A photolithography verification layout and photomask

Abstract

The application discloses a photolithography verification layout and a photolithography plate. The photolithography verification layout comprises a plurality of plate alignment marks, more than one set of mutual offset marks and a plurality of groups of CD resolution marks. The plurality of plate alignment marks are located in the peripheral non-graphic area of the photolithography plate and correspond to different types of photolithography machines. The mutual offset marks are located in the graphic area of the photolithography plate. The plurality of groups of CD resolution marks are located in the graphic area of the photolithography plate. The application can realize matching and correction of a plurality of different types of photolithography machines.

Description

TECHNICAL FIELD

[0001] The present application mainly relates to the field of photoetching technology, and in particular to a photoetching verification layout and a photoetching plate. BACKGROUND

[0002] In matching different models of photoetching machines (such as i12 and DUV204), due to the difference in the use of photoetching plates, the test plate provided by the machine cannot realize the matching of different models of machines, and there is a certain technical defect:

[0003] 1. The original photoetching plate only has a set of model photoetching plate alignment marks, and the alignment marks used by different models of exposure machines are different, and cannot be used across models. For example, the plate alignment mark of i12 cannot be read on DUV.

[0004] 2. The test layout of different models of photoetching machines is different, and the exposed patterns are different, and the multi-layer patterns cannot be aligned, and the offset cannot be calculated.

[0005] In addition, in the process of semiconductor manufacturing photoetching, the exposure of the first layer is not aligned with the mark of the previous layer, and blind exposure is used. The blind exposure result has a great influence on the subsequent coarse alignment. If the initial position of blind exposure is not uniform in batch production, the next layer of exposure machine may have difficulty in alignment during the alignment process, which seriously affects the operation efficiency.

[0006] To solve the above problems, the existing solutions are as follows: when the first layer is blind exposed, select a device with very stable wafer Pre-alignment Repeatability (calculate the dispersion of X, Y and θ directions respectively) as the first layer. Use the test plate provided by the device manufacturer to calibrate the Alignment Accuracy of the device. This method can select the same type of device for self alignment. However, after the product is mass-produced, more models of exposure machines need to be introduced to meet the production demand, and the manufacturers and models of exposure machines will be diverse, so that subsequent alignment operations cannot be performed. SUMMARY

[0007] The technical problem to be solved by the present application is that in view of the technical problems existing in the prior art, the present application provides a photoetching verification layout and a photoetching plate for realizing the matching and correction of multiple different models of photoetching machines.

[0008] To solve the above technical problems, the technical solution provided by the present application is:

[0009] The photolithography verification layout comprises a plurality of sets of plate alignment marks, one or more sets of mutual set offset marks and a plurality of groups of CD resolution marks, the plurality of sets of plate alignment marks are located in the peripheral non-pattern area of the photolithography plate and correspond to different types of photolithography machines, the mutual set offset marks are located in the pattern area of the photolithography plate, and the plurality of groups of CD resolution marks are located in the pattern area of the photolithography plate.

[0010] As a further improvement of the above technical solution:

[0011] Each set of plate alignment marks comprises a plurality of mark points arranged in the form of multiple rows and multiple columns in the non-pattern area of the photolithography plate.

[0012] The plurality of groups of CD resolution marks are arranged in the form of multiple rows and multiple columns in the pattern area of the photolithography plate.

[0013] Each group of CD resolution comprises one or more groups of combined patterns, and each combined pattern has a different size; each combined pattern comprises a horizontal bar and a vertical bar.

[0014] The horizontal bar is concave, the vertical bar is convex, or the vertical bar is concave, the horizontal bar is convex, or both the horizontal bar and the vertical bar are concave, or both the horizontal bar and the vertical bar are convex.

[0015] Each plate alignment mark does not overlap with each other.

[0016] The mutual set offset mark comprises a Bar-bar mark and a Box-in-Box mark.

[0017] The Bar-bar mark comprises a first layer pattern and a second layer pattern, wherein the first layer pattern is enclosed by four rectangles to form a square, and the second layer pattern is also enclosed by four rectangles to form a square, wherein the square of the first layer and the square of the second layer have different sizes, and the left-right interval distance and the up-down interval distance between them are the same.

[0018] The Box-in-Box mark comprises a first layer square pattern and a second layer square pattern, and the first layer square pattern and the second layer square pattern have different sizes, and the left-right interval distance and the up-down interval distance between them are the same.

[0019] The application also discloses a photolithography plate comprising a plate body, wherein the plate body is provided with the photolithography verification layout as described above.

[0020] Compared with the prior art, the application has the following advantages:

[0021] The present application places different type of mask aligner mark on different position of the same mask, which is beneficial for matching different type of mask aligner, and can realize operation on two type of mask aligner; places mutual offset mark (or called overlay offset mark) in the pattern area of the mask, realizes mutual matching of different type of mask aligner, and is used for improving distortion; sets multiple groups of CD resolution mark in the pattern area of the mask, which can not only standardize initial state of blind exposure of the first layer of different type of exposure machine, but also can be used for monitoring distortion of mask aligner lens LENS. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The figure is an embodiment of the mask verification pattern of the present application in specific application.

[0023] Figure 2 The figure is a single field 9-point distribution of the CD resolution mark of the present application.

[0024] Figure 3 The figure is a multi-field 9-point distribution of the CD resolution mark of the present application (common center point).

[0025] Figure 4 The figure is a structure diagram of a group of combined patterns in the CD resolution mark of the present application.

[0026] Figure 5 The figure is a structure diagram of multiple groups of combined patterns in the CD resolution mark of the present application.

[0027] Figure 6 The figure is a structure diagram of the Bar-bar mark of the present application, wherein (a) is the pattern used for the first exposure; (b) is the superimposed pattern after the second exposure and development.

[0028] Figure 7 The figure is a structure diagram of the Box-in-Box mark of the present application, wherein (a) is the outer ring pattern used for the first exposure; (b) is the inner ring used for the second exposure; (c) is the superimposed result after the two exposures and development. DETAILED DESCRIPTION

[0029] The present application is further described below in combination with the drawings and specific embodiments.

[0030] As Figure 1As shown, the photolithography verification layout of the embodiment of the present application includes two sets of mask alignment marks, one set of mutual offset marks and multiple sets of CD resolution marks, the two sets of mask alignment marks are located in the peripheral non-graphic area of the photomask, and correspond to different types of photolithography machines (such as i12 and DUV204), wherein the corresponding marks of each mask do not overlap with each other; the mutual offset marks are located in the graphic area of the photomask, used to realize mutual offset through twice exposure, and finally corrected by measuring and calculating the offset value to achieve the matching purpose; the multiple sets of resolution marks are located in the graphic area of the photomask. The present application simultaneously places mask alignment marks of different types of photolithography machines at different positions on the same photomask, which is beneficial to the matching of different types of photolithography machines, and can realize operation on two types of photolithography machines; the mutual offset marks (or overlay offset marks) are placed in the graphic area of the photomask, realizing mutual offset matching of different types of photolithography machines, which is used to improve distortion; multiple sets of CD resolution marks are set in the graphic area of the photomask, which not only can standardize the initial state of the first layer exposure machine blind exposure of different types of exposure machines, but also can be used for periodic monitoring of the distortion of the photolithography machine lens LENS.

[0031] In a specific embodiment, the specific number of multiple sets of CD resolution marks is nine, arranged in three rows and three columns in the graphic area of the photomask, as shown in the single field of view 9-point distribution diagram Figure 2 , and as shown in the multi-field of view set 9-point distribution diagram Figure 3 (the specific number is determined according to the field of view size). Each set of CD resolution marks includes a set of combined graphics, including horizontal bars and vertical bars, as shown in Figure 4 . In other embodiments, each set of CD resolution marks can also include multiple sets of combined graphics, each set of combined graphics having different sizes, as shown in Figure 5 , which includes four sets of combined graphics, corresponding to sizes of 130nm, 140nm, 150nm and 190nm.

[0032] Specifically, the horizontal bar in each combined graphic is concave, and the vertical bar is convex; or the vertical bar is concave, and the horizontal bar is convex; or the horizontal bar and the vertical bar are both concave or convex, which is selected according to the actual situation.

[0033] The CD resolution marks of the present application are distributed in a 3*3 format according to left, middle and right and upper, middle and lower according to the field of view size of the photolithography machine lens, and the distortion of each position of the lens can be obtained through one-time exposure. Of course, according to the field of view size, it can also be extended to any more horizontal and vertical ratios.

[0034] In a specific embodiment, the mutual offset mark is distributed in the same field of view as five points in the center and four corners, specifically including Bar-bar mark and Box-in-Box mark. The Bar-bar mark includes a first layer of graphics and a second layer of graphics, wherein the first layer of graphics is enclosed by four rectangles to form a square, and the second layer of graphics is also enclosed by four rectangles to form a square, wherein the left and right spacing distances between the square of the first layer and the square of the second layer are the same, and the up and down spacing distances are the same, as shown in X1=X2, Y1=Y2 in Figure 6 .

[0035] The Box-in-Box mark includes a first layer of square graphics and a second layer of square graphics, and similarly, the left and right spacing distances between the first layer of square graphics and the second layer of square graphics are the same, and the up and down spacing distances are the same, as shown in X1=X2, Y1=Y2 in Figure 7 .

[0036] The embodiment of the present application also provides a photolithography plate, which includes a plate body, and the plate body is provided with the photolithography verification plate pattern as described above, and also has the advantages of the photolithography verification plate pattern as described above.

[0037] The present application will be further and completely described below in combination with a specific embodiment:

[0038] In the non-graphic area of the photolithography plate, i.e. the symmetrical position of the four corners of the photolithography plate, different model photolithography plate alignment marks (such as photolithography i12 and DUV204) are placed, and the two do not overlap. The mutual offset mark is placed in the central graphic area of the photolithography plate. The size of the mutual offset mark is small, and it can be placed in any idle area of the graphic area as needed. In order to ensure the accuracy of calculation, at least one set of mutual offset marks needs to be placed, and the more the number is, the more accurate the calculation will be.

[0039] The influence of the lens distortion of the photolithography machine on the CD marks of different sizes is different, wherein the fundamental reason for the distortion is that the light path in a region has changed, resulting in that the pattern cannot be completely restored. The size of the distortion is different, and the influence on the pattern is also different. For example, if the light path is offset by 200nm, the CD mark of 200nm and below will change obviously. However, for a pattern with a larger CD mark such as 2um, there will be no obvious change. Therefore, multiple sets of CD marks are placed at the same position, and the comparison of the topography and size of each position can detect whether the distortion has an influence on the required production size. According to the size of the field of view of the photolithography machine, a 3*3 format is distributed according to left, middle, right and upper, middle, lower. Each mark point is placed with a CD test pattern. The common field of view is a square, and the side length is 15mm, 17mm, 20mm, 22mm, 25mm, 33mm, etc.

[0040] Each point CD test pattern includes multiple groups of different size horizontal and vertical bars. The CD pitch size includes 1-100 nm, 100-1000 nm, 1-20 um, etc., and can include both concave and convex designs, or only one design as required.

[0041] The overlay offset markers include Bar-bar markers and Box-in-Box markers.

[0042] Bar-bar markers: the first layer is provided with four square patterns as a group in symmetrical distribution, the second layer is also provided with four square patterns as a second group, and the two are stacked in symmetrical distribution, i.e. X1=X2; Y1=Y2. The first layer and the second layer bar markers can be exchanged, and the patterns can be designed in reverse concave-convex.

[0043] Box-in-Box markers: the first layer is provided with a group of four square structure patterns, the second layer is provided with another group of four square structure patterns, and the two are stacked in symmetrical distribution, i.e. X1=X2; Y1=Y2. The first layer and the second layer Box markers can be exchanged, and the patterns can be designed in reverse concave-convex.

[0044] The above is only a preferred embodiment of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments. Any technical solution falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that, for ordinary skilled persons in the art, some improvements and refinements without departing from the principles of the present application shall be considered as falling within the protection scope of the present application.

Claims

1. A photolithographic verification layout, characterized in that, It includes multiple sets of plate alignment marks, more than one set of interlocking offset marks, and multiple sets of CD resolution marks. The multiple sets of plate alignment marks are located in the outer non-graphic area of ​​the photomask and correspond to different models of photomasks; the interlocking offset marks are located in the graphic area of ​​the photomask; and the multiple sets of CD resolution marks are located in the graphic area of ​​the photomask. The interlocking offset markers include bar-bar markers and box-in-box markers; The Bar-bar mark includes a first layer of graphics and a second layer of graphics. The first layer of graphics consists of four rectangles enclosing a square, and the second layer of graphics also consists of four rectangles enclosing a square. The squares in the first layer and the squares in the second layer are different in size, and the horizontal and vertical spacing between them is the same. The Box-in-Box label includes a first-layer square image and a second-layer square image. The first-layer square image and the second-layer square image are different in size, and the horizontal and vertical spacing between them are the same. Each set of the alignment marks includes multiple marker points, which are arranged in multiple rows and columns in the non-graphic area of ​​the photomask.

2. The photolithographic verification layout according to claim 1, characterized in that, Multiple sets of CD resolution markers are arranged in multiple rows and columns in the graphic area of ​​the photomask.

3. The photolithographic verification layout according to claim 2, characterized in that, Each CD resolution includes one or more sets of combined graphics, each set of graphics having a different size; each set of combined graphics includes horizontal and vertical bars.

4. The photolithographic verification layout according to claim 3, characterized in that, The horizontal bar is concave and the vertical bar is convex; or the vertical bar is concave and the horizontal bar is convex; or both the horizontal bar and the vertical bar are concave; or both the horizontal bar and the vertical bar are convex.

5. The photolithographic verification layout according to any one of claims 1 to 4, characterized in that, The alignment markers of each version do not overlap.

6. A photolithography plate, comprising a plate body, characterized in that, The plate body is provided with a photolithographic verification pattern as described in any one of claims 1 to 5.

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