JPH0380525A - Correcting method for proximity effect - Google Patents

Abstract

PURPOSE:To shorten processing time by calculating proximity effect correction for each hierarchical layer and each cell while maintaining the hierarchical layer structure for design data having a hierarchical layer structure of cells. CONSTITUTION:If resist coated on a board is exposed, when proximity effect is supplemented for a design pattern having a hierarchical layer structure of cells, a first frame region having a predetermined width is provided inside the boundary of the cells, and a second frame region having a predetermined width is provided inside the first region. When pattern data in each cell is corrected for the proximity effect, the pattern in the second region and the pattern inside the second region are to be corrected, and the pattern in the first region is used as a reference pattern. When the pattern of a hierarchical layer cell directly above each cell is corrected for the proximity effect, the pattern in the first region in each cell is added as to be corrected, the pattern in the second region in each cell is used as a reference pattern, and proximity effect corrective operation is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for correcting the proximity effect in pattern formation by direct writing with a charged beam or light exposure in a semiconductor manufacturing process.

Conventional Technology As patterns within semiconductor integrated circuit devices become finer and denser, a charged beam exposure device or an optical reduction projection exposure device is used to draw or expose such patterns. In order to improve the dimensional accuracy of the pattern caused by the proximity effect, correction is essential. A common method for correcting the proximity effect is to divide the pattern into multiple element shapes such as rectangles or triangles and apply an appropriate amount of electron irradiation to each shape, or to distort the pattern caused by the proximity effect. Figure 16 is a flowchart showing the conventional proximity effect correction method, and Figure 17 is a flowchart showing the conventional proximity effect correction method. This is a factor to explain this. In Figure 17, 1 and 2 are the top cell A
and cell boundaries of cell B in the second hierarchy; 3 and 4 are cell boundaries of the lowest cell C; and 5 to 10 represent patterns within the cells. In order to perform the above-mentioned proximity effect interpolation pattern, conventionally, pattern design data having a cell hierarchical structure as shown in FIG. ), after expanding the lower cells B and C in this data onto the top cell A and making the hierarchy of all patterns the same level (STEP 2
) As shown in Figure 13(b), the area is divided into a plurality of rectangular sub-zones by the dividing line 11 indicated by a dashed line, and the width of the typical distance that the proximity effect exerts on the periphery of each sub-zone is calculated. A reference frame area 12 (area indicated by a dot in the figure) is provided (STEP 3), and for each sub-zone, a pattern included in each of the sub-zones, and a sub-pattern included in each of the sub-zones is provided. Some of them exist in
For sub-patterns cut at sub-zone boundaries, reference frame area 1 for element figures of each sub-zone.
Calculation was performed while incorporating the effects of the patterns and elemental figures in 2 (STEP 4), and the correction effect was obtained (STEP 4).
EP5). (See for example (Shibu Journal Abridged Physics J, App 1. Phys, 50 (1979) pp. 4371-4387).

Problems to be Solved by the Invention However, with conventional methods, in order to process increasingly large-scale and highly integrated patterns, it is necessary to secure them as work files, and the disk space required to save the final processing results and the processing required. The present invention was tried in view of the above-mentioned problems, and it is possible to reduce the processing time by reducing the amount of processing data. The purpose is to provide a method.

Means for Solving the Problems The present invention aims to solve the above-mentioned problems.An exposure method for creating an exposure pattern on a substrate includes a plurality of cells each consisting of a set of design patterns corresponding to the exposure pattern.
Double inner and outer frame regions that are mutually nested and have a width that causes a proximity effect inside the boundaries of all cells except for design data having a hierarchical structure in which the plurality of cells indicate a mutually inclusive relationship. means for reorganizing the cell structure so that the boundary between the inner frame area and the outer frame area becomes a new cell boundary in place of the conventional cell boundary; means for carrying into a cell area of an upper layer and using it as a reference pattern area for performing a proximity effect complementation pattern for a pattern within the new cell boundary; A means for making a reference pattern area for performing an effect supplement pattern, and a means for making a correction target pattern area of the cell, which is obtained by subtracting the inside of the new cell boundary of the immediately lower cell from the inside of the new cell boundary, into a plurality of sub-pattern areas. Preparation for performing the series of proximity effect compensation patterns of means for dividing into zone regions, and means for forming a frame region having a width that causes a proximity effect around each of the sub-zones and attaching it to the sub-zones. a first means for carrying out the means for each cell in each hierarchy starting from the lowest hierarchical cell up to the highest hierarchical cell while maintaining the hierarchical structure of the cells of the design pattern data; and after the first means. For each cell
A proximity effect correction method includes a second means for performing a pattern of proximity effect correction.

Effect of the present invention With the above-described configuration, arithmetic processing can be performed for each layer and cell. Only those equipped with the means to perform one typical operation can execute the pattern of proximity effect complementation and apply this result to the same other cells as is, making it possible to shorten calculation time. The maximum value of data that must be the sum of the pattern data in a single cell, excluding the pattern data of all subordinate cells contained in that cell, in order to correct the pattern in that cell. The number of water required for the cell boundary of the immediately lower cell, the maximum amount that can be suppressed by adding the pattern in the double frame that touches the cell boundary. Processing becomes possible.

Example (Example 1) An example of a method for correcting the proximity effect that occurs when direct writing using an electron beam will be described below. Figure 2 is a factor for explaining this embodiment corresponding to the cell arrangement configuration in Figure 17(a). (~ First, CAD data of a pattern having a cell hierarchical structure is input into a computer for performing a pattern of proximity effect complementation (STEPI). Create a cell table corresponding to the cell hierarchy structure (STEP 2).In the cell table shown in Figure 3, the left column indicates the topmost cell. Arrange them in ascending order up to 3, which is the hierarchy corresponding to the cell corresponding to the cell, and indicate the cell names corresponding to these hierarchies in the right column.If there are multiple identical cells when creating a cell table, the same cells Register the lowest layer to the layer in which the cell C exists.In FIG. 17(a), cell C
In this example, cell C is registered as the third layer.

In this example, there is only one cell in each hierarchy.
A strong chicken that does not exist on the table A good chicken even if there are multiple cells Next 4. :, From 5TEP3 to 5TEPII (the pattern processing corresponding to the preparation for performing the pattern of proximity effect complementation is performed in the cell table in descending order from the cells existing in the lowest layer NMAM to the cells existing in the highest layer 1). Perform this for all cells registered in .

First, it is determined whether the cell in question is a top cell, that is, a cell in the N-1 hierarchy, and if it is not a top cell, the process proceeds to the following process (STEP 3). Let N be the hierarchy currently being considered. A double frame frame that is mutually nested is provided inside the cell boundary of each cell in the N hierarchy.
STEP 4). For each cell, the outer frame area (the area indicated by the dot in Figure 2) bounded by the cell border and the outer frame border, and the inner frame region bounded by the outer frame border and the inner frame border. For the width of the frame area (the area indicated by diagonal lines in FIG. 2), h and Lh are set to typical lengths that cause the proximity effect. Conditions such as the electron beam accelerating voltage and resist coating thickness are determined ('L).
The cell structure is reorganized to set the outer frame as a new cell boundary (87EP5). Furthermore, the outer frame area (top) incorporates the influence of the electron beam irradiated on the pattern in this area, and is used as a new reference pattern area when performing proximity effect correction patterns for the pattern in the correction target pattern area of the cell. Attach it to the cell (STEP 6).Here, the pattern area to be corrected and the inner area surrounded by the new cell boundary of the cell concerned. The area surrounded by the new cell boundary of the cell directly below is subtracted to become the correction target pattern area. 5 TEP 3 to all cells registered in the cell table existing in the layer N being considered.
After completing steps up to 6, move up the target hierarchy by one level (STEP
7). From 5TEP4 to 5TEP7, even if the process is omitted in the case of N-1, it is included in each cell for all cells registered in the cell table of the target layer N-1. Processing is performed to expand the outer and inner frame areas of all the cells in the layer N immediately below to the cells in the N-1 layer to make them in the same layer as the cells in question (STEP 8). To the part expanded to the cell in the N-1 layer, perform an operation to insert the pattern in the frame area outside the cell in the layer N immediately below as a pattern in the cell in the N-1 layer (STEP 9). The pattern in the frame area inside the cell in the layer N immediately below (
As a reference pattern area for the correction target pattern area of the cell of the N-1 layer, the 5TEP is attached to the cell of the N-1 layer (STEPIO) as described above.
By the operations from 4 to 10, the frame area C outside each cell becomes a reference pattern area for correction of the pattern within the new cell boundary, and at the same time it has the double character of being renormalized as a pattern of the immediately upper cell. Also, the frame area inside each cell has the dual characteristics of serving as a pattern within the new cell boundary and at the same time serving as a reference pattern area when correcting the pattern of the cell directly above it. As a result, the operations in K5TEP 4 through 10 create one pattern file for each different new cell.

FIG. 4 is a diagram for explaining this. In other words, in the example shown in FIG. 4(a) in which cell H of the Nth hierarchy exists as a lower cell within cell G of the N-1st hierarchy, 69 is the cell boundary 70 of cell G. The frame area 71 on the outside of cell G, the cell boundary 72 on cell H, the frame area 73 on the outside of cell H, and the frame group 74 on the inside of cell H are the frame areas outside cell G. Na resistance 70 is cell G
coincides with the cell boundary of the new cell G' for 72
coincides with the cell boundary of the new cell H' with respect to cell H. 75 is an area obtained by excluding the area within the cell boundary of cell H° from the area within the cell boundary of cell G°. 76 is a frame area outside cell H. 77 is an inside frame area of cell H. And 78 is a frame inside cell H. Indicates the area within the frame.

FIG. 4(b) shows a pattern file 79 associated with cell G'' for the cell tank bottom of FIG. 4(a).

The pattern file 79 is composed of four pattern subfiles: a pattern subfile 8Q in the reference pattern area 74 of the board cell G';

The pattern subfile 81 of the area 75 that becomes the actual pattern to be corrected in cell G' is carried in as the actual pattern to be corrected in cell G'.The pattern subfile 8B in the frame area 76 outside the lower cell H of cell G Cell G'
The pattern file 79 is composed of the pattern subfile 83 of the frame area 77 inside the lower cell H of the cell G as a reference pattern area. For the same cell that exists multiple times under the topmost cell (no matter what hierarchy this cell exists in) , % 5 TEP 4 to 10. By registering this as a pattern file 79, this result can be applied to other same cells in the same layer and different layers. For the pattern area to be corrected in sub-file 81 in b), divide this area into rectangular sub-zones in the same manner as in Fig. 17(b), and create sub-zones around the sub-zone boundaries for each sub-zone. , have a reference frame with a width that is a reference pattern area for use in correcting the pattern of each sub-zone (STEPI).Here, the width of the reference frame attached to the sub-zone is bit inside the cell and Even if the area is the same as the outer frame area, it is necessary to make the area that takes in the effects of nearby patterns consistent in a series of calculations.However, in a series of calculations ( The size of the sub-zone (the size of the sub-zone is determined based on the calculation accuracy etc.) As long as the above points are taken into account, the size of the sub-zone can be changed for each cell. There is no problem even if the sizes are different).

The series of processes from 5TEP 4 to 5TEPII only need to be performed once for the same cell, and can be applied to the same cells located in the same hierarchy or other hierarchies. Below, the operations from 5TEP3 to 5TEPII will be explained in detail using the drawings.As a result of the operations so far, in Figure 2, 13 and 14 are the 4th frame and inner frame frame of cell B, respectively, and 15 and 16 are the lower subordinates immediately below cell B. 17 and 18i; t, respectively show the outer and inner frame frames of the cell C immediately below the cell A. In addition, a new cell C whose cell boundary is cell Ci & 15, which is a lower cell of cell B, is created.
', the pattern of the outer frame area 21 in cell C is incorporated into the upper cell B, and cell B becomes a new cell B° with 13 as the cell boundary, and the pattern of the outer frame area 19 in cell B is Cell C, which is incorporated into upper cell A and is a lower cell immediately below cell A, becomes a new cell C' with 17 as the cell boundary, and the pattern of the outer frame area 23 in cell C is transferred as the pattern of upper cell A. Also, for cell A, the inner frame area 2CK of cell B and the inner frame area 2CK of cell C immediately below cell A are attached to cell A as a reference pattern area, and for cell B'', the lower order of cell B The frame area 22 inside cell C, which is a cell, is attached to cell B'' as a reference pattern area.
Is it a diagram showing the relationship of the hierarchical structure of cells corresponding to FIG. 17(a), but also FIG. 5(b)?飄 is a diagram showing a hierarchical structure as a result of reorganizing the cell structure in connection with the present invention. Except for the top cell A, the lower cells B and C
A change as shown in FIG. 5(b) occurs because the cell boundaries of the cell change. Figure 6 (Table) This is a diagram that explains the above situation by taking out cell C°, which is a lower cell of cell B'', but there is no lower cell in cell C'. Boundary 1 of cell C'
It is also possible to divide the area surrounded by 5 into rectangular sub-zones of appropriate size and create a frame area of the same width around each sub-zone. However, even if reference frame areas 32 and 33 are placed in the enclosure Q, reference frame areas are actually placed for all sub-zones. Area 324 yo Even if it overlaps with a part of area 21, 2
9 indicates the dividing line for forming sub-zones. 7th
The figure is a diagram illustrating the above-mentioned situation by taking out cell B'. Boundary 13 of cell B' and boundary 15 of lower cell C'
The pattern area to be corrected surrounded by is divided into rectangular sub-zones of appropriate size, and a frame of width is provided around the area. For representative sub-zones 36, 37 and 38, reference frames 39, 40 and 41 are arranged around them, respectively. In fact, reference frame areas are arranged for all sub-zones.The reference frame area 39 of the sub-zone 36 that is in contact with the cell boundary I3 overlaps with a part of the area 19, and The reference frame area 40 of the sub-zone 37 that is in contact with the area 22
Also, 42 indicates a dividing line for forming sub-zones. Below, an example will be described in which the proximity effect is corrected by optimizing the exposure amount to be given to the design pattern for each pattern (STEP 1
2). In FIG. 2, the initial estimation of the zero approximation is performed for the pattern existing in the external reference frame area 21 of the lowest cell C′, which is the lower cell of cell B°, or the element figure generated by dividing the pattern. Irradiation amount Qla
The c-table pattern is omitted in this figure. Here, Qs Q+n depends on exposure parameters such as electron beam acceleration voltage, resist seed coating thickness, etc., and should be set to an approximate value obtained from conventional experimental experience.
Based on this value, each sub-cell in cell C° shown in Fig.
Complementary patterns are made for each sub-zone for all patterns belonging to the zone, and the exposure amount for each pattern is determined. This force is given to the pattern in the reference frame area attached to each sub-zone by assuming the same estimated value For the pattern in the reference frame area that overlaps with the pattern of each sub-zone (even if a different corrected exposure amount is applied), the lower cell C' immediately below the cell A given by the cell boundary 17 shown in FIG. As for the complementary pattern for the pattern inside, it is sufficient to use the result for the pattern inside cell C'', which is a lower cell of cell B° and surrounded by cell boundary 15, as it is, and there is no need to create a new complementary pattern. 1 Next, for cell B'' in the second layer, for all patterns in the area excluding the inside of the cell boundary 13 of cell B' shown in FIG. 7 and the inside of the boundary 15 of cell C', As in the case of cell C', complementary patterns are executed for each sub-zone.

Finally, for the topmost cell A, the inside of the boundary 1 of cell A, and for the second layer cell B°, the boundary 13 of cell B' and the boundary of cell C° shown in Figure 7. Complementary patterns are similarly executed for each sub-zone for all patterns inside cell A except for inside cell A. In this series of operations from cell C'' to cell A, the first (Yo) calculation is performed assuming an estimated exposure amount Q1゜1t for the pattern in the reference frame area.For the pattern in the reference frame area This series of operations is performed multiple times as necessary by updating and giving the exposure amount obtained in the previous series of operations.In other words, the reference frame area or sub-zone of each of the above-mentioned sub-zones is Multiple representative patterns that well express the convergence status of the solution of a series of iterative calculations. If necessary, monitor the exposure amount determined through a series of complementary patterns each time for all patterns. E-value force length defined as Threshold E
Repeat the series of operations until it becomes smaller than orlt. Here, i indicates a specific pattern, m indicates the total number of patterns to be monitored, and n indicates the number of repetitions of a series of operations. Eo=1ti depends on exposure conditions and required correction accuracy. Here, the pattern of proximity effect complementation in 5TEP12 only needs to be performed once for the same cell, and can be applied to the same cells arranged in the same hierarchy and in other hierarchies. You can also start from any cell registered in the force support cell table, which is performed in order from lower cells to upper cells.

After completing the proximity effect correction pattern for all cells registered in the cell table by performing operations up to 5TEP12, proximity effect correction was completed for all cells below the topmost cell A. Apply the calculation results of each cell and complete the calculation (STEP 3).

(Example 2) FIG. 8 is a flowchart showing an example in which a cell having an array structure exists, and FIG. 9 is a factor for explaining this example. CAD data of a pattern having a hierarchical structure of cells is input into a computer for performing a pattern of proximity effect complementation (STEPI).

Next, as in the case of Example 1, a cell table corresponding to the design data shown in FIG. 9 is created (STEPI
2). Next, pattern processing corresponding to preparation for performing the proximity effect from 5TEP 3 to 5TEP II is performed on each array element cell in the cell having the array structure, the cell having the array structure, and the cell having the array structure. Perform this on the topmost cell. First, in FIG. 9, below the topmost cell D are the same element cells F50~
61 shows the case where there is a cell E configured using a 4×3 array.

There is a pattern 64 within each element cell F. here,
43 indicates the cell boundary of the topmost cell D, and 44 indicates the cell boundary of the cell E constituted by an array. Array element cell F in cell E is classified into nine groups (STEP
3). Group Gc1 of internal array element cells 60 and 61 that are not in contact with the boundary of cell E Upper left corner 5th generation
Water GTL, GTR, CIIL and Ge++ groups located at the upper right end 5a, lower left end 58 and lower right end 55, group Gy of 51.52 located at the upper end, group GB of 56.57 located at the lower end, left end 59 and Groups GL and GR are located at the right end 54. For array element cell F60.61 belonging to group Gc, consider that element cell as one sub-zone,
, a reference frame area 63 defined by a reference frame frame 62 is provided around the boundary of one representative array element cell 60 (STEP 4). Double inner and outer frames that are mutually nested are provided inside the cell boundaries of the cell E configured in an array (STEP 5). Here, 45 indicates an outer frame, and 46 indicates an inner frame. In the cell E configured with the array,
To the outer frame area 47 (area indicated by a dot) surrounded by the cell border 44 and the outer frame frame 45, and to the inner frame area 48 surrounded by the outer frame frame 45 and the inner frame frame 46. Although the width of h and Lh are the typical distances that cause the proximity effect, the cell structure is such that the outer frame 45 is set as the cell boundary of the new cell E' instead of the conventional cell boundary 44. Perform reorganization (STEP 6). Among the array element cells F, groups GTL, GTR, G8L, G-s*
, GT, Ga, GL, and GR, each element cell area is cut at the outer frame 45 of cell E, which is the boundary of cell E', and the portion 47 indicated by a dot is deleted. New cells FTL, FTR, FBL, F that replace each group with the previous element cell F
lIR, F Ding, F! , reconfigure as PL and PR (
STEP 7 ”). Perform processing to develop the outer and inner frame areas 4.7.48 of cell E, which is composed of the array, into cell D and make it the same layer as cell D (STEP 8
). However, in this example, if cell D is not the top cell, then Example 1
As explained in Figure 1, 5TEP3 to 5TEPIO
The above processing is performed for all different cells up to the topmost cell. To the part expanded to the top cell D
An operation is performed to insert the pattern ζ in the frame area 47 outside cell E as a pattern in cell D (ST
EP 9). The pattern in the frame area 48 inside cell E (ST) is attached to cell D as a reference pattern area for the correction target pattern area of cell D (ST
EP 10). Inside the boundary 43 of the top cell D
New cell boundary 4 of lower cell E configured in array
The pattern area to be corrected excluding the inside of 5 is divided into a plurality of sub-zones, and a frame area having a width affected by the proximity effect is set around each sub-zone (STEP II).

As in the case of Example 1, by optimizing the exposure amount to be given to the design pattern for each pattern,
The case of correcting the proximity effect is also shown. For a design pattern including cells having the array structure shown in FIG. 9, a proximity effect compensation pattern is performed as follows (STE
P12). In other words, first, for the representative cell 60 belonging to Gc among the array element cells, the exposure amount of the zeroth approximation is applied to the pattern existing in the reference frame area 63 associated therewith, or to the element figure generated by dividing the pattern. Q+n+t is given, and based on this, proximity effect complementation is performed on the pattern within the cell boundary of the representative cell 60. Next, for the pattern area to be corrected in the top cell D, a complementary pattern is applied to the pattern in the sub-zone area for each sub-zone in the same manner as in the examples shown in FIGS. 6 and 7 (STEP 13). ).

A series of complementary patterns of 5TEP12 and 5TEP13 are repeated as described above until E becomes less than the threshold value E o r l t. Next, the pattern result of the proximity effect complementation performed on the representative cell 60 in the cell having the array structure is applied equally to all array element cells (array element cell 61 in this example) belonging to other Gc. .

Next, groups GTL, GTR, G11L, G11ll
, GT, G11. For all array element cells belonging to GL and GM (thus, two cells excluding the dot area 47 which is the overlapping area between each element cell and the outer frame area of cell E, FTR, FIIL) , FI
In the R, FT, FB, FL and FR regions, Gc
Apply the complementary pattern result obtained in .

With the above steps, the calculation is completed (STEP 14).

(Example 3) FIG. 10 is a flowchart showing an example different from Example 2 in the case where cells having an array structure exist.
Figure 1 shows the factors for explaining this example. CAD data of a pattern having a hierarchical structure of cells, including cells having an array structure, is input into a computer for performing a pattern of proximity effect complementation ( STEP 1). Next, as in the case of Example 1, create a cell table corresponding to the design data shown in Figure 11 (STEP 2).
. Next, pattern processing corresponding to preparation for performing the proximity effect from 5TEP3 to 5TEpH is performed on each array element in the cell having the array structure, including the cell having the array structure and the cell having the array structure. Perform this on the topmost cell. In Figure 11, below the topmost cell D are the same element cells F50 to F6.
1 shows a case where there is a cell E configured by using a 4×3 array. There are 41 patterns 64 in each element cell F. Here, 43 indicates the cell boundary of the topmost cell D, and 44 indicates the cell boundary of the cell E configured in an array. The array element cell F in cell E is classified into two groups (STEP 3). In other words, a group Gc of internal array element cells 60 and 61 that are not in contact with the boundary of cell E, and other peripheral array element cells 50~
59 group Gp. For array element cells F 60 and 61 belonging to group Gc (regarding other element cells as one sub-zone, for L1 representative array element cells 60, a reference frame frame 6 is placed around the boundary).
2 is provided (STE
P4). For the surrounding array element cells F50 to F59 belonging to the group Gp (step 5), double inner and outer frames are provided inside the cell boundaries of each array element cell so that they are mutually nested. In FIG. 11, the situation regarding a typical array element cell 53 is explained.

That is, 67 indicates the outer frame, and 68 indicates the inner frame. Sub-zone boundary and outer frame border 6
7 and the inner frame area 6 surrounded by the outer frame frame 67 and the inner frame frame 68.
The width of 6 and the size of Lh are typical distances that produce a proximity effect. The cell structure is reorganized by setting the outer frame 67 as a new cell boundary instead of the conventional cell boundary and registering cell F as cell F' (STE
P6). In addition, the pattern in the outer frame area 65,
Recognized as a reference pattern when performing proximity effect complementation on patterns within new cell boundaries (STE
P7).

Next, processing is performed to expand the outer and inner frame areas to cell D, which is in the same hierarchy as cell D (STEP 8).

However, in this example (Table 1), when cell D is not the highest cell, the processing from 5TEP 3 to 5TEPIO in FIG. This is performed for all cells up to the topmost cell.Pattern processing in the outer frame area 65 of the portion expanded to the topmost cell D An operation is carried out to insert it as a pattern in cell D (STEP 9).

The pattern in the frame area 66 inside the frame is attached to cell D as a reference pattern area for the correction target pattern area of cell D (STEPIO).5TEP
The processes from 5 to 5TEP 10 are performed only for one representative cell F' belonging to GP (\The results are transferred to GP
It can be applied equally to other array element cells belonging to L1.
Area or plate inside the boundary 43 of the topmost cell D Cell E
The correction target for the top cell D is the area within the cell boundaries of the inner array element cells F60 and 61, and the area inside the outer frame frame of the surrounding array element cells F50 to F59. Divide the pattern area into multiple sub-zones and set up a frame area with the width affected by the proximity effect around each sub-zone (STEPll
). A case will be described below in which the proximity effect is corrected by optimizing the exposure amount to be given to each design pattern for each pattern, as in the case of the first embodiment. Proximity effect complementation is performed on a design pattern including cells having the array structure shown in FIG. 11 as follows.

In other words, first, for a representative internal array element cell 60 belonging to 8 Gc of array element cells, a pattern existing in the reference frame area 63 associated therewith, or an element figure generated by dividing the pattern, is calculated. Based on the exposure amount Q+nlL of the zero approximation, proximity effect complementary patterning is performed on the pattern in the sub-zone area (STEPI2). For a typical peripheral array element cell 53 belonging to the order L Gp, zeroth approximation exposure is applied to a pattern existing in the reference pattern area, that is, an outer frame area 65, or to an element figure generated by dividing the pattern. Quantity Ql n l
t, and based on this, proximity effect complementation is performed on the pattern within the new cell boundary 67 (STE
PI3). Next, for the pattern area to be corrected in the topmost cell, a complementary pattern is applied to the pattern in the sub-zone area for each sub-zone in the same manner as the examples in Figures 6 and 7 (STEP 4). . 5TEP12~5T
The series of complementary patterns of EP14 are repeated as described above until E is less than the threshold E orlt. First, the pattern result of the proximity effect complementation performed on the representative array element cell 60 belonging to Gc is applied equally to all array element cells belonging to other Gc (array element cell 61 in this example). . Next, the pattern result of proximity effect complementation performed on the representative array element cell 53 belonging to Gp is applied to all array element cells belonging to other Gp (array element cells 50 to 52 and 54 to 53 in this example).
59). The above completes the calculation (
STEPI5).

(Example 4) Figure 12C is a flowchart showing an example different from Examples 2 and 3 when cells with an array structure are present, and Figures 13 to 15 are factors for explaining this example. be. First, CAD data of a pattern having a hierarchical structure of cells, including cells having an array structure, is input into a computer for performing a pattern of proximity effect complementation (STEP
I). Next, as in the case of Example 1, a cell table corresponding to the design data shown in FIG. 13 is created (S
TEP2). Next L 5TEP3 to 5TEPI 1
The pattern processing corresponding to the preparation for performing the proximity effect up to 14 times is applied to each array element sensor 14 in the cell having the array structure, to the cell having the array structure, and to the topmost cell containing the cell having the array structure. Let's do it. First, FIG. 13 shows a case in which there is a cell E below the topmost cell D, which is composed of the same element cells F50 to F61 in a 4×3 array. Here, 43 indicates the cell boundary of the topmost cell D, and 44 indicates the cell boundary of the cell E, which is composed of an array. Double inner and outer frames that are mutually nested are provided inside the cell boundary of cell E (STEP 3).Here, numeral 45 indicates the outer frame, and 46 indicates the inner frame. In the cell E, which is composed of a The width of the inner frame area 48 surrounded by is set to h, and the size of h is a typical distance that causes a proximity effect.Instead of the conventional cell boundary 44, the outer frame frame 45 is used as a new cell E' Reorganize the cell structure to be set as cell boundaries (STEP 4'').Array element cell F in cell E
is reconfigured using four types of new element cells S, T, U, and W. FIG. 14 shows this reconstruction method.

70 is a cell boundary of array element cell F.

First, an element cell F having a width P× and a height P shown in FIG. Area S2 with width h and height h located at the lower right corner 74, area S3 with width h and height h located at the right upper limit 75, area S4 with width h and height h located at the right upper limit 75, SL at the left corner A region t having a width h and a height Pv-2Xh located at 76 between and 32
1. Area t2 with width h and height Pv-2Xh located at 77 between S3 and S4 at the right corner, width pX-2xh and height h located at 78 between Sl and S4 at the upper limit. Area u1, width P located at 79 between S2 and S3 at the bottom corner
K-2X h, area u2 with height h and central S
l * t I + S Q + u 2+ S 3
+t! * S 4 and is divided into 9 regions with region W existing at position 80 surrounded by ul. 71ζ This is a dividing line to distinguish these nine areas.Next, for example, the 60 array element cells F located in the center of FIG.
Consider as the target element cell. 73 areas S2 of the target element cell; 74 areas S3 of the element cell F that is in contact with the left side of the target element cell;
72 areas S1 of the element cell F that are in contact with the bottom of the target element cell and 4 of 75 areas S4 of the element cell F that are in contact with the target element cell at one point in the lower left corner.
Cell S is created by combining the two regions as shown in FIG. 14(b). 81 is the boundary of this cell S.
Next, the area u1 of 78 of the target element cell and the element cell F existing in contact with the top of the target element cell
Cell U is created by combining two areas of area u2 of 79 as shown in FIG. 14(b). 83 is this cell U
It is the boundary of Next, two areas, 76 area t1 of the target element cell and 77 area t2 of the element cell F that is adjacent to the left of the target element cell, are made of synthetic leather as shown in FIG. 14(b). Then, create cell T. 8
2 is the boundary of this cell T. Finally, 80 areas W of the target element cell are registered as cells W as shown in FIG. 14(b) (STEP 5). As shown in FIG. 15, within the cell boundary of cell E', the new element cell S
, T, U, and W to reconstruct (STEP 6)
. Here, 85 is a cell boundary between cells S, T, U, and W. Next, for each of these four types of array element cells, one is selected as a representative array element cell, and a reference frame area is provided around the cell boundary (STEP
7). In Figure 15, 86, 87, 88 and 89
are representative element cells of cells S, T, U and W, respectively, and 9
0.91.92 and 93 are representative element cells S, T, and
These are reference frame areas of U and W. Outer and inner frame areas 47 and 48 of cell E constituted by the array
is expanded to cell D to make it the same layer as cell D (STEP 8). However, in this example, if cell D is not the top cell, the 5TEP in FIG.
Processing from 3 to 5 TEPIO is performed for all different cells up to the top cell. The pattern in the outer frame area 47 of cell E in the portion expanded to the topmost cell D is inserted as a pattern in cell D (STEP 9). The pattern in the frame area 48 inside cell E is attached to cell D as a reference pattern area for the correction target pattern area in cell D (STEPIO). The correction target pattern area excluding the inside of the new cell boundary 45 of the configured lower cell E is divided into a plurality of sub-zones, and a frame with a width affected by the proximity effect is installed around each sub-zone. (STEPI
I). A case will be described below in which the proximity effect is corrected by optimizing the exposure amount to be given to each design pattern for each pattern, as in the case of the first embodiment. Proximity effect complementation is performed on a design pattern including cells having the array structure shown in FIG. 13 as follows. Sunawazaka First, each representative array element cell S, T, U
and W 86, 87, 88 and 89, the associated reference frame regions 90, 91° 92, and 9
The exposure amount Q+ of the zeroth approximation to the pattern existing in 3 or the element figure generated by dividing the pattern
n+t is given, and based on this, each representative cell 86 is
．． Proximity effect complementation is performed on patterns within the cell boundaries of 87, 88 and 89 (STEP 12). Next, for the pattern area to be corrected in the top cell D, a complementary pattern is applied to the pattern in the sub-zone area for each sub-zone in the same manner as in the examples of FIGS. 6 and 7 (STEP 13). ). A series of complementary patterns of 5TEP12 and 5TEP13 are expressed as described above, where E is the threshold value E o
This process is repeated until r l t is smaller than r l t.

Next, each representative cell 8 in the cell having an array structure
6.87. Apply the pattern results of proximity effect complementation performed for 88 and 89 to each of the other element cells S, T, U, and W.
applies equally to all array element cells belonging to . With the above steps, the calculation is completed (STEP 14).

As described above, in the 11th, second, third, and fourth embodiments (9) arithmetic processing is performed for each layer and cell by cell. Compared to
No matter what hierarchy they exist in, only those equipped with a means to perform a unique, representative calculation within the same cell group can perform pattern processing and proximity effect complementation patterns corresponding to the preparation for performing the proximity effect complementation pattern. No row ＼ Since the result can be applied equally to other cells of the same type, the calculation processing time is significantly reduced. In addition, if the arrangement of patterns in all cells except cells that do not have an array structure has two-dimensional periodicity, then the cell is reconfigured as a set of multiple array element cells. Later 2nd. It is possible to apply the third and fourth embodiments. Furthermore, second. In the third and fourth embodiments, if the size of the array element cell <, it is too large for one processing unit (so), the array element cell is further divided into a plurality of sub-zones.・It is also possible to add a means of correction for each zone and implement it. The force mentioned above has an arbitrary number of layers greater than or equal to 2, and L
In addition, it can be applied in the same way as L, even if there are cells that are not composed of multiple types of arrays and multiple cells that are composed of arrays in any hierarchy. In addition, in this example, the shape and size of the pattern or element figure is adjusted to the optimal value. It is possible to carry out the same method by changing the method.Furthermore, the proximity effect phenomenon that occurs during force exchange, ion beam polishing, and light exposure, which is explained only in the case of electron beam direct writing, can be applied. Effects of the Invention As is clear from the above explanation, according to the present invention, the proximity effect correction method can be similarly applied to design data that has a hierarchical structure of cells, while maintaining the hierarchical structure. By performing proximity effect complementation patterns for each layer and each cell, the amount of data processed at one time is reduced, and pattern data for large-scale VLSI chips can be processed using a reasonable amount of magnetic disk resources. It is possible to perform processing in a short time.Furthermore, it is equipped with a means to perform a unique and representative operation on the same cells in the design data (regardless of the hierarchy in which they exist). Only the pattern processing corresponding to the preparation for the pattern of proximity effect complementation and the pattern processing of proximity effect complementation are not performed. As described above, the present invention has the following features when performing proximity effect correction:
It has a tremendous effect.

[Brief explanation of drawings]

Fig. 1 is a flowchart showing arithmetic processing in the first embodiment of the present invention, Fig. 2 shows a cell arrangement for explaining this embodiment, and Fig. 3 shows a cell table for explaining this embodiment. Figure 4 is for explaining the pattern file; Figure 5 is for explaining the cell hierarchical structure of this embodiment; Figures 6 and 7 are for explaining the pattern file in detail; The figure is a flowchart showing arithmetic processing for array cells in the second embodiment of the present invention, Figure 9 is a cell arrangement for explaining this embodiment @ Figure 10 is the operation for array cells in the third embodiment of the present invention FIG. 11 is a flowchart showing the processing, and FIG. 11 shows the cell arrangement for explaining this embodiment. FIG. 12 is a flowchart showing the calculation processing for array cells in the fourth embodiment of the present invention.
Figure 13 shows the cell arrangement for explaining this example.
Figure 4 shows a method for reconfiguring array element cells to explain this embodiment. Figure 15 shows a layout of reconfigured element cells to explain this embodiment. Figure 16 shows a conventional sub-cell arrangement. FIG. 17 is a flowchart showing processing by the zone frame method, and is a cell layout diagram for explaining the conventional sub-zone frame method. l...Cell boundary of the topmost cell A 2...Cell boundary of cell B in the second layer 3, 4...Cell boundary 13 of cell C...Outer frame within cell B Frame (cell B°
), 14... Inner frame in cell B & , 15.17... Outer frame frame in cell C (cell border of cell C°), 16.18... Cell C
Inner frame-like area 19...outer frame area in cell B (external reference frame area of cell B''), 20
...Inner frame area in cell B (internal reference frame area for cell B' of cell A), 21.23...
...Outer frame area vIh22, 24 in cell C...
...Inner frame area 29 in cell C...Sub...
Parting lines 30, 31 for forming zones...Sub, each of the sub zone areas 32, 33...Sub...
Reference frame area attached to zone @ 36-38...
... Internal class of sub-zone vA39-41 ... Reference frame area 42 attached to sub-zone ... Division line 43 for forming sub-zone ... Cell of topmost cell D Boundary 44... Boundary 45... Outer frame frame within cell E (boundary of cell E'), 46... Cell E Inner frame-like 47...Outer frame area in cell E (external reference frame area for cell D of cell E°), 48...Inner frame area in cell E (
internal reference frame area of cell D for cell E'), 4
9...Dividing line 62 giving the boundary of element cell F...
・Frame-like 63 attached to internal array element cell F・
...Reference frame area of internal array element cell F [64
...Pattern in array element cell F, 65...
Frame area outside the surrounding array element cell F (cell F
), 66... Inner frame area of surrounding array element cell F 67... Outer frame area of surrounding array element cell F 68... Surrounding array element cell Inner frame of F 70... Boundary of array element cell 71... Inside array element cell 9
Dividing line 72 for dividing into two areas: Area S+ having width h and height h, located at the upper left corner within the array element cell, 73: Located at the lower left corner within the array element cell Area S2.74 having width h1 and height h. Area S2.74...located at the lower right corner within the array element cell. Area S3.75 having width h and height h...located at the right upper limit within the array element cell. A region S4.76 having a width h and a height h...
Width h1 Height P1 located at the left corner in the array element cell
Area t1.77 with width h and height Pv-2X h located at the right corner in the array element cell t2.78... Located on the dirt floor in the array element cell Area u1.7 with width px-2Xh and height h
9...Width Px- located at the lower corner within the array element cell
Area u2.80 having a width of 2X h and a height h, 81...A region W having a width of PX-2Xh and a height of Pv-2xh located at the center of the array element cell, 81...Area S +
, S2. Item 882 of cell S created by combining S3 and S4...Term 883 of cell T created by combining area 1+ and t2...Created by combining areas u1 and u2 Boundary 84 of cell U...Term 885 of cell W created using area W...Cell term 886 of cells S, T, U, and W...Representative element of cell S 1<
87... Representative element SE of cell T 88... Representative element SE of cell U k 89... Representative element SE/l, z of cell W 89... Representative element SE of cell W )L
=, 90...Reference frame headboard 91 of representative element cell S...Reference frame headboard 92 of representative element cell T
...Reference frame headboard 93 of representative element cell U...
・Reference frame tilt plate of representative element cell W

Claims (10)

[Claims] (1) In a method of performing proximity effect correction on a design pattern having a hierarchical structure of cells when exposing a resist coated on a substrate using a charged beam or light, means for providing a first frame region having a predetermined width within the first frame region; means for providing a second frame region having a predetermined width inside the first frame region; When effect correction is performed, a pattern in the second frame area and a pattern inside the second frame area are used as correction target patterns, a pattern in the first frame area is used as a reference pattern, and each of the above When correcting the proximity effect of the pattern of the cell immediately above the cell,
Adding a pattern in the first frame area in each cell as a correction target pattern, and using a pattern in the second frame area in each cell as a reference pattern,
A proximity effect correction method comprising means for performing a proximity effect correction calculation. (2) Regarding a plurality of identical cells, a proximity effect correction calculation is performed on one of the cells, and the result is applied to the other identical cells. Proximity effect correction method. (3) In claim 1, for a cell having an array structure in which element cells are basic units, surrounding element cells that are in contact with the boundary of the cell having the array structure among the cells having the array structure means for providing a frame area having a predetermined width outside the boundary of the element cell for all element cells except for The entire pattern data is the pattern to be corrected, and the pattern data in the frame area provided outside the element cell is
A proximity effect correction method comprising means for performing a proximity effect correction calculation using data as a reference pattern. (4) In claim 1, for a cell having a predetermined size, the The area inside the first frame area is divided into a plurality of sub-zones, and a third frame area having a predetermined width is provided outside the boundary of each sub-zone, and all of the areas within each sub-zone are A proximity effect correction method, comprising means for performing a proximity effect correction calculation using pattern data as a correction target pattern and a pattern in the third frame area as a reference pattern. (5) A method of performing proximity effect correction for cells having an array structure with respect to a design pattern including cells having an array structure when exposing a resist coated on a substrate using a charged beam or light. In this step, the element cell is divided into nine rectangular areas of 3×3, and the four different rectangular areas at the corners of each element cell among the four element cells that are in contact with each other are collected to form a second cell. year,
Among two element cells that touch each other on one side, the two different rectangular areas at the side corners of each element cell are collected to form a third
and means for making the rectangular area at the center of the element cell a first cell, and a predetermined width outside the boundaries of each of the first, second, third, and fourth cells. means for providing a frame area having a frame area having a frame area having a frame area of each of the first, second, third and fourth cells; All pattern data in the cell is set as the correction target pattern, and the first,
A proximity effect correction method comprising means for performing a proximity effect correction calculation using a pattern in a frame area provided outside each of the second, third and fourth cells as a reference pattern. (6) In claim 1, the predetermined width of the first and second frame regions is a width that is longer than the scattering length of backscattered electrons, which is a typical distance that causes the proximity effect. A proximity effect correction method characterized by: (7) In claim 3, the proximity effect is characterized in that the predetermined width of the frame region is longer than the scattering length of backscattered electrons, which is a typical distance that causes the proximity effect. Correction method. (8) Claim 4 is characterized in that the predetermined width of the third frame area is longer than the scattering length of backscattered electrons, which is a typical distance that causes the proximity effect. Proximity effect correction method. (9) For a cell that does not have an array structure, if the pattern arrangement within the cell has two-dimensional periodicity, the cell is re-created as a set of a plurality of array element cells. 6. The proximity effect correction method according to claim 3, wherein the proximity effect correction calculation is performed after the configuration. (10) Adding a method of further dividing each array element cell into a plurality of sub-zones in a cell having an array structure, and performing proximity effect correction on the pattern within the array element cell for each sub-zone. A proximity effect correction method according to claim 3 or 5, characterized in that: