark only includes at least one X mark; the Y type is a type in which the alignment mark only includes at least one Y mark; the mark quality is used to evaluate the quality of the X mark and / or Y mark on each alignment mark; the mark quality includes A quality and B quality;

[0038] A category identification determination module that combines the mark type and mark quality of each acquired alignment mark to obtain the category identification of each alignment mark; the category identification includes any one of the following items: the mark type is XY type and the mark quality is A, the mark type is XY type and the mark quality is B, the mark type is X type and the mark quality is A, the mark type is X type and the mark quality is B, the mark type is Y type and the mark quality is A, the mark type is Y type and the mark quality is B;

[0039] A category combination identification determination module that combines an alignment mark of X type and an alignment mark of Y type on each exposure block to obtain an alignment mark combination on each exposure block; and combines the category identifications of each alignment mark in the alignment mark combination on each exposure block to obtain the category combination identification of each alignment mark combination; the category combination identification includes any one of the following items: the mark type is X type and the mark quality is A and the mark type is Y type and the mark quality is A, the mark type is X type and the mark quality is A and the mark type is Y type and the mark quality is B, the mark type is X type and the mark quality is B and the mark type is Y type and the mark quality is A, the mark type is X type and the mark quality is B and the mark type is Y type and the mark quality is B;

[0040] An alignment order determination module that takes the shortest movement path of the moving stage as the goal and determines the alignment order of the alignment marks aligned by the moving stage under each category identification or each category combination identification;

[0041] A target alignment mark determination module that pairs the alignment marks according to the determined alignment order and the pre-determined pairing quantity to obtain the target alignment marks of the target wafer.

[0042] In a third aspect, an embodiment of the present application further provides an electronic device, including: a processor, a memory, and a bus, the memory stores machine-readable instructions executable by the processor, when the electronic device runs, the processor communicates with the memory through the bus, and when the machine-readable instructions are executed by the processor, the steps in the above first aspect, or any possible implementation manner in the first aspect are executed.

[0043] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is run by a processor, the steps in the above first aspect or any possible implementation manner in the first aspect are executed.

[0044] A method and device for determining alignment marks of a wafer provided by an embodiment of the present application can select an alignment mark that makes the wafer stage move a smaller distance through the mark type, mark quality, and nominal coordinates of the alignment mark of the wafer, thereby improving the efficiency of manufacturing chips and reducing the cost required for manufacturing chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0046] Figure 1 Shows a flowchart of a method for determining alignment marks of a wafer provided by an embodiment of the present application;

[0047] Figure 2 Shows a flowchart of a method for determining the order of alignment marks under each category identifier;

[0048] Figure 3 Shows a schematic diagram of the order of alignment marks under a category identifier when the moving stage aligns all alignment marks under the category identifier with the shortest path when the category identifier is XY for the mark type and A for the mark quality;

[0049] Figure 4 Shows a method for determining a target alignment mark of a target wafer provided by an embodiment of the present application;

[0050] Figure 5 Shows a schematic structural diagram of a device for determining alignment marks of a wafer provided by an embodiment of the present application;

[0051] Figure 6 Shows a schematic structural diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Apparently, the described embodiments are only some of the embodiments of this application, rather than all of them. Usually, the components of the embodiments of this application described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents the selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative efforts fall within the scope of protection of this application.

[0053] See Figure 1 as shown Figure 1 It is a flowchart of a method for determining alignment marks on a wafer provided by an embodiment of this application.

[0054] The wafer includes a plurality of exposure blocks, each exposure block includes at least one alignment mark unit, and each alignment mark unit is provided with an alignment mark; the alignment mark includes at least one X mark parallel to the horizontal X axis and / or at least one Y mark parallel to the vertical Y axis.

[0055] As an example, the alignment mark includes at least one X mark parallel to the horizontal X axis. For example, the alignment mark includes three X marks parallel to the horizontal X axis; as another example, the alignment mark includes at least one Y mark parallel to the vertical Y axis. For example, the alignment mark includes three Y marks parallel to the vertical Y axis; as another example, the alignment mark includes at least one X mark parallel to the horizontal X axis and at least one Y mark parallel to the vertical Y axis.

[0056] As Figure 1 shown, a method for determining alignment marks on a wafer provided by an embodiment of this application includes the following steps:

[0057] S101. Obtain the mark type and mark quality of the alignment marks set on each alignment mark unit on the target wafer.

[0058] The mark type includes XY type, X type, and Y type; the XY type is the type where the alignment mark includes at least one X mark and at least one Y mark at the same time; the X type is the type where the alignment mark only includes at least one X mark; the Y type is the type where the alignment mark only includes at least one Y mark; the mark quality is used to evaluate the quality of the X mark and / or Y mark on each alignment mark; the mark quality includes A and B; the A quality is the mark quality that meets the clarity condition, and the B quality is the mark quality that does not meet the clarity condition.

[0059] S102. Combine according to the marker type and marker quality of each obtained alignment marker to obtain the category identifier of each alignment marker.

[0060] The category identifier includes any one of the following items: marker type is XY type and marker quality is A, marker type is XY type and marker quality is B, marker type is X type and marker quality is A, marker type is X type and marker quality is B, marker type is Y type and marker quality is A, marker type is Y type and marker quality is B.

[0061] S103. Combine an alignment marker of marker type X and an alignment marker of marker type Y on each exposure block to obtain an alignment marker combination on each exposure block; and combine the category identifiers of each alignment marker in the alignment marker combination on each exposure block to obtain the category combination identifier of each alignment marker combination.

[0062] The category combination identifier includes any one of the following items: marker type is X type and marker quality is A and marker type is Y type and marker quality is A, marker type is X type and marker quality is A and marker type is Y type and marker quality is B, marker type is X type and marker quality is B and marker type is Y type and marker quality is A, marker type is X type and marker quality is B and marker type is Y type and marker quality is B.

[0063] Here, because both X markers and Y markers are required in the process of determining the coordinate deviation between the nominal coordinates and the actual coordinates of each target alignment marker, for XY type alignment markers, only one XY type alignment marker is needed each time when determining the coordinate deviation. However, since there is only an X marker on the alignment marker of marker type X and only a Y marker on the alignment marker of marker type Y, for the alignment markers of X type and Y type, one alignment marker of X type and one alignment marker of Y type are required simultaneously each time when determining the coordinate deviation.

[0064] Under the above objectively existing conditions, combine an alignment marker of marker type X and an alignment marker of marker type Y on each exposure block to obtain an alignment marker combination on each exposure block.

[0065] S104. With the goal of the shortest moving path of the moving stage, determine the alignment order of the alignment markers aligned by the moving stage under each category identifier or category identifier combination.

[0066] Exemplarily, in this step, in the order of first processing the alignment marks and then processing the combination of alignment marks, when determining the shortest movement path of the moving stage to align all the alignment marks for the alignment marks respectively, the alignment order of all the alignment marks is determined, and when determining the shortest path for the moving stage to align all the combinations of alignment marks for the combination of alignment marks, the alignment order of all the combinations of alignment marks is determined;

[0067] Here, since the XY-type alignment marks can calculate the deviation of the wafer more accurately than the X-type and Y-type alignment marks, the alignment marks are processed first, and then the combination of alignment marks is processed.

[0068] Exemplarily, when processing the alignment marks, in the order of determination of the category identifier, for the alignment marks under each category identifier, when determining the shortest movement path of the moving stage to align all the alignment marks under this category identifier, the order of the alignment marks under this category identifier is determined.

[0069] Here, the order of determination of the category identifier is to first process the category identifier with the mark type of XY and the mark quality of A in the category identifier, and then process the category identifier with the mark type of XY and the mark quality of B.

[0070] Exemplarily, when processing the combination of alignment marks, in the order of determination of the category combination identifier, for the alignment marks under each category combination identifier, when determining the shortest path for the moving stage to align all the alignment marks under this category combination identifier, the order of the combination of alignment marks under this category combination identifier is determined.

[0071] Here, the order of determination of the category combination identifier is to first process the category combination identifier with the mark type of X and the mark quality of A and the mark type of Y and the mark quality of A in the category combination identifier, and then simultaneously process the category combination identifier with the mark type of X and the mark quality of A and the mark type of Y and the mark quality of B, the category combination identifier with the mark type of X and the mark quality of B and the mark type of Y and the mark quality of A, and finally process the category combination identifier with the mark type of X and the mark quality of B and the mark type of Y and the mark quality of B.

[0072] Among them, when the mark type is XY and the mark quality is A, if the number of alignment marks under this category identifier is odd, the alignment mark with the shortest distance from the last alignment mark in the category identifier with the mark type of XY and the mark quality of A among the alignment marks with the mark type of XY and the mark quality of B is used as the first alignment mark with the mark type of XY and the mark quality of B to be aligned by the moving stage.

[0073] When the mark type is XY type and the mark quality is B, if the number of alignment marks under this category identifier is odd, the penultimate alignment mark under this category identifier is used as the last alignment mark of type XY and mark quality B that the moving stage aligns with, and the alignment mark with the shortest distance from the last alignment mark in the category identifier of type XY and mark quality B among the alignment marks of type X and mark quality A or type Y and mark quality A is used as the first alignment mark of type X and mark quality A or the first alignment mark of type Y and mark quality A that the moving stage aligns with.

[0074] When the mark types are X type and mark quality A and Y type and mark quality A, if the number of the alignment mark combinations under this mark category combination identifier is odd, the alignment mark combination with the shortest distance from the last alignment mark combination of type X and mark quality A and type Y and mark quality A among the combinations of type X and mark quality A and type Y and mark quality B, or the combinations of type X and mark quality B and type Y and mark quality A, is used as the first alignment mark combination of type X and mark quality A and type Y and mark quality B, or the alignment mark combination of type X and mark quality B and type Y and mark quality A that the moving stage aligns with.

[0075] For the alignment mark combinations of type X and mark quality A and type Y and mark quality B, type X and mark quality B and type Y and mark quality A, and type X and mark quality B and type Y and mark quality B, the first and last alignment mark combinations under each category combination identifier are obtained in the same way.

[0076] Exemplarily, the following will be combined with Figure 2 to introduce how to determine the order of the alignment marks under each category identifier when processing the alignment marks, so that when the moving stage aligns with all the alignment marks under this category identifier with the shortest moving path, the order of the alignment marks under this category identifier.

[0077] Figure 2 Fig. shows a flowchart for determining the order of the alignment marks under each category identifier provided by an embodiment of the present application.

[0078] As Figure 2 shown, in step S1041, according to the determined order of the category identifiers, for the alignment marks under each category identifier, the first mark distance between every two alignment marks is determined according to the nominal coordinates of each alignment mark.

[0079] Here, for alignment marks of the XY type, for alignment marks identified by different category identifiers, when the stage aligns each alignment mark among all the alignment marks under the category identifier, the alignment marks need to come from different exposure blocks from other alignment marks. For example, if there are a total of 9 exposure blocks on the wafer, and there are 2 alignment marks of the XY type with a mark quality of A on the first exposure block, and there are also 2 alignment marks of the XY type with a mark quality of A on the second exposure block, then only one alignment mark of the XY type with a mark quality of A can be aligned on the first exposure block, and the next alignment mark that the stage needs to align is one of the alignment marks of the XY type with a mark quality of A on the second exposure block.

[0080] Step S1042: Use the alignment marks with the first mark distance greater than the preset threshold as the expected alignment mark pairs. Starting from the position of the workpiece stage, determine the second mark distance from the position of the workpiece stage to the alignment mark closest to the workpiece stage position in each expected alignment mark pair; where the closest distance does not include a distance of zero.

[0081] Step S1043: Use the expected alignment mark pair corresponding to the smallest sum value of the second mark distance and the first mark distance as the target alignment mark pair.

[0082] Step S1044: Sort the alignment marks in the target alignment mark pair according to the path of the minimum distance of the stage movement to determine the alignment order of the alignment marks under the category identifier.

[0083] In step S105: According to the determined alignment order, pair the alignment marks according to the pre-determined number of pairs to obtain the target alignment marks of the target wafer.

[0084] Next, it will be combined with Figure 3 to introduce how to determine the order of the alignment marks under each category identifier.

[0085] Figure 3 Fig. shows a schematic diagram of the order of alignment marks under a category identifier when the stage aligns all alignment marks under the category identifier with the shortest path when the category identifier is the mark type XY and the mark quality is A provided by an embodiment of the present application.

[0086] As Figure 3 shown, there are a total of 9 exposure blocks in the entire exposure field of the target wafer. Each exposure block includes 4 alignment mark units. The mark types of the alignment marks on all exposure blocks are arranged repeatedly. There are a total of 5 alignment marks of the XY type with a mark quality of A among all the alignment mark units in the entire exposure field of the wafer.

[0087] First, select alignment marks with a category identifier of XY type and a mark quality of A from all alignment marks. Then, based on the nominal coordinates of the alignment marks under each such category identifier, determine the first mark distance between every two alignment marks of this category identifier. Here, the number of the first mark distances is Then, take the alignment marks with the first mark distance greater than the preset threshold as the desired alignment mark pairs. For example, if the distance between XYA1 and XYA3 is greater than the preset threshold, and the distance between XYA4 and XYA2 is greater than the preset threshold, then take XYA1 and XYA3 as the first desired alignment mark pair, and XYA4 and XYA2 as the second desired alignment mark pair. If the position of the worktable is at the position of point O, then determine the alignment marks closest to the position of point O among the first desired alignment mark pair XYA1 and XYA3 and the second desired alignment mark pair XYA4 and XYA2, that is, the distances from point O to XYA1 and XYA2. If the sum of the distance from point O to XYA1 and the distance from point O to XYA3 is less than the sum of the distance from point O to XYA2 and the distance from XYA2 to XYA4, then take the first desired alignment mark pair XYA1 and XYA3 as the target alignment mark pair. Then, sort the alignment marks in the alignment mark pair according to the path of the minimum distance of the moving stage movement to determine the alignment order of the desired alignment marks XYA1 - XYA3. Then, execute the above process again to obtain the alignment order of the alignment marks under this category identifier in turn.

[0088] Next, in combination with Figure 4 it will be introduced how to determine the target alignment mark of the target wafer.

[0089] Figure 4 It shows a method for determining the target alignment mark of the target wafer provided by an embodiment of the present application.

[0090] As Figure 4 shown, in step S1051, search downward in the alignment marks for an alignment mark with a mark type different from that of the previous alignment mark according to the determined alignment order.

[0091] In step S1052, take the position between the alignment mark with a mark type different from that of the previous alignment mark and the previous alignment mark as the segmentation point, and pair up the alignment marks before the segmentation point in pairs according to the determined alignment order to obtain the initial pairing number.

[0092] In step S1053, determine whether the initial pairing number is less than the pre-determined pairing number.

[0093] In step 1054, if the initial pairing number is less than the pre-determined pairing number, then pair up the alignment marks after the segmentation point every four according to the determined alignment order to obtain the second pairing number.

[0094] In step S1055, determine whether the sum of the initial pairing quantity and the second pairing quantity is equal to a predetermined pairing quantity;

[0095] In step S1056, if the sum of the initial pairing quantity and the second pairing quantity is equal to the predetermined pairing quantity, then use the alignment marks that have been paired before the split point and the alignment marks that have been paired after the split point as the target alignment marks of the target wafer.

[0096] Exemplarily, if the target alignment marks are determined in step S105, then determine the coordinate deviation between the nominal coordinate and the actual coordinate of each target alignment mark; determine the sum of the coordinate deviations of all target alignment marks, and determine the alignment deviation of the target wafer based on the sum of the coordinate deviations; the alignment deviation is used for wafer alignment.

[0097] A method and a determining device for determining alignment marks of a wafer provided by an embodiment of the present application can select alignment marks that make the wafer stage move a smaller distance through the mark type, mark quality, and nominal coordinates of the alignment marks of the wafer, thereby improving the efficiency of manufacturing chips and reducing the cost required for manufacturing chips.

[0098] Based on the same inventive concept, an embodiment of the present application also provides a determining device for alignment marks of a wafer corresponding to the method for determining alignment marks of a wafer.

[0099] See Figure 5 as shown in Figure 5 A schematic structural diagram of a determining device for alignment marks of a wafer provided by an embodiment of the present application. The determining device 510 for alignment marks of a wafer includes:

[0100] An obtaining module 511, configured to obtain the mark type and mark quality of the alignment marks set on each alignment mark unit on the target wafer; the mark type includes XY type, X type, and Y type; the XY type is a type in which the alignment mark includes at least one X mark and at least one Y mark at the same time; the X type is a type in which the alignment mark only includes at least one X mark; the Y type is a type in which the alignment mark only includes at least one Y mark; the mark quality is used to evaluate the quality of the X mark and / or Y mark on each alignment mark; the mark quality includes A quality and B quality.

[0101] A category identification determination module 512, configured to combine the obtained mark type and mark quality of each alignment mark to obtain the category identification of each alignment mark; the category identification includes any one of the following items: the mark type is XY type and the mark quality is A, the mark type is XY type and the mark quality is B, the mark type is X type and the mark quality is A, the mark type is X type and the mark quality is B, the mark type is Y type and the mark quality is A, the mark type is Y type and the mark quality is B.

[0102] A category combination identification determination module 513, which combines an alignment mark of X type and an alignment mark of Y type on each exposure block to obtain an alignment mark combination on each exposure block; and combines the category identifications of each alignment mark in the alignment mark combination on each exposure block to obtain the category combination identification of each alignment mark combination; the category combination identification includes any one of the following items: the mark type is X type and the mark quality is A and the mark type is Y type and the mark quality is A, the mark type is X type and the mark quality is A and the mark type is Y type and the mark quality is B, the mark type is X type and the mark quality is B and the mark type is Y type and the mark quality is A, the mark type is X type and the mark quality is B and the mark type is Y type and the mark quality is B.

[0103] An alignment order determination module 514, with the goal of the shortest movement path of the moving stage, determines the alignment order of the alignment marks aligned by the moving stage under each category identification or each category combination identification.

[0104] A target alignment mark determination module 515, according to the determined alignment order and the pre-determined pairing quantity, pairs the alignment marks to obtain the target alignment marks of the target wafer.

[0105] In a possible implementation manner, the alignment order determination module 514 is specifically configured to: in the order of preferentially processing alignment marks and then processing alignment mark combinations, respectively determine the alignment order of all alignment marks when the moving stage aligns all alignment marks with the shortest movement path for the alignment marks, and determine the alignment order of all alignment mark combinations when the moving stage aligns all alignment mark combinations with the shortest path for the alignment mark combinations.

[0106] In a possible implementation manner, when the above alignment order determination module 514 is used to determine the alignment order of all alignment marks when the moving stage aligns all alignment marks with the shortest movement path for the alignment marks, it is specifically configured to: according to the determination order of the category identifications, for the alignment marks under each category identification, determine the order of the alignment marks under the category identification when the moving stage aligns all alignment marks under the category identification with the shortest movement path.

[0107] In a possible implementation manner, when the alignment order determination module 514 is used to determine the shortest moving path for the moving stage to align all alignment mark combinations for an alignment mark combination and the alignment order of all alignment mark combinations, it is specifically configured to: according to the determination order of the category combination identifier, for the alignment marks under each category combination identifier, when determining the shortest path for the moving stage to align all alignment marks under this category combination identifier, determine the order of the alignment mark combination under this category combination identifier.

[0108] In a possible implementation manner, when the alignment order determination module 514 is used to, according to the determination order of the category identifier, for the alignment marks under each category identifier, determine the shortest path for the moving stage to align all alignment marks under this category identifier and the order of the alignment marks under this category identifier, it is specifically configured to, according to the determination order of the category identifier, for the alignment marks under each category identifier, determine the first mark distance between every two alignment marks according to the nominal coordinates of each alignment mark.

[0109] Take the alignment marks with the first mark distance greater than the preset threshold as the expected alignment mark pairs, and starting from the position where the workpiece stage is located, determine the second mark distance from the position where the workpiece stage is located to the alignment mark closest to the position where the workpiece stage is located in each expected alignment mark pair; where the closest distance does not include a distance of zero.

[0110] Take the expected alignment mark pair corresponding to the minimum sum value of the second mark distance and the first mark distance as the target alignment mark pair.

[0111] Sort the order of the alignment marks in the target alignment mark pair according to the path of the moving stage movement, and determine the alignment order of the alignment marks under this category identifier.

[0112] In a possible implementation manner, the above-mentioned alignment order determination module 514 is further configured to:

[0113] If processing alignment marks, determine the Euclidean distance between every two alignment marks as the length of the moving path.

[0114] If processing alignment mark combinations, determine the Manhattan distance between every two alignment marks as the length of the moving path.

[0115] In a possible implementation manner, the above-mentioned target alignment mark determination module 515 is specifically configured to:

[0116] Search downward in the alignment marks for an alignment mark with a different mark type from the previous alignment mark according to the determined alignment order;

[0117] Taking the position between the alignment mark with a mark type different from that of the previous alignment mark and the previous alignment mark as a splitting point, pairing the alignment marks before the splitting point in pairs according to the determined alignment order to obtain the initial pairing quantity;

[0118] Determining whether the initial pairing quantity is less than a predetermined pairing quantity;

[0119] If the initial pairing quantity is less than the predetermined pairing quantity, then pairing the alignment marks after the splitting point in groups of four according to the determined alignment order to obtain the second pairing quantity;

[0120] Determining whether the sum of the initial pairing quantity and the second pairing quantity is equal to the predetermined pairing quantity;

[0121] If the sum of the initial pairing quantity and the second pairing quantity is equal to the predetermined pairing quantity, then taking the paired alignment marks before the splitting point and the paired alignment marks after the splitting point as the target alignment marks of the target wafer.

[0122] The determining device for the alignment marks of the wafer provided by the embodiments of the present application can select the alignment marks that make the wafer stage move a smaller distance through the mark type, mark quality, and nominal coordinates of the alignment marks of the wafer, thereby improving the efficiency of manufacturing chips and reducing the cost required for manufacturing chips.

[0123] See Figure 6 as shown Figure 6 is a schematic diagram of an electronic device provided by an embodiment of the present application. The electronic device 600 includes: a processor 610, a memory 620, and a bus 630. The memory 620 stores machine-readable instructions executable by the processor 610. When the electronic device runs, the processor 610 communicates with the memory 620 through the bus 630, and the processor 610 executes the machine-readable instructions to perform the steps of the method for determining the alignment marks of the wafer as described above.

[0124] Specifically, the above-mentioned memory 620 and processor 610 can be general memories and processors, which are not specifically limited here. When the processor 610 runs the computer program stored in the memory 620, it can execute the method for determining the alignment marks of the wafer as described above.

[0125] Corresponding to the above method for determining the alignment marks of the wafer, an embodiment of the present application also provides a computer-readable storage medium. A computer program is stored on the computer-readable storage medium, and when the computer program is run by a processor, it executes the steps of the method for determining the alignment marks of the wafer as described above.

[0126] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems and devices described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein. In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of the modules is only a logical functional division, and there can be other division methods in actual implementation. For another example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the couplings or direct couplings or communication connections shown or discussed with each other can be through some communication interfaces, and the indirect couplings or communication connections of the devices or modules can be in electrical, mechanical, or other forms.

[0127] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they can be located in one place or distributed to multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0128] In addition, in each embodiment of the present application, the functional modules can be integrated into one processing module, or each module can exist physically alone, or two or more modules can be integrated into one module.

[0129] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium executable by a processor. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0130] Finally, it should be noted that the above-described embodiments are only specific implementation manners of the present application, used to illustrate the technical solutions of the present application, rather than limiting it. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: Any person skilled in the art within the technical scope disclosed by the present application can still modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method for determining alignment marks on a wafer, characterized in that, the wafer includes a plurality of exposure blocks, each exposure block includes at least one alignment mark unit, and each alignment mark unit is provided with an alignment mark; the alignment mark includes at least one X mark parallel to the horizontal X axis and / or at least one Y mark parallel to the vertical Y axis; the determination method includes: Obtaining the mark type and mark quality of the alignment marks provided on each alignment mark unit on the target wafer; the mark type includes XY type, X type, and Y type; the XY type is the type in which the alignment mark includes at least one X mark and at least one Y mark at the same time; the X type is the type in which the alignment mark only includes at least one X mark; the Y type is the type in which the alignment mark only includes at least one Y mark; the mark quality is used to evaluate the quality of the X mark and / or Y mark on each alignment mark; the mark quality includes A quality and B quality; Combining according to the obtained mark type and mark quality of each alignment mark to obtain the category identifier of each alignment mark; the category identifier includes any one of the following items: the mark type is XY type and the mark quality is A, the mark type is XY type and the mark quality is B, the mark type is X type and the mark quality is A, the mark type is X type and the mark quality is B, the mark type is Y type and the mark quality is A, the mark type is Y type and the mark quality is B; Combining one alignment mark of X type and one alignment mark of Y type on each exposure block to obtain an alignment mark combination on each exposure block; and combining the category identifiers of each alignment mark in the alignment mark combination on each exposure block to obtain the category combination identifier of each alignment mark combination; the category combination identifier includes any one of the following items: the mark type is X type and the mark quality is A and the mark type is Y type and the mark quality is A, the mark type is X type and the mark quality is A and the mark type is Y type and the mark quality is B, the mark type is X type and the mark quality is B and the mark type is Y type and the mark quality is A, the mark type is X type and the mark quality is B and the mark type is Y type and the mark quality is B; Taking the shortest movement path of the moving stage as the goal, determining the alignment order of the alignment marks aligned by the moving stage under each category identifier or each category combination identifier; According to the determined alignment order, pairing the alignment marks according to the pre-determined number of pairs to obtain the target alignment marks of the target wafer.

2. The determination method according to claim 1, characterized in that, the determination method further includes: Determining the coordinate deviation between the nominal coordinate and the actual coordinate of each target alignment mark; Determining the sum of the coordinate deviations of all target alignment marks, and determining the alignment deviation of the target wafer based on the sum of the coordinate deviations; the alignment deviation is used for wafer alignment.

3. The determination method according to claim 1, characterized in that, the step of taking the shortest movement path of the moving stage as the goal and determining the order of the alignment marks aligned by the moving stage under each category identifier or category combination identifier includes: In the order of first processing the alignment marks and then processing the combination of alignment marks, when determining the shortest moving path of the stage for aligning all alignment marks for each alignment mark respectively, determine the alignment order of all alignment marks, and when determining the shortest path of the stage for aligning all combinations of alignment marks for the combination of alignment marks, determine the alignment order of all combinations of alignment marks.

4. The determination method according to claim 3, wherein, when determining the shortest path of the stage for aligning all alignment marks for each alignment mark respectively, the alignment order of all alignment marks includes: According to the determined order of the category identifiers, for the alignment marks under each category identifier, when determining the shortest moving path of the stage for aligning all alignment marks under the category identifier, determine the order of the alignment marks under the category identifier; when determining the shortest path of the stage for aligning all combinations of alignment marks for the combination of alignment marks, the alignment order of all combinations of alignment marks includes: According to the determined order of the category combination identifiers, for the alignment marks under each category combination identifier, when determining the shortest path of the stage for aligning all alignment marks under the category combination identifier, determine the order of the combination of alignment marks under the category combination identifier; wherein, when the mark type is XY type and the mark quality is A, if the number of alignment marks under the category identifier is odd, use the alignment mark with the shortest distance from the last alignment mark in the category identifier of XY type and mark quality A among the alignment marks of XY type and mark quality B as the first alignment mark of XY type and mark quality B to be aligned by the stage; when the mark type is XY type and the mark quality is B, if the number of alignment marks under the category identifier is odd, use the penultimate alignment mark under the category identifier as the last alignment mark of XY type and mark quality B to be aligned by the stage, and use the alignment mark with the shortest distance from the last alignment mark in the category identifier of XY type and mark quality B among the alignment marks of X type and mark quality A or Y type and mark quality A as the first alignment mark of X type and mark quality A or the first alignment mark of Y type and mark quality A to be aligned by the stage.

5. The determination method according to claim 4, wherein, when according to the determined order of the category identifiers, for the alignment marks under each category identifier, determining the order of the alignment marks under the category identifier when determining the shortest path of the stage for aligning all alignment marks under the category identifier, includes: According to the determined order of the category identifiers, for the alignment marks under each category identifier, determine the first mark distance between every two alignment marks according to the nominal coordinates of each alignment mark; Use the alignment marks with the first mark distance greater than the preset threshold as the expected alignment mark pairs, and starting from the position of the workpiece stage, determine the second mark distance from the position of the workpiece stage to the alignment mark closest to the position of the workpiece stage in each expected alignment mark pair; where the closest distance does not include a distance of zero; Take the desired alignment mark pair corresponding to the minimum sum value of the second mark distance and the first mark distance as the target alignment mark pair; Sort the order of the alignment marks in the target alignment mark pair according to the path of the moving stage movement to determine the alignment order of the alignment marks under this category identifier.

6. According to the determination method described in claim 3, characterized in that, The method for determining the length of the moving path includes: If processing alignment marks, determine the Euclidean distance between every two alignment marks as the length of the moving path; If processing alignment mark combinations, determine the Manhattan distance between every two alignment marks as the length of the moving path.

7. According to the determination method described in claim 1, characterized in that, Pairing the alignment marks according to the determined alignment order and the pre-determined pairing number to obtain the target alignment marks of the target wafer, including: According to the determined alignment order, search downward in the alignment marks for an alignment mark with a different mark type from the previous alignment mark; Take the position between the alignment mark with a different mark type from the previous alignment mark and the previous alignment mark as the split point, and pair the alignment marks before the split point in pairs according to the determined alignment order to obtain the initial pairing number; Determine whether the initial pairing number is less than the pre-determined pairing number; If the initial pairing number is less than the pre-determined pairing number, then pair the alignment marks after the split point in groups of four according to the determined alignment order to obtain the second pairing number; Determine whether the sum of the initial pairing number and the second pairing number is equal to the pre-determined pairing number; If the sum of the initial pairing number and the second pairing number is equal to the pre-determined pairing number, then take the alignment marks paired before the split point and the alignment marks paired after the split point as the target alignment marks of the target wafer.

8. An apparatus for determining alignment marks of a wafer, characterized in that, The determining apparatus includes: An acquisition module that acquires the mark type and mark quality of the alignment marks set on each alignment mark unit of the target wafer; the mark type includes XY type, X type, and Y type; the XY type is a type in which the alignment mark includes at least one X mark and at least one Y mark at the same time; the X type is a type in which the alignment mark only includes at least one X mark; the Y type is a type in which the alignment mark only includes at least one Y mark; the mark quality is used to evaluate the quality of the X mark and / or Y mark on each alignment mark; the mark quality includes A quality and B quality; A category identifier determination module that combines according to the mark type and mark quality of each acquired alignment mark to obtain the category identifier of each alignment mark; the category identifier includes any one of the following items: the mark type is XY type and the mark quality is A, the mark type is XY type and the mark quality is B, the mark type is X type and the mark quality is A, the mark type is X type and the mark quality is B, the mark type is Y type and the mark quality is A, the mark type is Y type and the mark quality is B; Category combination identification module, which combines an alignment mark of type X and an alignment mark of type Y on each exposure block to obtain an alignment mark combination on each exposure block; and combines the category identifications of each alignment mark in the alignment mark combination on each exposure block to obtain the category combination identification of each alignment mark combination; the category combination identification includes any one of the following items: type X mark with mark quality A and type Y mark with mark quality A, type X mark with mark quality A and type Y mark with mark quality B, type X mark with mark quality B and type Y mark with mark quality A, type X mark with mark quality B and type Y mark with mark quality B; Alignment order determination module, aiming at the shortest moving path of the moving stage, determines the alignment order of the alignment marks aligned by the moving stage under each category identification or each category combination identification; Target alignment mark determination module, according to the determined alignment order and the pre-determined pairing quantity, pairs the alignment marks to obtain the target alignment marks of the target wafer.

9. An electronic device, characterized in that, it includes: a processor, a memory and a bus, the memory stores machine-readable instructions executable by the processor, when the electronic device runs, the processor communicates with the memory through the bus, and when the machine-readable instructions are run by the processor, they execute the steps of the method for determining the alignment marks of the wafer as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, a computer program is stored on the computer-readable storage medium, and when the computer program is run by a processor, it executes the steps of the method for determining the alignment marks of the wafer as described in any one of claims 1 to 7.

Images