Optical proximity correction method and system, mask, apparatus, and storage medium

Abstract

An optical proximity correction method and system, a mask, a device and a storage medium, the optical proximity correction method comprising: providing a design pattern, the design pattern comprising a plurality of main patterns, the main patterns having right-angle corners; performing optical proximity effect correction processing on the main patterns to obtain a corrected pattern, the optical proximity effect correction processing comprising chamfering or rounding the right-angle corners. The stress of the target layer at the corner is reduced, which can improve the problem of stress concentration. When the target layer is covered by other film layers around, the stress of the target layer at the corner will affect the other film layers. Therefore, by reducing the stress of the target layer at the corner, the probability of cracks of the film layers covered around the target layer at the corner of the target layer is reduced, thereby facilitating to improve the chip reliability.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing, and more particularly to an optical proximity correction method and system, a photomask, an apparatus, and a storage medium. Background Technology

[0002] With the development trend of very large-scale integrated circuits (VLSI), the feature size of integrated circuits continues to shrink, and the requirements for integrated circuit packaging technology are also constantly increasing. Existing packaging technologies include ball grid array (BGA), chip scale package (CSP), wafer level package (WLP), 3D packaging, and system in package (SiP).

[0003] However, as chip sizes shrink and packaging processes become more diverse, stress concentration can easily occur at right-angle corners of metal lines. The film layer formed at these corners is susceptible to stress, leading to cracks within the film layer.

[0004] Cracks that appear inside the film layer will continue to worsen during subsequent high-temperature, high-pressure, and high-humidity environmental tests, leading to a decrease in chip reliability. Summary of the Invention

[0005] The problem solved by the embodiments of the present invention is to provide an optical proximity correction method and system, mask, device and storage medium to improve chip reliability.

[0006] To address the aforementioned problems, embodiments of the present invention provide an optical proximity correction method, comprising: providing a design graphic, the design graphic including multiple main graphics, the main graphics having right-angle corners; performing optical proximity effect correction processing on the main graphics to obtain a corrected graphic, the optical proximity effect correction processing including chamfering or rounding the right-angle corners.

[0007] Accordingly, this embodiment of the invention also provides an optical proximity correction system, comprising: a graphic providing module for providing a design graphic, the design graphic including a plurality of main graphics, the main graphics having right-angle corners; and a graphic correction module for performing optical proximity effect correction processing on the main graphics to obtain a corrected graphic, the optical proximity effect correction processing including chamfering or rounding the right-angle corners.

[0008] Accordingly, embodiments of the present invention also provide a photomask, including a pattern obtained using the optical proximity correction method provided in embodiments of the present invention.

[0009] Accordingly, embodiments of the present invention also provide an apparatus including at least one memory and at least one processor, wherein the memory stores one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the optical proximity correction method provided in embodiments of the present invention.

[0010] Accordingly, embodiments of the present invention also provide a storage medium storing one or more computer instructions, which are used to implement the optical proximity correction method provided in embodiments of the present invention.

[0011] Compared with the prior art, the technical solution of the embodiments of the present invention has the following advantages:

[0012] This invention provides a method for forming a mask pattern, providing a design pattern including multiple main patterns, each main pattern having a right-angle corner; performing optical proximity correction processing on the main patterns to obtain a corrected pattern, the optical proximity correction processing including chamfering or rounding the right-angle corners, by chamfering to change the right-angle corners to obtuse corners, or by rounding to change the right-angle corners to rounded corners, accordingly, after transferring the corrected pattern to the substrate to form a target layer, the corners of the target layer are obtuse or rounded, which reduces the stress at the corners of the target layer and can improve the stress concentration problem. When the target layer is covered by other film layers, the stress at the corners of the target layer will affect the other film layers. Therefore, by reducing the stress at the corners of the target layer, the probability of cracks appearing in the film layers covering the target layer at the corners of the target layer is reduced, thereby improving chip reliability. Attached Figure Description

[0013] Figure 1 It is a top view of a semiconductor structure;

[0014] Figure 2 This is a flowchart of an embodiment of the optical proximity correction method of the present invention;

[0015] Figure 3 yes Figure 2 A schematic diagram of step S1 of an embodiment;

[0016] Figure 4 yes Figure 2 A schematic diagram of an embodiment of step S2;

[0017] Figure 5 yes Figure 2 A flowchart of step S2 in one embodiment;

[0018] Figure 6 This is a schematic diagram of another embodiment of the optical proximity correction method of the present invention;

[0019] Figure 7 This is a functional block diagram of an embodiment of the optical proximity correction system of the present invention;

[0020] Figure 8 This is a hardware structure diagram of an embodiment of the device provided by the present invention. Detailed Implementation

[0021] The reliability of current chips needs improvement. This paper analyzes the reasons why the performance of a particular chip needs improvement, using a partial structural analysis of the chip.

[0022] Figure 1 It is a top view of a semiconductor structure.

[0023] refer to Figure 1 The semiconductor structure includes: a metal line 10, the metal line 10 having a concave corner, the concave corner being a right angle; and a passivation layer 11 covering the sidewall of the metal line 10.

[0024] Research has revealed that when the concave corner of the metal wire 10 is a right angle, stress concentration occurs at the corner, increasing the likelihood of cracks appearing in the passivation layer 11 covering the sidewall of the metal wire 10 at the corner (e.g., Figure 1 The probability (shown in the dashed circle in the middle) reduces the reliability of the chip.

[0025] To address this issue, a common approach is to perform multiple etching processes to alter the pattern at the corners of the metal line 10, thereby preventing stress concentration at these corners and reducing the probability of cracks. However, multiple etching processes increase the number of times a photomask is used, significantly raising process costs and hindering large-scale production.

[0026] In addition, another commonly used approach is to increase the thickness of the film layer formed at the corner of the metal line 10. By increasing the thickness of the film layer, the probability of cracks appearing inside the film layer at the corner of the metal line 10 can be reduced. However, increasing the thickness of the film layer will introduce other process problems, which poses a greater risk and is not conducive to large-scale production.

[0027] To address the aforementioned technical problem, embodiments of the present invention provide an optical proximity correction method, comprising: providing a design graphic, the design graphic including a plurality of main graphics, the main graphics having right-angle corners; performing optical proximity effect correction processing on the main graphics, the optical proximity effect correction processing including chamfering or rounding the right-angle corners.

[0028] In this embodiment of the invention, optical proximity effect correction processing is performed on the main pattern to obtain a corrected pattern. The optical proximity effect correction processing includes chamfering or rounding the right-angle corners. By chamfering, the right-angle corners are changed to obtuse corners, or by rounding, the right-angle corners are changed to rounded corners. Correspondingly, after the corrected pattern is transferred to the substrate to form a target layer, the corners of the target layer are obtuse or rounded, which reduces the stress at the corners of the target layer and improves the stress concentration problem. When other films cover the target layer, the stress at the corners of the target layer will affect the other films. Therefore, by reducing the stress at the corners of the target layer, the probability of cracks appearing at the corners of the target layer is reduced, thereby improving chip reliability.

[0029] refer to Figure 2 The flowchart illustrates an embodiment of the optical proximity correction method of the present invention. The optical proximity correction method includes the following basic steps:

[0030] Step S1: Provide a design graphic, which includes multiple main graphics, each main graphic having a right-angle corner;

[0031] Step S2: Perform optical proximity effect correction processing on the main graphic to obtain the corrected graphic. The optical proximity effect correction processing includes chamfering or rounding the right-angle corners.

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0033] Reference Figure 3 Step S1 is executed to provide a design graphic 100, which includes a plurality of main graphics 101, and the main graphics 101 have right-angle corners.

[0034] After optical proximity correction is performed on the design pattern 100, the obtained corrected pattern is used to make a mask, and then photolithography is performed on the mask to form the corresponding target pattern on the wafer.

[0035] Specifically, optical proximity correction is subsequently performed on the right-angle corners of the main graphic 101.

[0036] like Figure 3 (a) Figure 3 (b) and Figure 3 As shown in (c), in this embodiment, the plurality of main graphics 101 may have different shapes and layouts according to design requirements.

[0037] In this embodiment, the main pattern 101 is a metal line pattern. After the metal line pattern is transferred to the substrate to form a target pattern, the target pattern is a metal line. The metal line is used to electrically connect the interconnect structure in the semiconductor device to an external circuit.

[0038] It should be noted that the metal lines are divided into interlayer metal lines and top layer metal lines. The layer covering the interlayer metal lines is the dielectric layer, and the layer covering the top layer metal lines is the passivation layer. In this embodiment, the metal line corresponding to the metal line pattern is the top layer metal line, that is, the metal line pattern is the top layer metal line pattern.

[0039] In this embodiment, the main graphic 101 has a right-angle corner (such as...). Figure 3 (As shown in the dashed circle).

[0040] In this embodiment, the right-angle corner includes one or both of concave and convex corners. As an example, the right-angle corners to be optically proximity corrected are all concave corners.

[0041] In this embodiment, in the step of providing the design graphic 100, the main graphic 101 is formed by multiple sides, the right-angle corner is formed by the intersection of two adjacent perpendicular sides, the included angle between the two adjacent sides corresponding to the concave corner is 90°, and the included angle between the two adjacent sides corresponding to the convex corner is 270°.

[0042] Specifically, taking any right-angled corner of any main graphic 101 as an example, the right-angled corner is formed by the intersection of the first perpendicular side 160 and the second perpendicular side 161.

[0043] The perpendicular first side 160 and the second side 161 provide the basis for subsequent chamfering or rounding of the right-angle corner.

[0044] In this embodiment, since the shape and layout of the target graphic (e.g., metal wire) are inconsistent, there is a case in which the interval distance d between adjacent main graphics 101 is at its minimum value during the step of providing design graphic 100.

[0045] For example, Figure 3 (c) The spacing d between adjacent main graphics 101 shown is the minimum value among all spacing distances.

[0046] refer to Figure 4 Step S2 is executed to perform optical proximity effect correction processing on the main graphic 100 to obtain the corrected graphic. The optical proximity effect correction processing includes chamfering or rounding the right-angle corners.

[0047] By chamfering, right-angled corners are transformed into obtuse corners, or by rounding, right-angled corners are transformed into rounded corners. Correspondingly, after the corrected pattern is transferred to the substrate to form the target layer, the corners of the target layer are obtuse or rounded, which reduces the stress at the corners of the target layer and improves the stress concentration problem. When other films cover the target layer, the stress at the corners of the target layer will affect the other films. Therefore, by reducing the stress at the corners of the target layer, the probability of cracks appearing at the corners of the target layer is reduced, thereby improving chip reliability.

[0048] refer to Figure 5 The flowchart of an embodiment of step S2 is shown. The method for optical proximity effect correction processing of the main pattern includes the following basic steps.

[0049] Step S21: Determine the preset length of the right-angled side as the first preset length and the preset length of the hypotenuse as the second preset length;

[0050] Step S22: Compare the length of the first side with the first preset length, and the length of the second side with the first preset length;

[0051] Step S231: When the lengths of the first side 160 and the second side 161 are both greater than the first preset length, at the right-angle corner, the first side 160 of the first preset length is cut off as the first line segment, and the second side 161 of the first preset length is cut off as the second line segment; the first line segment and the second line segment are replaced with the third side, and the first line segment, the second line segment and the third side form a triangle;

[0052] Step S232: When the length of either the first side 160 or the second side 161 is less than or equal to the first preset length, according to the second preset length, at the right-angle corner, the first side 160 of a third preset length is cut off as the first line segment, and the second side 161 of a fourth preset length is cut off as the second line segment; the first line segment and the second line segment are replaced with the third side, the length of the third side is the second preset length, and the first line segment, the second line segment and the third side form a triangle.

[0053] Reference Figure 4 , Figure 4 yes Figure 2 A schematic diagram of an embodiment of step S2. This embodiment uses the chamfering treatment of the right-angle corner as an example for explanation.

[0054] like Figure 4As shown in (a), step S21 is executed to determine the preset length of the right-angled side as the first preset length H1 and the preset length of the hypotenuse as the second preset length H2.

[0055] The right-angled corner is then chamfered, transforming it into an obtuse corner. This is equivalent to adding a triangular corner element at the right-angled corner. Accordingly, the right-angled side is the right-angled side of the triangle, and the hypotenuse is the hypotenuse of the triangle.

[0056] It should be noted that after optical proximity effect correction processing is performed on the main graphic, the main graphic and the added corner supplementary graphic constitute a unified corrected graphic.

[0057] By first determining the first preset length H1 and the second preset length H2, it is possible to compare them with the lengths of the first side 160 and the second side 161 of the right-angle corner, thereby determining the specific method for chamfering the right-angle corner.

[0058] It should be noted that the ratio of the first preset length H1 to the length of the first side 160 should not be too large or too small. If the ratio is too small, it may lead to excessive stress at the corners of the subsequently formed target layer, failing to effectively improve stress concentration. When other films cover the target layer, this increases the probability of cracks appearing at the corners of the target layer. If the ratio is too large, it increases the probability of short circuits between different metal lines, thus affecting the reliability of the chip. Therefore, in this embodiment, the first preset length H1 is 10% to 50% of the length of the first side.

[0059] It should be noted that the ratio of the second preset length H2 to the first preset length H1 should not be too large or too small. If the ratio is too small, it may lead to excessive stress at the corners of the subsequently formed target layer, failing to effectively improve stress concentration. When other films cover the target layer, this increases the probability of cracks appearing at the corners of the target layer. If the ratio is too large, it increases the probability of short circuits between different metal lines, thus affecting the reliability of the chip. Therefore, in this embodiment, the second preset length H2 is √2 to √3 times the first preset length H1.

[0060] Execute step S22, compare the length L1 of the first side 160 with the first preset length H1, and the length L2 of the second side 161 with the first preset length H1.

[0061] As described above, the right-angled corner is subsequently chamfered to become an obtuse corner. This is equivalent to adding a triangular corner appendage at the right-angled corner. Therefore, by comparing the lengths first, the rules for chamfering the right-angled corner are determined. These rules include: according to the length of the right-angled side, corresponding line segments are cut from the first side 160 and the second side 161 respectively; or, according to the length of the hypotenuse and based on the Pythagorean theorem, corresponding line segments are cut from the first side 160 and the second side 161 respectively.

[0062] In step S231, when the length L1 of the first side 160 and the length L2 of the second side 161 are both greater than the first preset length H1, at the right-angle corner, the first side 160 of the first preset length H1 is cut off as the first line segment, and the second side 161 of the first preset length H1 is cut off as the second line segment; the first line segment and the second line segment are replaced with the third side, and the first line segment, the second line segment and the third side form a triangle.

[0063] By forming a triangle at the right-angle corner, the first side 160 and the second side 161 change from right-angle corners to obtuse corners. Subsequently, after forming a target layer on the base corresponding to the main graphic, the corners of the target layer are also obtuse.

[0064] Since the length L1 of the first side 160 and the length L2 of the second side 161 are both greater than the first preset length H1, the triangle can be one or both of isosceles triangles and non-isosceles triangles, depending on the length of the corresponding line segments cut from the first side 160 and the second side 161.

[0065] As one example, such as Figure 4 (a) and Figure 4 As shown in (c), the triangle is an isosceles triangle (i.e., the lengths of the first line segment and the second line segment are equal), thereby reducing the complexity of chamfering the right-angle corner.

[0066] It should be noted that the angle A1 between the third side and the first side 160 should not be too large or too small. If the angle A1 between the third side and the first side 160 is too large, with the second preset length H2 fixed, the angle between the third side and the second side 161 is likely to be close to a right angle, resulting in the corner of the target layer subsequently formed on the substrate also being a right angle. Consequently, this increases the stress of the target layer at the corner, increases the probability of cracks appearing in the film layer covering the target layer at the corner of the target layer, and thus reduces chip reliability. If the angle A1 between the third side and the first side 160 is too small, with the second preset length H2 fixed, the angle between the third side and the first side 160 is likely to be close to a right angle, resulting in the corner of the target layer subsequently formed on the substrate also being a right angle. Consequently, this increases the stress of the target layer at the corner, increases the probability of cracks appearing in the film layer covering the target layer at the corner of the target layer, and thus reduces chip reliability. Therefore, in this embodiment, the included angle A1 between the third side and the first side 160 is between 10 degrees and 80 degrees. For example, the included angle between the third side and the first side 160 is 20 degrees, 40 degrees, or 60 degrees.

[0067] It should also be noted that the angle A2 between the third side and the second side 161 should not be too large or too small. If the angle A2 between the third side and the second side 161 is too large, with the second preset length H2 fixed, the angle between the third side and the first side 160 is likely to be close to a right angle, resulting in the corner of the target layer subsequently formed on the substrate also being a right angle. Consequently, this increases the stress of the target layer at the corner, increases the probability of cracks appearing in the film layer covering the target layer at the corner of the target layer, and thus reduces chip reliability. If the angle A2 between the third side and the second side 161 is too small, with the second preset length H2 fixed, the angle between the third side and the second side 161 is likely to be close to a right angle, resulting in the corner of the target layer subsequently formed on the substrate also being a right angle. Consequently, this increases the stress of the target layer at the corner, increases the probability of cracks appearing in the film layer covering the target layer at the corner of the target layer, and thus reduces chip reliability. Therefore, in this embodiment, the included angle A2 between the third side and the second side 161 is between 10 degrees and 80 degrees. For example, the included angle between the third side and the second side 161 is 20 degrees, 40 degrees, or 60 degrees.

[0068] like Figure 4As shown in (b), when the length of either the first side 160 or the second side 161 is less than or equal to the first preset length H1, according to the second preset length H2, at the right-angle corner, the first side with a third preset length H3 is cut off as the first line segment, and the second side 161 with a fourth preset length H4 is cut off as the second line segment; the first line segment and the second line segment are replaced with the third side, the length of the third side is the second preset length H2, and the first line segment, the second line segment and the third side form a triangle.

[0069] By forming a triangle at the right-angle corner, the first side 160 and the second side 161 change from right-angle corners to obtuse corners. Subsequently, after forming a target layer on the base corresponding to the main graphic, the corners of the target layer are also obtuse.

[0070] Since the length of either the first side 160 or the second side 161 is less than or equal to the first preset length H1, the third preset length H3 and the fourth preset length H4 can be set according to the lengths of the first side and the second side while the second preset length H2 is fixed.

[0071] It is understandable that the second preset length H2 is the length of the hypotenuse of the triangle. Therefore, the second preset length H2, the third preset length H3, and the fourth preset length H4 satisfy the Pythagorean theorem. This is equivalent to determining the length of the right-angled side of the triangle while keeping the length of the hypotenuse fixed.

[0072] As one embodiment, the triangle is a non-isosceles triangle (i.e., the third preset length H3 is greater than the fourth preset length H4).

[0073] Specifically, in order to form a complete triangle at the right-angle corner, when the third preset length H3 is determined according to the second preset length H2, the third preset length H3 is less than or equal to the length of the first side, thereby ensuring that the first line segment is still located on the first side, so as to achieve the effect of correcting only the corner, reducing the probability of having additional influence on the shape of the main graphic, and also facilitating the confirmation that an obtuse corner can be obtained after correction.

[0074] In this embodiment, in order to form a complete triangle at the right-angle corner, when the fourth preset length H4 is determined according to the second preset length H2, the fourth preset length H4 is less than or equal to the length of the second side 161, thereby ensuring that the second line segment is still located on the second side 161, so as to achieve the effect of correcting only the corner, reducing the probability of having additional influence on the shape of the main graphic, and also facilitating the confirmation that an obtuse corner can be obtained after correction.

[0075] It should be noted that when the concave and convex corners of adjacent main graphics 101 are opposite each other, after optical proximity correction processing is performed on the main graphics, it must be ensured that the adjacent corrected graphics will not come into contact. However, after chamfering the right-angle corner, it is equivalent to adding an additional corner graphic at the right-angle corner, which increases the area of ​​the corrected graphic. Therefore, the first preset length should not be too large to ensure a safe distance between the third side and the adjacent convex corner, thereby reducing the probability of adjacent corrected graphics with opposite concave and convex corners coming into contact.

[0076] Specifically, according to chip design requirements, adjacent main patterns 101 have different spacings in the design pattern. For example, as Figure 4 (c) When the minimum value d between adjacent main graphics 101 is the minimum interval.

[0077] In this embodiment, a perpendicular line to the third side is drawn with the intersection of the first side and the second side as the vertex. The perpendicular line is used as the fifth preset length H5. As an example, the fifth preset length is less than 0.6 to 0.8 times the minimum interval.

[0078] It should be noted that the multiple of the fifth preset length H5 and the minimum interval should not be too large. If the multiple of the fifth preset length and the minimum interval is too large, the probability of the triangle touching the convex corner of the adjacent main graphic 101 will increase, thereby affecting the reliability of the chip.

[0079] This embodiment uses a chamfering process on the right-angled corners to correct for optical proximity effects in the main graphic. In other embodiments, the right-angled corners can also be rounded.

[0080] refer to Figure 6 The steps for rounding the right-angle corner include: determining a preset radius of curvature; obtaining the inscribed circle of the right-angle corner based on the preset radius of curvature, wherein the inscribed circle is tangent to the first side at a first point of tangency D, and the inscribed circle is tangent to the second side at a second point of tangency C, and the arc between the first point of tangency D and the second point of tangency C is used as the third side M; and replacing the first side 170 between the first point of tangency D and the right-angle corner, and the second side 171 between the second point of tangency C and the right-angle corner, with the third side M.

[0081] Specifically, by rounding the corners, right-angled corners are transformed into rounded corners. After the target pattern is transferred to the substrate to form the target layer, the corners of the target layer are rounded, which reduces the stress at the corners and improves the stress concentration problem. When other films cover the target layer, the stress at the corners of the target layer will affect the other films. Therefore, by reducing the stress at the corners of the target layer, the probability of cracks appearing at the corners of the target layer is reduced, thereby improving chip reliability.

[0082] Accordingly, the present invention also provides an optical proximity correction system. Figure 7 This is a functional block diagram of an embodiment of the optical proximity correction system of the present invention.

[0083] In this embodiment, the optical proximity correction system 50 includes: a graphic providing module 501, used to provide a design graphic, the design graphic including multiple main graphics, the main graphics having right-angle corners; and a graphic correction module 502, used to perform optical proximity effect correction processing on the main graphics to obtain a corrected graphic, the optical proximity effect correction processing including chamfering or rounding the right-angle corners.

[0084] The pattern correction module 502 is used to perform optical proximity effect correction processing on the main pattern. By performing chamfering, right-angle corners are changed to obtuse corners, or by performing rounding, right-angle corners are changed to rounded corners. Correspondingly, after the corrected pattern is transferred to the substrate to form the target layer, the corners of the target layer are obtuse or rounded, which reduces the stress at the corners of the target layer and can improve the stress concentration problem. When other films are covered around the target layer, the stress at the corners of the target layer will affect the other films. Therefore, by reducing the stress at the corners of the target layer, the probability of cracks appearing at the corners of the target layer is reduced, thereby improving chip reliability.

[0085] The pattern providing module 501 is used to provide design patterns, so that after optical proximity correction is performed on the design patterns, the obtained patterns are used to make a mask, and then the mask is used to perform photolithography to form the corresponding mask pattern on the wafer.

[0086] like Figure 3 (a) Figure 3 (b) and Figure 3 As shown in (c), in this embodiment, the plurality of main graphics 101 may have different shapes and layouts according to design requirements.

[0087] In this embodiment, the main pattern 101 is a metal line pattern. After the metal line pattern is transferred to the substrate to form a target pattern, the target pattern is a metal line. The metal line is used to electrically connect the interconnect structure in the semiconductor device to an external circuit.

[0088] It should be noted that the metal lines are divided into interlayer metal lines and top layer metal lines. The layer covering the interlayer metal lines is a dielectric layer, and the layer covering the top layer metal lines is a passivation layer. In this embodiment, the metal line corresponding to the metal line pattern is the top layer metal line.

[0089] In this embodiment, the main graphic 101 has a right-angle corner (such as...). Figure 3 (As shown in the dashed circle).

[0090] In this embodiment, the right-angle corner includes one or both of concave and convex corners. As an example, the right-angle corners to be optically proximity corrected are all concave corners.

[0091] In this embodiment, the main graphic 101 is formed by multiple sides, the right-angle corner is formed by the intersection of two adjacent perpendicular sides, the included angle between the two adjacent sides corresponding to the concave corner is 90°, and the included angle between the two adjacent sides corresponding to the convex corner is 270°.

[0092] Specifically, taking any right-angled corner of any main graphic 101 as an example, the right-angled corner is formed by the intersection of the first perpendicular side 160 and the second perpendicular side 161.

[0093] The perpendicular first side 160 and the second side 161 provide the basis for subsequent chamfering or rounding of the right-angle corner.

[0094] In this embodiment, since the shape and layout of the target graphic (e.g., metal wire) are inconsistent, there is a case where the spacing d between adjacent main graphics 101 is at its minimum value.

[0095] For example, Figure 3 (c) The spacing d between adjacent main graphics 101 shown is the minimum value among all spacing distances.

[0096] This embodiment uses the graphic correction module 502 to perform chamfering on the right-angle corner as an example for illustration.

[0097] In this embodiment, the graphic correction module 502 includes: a size preset unit 503, used to determine a preset right-angle side length as a first preset length and a preset hypotenuse length as a second preset length; a comparison unit 504, used to compare the length of the first side with the first preset length and the length of the second side with the first preset length; and a graphic correction unit 505, used to, when the lengths of the first side and the second side are both greater than the first preset length, at the right-angle corner, cut off the first side of the first preset length as a first line segment, cut off the second side of the first preset length as a second line segment, and replace the first and second line segments with a third side, the first line segment, the second line segment, and the third side forming a triangle; and further used to, when the length of either the first side or the second side is less than or equal to the first preset length, according to the second preset length, at the right-angle corner, cut off the first side of the third preset length as a first line segment, cut off the second side of the fourth preset length as a second line segment, and replace the first and second line segments with a third side, the length of the third side being the second preset length, and the first line segment, the second line segment, and the third side forming a triangle.

[0098] The graphic correction module 502 transforms right-angled corners into obtuse-angled corners, which is equivalent to adding a triangular corner appendage graphic at the right-angled corner. Correspondingly, the right-angled side is the right-angled side of the triangle, and the length is the hypotenuse of the triangle.

[0099] Therefore, by first determining the first preset length and the second preset length through the size preset unit 503, it can be compared with the length of the first side and the length of the second side of the right-angle corner to determine the specific method of chamfering the right-angle corner.

[0100] It should be noted that the ratio of the first preset length to the first side length should not be too large or too small. If the ratio is too small, it may lead to excessive stress at the corners of the subsequently formed target layer, failing to effectively improve stress concentration. When other films cover the target layer, this increases the probability of cracks appearing at the corners of the target layer. If the ratio is too large, it increases the probability of short circuits between different metal lines, thus affecting the reliability of the chip. Therefore, in this embodiment, the first preset length is 10% to 50% of the first side length.

[0101] It should be noted that the ratio of the second preset length to the first preset length should not be too large or too small. If the ratio is too small, it may lead to excessive stress at the corners of the subsequently formed target layer, failing to effectively improve stress concentration. When other films cover the target layer, this increases the probability of cracks appearing at the corners of the target layer. If the ratio is too large, it increases the probability of short circuits between different metal lines, thus affecting the reliability of the chip. Therefore, in this embodiment, the second preset length is [a certain percentage] of the first preset length. Doubled times.

[0102] The comparison unit 504 determines the rules for subsequent chamfering of the right-angle corner by comparing the lengths. The rules include: cutting corresponding line segments from the first side and the second side according to the length of the right-angle side, or cutting corresponding line segments from the first side and the second side according to the length of the hypotenuse and based on the Pythagorean theorem.

[0103] The graphic correction unit 505 is used to form a triangle at the right-angle corner, so that the first side and the second side change from right-angle corner to obtuse corner. After a target layer corresponding to the corrected graphic is formed on the base, the corner of the target layer is also obtuse.

[0104] Since the lengths of the first side and the second side are both greater than the first preset length, the triangle can be one or both of isosceles triangles and non-isosceles triangles, depending on the lengths of the corresponding line segments cut from the first side 160 and the second side 161.

[0105] As an example, the triangle is an isosceles triangle (i.e., the lengths of the first line segment and the second line segment are equal), thereby reducing the complexity of the graphic correction unit 505 in performing chamfering on the right-angled corner.

[0106] It should be noted that if the angle between the third side and the first side is too large, given a fixed second preset length, the angle between the third side and the second side is likely to approach a right angle. This results in the corners of the target layer subsequently formed on the substrate also being right angles, consequently increasing the stress on the target layer at the corners and raising the probability of cracks appearing in the film covering the target layer at the corners, thus reducing chip reliability. Conversely, if the angle between the third side and the first side is too small, given a fixed second preset length, the angle between the third side and the first side is likely to approach a right angle, resulting in the corners of the target layer subsequently formed on the substrate also being right angles. This again increases the stress on the target layer at the corners and raises the probability of cracks appearing in the film covering the target layer at the corners, further reducing chip reliability. Therefore, in this embodiment, the angle between the third side and the first side is between 10 degrees and 80 degrees. For example, the angle between the third side and the first side is 20 degrees, 40 degrees, or 60 degrees.

[0107] It should also be noted that the angle between the third side and the second side should not be too large or too small. If the angle between the third side and the second side is too large, given a fixed second preset length, the angle between the third side and the first side is likely to approach a right angle, resulting in a right angle at the corner of the target layer formed on the substrate. This increases the stress on the target layer at the corner, raising the probability of cracks appearing in the film covering the target layer at the corner, thus reducing chip reliability. Conversely, if the angle between the third side and the second side is too small, given a fixed second preset length, the angle between the third side and the second side is likely to approach a right angle, resulting in a right angle at the corner of the target layer formed on the substrate. This also increases the stress on the target layer at the corner, raising the probability of cracks appearing in the film covering the target layer at the corner, thus reducing chip reliability. Therefore, in this embodiment, the angle between the third side and the second side is between 10 degrees and 80 degrees. For example, the angle between the third side and the second side is 20 degrees, 40 degrees, or 60 degrees.

[0108] Since the length of either the first side or the second side is less than or equal to the first preset length, the graphic correction unit 505 can set a third preset length and a fourth preset length based on the lengths of the first side and the second side while keeping the second preset length fixed.

[0109] It is understandable that the second preset length is the length of the hypotenuse of the triangle. Therefore, the second, third, and fourth preset lengths satisfy the Pythagorean theorem. This is equivalent to determining the lengths of the right-angled legs of the triangle while keeping the length of the hypotenuse fixed.

[0110] As one embodiment, the triangle is a non-isosceles triangle (i.e., the third preset length is greater than the fourth preset length).

[0111] Specifically, in order to form a complete triangle at the right-angle corner, when the third preset length is determined according to the second preset length, the third preset length is less than or equal to the length of the first side, thereby ensuring that the first line segment is still located on the first side, so as to achieve the effect of only correcting the corner, reducing the probability of having additional impact on the shape of the main graphic, and also facilitating the confirmation that an obtuse corner can be obtained after correction.

[0112] It should be noted that when concave and convex corners of adjacent main graphics face each other, after optical proximity correction processing of the main graphics, it is necessary to ensure that the adjacent corrected graphics do not come into contact, thereby ensuring the reliability of the chip. However, after chamfering the right-angle corner, it is equivalent to adding an additional corner graphic at the right-angle corner, which increases the area of ​​the corrected graphic. Therefore, the first preset length should not be too large to ensure a safe distance between the third side and the adjacent convex corner, thereby reducing the probability of adjacent corrected graphics with concave and convex corners coming into contact.

[0113] Specifically, depending on the chip design requirements, adjacent main patterns have different spacings in the design pattern.

[0114] In this embodiment, a perpendicular line to the third side is drawn with the intersection of the first side and the second side as the vertex. The perpendicular line is used as the fifth preset length. As an example, the fifth preset length is less than 0.6 to 0.8 times the minimum interval.

[0115] It should be noted that the multiple of the fifth preset length and the minimum interval should not be too large. If the multiple of the fifth preset length and the minimum interval is too large, the probability of the triangle touching the convex corner of the adjacent main graphic increases, thereby affecting the reliability of the chip.

[0116] In this embodiment, the optical proximity correction system performs optical proximity effect correction on the main graphic by chamfering the right-angle corners.

[0117] In other embodiments, the optical proximity correction system may also round the right-angle corners.

[0118] Accordingly, the graphic correction module includes a size preset unit and a graphic correction unit.

[0119] Specifically, the size preset unit is used to determine the preset radius of curvature.

[0120] The graphic correction unit is used to obtain the inscribed circle of the right-angle corner according to the preset radius of curvature. The inscribed circle is tangent to the first side at a first point of tangency, and the inscribed circle is tangent to the second side at a second point of tangency. The arc between the first point of tangency and the second point of tangency is used as the third side. The first side between the first point of tangency and the right-angle corner, and the second side between the second point of tangency and the right-angle corner are replaced with the third side.

[0121] By transforming right-angled corners into rounded corners, the target pattern is transferred to the substrate to form a target layer. The rounded corners of the target layer reduce the stress at the corners, thus improving the stress concentration problem. When other films cover the target layer, the stress at the corners of the target layer can affect these other films. Therefore, by reducing the stress at the corners of the target layer, the probability of cracks appearing at the corners of the target layer is reduced, thereby improving chip reliability.

[0122] Accordingly, the present invention also provides a photomask, comprising: a pattern obtained using the optical proximity correction method provided in the embodiments of the present invention.

[0123] As can be seen from the foregoing embodiments, the embodiments of the present invention perform optical proximity effect correction processing on the main pattern. The optical proximity effect correction processing includes chamfering or rounding the right-angle corners. By chamfering, the right-angle corners are changed into obtuse corners, or by rounding, the right-angle corners are changed into rounded corners. Correspondingly, a mask is prepared using the corrected pattern obtained by the optical proximity correction method, and the corrected pattern is transferred to the substrate using the mask to form a target layer. The corners of the target layer are obtuse or rounded, which reduces the stress at the corners of the target layer and can improve the stress concentration problem. When other films cover the target layer, the stress at the corners of the target layer will affect the other films. Therefore, by reducing the stress at the corners of the target layer, the probability of cracks appearing at the corners of the target layer covered by the films covering the target layer is reduced, thereby improving chip reliability.

[0124] This invention also provides a device that can implement the optical proximity correction method provided in this invention through the above-described graphical design method in the form of a loaded program. An optional hardware structure of the terminal device provided in this invention can be as follows: Figure 8As shown, it includes: at least one processor 01, at least one communication interface 02, at least one memory 03, and at least one communication bus 04.

[0125] In this embodiment, the number of processor 01, communication interface 02, memory 03, and communication bus 04 is at least one, and the processor 01, communication interface 02, and memory 03 communicate with each other through communication bus 04. Communication interface 02 can be an interface of a communication module for network communication, such as the interface of a GSM module. Processor 01 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. Memory 03 may include high-speed RAM and may also include non-volatile memory (NVM), such as at least one disk storage device. Memory 03 stores one or more computer instructions, which are executed by processor 01 to implement the optical proximity correction method provided in this embodiment of the present invention.

[0126] It should be noted that the aforementioned terminal device may also include other devices (not shown) that may not be essential to understanding the content disclosed in the embodiments of the present invention; given that these other devices may not be essential for understanding the content disclosed in the embodiments of the present invention, the embodiments of the present invention will not describe them one by one.

[0127] This invention also provides a storage medium storing one or more computer instructions for implementing the optical proximity correction method provided in this invention.

[0128] Embodiments of the present invention can be implemented by various means, such as hardware, firmware, software, or combinations thereof. In a hardware configuration, the method according to an exemplary embodiment of the present invention can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc. In a firmware or software configuration, embodiments of the present invention can be implemented in the form of modules, processes, functions, etc. Software code can be stored in memory units and executed by a processor. The memory units are located inside or outside the processor and can send data to and receive data from the processor via various known means.

[0129] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. An optical proximity correction method, characterized in that, include: Provide a design graphic, which includes multiple main graphics, each main graphic having right-angled corners; The main pattern is subjected to optical proximity effect correction processing to obtain a corrected pattern. The optical proximity effect correction processing includes chamfering or rounding the right-angle corners to reduce the stress at the corners of the target layer formed after the corrected pattern is transferred to the substrate. In the step of providing the design graphic, the main graphic is a metal line graphic, and the metal line graphic is a top-level metal line graphic.

2. The optical proximity correction method as described in claim 1, characterized in that, In the step of providing the design drawing, the right-angle corner is formed by the intersection of a first side and a second side that are perpendicular to each other; The steps for chamfering the right-angle corner include: determining a preset right-angle side length as a first preset length and a preset hypotenuse length as a second preset length; Compare the length of the first side with the first preset length, and the length of the second side with the first preset length; When the lengths of the first side and the second side are both greater than the first preset length, at the right-angle corner, the first side of the first preset length is cut off as the first line segment, and the second side of the first preset length is cut off as the second line segment; the first line segment and the second line segment are replaced with the third side, and the first line segment, the second line segment and the third side form a triangle; When the length of either the first side or the second side is less than or equal to the first preset length, according to the second preset length, at the right-angle corner, the first side of a third preset length is cut off as the first line segment, and the second side of a fourth preset length is cut off as the second line segment; the first line segment and the second line segment are replaced with the third side, the length of the third side is the second preset length, and the first line segment, the second line segment and the third side form a triangle.

3. The optical proximity correction method as described in claim 2, characterized in that, The first preset length is 10% to 50% of the length of the first side.

4. The optical proximity correction method as described in claim 2, characterized in that, The second preset length is the first preset length. .

5. The optical proximity correction method as described in claim 2, characterized in that, The angle between the third side and the first side is 10 degrees to 80 degrees; the angle between the third side and the second side is 10 degrees to 80 degrees.

6. The optical proximity correction method as described in claim 2, characterized in that, The third preset length is less than or equal to the length of the first side; the fourth preset length is less than or equal to the length of the second side.

7. The optical proximity correction method as described in claim 2, characterized in that, In the step of providing design graphics, the minimum value of the interval between adjacent main graphics is the minimum interval. Draw a perpendicular line to the third side with the intersection of the first and second sides as the vertex, and the perpendicular line is used as the fifth preset length; The fifth preset length is less than 0.6 to 0.8 times the minimum interval.

8. The optical proximity correction method as described in claim 1, characterized in that, In the step of providing the design drawing, the right-angle corner is formed by the intersection of a first side and a second side that are perpendicular to each other; The steps for rounding the right-angle corner include: determining a preset radius of curvature; obtaining the inscribed circle of the right-angle corner based on the preset radius of curvature, wherein the inscribed circle is tangent to the first side at a first point of tangency, the inscribed circle is tangent to the second side at a second point of tangency, and the arc between the first point of tangency and the second point of tangency is used as the third side; and replacing the first side between the first point of tangency and the right-angle corner, and the second side between the second point of tangency and the right-angle corner, with the third side.

9. An optical proximity correction system, characterized in that, include: A graphics providing module is used to provide design graphics, which include multiple main graphics, and the main graphics have right-angle corners; The pattern correction module is used to perform optical proximity effect correction processing on the main pattern to obtain a corrected pattern. The optical proximity effect correction processing includes chamfering or rounding the right-angle corners to reduce the stress at the corners of the target layer formed after the corrected pattern is transferred to the substrate. In the step of providing the design graphic, the main graphic is a metal line graphic, and the metal line graphic is a top-level metal line graphic.

10. A photomask, characterized in that, include: The image obtained using the optical proximity correction method as described in any one of claims 1-8.

11. A device, characterized in that, include: At least one memory and at least one processor, the memory storing one or more computer instructions, wherein the one or more computer instructions are executed by the processor to implement the optical proximity correction method as described in any one of claims 1-8.

12. A storage medium, characterized in that, The storage medium stores one or more computer instructions for implementing the optical proximity correction method as described in any one of claims 1-8.

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