TWI409579B - Method of manufacturing a photomask lithography apparatus, method of inspecting a photomask and apparatus for inspecting a photomask - Google Patents

Abstract

PURPOSE: A method of manufacturing photomask, a lithography apparatus, a method and an apparatus for inspecting a photomask are provided to transfer a preset transfer pattern on a photoresist film of a photomask blank by writing and developing the transfer pattern on the photoresist film of a photomask blank. CONSTITUTION: A photomask blank(13) is fixed on a stage(10). A thin film(14) including a light-shielding layer is formed in one side of a photomask blank. A writing unit(11) writes the preset transfer pattern on the photomask blank. A height measurement unit(12) is arranged with the preset distance from the surface of the photomask blank. A writing data production unit(15) produces the writing data by correcting the design writing data.

Description

Photomask manufacturing method, drawing device, photomask inspection method, and photomask inspection device

The present invention relates to a method of manufacturing a photomask used in the manufacture of an LSI or a liquid crystal display device (hereinafter referred to as LCD), a drawing device, a method of inspecting a photomask, and an inspection device for a photomask.

Thin Film Transistor Liquid Crystal Display (hereinafter referred to as TFT-LCD), compared with CRT (Cathode Ray Tube), is currently commercialized and large-sized due to its advantages of thinness and low power consumption. Rapid progress. A TFT-LCD having a TFT substrate having a structure in which pixels are arranged in a matrix in a matrix, and a color filter in which pixel patterns of red, green, and blue are arranged in correspondence with each pixel, and the liquid crystal phase is overlapped structure.

In the manufacture of a TFT-LCD, as in the manufacture of an LSI, a lithography step using a projection exposure technique is necessary. The reticle used as a mask when performing the projection exposure is formed on a transparent substrate, and is patterned to form an exposure transfer pattern including a light transmitting portion and a light shielding portion (including a semi-transparent The situation of the Ministry). The transfer pattern has to be correctly positioned to a specific position with respect to a specific coordinate of the design. The correctness of the positional relationship is proportional to the finer and higher resolution of the pattern, and is required to have a higher degree of correctness.

The transfer pattern is usually formed on a blank mask having a light-shielding film and/or a semi-transmissive film (hereinafter referred to as a film) on the surface of the light-transmitting substrate to form a resist film, and becomes a blank mask with a resist film. After the transfer film is patterned by an energy beam such as a laser or an electron beam, the resist pattern is formed by etching using the developed resist pattern. In the drawing step, the blank mask with the resist film is held on the pedestal, and the pattern to be drawn is stored as a design drawing data on the computer, and the position of the light irradiation and/or the position of the pedestal is controlled based on the design drawing data. Depiction.

Here, it is considered that it is necessary to expose the transfer pattern formed by the drawing, the development by the resist, the etching of the film, and the transfer pattern actually formed by the mask, as specified by the user of the mask. The transfer pattern is correct and consistent. Further, the pattern to be transferred onto the object to be transferred (device such as a liquid crystal panel) using the mask must satisfy the specifications required by the user of the mask. When pattern transfer is performed using a photomask that does not satisfy this condition, a large number of defective devices are manufactured.

For example, Japanese Laid-Open Patent Publication No. Hei 7-273160 (Patent Document 1) discloses a method of evaluating a mask pattern, and investigates a transfer pattern actually formed for a mask to be manufactured, and a transfer indicated by design drawing data. Whether the printed pattern is consistent with a certain accuracy.

Japanese Patent Publication No. 2007-512551 (Patent Document 2) discloses a surface writing pattern used in an exposure apparatus, in which a blank mask having a thickness T is disposed on a drawing device (drawing device). On the pedestal, the surface is divided into a plurality of measurement points, the slope of the surface in each measurement point is measured, the two-dimensional local offset d in the XY plane of each point is calculated, and the pattern is corrected using the two-dimensional local offset d.

According to Patent Document 1, although the pattern can be evaluated, the transfer pattern formed on the photomask cannot be transferred to the object to be transferred by exposure, and the coordinate accuracy cannot be improved.

Further, in Patent Document 2, the exposure system or the like is a method of writing a pattern to an object regardless of all physical deformations generated when the pattern is written, but the difference between the drawing step and the exposure step is not considered and distinguished. Since the physical deformation of the object in the step differs depending on the cause of the physical deformation, it is difficult to form a photomask having a pattern having sufficient precision with respect to the design drawing data by the method of Patent Document 2.

Here, the "design drawing data" is a pattern material that reflects the design of the pattern shape of the device to be obtained.

In order to provide a method of manufacturing a photomask, an inspection method, and an apparatus, the present invention can produce a pattern of an electronic device such as a TFT with higher precision in the manufacture of an electronic device such as an LSI or an LCD.

Usually, the blank photomask film surface placed in the state of the drawing machine is a non-ideal planar shape, which is deformed by various kinds. Furthermore, the deformation factor when the blank mask is placed on the drawing machine is different from the deformation factor when the mask is exposed. That is, the film surface which is deformed from the plane which is ideal as described above is drawn, and when the mask pattern surface formed is changed to a shape different from that at the time of drawing, a desired pattern determined by the design drawing material occurs. , can not be properly transferred to the transfer body.

The inventors of the present invention analyzed in detail the causes of the deformation of the surface shape of the blank mask when placed on the pedestal of the drawing machine, and clarified the causes of the deformation and the residual deformation of the residual mask when the mask was used in the exposure apparatus. Further, it is considered that the coordinates of the coordinates caused by the disappearance of the exposure are corrected, and the design drawing data is corrected to obtain the drawing data.

When the pattern is drawn by the drawing machine on the blank mask with the photoresist, the blank mask is placed on the pedestal of the drawing machine with the film surface facing up. At this time, the cause of the surface shape of the blank mask film surface being deformed from the ideal flat surface is considered to be: (1) insufficient flatness of the pedestal, and (2) scratching of the substrate due to foreign matter inclusion on the pedestal (3) Concavities and convexities on the surface of the substrate of the blank mask, and (4) four factors due to deformation of the back surface of the substrate. That is, the deformation of the surface shape of the blank mask in this state is the result of the accumulation of the above four factors. Then, the blank mask of this state is depicted.

On the other hand, when the reticle is used in the exposure apparatus, it is fixed by supporting only the end portion with the film facing downward. The transferred body on which the resist film is formed is placed under the reticle, and the exposure light is irradiated from above the reticle. In this state, among the four deformation factors, (1) the insufficient flatness of the pedestal, and (2) the deflection of the substrate due to the inclusion of foreign matter on the pedestal disappears. Further, (4) the unevenness on the back surface of the substrate remains in this state, but the surface shape of the back surface on which the pattern is not formed does not affect the transfer of the surface (pattern forming surface). On the other hand, (3) the unevenness of the surface of the substrate of the blank mask is also a residual deformation factor when the photomask is used in the exposure apparatus. Further, when the photomask is placed on the exposure machine, the end portion is deflected by the weight of the mask when the end portion is supported, and the compensation method mounted on each exposure machine can be used for the deflection component, and it is generally believed that the transfer belt is not applied. Bad influence.

According to the above, in the above-described example, the surface shape of the upper surface of the blank mask in the state where the film is placed on the pedestal of the drawing machine is measured, and in the surface shape, the above (1), (2), and (4) become It is necessary to correct the design and depiction data as part of the change from the ideal plane of the surface shape, and on the other hand, (3) becomes the part of the surface shape change. If it is not reflected in the above correction, it will be more correct. Photomask for transfer performance of coordinate design data.

Further, when the surface shape is measured, it is measured on the resist film which is peeled off when the mask is formed, but the deformation is affected by the accuracy of the coordinates based on the deformation of (1) to (4). Since the film thickness of the resist film is extremely small (usually about 800 to 1000 nm), the variation thereof is smaller, and therefore no obstacle is caused even when measured from the surface of the resist film.

That is, the method for manufacturing a photomask according to the present invention includes the steps of drawing, wherein the drawing step is performed on a blank mask including a transparent substrate, a thin film on the transparent substrate, and a photoresist film on the thin film, and is specified by a drawing machine. Depicting the data irradiation energy beam to depict a specific transfer pattern; and calculating the shape of the film surface side of the blank mask in the drawing step and the blank light when exposing the mask The shape change portion of the shape of the film surface side of the cover is corrected based on the calculated shape change portion, and the design drawing data for the specific transfer pattern is corrected to obtain the specific drawing material.

Furthermore, the shape change portion described herein may not include the deflection component due to the self-weight of the mask when the photomask is placed on the exposure machine. The reason for this is that the compensation for the coordinate deviation of the pattern due to the deflection is performed by the method of mounting on the exposure device, and therefore the drawing data can be ignored.

Furthermore, the method for manufacturing a photomask according to the present invention includes the steps of drawing, wherein the drawing step is performed on a blank mask including a transparent substrate, a thin film on the transparent substrate, and a photoresist film on the thin film, and is drawn by a drawing machine. The specific drawing data is irradiated with the energy beam to depict a specific transfer pattern; and, by using: the blank mask is placed on the pedestal of the drawing machine with the surface of the film as the upper side, and the measurement is performed. The blank surface height distribution data obtained by the height distribution of the upper surface of the blank mask and the film surface shape data of the blank mask obtained in advance are corrected for designing and drawing the specific transfer pattern. The specific depiction data described above is obtained.

In addition, the manufacturing method of the photomask of the present invention comprises: preparing a blank mask including a transparent substrate, a film on the transparent substrate, and a photoresist film on the film; and the blank mask has the surface of the film a step of loading the upper side on the pedestal; obtaining the blank surface height distribution data by measuring the height distribution of the upper surface of the blank mask on the pedestal; and using the film surface of the blank mask previously obtained Shape data and the blank surface height distribution data, correcting the design drawing data for the specific transfer pattern, and obtaining a specific drawing data step; and by irradiating the energy to the foregoing photoresist film according to the specific drawing data The beam, while depicting the steps of the aforementioned specific transfer pattern.

In the above method for manufacturing a photomask according to the present invention, the correction of the design drawing data preferably includes determining a difference between the blank surface height distribution data and the film surface shape data. For example, the step of subtracting the aforementioned film surface shape data from the blank surface height distribution data may be included. Further, in the method of manufacturing a photomask according to the present invention, in the correction of the design drawing data, a difference data obtained by obtaining a difference between the blank surface height distribution data and the film surface shape data may be used based on the blank light. The slope of the height direction of the blank mask in the plurality of positions on the surface of the cover and the thickness of the blank mask are converted by the coordinate values of the design drawing data. Alternatively, a difference data obtained by obtaining a difference between the blank surface height distribution data and the film surface shape data may be used, based on a slope of a height direction of the blank mask in a plurality of positions on the surface of the blank mask. The thickness of the blank mask is corrected by modifying the drawing coordinate system of the drawing machine. In other words, in the present invention, the "correction of the design drawing data" includes not only the case where the design drawing data itself is corrected, but also the case where the same effect is obtained by correcting the drawing coordinate system of the drawing machine at the time of drawing.

Further, the step of etching the film may be further included as a mask by using a resist pattern obtained by drawing the transferred transfer pattern as a mask.

Further, the drawing device of the present invention is characterized in that a specific transfer pattern is drawn on a blank mask on which a photoresist film is formed on the surface, and includes a height measuring mechanism that is disposed by measuring the photoresist film facing upward. a height distribution of the surface of the blank mask on the pedestal to obtain a blank surface height distribution data; and an operation mechanism for using the film surface shape data of the blank mask previously obtained and the blank surface height distribution data, Correcting the design drawing data for the specific transfer pattern described above to obtain a specific drawing material; and drawing a mechanism for irradiating the energy beam to the photoresist film in accordance with the specific drawing data. Here, the correction of the design drawing data, as described above, includes the case of correcting the drawing coordinate system when drawing the design drawing data in addition to the case of correcting the design drawing data itself. It is more preferable to have a drawing device that corrects the mechanism (computing mechanism) that draws the coordinate system.

In addition, the method for inspecting a photomask of the present invention is to inspect a photomask including a transfer pattern of a thin film on a transparent substrate, and includes: placing the photomask on the upper side of the surface having the transfer pattern a step of obtaining a mask surface height distribution data by measuring a height distribution of a surface of the upper surface of the reticle on the pedestal; and measuring a shape of the transfer pattern of the reticle on the pedestal to obtain a step of patterning the length data; and modifying the pattern length measurement data or the design drawing data for the transfer pattern by using the film surface shape data of the mask obtained in advance and the mask surface height distribution data.

For example, the method may be characterized in that the pattern length data of the mask and the mask surface height distribution data obtained in advance are used to correct the pattern length measurement data, and the corrected pattern length measurement data and the design drawing data are compared. Alternatively, the method of correcting the design drawing data and comparing the corrected design drawing data and the pattern length measuring data by using the mask surface shape data of the mask obtained in advance and the mask surface height distribution data may be used. As the film surface shape data used at this time, the film surface shape data of the mask portion can be approximated.

Furthermore, the inspection apparatus for the photomask of the present invention is for inspecting a photomask including a transfer pattern formed by a thin film on a transparent substrate, and may include: a height measuring mechanism that measures the transfer pattern toward a height distribution of the surface of the reticle disposed on the pedestal to obtain a height distribution of the mask surface; and a length measuring mechanism for measuring a shape of the transfer pattern of the reticle on the pedestal to obtain a pattern measurement And a computing unit that corrects the pattern length measuring data or the design drawing data for the transfer pattern by using the film surface shape data of the mask obtained in advance and the mask surface height distribution data .

For example, the inspection apparatus including a reticle includes: an arithmetic unit that corrects the pattern length measurement data by using the mask surface shape data of the reticle obtained in advance and the mask surface height distribution data; and comparing The organization compares the corrected pattern length measurement data with the aforementioned design depiction data.

Furthermore, an inspection apparatus including a reticle includes: an arithmetic unit that corrects the design drawing data using the previously obtained film surface shape data and the mask surface height distribution data; and a comparison mechanism It compares the corrected design drawing data with the aforementioned pattern length measuring data.

In the method for manufacturing a photomask according to the present invention, the surface shape of the film surface side of the blank mask in a state of being placed on the pedestal of the drawing machine is measured, and the blank mask is formed from the ideal plane of the surface shape. In the state in which the mask is formed and placed in the exposure apparatus, the design drawing data is corrected in the portion where the surface shape changes. Specifically, in the case of the deformation of the ideal plane of the film surface shape at the time of drawing, the portion remaining in the exposure (the unevenness of the film surface) and the portion which disappears during the exposure (the deflection of the substrate due to the foreign matter, etc.), It is equivalent to the coordinate deviation of the disappearing part at the time of exposure, and the design drawing data is corrected to obtain a specific drawing data. According to this, when the mask is used, the transfer pattern transferred onto the transfer target body accurately reflects the design drawing material of the desired device pattern.

Further, in the mask inspection step, the length measurement data obtained in the state of being placed on the pedestal of the inspection machine is equivalent to the deformation of the substrate due to the deflection of the substrate caused by the foreign matter. Coordinate deviation, correction of length measurement data or design depiction data, comparison with design depiction data, evaluation of the mask. According to this, the quality of the pattern formed on the mask can be correctly evaluated.

Hereinafter, embodiments of the present invention will be described using the drawings, the examples, and the like. The drawings, the examples, and the like are intended to illustrate the invention and are not intended to limit the scope of the invention. Other embodiments that are within the scope of the spirit of the invention are also within the scope of the invention.

Fig. 1 is a conceptual diagram of a drawing device used in a method of manufacturing a mask according to an embodiment of the present invention. The drawing device includes at least a pedestal 10, a drawing unit 11, a height measuring unit 12, and a drawing data creating unit 15 (computing means). A blank mask 13 is fixed to the pedestal 10. The blank mask forms a film 14 including at least a light shielding film on one side, and the film 14 is formed to face upward. The drawing means 11, for example, irradiates a laser, and in the drawing step, a specific transfer pattern is drawn on the blank mask 13 with the photoresist film attached to the pedestal 10.

The height measuring mechanism 12 is disposed at a predetermined distance from the surface of the blank mask 13 by, for example, an air cushion. The height measuring means 12 can measure the change in the height (Z direction) of the surface of the blank mask 13 in response to the change in the height of the surface shape of the blank mask 13 and the height.

Further, as a method of measuring the surface height, in addition to the above, a method for measuring the air flow rate for maintaining the same member as the height measuring mechanism 12 at a predetermined position or a capacitance between the gaps may be used. Laser pulse counting, optical focusing, etc.

The drawing data creating unit 15 corresponds to the shape of the film surface side in the drawing step of the blank mask 13 and the shape change of the shape of the film surface side during exposure when the mask is produced by the blank mask 13, and the specific drawing should be corrected. The design of the shape of the transfer pattern is drawn to depict the data. For example, the drawing creation mechanism 15 is based on the data indicating the change in the surface shape height of the blank mask 13 from the film surface shape data height measuring mechanism 12 of the blank mask 13, and the film surface shape data of the blank mask 13 obtained in advance. The design drawing data is corrected, and the drawing data drawn by the drawing mechanism 11 is created.

Furthermore, as described above, the correction of the drawing data can be performed not only when the corrected drawing data is created, but also by the drawing coordinate system of the drawing machine.

Both the drawing mechanism 11 and the height measuring mechanism 12 are movable in a plane parallel to the pedestal by holding a mechanism that moves on the pedestal 10 in the x direction and the y direction (not shown). Instead of this, the fixed drawing mechanism 11 and the height measuring mechanism 12 may be provided, and the pedestal 10 may be moved in parallel in the x direction and the y direction, or the drawing unit or the like may be provided in the x direction and the other side in the pedestal. A mechanism that moves in the y direction and moves the drawing mechanism or the like to a desired position on the pedestal by relative movement.

2 is an enlarged cross-sectional view of the blank reticle 13 on the pedestal 10 of the device. For example, a section perpendicular to the y-axis (a plane parallel to the x-axis). The film 14 is omitted. The shape of the surface 20 of the blank mask 13 disposed on the pedestal 10 is deformed from the ideal plane due to the plural of the foregoing.

Hereinafter, a method of measuring the deformation of the surface shape of the blank mask 13 on the pedestal 10 will be described with reference to FIG. 2 by the height measuring mechanism 12. The surface of the blank mask 13 in the case of an ideal plane without deformation is the reference surface 21. In the specific measurement point 22, the height is measured by the height measuring means 12, and the measurement is repeated at a specific interval Pitch. The difference between the height measured by the height measuring mechanism 12 and the reference surface 21 is used as the blank surface height distribution data.

When the blank surface height distribution data and the measurement point of 0 (that is, the measurement point whose height coincides with the reference surface 21) are adjacent to each other, the blank surface height distribution data is H, and the surface of the blank mask 13 is distinguished by the height difference. The angle Φ between the 20 and the reference surface 21 is sufficiently small, and the following expression is expressed:

sinΦ=H/Pitch‧‧‧ (Formula 1)

Moreover, in the foregoing, the H/Pitch may also consider the slope of the height direction of the blank mask surface.

Furthermore, if the value of Φ is sufficiently small, it can also be approximated as:

Φ=H/Pitch‧‧‧ (Formula 1')

(Formula 1) is used in the following description.

In the foregoing case, the deviation d of the x-axis direction of the measurement point due to the height difference can be generally obtained by the following formula:

d=sinΦxt/2=Hx(t/2Pitch)‧‧‧ (Formula 2)

Furthermore, in the above, if Φ is sufficiently small, it can also be approximated as:

d=Φxt/2=Hx(t/2Pitch)‧‧‧ (Formula 2').

Furthermore, here t is the thickness of the blank mask.

The above-described measurement is performed at a predetermined interval Pitch in the x direction and the y direction of the blank mask 13, whereby the deviation of the measurement points due to the change in the surface shape of each measurement point can be measured.

As a result of the above measurement, as described above, it is considered that (1) the pedestal 10 has insufficient flatness, (2) the deflection of the substrate due to the foreign matter on the pedestal 10, and (3) the blank mask 13 The unevenness of the surface of the substrate, (4) the shape of the surface of the four blank masks of the blank back surface of the blank mask 13 from the ideal plane is changed due to the height.

On the other hand, an example of use of an exposure apparatus for a photomask produced by transferring a specific transfer pattern to a blank mask is shown in FIG. Figure 3 is a conceptual diagram of an exposure apparatus. The photomask 30 supports both ends with a support body 31, and the film surface 32 is disposed downward. The transfer target 33 is disposed under the mask 30. The exposure light from the light source 34 is irradiated from the reticle 30, and is irradiated onto the object to be transferred via the reticle 30.

Furthermore, the photomask actually supported in the exposure apparatus is deflected by its own weight. However, the compensation mechanism for the deviation of the pattern coordinates of the deflection is mounted on the exposure device.

In this state, as described above, in the four deformation factors, only the unevenness of the substrate surface (film surface 32) of the blank mask 13 remains (3), (2), and (4) disappear, so In this case, the shape of the film surface (pattern forming surface) during the drawing and the exposure is changed, and the total of the above (1), (2), and (4) is caused, and the deviation from the pattern coordinates is also caused. Respond to the change. Therefore, when the transfer pattern is drawn, the deviation of the above four deformation factors is caused by the deviation of (3), and only the deviation portions due to (1), (2), and (4) are necessary, and it is necessary to correct the transfer pattern. Design and depicting materials.

In the present invention, it is effective to obtain in advance information on the surface unevenness of the substrate of the blank mask (the flatness data of the blank mask film surface). This data can be obtained by vertically erecting a blank mask and measuring the surface shape of the blank mask in a state where the deflection due to the weight of the substrate is removed. The measurement can be carried out by a general optical measurement method. The height variation (the difference between the height measured value and the reference surface) of the measurement point obtained by the measurement was taken as the film surface shape data. If the film surface shape data is H ₁ , the height variation due to (1), (2), and (4) is HH ₁ , and according to formula (2), it is caused by (1), (2), and (4). The deviation can be obtained by the following formula.

d ₁ =(HH ₁ )×t/2Pitch‧‧‧ (Formula 3)

In the drawing data creation unit 15, the design drawing data of the transfer pattern is corrected using the above d _{1 to} create a drawing material. The drawing means 11 is used to draw a transfer pattern on the photoresist film on the blank mask 13 based on the drawing material, and processing such as development is performed. Therefore, a specific transfer pattern can be transferred to the photoresist film on the blank mask 13. The film 14 is etched by using the photoresist film as a mask, and thus a photomask can be obtained.

(Example)

Hereinafter, embodiments of the invention will be described.

Prepare a glass substrate having a thickness of 13 mm and a size of 1220 mm × 1400 mm, on which the substrate is 1250 A light-shielding film containing Cr as a main component was formed in the film thickness to form a blank mask.

In the glass substrate, the surface shape of the light-shielding film formation surface side is measured at a predetermined interval by a normal optical measurement in a vertical erect state, and the film surface shape data H ₁ of each measurement point is obtained. The light-shielding film is formed by sputtering, and a CrO having anti-reflection function is formed on the surface portion of the Cr film.

Further, the surface shape of the film surface side of the blank mask may be measured as described above.

Next, a blank mask of a positive-type resist film having a thickness of 800 nm was applied onto the light-shielding film by a capillary coater, and the drawing device shown in FIG. 1 was placed such that the light-shielding film was formed to face upward. The height measuring means 12 of the drawing device measures the height variation at a predetermined interval, and obtains the blank surface height distribution data H of each measurement point. The measurement points were carried out at the same points as the surface shape measurement performed vertically.

The height variation difference HH _{1 of} each measurement point is obtained, and the distribution of the distribution is shown in FIG. 4 in a three-dimensional graph.

In Fig. 4, the lateral direction of the blank mask surface is in the x-axis direction, the longitudinal direction is the y-axis direction, and the depth is the thickness direction of the blank mask. In Fig. 4, the region M1 is a region in which the height variation HH ₁ is 5 μm to 10 μm. Similarly, the region M2 is in a region of 0 μm to 5 μm, the region M3 is in a region of -5 μm to 0 μm, the region M4 is in a region of -10 μm to -5 μm, and the region M5 is in a region of from -15 μm to 10 μm. As can be seen from Fig. 4, the difference in height variation between the centers of the blank mask is small, and the change becomes steeper toward both ends in the y-axis direction.

Next, in the blank mask, design drawing materials in which patterns are arranged at specific intervals are used, and the drawing is performed without correction. The deviation between the coordinate measurement result of the pattern and the design drawing data is shown in Fig. 5. In Fig. 5, the lateral direction is the x-axis direction and the longitudinal direction is the y-axis direction. In addition, the white circle is the actual measured data of the depiction, and the black circle is the design depiction data. It can be seen from Fig. 5 that, near the center of the blank mask, the deviation between the measured data and the design drawing data is small, so the black circle portion is hardly left, but the two ends of the y-axis direction are relatively large, so the black circle portion is relatively large. Ground residue.

As described above, comparing FIG. 4 with FIG. 5, it is confirmed that the difference HH ₁ of the height variation obtained in FIG. 4 is related to the deviation of the self-designed drawing data of the actual measured data. Accordingly, when the transfer pattern is drawn, the deviation of the four deformation factors is caused by the deviation of the unevenness of the substrate surface of the blank mask 13 remaining in the exposure apparatus, and only the cause is caused by (1) The flatness of the pedestal 10, (2) the deflection of the substrate on which the foreign matter is interposed on the pedestal 10, and (4) the deviation of the unevenness of the back surface of the substrate of the blank mask 13, the design of the modified transfer pattern The data was created to depict the data, and it was confirmed that the deviation between the transfer pattern actually formed on the photomask and the design drawing data was reduced.

Furthermore, the method of manufacturing the photomask described above can also be used in the inspection method of the photomask. In other words, in the pedestal 10 of the inspection machine (indicated by the symbol of the drawing device shown in FIG. 1), the mask is placed on the film surface (pattern forming surface) upward, and the height measuring mechanism 12 obtains light in the same manner as described above. The mask height distribution data of the cover. The mask surface height distribution data, like the blank surface height distribution data, includes deformation of the surface shape due to four deformation factors from the ideal plane. Next, the length of the pattern shape of the photomask is measured to obtain pattern length measurement data. The pattern length measurement data includes variations due to deformation of the surface shape of the four deformation factors.

Furthermore, the surface shape of the film surface of the reticle was measured in a state in which the reticle was vertically erected, and the film surface unevenness of the reticle was obtained as the film surface shape data. The measurement can be carried out by a general optical measurement method. The film surface shape data is the same as described above, and includes (3) deformation of the surface shape caused by the unevenness of the surface of the mask. Furthermore, the film surface shape data is obtained at the stage before the manufacture of the mask (the stage of the blank mask or the substrate), and the film surface shape data can also be used.

By subtracting the value of the film surface shape data from the mask surface height distribution data, the pattern length measurement data is corrected using (Formula 3), and the pattern shape when the mask is actually used in the exposure apparatus can be calculated. By comparing the modified pattern length measurement data with the design drawing data of the pattern, the actual deviation of the mask can be estimated, and the mask can be evaluated. For example, the mask can be regarded as a good product only if the deviation is within a certain range.

Alternatively, the design data of the pattern can be corrected by using (Formula 3) by subtracting the value of the film surface shape data from the mask surface height distribution data. The reticle can be evaluated by comparing the corrected design depiction data with the aforementioned pattern length measurement data.

Furthermore, the present invention is not limited to the above embodiment, and can be implemented as appropriate. For example, in the above-described embodiment, the laser beam is used as the drawing means of the drawing device. However, the present invention is not limited thereto, and may be an energy beam such as an electron beam.

Further, although a light-shielding film is formed as a film as a mask, a multi-step mask having a semi-transmissive film may be used in addition to the light-shielding film. In this case, the photoresist film formation, the drawing step, and the etching step are repeated only in accordance with the number of necessary transfer patterns.

In general, in the reticle manufacturing process in which the photolithography step is required to be performed twice or more, the alignment deviation is often a big problem due to the secondary patterning. However, if the correction of the drawing data of the present invention is used for each of the plurality of drawing steps, the alignment of the patterns when the mask is exposed and the pattern is transferred to the object to be transferred can be performed very accurately, so that it is suitable. . That is, when a blank mask having a plurality of light-shielding films formed on a substrate is subjected to plural drawing, resist development, and film etching to finally form a mask having a desired transfer pattern, the present invention can be applied to each drawing. Delineation method/drawing device.

At this time, in the first drawing and the second drawing, since the deformation of the blank film surface is different, the correction of the drawing data is also different. Then, as a result, one transfer pattern of the photomask formed by the second drawing is formed, and a desired pattern is correctly formed on the transfer target.

Furthermore, the inspection method/inspection device of the present invention can also be applied to each inspection step.

Further, the materials, dimensions, processing steps, and the like of the above embodiments can be implemented by various modifications.

10. . . Pedestal

11. . . Depiction agency

12. . . Height measuring mechanism

13. . . Blank mask

14. . . film

15. . . Descriptive data creation agency

20. . . Blank reticle surface

twenty one. . . Reference surface

twenty two. . . Measuring point

30. . . Mask

31. . . Support

32. . . Membrane surface

33. . . Transferred body

34. . . light source

M1~M5. . . region

1 is an external view showing a drawing device according to an embodiment of the present invention;

Figure 2 is a cross-sectional view showing a blank mask of an embodiment of the present invention;

Figure 3 is an external view showing an exposure apparatus using a photomask according to an embodiment of the present invention;

Figure 4 is a distribution diagram showing the height variation of the surface of the blank mask of the embodiment of the present invention;

Fig. 5 is a view showing the deviation between the measured data and the design drawing data of the embodiment of the present invention.

10. . . Pedestal

11. . . Depiction agency

12. . . Height measuring mechanism

13. . . Blank mask

14. . . film

15. . . Descriptive data creation agency

Claims (15)

A method of manufacturing a photomask, comprising: a drawing step of blank film on a transparent substrate, a thin film on the transparent substrate, and a photoresist film on the thin film, and a specific drawing using a drawing machine The data is irradiated with an energy beam to depict a specific transfer pattern; and by calculating the shape of the film surface side of the blank mask in the drawing step and the film of the blank mask when the mask is exposed The shape change portion of the shape of the face side is corrected based on the shape change portion, and the design drawing data for the specific transfer pattern described above is corrected to obtain the specific drawing material described above. A method of manufacturing a photomask, comprising the step of drawing a blank mask comprising a transparent substrate, a thin film on the transparent substrate, and a photoresist film on the thin film, and using a drawing machine to irradiate energy according to a specific drawing data a beam is drawn to depict a specific transfer pattern; and the upper side of the blank mask is measured by using the blank mask on the pedestal of the drawing machine with the surface of the film as the upper side. The blank surface height distribution data obtained by the height distribution and the film surface shape data of the blank mask previously obtained are corrected, and the design drawing data for the specific transfer pattern described above is corrected to obtain the specific drawing material described above. A method of manufacturing a photomask, comprising: preparing a blank mask comprising a transparent substrate, a film on the transparent substrate, and a photoresist film on the film; and the blank mask has an upper surface of the film a step of loading the pedestal; obtaining a blank surface height distribution data by measuring a height distribution of the upper surface of the blank reticle on the pedestal; and using the film shape data of the blank reticle obtained in advance And the blank surface height distribution data, modifying a design drawing data for a specific transfer pattern to obtain a specific drawing data; and irradiating the energy beam to the foregoing photoresist film according to the specific drawing data, The step of depicting the aforementioned specific transfer pattern is described. The method of manufacturing the reticle of claim 2 or 3, wherein the correction of the design drawing data comprises determining a difference between the blank surface height distribution data and the film surface shape data. The method of manufacturing the reticle of claim 2 or 3, wherein the correction of the design drawing data is performed by using a difference data obtained by obtaining a difference between the blank surface height distribution data and the film surface shape data, based on the blank light The slope of the height direction of the blank mask in the plurality of positions on the surface of the cover is performed with the thickness of the blank mask. The method of manufacturing the reticle of claim 2 or 3, further comprising: forming a photoresist pattern formed by using the specific transfer pattern drawn by the drawing material obtained by modifying the design drawing data as a mask, and The step of etching the aforementioned film. A method of manufacturing a reticle according to claim 6, comprising forming a plurality of said thin films on said transparent substrate, and said each of said plurality of films is formed by said specific drawing using said specific drawing material. The pattern formed by the photoresist pattern is etched as a mask. A drawing device for drawing a specific transfer pattern on a blank mask having a photoresist film formed on the surface thereof, and comprising: a height measuring mechanism configured to measure the photoresist film upward on the pedestal The height distribution of the surface of the blank mask to obtain the blank surface height distribution data; and the calculation mechanism for correcting by using the film surface shape data of the blank mask previously obtained and the blank surface height distribution data And the drawing means for obtaining the specific drawing material in the designation of the specific transfer pattern; and the drawing means for irradiating the energy beam to the photoresist film according to the specific drawing data. A method for inspecting a photomask for inspecting a photomask including a transfer pattern of a film on a transparent substrate, and comprising: step of placing the photomask on the pedestal with the surface having the transfer pattern as an upper side And obtaining a mask surface height distribution data by measuring a height distribution of the upper surface of the reticle on the pedestal; determining a shape of the transfer pattern of the reticle on the pedestal to obtain a pattern length measurement And the step of modifying the pattern length measurement data or the design drawing data for the transfer pattern by using the mask surface shape data of the mask obtained in advance and the mask surface height distribution data. A method for inspecting a photomask for inspecting a photomask including a transfer pattern of a film on a transparent substrate, and comprising: step of placing the photomask on the pedestal with the surface having the transfer pattern as an upper side And obtaining a mask surface height distribution data by measuring a height distribution of the upper surface of the reticle on the pedestal; determining a shape of the transfer pattern of the reticle on the pedestal to obtain a pattern length measurement a step of data; a step of correcting the pattern length measurement data by using the mask surface shape data of the mask obtained in advance and the mask surface height distribution data; and comparing the corrected pattern length measurement data with the correction The design of the printed pattern depicts the steps of the data. A method for inspecting a photomask for inspecting a photomask including a transfer pattern of a film on a transparent substrate, and comprising: step of placing the photomask on the pedestal with the surface having the transfer pattern as an upper side And obtaining a mask surface height distribution data by measuring a height distribution of the upper surface of the reticle on the pedestal; determining a shape of the transfer pattern of the reticle on the pedestal to obtain a pattern length measurement a step of data; correcting a step of designing and drawing data for the transfer pattern by using a film surface shape data of the mask obtained in advance and the mask surface height distribution data; and comparing the corrected design drawing data with the correction The steps of the aforementioned pattern length measurement data. The method for inspecting a photomask according to any one of claims 9 to 11, wherein the film surface shape data of the blank mask previously obtained is used as the film surface shape data of the photomask. An inspection device for a photomask for inspecting a photomask including a transfer pattern of a film on a transparent substrate, and comprising: a height measuring mechanism disposed on the pedestal by measuring the transfer pattern upward a height distribution of the surface of the reticle to obtain a height distribution of the mask surface; a length measuring mechanism for measuring a shape of the transfer pattern on the pedestal to obtain a pattern length measuring data; and an arithmetic mechanism The pattern length data or the design drawing data for the transfer pattern is corrected using the mask surface shape data of the mask and the mask surface height distribution data obtained in advance. An inspection device for a photomask for inspecting a photomask including a transfer pattern of a film on a transparent substrate, and comprising: a height measuring mechanism disposed on the pedestal by measuring the transfer pattern upward a height distribution of the surface of the reticle to obtain a height distribution of the mask surface; a length measuring mechanism for measuring a shape of the transfer pattern on the pedestal to obtain a pattern length measuring data; And correcting the pattern length measurement data by using the mask surface shape data of the mask obtained in advance and the mask surface height distribution data; and comparing the frame, comparing the corrected pattern length measurement data with the rotation The design of the printed pattern depicts the data. An inspection device for a photomask for inspecting a photomask including a transfer pattern of a film on a transparent substrate, and comprising: a height measuring mechanism disposed on the pedestal by measuring the transfer pattern upward a height distribution of the surface of the reticle to obtain a height distribution of the mask surface; a length measuring mechanism for measuring a shape of the transfer pattern on the pedestal to obtain a pattern length measuring data; Using the mask surface shape data of the mask obtained in advance and the mask surface height distribution data to correct the design drawing data for the transfer pattern; and the comparison mechanism, which compares the corrected design depiction data with The above pattern is used to measure the length of the data.