A method for manufacturing a chip

Abstract

An embodiment of the present application discloses a method for manufacturing a chip. The method includes: providing a photomask; dividing a first surface of the photomask into a plurality of preset regions with the same size and shape; obtaining the pattern density of each preset region among the plurality of preset regions according to the number of preset patterns in each preset region; obtaining a correction region according to the pattern density of the preset region, where the correction region includes at least one preset region with a pattern density value range between a first preset value and a second preset value, including the endpoint values; selecting a plurality of measurement points in the correction region, and adjusting the exposure dose when manufacturing the chip using the photomask according to the line width of the preset pattern at the positions where the plurality of measurement points are located; manufacturing the chip using the photomask according to the adjusted exposure dose, which can effectively improve the uniformity of the chip line width, thereby helping to improve the yield of the chip.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and particularly to a method for manufacturing a chip. Background Art

[0002] With the development of semiconductor technology and the requirements of industrial production, the size of semiconductor devices is constantly shrinking. The reduction in the size of semiconductor devices will inevitably lead to a continuous decrease in the critical dimension (CD) of the chip.

[0003] However, as the critical dimension of the chip continues to decrease, it becomes more difficult to control the critical dimension of the chip during chip manufacturing, which affects the critical dimension uniformity (CDU) of the chip, resulting in poor critical dimension uniformity of the chip, and thus affecting the yield of the chip. Therefore, in order to effectively avoid the influence of the critical dimension uniformity of the chip on the chip yield, providing a chip manufacturing method that can help improve the critical dimension uniformity of the chip has become the research focus of those skilled in the art. Summary of the Invention

[0004] To solve the above technical problems, an embodiment of this application provides a method for manufacturing a chip, which can help improve the critical dimension uniformity and thus help improve the yield of the chip.

[0005] To solve the above problems, the embodiment of this application provides the following technical solutions:

[0006] A method for manufacturing a chip, the method comprising:

[0007] Providing a photomask, wherein a first surface of the photomask has a plurality of preset patterns;

[0008] Dividing the first surface of the photomask into a plurality of preset regions having the same size and shape;

[0009] Obtaining the pattern density of each preset region in the plurality of preset regions according to the number of preset patterns in each preset region;

[0010] Obtaining a correction region according to the pattern density of each preset region in the plurality of preset regions, the correction region including at least one preset region whose pattern density value range is between a first preset value and a second preset value, including the end point values;

[0011] Selecting a plurality of measurement points in the correction region, the plurality of measurement points being located on the preset patterns in the correction region, and adjusting the exposure dose when manufacturing a chip using the photomask according to the line width of the preset patterns at the positions where the plurality of measurement points are located;

[0012] Fabricate a chip using the photomask according to the adjusted exposure dose.

[0013] Optionally, obtaining the correction region according to the pattern density of each preset region in the multiple preset regions includes:

[0014] Obtain the pattern density curve of the photomask according to the pattern density of each preset region in the multiple preset regions;

[0015] Obtain the first preset value and the second preset value according to the pattern density curve;

[0016] Obtain the correction region according to the first preset value and the second preset value.

[0017] Optionally, the correction region includes at least one preset region, and selecting multiple measurement points in the correction region includes:

[0018] Select multiple measurement points in at least one preset region in the correction region;

[0019] Wherein, selecting multiple measurement points in at least one preset region in the correction region includes:

[0020] Select multiple measurement points in the first direction and the second direction of at least one preset region in the correction region;

[0021] The first direction and the second direction are parallel to the first surface of the photomask, and the first direction is perpendicular to the second direction.

[0022] Optionally, the correction region includes multiple preset regions, and selecting multiple measurement points in the correction region includes:

[0023] Select multiple measurement points in each preset region in the correction region;

[0024] Wherein, selecting multiple measurement points in each preset region in the correction region includes:

[0025] Select multiple measurement points in the first direction and the second direction of each preset region in the correction region;

[0026] The first direction and the second direction are parallel to the first surface of the photomask, and the first direction is perpendicular to the second direction.

[0027] Optionally, adjusting the exposure dose when fabricating a chip using the photomask according to the line width of the preset pattern at the positions where the multiple measurement points are located includes:

[0028] Obtain the line width at the positions where the multiple measurement points are located;

[0029] Compare the line width of the preset pattern at the positions of the multiple measurement points with the preset line width of the chip to obtain the difference between the line width of the preset pattern at the positions of the multiple measurement points and the preset line width of the chip;

[0030] Adjust the exposure dose when manufacturing the chip using the photomask according to the difference;

[0031] Wherein, the preset line width of the chip is the ideal value of the chip line width.

[0032] Optionally, adjusting the exposure dose when manufacturing the chip using the photomask according to the difference includes:

[0033] When the difference between the line width of the preset pattern at the position of the measurement point and the preset line width of the chip is less than the third preset value, when manufacturing the chip using the photomask, increase the exposure dose at the position corresponding to the chip wafer at the position of the measurement point;

[0034] When the difference between the line width of the preset pattern at the position of the measurement point and the preset line width of the chip is greater than the fourth preset value, when manufacturing the chip using the photomask, decrease the exposure dose at the position corresponding to the chip wafer at the position of the measurement point;

[0035] When the value range of the difference between the line width of the preset pattern at the position of the measurement point and the preset line width of the chip is between the third preset value and the fourth preset value, including the endpoint values, when manufacturing the chip using the photomask, do not change the exposure dose at the position corresponding to the chip wafer at the position of the measurement point.

[0036] Compared with the prior art, the above technical solution has the following advantages:

[0037] The technical solution provided by the embodiments of the present application includes: providing a photomask, wherein a first surface of the photomask has a plurality of preset patterns; dividing the first surface of the photomask into a plurality of preset regions with the same size and shape; obtaining the pattern density of each of the plurality of preset regions; obtaining a correction region according to the pattern density of the preset region, the correction region including at least one of the preset regions whose pattern density value range is between a first preset value and a second preset value, including the endpoint values; selecting a plurality of measurement points in the correction region, and adjusting the exposure dose when manufacturing a chip using the photomask according to the line width of the preset pattern at the positions where the plurality of measurement points are located; manufacturing the chip using the photomask according to the adjusted exposure dose. As can be seen from the above, the method provided by the embodiments of the present application obtains a correction region according to the pattern density of a plurality of preset regions on the first surface of the photomask, and then selects a plurality of measurement points in the correction region. It is known that the pattern density value range of the correction region is between a first preset value and a second preset value, including the endpoint values, which can avoid the pattern density in the correction region being too large or too small, and further avoid the line width at the positions of the plurality of measurement points selected in the correction region being too large or too small, so that the line width at the positions of the selected measurement points can more truly reflect the actual line width distribution of the photomask. Therefore, when adjusting the exposure dose according to the line width at the positions of the measurement points, it is helpful to accurately adjust the exposure dose, so that the line width uniformity of the chip manufactured according to the adjusted exposure dose is better, which is helpful to improve the line width uniformity of the chip, and further helpful to improve the yield of the chip. Description of the Drawings

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0039] Figure 1 It is a relationship curve between the line width at the position of the measurement point on the preset pattern in the photomask and the pattern density of the photomask;

[0040] Figure 2 It is a flowchart of a method for manufacturing a chip provided by an embodiment of the present application;

[0041] Figure 3 It is a top view of a photomask in a method for manufacturing a chip provided by an embodiment of the present application;

[0042] Figure 4 It is a comparison chart of chip line width distribution curves obtained by different chip manufacturing methods;

[0043] Figure 5 The photomask pattern density distribution curve in a method for manufacturing a chip provided by an embodiment of the present application;

[0044] Figure 6 The pattern density distribution diagrams of multiple preset regions of the photomask in a method for manufacturing a chip provided by an embodiment of the present application. Detailed implementation manners

[0045] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0046] In the following description, many specific details are set forth in order to fully understand the present application. However, the present application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0047] Secondly, the present application will be described in detail in conjunction with the schematic diagrams. When describing the embodiments of the present application in detail, for the convenience of explanation, the cross-sectional views showing the device structure will be enlarged locally out of the general scale, and the schematic diagrams are only examples and should not limit the protection scope of the present application herein. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0048] As described in the background art section, in order to effectively avoid the influence of the chip line width uniformity on the chip yield, providing a chip manufacturing method that can help improve the chip line width uniformity has become the research focus of those skilled in the art.

[0049] As the size of semiconductor devices continues to decrease, in order to ensure the chip yield, the control of the chip line width uniformity becomes increasingly important.

[0050] Generally, when manufacturing a chip, in order to improve the line width uniformity of the manufactured chip, multiple measurement points are usually selected on the photomask, and the line widths at the positions of the multiple measurement points are obtained. According to the line widths at the positions of the multiple measurement points on the photomask, the deviation between the line widths at the positions of the multiple measurement points on the photomask and the ideal line width of the chip is obtained. According to the deviation between the line widths at the positions of the multiple measurement points on the photomask and the ideal line width of the chip, the compensation value of the exposure dose when manufacturing the chip according to the photomask is obtained, and the exposure dose when manufacturing the chip is adjusted as accurately as possible. Then, according to the adjusted exposure dose, the pattern on the photomask is transferred to the wafer to form a chip, so as to improve the line width uniformity of the chip.

[0051] In order to improve the line width uniformity of the chip, the existing chip manufacturing method usually corrects the chip line width. The manufacturing method includes: providing a mask with a preset pattern on the mask; randomly selecting multiple measurement points on the mask, generally randomly selecting 64 to 200 measurement points, obtaining the line widths at the locations of the selected multiple measurement points, and comparing the line widths at the locations of the multiple measurement points with the ideal line width of the chip to obtain the deviation between the line widths at the locations of the multiple measurement points on the mask and the ideal line width of the chip. The line widths at the locations of the multiple measurement points on the mask will represent the average line width of the pattern around the multiple measurement points on the mask, thereby serving as a standard for measuring the line width distribution of the mask. Then, according to the deviation between the line widths at the locations of the multiple measurement points on the mask and the ideal line width of the chip, the distribution of the compensation value of the exposure dose on the surface of the wafer on which the chip is to be formed is obtained, and the exposure dose when the chip is manufactured using the mask is adjusted according to the compensation value. Then, according to the adjusted exposure dose, the preset pattern on the mask is transferred to the wafer to form a chip through a photolithography process to improve the line width uniformity of the chip. It should be noted that when manufacturing a chip, it is necessary to transfer the preset pattern on the mask to the wafer through a photolithography process, so that the preset pattern on the mask corresponds to the pattern on the formed chip.

[0052] However, according to the above, the existing chip manufacturing method selects the measurement points on the mask randomly. Figure 1 As shown, the mask surface has multiple preset patterns, and the pattern density (PD) of different areas on the mask is also different, which will make the line width of the area with high pattern density smaller and the line width of the area with low pattern density larger. The existing chip manufacturing method randomly selects the measurement points on the mask, and does not take into account the influence of the pattern density on the line width of the position where the measurement point of the mask is located. As a result, when obtaining the line width of the position where the measurement point of the mask is located, if the selected measurement point is located in an area with high pattern density, the line width at the position where the measurement point is located will be smaller, and if the selected measurement point is located in an area with low pattern density, the line width at the position where the measurement point is located will be larger, which cannot reflect the actual line width distribution of the mask, and thus cannot correctly adjust the exposure dose, and cannot ensure the accuracy of the exposure dose when the pattern on the mask is transferred to the wafer to form a chip, which affects the line width uniformity of the chip and further affects the yield of the chip.

[0053] Based on this, the present application embodiment provides a method for manufacturing a chip, such as Figure 2 As shown, the method comprises the following steps:

[0054] S1: Figure 3 As shown, a light mask 10 is provided, and a first surface of the light mask 10 has a plurality of preset patterns 11;

[0055] S2: Continue as Figure 3 shown, divide the first surface of the photomask 10 into a plurality of preset regions 12 with the same size and shape;

[0056] S3: According to the number of the preset patterns 11 in each of the plurality of preset regions 12, obtain the pattern density of each of the plurality of preset regions 12;

[0057] S4: According to the pattern density of each of the plurality of preset regions 12, obtain a correction region 13, where the correction region 13 includes at least one of the preset regions 12 whose pattern density value range is between a first preset value and a second preset value, including the endpoint values;

[0058] S5: Select a plurality of measurement points in the correction region 13. The plurality of measurement points are located on the preset patterns in the correction region. Adjust the exposure dose when manufacturing a chip using the photomask according to the line width of the preset patterns at the positions where the plurality of measurement points are located. It should be noted that the line width of the preset patterns at the positions where the plurality of measurement points are located is the line width of the graphic lines corresponding to the positions where the measurement points are located on the preset patterns, not the line width of the entire preset pattern, nor the overall width of the preset pattern where the measurement points are located.

[0059] S6: Manufacture a chip using the photomask according to the adjusted exposure dose.

[0060] It should be noted that the line width of the photomask has a crucial impact on the line width uniformity of the chip. In order to improve the line width uniformity of the chip, it is necessary to select a plurality of measurement points on the photomask, obtain the line width of the preset patterns at the positions of the plurality of measurement points on the photomask, and correct the line width of the chip according to the line width of the preset patterns at the positions of the plurality of measurement points on the photomask, so as to improve the line width uniformity of the chip. Among them, the line width of the preset patterns at the positions of the measurement points of the obtained photomask is related to the pattern density of the area where the measurement points of the photomask are located. The greater the pattern density, the smaller the line width of the preset patterns at the positions of the measurement points of the photomask. Conversely, the larger the line width of the preset patterns at the positions of the measurement points of the photomask. If the pattern density of the area where the selected measurement points are located is not moderate, the line width of the preset patterns at the positions of the measurement points cannot accurately reflect the line width of the photomask, and thus the exposure dose when manufacturing a chip using the photomask cannot be accurately adjusted, which will affect the line width uniformity of the chip when manufacturing a chip using the photomask.

[0061] In the embodiment of the present application, the manufacturing method obtains a correction area according to the pattern density of a plurality of preset areas on the first surface of the photomask, and then selects a plurality of measurement points in the correction area. It is known that the pattern density value range of the correction area is between a first preset value and a second preset value, including the end point values, which can avoid the pattern density in the correction area being too large or too small, and further avoid the line width of the preset pattern at the positions of the plurality of measurement points selected in the correction area being too large or too small, so that the line width of the preset pattern at the positions of the selected measurement points can more truly reflect the actual line width distribution of the photomask. Therefore, when adjusting the exposure dose according to the line width of the preset pattern at the position of the measurement point, it helps to accurately adjust the exposure dose. According to the adjusted exposure dose, the line width uniformity of the manufactured chip is better, which helps to improve the line width uniformity of the chip, and further helps to improve the yield of the chip.

[0062] Specifically, as Figure 4 shown, Figure 4 is a comparison chart of chip line width distribution curves. In the figure, line 1 is the chip line width distribution curve obtained by using the manufacturing method provided in the embodiment of the present application, line 2 is the chip line width distribution curve obtained by using the aforementioned existing chip manufacturing method, and line 3 is the chip line width distribution curve obtained by the chip manufacturing method without adjusting the exposure dose. According to Figure 4 the line width distribution curves of each, it can be seen that the width of the chip line width distribution curve obtained by using the method provided in the embodiment of the present application is the narrowest, the width of the chip line width distribution curve obtained by using the aforementioned chip manufacturing method is the second, and the chip line width distribution curve obtained by the chip manufacturing method without adjusting the exposure dose is the widest. Therefore, the difference in the chip line width obtained by using the method provided in the embodiment of the present application is smaller, that is, the line width uniformity is the best, indicating that using the method provided in the embodiment of the present application to manufacture chips can effectively improve the line width uniformity of the chips and help to improve the yield of the chips.

[0063] It should be noted that in the embodiment of the present application, the software program installed on a certain hardware scans the surface of the photomask, divides the surface of the photomask into a plurality of preset areas with the same size and shape, and obtains the pattern density of the plurality of preset areas according to the number of preset patterns in each preset area. This process will not be described in detail here.

[0064] Based on the above embodiments, in an embodiment of the present application, obtaining the correction area according to the pattern density of each preset area in the plurality of preset areas includes: obtaining the pattern density curve of the photomask according to the pattern density of each preset area in the plurality of preset areas; obtaining the first preset value and the second preset value according to the pattern density curve of the photomask, that is, obtaining the pattern density value with moderate pattern density on the first surface of the photomask according to the pattern density curve, where the first preset value is less than the second preset value. Generally, the first preset value and the second preset value are respectively located on both sides of the highest point of the pattern density curve, and the difference between the pattern density value corresponding to the first preset value and the pattern density value corresponding to the highest point of the pattern density curve is not greater than 10%, and the difference between the pattern density value corresponding to the second preset value and the pattern density value corresponding to the highest point of the pattern density curve is not greater than 10%, so that the first preset value and the second preset value can be obtained according to the pattern density curve of the photomask; obtaining the correction area according to the first preset value and the second preset value can effectively prevent the pattern density of the correction area from being too large or too small, thereby preventing the line width of the correction area from being too small or too large, which helps to accurately adjust the exposure dose when manufacturing a chip using the photomask, can effectively improve the line width uniformity of the chip, and thus helps to improve the yield of the chip. It should be noted that when determining the correction area on the photomask, according to the different pattern characteristics of the chips produced by the chip factory, the suitable value of the pattern density of the correction area is different and needs to be determined according to the actual situation of the chip. However, currently, it is generally considered that the area where the pattern density is between 10% less than the density value corresponding to the highest point of the pattern density curve and 10% greater than the density value corresponding to the highest point of the pattern density curve is suitable as the correction area, but the present application does not limit this, and it depends on the specific situation.

[0065] Specifically, as Figure 5 shown, Figure 5It is the graphic density distribution curve of the first surface of the photomask in the method provided by the embodiment of the present application. Herein, the abscissa is the graphic density, and the ordinate is the number of preset regions corresponding to each graphic density. The value of the graphic density corresponding to A is the first preset value, and the value of the graphic density corresponding to B is the second preset value. The preset region with a graphic density less than the first preset value is the region with too small graphic density, the preset region with a graphic density greater than the second preset value is the region with too large graphic density, and the preset region with a graphic density between the first preset value and the second preset value is the region with moderate graphic density, including the endpoint values, which is the correction region. Through the graphic density distribution curve, the regions with too large and too small graphic densities can be excluded, and the measurement points are only selected in the correction region with moderate graphic density, so that the line widths of the selected measurement points can truly reflect the line width distribution of the photomask, thereby helping to improve the line width uniformity of the chip manufactured by the manufacturing method, and further helping to improve the yield of the chip.

[0066] And, as Figure 6 shown, Figure 6 in the figure, region C is the correction region where the value range of the graphic density is between the first preset value and the second preset value, and region D and region E are respectively the preset region with a graphic density less than the first preset value and the preset region with a graphic density greater than the second preset value. When correcting the chip line width, the measurement points are selected in the correction region where the value range of the graphic density is between the first preset value and the second preset value, and the measurement points are not selected in the preset region D with a graphic density less than the first preset value and the preset region E with a graphic density greater than the second preset value, so as to avoid the influence of the graphic density of the region where the selected measurement points are located on the line width of the position where the measurement points are located. It should be noted that in other embodiments of the present application, the value range of the graphic density of the correction region may also be other values, and the present application does not limit this, which depends on the specific situation.

[0067] On the basis of the above embodiments, in an embodiment of the present application, selecting multiple measurement points in the correction region includes: selecting multiple measurement points in at least one preset region in the correction region; wherein, selecting multiple measurement points in at least one preset region in the correction region includes: selecting multiple measurement points in the first direction and the second direction of at least one preset region in the correction region, the first direction and the second direction are parallel to the first side surface of the photomask, and the first direction is perpendicular to the second direction, so that the selected measurement points can reflect the line width distribution of the photomask as diversely as possible, so that the measurement points selected in at least one preset region in the correction region can reflect the line width distribution of the photomask as much as possible, which helps to adjust the exposure dose when manufacturing a chip using the photomask, improve the line width uniformity of the chip, and improve the yield of the chip.

[0068] In another embodiment of the present application, the correction region includes a plurality of preset regions. Selecting a plurality of measurement points in the correction region includes: selecting a plurality of measurement points in each of the preset regions in the correction region; wherein, selecting a plurality of measurement points in each of the preset regions in the correction region includes: selecting a plurality of measurement points in the first direction and the second direction of each of the preset regions in the correction region, wherein the first direction and the second direction are parallel to the first side surface of the photomask, and the first direction is perpendicular to the second direction, so that the selected measurement points can reflect the line width distribution of the photomask as diversely as possible, so that the measurement points selected in at least one preset region in the correction region can reflect the line width distribution of the photomask as much as possible, which helps to adjust the exposure dose when manufacturing a chip using the photomask, improve the line width uniformity of the chip, and increase the yield of the chip. It should be noted that when the correction region includes a plurality of preset regions and a plurality of measurement points are selected in the correction region, a plurality of measurement points may also be selected in at least one of the plurality of preset regions in the correction region. The present application does not limit this and it depends on the specific situation.

[0069] Based on any of the above embodiments, in an embodiment of the present application, adjusting the exposure dose when manufacturing a chip using the photomask according to the line widths of the preset patterns at the positions of the plurality of measurement points includes: selecting a plurality of measurement points in the correction region, and obtaining the line widths of the preset patterns at the positions of the plurality of measurement points; according to the line widths of the preset patterns at the positions of the plurality of measurement points, comparing the line widths of the preset patterns at the positions of the plurality of measurement points with the preset line width of the chip to obtain the difference between the line widths of the preset patterns at the positions of the plurality of measurement points and the preset line width of the chip, wherein the preset line width of the chip is the ideal value of the chip line width; according to the difference, that is, the difference between the line widths of the preset patterns at the positions of the plurality of measurement points and the preset line width of the chip, obtaining the distribution of the compensation value of the exposure dose when manufacturing a chip using the photomask on the wafer surface to adjust the exposure dose when manufacturing a chip using the photomask. Since the exposure dose has an important influence on the line width when transferring the preset pattern on the photomask to the wafer to manufacture a chip, the method can correctly adjust the exposure dose when manufacturing a chip using the photomask by using the difference between the line widths of the preset patterns at the positions of the plurality of measurement points and the preset line width of the chip, which helps to improve the line width uniformity of the chip manufactured by the manufacturing method, and thus helps to improve the line width uniformity of the chip and increase the yield of the chip.

[0070] Based on the above embodiments, in an embodiment of the present application, whether it is for the embodiment of selecting multiple measurement points in at least one of the preset regions in the correction region or for the embodiment of selecting multiple measurement points in each preset region in the correction region, adjusting the exposure dose when manufacturing the chip using the photomask according to the difference, that is, the difference between the line width at the positions of the multiple measurement points and the preset line width of the chip, includes: when the difference between the line width of the preset pattern at the position of the measurement point and the preset line width of the chip is less than a third preset value, that is, when the preset line width of the chip is greater than the line width of the preset pattern at the position of the measurement point, and the difference between the line width of the preset pattern at the position of the measurement point and the preset line width of the chip exceeds the allowable range, in order to improve the uniformity of the chip line width when transferring the pattern on the photomask to the wafer to form the chip, when manufacturing the chip using the photomask, increase the exposure dose at the position corresponding to the measurement point on the chip wafer, that is, the compensation value of the exposure dose at the position corresponding to the measurement point on the wafer is greater than 0;

[0071] When the difference between the line width of the preset pattern at the position of the measurement point and the preset line width of the chip is greater than a fourth preset value, that is, when the preset line width of the chip is less than the line width of the preset pattern at the position of the measurement point, and the difference between the line width of the preset pattern at the position of the measurement point and the preset line width of the chip exceeds the allowable range, in order to improve the uniformity of the chip line width when transferring the pattern on the photomask to the wafer to form the chip, when manufacturing the chip using the photomask, decrease the exposure dose at the position corresponding to the measurement point on the chip wafer, that is, the compensation value of the exposure dose at the position corresponding to the measurement point is less than 0;

[0072] When the difference between the line width of the preset pattern at the position of the measurement point and the preset line width of the chip is between the third preset value and the fourth preset value, including the endpoint values, that is, when the difference between the line width of the preset pattern at the position of the measurement point and the preset line width of the chip is within the allowable range, when manufacturing the chip using the photomask, do not change the exposure dose at the position corresponding to the measurement point on the chip wafer, that is, the compensation value of the exposure dose is equal to 0, and the exposure dose remains unchanged.

[0073] It should be noted that when manufacturing the chip using the photomask, the pattern of the photomask is transferred to the chip through a lithography process. The preset pattern on the photomask corresponds to the pattern formed on the chip, and the line width of the preset pattern at the position of the measurement point represents the line width of the area around the measurement point. Thus, the exposure dose adjusted according to the line width of the preset pattern at the position of the measurement point can represent the exposure dose of the area around the position corresponding to the chip wafer and the measurement point, so that the adjustment of the exposure dose during chip manufacturing can be achieved. Moreover, when transferring the pattern on the photomask to the wafer to form a chip, the pattern on the photomask needs to be projected onto the wafer. Therefore, when manufacturing the chip using the photomask, by changing the exposure dose at the position corresponding to the chip wafer and the position of the measurement point on the photomask, the adjustment of the exposure dose during chip manufacturing can be realized, thereby realizing the adjustment of the line width on the chip and improving the line width uniformity of the chip. It should also be noted that the specific values of the third preset value and the fourth preset value in the embodiments of the present application are not limited, which are related to the manufacturing precision requirements of the chip and depend on specific circumstances.

[0074] In summary, the embodiments of the present application provide a method for manufacturing a chip, which includes: providing a photomask, the first surface of which has a plurality of preset patterns; dividing the first surface of the photomask into a plurality of preset regions with the same size and shape; obtaining the pattern density of each of the plurality of preset regions; according to the pattern density of the preset region, obtaining a correction region, the correction region including at least one of the preset regions with the pattern density value range between a first preset value and a second preset value, including the end point values; selecting a plurality of measurement points in the correction region, and adjusting the exposure dose when manufacturing the chip using the photomask according to the line width of the preset pattern at the positions of the plurality of measurement points; manufacturing the chip using the photomask according to the adjusted exposure dose. As can be seen from the above, the method provided by the embodiments of the present application obtains the correction region according to the pattern density of the plurality of preset regions on the first surface of the photomask, and then selects a plurality of measurement points in the correction region. Since the pattern density value range of the correction region is between the first preset value and the second preset value, including the end point values, it can avoid the pattern density in the correction region being too large or too small, and further avoid the line width at the positions of the plurality of measurement points selected in the correction region being too large or too small, so that the line width at the positions of the selected measurement points can more truly reflect the actual line width distribution of the photomask. Thus, when adjusting the exposure dose according to the line width at the position of the measurement point, it helps to accurately adjust the exposure dose, so that the line width uniformity of the chip manufactured according to the adjusted exposure dose is better, which helps to improve the line width uniformity of the chip, and further helps to improve the yield of the chip.

[0075] In this specification, each part is described in a combined way of parallelism and progression. What each part focuses on explaining are the differences from other parts. For the same or similar parts among the parts, reference can be made to each other.

[0076] Regarding the above description of the disclosed embodiments, the features described in each embodiment in this specification can be replaced or combined with each other, enabling those skilled in the art to implement or use this application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for manufacturing a chip, characterized in that, Including: Providing a photomask, wherein a first surface of the photomask has a plurality of preset patterns; Dividing the first surface of the photomask into a plurality of preset regions with the same size and shape; Obtaining the pattern density of each preset region in the plurality of preset regions according to the number of preset patterns in each preset region; Obtaining a correction region according to the pattern density of each preset region in the plurality of preset regions, including: obtaining a pattern density curve of the photomask according to the pattern density of each preset region in the plurality of preset regions, wherein the abscissa is the pattern density and the ordinate is the number of preset regions corresponding to each pattern density; obtaining a first preset value and a second preset value according to the pattern density curve of the photomask, wherein the first preset value is less than the second preset value, the first preset value and the second preset value are respectively located on both sides of the highest point of the pattern density curve, and the difference between the pattern density value corresponding to the first preset value and the pattern density value corresponding to the highest point of the pattern density curve is not greater than 10%, and the difference between the pattern density value corresponding to the second preset value and the pattern density value corresponding to the highest point of the pattern density curve is not greater than 10%; obtaining the correction region according to the first preset value and the second preset value, and the correction region includes at least one preset region with a pattern density value range between the first preset value and the second preset value, including the end point values; Selecting a plurality of measurement points in the correction region, the plurality of measurement points are located on the preset patterns in the correction region, and adjusting the exposure dose when manufacturing a chip using the photomask according to the line widths of the preset patterns at the positions where the plurality of measurement points are located; Manufacturing a chip using the photomask according to the adjusted exposure dose.

2. The method according to claim 1, characterized in that, The correction region includes at least one preset region, and selecting a plurality of measurement points in the correction region includes: Selecting a plurality of measurement points in at least one preset region in the correction region; Wherein, selecting a plurality of measurement points in at least one preset region in the correction region includes: Selecting a plurality of measurement points in a first direction and a second direction of at least one preset region in the correction region; The first direction and the second direction are parallel to the first surface of the photomask, and the first direction is perpendicular to the second direction.

3. The method according to claim 1, characterized in that, The correction region includes a plurality of preset regions, and selecting a plurality of measurement points in the correction region includes: Selecting a plurality of measurement points in each preset region in the correction region; Wherein, selecting a plurality of measurement points in each preset region in the correction region includes: Selecting a plurality of measurement points in a first direction and a second direction of each preset region in the correction region; The first direction and the second direction are parallel to the first surface of the photomask, and the first direction is perpendicular to the second direction.

4. The method according to claim 1, characterized in that, Adjusting the exposure dose when manufacturing a chip using the photomask according to the line widths of the preset patterns at the positions where the plurality of measurement points are located includes: Obtaining the line widths of the positions where the plurality of measurement points are located; Compare the line width of the preset pattern at the positions of the multiple measurement points with the preset line width of the chip to obtain the difference between the line width of the preset pattern at the positions of the multiple measurement points and the preset line width of the chip; Adjust the exposure dose when manufacturing the chip using the photomask according to the difference; Among them, the preset line width of the chip is the ideal value of the chip line width.

5. The method according to claim 4, characterized in that, Adjusting the exposure dose when manufacturing the chip using the photomask according to the difference includes: When the difference between the line width of the preset pattern at the position of the measurement point and the preset line width of the chip is less than the third preset value, when manufacturing the chip using the photomask, increase the exposure dose at the position corresponding to the chip wafer at the position of the measurement point; When the difference between the line width of the preset pattern at the position of the measurement point and the preset line width of the chip is greater than the fourth preset value, when manufacturing the chip using the photomask, reduce the exposure dose at the position corresponding to the chip wafer at the position of the measurement point; When the value range of the difference between the line width of the preset pattern at the position of the measurement point and the preset line width of the chip is between the third preset value and the fourth preset value, including the endpoint values, when manufacturing the chip using the photomask, do not change the exposure dose at the position corresponding to the chip wafer at the position of the measurement point.

Images