Method for target pattern correction, mask production and semiconductor structure formation

Abstract

A method for correcting a target pattern, a method for making a mask, and a method for forming a semiconductor structure, wherein the method for correcting a target pattern comprises: providing a target pattern, wherein the target pattern extends along a first direction; dividing the target pattern into a first central area and two first edge areas located on both sides of the first central area; dividing the edge of the target pattern in each of the first edge areas into a plurality of edges to be compensated; obtaining an etching offset model; and performing a first compensation correction on each edge to be compensated according to the etching offset model to obtain a first compensation edge. The method is conducive to improving the uniformity of the size of the pattern obtained after etching.

Description

Technical Field

[0001] The invention relates to the field of semiconductor manufacturing technology, and in particular to a method for correcting a target pattern, making a mask and forming a semiconductor structure. Background Art

[0002] At present, with the development of ultra-large-scale integrated circuits, device design sizes are getting smaller and smaller, and changes in the critical dimensions (CD) of devices have an increasing impact on device performance. For example, changes in the critical dimensions of gate structures will directly lead to changes in device operating speed.

[0003] Photolithography is a crucial technology in semiconductor manufacturing technology. Photolithography can transfer patterns from the mask to the surface of the silicon wafer to form semiconductor products that meet the design requirements. The photolithography process includes an exposure step, a development step after the exposure step, and an etching step after the development step. In the exposure step, light is irradiated onto the silicon wafer coated with photoresist through the light-transmitting area in the mask, and the photoresist undergoes a chemical reaction under the irradiation of light; in the development step, the photolithography pattern is formed by utilizing the different degrees of solubility of the photosensitive and non-photosensitive photoresists in the developer, and the mask pattern is transferred to the photoresist; in the etching step, the silicon wafer is etched based on the photolithography pattern formed by the photoresist layer, and the mask pattern is further transferred to the silicon wafer.

[0004] The size of a specific pattern after photolithography is characterized by ADI (After Develop Inspection) CD (Critical Dimension), and AEI (After Etch inspection) CD is the size of the device after etching. The difference between ADICD and AEI CD is the etching bias.

[0005] However, in the prior art, a target pattern is corrected by etching deviation to obtain a mask pattern, and then the mask pattern is transferred to a silicon wafer, and the feature sizes of the two ends and the center of the obtained pattern are inconsistent. Summary of the invention

[0006] The technical problem solved by the present invention is to provide a method for correcting a target pattern, making a mask and forming a semiconductor structure, so as to improve the uniformity of the pattern size obtained after etching.

[0007] In order to solve the above technical problems, the technical solution of the present invention provides a method for correcting a target graphic, including: providing a target graphic, and the target graphic extends along a first direction; dividing the target graphic into a first central area and two first edge areas respectively located on both sides of the first central area; dividing the edge of the target graphic in each of the first edge areas into a number of edges to be compensated; obtaining an etching offset model; and performing a first compensation correction on each edge to be compensated according to the etching offset model to obtain a first compensation edge.

[0008] Optionally, when the size of the target graphic along the first direction is greater than a preset value, the method of dividing the target graphic into a first central area and two first edge areas includes: obtaining the size l of the target graphic in the first direction long ; Obtain a first central area in the target graphic, the size of the first central area along the first direction is l1, and l1 is greater than or equal to the minimum segmentation value l min ; Obtain a first edge region in the target graphic, the size of the first edge region along the first direction is l0, and satisfies l0=(l long -l1) / 2.

[0009] Optionally, the method of dividing the edge of each target pattern in the first edge region into a plurality of edges to be compensated includes: dividing the edge of the target pattern in the first edge region into N edges to be compensated along the first direction, where N is l. long / l min An integer value; obtaining a first edge to be compensated from the plurality of edges to be compensated, the first edge to be compensated being the edge to be compensated that is farthest from the first central area in the first direction, and the size of the first edge to be compensated is l0-(N-1)l min The sizes of the (N-1) edges to be compensated other than the first edge to be compensated are all the minimum segmentation value l min .

[0010] Optionally, the etching offset model includes: a first correction model and a second correction model; the method for obtaining the etching offset model includes: providing a second test pattern, the size of the second test pattern in the first direction is greater than a preset value; using the second test pattern as a mask, performing an exposure process, a development process and an etching process, and obtaining a second etching pattern; dividing the second etching pattern into a second central area and two second edge areas respectively located on both sides of the first central area, and the size of the second edge area is l0; dividing each second edge area into a plurality of segmented patterns along the first direction, among which the segmented pattern farthest from the second central area is the first segmented pattern, and the size of the first segmented pattern along the first direction is l0-(N-1)l min ; Measure the size CD of the first segmentation pattern AEI_end ; Get CDAEI ;According to CD AEI_end and CD AEI , the first revised model is obtained as follows:

[0011] f(1)=CD AEI_end -CD AEI ;

[0012] According to the first correction model f(1), the second correction model is obtained as follows:

[0013]

[0014] And 2≤x≤N, N is a natural number greater than or equal to 2.

[0015] Optionally, the first compensation correction method includes: compensating and correcting the first edge to be compensated in each first edge zone according to a first correction model; compensating and correcting the xth edge to be compensated in the first edge zone according to a second correction model, and 2≤x≤N, N is a natural number greater than or equal to 2.

[0016] Optionally, when the size of the target graphic along the first direction is smaller than a preset value, the method for dividing the target graphic into a first central area and two first edge areas includes: obtaining the size l of the target graphic in the first direction; short ; Obtain a first central area in the target graphic, the size of the first central area along the first direction is l3, and l3 is equal to the minimum segmentation value l min ; Obtain a first edge region in the target graphic, the size of the first edge region along the first direction is l2, and satisfies l2=(l short -l3) / 2.

[0017] Optionally, the method of dividing the edge of the target graphic in each first edge area into a plurality of edges to be compensated includes: dividing the edge of the target graphic in the first edge area into N edges to be compensated along the first direction, where N is l. short / l min An integer value; obtaining a first edge to be compensated from the plurality of edges to be compensated, the first edge to be compensated being the edge to be compensated that is farthest from the first central area in the first direction, and the size of the first edge to be compensated is l2-(N-1)l min The sizes of the (N-1) edges to be compensated other than the first edge to be compensated are all the minimum segmentation value l min .

[0018] Optionally, the etching offset model includes: a third correction model, a fourth correction model and a fifth correction model; the method for obtaining the etching offset model includes: providing a third test pattern, wherein the size of the third test pattern in the first direction is smaller than a preset value; using the third test pattern as a mask, performing an exposure process, a development process and an etching process to obtain a third etching pattern; dividing the third etching pattern into a third central area and two third edge areas located on both sides of the third central area, and the size of the third edge area is l2; dividing each of the third etching patterns into a plurality of segmented patterns, wherein the segmented pattern farthest from the third central area is a first segmented pattern, and the size of the first segmented pattern along the first direction is l2-(N-1)l min ; Measure the size CD of the first segmentation pattern AEI_end_short ; Measure the size CD of the third etching pattern in the third central area AEI_short ; Get CD AEI ;According to CD AEI_end_short and CD AEI_short , and CD AEI , the third revised model is obtained as follows:

[0019] f(0)=CD AEI_short -CD AEI ;

[0020] According to the third correction model, the fourth correction model is obtained as f(1)=CD AEI_end_short -CD AEI_short +f(0);

[0021] According to the third and fourth correction models, the fifth correction model is obtained as follows:

[0022]

[0023] And 2≤x≤N, N is a natural number greater than or equal to 2.

[0024] Optionally, the first compensation correction also includes: compensating and correcting the edge of the target figure in the first central area; the second compensation correction method includes: compensating and correcting the edge of the target figure in the first central area according to the third correction model; compensating and correcting the first edge to be compensated in each first edge area according to the fourth correction model; compensating and correcting the xth edge to be compensated in each first edge area according to the fifth correction model, and 2≤x≤N, N is a natural number greater than or equal to 2.

[0025] Optionally, the CD AEIThe method for obtaining the first test pattern includes: providing a first test pattern; using a mask plate made of the first test pattern as a mask, performing an exposure process and a development process to obtain a first photolithography pattern; using the first photolithography pattern as a mask, performing an etching process to obtain a first etching pattern; measuring and obtaining a second characteristic dimension CD of the first etching pattern AEI .

[0026] Optionally, the method further includes: measuring a first characteristic dimension CD of a first photolithographic pattern; ADI ; The method for obtaining the target pattern includes: measuring the first characteristic size CD of the first photolithography pattern ADI According to the first characteristic size CD ADI and the second characteristic size CD AEI The difference between them is used to obtain the compensation value ΔCD etching bias =CD ADI -CD AEI ; Providing an initial target graph; According to the compensation value ΔCD etching bias , performing a second compensation correction on the initial target graphic to obtain the target graphic.

[0027] Optionally, the CD AEI The method for obtaining the first test pattern includes: providing a first test pattern; using a mask plate made of the first test pattern as a mask, performing an exposure process and a development process to obtain a first photolithography pattern; using the first photolithography pattern as a mask, performing an etching process to obtain a first etching pattern; measuring and obtaining a second characteristic dimension CD of the first etching pattern AEI .

[0028] Optionally, the method further includes: measuring a first characteristic dimension CD of a first photolithographic pattern; ADI ; The method for obtaining the target pattern includes: measuring the first characteristic size CD of the first photolithography pattern ADI According to the first characteristic size CD ADI and the second characteristic size CD AEI The difference between them is used to obtain the compensation value ΔCD etching bias =CD ADI -CD AEI ; Providing an initial target graph; According to the compensation value ΔCD etching bias , performing a second compensation correction on the initial target graphic to obtain the target graphic.

[0029] Optionally, the preset value ranges from 700 nanometers to 1500 nanometers.

[0030] Correspondingly, the technical solution of the present invention also provides a method for manufacturing a mask, including: providing a target graphic, and the target graphic extends along a first direction; dividing the target graphic into a first central area and two first edge areas respectively located on both sides of the first central area; dividing the edge of the target graphic in each of the first edge areas into a number of edges to be compensated; obtaining an etching offset model; performing a first compensation correction on each edge to be compensated according to the etching offset model to obtain a first compensation edge; and manufacturing a mask with the first compensation edge.

[0031] Correspondingly, the technical solution of the present invention also provides a method for forming a semiconductor structure, comprising: providing a substrate; forming a photoresist on the surface of the substrate; providing a mask, and the method for forming the mask comprises: providing a target pattern, and the target pattern extends along a first direction; dividing the target pattern into a first central area and two first edge areas respectively located on both sides of the first central area; dividing the edge of the target pattern in each of the first edge areas into a number of edges to be compensated; obtaining an etching offset model; performing a first compensation correction on each edge to be compensated according to the etching offset model to obtain a first compensation edge; making a mask with the first compensation edge; using the mask as a mask, exposing the photoresist to form a patterned layer; using the patterned layer as a mask, etching the substrate.

[0032] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0033] In the target pattern correction method provided by the technical solution of the present invention, a first compensation correction is performed on each edge to be compensated according to the etching offset model to obtain a first compensation edge. Since the etching offset model can compensate for the etching loading effect caused by inconsistent pattern density, it is beneficial to the uniformity of the size of the etching pattern formed by the subsequent etching process, that is, the consistency of the size of the first center area and the first edge area of ​​the etching pattern.

[0034] Furthermore, the target pattern is obtained by performing a second compensation correction on the initial target pattern. The second compensation correction can reduce the error caused by etching deviation during the process of transferring the photolithography pattern to the substrate, and the second compensation correction is conducive to improving the accuracy of pattern transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 to Figure 2 It is a structural schematic diagram of each step of a method for correcting a target figure;

[0036] Figure 3 is a schematic flow chart of a method for correcting a target graphic in one embodiment of the present invention;

[0037] Figures 4 to 8 is a structural schematic diagram of each step of a method for correcting a target graphic in one embodiment of the present invention;

[0038] Figures 9 to 13 It is a structural schematic diagram of each step of a method for correcting a target graphic in another embodiment of the present invention. DETAILED DESCRIPTION

[0039] As described in the background art, when the existing target pattern correction method is used for photolithography, the size uniformity of the formed pattern is poor.

[0040] Figure 1 to Figure 2 The present invention is a structural schematic diagram of each step of a target graphics correction method.

[0041] Please refer to Figure 1 , providing a target graphic 100.

[0042] Please refer to Figure 2 , the target pattern 100 is compensated and corrected according to the etching deviation to obtain a compensation pattern 110; wherein the calculation formula of the etching deviation is:

[0043] ΔCD etching bias =CD ADI -CD AEI

[0044] In the above method, the CD ADI It refers to the characteristic size of the photolithographic pattern obtained after the uncompensated target pattern 100 is subjected to the exposure process and the development process. AEI It refers to the characteristic size of the etched pattern obtained after the uncompensated target pattern 100 is etched. The calculation formula of etching deviation is:

[0045] ΔCD etching bias =CD ADI -CD AEI ;

[0046] Get Etch Bias CD ething bias According to the ΔCD etching bias The target pattern 100 is compensated and corrected to obtain the compensation pattern 110, which can reduce the error caused in the subsequent etching process, so that the etching pattern obtained after the exposure process, development process and etching process with the compensation pattern 110 can be close to the target pattern.

[0047] However, the etching process is easily affected by the sparse distribution of the pattern. The pattern density difference at the end of the target pattern 100 is large, which is easy to produce an etch loading effect, resulting in a large size difference between the end and the center of the etched pattern. etching bias It is single, so the compensation correction performed on the target pattern 100 is also single, and it is impossible to perform more accurate compensation correction on each specific position in the target pattern 100, so that the size uniformity of the obtained etching pattern is still poor.

[0048] In order to solve the above technical problems, an embodiment of the present invention provides a method for correcting a target pattern, comprising: providing a target pattern, wherein the target pattern extends along a first direction; dividing the target pattern into a first central area and two first edge areas respectively located on both sides of the first central area; dividing the edge of the target pattern in each of the first edge areas into a plurality of edges to be compensated; obtaining an etching offset model; and performing a first compensation correction on each edge to be compensated according to the etching offset model to obtain a first compensation edge. The method for correcting the target pattern is conducive to the uniformity of the size of the etching pattern formed by the subsequent etching process.

[0049] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0050] Please refer to Figure 3 , Figure 3 : is a flow chart of a method for correcting a target graphic in one embodiment of the present invention, comprising:

[0051] Step S01: providing a target pattern, wherein the target pattern extends along a first direction;

[0052] Step S02: dividing the target graphic into a first central area and two first edge areas respectively located on both sides of the first central area;

[0053] Step S03: dividing the edge of the target pattern in each of the first edge areas into a plurality of edges to be compensated;

[0054] Step S04: obtaining an etching offset model;

[0055] Step S05: performing a first compensation correction on each edge to be compensated according to the etching offset model to obtain a first compensation edge.

[0056] According to the etching offset model, each edge to be compensated is respectively subjected to a first compensation correction to obtain a first compensation edge. Since the etching offset model can compensate for the etching loading effect caused by inconsistent pattern density, it is beneficial to the uniformity of the size of the etching pattern formed by the subsequent etching process, that is, the consistency of the size of the first central area of ​​the etching pattern and the size of the first edge area. The following is a specific description with reference to the accompanying drawings.

[0057] Figures 4 to 8 1 is a schematic diagram of the structure of each step of a method for correcting a target graphic in one embodiment of the present invention.

[0058] Please refer to Figure 4 , providing a target pattern 200, and the target pattern 200 extends along a first direction X.

[0059] In this embodiment, the size of the target pattern 200 along the first direction X is 1600 nanometers.

[0060] The target pattern 200 is a pattern designed for a photoresist layer.

[0061] In this embodiment, the method for obtaining the target pattern 200 includes: providing an initial target pattern; etching bias , performing a second compensation correction on the initial target graphic to obtain the target graphic 200.

[0062] Obtain the compensation value ΔCD etching bias The method comprises: providing a first test pattern; using a mask plate made of the first test pattern as a mask, performing an exposure process and a development process to obtain a first photolithography pattern; using the first photolithography pattern as a mask, performing an etching process to obtain a first etching pattern; measuring a second characteristic dimension CD of the first etching pattern AEI ; Measure the first characteristic size CD of the first lithography pattern ADI According to the first characteristic size CD ADI and the second characteristic size CD AEI The difference between them is used to obtain the compensation value ΔCD etching bias =CD ADI -CD AEI .

[0063] The target pattern 200 is obtained by performing a second compensation correction on the initial target pattern. The second compensation correction can reduce the error caused by etching deviation during the process of transferring the photolithography pattern to the substrate, and the second compensation correction is conducive to improving the accuracy of pattern transfer.

[0064] It should be noted that the compensation value ΔCD is used to obtain etching bias, the first characteristic dimension CD ADI and the second characteristic size CD AEI The first test pattern needs to satisfy that a size along the first direction X is greater than a preset value.

[0065] In this embodiment, the target pattern 200 is in the shape of a strip. In other embodiments, the target pattern may also be in the shape of a square.

[0066] In this embodiment, the number of the target graphics 200 is three. In other embodiments, the number of the target graphics is one or more.

[0067] Please refer to Figure 5 , the target graphic 200 is divided into a first central area A1 and two first edge areas B1 respectively located on both sides of the first central area A1.

[0068] The method of dividing the target graphic 200 into a first central area A1 and two first edge areas B1 includes: obtaining a size l of the target graphic 200 in a first direction X long ; Obtain a first central area A1 in the target graphic 200, the size of the first central area A1 along the first direction is l1, and l1 is greater than or equal to the minimum segmentation value l min ; A first edge region B1 is obtained in the target pattern 200, wherein the size of the first edge region B1 along the first direction X is l0, and l0=(l long -l1) / 2.

[0069] Please refer to Figure 6 , Figure 6 for Figure 5 The partially enlarged view of the first edge area B1 of the target pattern 200 shows that the edge of the target pattern 200 in each of the first edge areas B1 is divided into a plurality of edges 210 to be compensated.

[0070] The method of dividing the edge of each target pattern 200 in the first edge area B1 into a plurality of edges 210 to be compensated comprises: dividing the edge of the target pattern 200 in the first edge area B1 into N edges 210 to be compensated along the first direction X, where N is l long / l min An integer value; obtaining a first edge 211 to be compensated from the plurality of edges 210 to be compensated, the first edge 211 to be compensated being the edge 210 to be compensated that is farthest from the first central area A1 in the first direction X, and the size of the first edge 211 to be compensated is l0-(N-1)l min The sizes of the (N-1) to-be-compensated edges 210 other than the first to-be-compensated edge 211 are all the minimum segmentation value l min .

[0071] It should be noted that the l min The value is related to the resolution of the existing photolithography process.

[0072] Please refer to Figure 7 , obtain the etching offset model.

[0073] The preset value ranges from 700 nanometers to 1500 nanometers.

[0074] It should be noted that the preset value is correlated with the size of the target graphic 200 itself, the spacing between adjacent target graphics 200, and the target graphic 200 and surrounding graphics. Therefore, different preset values ​​are set when designing different target graphics.

[0075] In this embodiment, the preset value is set to 800 nanometers, and the size of the target pattern 200 along the first direction X is 1600 nanometers.

[0076] The size of the target pattern 200 is greater than a preset value, and the etching offset model includes: a first correction model and a second correction model; a method for obtaining the etching offset model includes: providing a second test pattern (not shown in the figure), the size of the second test pattern in the first direction X is greater than a preset value; using the second test pattern as a mask, performing an exposure process, a development process and an etching process to obtain a second etching pattern; dividing the second etching pattern into a second central area A2 and two second edge areas B2 located on both sides of the second central area A2, and the size of the second edge area B2 is l0; dividing each second edge area B2 into a plurality of segmentation patterns 320 along the first direction X, among which the segmentation pattern 320 farthest from the second central area B2 is a first segmentation pattern 321, and the size of the first segmentation pattern 321 along the first direction X is l0-(N-1)l min ; Measure the size CD of the first segmentation pattern 321 AEI_end ; Get CD AEI ;According to CD AEI_end and CD AEI , the first revised model is obtained as follows:

[0077] f(1)=CD AEI_end -CD AEI ;

[0078] According to the first correction model f(1), the second correction model is obtained as follows:

[0079]

[0080] And 2≤x≤N, N is a natural number greater than or equal to 2.

[0081] The second correction model is obtained by adjusting the characteristic sizes of the plurality of segmentation patterns 320, such as the size CD of the first segmentation pattern 321. AEI_end , the characteristic size of the second segmentation figure, and the characteristic size of the x-th segmentation figure are obtained by linear simulation, wherein 2≤x≤N, and N is a natural number greater than or equal to 2.

[0082] It should be noted that, in this embodiment, the CD AEI It is obtained by measuring the first etching pattern when the size of the first test pattern along the first direction X is greater than a preset value.

[0083] In other embodiments, the CD AEI It can also be obtained by measuring the characteristic size of the second etched pattern.

[0084] Please refer to Figure 8 , Figure 8 For Figure 6 Based on the structural schematic diagram, a first compensation correction is performed on each edge to be compensated 210 according to the etching offset model to obtain a first compensation edge 250.

[0085] The etching offset model includes: a first correction model and a second correction model, and the first compensation correction method includes: according to the first correction model, compensating and correcting the first edge to be compensated 211 of each first edge area B1; according to the second correction model, compensating and correcting the xth segment of the edge to be compensated 210 of the first edge area B1, and 2≤x≤N, N is a natural number greater than or equal to 2.

[0086] Specifically, when the edge to be compensated 210 is the first edge to be compensated 211, according to the first correction model,

[0087] f(1)=CD AEI_end –CD AEI

[0088] The obtained compensation value enables the first compensation edge 211 to move along a direction perpendicular to the first direction X and reducing the etching deviation by a distance half of the compensation value.

[0089] When the edge 210 to be compensated is an edge 210 to be compensated other than the first edge 211 to be compensated, according to the second correction model,

[0090]

[0091] And 2≤x≤N, N is a natural number greater than or equal to 2, and the compensation value obtained causes the (N-1) edges to be compensated 210, i.e., the second edge to be compensated, the third edge to be compensated, the xth edge to be compensated, and the Nth edge to be compensated, to move a distance of half the compensation value along a direction perpendicular to the first direction X and reducing the etching deviation.

[0092] Specifically, when the edge to be compensated 210 is the second edge to be compensated, x=2 is passed through the second correction model to obtain the compensation value f(2) of the second edge to be compensated.

[0093] In this embodiment, the edge 210 to be compensated is moved along a direction close to the central axis of the target graphic 200 by a distance half of the compensation value.

[0094] According to the etching offset model, each edge to be compensated 210 is respectively subjected to a first compensation correction to obtain a first compensation edge 250. The etching offset model can compensate for the etching loading effect caused by the inconsistent pattern density, thereby facilitating the uniformity of the size of the etching pattern formed by the subsequent etching process, that is, the consistency of the size of the first central area A1 and the first edge area B1 of the etching pattern.

[0095] Figures 9 to 13 It is a structural schematic diagram of each step of a method for correcting a target pattern in another embodiment of the present invention. The difference between this embodiment and the above-mentioned embodiment is that the size of the target pattern along the first direction is different, so that the etching compensation model of the target pattern is different.

[0096] Please refer to Fig. 9 , providing a target pattern 400, and the target pattern 400 extends along a first direction X.

[0097] In this embodiment, the size of the target pattern 400 along the first direction X is 500 nanometers.

[0098] The target pattern 400 is a pattern designed for a photoresist layer.

[0099] The target graphic 400 is the same as the target graphic 200 in the above embodiment, and will not be described in detail herein.

[0100] In this embodiment, the size of the target pattern 400 along the first direction X is 500 nanometers.

[0101] In this embodiment, the size of the target pattern 400 along the first direction X is smaller than a preset value.

[0102] Please refer to Fig.10 , the target graphic 400 is divided into a first central area A1 and two first edge areas B1 respectively located on both sides of the first central area A1.

[0103] The method of dividing the target graphic 400 into a first central area A1 and two first edge areas B1 includes: obtaining a size l of the target graphic 400 in a first direction; short; Obtain a first central area A1 in the target graphic 400, the first central area A1 has a size l3 along the first direction X, and l3 is equal to the minimum segmentation value l min ; A first edge region B1 is obtained in the target pattern 400, the size of the first edge region B1 along the first direction X is l2, and l2=(l short -l3) / 2.

[0104] Please refer to Fig.11 , Fig.11 for Fig.10 The partially enlarged view of the first edge area B1 of the target pattern 400 shows that the edge of each of the first edge areas B1 of the target pattern 400 is divided into a plurality of edges 410 to be compensated.

[0105] The method of dividing the edge of the target pattern 400 in each first edge area B1 into a plurality of edges to be compensated 410 includes: dividing the edge of the target pattern 400 in the first edge area B1 into N edges to be compensated 410 along the first direction X, where N is l short / l min An integer value; obtaining a first edge 411 to be compensated from the plurality of edges 410 to be compensated, the first edge 411 to be compensated being the edge 410 to be compensated that is farthest from the first central area A1 in the first direction X, and the size of the first edge 411 to be compensated is l2-(N-1)l min The sizes of the (N-1) to-be-compensated edges 410 other than the first to-be-compensated edge 411 are all the minimum segmentation value l min .

[0106] It should be noted that the l min The value is related to the resolution of the existing photolithography process.

[0107] Please refer to Fig.12 , obtain the etching offset model.

[0108] The preset value ranges from 700 nanometers to 1500 nanometers.

[0109] In this embodiment, the preset value is set to 800 nanometers, and the size of the target pattern 400 along the first direction X is 500 nanometers.

[0110] The size of the target pattern 400 along the first direction X is smaller than a preset value, and the etching offset model includes: a third correction model, a fourth correction model and a fifth correction model; a method for obtaining the etching offset model includes: providing a third test pattern (not shown in the figure), the size of the third test pattern in the first direction X is smaller than a preset value; using the third test pattern as a mask, performing an exposure process, a development process and an etching process to obtain a third etching pattern; dividing the third etching pattern into a third central area A3 and two third edge areas B3 located on both sides of the third central area A3, and the size of the third edge area B3 is l2; dividing each of the third etching patterns into a plurality of segmented patterns 520, among which the segmented pattern 520 farthest from the third central area A3 is a first segmented pattern 521, and the size of the first segmented pattern 521 along the first direction X is l2-(N-1)l min ; Measure the size CD of the first segmentation pattern 521 AEI_end_short ; Measure the size CD of the third etching pattern of the third central area A3 AEI_short ; Get CD AEI ;According to CD AEI_end_short and CD AEI_short , and CD AEI , the third revised model is obtained as follows:

[0111] f(0)=CD AEI_short -CD AEI ;

[0112] According to the third correction model, the fourth correction model is obtained as f(1)=CD AEI_end_short -CD AEI_short +f(0);

[0113] According to the third and fourth correction models, the fifth correction model is obtained as follows:

[0114]

[0115] And 2≤x≤N, N is a natural number greater than or equal to 2.

[0116] The fifth correction model is obtained by adjusting the characteristic sizes of the plurality of segmentation patterns 520, such as the size CD of the first segmentation pattern 521. AEI_end , the characteristic size of the second segmentation figure, and the characteristic size of the x-th segmentation figure are obtained by linear simulation, wherein 2≤x≤N, and N is a natural number greater than or equal to 2.

[0117] It should be noted that, in this embodiment, the CD AEI It is obtained by measuring the first etching pattern when the size of the first test pattern along the first direction X is greater than a preset value.

[0118] Please refer to Fig.13 , Fig.13 For Fig.12 Based on the structural schematic diagram, a first compensation correction is performed on each edge to be compensated 410 according to the etching offset model to obtain a first compensation edge 370.

[0119] The first compensation correction also includes: compensating and correcting the edge of the target graphic 400 of the first central area A1; the first compensation correction method includes: compensating and correcting the edge of the target graphic 400 of the first central area A1 according to the third correction model; compensating and correcting the first side to be compensated 411 of each first edge area B1 according to the fourth correction model; compensating and correcting the xth side to be compensated of each first edge area B1 according to the fifth correction model, and 2≤x≤N, N is a natural number greater than or equal to 2.

[0120] Specifically, according to the third modified model, f(0) = CD AEI_short -CD AEI , obtain a compensation value, so that the edge of the target pattern 400 in the first central area A1 moves along a direction perpendicular to the first direction X and reducing the etching deviation by a distance half of the compensation value.

[0121] Specifically, when the edge to be compensated 410 is the first edge to be compensated 411, according to the fourth correction model,

[0122] f(1)=CD AEI_end_short -CD AEI_short +f(0);

[0123] A compensation value is obtained, so that the first compensation edge 461 moves along a direction perpendicular to the first direction X and reducing the etching deviation by a distance of half the compensation value.

[0124] When the edge 410 to be compensated is an edge 410 to be compensated other than the first edge 411 to be compensated, according to the fifth correction model,

[0125]

[0126] And 2≤x≤N, N is a natural number greater than or equal to 2, and the compensation value is obtained, so that the (N-1) edges to be compensated 410, that is, the second edge to be compensated, the third edge to be compensated, the xth edge to be compensated, and the Nth edge to be compensated, move a distance of half of the compensation value along a direction perpendicular to the first direction X and reducing the etching deviation.

[0127] Specifically, when the edge to be compensated 410 is the second edge to be compensated, x=2 is passed through the fifth correction model to obtain the compensation value f(2) of the second edge to be compensated.

[0128] In this embodiment, the edge 410 to be compensated is moved along a direction close to the central axis of the target graphic 400 by a distance half of the compensation value.

[0129] Correspondingly, an embodiment of the present invention also provides a method for manufacturing a mask, providing a target graphic, and the target graphic extends along a first direction; dividing the target graphic into a first central area and two first edge areas respectively located on both sides of the first central area; dividing the edge of the target graphic in each of the first edge areas into a number of edges to be compensated; obtaining an etching offset model; performing a first compensation correction on each edge to be compensated according to the etching offset model to obtain a first compensation edge; and manufacturing a mask with the first compensation edge.

[0130] Correspondingly, the present invention also provides a method for forming a semiconductor structure, comprising: providing a substrate; forming a photoresist on the surface of the substrate; providing a mask, wherein the method for forming the mask comprises: providing a target pattern, wherein the target pattern extends along a first direction; dividing the target pattern into a first central area and two first edge areas respectively located on both sides of the first central area; dividing the edge of the target pattern in each of the first edge areas into a number of edges to be compensated; obtaining an etching offset model; performing a first compensation correction on each edge to be compensated according to the etching offset model to obtain a first compensation edge; making a mask using the first compensation edge; using the mask as a mask to expose the photoresist to form a patterned layer; using the patterned layer as a mask to etch the substrate.

[0131] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A method for correcting a target graphic, characterized in that: include: Providing a target pattern, wherein the target pattern extends along a first direction; Dividing the target graphic into a first central area and two first edge areas respectively located on both sides of the first central area; Divide the edge of the target pattern in each of the first edge regions into a plurality of edges to be compensated, and divide the edge of the target pattern in the first edge region into N edges to be compensated along the first direction; Acquire an etching offset model, wherein the etching offset model is suitable for compensating for an etching load effect caused by inconsistent pattern density; Perform a first compensation correction on each edge to be compensated according to the etching offset model to obtain a first compensation edge; When the size of the target pattern along the first direction is greater than a preset value, the etching offset model includes: a first correction model and a second correction model, the first correction model is used to compensate and correct the first edge to be compensated in the first edge region, and the second correction model is used to compensate and correct the xth segment of the edge to be compensated in the first edge region; When the size of the target graphic along the first direction is smaller than a preset value, the etching offset model includes: a third correction model, a fourth correction model and a fifth correction model; the third correction model is used to compensate for the edge of the target graphic in the first central area, the fourth correction model is used to compensate for the first edge to be compensated in the first edge area, and the fifth correction model is used to compensate for the xth segment of the edge to be compensated in the first edge area; wherein x is a natural number greater than or equal to 2 and less than or equal to N.

2. The target graphics correction method according to claim 1, characterized in that: When the size of the target graphic along the first direction is greater than a preset value, the method for dividing the target graphic into a first central area and two first edge areas comprises: obtaining the size l of the target graphic in the first direction long ; Obtain a first central area in the target graphic, the size of the first central area along the first direction is l1, and l1 is greater than or equal to the minimum segmentation value l min ; Obtain a first edge region in the target graphic, the size of the first edge region along the first direction is l0, and satisfies l0=(l long -l1) / 2.

3. The target graphics correction method according to claim 2, characterized in that: The method of dividing the edge of each target pattern in the first edge area into a plurality of edges to be compensated comprises: dividing the edge of the target pattern in the first edge area into N edges to be compensated along the first direction, and N is l long / l min An integer value; obtaining a first edge to be compensated from the plurality of edges to be compensated, the first edge to be compensated being the edge to be compensated that is farthest from the first central area in the first direction, and the size of the first edge to be compensated is l0-(N-1)l min The sizes of the (N-1) edges to be compensated other than the first edge to be compensated are all the minimum segmentation value l min .

4. The target graphics correction method according to claim 3, characterized in that: The etching offset model includes: a first correction model and a second correction model; the method for obtaining the etching offset model includes: providing a second test pattern, the size of which is greater than a preset value in the first direction; using the second test pattern as a mask, performing an exposure process, a development process and an etching process to obtain a second etching pattern; dividing the second etching pattern into a second central area and two second edge areas respectively located on both sides of the first central area, and the size of the second edge area is l0; dividing each second edge area into a plurality of segmented patterns along the first direction, among which the segmented pattern farthest from the second central area is the first segmented pattern, and the size of the first segmented pattern along the first direction is l0-(N-1)l min ; Measure the size CD of the first segmentation pattern AEI_end ; Get the second characteristic size CD AEI ;According to CD AEI_end and CD AEI , and obtain the first revised model for, =CD AEI_end - CD AEI ； According to the first revised model , and obtain the second revised model for, ； And 2≤x≤N, N is a natural number greater than or equal to 2; the second edge area is divided into a plurality of segmentation patterns along the first direction.

5. The target graphics correction method according to claim 4, characterized in that: The first compensation correction method includes: compensating and correcting the first side to be compensated in each first edge zone according to a first correction model; compensating and correcting the xth side to be compensated in the first edge zone according to a second correction model, and 2≤x≤N, N is a natural number greater than or equal to 2.

6. The target graphics correction method according to claim 1, characterized in that: When the size of the target graphic along the first direction is smaller than a preset value, the method for dividing the target graphic into a first central area and two first edge areas comprises: obtaining the size l of the target graphic in the first direction; short ; Obtain a first central area in the target graphic, the size of the first central area along the first direction is l3, and l3 is equal to the minimum segmentation value l min ; Obtain a first edge region in the target graphic, the size of the first edge region along the first direction is l2, and satisfies l2=(l short -l3) / 2.

7. The target pattern correction method according to claim 6, characterized in that: The method of dividing the edge of the target pattern in each first edge area into a plurality of edges to be compensated comprises: dividing the edge of the target pattern in the first edge area into N edges to be compensated along the first direction, and N is l short / l min An integer value; obtaining a first edge to be compensated from the plurality of edges to be compensated, the first edge to be compensated being the edge to be compensated that is farthest from the first central area in the first direction, and the size of the first edge to be compensated is l2-(N-1)l min The sizes of the (N-1) edges to be compensated other than the first edge to be compensated are all the minimum segmentation value l min .

8. The target pattern correction method according to claim 7, characterized in that: The etching offset model includes: a third correction model, a fourth correction model and a fifth correction model; the method for obtaining the etching offset model includes: providing a third test pattern, the size of which in the first direction is smaller than a preset value; using the third test pattern as a mask, performing an exposure process, a development process and an etching process to obtain a third etching pattern; dividing the third etching pattern into a third central area and two third edge areas located on both sides of the third central area, and the size of the third edge area is l2; dividing each of the third etching patterns into a plurality of segmented patterns, among which the segmented pattern farthest from the third central area is a first segmented pattern, and the size of the first segmented pattern along the first direction is l2-(N-1)l min ; Measure the size CD of the first segmentation pattern AEI_end_short ; Measure the size CD of the third etching pattern in the third central area AEI_short ; Get CD AEI ;According to CD AEI_end_short and CD AEI_short , and CD AEI , and obtain the third revised model for, =CD AEI_short -CD AEI ; According to the third revised model , and obtain the fourth revised model for, =CD AEI_end_short -CD AEI_short + ; According to the third revised model and the fourth revised model , and get the fifth revised model for, ； And 2≤x≤N, N is a natural number greater than or equal to 2; the third etching pattern is divided into a plurality of divided patterns.

9. The target graphic correction method according to claim 8, characterized in that: The first compensation correction also includes: compensating and correcting the edge of the target figure in the first central area; the second compensation correction method includes: compensating and correcting the edge of the target figure in the first central area according to the third correction model; compensating and correcting the first side to be compensated in each first edge area according to the fourth correction model; compensating and correcting the xth side to be compensated in each first edge area according to the fifth correction model, and 2≤x≤N, N is a natural number greater than or equal to 2.

10. The target pattern correction method according to claim 4, characterized in that: The CD AEI The method for obtaining the first test pattern includes: providing a first test pattern; using a mask plate made of the first test pattern as a mask, performing an exposure process and a development process to obtain a first photolithography pattern; using the first photolithography pattern as a mask, performing an etching process to obtain a first etching pattern; measuring and obtaining a second characteristic dimension CD of the first etching pattern AEI .

11. The target graphic correction method according to claim 10, characterized in that: The method also includes: measuring and obtaining a first characteristic size CD of the first photolithography pattern ADI ; The method for obtaining the target pattern includes: measuring the first characteristic size CD of the first photolithography pattern ADI According to the first characteristic size CD ADI and the second characteristic size CD AEI The difference between the two is used to obtain the compensation value. etching bias =CD ADI -CD AEI ; Provide an initial target graph; According to the compensation value etching bias , performing a second compensation correction on the initial target graphic to obtain the target graphic.

12. The target pattern correction method according to claim 8, characterized in that: The CD AEI The method for obtaining the first test pattern includes: providing a first test pattern; using a mask plate made of the first test pattern as a mask, performing an exposure process and a development process to obtain a first photolithography pattern; using the first photolithography pattern as a mask, performing an etching process to obtain a first etching pattern; measuring and obtaining a second characteristic dimension CD of the first etching pattern AEI .

13. The target pattern correction method according to claim 12, characterized in that: The method also includes: measuring and obtaining a first characteristic size CD of the first photolithography pattern ADI ; The method for obtaining the target pattern includes: measuring the first characteristic size CD of the first photolithography pattern ADI According to the first characteristic size CD ADI and the second characteristic size CD AEI The difference between the two is used to obtain the compensation value. etching bias =CD ADI -CD AEI ; Provide an initial target graph; According to the compensation value etching bias , performing a second compensation correction on the initial target graphic to obtain the target graphic.

14. The target graphic correction method according to claim 2, characterized in that: The preset value ranges from 700 nanometers to 1500 nanometers.

15. A method for making a mask, characterized in that: include: Providing a target pattern, wherein the target pattern extends along a first direction; Dividing the target graphic into a first central area and two first edge areas respectively located on both sides of the first central area; Divide the edge of the target pattern in each of the first edge regions into a plurality of edges to be compensated, and divide the edge of the target pattern in the first edge region into N edges to be compensated along the first direction; Acquire an etching offset model, wherein the etching offset model is suitable for compensating for an etching load effect caused by inconsistent pattern density; Perform a first compensation correction on each edge to be compensated according to the etching offset model to obtain a first compensation edge; Making a mask using the first compensation edge; When the size of the target pattern along the first direction is greater than a preset value, the etching offset model includes: a first correction model and a second correction model, the first correction model is used to compensate and correct the first edge to be compensated in the first edge region, and the second correction model is used to compensate and correct the xth segment of the edge to be compensated in the first edge region; When the size of the target pattern along the first direction is smaller than a preset value, the etching offset model includes: a third correction model, a fourth correction model and a fifth correction model; the third correction model is used to compensate and correct the edge of the target pattern in the first central area, the fourth correction model is used to compensate and correct the first edge to be compensated in the first edge area, and the fifth correction model is used to compensate and correct the xth segment of the edge to be compensated in the first edge area; Wherein x is a natural number greater than or equal to 2 and less than or equal to N.

16. A method for forming a semiconductor structure, characterized in that: include: providing a substrate; forming a photoresist on the surface of the substrate; A mask is provided, and a method for forming the mask includes: providing a target pattern, wherein the target pattern extends along a first direction; dividing the target pattern into a first central area and two first edge areas respectively located on both sides of the first central area; dividing the edge of the target pattern in each of the first edge areas into a plurality of edges to be compensated, and dividing the edge of the target pattern in the first edge area into N edges to be compensated along the first direction; obtaining an etching offset model, wherein the etching offset model is suitable for compensating for an etching load effect caused by inconsistent pattern density; performing a first compensation correction on each edge to be compensated according to the etching offset model to obtain a first compensation edge; Making a mask using the first compensation edge; Using the mask plate as a mask, exposing the photoresist to form a patterned layer; Using the patterned layer as a mask, etching the substrate; When the size of the target pattern along the first direction is greater than a preset value, the etching offset model includes: a first correction model and a second correction model, the first correction model is used to compensate and correct the first edge to be compensated in the first edge region, and the second correction model is used to compensate and correct the xth segment of the edge to be compensated in the first edge region; When the size of the target pattern along the first direction is smaller than a preset value, the etching offset model includes: a third correction model, a fourth correction model and a fifth correction model; the third correction model is used to compensate and correct the edge of the target pattern in the first central area, the fourth correction model is used to compensate and correct the first edge to be compensated in the first edge area, and the fifth correction model is used to compensate and correct the xth segment of the edge to be compensated in the first edge area; Wherein x is a natural number greater than or equal to 2 and less than or equal to N.

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