JPH065502A - Method and equipment for conversion of exposure data - Google Patents

Abstract

PURPOSE:To provide a method and equipment for conversion processing of exposure data which have a high dimensional precision and high reliability. CONSTITUTION:A dimensional shift processing process S100 in which the amount of dimensional shift of a dimension needing the highest dimensional precision out of a plurality of dimensions for which a proximity effect is to be considered simultaneously is determined in the case when the dimensional shift is executed for the dimensions of a designed pattern based on inputted designed pattern data, and dimensional shift processings of the dimensions in a plurality to be considered simultaneously are executed in the determined amount of the dimensional shift so as to determine shift pattern data, and a figure processing process S200 in which a figure represented by the shift pattern data is divided into basic figures set beforehand, are provided. An exposure amount correcting process S300 in which exposure amount data are determined for each divided basic figure and, moreover, corrected in consideration of the mutual effect in the case when exposure is conducted on the basis of the exposure amount data for each basic figure, and thereby exposure data are determined, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure data conversion method and an exposure data conversion processing device, and more particularly to an exposure data conversion method and an exposure data conversion processing device for exposing a pattern of the sub-quarter μm order.

The degree of integration of electronic devices is increasing year by year, and a technique for exposing a sub-quarter μm (˜about 0.25 μm) device is required. The electron beam exposure technique is known as an exposure technique having high resolution. However, in order to secure the required dimensional accuracy, it is necessary to consider the influence of the proximity effect, and it is desired to develop a proximity effect correction method that is effective even for the sub-quarter μm pattern.

[0003]

2. Description of the Related Art The proximity effect means that when an electron beam is irradiated, reflected electrons from the irradiated resist or substrate increase the apparent exposure amount of a graphic pattern in the vicinity, and a fine line is drawn. It refers to the effect of becoming harder. In electron beam exposure or the like, the backward scattering (direction opposite to the electron beam irradiation direction) spreads over a wide range, and therefore has a greater influence than the forward scattering (electron beam irradiation direction). Therefore, when the exposure patterns are close to each other, the bleeding of scattered electrons exposes a region that should not be exposed, resulting in a decrease in contrast.

Conventionally, as a method of correcting the proximity effect, exposure is performed by taking into consideration the influence of the proximity effect within the exposure pattern and between the exposure patterns by a sum of two exponential functions representing forward scattering and back scattering (proximity effect function). The method of determining the dose (electron beam dose) is often used (for example, "[C
orrections to proximity effectss in electron beaml
ithography], M.Parikh: j.Appl.Phys. 50 (6), June 1979
"reference. ). In this case, in order to reduce the pattern dimension change amount with respect to the exposure amount change, to obtain a vertical cross-sectional shape when using a positive resist, or to obtain a desired residual film when using a negative resist,
As shown in FIG. 6, the exposure intensity F that is inversely proportional to the exposure amount F
It is desirable to perform the exposure at a position where the distance X from the pattern center does not change with respect to the change of (X), and the pattern size required at a position such that the distance from the pattern center is point A using the exposure intensity curve. Dimension shift amount, so that
That is, the shift amount of the dimension to be reduced or increased from the dimension of the design pattern to obtain the desired pattern dimension is determined (for details, refer to "[Proximity effect]".
correction for negative resist in erectron beam l
ithography], N.Nakayama et.al.:Internationsal Confe
rence on Electron & Beam Science & Technology1981
See. ).

In order to perform exposure pattern data conversion processing to obtain exposure data having sufficient dimensional accuracy,
In the dimension shift correction process, the shift amount is reduced for an exposure pattern having a relatively large dimension (design pattern width), and the shift amount is reduced for an exposure pattern having a small dimension, as shown in FIG. Needs to be increased. Specifically, in the case of a positive resist, an exposure pattern having a relatively large size, for example, when the design pattern width is 0.7 μm, the size may be reduced by about 0.01 μm, but a small size may be used. When the exposure pattern has, for example, a design pattern width of 0.4 μm, the exposure pattern is about 0.
It is necessary to reduce the size by 08 μm. Here, a conventional conversion process of design pattern data into exposure data will be described with reference to FIG.

When the design pattern data is input (step S10), first, the design pattern data is divided into basic figures possessed by an exposure apparatus for performing inversion processing, reduction (enlargement / reduction) processing, field division processing and exposure. Graphic processing such as pattern division processing is performed (step S11). Specifically, assuming that the input design pattern data is as shown in FIG. 8B, basic patterns that can be drawn by the electron beam exposure apparatus as shown in FIG. Divide into P _{11 to} P ₁₅ .

Next, DOS for correcting the exposure amount while considering the mutual influence of the size shift correction for changing the size of each divided basic graphic and each basic graphic after the size shift correction.
Proximity effect correction processing including E amount correction is performed (step S
12) The exposure data is output (step S13). Specifically, the dimension shift is performed for each of the basic figures P _{11 to} P ₁₅ divided by the figure processing, shift figures P ′ _{1 to} P ′ ₅ are obtained as shown by the broken line in FIG. P _'11 ~
The DOSE amount is corrected for each P ′ ₁₅ and is output as the exposure data shown in FIG.

[0008]

In the conventional conversion processing of design pattern data into exposure data described above, after the pattern division processing into basic figures writable by the exposure apparatus is performed, the dimension shift for each basic figure is performed. It was processing. This size shift process is performed as it is in subquark μm
When applied to device exposure, new problems arise that were not a problem in the past. That is, the dimensional shift amounts at the connecting portions of each basic figure with other adjacent basic figures do not always match. Specifically, as shown in FIG. 9 (a), the length should be the same in the connecting portion of the parallelogram F ₁ and the rectangle F ₂ , that is, in the design data (see FIG. 8 (b)). The lengths of the side L ₁ and the side L ₂ do not match because the size shift amounts do not match, and the dimensional accuracy is reduced at the portion where the dimensional accuracy is most required. As described above, uneven portions that are not present in the original design pattern data are generated in the exposure data, and when a high resolution resist is used, the pattern shape is deteriorated (see FIG. 9B) and the reliability is reduced. There was a problem that it would end up.
Particularly, the smaller the design dimension rule is, the larger the required dimension shift amount is (see FIG. 7), so that the degree of shape deterioration when unevenness occurs is large.

Therefore, an object of the present invention is to provide an exposure data conversion processing method and an exposure data conversion device which have high dimensional accuracy and high reliability.

[0010]

In order to solve the above problems, the first aspect of the present invention, as shown in the principle explanatory diagram of FIG. 1, shifts the dimension of the design pattern based on the input design pattern data. When performing the proximity effect, of the multiple dimensions that should be considered at the same time, obtain the dimension shift amount of the dimension that requires the most dimensional accuracy, and perform the dimension shift processing of the multiple dimensions that should be considered at the same time with the obtained dimension shift amount. Dimension shift processing step S100 for performing shift pattern data
And a figure processing step S200 for dividing a figure represented by the shift pattern data into predetermined basic figures, and obtaining exposure amount data for each of the divided basic figures, and further, exposing amount data for each of the basic figures. Exposure amount correction step S300 for determining the exposure data by correcting the exposure amount data in consideration of mutual influences when the exposure based on the above is performed.

Further, the exposure data converter 1 of the second invention.
As shown in the principle explanatory diagram of FIG. 2, 0 is the most of a plurality of dimensions which should consider the proximity effect at the same time when the dimension shift is performed with respect to the dimension of the design pattern by the input design pattern data PD _IN. A dimension shift processing unit 20 that obtains a dimension shift amount of a dimension that requires dimensional accuracy, performs dimension shift processing of the plurality of dimensions that should be considered at the same time with the obtained dimension shift amount, generates shift pattern data SPD, and outputs the shift pattern data SPD. obtains a graphic processing means for outputting a basic figure pattern data PD _F divides the figure represented by the shift pattern data SPD to a predetermined basic diagram exposure amount data for each basic figure pattern data PD _F, and each considering the influence of the basic figure mutually in the case of performing exposure based on the exposure amount data for each basic figure pattern data PD _F by correcting the exposure amount data An exposure amount correction means 40 to output as the exposure data ED, constitutes comprise.

[0012]

According to the first invention, the dimension shift processing step S1.
00 is the dimension shift amount of the dimension that requires the most dimensional accuracy among a plurality of dimensions that should consider the proximity effect at the same time when the dimension shift is performed on the dimension of the design pattern based on the input design pattern data. In the figure processing step S2
00. In the figure processing step S200, the figure represented by the obtained shift pattern data is divided into predetermined basic figures, and the process proceeds to the exposure amount correction step S300. The exposure amount correction step S300 obtains exposure amount data for each divided basic figure, and further corrects the exposure amount data in consideration of mutual influences when exposure is performed based on the exposure amount data for each basic figure. , Obtain exposure data.

Therefore, since the dimension shift processing is performed before the figure represented by the design pattern data is divided into the basic figures, unnecessary unevenness which is not present in the design pattern data does not occur in the exposure data, so that the dimensional accuracy is high. It is possible to obtain reliable exposure data.

According to the second invention, the dimension shift processing means 20 should simultaneously consider the proximity effect when the dimension shift is performed with respect to the dimension of the design pattern according to the input design pattern data PD _IN. Among these dimensions, the dimension shift amount of the dimension that requires the most dimensional accuracy is obtained, and the dimension shift processing is performed for a plurality of dimensions that should be considered at the same time with the obtained dimension shift amount, and shift pattern data SPD is generated
It is output to the graphic processing means 30. The figure processing means 30 divides the figure represented by the shift pattern data SPD into predetermined basic figures and outputs the basic figure pattern data PD _F to the exposure amount correcting means 40. Exposure amount correction means 40
Determines the exposure amount data for each basic figure pattern data PD _F, the exposure data in consideration of the influence of each basic figure mutual when further subjected to exposure the based on the exposure data for each basic figure pattern data The corrected data is output as the exposure data ED.

Accordingly, since the dimension shift processing is performed before the figure represented by the design pattern data PD _IN is divided into the basic figure pattern data PD _F , the exposure data ED has irregularities which are not present in the original design pattern data. It is possible to obtain highly reliable exposure data with high dimensional accuracy.

[0016]

EXAMPLE An example of the present invention will be described with reference to FIGS. FIG. 3 shows a schematic configuration of the exposure data conversion apparatus of this embodiment.

The exposure data converter 1 is provided from the outside by an external storage device 2 such as a magnetic disk device for storing various data such as design pattern data and exposure data, and a design device 6 or a storage medium 7 such as a magnetic tape. A dimension shift processing unit 3 for performing dimension shift processing on the design pattern data PD _{IN and} outputting it as shift pattern data SPD, and a figure processing unit 4 for performing graphic processing on the shift pattern data SPD and outputting it as shift pattern figure data SPF. , Exposure pattern data for each of the shift pattern graphic data SPF, the proximity effect is corrected for the obtained exposure data, and the exposure data is output to the external electron beam drawing apparatus 8 as the exposure data ED. 5, and is comprised.

Next, the operation will be described with reference to FIGS. When the design pattern data PD _IN is input to the exposure data conversion apparatus 1 (step S1), the dimension shift processing unit 3 first performs uniform dimension shift according to the critical dimension (step S2), and FIG.
The shift pattern data SPD indicated by the broken line in (c) is output. For example, as shown in FIG. 5, consider a case where a wiring PATH of 0.5 μm is provided between two areas AREA1 and AREA2 of a square having a side of 10 μm. These two areas AREA
1, AREA2 and wiring PATH need to consider proximity effect at the same time. That is, in consideration of the case where the dimension of the wiring PATH is surely secured and the dimensional accuracy of the areas AREA1 and AREA2 is not so demanded, in this case, the dimension of the wiring PATH is 0.5 μ.
m corresponds to the critical dimension, 0.5 μm
The amount of shift that ensures the wiring PATH of
EA1, AREA2 and the wiring PATH are uniformly set (for example, all have a shift amount of 0.01 μm).

Next, the graphic processing section 4 performs graphic processing on the shift pattern data SPD (step S3). For example, inversion processing such as mirror inversion necessary for exposing a mask or reticle and reduction (enlargement / reduction) processing are performed. Next, in the exposure apparatus such as the electron beam drawing apparatus, since the area (field) in which the exposure can be performed is determined only by scanning the beam, the shift pattern data SPD
Is divided into necessary fields. Electron beam drawing device (exposure device) for further exposure
Design pattern data PD _IN for basic figures that can be drawn with 8
A pattern division process, which is a division of the figure represented by (or shift pattern data SPD), is performed.

When these graphic processes are completed, the graphic processing unit 4 outputs the processed shift pattern data SPD as shift pattern graphic data SPF. For example, the figure represented by the input design pattern data PD _IN is shown in FIG.
As shown in FIG. 4C, a shift pattern figure is obtained by dividing the figure into basic figures P _{1 to} P ₅ which can be drawn by the electron beam drawing apparatus 8 by figure processing as shown in FIG. 4D. Output as data SPF.

Next, the exposure amount correction processing unit 5 is divided into
Basic pattern P which is the shift pattern graphic data SPF₁
~ P_FiveCalculate the actual exposure amount from the area, shape, etc. for each
It Next, the uniform dimensional shift performed in step S2
The basic figure P₁~ P_FiveEach basic figure, considering each
P₁~ P_FiveThe exposure amount is corrected by considering the mutual influence of
DOSE amount correction (step S4)
Output directly to the electron beam drawing device 8 as
Or output to the external storage device 2 for storage (step S
5). That is, as shown in FIG.
Divided basic figure P ₂~ P_FourEach figure before each dimension shift
P ’₂~ P '_FourOn the edge of (for example, the point s₁. ), Center (a
Rui is the center of gravity. For example, the point s₂. ), The vertex (eg, the point s
₃. ) Etc. with sample points to evaluate the exposure dose
The DOSE amount is corrected, and the exposure data shown in FIG.
And output. This DOSE amount correction is performed by, for example, the figure P.
₂If a sample point is provided at the midpoint of the four sides of
Find the exposure at the pull point and find the arithmetic mean of them
It is done by doing things such as.

As described above, according to this embodiment, the uniform dimension shift correction is first performed according to the critical dimension, and the graphic processing is performed thereafter. Therefore, the design pattern data is added to the final exposure data. Since there is no unevenness that is not present in the pattern, it is possible to obtain highly accurate and reliable exposure data from large patterns to sub-quarter μm-order ultrafine patterns, and to form patterns with high accuracy and without shape deterioration. Is possible.

[0023]

According to the first aspect of the present invention, the dimension shift processing is performed before the design pattern data is divided into the basic figures. Therefore, there is no need in the design pattern data due to the different dimension shift amount for each basic figure. It is possible to obtain highly reliable exposure data with high dimensional accuracy without causing irregularities.

According to the second aspect of the invention, since the dimension shift process is performed before the design pattern data is divided into the basic figure pattern data, the exposure data may have irregularities which are not present in the original design pattern data. However, it is possible to obtain highly reliable exposure data with high dimensional accuracy, and it is possible to perform pattern formation with high accuracy and without deterioration of shape using an electron beam drawing apparatus or the like.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the first invention.

FIG. 2 is a diagram illustrating the principle of the second invention.

FIG. 3 is a block diagram showing a device configuration of an embodiment.

FIG. 4 is a diagram illustrating a process of an example.

FIG. 5 is a diagram for explaining the operation of the embodiment.

FIG. 6 is a diagram illustrating an exposure intensity function.

FIG. 7 is a diagram illustrating a dimension shift amount.

FIG. 8 is a diagram illustrating a conventional process.

FIG. 9 is a diagram illustrating a conventional problem. Explanation of reference numerals 1 ... Exposure data conversion device 2 ... External storage device 3 ... Dimension shift processing part 4 ... Graphic processing part 5 ... Exposure amount correction part 6 ... Design device 7 ... Storage medium 8 ... Electron beam drawing device 10 ... Exposure data conversion Device 20 ... Dimension shift processing means 30 ... Graphic processing means 40 ... Exposure correction means S100 ... Dimension shift processing step S200 ... Graphic processing step S300 ... Exposure correction processing step PD _IN ... Design pattern data SPD ... Shift pattern data PD _F ... Basic figure pattern data SPF ... Shift pattern figure data ED ... Exposure data

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01J 37/305 9172-5E

Claims (4)

[Claims] 1. A size shift amount of a size that requires the most size accuracy among a plurality of sizes that should simultaneously consider proximity effects when a size shift is performed on a size of a design pattern based on input design pattern data. And the figure represented by the shift pattern data is determined in advance by the dimension shift processing step (S100) of obtaining the shift pattern data by performing the dimension shift processing of the plurality of dimensions to be considered at the same time with the obtained dimension shift amount. A figure processing step (S200) of dividing into basic figures, and determining the exposure amount data for each of the divided basic figures, and further performing exposure based on the exposure amount data of each of the basic figures. An exposure amount correction step of correcting the exposure amount data in consideration of the influence and obtaining the exposure data (S
300), and an exposure data conversion method comprising: 2. The exposure data conversion method according to claim 1, wherein the exposure amount correction step evaluates the exposure amount on each basic figure when the figure represented by the design pattern data is divided into basic figures. An exposure data conversion method comprising providing a sample point and performing the exposure amount correction based on the exposure amount of the sample point. 3. Design pattern data (P
D _IN ) The dimension shift amount of the dimension that requires the most dimensional accuracy among the multiple dimensions that should be considered for the proximity effect when the dimension shift is performed with respect to the dimension of the design pattern. In the shift pattern data (S
Dimension shift processing means (20) for generating and outputting (PD)
And a graphic processing means (30) for dividing the graphic represented by the shift pattern data (SPD) into predetermined basic graphics and outputting the basic graphic pattern data, and for each of the basic graphic pattern data (PD _F ). The exposure amount data is obtained, and the basic figure pattern data (PD
_F ) an exposure amount correcting means (40) for correcting the exposure amount data in consideration of mutual influences when exposure is performed based on the exposure amount data for each and outputting as exposure data (ED). An exposure data conversion device characterized by the above. 4. The exposure data conversion apparatus according to claim 3, wherein the exposure amount correction means (40) divides the exposure amount on each basic figure when the figure represented by the design pattern data is divided into basic figures. An exposure data conversion apparatus comprising a sample point correcting means for providing a sample point for evaluating, and performing the exposure amount correction based on the exposure amount of the sample point.