A method and electronic device for detecting crossover defects of double pattern mask optimization results

Abstract

The present invention relates to the technical field of integrated circuit manufacturing, and in particular to a method and electronic device for detecting bridging defects of double pattern mask optimization results, comprising the following steps: S1, providing a mask layout, the mask layout comprising a first layer of mask patterns and a second layer of mask patterns; S2, obtaining a first layer of line segments and a second layer of line segments, and placing detection points on the first layer of line segments; S3, setting a pairing rule, forming edge pairing and angle pairing; and S4, setting a first search range and a second search range, searching a first exposure pattern and / or a second exposure pattern, calculating a bridging distance based on the search results, and setting the search range of the exposure pattern according to different pairing types, so that the calculated bridging distance can accurately characterize the bridging defects of the first layer of mask patterns and the second layer of mask patterns, so as to better improve the yield of photolithography manufacturing.

Description

[Technical field]

[0001] The present invention relates to the technical field of integrated circuit manufacturing, and in particular to a method and electronic equipment for detecting crossover defects of double pattern mask optimization results. [Background technology]

[0002] As the integration of circuits continues to increase, the feature size of lithography graphics decreases, and the requirements for lithography resolution and lithography processes are becoming increasingly higher. Based on the current 1.35NA 193nm immersion lithography machine, for the requirements of logic technology nodes below 28nm, it is necessary to rely on double or multiple lithography technology to achieve the contraction of technology nodes. Double or multiple lithography technology is also developed in this context. At present, double exposure technology has been widely used in 22nm, 20nm, 16nm and 14nm technology nodes. Triple or multiple will also be used in 10nm technology nodes. Double or multiple lithography technology is suitable for lithography of any wavelength including EUV. For technology nodes of 7nm and below, EUV also needs to rely on double or multiple EUV lithography to meet resolution requirements.

[0003] There are two main ways to implement double pattern technology: one is exposure-etching-exposure-etching (LELE), which uses two masks to transfer the pattern to the same hard mask by exposure and etching respectively, and finally transfers the hard mask pattern to the substrate by etching; the other is self-aligned double exposure technology (SADP), which uses a mask to complete the exposure of the core pattern in one photolithography, and then uses non-photolithography processes (thin film deposition, etching, etc.) to spatially multiply the photolithography pattern, and finally uses one photolithography and etching to remove the redundant pattern. In view of the process requirements of SADP, it is suitable for regular and dense line patterns, such as storage cells, while two-dimensional patterns can only use LELE technology.

[0004] After the double pattern mask is optimized, the predicted exposure pattern is obtained through simulation calculation, and it is also necessary to verify whether it meets the requirements of the process window. The bridging defect is the distance between adjacent exposure patterns. This distance is defined as the local minimum of the distance between exposure patterns. We believe that it is the position with the greatest risk. The bridging defect between double patterns will cause the adjacent patterns before splitting to overlap. When reflected in the actual circuit, it may cause a short circuit in the circuit and bring irreparable losses. Only detecting the predicted exposure pattern defects of a single layer cannot capture the bridging defects of the adjacent two layers of patterns after splitting. There is a greater risk. Therefore, it is very necessary to detect the bridging defects of the mask optimization results of the double pattern. Bad points can be found in time and solved by further adjusting the results of mask optimization or adding auxiliary patterns to meet the process window requirements and greatly improve the yield of lithography manufacturing. [Summary of the invention]

[0005] In order to overcome the current technical problem of low accuracy in detecting bridging defects of double pattern mask optimization results, the present invention provides a method and electronic equipment for detecting bridging defects of double pattern mask optimization results.

[0006] In order to solve the above technical problems, the present invention provides a technical solution: a method for detecting crossover defects of double pattern mask optimization results, comprising the following steps: S1, providing a mask layout, wherein the mask layout comprises at least one first-layer mask pattern and at least one second-layer mask pattern; S2, breaking the edges of the at least one first-layer mask pattern and the at least one second-layer mask pattern to obtain a plurality of first-layer line segments about the first-layer mask pattern and a plurality of second-layer line segments about the second-layer mask pattern, and placing a detection point on each of the first-layer line segments or each of the second-layer line segments; S3, setting a pairing rule for the first-layer line segments and the second-layer line segments; Then, according to the placed detection points, based on the pairing rules, pairing types for the first layer line segments and the second layer line segments are formed, and the pairing types include edge pairing and angle pairing; and S4, define the predicted exposure pattern for the multiple first layer line segments as the first exposure pattern, and the predicted exposure pattern for the multiple second layer line segments as the second exposure pattern, set a first search range for edge pairing and a second search range for angle pairing, search the first exposure pattern and / or the second exposure pattern according to the first search range and the second search range, and calculate the bridge distance between the first exposure pattern and the second exposure pattern based on the search results.

[0007] Preferably, the method for detecting bridging defects of double pattern mask optimization results further comprises the following steps: S5, setting a bridging threshold range, outputting a bridging distance within the bridging threshold range and defining it as a bridging defect.

[0008] Preferably, in the above step S2, a detection point is placed at the midpoint of each first layer line segment or a detection point is placed at the midpoint of each second layer line segment.

[0009] Preferably, the edge pairing includes edge-to-edge pairing, and the angle pairing includes edge-to-diagonal pairing, corner-to-edge pairing and corner-to-diagonal pairing.

[0010] Preferably, the pairing rules include edge pairing rules and angle pairing rules. Edge-to-edge pairing is generated based on the edge pairing rules, and edge-to-diagonal pairing, angle-to-edge pairing and angle-to-diagonal pairing are generated based on the angle pairing rules: the edge pairing rules are as follows: the second-layer line segments are parallel to the first-layer line segments, and there is an overlapping part between the first-layer line segments and the second-layer line segments, and the first-layer line segments are adjacent to the second-layer line segments; the angle pairing rules include: angle-to-diagonal pairing rules: define the filling area within the contour of all first-layer mask patterns and second-layer mask patterns as the right side relative to the first-layer line segments or the second-layer line segments, define the angle area where the detection points are placed as the angle to be matched, and define the first side and the second side according to the direction of the two line segments in the angle area; the angle paired with the angle to be matched is defined as the pairing angle; the vertex of the angle to be matched is on the left side of the two sides of the pairing angle at the same time, the vertex of the pairing angle is on the left side of the two sides of the angle to be matched at the same time, and the first side of the angle to be matched and the first side of the pairing angle are in opposite directions, and the The second side of the matching angle and the second side of the paired angle are in opposite directions; or the vertex of the angle to be matched is on the left side of both sides of the paired angle, the vertex of the paired angle is on the left side of both sides of the angle to be matched, and the second side of the angle to be matched is in opposite directions to the first side of the paired angle, and the first side of the angle to be matched is in opposite directions to the second side of the paired angle. The opposite direction is defined as the angle difference being greater than 90 degrees and less than or equal to 180 degrees. Angle-to-side pairing rule: the detection point is placed on side A, and the angle matching side A is ∠A, ∠ The vertex of A is on the left side of side A; the distance from the starting point of ∠A to side A is not equal to the distance from the vertex of ∠A to side A, and the distance from the end point of ∠A to side A is not equal to the distance from the vertex to side A; side-to-angle pairing rule: the detection point is placed on ∠A, the angle matching ∠A is side A, the vertex of ∠A is on the left side of side A, and when ∠A is an internal angle, the vertex of the angle is on the left side of side A; the distance from the starting point of ∠A to side A is not equal to the distance from the vertex of ∠A to side A, and the distance from the end point of ∠A to side A is not equal to the distance from the vertex to side A.

[0011] Preferably, in the above step S4, the following steps are specifically included: S41, setting search rules, and searching the first exposure pattern and the second exposure pattern according to the first search range and the second search range based on the search rules; S42, judging whether the first exposure pattern and / or the second exposure pattern are found according to the search results, and if not, executing the following steps: S43, assigning the bridge distance to 0; if yes, executing the following steps: S44, matching the first exposure pattern and the second exposure pattern; and S45, setting a bridge distance calculation method, and calculating the bridge distance according to the calculation method.

[0012] Preferably, the search rules are as follows: when the pairing type is edge pairing, the line segment where the detection point is placed is AB, and points adjacent to the projection points of the detection points on the exposure figure in the same direction as AB are searched along the perpendicular direction of the line segment AB, and the point with the shortest vertical distance to the line segment AB is the target point; when the pairing type is angle pairing, the angle where the detection point is placed is ∠ACB, C is the vertex angle, the detection point is placed on the line segment AC, and points adjacent to the projection points of points C, A and B on the exposure figure in the same direction as the AB line are searched along the bisector of ∠ACB, and the point with the shortest vertical distance to the AB line is the target point.

[0013] Preferably, the search rule is as follows: in the above step S41, the first search range corresponds to the distance perpendicular to the line segment AB, in the above step S42, if the target point is not found in the first search range, it is considered that the first exposure pattern or the second exposure pattern is lost; in step S44, the target point is searched forward and backward respectively until the point on the figure cannot be vertically projected to the position of the extension of the line segment AB by a length, and the first exposure pattern or the second exposure pattern matching the line segment AB is obtained; in the above step S41, the second search range corresponds to the distance from the vertex C along the bisector of ∠ACB, in the above step S42, if the target point is not found in the second search range for point A, point B and point C, it is considered that the first exposure pattern or the second exposure pattern is lost; in step S44, the target point is searched forward and backward respectively until the point on the figure cannot be projected onto the line connecting AB along the angle bisector of ∠ACB, and the first exposure pattern or the second exposure pattern matching ∠ACB is obtained.

[0014] Preferably, in the above step S45, the calculation method is as follows: if the first exposure pattern and the second exposure pattern overlap, the bridge distance is assigned a value of 0; otherwise, the bridge distance is calculated according to the following method: multiple first calculation points are placed on the first exposure pattern, and second calculation points corresponding to the first calculation points are placed on the second exposure pattern, a first calculation point or a second calculation point is selected as the current point, and the first distance between the second calculation points corresponding to the current first calculation point is calculated, and the second distance and the third distance between a first calculation point on both sides adjacent to the current first calculation point and the corresponding second calculation point are calculated, and the moving direction of the current point is determined according to the relationship between the second distance, the third distance and the first distance, and the current point and the current bridge distance are updated.

[0015] In order to solve the above technical problems, the present invention also provides an electronic device, which includes one or more processors; a storage device for storing one or more programs, when the one or more programs are executed by the one or more processors, the one or more processors implement the bridging defect detection method of the double graphic mask optimization result as described above.

[0016] Compared with the prior art, the method and electronic device for detecting bridging defects of double pattern mask optimization results provided by the present invention have the following beneficial effects, including the following steps: S1, providing a mask layout, wherein the mask layout includes at least one first-layer mask pattern and at least one second-layer mask pattern; S2, interrupting the edges of the at least one first-layer mask pattern and the at least one second-layer mask pattern to obtain a plurality of first-layer line segments about the first-layer mask pattern and a plurality of second-layer line segments about the second-layer mask pattern, and placing detection points on each of the first-layer line segments or each of the second-layer line segments; S3, setting a pairing rule for the first-layer line segments and the second-layer line segments, and forming a pairing type for the first-layer line segments and the second-layer line segments based on the placed detection points and the pairing rule, wherein the pairing type includes edge pairing and angle pairing; and S4 , define the predicted exposure pattern about the multiple first-layer line segments as the first exposure pattern, and the predicted exposure pattern about the multiple second-layer line segments as the second exposure pattern, set a first search range about edge pairing, and a second search range about angle pairing, respectively, search the first exposure pattern and / or the second exposure pattern according to the first search range and the second search range, and calculate the bridging distance between the first exposure pattern and the second exposure pattern based on the search results. Since the mask pattern includes an edge area and an angle area, which have different influences on the exposure pattern, the double mask pattern is divided into different pairing types, and the search range of the exposure pattern is set according to the different pairing types, so that the calculated bridging distance can accurately characterize the bridging defects of the first layer mask pattern and the second layer mask pattern, so as to better improve the yield of lithography manufacturing.

[0017] In the above step S2, placing a detection point at the midpoint of each first-layer line segment or placing a detection point at the midpoint of each second-layer line segment can regularize the placement of the detection points and form a placement rule.

[0018] The electronic device provided by the present invention has the same beneficial effects as the method.

Brief Description of the Drawings

[0019] Figure 1 It is a flow chart of a method for detecting a bridging defect of a double pattern mask optimization result provided by a first embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of a mask layout in a method for detecting crossover defects of a double pattern mask optimization result provided by a first embodiment of the present invention;

[0021] Figure 3 It is a schematic diagram of the pairing type of edge-to-edge pairing in the bridging defect detection method of the double pattern mask optimization result provided by the first embodiment of the present invention;

[0022] Figure 4 It is a schematic diagram of a pairing type of corner-to-corner pairing in a method for detecting a bridging defect of a double pattern mask optimization result provided by a first embodiment of the present invention;

[0023] Figure 4A , Figure 4B and Figure 4C It is a schematic diagram of the directions of the first layer line segments and the second layer line segments in the bridging defect detection method of the double pattern mask optimization result provided by the first embodiment of the present invention when the corner area is an inner corner;

[0024] Figure 5 It is a schematic diagram of the pairing type of the bridging defect detection method of the double pattern mask optimization result provided by the first embodiment of the present invention as the side-to-diagonal pairing;

[0025] Figure 6 It is a schematic diagram of the pairing type of corner-to-edge pairing in the bridging defect detection method of the double pattern mask optimization result provided by the first embodiment of the present invention;

[0026] Figure 7 It is a schematic diagram of category identification of detection points after forming a pairing type on a mask layout in a method for detecting a bridging defect of a double pattern mask optimization result provided by the first embodiment of the present invention;

[0027] Figure 8 is a detailed flow chart of step S4 in the method for detecting bridging defects of double pattern mask optimization results provided by the first embodiment of the present invention;

[0028] Fig. 9 It is a schematic diagram of matching predicted exposure patterns when edge pairing in a bridging defect detection method of a double pattern mask optimization result provided by the first embodiment of the present invention;

[0029] Fig.10 It is a schematic diagram of matching predicted exposure patterns when corner types are paired in a bridging defect detection method of a double pattern mask optimization result provided by the first embodiment of the present invention;

[0030] Fig.11 It is a schematic diagram of the settings and association of the first calculation point and the second calculation point when calculating the bridging distance when the edge type is paired in the bridging defect detection method of the double pattern mask optimization result provided by the first embodiment of the present invention;

[0031] Fig.12 It is another schematic diagram of the setting and association of the first calculation point and the second calculation point when calculating the bridging distance when the edge type is paired in the bridging defect detection method of the double pattern mask optimization result provided by the first embodiment of the present invention;

[0032] Fig.13is a flow chart of a method for detecting a bridging defect of a double pattern mask optimization result provided in a variation of the first embodiment of the present invention;

[0033] Fig.14 is a schematic diagram of a module of an electronic device provided in a second embodiment of the present invention;

[0034] Fig.15 It is a schematic diagram of the structure of a computer system suitable for implementing a server of an embodiment of the present invention. [Specific implementation method]

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] See also Figure 1 The first embodiment of the present invention provides a method for detecting crossover defects of double pattern mask optimization results, comprising the following steps:

[0037] S1. Providing a mask layout, wherein the mask layout includes at least one first-layer mask pattern and at least one second-layer mask pattern;

[0038] S2, breaking the edges of the at least one first-layer mask pattern and the at least one second-layer mask pattern to obtain a plurality of first-layer line segments about the first-layer mask pattern and a plurality of second-layer line segments about the second-layer mask pattern, and placing a detection point on each of the first-layer line segments or each of the second-layer line segments;

[0039] S3, setting a pairing rule for the first layer line segments and the second layer line segments, and forming a pairing type for the first layer line segments and the second layer line segments based on the pairing rule according to the placed detection points, wherein the pairing type includes edge pairing and angle pairing; and

[0040] S4. Define the predicted exposure pattern regarding the multiple first-layer line segments as the first exposure pattern, and the predicted exposure pattern regarding the multiple second-layer line segments as the second exposure pattern, set a first search range regarding edge pairing, and a second search range regarding angle pairing, respectively, search the first exposure pattern and / or the second exposure pattern according to the first search range and the second search range, and calculate the bridge distance between the first exposure pattern and the second exposure pattern based on the search results.

[0041] See also Figure 2In the above step S1, in some specific implementations, the first layer mask pattern and the second layer mask pattern on the mask pattern are in the shape of long rectangular strips. Of course, other shapes are also possible, such as trapezoids, irregular polygons, regular polygons, or other shapes with angles of 45°, 135° or 90°. Figure 2 In the figure, the number 10 corresponds to the first layer of mask patterns, corresponding to the area where the fill line in the figure is tilted to the left, and the number 20 corresponds to the second layer of mask patterns, corresponding to the area where the fill line in the figure is tilted to the right.

[0042] Please continue reading Figure 2 In the above step S2, the edges of at least one first-layer mask pattern and at least one second-layer mask pattern are interrupted to obtain multiple first-layer line segments about the first-layer mask pattern and multiple second-layer line segments about the second-layer mask pattern, and detection points are placed on each of the first-layer line segments or each of the second-layer line segments. In the process of mask layout optimization, in order to obtain better optimization results, it is usually necessary to first interrupt the edges of the long strip-shaped first-layer mask pattern and the second-layer mask pattern to obtain multiple first-layer line segments and multiple second-layer line segments with relatively short line segment lengths. The specific lengths of the first-layer line segments and the second-layer line segments can be determined according to actual optimization requirements or set according to user needs. Figure 3 The point O in the figure corresponds to the point where the line segment is interrupted, which corresponds to the point in the shape of a square in the figure, and is only indicated in the marked part of the figure.

[0043] When detecting the bridging defect formed by the first layer mask pattern and the second layer mask pattern, the detection point can be placed on the first layer line segment or on the second layer line segment.

[0044] Please continue reading Figure 2 , all the M points in the figure are placed detection points, corresponding to the points in black circles in the figure, and only the marked parts in the figure are illustrated. In the above step S2, in some specific implementations, the detection point is placed at the midpoint of each first-layer line segment or at the midpoint of each second-layer line segment. In the present invention, the detection point is placed at the midpoint of the first-layer line segment for specific description.

[0045] In the above step S3, a pairing rule for the first layer line segments and the second layer line segments is set, and a pairing type for the first layer line segments and the second layer line segments is formed based on the pairing rule according to the placed detection points, and the pairing type includes edge pairing and angle pairing. The edge pairing includes edge-to-edge pairing, and the angle pairing includes edge-to-diagonal pairing, angle-to-edge pairing, and angle-to-diagonal pairing.

[0046] In the actual process of mask pattern imaging, there is a big difference between the imaging corresponding to the edge area and the imaging corresponding to the corner area. Therefore, there is a big difference in the calculation method of the bridging defects between the two. In this step, setting the pairing rules to divide the pairing types of the first layer line segments and the second layer line segments can greatly improve the calculation accuracy of the bridging defects, thereby improving the accuracy of the optimization.

[0047] In some specific implementations, the pairing rules include edge pairing rules and angle pairing rules. The edge pairing rules are used to generate edge-to-edge pairings, and the angle pairing rules are used to generate edge-to-diagonal pairings, angle-to-edge pairings, and angle-to-angle pairings.

[0048] The edge pairing rules are as follows:

[0049] See also Figure 3 , the side A where the detection point M is placed is the first layer line segment, and the corresponding side B and side C correspond to the second layer line segments. The second layer line segments are parallel to the first layer line segments, and there is an overlap between the first layer line segments and the second layer line segments, and the first layer line segments are adjacent to the second layer line segments.

[0050] In this rule, the second-layer line segment is parallel to the first-layer line segment, that is, the cross product of the two is 0. The first-layer line segment and the second-layer line segment are adjacent to each other, that is, there is no other line segment in the vertical direction between the two, that is, the vertical distance between the two is the closest. Figure 3 , edge A forms an edge-to-edge pair with edge B, and edge A forms an edge-to-edge pair with edge C.

[0051] In order to better obtain the pairing between the edges, the search distance between the first layer line segment and the second layer line segment is set, and the search distance is 150-300nm. Optionally, the search distance can also be: 160nm, 180nm, 200nm, 250nm, 280nm. In a specific embodiment of the present invention, a search distance of 200nm is selected for the search. The search distance is greater than the bridging defect threshold. That is, when the distance from the first layer line segment is outside the search distance, it is considered that the second layer line segment that is paired with the first layer line segment cannot be found, that is, it is determined that it is not an edge-to-edge pairing and there is no risk of bridging defects.

[0052] As a variation, when the first-layer line segment is a line segment at a corner of the mask pattern, it is still paired side by side. This can greatly improve the accuracy of detection. Of course, if the length of the first-layer line segment corresponding to the corner is too small, less than 10nm, the side-to-side pairing and corner-to-corner pairing will no longer be performed.

[0053] The angle pairing rules include the corner-to-corner pairing rule, the angle-to-side pairing rule, and the side-to-corner pairing rule.

[0054] The rules for corner-to-corner pairing are as follows:

[0055] See also Figure 4 , define the filling area within the outline of all the first-layer mask patterns and the second-layer mask patterns to be on the right side relative to the direction of the first-layer line segment or the second-layer line segment, such as Figure 2 The area with hatching is the filled area. Define the corner area where the detection points are placed as the corner to be matched, such as Figure 4 In ∠A, the first side and the second side are defined according to the directions of the two line segments of the angle area; the angle paired with the angle to be matched is defined as the pairing angle, such as ∠D in the figure. The rules are as follows: the vertex of the angle to be matched is on the left side of both sides of the pairing angle, the vertex of the pairing angle is on the left side of both sides of the angle to be matched, and the first side of the angle to be matched and the first side of the pairing angle are in opposite directions, and the second side of the angle to be matched and the second side of the pairing angle are in opposite directions; or the vertex of the angle to be matched is on the left side of both sides of the pairing angle, the vertex of the pairing angle is on the left side of both sides of the angle to be matched, and the second side of the angle to be matched and the first side of the pairing angle are in opposite directions, and the first side of the angle to be matched and the second side of the pairing angle are in opposite directions. In this rule, opposite directions are defined as an angle difference greater than 90 degrees and less than or equal to 180 degrees. Figure 4 As shown in , the first side is 01 and the second side is 02. In the figure, ∠D is paired with ∠A to satisfy the above rules, so ∠A is an angle-to-angle pairing.

[0056] See also Figure 4A , 4B and Figure 4C In order to improve the accuracy of detection, no detection points are placed between the inner angles of the first layer line segments and the second layer line segments. The second edge along the first edge is defined as the inner angle on the left side of the first edge, and the second edge on the right side of the first edge is the outer angle.

[0057] The rules for pairing opposite corners are as follows:

[0058] See also Figure 5 , the detection point is placed on edge A, the angle matching edge A is ∠A, the vertex of ∠A is on the left side of edge A; the distance from the starting point of ∠A to edge A is not equal to the distance from the vertex of ∠A to edge A, and the distance from the end point of ∠A to edge A is not equal to the distance from the vertex of ∠A to edge A, Figure 5 The middle side A is the first-level line segment, and ∠A is the second-level line segment.

[0059] The rules for pairing sides and corners are as follows:

[0060] See also Figure 6, the detection point is placed on ∠A, the angle matching ∠A is side A, the vertex of ∠A is on the left side of side A, and when ∠A is an internal angle, the vertex of the angle is on the left side of side A; the distance from the starting point of ∠A to side A is not equal to the distance from the vertex of ∠A to side A, and the distance from the end point of ∠A to side A is not equal to the distance from the vertex to side A. In the figure, ∠A is a first-layer line segment, and side A is a second-layer line segment. It can be seen that the side-to-angle pairing rule is the same as the angle-to-side pairing rule.

[0061] See also Figure 7 After pairing according to the above pairing rules, point M1 in the figure corresponds to the edge-to-edge pairing type, M2 corresponds to the corner-to-corner pairing type, and M3 corresponds to the edge-to-diagonal pairing type and the corner-to-edge pairing type.

[0062] See also Figure 8 , step S4 specifically includes the following steps:

[0063] S41, setting a search rule, and searching for a first exposure pattern and a second exposure pattern according to the first search range and the second search range based on the search rule;

[0064] S42: judging whether the first exposure pattern and / or the second exposure pattern is found according to the search result; if not, executing the following steps:

[0065] S43, assigning the bridge distance to 0;

[0066] If so, perform the following steps:

[0067] S44, matching the first exposure pattern with the second exposure pattern; and

[0068] S45, setting a calculation method for the spanning distance, and calculating the spanning distance according to the calculation method.

[0069] The search rules are as follows:

[0070] See also Fig. 9 When the pairing type is edge pairing, the line segment where the detection point is placed is AB. The first point adjacent to the projection point of the detection point on the exposure pattern in the same direction as AB is searched along the perpendicular direction of the line segment AB. The point with the shortest perpendicular distance to the line segment AB is the target point, which is point P.

[0071] See also Fig.10 When the pairing type is angle pairing, the angle where the detection point is placed is ∠ACB, C is the vertex, and the detection point is placed on the line segment AC. The first point adjacent to the projection point of point C on the exposure figure in the same direction as the AB line is found along the bisector of ∠ACB. The point with the shortest vertical distance to the AB line is the target point, which is point P.

[0072] The search rules are as follows:

[0073] In the above step S41, the first search range corresponds to the distance perpendicular to the line segment AB. In the above step S42, if the target point P is not found in the first search range, it is considered that the first exposure pattern or the second exposure pattern is lost. The value of the first search range is: 40-60nm, and the value of the first search range can also be: 45nm, 50nm, 55nm, 57nm, 59nm or 60nm. In the present invention, 60nm is selected as the first search range for searching.

[0074] In step S44, the target point is searched forward and backward respectively until the point on the pattern cannot be vertically projected to the position of the extension length of the line segment AB, and the first exposure pattern or the second exposure pattern matching the line segment AB is obtained. The extension length is AC and BD. Setting a certain extension distance can well avoid incomplete matching of the first exposure pattern and the second exposure pattern, and improve the accuracy of the cross-connection defect detection.

[0075] In the above step S41, the second search range corresponds to the distance from the vertex C along the bisector of ∠ACB. In the above step S42, if point C cannot find the target point within the second search range, the target points of point A and point B within the second search range are searched in the same way. If point A, point B and point C cannot find the target point P, it is considered that the first exposure pattern or the second exposure pattern is lost. The second search range is: 50-90nm. Optionally, the second search range can also be: 55nm, 60nm, 65nm, 75nm, 80nm or 85nm. In the present invention, 60nm is selected as the second search range for searching.

[0076] In step S44, the target point P is searched forward and backward respectively until the point on the graph cannot be projected onto the line AB along the angle bisector direction of ∠ACB, thereby obtaining a first exposure graph or a second exposure graph matching ∠ACB.

[0077] In the above step S45, the calculation method is as follows:

[0078] If the first exposure pattern and the second exposure pattern overlap, the bridge distance is assigned a value of 0; otherwise, the bridge distance is calculated according to the following method:

[0079] See also Fig.11, corresponding to the first layer of line segments and the second layer of line segments generated when the edge-to-edge pairing is performed. The left side corresponds to the first exposure pattern, and the right side corresponds to the second exposure pattern. A plurality of first calculation points are placed on the first exposure pattern (it can also be understood as describing the first exposure pattern with a plurality of disconnected first calculation points), and the first calculation points include points a0, a1, a2, and a3, etc. A second calculation point corresponding to the first calculation point is placed on the second exposure pattern (it can also be understood as describing the first exposure pattern with a plurality of disconnected second calculation points), and the second calculation point includes points b12, b13, and b14, etc.

[0080] A first calculation point or a second calculation point is selected as the current point, the first distance between the second calculation point corresponding to the current first calculation point is calculated, the second distance and the third distance between a first calculation point on both sides adjacent to the current first calculation point and the corresponding second calculation point are calculated, and the moving direction of the current point is determined according to the relationship between the second distance, the third distance and the first distance, and the current point and the current bridge distance are updated to find the minimum bridge distance corresponding to the first layer line segment or the second layer line segment, which is defined as a bridge defect.

[0081] Please combine Fig.11 Specifically, starting from the direction of the first exposure pattern for the first time, the first calculation point of the current point is a1, and the point of the second exposure pattern corresponding to the first calculation point a1 is the second calculation point b13. The rule of point movement is that if the distance of a2b12 is less than the distance of a0b14, the first calculation point of the first exposure pattern moves forward by one, i.e., a2. If a1b13 is greater than the current bridge distance, the calculation is skipped, and the current point of the first exposure pattern or the second exposure pattern is updated according to the movement rule; if a1b13 is less than the current bridge distance, a0b14 and a2b12 are calculated. If the distance of a1b13 is smaller than the distances of a0b14 and a2b12, the current bridge distance is updated to a1b13, and the current point of the first exposure pattern or the second exposure pattern is updated according to the movement rule.

[0082] See also Fig.12 For the second time, if we start from the direction of the second exposure pattern, the rule of point movement is that if the distance of a2b12 is less than the distance of a0b14, the second calculation point of the second exposure pattern moves backward by one, that is, b12, and the current point is updated according to the same movement rule as the current search direction and the first time. The above calculation process is executed accordingly, and the final bridge distance value is what we are looking for.

[0083] See also Fig.13 The method for detecting crossover defects of double pattern mask optimization results also includes the following steps:

[0084] S5. Set a bridging threshold range, output the bridging distance within the bridging threshold range and define it as a bridging defect.

[0085] In this step, the crossover threshold range of the edge-to-edge pairing type is set to 0-30nm, optionally, the crossover threshold range can also be: 10nm, 15nm, 20nm or 25nm; the crossover threshold range of the corner-to-corner pairing type is 0-60nm, and the crossover threshold range can also be 20nm, 30nm, 40nm or 50nm; the crossover threshold range of the edge-to-diagonal pairing type and the corner-to-edge pairing type is 0-35nm, and the crossover threshold range can also be 10nm, 15nm, 20nm or 25nm.

[0086] See also Fig.14 , a second embodiment of the present invention provides an electronic device 300, which includes one or more processors 301;

[0087] The storage device 302 is used to store one or more programs.

[0088] When the one or more programs are executed by the one or more processors 301, the one or more processors 301 implement the bridging defect detection method of the double pattern mask optimization result as provided in the first embodiment or its variant embodiments.

[0089] Reference below Fig.15 , which shows a schematic diagram of the structure of a computer system 800 of a terminal device / server suitable for implementing an embodiment of the present invention. Fig.15 The terminal device / server shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of the present application.

[0090] like Fig.15 As shown, the computer system 800 includes a central processing unit (CPU) 801, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 802 or a program loaded from a storage part 808 into a random access memory (RAM) 803. In the RAM 803, various programs and data required for the operation of the system 800 are also stored. The CPU 801, the ROM 802, and the RAM 803 are connected to each other via a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.

[0091] The following components are connected to the I / O interface 805: an input section 806 including a keyboard, a mouse, etc.; an output section 807 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 808 including a hard disk, etc.; and a communication section 809 including a network interface card such as a LAN card, a modem, etc. The communication section 809 performs communication processing via a network such as the Internet. A drive 810 is also connected to the I / O interface 805 as needed. A removable medium 811, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 810 as needed, so that a computer program read therefrom is installed into the storage section 808 as needed.

[0092] According to an embodiment of the present disclosure, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present disclosure includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 809, and / or installed from the removable medium 811. When the computer program is executed by the central processing unit (CPU) 801, the above functions defined in the method of the present invention are executed. It should be noted that the computer-readable medium described in the present invention can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection having one or more conductors, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0093] Computer program code for performing the operations of the present application may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages, such as Java, Smalltalk, C++, and conventional procedural programming languages, such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0094] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present invention. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0095] The computer-readable medium carries one or more programs. When the one or more programs are executed by the device, the device performs the following steps: S1, providing a mask layout, wherein the mask layout includes at least one first-layer mask pattern and at least one second-layer mask pattern; S2, breaking the edges of the at least one first-layer mask pattern and the at least one second-layer mask pattern to obtain a plurality of first-layer line segments about the first-layer mask pattern and a plurality of second-layer line segments about the second-layer mask pattern, and placing a detection point on each of the first-layer line segments or each of the second-layer line segments; S3, setting a pairing rule for the first-layer line segments and the second-layer line segments; Then, according to the placed detection points, based on the pairing rules, pairing types for the first layer line segments and the second layer line segments are formed, and the pairing types include edge pairing and angle pairing; and S4, define the predicted exposure pattern for the multiple first layer line segments as the first exposure pattern, and the predicted exposure pattern for the multiple second layer line segments as the second exposure pattern, set a first search range for edge pairing and a second search range for angle pairing, search the first exposure pattern and / or the second exposure pattern according to the first search range and the second search range, and calculate the bridge distance between the first exposure pattern and the second exposure pattern based on the search results.

[0096] Compared with the prior art, the method and electronic device for detecting bridging defects of double pattern mask optimization results provided by the present invention have the following beneficial effects, including the following steps: S1, providing a mask layout, wherein the mask layout includes at least one first-layer mask pattern and at least one second-layer mask pattern; S2, interrupting the edges of the at least one first-layer mask pattern and the at least one second-layer mask pattern to obtain a plurality of first-layer line segments about the first-layer mask pattern and a plurality of second-layer line segments about the second-layer mask pattern, and placing detection points on each of the first-layer line segments or each of the second-layer line segments; S3, setting a pairing rule for the first-layer line segments and the second-layer line segments, and forming a pairing type for the first-layer line segments and the second-layer line segments based on the placed detection points and the pairing rule, wherein the pairing type includes edge pairing and angle pairing; and S4 , define the predicted exposure pattern about the multiple first-layer line segments as the first exposure pattern, and the predicted exposure pattern about the multiple second-layer line segments as the second exposure pattern, set a first search range about edge pairing, and a second search range about angle pairing, respectively, search the first exposure pattern and / or the second exposure pattern according to the first search range and the second search range, and calculate the bridging distance between the first exposure pattern and the second exposure pattern based on the search results. Since the mask pattern includes an edge area and an angle area, which have different influences on the exposure pattern, the double mask pattern is divided into different pairing types, and the search range of the exposure pattern is set according to the different pairing types, so that the calculated bridging distance can accurately characterize the bridging defects of the first layer mask pattern and the second layer mask pattern, so as to better improve the yield of lithography manufacturing.

[0097] In the above step S2, placing a detection point at the midpoint of each first-layer line segment or placing a detection point at the midpoint of each second-layer line segment can regularize the placement of the detection points and form a placement rule.

[0098] The electronic device provided by the present invention has the same beneficial effects as the method.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting crossover defects of double pattern mask optimization results, characterized in that: The steps include: S1. Providing a mask layout, wherein the mask layout includes at least one first-layer mask pattern and at least one second-layer mask pattern; S2, breaking the edges of the at least one first-layer mask pattern and the at least one second-layer mask pattern to obtain a plurality of first-layer line segments about the first-layer mask pattern and a plurality of second-layer line segments about the second-layer mask pattern, and placing a detection point on each of the first-layer line segments or each of the second-layer line segments; S3, setting a pairing rule for the first layer line segments and the second layer line segments, and forming a pairing type for the first layer line segments and the second layer line segments based on the pairing rule according to the placed detection points, wherein the pairing type includes edge pairing and angle pairing; and S4. Define the predicted exposure pattern regarding the multiple first-layer line segments as the first exposure pattern, and the predicted exposure pattern regarding the multiple second-layer line segments as the second exposure pattern, set a first search range regarding edge pairing, and a second search range regarding angle pairing, respectively, search the first exposure pattern and / or the second exposure pattern according to the first search range and the second search range, and calculate the bridge distance between the first exposure pattern and the second exposure pattern based on the search results.

2. The method for detecting crossover defects of double pattern mask optimization results according to claim 1, characterized in that: The method for detecting crossover defects of double pattern mask optimization results also includes the following steps: S5. Set a bridging threshold range, output the bridging distance within the bridging threshold range and define it as a bridging defect.

3. The method for detecting crossover defects of double pattern mask optimization results according to claim 1, characterized in that: In the above step S2, a detection point is placed at the midpoint of each first layer line segment or a detection point is placed at the midpoint of each second layer line segment.

4. The method for detecting crossover defects of double pattern mask optimization results according to claim 1, characterized in that: The edge pairing includes edge-to-edge pairing, and the angle pairing includes edge-to-diagonal pairing, corner-to-edge pairing, and corner-to-diagonal pairing.

5. The method for detecting crossover defects of double pattern mask optimization results according to claim 4, characterized in that: The pairing rules include side pairing rules and angle pairing rules. The side-to-side pairing is generated based on the side pairing rules, and the side-to-diagonal pairing, angle-to-side pairing and angle-to-diagonal pairing are generated based on the angle pairing rules: The edge pairing rules are as follows: The second-layer line segments are parallel to the first-layer line segments, and there is an overlapping portion between the first-layer line segments and the second-layer line segments, and the first-layer line segments and the second-layer line segments are adjacent to each other; Corner pairing rules include: Corner-to-corner pairing rule: define the filling area within the outline of all first-layer mask patterns and second-layer mask patterns as the right side relative to the direction of the first-layer line segments or the second-layer line segments, define the angular area where the detection points are placed as the angle to be matched, and define the first side and the second side according to the direction of the two line segments in the angular area; the angle paired with the angle to be matched is defined as the matching angle; the vertex of the angle to be matched is on the left side of both sides of the matching angle, the vertex of the matching angle is on the left side of both sides of the matching angle, and the first side of the angle to be matched is in opposite directions to the first side of the matching angle, and the second side of the angle to be matched is in opposite directions to the second side of the matching angle; or the vertex of the angle to be matched is on the left side of both sides of the matching angle, the vertex of the matching angle is on the left side of both sides of the matching angle, and the second side of the angle to be matched is in opposite directions to the first side of the matching angle, and the first side of the angle to be matched is in opposite directions to the second side of the matching angle, and the opposite direction is defined as an angle difference greater than 90 degrees and less than or equal to 180 degrees; Angle-to-edge pairing rule: The detection point is placed on edge A, the angle matching edge A is ∠A, and the vertex of ∠A is on the left side of edge A; the distance from the starting point of ∠A to edge A is not equal to the distance from the vertex of ∠A to edge A, and the distance from the end point of ∠A to edge A is not equal to the distance from the vertex to edge A; Side-to-angle pairing rule: The detection point is placed on ∠A, the angle matching ∠A is side A, and the vertex of ∠A is on the left side of side A; the distance from the starting point of ∠A to side A is not equal to the distance from the vertex of ∠A to side A, and the distance from the end point of ∠A to side A is not equal to the distance from the vertex to side A.

6. The method for detecting crossover defects of double pattern mask optimization results according to claim 1, characterized in that: In the above step S4, the following steps are specifically included: S41, setting a search rule, and searching for a first exposure pattern and a second exposure pattern according to the first search range and the second search range based on the search rule; S42: judging whether the first exposure pattern and / or the second exposure pattern is found according to the search result; if not, executing the following steps: S43, assigning the bridge distance to 0; If so, perform the following steps: S44, matching the first exposure pattern with the second exposure pattern; and S45, setting a calculation method for the spanning distance, and calculating the spanning distance according to the calculation method.

7. The method for detecting crossover defects of double pattern mask optimization results according to claim 6, characterized in that: The search rules are as follows: When the pairing type is edge pairing, the line segment where the detection point is placed is AB. Search for a point on the exposure graph in the same direction as AB along the perpendicular direction of the line segment AB that is adjacent to the projection point of the detection point. The point with the shortest perpendicular distance to the line segment AB is the target point. When the pairing type is angular pairing, the angle where the detection point is placed is ∠ACB, C is the vertex angle, and the detection point is placed on the line segment AC. Search along the bisector of ∠ACB for points adjacent to the projection points of points C, A, and B on the exposure figure in the same direction as the AB line. The point with the shortest vertical distance to the AB line is the target point.

8. The method for detecting crossover defects of double pattern mask optimization results according to claim 7, characterized in that: The search rules are as follows: In the above step S41, the first search range corresponds to the distance perpendicular to the line segment AB. In the above step S42, if the target point is not found in the first search range, it is considered that the first exposure pattern or the second exposure pattern is lost. In step S44, the target point is searched forward and backward respectively until the point on the graph cannot be vertically projected to a position extending a length of the line segment AB, and a first exposure graph or a second exposure graph matching the line segment AB is obtained; In the above step S41, the second search range corresponds to the distance from the vertex C along the bisector of ∠ACB. In the above step S42, if the target point is not found in the second search range among point A, point B and point C, it is considered that the first exposure pattern or the second exposure pattern is lost. In step S44, the target point is searched forward and backward respectively until the point on the figure cannot be projected onto the line AB along the angle bisector direction of ∠ACB, and the first exposure figure or the second exposure figure matching ∠ACB is obtained.

9. The method for detecting crossover defects of double pattern mask optimization results according to claim 7, characterized in that: In the above step S45, the calculation method is as follows: If the first exposure pattern and the second exposure pattern overlap, the bridge distance is assigned a value of 0; otherwise, the bridge distance is calculated according to the following method: Place multiple first calculation points on the first exposure pattern, place second calculation points corresponding to the first calculation points on the second exposure pattern, select a first calculation point or a second calculation point as the current point, calculate the first distance between the second calculation points corresponding to the current first calculation point, calculate the second distance and the third distance between a first calculation point on both sides adjacent to the current first calculation point and the corresponding second calculation point, determine the moving direction of the current point according to the relationship between the second distance, the third distance and the first distance, and update the current point and the current jump distance.

10. An electronic device, characterized in that: It includes one or more processors; a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the method for detecting bridging defects of a double pattern mask optimization result according to any one of claims 1 to 9.

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