JP2019109499A - Pattern drawing method, method for manufacturing photomask, photomask, and method for manufacturing display device - Google Patents

Abstract

To reduce variation of a pattern CD and obtain a stable yield and production efficiency when an electronic device (for example, display device) that is a final product is manufactured.SOLUTION: A pattern drawing method includes: a correction step of correcting design pattern data according to a predetermined correction value so that CD of a hole/dot pattern obtained on a transferred body becomes a target value by exposing a photomask with light to obtain corrected pattern data; and a drawing step of applying the corrected pattern data to perform drawing with the use of a drawing device, in which the drawing device is performed by a driving method such that CD control accuracy is different in an X direction and a Y direction perpendicular to the X direction in a plane parallel to a photomask substrate surface, and the correction step of subjecting the design pattern data to correction that changes the CD of the hole/dot pattern in a direction with high CD control accuracy in the X direction and the Y direction to obtain the corrected pattern data.SELECTED DRAWING: Figure 8

Description

  A photomask for manufacturing an electronic device, which is particularly applicable to a photomask for manufacturing a display device represented by a liquid crystal display panel (LCD), an organic EL display (OLED) or the like The present invention relates to a method of manufacturing a photomask, and a pattern drawing method used in the manufacturing method.

  Patent Document 1 (hereinafter referred to as Document 1) describes a method of performing exposure by correcting a pattern line width change generated in a development stage at the time of manufacturing a photomask. According to this, the step of forming the measurement pattern on the photomask substrate by the test pattern having the predetermined line width, the region on the photomask substrate is divided into meshes, and the line width of the measurement pattern is determined for each mesh. Measuring and determining a pattern line width variation amount ΔCD which is a difference between the measured line width and the line width of the test pattern, and for a mesh having a distance r from an arbitrarily defined reference mesh Creating a graph showing a distribution of the measured pattern line width variation ΔCD (r) with respect to the distance r; and a pattern line at an arbitrary point on the photomask substrate where the distance from the reference mesh is x Predicting the width change amount ΔCD (x) from the graph, and for each point on the photomask substrate, the predicted pattern line width change amount ΔCD (x) Correcting the pattern line width data so as to narrow the pattern line width of the area where the predicted pattern line width variation amount ΔCD (x) is positive; and on the photomask substrate Applying the corrected pattern line width data to each point of the exposure equipment.

Japanese Patent Application Laid-Open No. 2003-107665

  According to Document 1, when manufacturing a photomask for manufacturing a semiconductor device, it is possible to compensate for the change in line width generated at the development stage to improve the uniformity.

  However, according to the inventor's investigation, there are factors that cause the pattern line width (that is, CD) to fluctuate in addition to the line width change of the pattern that occurs in the development stage at the time of photomask manufacturing. For example, in the process of manufacturing a photomask, there is also a CD error caused by a drawing apparatus, or various steps such as exposing a pattern on a transfer target using a photomask, developing a pattern after exposure, etc. In the early stage, there are factors that cause CD change. For this reason, it is not easy to obtain an excellent device (such as a display device) by the exposure of the photomask only by the method of Document 1.

  Therefore, the present invention has completed the present invention with the object of reducing fluctuation of the pattern CD and obtaining stable yield and production efficiency when manufacturing an electronic device (for example, display device) which is a final product. .

(First aspect)
The first aspect of the present invention is
A pattern drawing method for forming a photomask provided with a transfer pattern including a hole / dot pattern by drawing on a photomask substrate based on predetermined design pattern data,
The design pattern data is corrected to obtain correction pattern data according to the correction value obtained in advance so that the CD of the hole / dot pattern obtained on the transfer target by exposing the photomask becomes a target value. A correction process,
Applying the correction pattern data, and performing drawing using a drawing apparatus;
The drawing apparatus is based on a driving method in which the CD control accuracy is different in an X direction and a Y direction perpendicular to the X direction in a plane parallel to the photomask substrate surface.
In the correction step, correction pattern data is obtained by performing correction on the design pattern data to change the CD in the direction with high CD control accuracy in the X direction and the Y direction with respect to the CD of the hole / dot pattern. It is a pattern drawing method characterized in that.
(Second aspect)
The second aspect of the present invention is
In the correction step, a target area of the hole / dot pattern of the transfer pattern is determined such that the CD of the hole / dot pattern obtained on the transfer target is equal to a target value.
Based on the target area of the hole / dot pattern of the transfer pattern, the CD in the X direction and the Y direction of the hole / dot pattern is changed with respect to the CD of the hole / dot pattern with respect to the design pattern data. The pattern drawing method according to the first aspect is characterized in that correction pattern data is obtained by performing correction.
(Third aspect)
The third aspect of the present invention is
A pattern drawing method for forming a photomask provided with a transfer pattern including a hole / dot pattern by drawing on a photomask substrate based on predetermined design pattern data,
The design pattern data is corrected according to the correction value obtained in advance so that the area of the hole / dot pattern obtained on the transfer target by exposing the photomask becomes equal to the target value. The correction process to be obtained,
Applying the correction pattern data, and performing drawing using a drawing apparatus;
The drawing apparatus is based on a driving method in which the CD control accuracy is different in an X direction and a Y direction perpendicular to the X direction in a plane parallel to the photomask substrate surface.
In the correction step, correction pattern data is obtained by performing correction on the design pattern data to change the CD in the direction with high CD control accuracy in the X direction and the Y direction with respect to the CD of the hole / dot pattern. It is a pattern drawing method characterized in that.
(Fourth aspect)
The fourth aspect of the present invention is
In the correction step, a target area of the hole / dot pattern on the transfer target is obtained.
The target area of the hole / dot pattern of the transfer pattern is determined based on the target area of the hole / dot pattern on the transfer target body,
Based on the target area of the hole / dot pattern of the transfer pattern, the CD in the X direction and the Y direction of the hole / dot pattern is changed with respect to the CD of the hole / dot pattern with respect to the design pattern data. The pattern drawing method according to the third aspect is characterized in that correction pattern data is obtained by performing correction.
(Fifth aspect)
The fifth aspect of the present invention is
The drawing apparatus is a laser drawing apparatus for drawing using a laser beam, which is the drawing method according to any one of the first to fourth aspects.
(Sixth aspect)
The sixth aspect of the present invention is
Any one of the above first to fifth features, wherein X-CD and Y-CD of the hole / dot pattern in the transfer pattern are less than the resolution limit dimension of the exposure apparatus that exposes the photomask. The pattern drawing method according to the aspect of
(Seventh aspect)
The seventh aspect of the present invention is
In the pattern drawing method according to any one of the first to fifth aspects, X-CD and Y-CD of a hole / dot pattern in the transfer pattern are less than 3 μm.
(Eighth aspect)
The eighth aspect of the present invention is
In the drawing apparatus, after the laser beam performs a delivery operation with a constant feed width in the X direction, an irradiation operation with a given width in the Y direction is performed, and these operations are alternately repeated to draw on the photomask substrate. It is a pattern drawing method as described in any one of the said 1st-7th aspects characterized by performing.
(Ninth aspect)
The ninth aspect of the present invention is
In the correction process, a CD correction value obtained so that the area of the hole / dot pattern and the area of the hole / dot pattern on the photomask substrate included in the design pattern data are equal to that of the design pattern data The pattern drawing method according to any one of the first to eighth aspects, wherein correction pattern data is obtained by substituting CD.
(Tenth aspect)
The tenth aspect of the present invention is
Prior to the correcting step, obtaining a preliminary mask on which a pattern is drawn using the drawing device;
It is the pattern drawing method as described in any one of the said 1st-9th modes which have a correction value grasping | ascertaining process which grasp | ascertains the said correction value by X-CD and Y-CD of the said preliminary mask.
(Eleventh aspect)
An eleventh aspect of the present invention is a method of manufacturing a photomask, including the drawing method according to any of the first to tenth aspects.
(Twelfth aspect)
The twelfth aspect of the present invention is
A photomask provided with a transfer pattern including a plurality of hole / dot patterns, wherein
The plurality of hole / dot patterns in the transfer pattern have X-CD and Y-CD less than 3 μm,
The plurality of hole / dot patterns in the transfer pattern is a photomask characterized in that it includes a hole / dot pattern group having X-CDs different from one another and having a square shape having the same area as one another.
(13th aspect)
The thirteenth aspect of the present invention is
Providing a photomask according to the manufacturing method according to the twelfth aspect;
It is a manufacturing method of a display including transferring the pattern for transfer on a receiving object using an exposure apparatus whose NA of an optical system is 0.08 to 0.20.
(Fourteenth aspect)
A fourteenth aspect of the present invention is
A method of manufacturing a display device, comprising transferring a transfer pattern of a photomask onto a transfer target by exposing a photomask formed based on predetermined design pattern data.
The design pattern data is corrected to obtain correction pattern data according to the correction value obtained in advance so that the CD of the hole / dot pattern obtained on the transfer target by exposing the photomask becomes a target value. A correction process,
A drawing process of applying the correction pattern data and drawing on a photomask substrate using a drawing apparatus;
Developing and etching the photomask substrate to form a photomask provided with the transfer pattern;
Exposing the photomask with an exposure device to form a hole / dot pattern on a transfer target,
The hole / dot pattern X-CD and Y-CD in the transfer pattern is less than 3 μm,
In the correction step, correction is performed by changing the CD of the hole / dot pattern in the design pattern data in the direction in which the CD control accuracy of the drawing device is high among the X direction and Y direction. It is a manufacturing method of a display characterized by obtaining pattern data.
(Fifteenth aspect)
According to a fifteenth aspect of the present invention,
Prior to the correcting step, obtaining a preliminary mask provided with a preliminary transfer pattern drawn using the drawing apparatus;
A fourteenth aspect having a correction value grasping step of grasping the correction value by the CD of the hole / dot pattern formed on the transfer object by exposing by the exposure device using the preliminary mask It is a manufacturing method of a display given in a.
(The sixteenth aspect)
The sixteenth aspect of the present invention is
A method of manufacturing a display device, comprising transferring a transfer pattern of a photomask onto a transfer target by exposing a photomask formed based on predetermined design pattern data.
The design pattern data is corrected according to the correction value obtained in advance so that the area of the hole / dot pattern obtained on the transfer target by exposing the photomask becomes equal to the target value. The correction process to be obtained,
A drawing process of applying the correction pattern data and drawing on a photomask substrate using a drawing apparatus;
Developing and etching the photomask substrate to form a photomask provided with the transfer pattern;
Exposing the photomask with an exposure device to form a hole / dot pattern on a transfer target,
The hole / dot pattern X-CD and Y-CD in the transfer pattern is less than 3 μm,
In the correction step, correction is performed by changing the CD of the hole / dot pattern in the design pattern data in the direction in which the CD control accuracy of the drawing device is high among the X direction and Y direction. It is a manufacturing method of a display characterized by obtaining pattern data.

  By applying the present invention, correction of design pattern data used for drawing a photomask is properly performed, and a substrate to be transferred (that is, a process for manufacturing a device) is exposed by exposing the corrected photomask. CD accuracy of the transferred image obtained on the body) is improved.

FIG. 1 (a) is a schematic plan view of a binary mask having a hole pattern, and FIGS. 1 (b) and 1 (c) show the CD error on the mask in the X direction with respect to the design dimension of the square hole pattern. It is a figure which measured and plotted about CD of the Y direction perpendicular | vertical to it and it. FIG. 2 is a view schematically showing the beam feeding operation of the laser drawing apparatus. FIG. 3 is a diagram showing a state of CD control of a pattern in the Y direction. FIG. 4 is a view showing a state of CD control of a pattern in the X direction. FIG. 5 is a view showing a mask pattern to be simulated. 6 is a space image formed on the transfer target when the mask pattern shown in FIG. 5 is exposed, which is virtually cut at a position corresponding to a broken line shown in each pattern of FIG. It is a space image on the body. FIG. 7 is a diagram showing the amount of fluctuation of X-CD in a transferred image when X-CD and Y-CD are changed with respect to a hole pattern of each size. FIG. 8 is a diagram showing the results of optical simulation.

  At present, in the field of display devices, there is a strong demand for finer pixels and higher integration of pixels, and it is desired to improve display performance such as high-speed display and wide viewing angle while being brighter and saving power. .

  For example, in the case of thin film transistors ("TFTs") used in the above display device, the contact holes formed in the interlayer insulating film among the plurality of patterns constituting the TFT can surely be patterns of the upper layer and the lower layer. The correct operation can not be guaranteed without the function of connecting the On the other hand, for example, in order to increase the aperture ratio of the liquid crystal display as much as possible to make it a bright, power-saving display, it is required that the diameter (CD) of the contact hole be sufficiently small. With the demand for densification, it is also desired to miniaturize the hole pattern diameter (for example, less than 3 μm). For example, a fine hole pattern having a diameter of 0.8 μm or more and less than 3 μm is required, and a technique for stably and efficiently forming the same is required.

  By the way, in the field of photomasks for manufacturing semiconductor devices (LSI), in which the degree of integration is high and the miniaturization of patterns is remarkably advanced as compared with display devices, in order to obtain high resolution, high openings are provided in exposure devices. The optical system of several NA (for example, more than 0.2) is applied, and the shortening of the wavelength of exposure light has been promoted. As a result, in this field, KrF and ArF excimer lasers (248 nm and 193 nm single wavelengths, respectively) have been used. An EB (electron beam) drawing apparatus has also been adopted as a drawing apparatus for manufacturing a photomask.

  On the other hand, in the field of lithography for display device manufacturing, it has not been common for the above-described method to be applied to improve resolution. For example, the NA (numerical aperture) of the optical system of the exposure apparatus used in this field is about 0.08 to 0.2. In addition, i-line, h-line, or g-line are frequently used as exposure light sources, and a broad wavelength light source mainly including these is used to make a photomask with a large area (for example, a square with a side of 300 to 2000 mm). There is a strong tendency to focus on production efficiency and cost by obtaining the amount of light for irradiation.

Under these circumstances, also in the manufacture of display devices, as described above, the demand for finer patterns has become higher. Here, there are some problems in applying the technology for manufacturing a semiconductor device as it is to manufacturing a display device. For example, conversion to a high resolution exposure apparatus having a high NA (numerical aperture) has technical difficulties and requires a large investment. In addition, when the exposure wavelength is changed (for example, a short wavelength such as ArF excimer laser is used at a single wavelength as in the semiconductor device manufacture), the production efficiency decreases if it is applied to a display device having a large area. Besides, it is inconvenient in that it also requires a considerable investment. That is, it is a problem of the photomask for display device manufacturing that the cost and efficiency which are the existing merits can not be lost while pursuing the miniaturization of the pattern which is not in the past.
Exposure devices for manufacturing display devices often have a limit dimension of a resolvable pattern (for example, a hole pattern) of about 3 μm. However, as a photomask for manufacturing display devices, the size is close to this, or this There are cases where a hole / dot pattern with a CD less than 3 μm is required. Therefore, there is a need for a method of finely transferring even a fine CD which the exposure apparatus does not guarantee.

[Necessity of CD correction]
In manufacturing a display device, it is strongly required to stably form a hole pattern or a dot pattern having a small CD (Critical Dimension, hereinafter referred to as a pattern width) in a desired size. On the other hand, by exposing the photomask, the dimensions of these patterns formed on a transfer target (such as a display panel substrate) do not become as designed, and there are several factors that cause variations.

  For example, in the photomask manufacturing process, the hole pattern or dot pattern CD included in the photomask may deviate from the design value.

  Hereinafter, although the case where a hole pattern is mainly formed will be described as an example, the present invention can be applied not only to a hole pattern but also to a dot pattern. Related to this, in the present application, the “hole pattern or dot pattern” is simplified and also referred to as “hole / dot pattern”.

  In the manufacture of a photomask, first, based on the design of a device (display device or the like) to be obtained, the photomask is designed to create pattern data for drawing (design pattern data). Then, using this data, drawing is performed on the photomask substrate using a drawing apparatus. The photomask substrate may be a photomask blank in which an optical film (such as a light shielding film) for forming a photomask pattern and a resist film are formed on a transparent substrate, or one of laminated optical films. It may be a photomask intermediate in which an optical film or a resist film is formed to perform further patterning after patterning the part. These drawn photomask substrates are sent to the developing step. By patterning the optical film using the resist pattern formed by development as an etching mask, a photomask provided with a transfer pattern can be obtained. Ideally, the design of the photomask obtained should be a faithful reflection of the design pattern data, and the pattern CD on the photomask should be as shown in the design pattern data .

  However, with the miniaturization of patterns to be handled, when the CD of the obtained photomask is measured, deviation from the CD due to the design pattern data may occur. There are various causes as this cause, for example, when there are individual differences in output among a plurality of laser beams divided from a laser oscillator, which are provided in a drawing apparatus, or slight variations occur in driving of a laser head. However, this includes CD errors that occur with the same tendency with reproducibility.

  In such a case, preliminary drawing is performed using predetermined design data, a preliminary mask is created, and CD measurement of the formed transfer pattern is performed to grasp the tendency of CD errors and reflect the same. Then, if the design pattern data of the photomask to be actually obtained is corrected, it is considered that a photomask as designed can be obtained (Case 1: Case of Mask CD Malfunction).

  Furthermore, when pattern transfer is performed on a transfer target (such as a display panel substrate) using an exposure apparatus using a photomask, there may be a case where an error from the target CD occurs in the obtained transfer image. is there. Such a case may occur even when a CD error does not occur in the transfer pattern provided in the photomask used (Case 2: Case of Panel CD Malfunction).

  As a cause of Case 2, for example, when in-plane distribution occurs in the film thickness of the resist film formed on the transfer-receiving material before exposure, or in-plane variation occurs in supply of the developer in the process of development For example, depending on the position on the transfer medium, there may be variations in CDs that should be the same. In particular, the substrate (mother glass etc.) for display devices has a large size (one side is more than 1000 mm to 3000 mm, etc.), and the in-plane processing conditions depend on the structure of the resist coating device and developing device and the liquid flow of wet processing. Unevenness is completely inevitable.

  Furthermore, in the exposure apparatus used to expose the photomask, the light quantity distribution in the plane may occur due to the apparatus configuration.

  Even if the processing conditions described above and the in-plane non-uniformness of the exposure conditions are used, as long as the same apparatus is used, this tendency is grasped for CD errors that appear with reproducibility, and measures are taken to reduce this. It is considered possible to reduce the impact. Specifically, the CD non-uniformity of the transferred image, which is caused by these in-plane non-uniformity factors, is reflected in advance on the pattern data of the photomask, and the tendency of CD increase or decrease caused by the non-uniformity. It can be assumed that it is effective to make a correction to offset the

[On the difficulty of CD correction]
Therefore, for example, in the photomask manufacturing process, CD errors caused by the drawing apparatus are considered. If CD measurement of a preformed photo mask is performed and this CD is different from the CD by the design pattern data, it should be possible to correct the CD of the design pattern data in order to offset the CD error in advance . For example, based on the result of CD measurement of a photomask, if the X-CD (CD in the X direction) of the hole pattern on the photomask is too large, correction that reduces the X-CD of the corresponding hole pattern in the design pattern data If Y-CD (CD in Y direction) is too small, it is considered that correction may be performed to increase the corresponding Y-CD in the design pattern data. However, according to the inventor's study, such correction of design pattern data has resulted in the case where a satisfactory result can not always be obtained.

[Difference in controllability of X-CD and Y-CD by drawing]
Hereinafter, a photomask having a hole pattern as a transfer pattern will be described as an example. The hole pattern (also referred to herein as a mask hole pattern) possessed by the photomask is usefully used, for example, as a transfer pattern for forming a contact hole on a transfer target. And in this pattern, the trend of miniaturization is remarkable because of the recent high definition display device.

  On the other hand, as a fine CD, for example, a pattern having a dimension smaller than the resolution limit dimension of an exposure apparatus used for exposing a photomask may be mentioned. There are many cases where display devices having such fine patterns are produced. If a pattern with such a CD is formed, difficulties in the manufacture of a photomask also arise, and it is difficult to form a pattern with the exact dimensions as designed on the photomask.

The resolution limit dimension R of the exposure apparatus is defined by the following equation.
R = k × (λ / NA)
The coefficient k is a constant, which is 0.61 here. Also, λ is the wavelength of light used for exposure. For example, in the case of using light including a plurality of wavelengths such as i-line, h-line, and g-line (also referred to as broad wavelength light), an average value (weighted average in consideration of light intensity of the included wavelength) is used. Alternatively, λ can be simply set to the representative wavelength (for example, i-line). Further, NA is the numerical aperture on the mask side of the projection optical system of the exposure apparatus.

  As described above, as the background for which it is difficult to form the transfer pattern as designed in the process of manufacturing the photomask, the CD accuracy for the drawing apparatus used when drawing the pattern has a margin for the CD accuracy along with the tendency of pattern miniaturization. It is related to being gone.

  Therefore, we verified the CD accuracy of the photomask. Here, in the case where a square hole pattern (punched pattern) is to be formed on a photomask in order to form a hole pattern on a transfer target, its CD controllability was examined.

  A Cr-based light shielding film was formed on a substrate made of a transparent material, and a photomask blank having a positive photoresist film formed on the surface was prepared. Then, using a laser drawing apparatus, a plurality of square hole patterns each having a design dimension W1 (μm) were drawn. Here, W1 was gradually decreased from 5.5 μm to about 1.0 μm.

  After drawing, the resist is developed to form a resist pattern, and the light shielding film is wet-etched using the resist pattern as a mask to form a binary mask having a hole pattern on the photomask substrate (FIG. 1A). ) Was produced.

  Next, the size of the hole pattern of the formed binary mask was measured. That is, the CD errors on the mask measured for the X-direction and the Y-direction CD perpendicular thereto (referred to as X-CD and Y-CD, respectively) with respect to the square hole pattern design dimensions, It is FIG.1 (b) and (c).

  As shown in FIGS. 1 (b) and 1 (c), as the CD as a design size decreases from 5.5 μm, the errors of the binary mask X-CD and Y-CD change to the negative side, and further, the design CD is 3 μm. From below, the absolute value of the CD error amount of the binary mask rapidly increases.

  On the other hand, the above behavior is different between X-CD and Y-CD. While the change in the error amount of Y-CD draws a smooth curve, irregular changes are observed in the change in the error amount of X-CD. It can be understood that the change in the amount of error in X-CD is unstable and difficult to predict as compared with Y-CD.

  The drawing apparatus used at this time is a laser drawing apparatus, and after the laser beam performs an operation of sending a fixed feed width in the X direction, an irradiation operation of a fixed width is performed in the Y direction, and these operations are alternately repeated. Thus, drawing is performed on the photomask substrate. That is, it was found that the CD accuracy of the pattern formed on the photomask had a difference in CD controllability in the X direction and in the Y direction depending on the drive mechanism of the drawing apparatus.

  FIG. 2 schematically shows the beam feeding operation of the drawing apparatus. Here, a laser beam of a predetermined beam diameter (in this case, a single-beam drawing machine is shown) is sent out in the X direction with a predetermined feed width, and thereafter, while repeating an operation of scanning in the Y direction with a predetermined width, The drawing shows how to draw in the entire drawing area. Note that these operations may be performed only by the movement of the head that emits a laser beam, or may be realized by the movement of the relative position to the movement of the stage on which the photomask substrate is mounted.

  The state of CD control of the pattern in the X and Y directions is shown in FIGS. The Y-CD of the pattern can be controlled by turning the beam on and off (Figure 3). On the other hand, X-CD is controlled by the array width of the beam (and, if necessary, the power adjustment of the end beam) (FIG. 4). That is, since the control method of X-CD and Y-CD is different, a difference also arises in control accuracy. When considered together with the results of (b) and (c) of FIG. 1, in this drawing apparatus, the accuracy of control of Y-CD is higher than control of X-CD, and CD correction is performed on pattern data It is possible to estimate that the target correction value is reflected on the drawing with good reproducibility, and a predetermined effect is obtained.

  Further, in the above, after the laser beam performs a delivery operation with a constant feed width in the X direction, laser irradiation is performed while scanning with a given width in the Y direction, and drawing is performed by alternately repeating these operations. Although the drawing apparatus has been described, it is not necessarily limited to this method. For example, the irradiation operation involves an operation (scan irradiation) of turning on / off the irradiation while scanning an area of a fixed width extending in the Y direction, as well as power adjustment to the area of the fixed width. It may be an operation of simultaneous irradiation (shot irradiation). Further, the present invention described later can be applied as long as the effects of the present invention can be obtained even with other energy beams (for example, LEDs) without being limited to the laser.

  Furthermore, although the single beam has been described above, the CD control accuracy may sometimes differ between the X direction and the Y direction even in a drawing apparatus that performs drawing by operating a plurality of (multi) beams. Of course, the invention is also applicable in the case.

[Correlation between CD on Photomask and CD on Transferred Body]
By the way, if the pattern CD formed on the transfer target shows a non-uniform CD error in the plane, appropriate CD correction in pattern data for manufacturing a photomask for each pattern having a CD error Methods may be employed to eliminate this disadvantage. Therefore, when X-CD and Y-CD of the photomask are changed by a predetermined amount, what will be the spatial image (light intensity distribution) formed on the transfer target, and on the transfer target Optical simulation was conducted to examine how the CD of the transferred pattern changes.

  FIG. 5 shows a mask pattern to be simulated. In general, when forming a hole pattern such as a contact hole on a material to be transferred, the shape of the mask hole pattern is square. Here, a resist on the transfer target is a positive type, and a photomask having a square cutout pattern (A) is prepared, and the diameter (length of one side) is 10.0 μm (Reference Example 1), It was 2.0 μm (Reference Example 2).

  (B) is obtained by increasing X-CD by 0.025 μm with respect to the two square patterns (A) described above (referential examples 3 and 4 respectively).

  (C) is obtained by increasing Y-CD by 0.025 μm with respect to the above two square patterns (A) (respectively, reference examples 5 and 6).

  In FIG. 5, X and Y indicate directions perpendicular to each other in the photomask plane, and have nothing to do with the X and Y directions relating to the drive system of the drawing apparatus described with reference to FIGS.

The applied simulation conditions are as follows.
Optical system of exposure apparatus: NA = 0.08, coherent factor σ = 0.7
The exposure wavelength is broad wavelength light including g-ray, h-ray and i-ray, and the intensity ratio is g: h: I = 1: 1: 1.

  An aerial image formed on the transfer target when the mask pattern shown in FIG. 5 is exposed is shown in FIG. This space image is a space image on the transfer body virtually cut at a position corresponding to the broken line shown in each pattern of FIG.

  The following points become clear from FIG. When the CD is relatively large (FIGS. 6A and 6B), the change of the CD on the mask is relatively faithfully reflected in the aerial image on the transferee. Here, the increase in X-CD of the mask appears as an increase in CD in the X direction in the aerial image (light intensity distribution). The increase in Y-CD on the mask does not affect the CD in the X direction of the aerial image.

  On the other hand, when the absolute value of the hole CD becomes smaller and becomes smaller than the resolution limit dimension of the exposure apparatus (FIG. 6 (c) (d)), the Y-CD increases even if the X-CD is increased on the mask. Also, in the aerial image that appears, the CD in the X direction increases almost as well. In this case, the aerial image on the transfer body is seen to be more correlated to the area of the hole pattern than the dimensions of X-CD and Y-CD of the hole pattern on the mask. In other words, hole patterns with the same area are predicted to draw substantially the same spatial image, whereby the CD of the hole / dot pattern obtained on the transfer target is also approximately the same unless factors other than the photomask are added. It can be expected to be the same.

  At this time, since the transferred image formed on the transfer-receiving material is generated to such an extent that the influence of light diffraction can not be ignored, even if it is a square pattern on the mask, the corner becomes rounded and approaches a circle. Therefore, at this level of fine CD, the CD of the transferred hole pattern becomes less meaningful to distinguish between X-CD and Y-CD, and becomes close to the diameter of the approximate circle. In this case, an average value of X-CD and Y-CD of the hole / dot pattern formed on the transfer target may be simply referred to as CD.

  This phenomenon can be more clearly understood according to FIG. Here, X-CD only (on the left side of the bar graph) is a square (X-CD = Y-CD) hole pattern with respect to a photomask having six types of hole patterns of 1.5 to 10 μm on one side. When a correction of adding 0.025 μm to Y-CD alone (right side of the bar graph) is performed, the X-CD fluctuation amount of the hole pattern formed on the transfer target is shown. Here, as X-CD and Y-CD become smaller, the amount of irradiation light of the exposure light is increased accordingly to obtain a target CD (here, 1.5 to 10 μm as in the case of the photomask). The hole pattern of each CD is formed.

  In FIG. 7, X and Y indicate directions perpendicular to each other in the plane of the photomask and in the plane of the transfer target, and relate to the driving method of the drawing apparatus described in FIGS. It has nothing to do with the direction of Y.

  According to this, when the CD is relatively large, the correction of the X-CD on the mask is reflected on the X-CD on the transfer target, while the X-CD on the mask is reduced as the CD is miniaturized. Both the correction to the CD only and the correction to the Y-CD only cause the change of the X-CD on the transfer medium. In particular, when the CD is less than 3 μm, this tendency becomes remarkable, and when it is 2 μm or less, both the correction of X-CD on the mask and the correction to Y-CD It can be seen that the effect on CD is almost the same. Also, here, the amount of CD change in the transferred image is large beyond the amount (0.025 μm) corrected by X-CD. This means that as the pattern becomes finer, the CD difference on the mask is affected by the phenomenon that the CD difference on the transfer body expands (MEEF-Mask Error Enhancement Factor-increase).

  From the above, it can be seen that, when correcting design pattern data of a photomask, it is not necessary to equally distribute the correction amount to X-CD and Y-CD and to form a square pattern as before correction. Further, it is apparent from the findings in FIG. 1 that it is rather advantageous to correct in the direction in which the controllability of the CD accuracy is good (the direction of Y-CD according to the drawing apparatus). This is because, as judged from the drawing accuracy of X-CD, the reproducibility is low even for CD errors, and there is a risk that a new CD error will occur after the correction when X-CD correction is performed. In consideration of this point, it is desirable not to perform correction on X-CD, but to improve the CD accuracy of the transferred image on the transfer body by correcting only Y-CD as much as possible.

As a result, the correction pattern data is different from X-CDs (Y-CDs are constant) as a result of performing CD correction only in the direction with high drawing accuracy in addition to uncorrected square patterns. , Y-CDs are different from each other (X-CDs are constant), and pattern data of a plurality of squares (rectangles) are included.
Then, drawing is performed using this correction pattern data, and the obtained photomask includes a group of hole / dot patterns having the same area even though the shapes are different from each other. That is, one or more combinations of square hole / dot patterns having different X-CDs (and thus Y-CDs) and equal areas are included, and this is also referred to as a hole / dot pattern group of the same area.

  From this result, the following was found. That is, when performing correction of a CD with respect to a design pattern of a photomask, only one of X-CD and Y-CD, which has higher control accuracy of CD, is taken into consideration in consideration of the structure of a drawing device. It is effective to make corrections. By this method, it is possible to obtain a hole / dot pattern group having the same area with the required area on the photomask, and by exposing the photomask, the designed CD is obtained on the transfer medium. It is easy to obtain the correction effect for obtaining the hole / dot pattern.

Here, the CD having the higher controllability of the CD can be determined by grasping the tendency of the controllability of the drawing apparatus in advance.
Although CD control in the drawing apparatus for photomasks is not necessarily limited to those described in FIGS. 3 and 4, in the drawing apparatus in which a difference in control accuracy occurs between X-CD and Y-CD, The same considerations as above are possible.

  As a more quantitative judgment method in the direction of high CD controllability, in the curves shown in (b) and (c) of FIG. 1, a drop in the amount of CD error in the negative direction can not be seen. The standard deviation of the amount of CD error can be calculated for each of the designed dimensions, and the smaller the standard deviation, the higher the controllability can be. In FIG. 1, the standard deviation in the Y direction (FIG. 1 (c)) is clearly small.

  In addition, the least squares fitting is performed using the approximate curve for the CD error amount in each design dimension, and the standard deviation of the difference between the approximate curve and the CD error amount is calculated, and It may be high.

Such correction method is applied to a fine pattern in which the mask pattern X-CD or Y-CD (preferably X-CD and Y-CD) approaches the resolution limit dimension R of the exposure apparatus. Especially effective. In a projection exposure apparatus for manufacturing a display device, the resolution limit dimension R is generally as follows.
R = k * λ / NA
Here, 0.061 can be applied to the k value. In addition, since the value of NA can be set to 0.08 or more (more specifically, 0.08 to 0.2), approximately 3.0 μm is considered as the resolution limit dimension, and Less than 3.0 μm can be treated as less than the resolution limit. In the future, when the value of NA is improved (for example, when it becomes about 0.1 to 0.2), the value of R also changes, so the CD of the hole / dot pattern to which the present invention is applied may change. However, the approach of the invention is equally applicable.

For example, in the above example, since the control accuracy of the Y-CD of the drawing apparatus is higher than that of X-CD, it has a hole / dot pattern of the required area by correcting only the Y-CD of the mask pattern. It is preferable to use a photomask. The area required here is an area required as a hole / dot pattern on a photomask in order to form a hole / dot pattern having a desired CD on a transfer target.
When Y-CD alone is corrected to obtain the required area, if the value of Y-CD exceeds the above R (for example, 3.0 μm), make Y-CD less than R, Only the shortage of CD to fill the required area may be compensated by the correction of X-CD.

  Specifically, it is preferable to apply the present invention to a photomask for manufacturing a display device, in which X-CD and Y-CD of a transfer pattern formed on the photomask are less than the above R, In addition, when the transfer pattern has a hole / dot pattern, the present invention can be advantageously applied. As a specific example, the effect is remarkable when X-CD and Y-CD are less than 3 μm. Moreover, it is preferable that X-CD and Y-CD are 0.8 micrometer or more. More preferably, X-CD and Y-CD are 1.0 to 2.5 μm, more preferably 1.5 μm to 2.5 μm.

  Using such a transfer pattern, it is possible to obtain a transferred image of about 1.0 to 4.0 μm in CD (X-CD and Y-CD) on a transferee. In other words, the present invention can be suitably applied when the CD of the hole / dot pattern to be obtained on the transfer target is 1.0 to 4.0 μm.

  Further, a preferable range of the correction width (increase / decrease amount) when correcting X-CD or Y-CD is about ± (0.01 to 0.15) μm. If the correction width is excessively large, the correlation accuracy between the pattern area on the photomask and the spatial image on the transfer target may be reduced. If the correction width is excessively small, the merit of correction may not be obtained sufficiently. Within the above range, the dimensional correction of the mask is more precisely performed, and the pattern accuracy obtained on the transfer target can be made closer to a desired value. More preferably, the correction range is ± (0.01 to 0.10 μm).

Example 1
FIG. 8 shows the result of the optical simulation.

  FIG. 8C shows the case where a photomask having a square hole pattern is exposed because both the X-CD and the Y-CD form a hole pattern of 2.5 μm on the transfer target (panel). Suppose. Here, as for design pattern data for drawing, as for X-CD and Y-CD, all are 2.5 micrometers. Then, it is assumed that hole patterns of the same dimensions are formed on the photomask.

However, it is assumed that X-CD fluctuates in the range of 2.4 to 2.6 μm in the hole pattern of the obtained photomask (referred to as a preliminary mask) due to the accuracy of the drawing apparatus. At this time, this preliminary mask is exposed, and X-CD and Y-CD of the optical image formed on the transfer body are plotted as shown in FIG. 8C. The preliminary mask is provided with a preliminary transfer pattern drawn using a drawing apparatus.
In each graph of FIG. 8, the abscissa represents the X-CD fluctuation amount on the photomask, and the ordinate represents the X-CD (dotted line) and Y-CD (solid line) in the optical image formed on the transfer target. Indicates the amount of fluctuation.

  In FIG. 8C, although only the X-CD fluctuates on the preliminary mask, X-CD and Y-CD of the optical image formed on the transfer target are on the preliminary mask. In the same manner, it fluctuates between about 2.35 and about 2.6 μm with the fluctuation of X-CD of.

Next, the design pattern data is corrected. Specifically, the square area (2.5 × 2.5 = 6.25 μm ² ) of the hole design value of 2.5 μm is calculated, and the X-CD of the design pattern data is not changed (design value Y-CD which has the above-mentioned area is determined by X-CD of the hole pattern actually formed on the preliminary mask and X-CD = 2.5 μm), and Y-CD of the design pattern data is obtained. To obtain correction pattern data (correction step). Then, a photomask is formed using the correction pattern data thus obtained.

For example, when a hole pattern of 2.400 μm in X-CD and 2.500 μm in Y-CD is formed on the preliminary mask, this area is 6.000 μm ² . However, it is desirable to obtain a hole pattern having an area of 6.25 μm ² on a photomask. Therefore, X-CD (= 2.50 μm) of the design pattern data corresponding to the hole pattern on this preliminary mask is not changed, while Y-CD of the design pattern data is corrected to 2.604 μm. . Then, drawing is performed by the drawing apparatus (drawing process).

  The obtained photomask is as designed pattern data, and in addition to the hole pattern of uncorrected square (X-CD = Y-CD = 2.5 μm), Y-CD is changed according to the fluctuation of X-CD. It will have a corrected, rectangular hole pattern. These hole patterns are different from X-CD and Y-CD in design pattern data, but equal in area. In addition, holes / dot patterns having the same X-CD and Y-CD as design pattern data have the same area on the photomask. That is, here, the correction pattern data is obtained by replacing the CD correction value obtained so as to equalize the area in the transfer pattern formed on the photomask with the CD of the design pattern data.

  In addition, when this photomask is exposed and the transfer pattern is transferred onto the transfer target body, in the optical image, X-CD and Y-CD are almost constant CD (2.5 μm ± 0.05 μm) A hole pattern is obtained (FIG. 8 (d)). It can be seen that, using this method, it is possible to stably form a hole pattern having a certain dimension and a target dimension on the transfer target. This is because it is within the tolerance of ± 0.1 μm (more preferably ± 0.05 μm) with respect to the target CD to be obtained for the transfer target.

  The target CD of the hole / dot pattern to be formed on the transfer target and the X-CD and Y-CD on the photomask may not necessarily be equal. In the present application, design pattern data indicates dimensions on a photomask. As required, a predetermined bias value is added (or subtracted) to a target CD of a pattern to be formed on a transfer target to form design pattern data of a photomask, which is used as the design pattern data of the above-mentioned design pattern data. It may be X-CD or Y-CD.

On the other hand, in FIGS. 8A and 8B, assuming that a square hole pattern of 4.0 μm in both X-CD and Y-CD is used as design pattern data (Reference Example 7), the same as the above Shows the case where the operation of. When the X-CD on the photomask fluctuates by a width of 3.9 to 4.1 μm and the Y-CD remains at the design value, the X-CD and Y of the optical image formed on the transfer target -CD is shown in Fig. 8 (a).
Also, the square area of 4.0 μm of the hole design value is calculated, and the X-CD of the design pattern data is not changed (with the design value of X-CD = 4.0 μm) and the preliminary mask Y-CD which becomes the above-mentioned area is calculated by X-CD of a hole pattern actually formed in the above, and Y-CD of design pattern data is corrected. Then, a photomask is formed using the correction pattern data thus obtained. The X-CD and Y-CD of the optical image on the transfer body obtained using this photomask are shown in FIG. 8 (b).

  However, at this size (larger than the resolution limit dimension of the exposure apparatus), X-CD and Y-CD of the optical image formed on the transfer target by exposing the photomask are compared with those in Example 1 above. The variation from the design value of 4.0 μm is large.

  From the above, in a photomask having a CD smaller than the resolution limit dimension of the exposure apparatus, a method for obtaining correction pattern data in the case of correcting the hole / dot pattern obtained on the photomask (corresponding to case 1 above) is considered Do.

In the design pattern data of the photomask, X-CD is Xm (des), Y-CD is Ym (des), and area is Sm (des),
The actual X-CD in the formed preliminary mask is Xm (act), Y-CD is Ym (act), and the area is Sm (act),
Assuming that X-CD in correction pattern data is Xm (cor), Y-CD is Ym (cor), and area is Sm (cor)
Ym (cor) = {Sm (des) / Sm (act)} * Ym (act) (1)
It can be done. Here, Xm (cor) = Xm (des).

  That is, when correcting the malfunction of the mask CD, the area of the hole / dot pattern in the design pattern data is maintained to correct the CD in the direction of high CD controllability (here, Y-CD), and the correction pattern Form the data. The resulting transferred image is almost identical to that targeted by the design pattern data.

  In the process of grasping the correction value, the correlation between the area of the hole / dot pattern included in the design pattern data for the preliminary mask used to obtain the preliminary mask and the hole / dot pattern formed on the preliminary mask is calculated. By grasping, it is possible to determine the correction amount of CD (here, Y-CD). Of course, since the area of the hole / dot pattern and the numerical values of X-CD and Y-CD are correlated, in order to obtain the value of equation (1) as a result, at the stage of calculating the correction value Any value may be calculated in any order.

(Example 2)
Based on the design of the pattern to be obtained on the transfer target, design pattern data of a photomask is formed, and based on this, a photomask having a transfer pattern is formed, and this is formed using an exposure apparatus. When transferring, it is assumed that the CD obtained on the transfer target deviates from the target value (case 2). Also in this case, X-CD and Y-CD in the transfer pattern are smaller than the resolution limit dimension of the exposure apparatus.

  Also in this case, this deviation is fed back to the photomask manufacturing process so that the CD of the transfer image formed on the transfer target matches the target value, and the newly corrected photo is used using the correction pattern data. You just have to prepare a mask. And the deviation from the target value of the CD may be due to the deviation of the CD of the photomask, due to the process of exposure, or due to both.

  Also in this case, in the creation of the correction pattern data, the correction of the CD does not change the values of X-CD and Y-CD equally, but the one with higher CD control accuracy (here, Y-CD). Correction pattern data is obtained by changing the value of.

  First, prepare a preliminary mask. The preliminary mask is manufactured by a drawing process using preliminary design pattern data.

Here, in the design pattern data of the photomask, X-CD is Xm (des), Y-CD is Ym (des), and an area is Sm (des),
Let Xp (tar) be the target X-CD of the pattern to be obtained on the transfer target, Yp (tar) be Y-CD, and Sp (tar) be the area,
The actual X-CD in the formed preliminary mask is Xm (act), Y-CD is Ym (act), and the area is Sm (act),
The preliminary mask is exposed by the exposure device, and the X-CD of the transferred image obtained on the transfer target is Xp (act), Y-CD is Yp (act), and the area is Sp (act).
In the correction pattern data, X-CD is Xm (cor), Y-CD is Ym (cor), and area is Sm (cor).

  Here, Sp (tar) is preferably obtained in advance from Xp (tar) and Yp (tar), and a pattern shape (such as a circle or an ellipse).

At this time, Sm (cor) is determined by the following relational expression.
Sm (cor) = Sm (act) * {Sp (tar) / Sp (act)}

Next, correction pattern data to satisfy this Sm (cor) is determined. That is, since the pattern on the mask is square,
Ym (cor) = Sm (cor) / Xm (act)
Here also, Xm (cor) remains Xm (des).

  That is, when the CD of the pattern formed on the transfer target has a deviation from the target value, the required area on the mask necessary to obtain the target area obtained from the target CD on the transfer target is determined. Based on this, CD in the direction of high CD controllability (here, Y-CD) is corrected to form correction pattern data.

  In addition, when the influence of MEEF can not be ignored as the pattern is miniaturized, the coefficient according to the value of MEEF may be applied to the correction amount obtained above.

  In the above description, although the case of forming the hole pattern on the transfer target body is taken as an example, it goes without saying that the same method may be applied to the dot pattern.

  In actual design pattern data, a plurality of hole / dot patterns, which are the same hole / dot pattern, are arranged on a transfer target (panel). In order to obtain the correction pattern data of the present invention, it is preferable to perform the above calculation for each individual hole / dot pattern. The cause of the CD deviation is that it may differ individually depending on the position in the photomask surface and the like.

  In the second embodiment, as in the first embodiment, the same result may be obtained even if the order of calculation is not the same.

  The present invention is not limited to Example 1 and Example 2 described above.

  The present invention also includes a photomask manufacturing method to which the above-described drawing method is applied.

  The present invention also includes a method of manufacturing a display device, including transferring the transfer pattern onto the transfer target using the photomask manufactured in this manner. Here, the display device includes a device for a display device to be incorporated into the display device as a final product.

  As an exposure apparatus, it is useful to use a projection-type equal-magnification exposure apparatus having an optical system with a numerical aperture NA of 0.08 to 0.20 and a coherent factor σ of about 0.2 to 0.7. What is mainly known as an exposure apparatus for FPD can be applied. The exposure wavelength is preferably any one of i-line, h-line and g-line, and broad wavelength light including all of them may be used.

  The transfer pattern may be transferred to a positive resist on a transfer target, or a negative resist may be used. Further, the resist on the transfer target may be a resist pattern as an etching mask, or may be transferred to a photosensitive resin for forming a three-dimensional structure.

  There is no limitation in particular in the use of the photomask manufactured by applying this invention.

  For example, it is suitable for a photomask for forming a contact hole as a photomask for manufacturing a display device. In particular, it can be used to form a so-called isolated hole pattern. Furthermore, structures such as photo spacers of color filters may be formed.

  It may be a so-called binary mask, or it may be a multi-tone photomask for forming a three-dimensional resist pattern having a plurality of remaining film amounts on a transfer target. Alternatively, it may be a phase shift mask that can improve contrast and the like by using a phase shift film.

  In addition, the present invention includes a photomask obtained by the above manufacturing method.

  The transfer pattern of the photomask includes a plurality of rectangular hole patterns, and when the dimension of the long side of the rectangle is X-CD, the plurality of hole patterns have mutually different X-CDs and different areas. It has the same shape. When the dimension of the short side is Y-CD, X-CD and Y-CD are preferably 3 μm or less.

  Alternatively, when the transfer pattern of the photomask includes a plurality of rectangular dot patterns, and the dimension of the long side of the rectangle is X-CD, the plurality of dot patterns have mutually different X-CDs, It has a shape with the same area. When the dimension of the short side is Y-CD, it is preferable that X-CD and Y-CD be less than 3 μm.

  Alternatively, the transfer pattern further has a square hole / dot pattern having the same area as the rectangular hole / dot pattern.

  Here, a pattern having a plurality of areas has the same CD (X-CD and Y-CD) in design pattern data (that is, pattern data before correction) based on the design of the device to be obtained. It can be a pattern and therefore a pattern to perform the same function in the final product.

  By applying the drawing method according to the present invention and the photomask manufacturing method using the same, the CD error amount can be suppressed to the allowable range or less over the entire in-plane area of the transferred object, and yield and production efficiency can be achieved. To contribute.

  The application of the photomask to which the present invention is applied is not particularly limited. It can apply suitably, when manufacturing various layers of these display devices using a photo mask for display device manufacture containing liquid crystal and organic EL.

Also, the photomask may be a so-called binary mask, or may be one having a functional film pattern having a predetermined transmittance (multi-gradation photomask, phase shift photomask, etc.).

Claims (16)

A pattern drawing method for forming a photomask provided with a transfer pattern including a hole / dot pattern by drawing on a photomask substrate based on predetermined design pattern data,
The design pattern data is corrected to obtain correction pattern data according to the correction value obtained in advance so that the CD of the hole / dot pattern obtained on the transfer target by exposing the photomask becomes a target value. A correction process,
Applying the correction pattern data, and performing drawing using a drawing apparatus;
The drawing apparatus is based on a driving method in which the CD control accuracy is different in an X direction and a Y direction perpendicular to the X direction in a plane parallel to the photomask substrate surface.
In the correction step, correction pattern data is obtained by performing correction on the design pattern data to change the CD in the direction with high CD control accuracy in the X direction and the Y direction with respect to the CD of the hole / dot pattern. A pattern drawing method characterized in that. In the correction step, a target area of the hole / dot pattern of the transfer pattern is determined such that the CD of the hole / dot pattern obtained on the transfer target is equal to a target value.
Based on the target area of the hole / dot pattern of the transfer pattern, the CD in the X direction and the Y direction of the hole / dot pattern is changed with respect to the CD of the hole / dot pattern with respect to the design pattern data. The pattern drawing method according to claim 1, wherein correction pattern data is obtained by performing correction. A pattern drawing method for forming a photomask provided with a transfer pattern including a hole / dot pattern by drawing on a photomask substrate based on predetermined design pattern data,
The design pattern data is corrected according to the correction value obtained in advance so that the area of the hole / dot pattern obtained on the transfer target by exposing the photomask becomes equal to the target value. The correction process to be obtained,
Applying the correction pattern data, and performing drawing using a drawing apparatus;
The drawing apparatus is based on a driving method in which the CD control accuracy is different in an X direction and a Y direction perpendicular to the X direction in a plane parallel to the photomask substrate surface.
In the correction step, correction pattern data is obtained by performing correction on the design pattern data to change the CD in the direction with high CD control accuracy in the X direction and the Y direction with respect to the CD of the hole / dot pattern. A pattern drawing method characterized in that. In the correction step, a target area of the hole / dot pattern on the transfer target is obtained.
The target area of the hole / dot pattern of the transfer pattern is determined based on the target area of the hole / dot pattern on the transfer target body,
Based on the target area of the hole / dot pattern of the transfer pattern, the CD in the X direction and the Y direction of the hole / dot pattern is changed with respect to the CD of the hole / dot pattern with respect to the design pattern data. 4. The pattern drawing method according to claim 3, wherein correction pattern data is obtained by performing correction.   The pattern drawing method according to claim 1, wherein the drawing apparatus is a laser drawing apparatus that performs drawing using a laser beam.   The X-CD and Y-CD of the hole / dot pattern in the transfer pattern are less than the resolution limit dimension of the exposure device that exposes the photomask. Pattern drawing method described.   The pattern drawing method according to any one of claims 1 to 5, wherein X-CD and Y-CD of the hole / dot pattern in the transfer pattern are less than 3 μm.   In the drawing apparatus, after the laser beam performs a delivery operation with a constant feed width in the X direction, an irradiation operation with a given width in the Y direction is performed, and these operations are alternately repeated to draw on the photomask substrate. The pattern drawing method according to any one of claims 1 to 7, characterized in that   In the correction process, a CD correction value obtained so that the area of the hole / dot pattern and the area of the hole / dot pattern on the photomask substrate included in the design pattern data are equal to that of the design pattern data The pattern drawing method according to any one of claims 1 to 8, wherein the correction pattern data is obtained by substituting CD. Prior to the correcting step, obtaining a preliminary mask on which a pattern is drawn using the drawing device;
The pattern drawing method according to any one of claims 1 to 9, further comprising a correction value grasping step of grasping the correction value by X-CD and Y-CD of the preliminary mask.   The manufacturing method of a photomask including the drawing method in any one of Claims 1-10. A photomask provided with a transfer pattern including a plurality of hole / dot patterns, wherein
The plurality of hole / dot patterns in the transfer pattern have X-CD and Y-CD less than 3 μm,
A photomask, wherein the plurality of hole / dot patterns in the transfer pattern include hole / dot patterns having X-CDs different from one another and square shapes having equal areas. Providing a photomask according to claim 12;
A method for producing a display device, comprising transferring the transfer pattern onto a transfer target using an exposure apparatus having an NA of an optical system of 0.08 to 0.20. A method of manufacturing a display device, comprising transferring a transfer pattern of a photomask onto a transfer target by exposing a photomask formed based on predetermined design pattern data.
The design pattern data is corrected to obtain correction pattern data according to the correction value obtained in advance so that the CD of the hole / dot pattern obtained on the transfer target by exposing the photomask becomes a target value. A correction process,
A drawing process of applying the correction pattern data and drawing on a photomask substrate using a drawing apparatus;
Developing and etching the photomask substrate to form a photomask provided with the transfer pattern;
Exposing the photomask with an exposure device to form a hole / dot pattern on a transfer target,
The hole / dot pattern X-CD and Y-CD in the transfer pattern is less than 3 μm,
In the correction step, correction is performed by changing the CD of the hole / dot pattern in the design pattern data in the direction in which the CD control accuracy of the drawing device is high among the X direction and Y direction. A method of manufacturing a display device, comprising obtaining pattern data. Prior to the correcting step, obtaining a preliminary mask provided with a preliminary transfer pattern drawn using the drawing apparatus;
15. The method according to claim 14, further comprising: a correction value grasping step of grasping the correction value by the CD of the hole / dot pattern formed on the transfer object by exposing by the exposure device using the preliminary mask. The manufacturing method of the display apparatus as described. A method of manufacturing a display device, comprising transferring a transfer pattern of a photomask onto a transfer target by exposing a photomask formed based on predetermined design pattern data.
The design pattern data is corrected according to the correction value obtained in advance so that the area of the hole / dot pattern obtained on the transfer target by exposing the photomask becomes equal to the target value. The correction process to be obtained,
A drawing process of applying the correction pattern data and drawing on a photomask substrate using a drawing apparatus;
Developing and etching the photomask substrate to form a photomask provided with the transfer pattern;
Exposing the photomask with an exposure device to form a hole / dot pattern on a transfer target,
The hole / dot pattern X-CD and Y-CD in the transfer pattern is less than 3 μm,
In the correction step, correction is performed by changing the CD of the hole / dot pattern in the design pattern data in the direction in which the CD control accuracy of the drawing device is high among the X direction and Y direction. A method of manufacturing a display device, comprising obtaining pattern data.