How to check the placement of scribe line patterns in the layout

Abstract

This invention discloses a method for checking the placement of scribe lines in a layout, comprising: Step 1, determining the size of individual units in the layout; Step 2, selecting an individual unit to be searched, and expanding the search area of ​​the individual unit to an area with 1 / 2 the size of the exposure area; Step 3, checking whether the selected individual unit is a duplicate unit, including: retrieving scribe lines in the layout that partially overlap with the search area of ​​the selected individual unit; when a scribe line that partially overlaps with the search area of ​​the selected individual unit is found, the selected individual unit is a duplicate unit; Step 4, providing a prompt for the area of ​​duplicate units. This invention enables automatic checking, thereby improving checking efficiency and saving time costs, and also enables comprehensive checking of all individual units in the layout, improving the accuracy of the check.

Description

Technical Field

[0001] This invention relates to a semiconductor integrated circuit manufacturing method, and specifically to a method for inspecting the placement of dicing patterns in a mask. Background Technology

[0002] Layout data needs to be incorporated into the mask frame before it can be used in wafer fabrication. Improper use of the edge (EDGE) function during the design of the mask frame can lead to defects such as incorrect placement of the overlay mark (OVLmark) in the dicing slot, resulting in more mask re-makes.

[0003] like Figure 1 The diagram shown is a schematic of an existing layout; the photomask 101a contains a layout 101, and the layout 101 contains multiple individual cells 102. Each individual cell 102 corresponds to a chip unit structure; a dicing groove 103 is provided on the periphery of each individual cell 102. A pattern structure is provided on the dicing groove 103, which is typically various marks, including overlay marks 103. Figure 1 As shown, an abnormal situation occurred where two overlay marks 103 were placed repeatedly.

[0004] Because abnormalities can occur in the placement of the dicing groove pattern, it is necessary to check the placement of the dicing groove pattern in the layout. The current method for checking the placement of the dicing groove pattern in the layout is to perform manual visual sampling. For example... Figure 2 As shown, in the area corresponding to the dashed circle 104 in layout 101, there are two identical overlay marks. The dashed circle 105 is an enlarged view of the dashed circle 104. It can be seen that the overlay marks in the two elliptical areas corresponding to marks 106a and 106b are the same.

[0005] In photolithography, the area exposed in one step is called a shot area. When the shot area is large, it is... Figure 2 As can be seen, visual inspection is highly random and it is difficult to conduct a complete inspection. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for inspecting the placement of diced slot patterns in a layout, which can realize automatic inspection, thereby improving inspection efficiency and saving time and costs, and can also achieve comprehensive inspection of all individual units in the layout and improve the accuracy of inspection.

[0007] To solve the above-mentioned technical problems, the present invention provides a method for placing the scribe groove pattern in an inspection layout, comprising the following steps:

[0008] Step 1: Determine the size of the individual units in the layout.

[0009] Step 2: Select a single entity to be searched and expand the search area of ​​the single entity to an area with a size of 1 / 2 of the exposure area.

[0010] Step 3: Check whether the selected monomer is a repeating monomer, including:

[0011] The dicing pattern that partially overlaps with the search area of ​​the selected monomer is retrieved from the layout. When the dicing pattern that partially overlaps with the search area of ​​the selected monomer is retrieved, the selected monomer is a repeating monomer.

[0012] Step 4: Provide prompts for the regions of the repeating monomers.

[0013] A further improvement is to check whether all the monomers in the layout are duplicate monomers.

[0014] A further improvement is that, in step two, the search area of ​​each of the individual units in the layout is expanded to an area with a size of 1 / 2 of the exposure area.

[0015] A further improvement is that step three of the loop performs an inspection on all the individual units in the layout, including:

[0016] After completing step three for the selected monomer, determine whether the selected monomer is the last one. If it is the last one, proceed to step four. If it is not the last one, read the next monomer and use the next monomer as the new selected monomer, and then proceed to step three.

[0017] A further improvement is that step three includes the following sub-steps:

[0018] Step 31: Read the original data of the layout into memory;

[0019] Step 32: Construct geometric relationships for the original data of the read-in layout; the geometric relationships are implemented through a tree index, and the index record of each level of the tree index is in the form of (box, id), where id points to the graphic corresponding to the node, and box is a rectangle and the rectangle of box must cover all the graphics pointed to by the node;

[0020] Step 33: Perform a step-by-step retrieval based on the tree index to obtain the slicing groove pattern that partially overlaps with the search area of ​​the selected single entity.

[0021] A further improvement is that the original data of the layout is in the format of GDSII or OASIS.

[0022] A further improvement is that C++ streams are used to read data in step 31.

[0023] A further improvement is that, in step 32, the tree index is an R-tree or a B-tree.

[0024] A further improvement is that, in step three, the dicing groove pattern includes overlay marks.

[0025] A further improvement is that steps one through four are implemented automatically by the program.

[0026] This invention identifies dicing patterns that partially overlap with the search area of ​​individual units by searching the layout, thereby automatically checking the placement of these dicing patterns and improving inspection efficiency while saving time. Furthermore, by cyclically setting the settings, this invention can perform a comprehensive inspection of all units in the layout, thus improving inspection accuracy. Attached Figure Description

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0028] Figure 1 This is a schematic diagram of the existing territory;

[0029] Figure 2 This is a schematic diagram of the observation of the layout in the existing method of placing the dicing groove pattern in the inspection layout;

[0030] Figure 3 This is a flowchart of a method for checking the placement of scribe lines in a layout according to an embodiment of the present invention;

[0031] Figures 4A-4F This is a schematic diagram of each step in the method for placing the scribe groove pattern in the inspection layout according to an embodiment of the present invention. Detailed Implementation

[0032] like Figure 3 The diagram shown is a flowchart of a method for checking the placement of the dicing groove pattern in layout 201 according to an embodiment of the present invention; as shown Figures 4A to 4F The diagram shown is a schematic representation of each step in the method for checking the placement of the scribe groove pattern in layout 201 according to an embodiment of the present invention. The method for checking the placement of the scribe groove pattern in layout 201 according to an embodiment of the present invention includes the following steps:

[0033] Step 1, such as Figure 4A As shown, the size of unit 202 in layout 201 is determined.

[0034] The single unit 202 corresponds to a chip unit structure; a dicing groove 203 is provided on the periphery of the single unit 202. A pattern structure is provided on the dicing groove 203, which is usually a mark, including an overlay mark (OVL mark).

[0035] Step 1 corresponds to Figure 3 Step S101 in the process is: determining the size of the monomer.

[0036] Step Two, as follows Figure 4A As shown, a single entity 202 to be searched is selected, and the search area 204 of the single entity 202 is expanded to an area with a 1 / 2 exposure (shot) area size.

[0037] Typically, one exposure area corresponds to the area corresponding to one exposure, and one exposure area can include the area of ​​multiple units 202, that is, one exposure can expose multiple units 202.

[0038] Figure 4A In the search area 204, the search area 204 is located in a rectangle, and there is an overlay mark corresponding to a mark 205 in the search area 204. The overlay mark is the overlay mark that needs to be detected.

[0039] In this embodiment of the invention, all monomers 202 in the layout 201 are checked to see if they are duplicate monomers 202.

[0040] The expansion step of the monomer 202 needs to be repeated to expand the search area 204 range of each monomer 202 in the layout 201 to an area with a 1 / 2 exposure area size.

[0041] Step two corresponds to Figure 3 Step S102 in the text is: expanding each monomer to a 1 / 2 shot size region.

[0042] Step 3: Check whether the selected monomer 202 is a repeating monomer 202, including:

[0043] In the layout 201, a dicing pattern that partially overlaps with the search area 204 of the selected monomer 202 is retrieved. When a dicing pattern that partially overlaps with the search area 204 of the selected monomer 202 is retrieved, the selected monomer 202 is a repeating monomer 202.

[0044] In this embodiment of the invention, step three of the loop performs an inspection on all the individual units 202 in the layout 201, including:

[0045] After completing step three for the selected monomer 202, determine whether the selected monomer 202 is the last one. If it is the last one, proceed to step four. If it is not the last one, read the next monomer 202 and use the next monomer 202 as the new selected monomer 202, and then proceed to step three.

[0046] Step 3 of the loop corresponds to Figure 3 Steps S103, S104, and S105 in the process; Figure 3 Step S103 is to check whether each monomer in the region is a duplicate monomer; step S104 corresponds to determining whether the selected monomer 202 is the last one; step S105 corresponds to reading the next monomer 202 and using the next monomer 202 as the new selected monomer 202.

[0047] Step three includes the following sub-steps:

[0048] Step 31, as Figure 4B As shown, the original data 206 of the layout 201 is read into memory.

[0049] In some embodiments, the original data 206 of the layout 201 is in the format of GDSII or OASIS.

[0050] Figure 4B In the process, the memory reading steps are shown in label 207, and C++ streaming is used to read the memory in step 31.

[0051] Step 32: Construct geometric relationships for the original data 206 of the read-in layout 201; the geometric relationships are implemented through a tree index, and the index record of each level of the tree index is in the form of (box, id), where id points to the graphic corresponding to the node, and box is a rectangle and the rectangle of box must cover all the graphics pointed to by the node.

[0052] Figure 4B In this context, the steps for constructing geometric relationships are illustrated in label 208.

[0053] In some embodiments, the tree index is an R-tree or a B-tree.

[0054] Taking R-tree as an example:

[0055] An R-tree index is a height-balanced tree where leaf nodes store pointers to data. Furthermore, R-trees guarantee that searching planar data requires accessing only a small subset of nodes. The index records in the leaf nodes of an R-tree are in the form of (box, id), where id points to a shape in the planar data. The box represents a rectangle, a bounding box, used to encompass the indexed planar data shape. For example... Figure 4C As shown, in the R-tree node (box, id), box corresponds to rectangle 301, and id corresponds to figure 302. Rectangle 301 is a bounding box, which includes four vertices, denoted by P1(x, y), P2(x, y), P3(x, y), and P4(x, y).

[0056] An R-tree consists of multiple nodes and is hierarchical. In an R-tree, the number of child nodes for each node is limited; assuming each node has at most M child nodes, where m <= M / 2, then an R-tree has the following properties:

[0057] Except for the root node, the number of child nodes of each node must be between [m, M].

[0058] For each leaf node's index record (box, id), box is the smallest rectangle that can contain the graphic;

[0059] For each index record (box, id) of a non-leaf node, box is the smallest rectangle that can contain all child nodes;

[0060] The root node must have at least two child nodes;

[0061] All leaf nodes are on the same level.

[0062] like Figure 4D As shown, multiple nodes are represented by R1, R2, R3, R4, R5, R6 and R7 respectively. Figure 4D The diagram shows two levels: level 3031 and level 3032, with level 3032 being a sub-level of level 3031. Nodes R1 and R2 are in level 3031, while nodes R3 through R7 are in level 3032. Nodes R3 through R7 are all leaf nodes. Nodes R3 through R5 are children of node R1, and nodes R6 and R7 are children of node R2.

[0063] Step 33: Perform a step-by-step retrieval based on the tree index to obtain the slicing groove pattern that partially overlaps with the search area 204 of the selected single entity 202.

[0064] like Figure 4EAs shown, in this embodiment of the invention, the area where graphics need to be modified in batches is defined as a search rectangle S, i.e., the search area 204. The R-tree is searched to retrieve graphics with overlapping parts, such as... Figure 4E The graphs corresponding to nodes R3 and R6 in the graph.

[0065] Depend on Figure 4E As shown, during the retrieval process, the graphic (box graphic) of nodes R1 and R2 in layer 3031 is first compared with the search rectangle S to see if there is any overlap. It can be seen that nodes R1 and R2 overlap with the search rectangle S.

[0066] Next, the box shapes of the child nodes of nodes R1 and R2 are compared with the search rectangle S to see if they overlap. It can be seen that the box shapes of nodes R3 and R6 overlap with the search rectangle S.

[0067] The above search process can employ Figure 4F As can be seen, the retrieval process is simple and can be automated.

[0068] In this embodiment of the invention, the dicing groove pattern includes overlay marks, that is: the patterns corresponding to the id of nodes R3 and R6 are overlay marks.

[0069] Step 4: Provide prompts for the region of the repeating monomer 202.

[0070] Step four corresponds to Figure 3 Step S106 in the process is to obtain the result.

[0071] In this embodiment of the invention, steps one through five are implemented automatically by a program.

[0072] The program is implemented using C++ code.

[0073] A C++ code segment implemented using the method of this embodiment of the invention is as follows:

[0074]

[0075] The method described in this invention can be implemented with just a few hundred lines of C++ code.

[0076] This invention, through a search of layout 201, identifies dicing patterns that partially overlap with the search area of ​​individual unit 202. This enables automatic inspection of the placement of dicing patterns in layout 201, thereby improving inspection efficiency and saving time. Furthermore, by cyclically setting this invention, a comprehensive inspection of all individual units 202 in layout 201 can be achieved, thus improving inspection accuracy.

[0077] The present invention has been described in detail above through specific embodiments, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A method for checking the placement of scribe lines in a layout, characterized in that, The steps include: Step 1: Determine the size of the individual units in the layout; The single unit corresponds to a chip unit structure; a dicing groove is provided on the periphery of the single unit; a graphic structure is provided on the dicing groove, the graphic structure being various marks, including overlay marks; Step 2: Select a single entity to be searched and expand the search area of ​​the single entity to an area with 1 / 2 the size of the exposure area; Step 3: Check whether the selected monomer is a repeating monomer, including: The dicing pattern that partially overlaps with the search area of ​​the selected unit is retrieved from the layout. When the dicing pattern that partially overlaps with the search area of ​​the selected unit is retrieved, the selected unit is a repeating unit. The dicing groove pattern is an overlay mark; Step 4: Provide prompts for the regions of the repeating monomers.

2. The method for placing the scribe line pattern in the inspection layout as described in claim 1, characterized in that: All the monomers in the layout are checked to see if they are duplicate monomers.

3. The method for placing the scribe line pattern in the inspection layout as described in claim 2, characterized in that: In step two, the search area of ​​each of the individual units in the layout is expanded to an area with a size of 1 / 2 exposure area.

4. The method for placing the scribe line pattern in the inspection layout as described in claim 3, characterized in that: Step three of the loop performs an inspection on all the individual units in the layout, including: After completing step three for the selected monomer, determine whether the selected monomer is the last one. If it is the last one, proceed to step four. If it is not the last one, read the next monomer and use the next monomer as the new selected monomer, and then proceed to step three.

5. The method for placing the scribe line pattern in the inspection layout as described in claim 1, characterized in that: Step three includes the following sub-steps: Step 31: Read the original data of the layout into memory; Step 32: Construct geometric relationships for the original data of the read-in layout; the geometric relationships are implemented through a tree index, and the index record of each level of the tree index is in the form of (box, id), where id points to the graphic corresponding to the node, and box is a rectangle and the rectangle of box must cover all the graphics pointed to by the node; Step 33: Perform a step-by-step retrieval based on the tree index to obtain the slicing groove pattern that partially overlaps with the search area of ​​the selected single entity.

6. The method for placing the scribe line pattern in the inspection layout as described in claim 5, characterized in that: The original data of the map is in the format of GDSII or OASIS.

7. The method for placing the scribe line pattern in the inspection layout as described in claim 6, characterized in that: In step 31, C++ streams are used for reading.

8. The method for placing the scribe line pattern in the inspection layout as described in claim 6, characterized in that: In step 32, the tree index is an R-tree or a B-tree.

9. The method for placing the scribe line pattern in the inspection layout as described in claim 1, characterized in that: In step three, the dicing groove pattern includes overlay marks.

10. The method for placing the scribe line pattern in the inspection layout as described in any one of claims 1-9, characterized in that: Steps one through four are completed automatically by the program.

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