JPH11202475A - Mask correcting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the size of a mask image transferred onto a semiconductor substrate owing to a black defect of a mask. SOLUTION: It is decided (b) whether a defect found by defect inspection (a) of the mask results from excessive chromium or an insufficient light shield part at an opening part. When the light shield part is excessive, the light shield part is removed temporarily a little large. Namely, correction is performed (c) so that the opening part is within the range between design size and (design size plus 2Δ), where ±Δ is the position precision of the correcting device. Then the size after actual correction is measured and a proper transmission rate of the correction part is determined. Here, light intensity simulation (d) is performed according to the result of size measurement (c) after correction to find proper transmissivity. Thus, what transmissivity the corrected auxiliary pattern needs to have so as to obtain the same effect with an ordinary fine auxiliary pattern is found. Then Ga ions are implanted in the corrected part by using FIB(focused ion beam) to adjust the transmissivity of the corrected part to a specific value (e).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for correcting a black defect in a transmission type mask having a light-shielding area and a transparent area, or a reflection type mask having a reflection area and an absorption area.

[0002]

[Prior art]

[0003] In the field of optical lithography, the miniaturization of semiconductor elements has been supported by shortening the wavelength of exposure light and increasing the NA of the projection lens. Here, NA is a numerical aperture, and is defined as NA = sin θ1 by the maximum incident angle θ1 of light on the image forming plane. On the other hand, when viewed on the mask side, of the light diffracted by the mask, the maximum angle θ2 entering the projection lens and the maximum angle θ2 on the previous image forming plane are M
xsin θ2 = sin θ1. here,
M is a reduction ratio of the projection lens.

Therefore, the NA corresponds to the angle at which the light diffracted by the mask can be collected. A larger NA means that light diffracted at a larger angle can be collected. To increase NA
We call it A.

If the mask pattern is a periodic pattern, a clear diffracted light is generated, and the angle θn of the n-th order diffracted light is s
in θn = nλ / P. Where λ is the wavelength of light, P
Is the pitch of the pattern. Of the light diffracted by the mask, the 0th-order diffracted light is light that travels straight in the same direction as the incident angle, and has information on average brightness. The information on the period of the pattern is included in the ± 1st-order diffracted light.

Therefore, at least these 0th order and ±
Unless the primary light 3 is collected, a pattern having the same cycle as the original mask pattern cannot be formed. When the pattern becomes finer (P becomes smaller), the angle of the diffracted light becomes larger, ± 1
The next light does not enter the projection lens, and the pattern is not resolved.

[0007] To collect the ± 1st-order diffracted light of a fine pattern, the wavelength is shortened by decreasing λ to reduce the diffraction angle, and the high NA to collect even a diffracted light of a larger angle.
Is necessary.

However, shortening the wavelength and increasing the NA increase the depth of focus (the range of the focal position at which the pattern is resolved), and securing a depth of focus is an important issue for further miniaturization of semiconductor devices. Become.

Therefore, a modified illumination method as described below has been proposed. The modified illumination method is a method of expanding the depth of focus by optimizing the shape of the effective light source that illuminates the mask. A modified illumination method has been proposed in which the incident angle of light illuminating the mask can be adjusted by adjusting the shape of the effective light source, and the depth of focus of the incident angle of light is increased. Here, the pattern on the mask is described as a periodic pattern. The principle of the modified illumination method will be described.

In a normal exposure method, a mask is illuminated with a circular effective light source, and there is light that is vertically incident on the mask. Then, as described above, the 0th order of the mask and ± 1
The secondary light 3 was collected and imaged (image formation by interference of three light beams).

On the other hand, in the modified illumination method, a part of an effective light source formed by a fly-eye lens is shielded from light by using a special stop. When the central portion of the fly-eye lens is shielded, no light is vertically incident on the mask, and all light is obliquely incident. When illuminated with oblique incident light, one of the ± 1st-order diffracted lights does not pass through the projection lens, and a pattern is imaged by the interference of one of the ± 1st-order diffracted lights and the 0th-order diffracted light (two-beam interference). Imaging). In the best focus, the contrast of the two-beam interference imaging is lower than that of the normal three-beam interference imaging because one of the ± first-order diffracted lights is discarded.

However, considering the angle of the incident light on the image forming surface, the image formed by the two-beam interference is １ ／ of the image formed by the three-beam interference, and the image blur due to the focal position shift is small. Become. Therefore, in the image forming method of two-beam interference, a decrease in the contrast of an image due to a change in the focal position is small, and the depth of focus can be increased.

However, the modified illumination method is effective only for periodic patterns, and is not effective for isolated patterns in which clear diffracted light does not occur.

Therefore, an auxiliary pattern mask as disclosed in Japanese Patent Application Laid-Open No. 4-268714 has been proposed. The auxiliary pattern mask is a mask in which a fine pattern that does not resolve itself (hereinafter, referred to as an auxiliary pattern) is arranged around a pattern to be transferred onto a semiconductor substrate (hereinafter, referred to as a main pattern). By arranging the auxiliary pattern, a somewhat strong diffracted light is generated,
An imaging state of light beam interference is realized. Therefore, the depth of focus of the isolated pattern (main pattern) can be enlarged to the same level as the periodic pattern.

However, the auxiliary pattern mask has a problem in the point of mask correction, and has not been put to practical use. Here, first, a conventional mask correction method will be described.

The mask defect includes a black defect (chrome remaining in an unnecessary portion) and a white defect (chromium remaining in an unnecessary portion), and the repair methods are different from each other.

First, the white defect is determined by FIB (focused).
Ion beam: FIB source used for mask correction is almost Ga at the present time, and gas containing carbon (C) is flowed so as to leave the carbon film in the lack of chromium. FIB
In one scan, the carbon number element is deposited on the FIB irradiating portion in a unit of several atoms, and the FIB is scanned a plurality of times to form a carbon film having a thickness capable of blocking exposure light. Generally, when deposited to a thickness of 200 nm or more, the exposure light can be completely blocked by the absorption effect of Ga contained in the carbon film.

The conditions of the FIB apparatus are generally such that the source is Ga, the acceleration voltage is 30 eV, and the ion current is about 45 to 130 pA.

On the other hand, in the case of a black defect, a method of evaporating chromium mainly using a laser beam has been used. Recently, a method of locally etching using a gas assist FIB has been studied. In the case of a normal FIB, since a non-etching material is hit by an ion so as to cut it, not only a chrome light-shielding film but also a synthetic quartz transparent substrate is cut. In addition, ions are implanted into the transparent substrate, which lowers the transmittance of the repair portion. This is called Ga stain.

However, by flowing a specific gas, G
Techniques have been proposed to suppress the occurrence of a stain and to improve the etching selectivity between chromium and a transparent substrate, and it has become possible to correct black defects by FIB.

[0022]

However, conventionally, it has been difficult to correct a fine pattern such as an auxiliary pattern. For example, FIG. 2 shows an example of a defect of the auxiliary pattern. In the auxiliary pattern mask shown in FIG. 2, 0.8 μm auxiliary patterns 2 are arranged at a pitch of 2 μm around a 1 μm main pattern 1 on the mask. And
As shown in the figure, one auxiliary pattern 2c is missing.

At present, when such a small hole pattern is opened by a repairing device (laser repair and FIB mask repairing device), the hole size after repairing has a variation of ± 0.2 μm or more. If the size of the auxiliary pattern after the correction becomes large, the auxiliary pattern is also transferred onto the semiconductor substrate (the auxiliary pattern is 0.9 μm
It is transferred when it becomes above.

On the other hand, when the auxiliary pattern after the correction becomes smaller, the main pattern is deformed and displaced. That is, the light intensity on the side where the auxiliary pattern has become smaller is reduced, so that the hole pattern is distorted. for that reason,
Conventionally, the dimensional variation after correction is large,
No corrections were made because the mask is unlikely to be usable.

An object of the present invention is to provide a mask repair method for repairing a mask so that the repair dimension is equal to a design value + Δ when the repair precision of the mask repair apparatus is ± Δ (currently about 0.15 μm). is there.

[0026]

In order to achieve the above object, a mask repairing method according to the present invention is a mask repairing method for a black defect of a transmission type mask in which a light-shielding region and a transparent region are formed. Correct the light-shielding area of the defective part so that it is smaller than the design size, then measure the repaired part size,
The transmittance of the transparent region near the repaired portion is reduced so that the transferred image at the repaired portion becomes a transferred image when there is no original defect.

A mask repair method according to the present invention is a mask repair method for a black defect of a reflective mask in which a reflection region and an absorption region are formed, wherein the absorption material of the black defect portion is smaller than a design size. After the correction, the dimensions of the corrected portion are measured, and the reflectance of the reflection area near the corrected portion is reduced so that the transferred image at the corrected portion becomes a transferred image when there is no original defect.

According to the present invention, in the correction of a black defect (a defect in which a light-shielding portion is enlarged: a convex defect, a collapse of an opening, etc.), the size of the transparent region is once corrected to be large.
Then, calculate the appropriate transmittance from the corrected dimensions,
By reducing the transmittance of the correction unit, the dimension of the mask image transferred onto the semiconductor substrate is corrected so as to have a target value.

Specifically, in the present invention,
As shown in FIG. 3, the correction accuracy of the mask correction device is ± Δ
If it is (currently about 0.15 μm), the correction is performed so that the correction dimension becomes the design value + Δ.

Therefore, the dimension after the correction is included in the range from the design value to the design value + 2Δ. here,
0.8 + 0.15 = 0.9 for the 0.8 μm auxiliary pattern
It has been corrected to be 5 μm. Then, the dimensions after the correction are actually measured by a length measuring SEM or the like, and the extent to which the transmittance should be reduced is obtained. This can be done by performing a light intensity distribution simulation or by using a mask evaluation device (MSM100 (AIMS: real im, manufactured by Carl Sites, Inc.).
age measurement system)
The transfer image of the mask may be directly observed by using.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment) FIG. 1 is a flowchart showing a mask repair method according to an embodiment of the present invention in the order of steps.

In the figure, a mask repairing method according to the first embodiment of the present invention is a mask repairing method for a black defect of a transmission type mask in which a light-shielding region and a transparent region are formed. Correct so that it is smaller than the design dimension, then measure the dimensions of the repaired part, and adjust the transmittance of the transparent area near the repaired part so that the transferred image at the repaired part becomes a transferred image when there is no original defect. It is characterized by lowering.

Next, the mask repair method according to the first embodiment of the present invention will be described in detail using a specific example.

First, as shown in FIG. 1, it is determined whether the defect found in the mask defect inspection (a) is extra chromium or the light-shielding portion at the opening is insufficient (b). .

If the light-shielding portion is excessive, the light-shielding portion is temporarily removed to a large size. That is, assuming that the positional accuracy of the correction device is ± Δ, the correction is performed so that the opening falls within the range of (design size + 2Δ) from the design size (c).

Next, the dimensions after the actual correction are measured,
Determine the appropriate transmittance of the correction section. Here, the light intensity simulation (d) is performed based on the result of the post-correction dimension measurement (c) to determine the appropriate transmittance (d).

Instead of the post-correction dimension measurement (c) and the light intensity simulation (d), it is also possible to directly observe the mask transfer image using a mask evaluation device such as MSM100. That is, a mask evaluation device such as the MSM100 has an optical system equivalent to an actual exposure device, and the exposure device projects a mask image on a semiconductor substrate in a reduced size, while the mask image is enlarged and projected on a CCD, thereby forming a mask. This is because a transferred image can be directly observed.

In this way, it is determined how much the transmittance of the corrected auxiliary pattern can provide the same effect as a normal fine auxiliary pattern. Then, Ga ions are implanted into the correction portion using the FIB, and the transmittance of the correction portion is adjusted to a predetermined value (e). In the case where the light-shielding portion is insufficient from the beginning in the opening dimension correcting step (b), the corrected dimension measuring step (c) is omitted, and the light intensity simulation step (d) and the transmittance adjusting step ( e).

Next, an example of the mask repair method according to the first embodiment of the present invention will be described with reference to the drawings.

FIGS. 2, 3, 4 and 5 are views showing an embodiment of a mask repairing method according to the present invention in the order of steps. Hereinafter, the exposure apparatus used is a reduction rate of 1/5, NA = 0.
5, σ = 0.8, 70% annular illumination (center 70 of effective light source)
% Is shaded) as a KrF excimer laser exposure apparatus.
The case where an auxiliary pattern mask for forming a 0.2 μm hole pattern on a semiconductor substrate is modified will be described.

As shown in FIG. 2, the mask pattern is such that a light-shielding film 102 is formed on one surface of a transparent substrate 101, and an opening is provided in the light-shielding film 102 to form a hole-shaped main pattern 1 and auxiliary patterns 2a to 2g. This is configured as an auxiliary pattern mask in which a hole-shaped main pattern 1 of 1 μm and auxiliary patterns 2 a to 2 g of 0.8 μm are arranged therearound. As shown in FIG. 2A, the auxiliary pattern 2c on the right side among the auxiliary patterns 2a to 2g has an unresolved pattern due to the influence of a foreign matter during mask drawing.

First, as shown in FIG. 3, the auxiliary pattern 2c is corrected to be relatively large by the laser repair method. Here, “large” means that at least the auxiliary pattern has the design size in consideration of the positional accuracy of the mask repair device (laser repair, gas assist FIB device). Specifically, the position accuracy of the laser repair device is currently ± 0.
The auxiliary pattern 2c is 15 μm (on the mask).
Is enlarged and corrected from 0.8 μm to 1.1 μm.

Next, as shown in FIG. 4, the dimensions of the corrected mask 2c are measured, and a light intensity simulation is performed.
Here, the auxiliary pattern 2c after the correction is 1 μm on the mask.
Suppose that it was a hole of m.

In FIG. 4, the center peak is the main pattern 1 (horizontal axis −100 to +100 nm), the peak on the right side is the corrected auxiliary pattern 2c, and the left side is the peak of the normal auxiliary pattern.

As a method of predicting a resist pattern from a light intensity distribution, generally, an exposure threshold model (Exposure threshold) is used.
model), which is a simple resist development model.
This is because, in the light intensity distribution, a portion having a certain intensity (hereinafter, this intensity is referred to as Ith) or more is removed by development, and
The part below th is a model that assumes that it will not melt even when developed.

In FIG. 4, Ith is set to 0.185 to open the main pattern to 0.2 μm. And the peak intensity of the normal auxiliary pattern is
Since it is 0.159, the auxiliary pattern is not transferred onto the resist. However, the modified auxiliary pattern 2
The light intensity distribution of c has a higher intensity than Ith and is transferred onto the semiconductor substrate. Further, it can be seen that the light intensity of the main pattern is left-right asymmetric, and deformation and displacement of the main pattern occur.

In order to prevent the transfer of the corrected auxiliary pattern and to prevent deformation and displacement of the main pattern, it is necessary to make the light intensity of the corrected auxiliary pattern the same as that of a normal auxiliary pattern. The peak intensity of the normal auxiliary pattern is 0.1
59, and the peak intensity of the corrected auxiliary pattern is 0.5.
Since it is 282, the transmittance of the corrected auxiliary pattern should be 0.159 / 0.282 × 100 = 56%.

Therefore, as shown in FIG. 5, the location of the corrected auxiliary pattern 2c is scanned by FIB a predetermined number of times.
By implanting Ga ions, the transmittance of the auxiliary pattern 2c is reduced. For this purpose, the relationship between the number of FIB scans and the transmittance is determined in advance.

The wavelength of the KrF excimer laser light (248
nm), Photomask and X-ray
Mask Technology 3, pages 336-345, 1
996 (Photomask and X-ray
Mask Technology III, p. 33
6-345, 1996) discloses the relationship between the FIB irradiation amount (ion / cm ² ) and the transmittance for a wavelength of 250 nm, and such data can be used. According to this data, the transmittance at the dose 10 ¹⁶ 75
%, The transmittance decreases to about 55% when the irradiation amount is 2 × 10 ¹⁶ .

If the positional accuracy of the correction device is ± Δ, the correction target dimension is set to (design value + Δ), and the auxiliary pattern 2c is opened to a size larger than the design value. Then, as shown in FIG. 4, the dimensions of the corrected auxiliary pattern 2c are measured, and the light intensity is calculated. When the corrected auxiliary pattern 2c is transferred, the transmittance of the auxiliary pattern 2c is reduced by using the FIB as shown in FIG.

Although the corrected auxiliary pattern 2c is fine, since the auxiliary pattern 2 itself is not a transferred pattern, there is no problem even if the size is slightly distorted, and it is possible to make the opening larger. Then, the transmittance of the corrected auxiliary pattern 2c is reduced so that the peak intensity of the auxiliary pattern 2c is the same as that of the other auxiliary patterns in the light intensity distribution on the image forming surface.
The transfer of the corrected auxiliary pattern 2c is prevented. In this way, the auxiliary pattern 2c having a large size and a low transmittance has an effect equal to or more than that of a normal fine auxiliary pattern, and the depth of focus of the main pattern 1 does not decrease.

Next, the light intensity distribution of the mask corrected by the mask correcting method according to the present invention will be described. First, FIG. 6 shows the light intensity distribution when the auxiliary pattern portion is greatly opened to 0.19 μm and 0.2 μm in the process of FIG. 6, the horizontal axis (x) is the image plane (position on the semiconductor substrate), and the vertical axis (y) is the relative light intensity. The relative light intensity is the light in a sufficiently wide transparent region without a pattern. It is a value normalized with the strength as 1.

FIG. 6A shows the case where the dimension after modification is 0.18 μm (0.95 μm on the mask), and FIG.
(1 μm above the mask).

FIG. 6A shows the corrected auxiliary pattern 2c.
FIG. 6B shows the light intensity when the opening size of the modified auxiliary pattern 2c is 0.2 μm (1 μm on the mask) when the opening size is 0.18 μm (0.95 μm on the mask). is there.

As shown in FIG. 6, when the auxiliary pattern 2c has a thickness of 0.18 μm or more, the light intensity at the auxiliary pattern 2c becomes the light intensity level (Ith = 0.185) that opens the main pattern 1 to 0.2 μm. , And the correction assist pattern 2c is transferred.

Therefore, in the mask repair method according to the embodiment of the present invention, the transmittance of the repaired auxiliary pattern 2c is reduced by the FIB. FIG. 7 shows a light intensity distribution after transmittance correction. FIG. 7A shows the corrected auxiliary pattern 2c.
Is a result obtained by enlarging the opening size to 0.18 μm and correcting the transmittance of the auxiliary pattern to 73%. FIG. 7B shows the result of reducing the transmittance of the auxiliary pattern, which has become 0.2 μm after correction, to 56%, which is also shown in the previous embodiment. In each case, the peak of the auxiliary pattern is Ith
(0.185) or less, indicating that transfer is prevented.

Further, the mask repairing method of the present invention does not affect the exposure characteristics of the main pattern, and can secure the same depth of focus (the range of the focus position where the resist pattern can be resolved) as in the case where there is no defect.

Here, a light intensity distribution simulation as shown in FIG. 7 was performed by changing the focal position, and the contrast was defined as follows. Contrast = Imax / Ie
dge Here, Imax is the maximum light intensity of the main pattern portion at each focal position, and Iedge is the light intensity at the pattern edge position at the best focus. The use of this Iedge corresponds to setting the exposure amount so that the resist pattern dimension becomes the target dimension at the best focus.

The resolution and resolution of the resist pattern depending on the number of defined contrasts largely depend on the resist characteristics, and are usually 1.7 to 1.3 (higher resolution resists are resolved with lower contrast). Here, the resist pattern can be resolved with a contrast of 1.4 or more.

FIG. 8 shows the relationship between the contrast of each mask pattern and the focal position. In the case of a normal mask that does not use an auxiliary pattern, the depth of focus is ± 0.3 μm. And
In the auxiliary pattern mask using the auxiliary pattern (auxiliary pattern size = 0.16 μm, pitch = 0.4 μm), the depth of focus is expanded to ± 0.45 μm. However, in the case of an auxiliary pattern mask in which one of the auxiliary patterns is missing (having a defect), the effect of the auxiliary pattern method is significantly reduced, and the depth of focus is reduced to the same level as a normal mask.

In the present invention, since the missing auxiliary pattern 2c is once greatly opened and its transmittance is adjusted, the depth of focus is equal to that of the original auxiliary pattern mask without defects. In the figure, the three lines without the defect and the three lines after the correction are overlapped.

(Embodiment 2) Next, Embodiment 2 of the present invention
Will be described with reference to the drawings. Embodiment 2 of the present invention
Is a method of repairing a black defect of a reflection type mask in which a reflection region and an absorption region are formed, wherein the absorption material of the black defect portion is corrected to be smaller than a design size, and thereafter,
The feature of the present invention is characterized in that the size of the repaired portion is measured, and the reflectance of the reflection area near the repaired portion is reduced so that the transferred image at the repaired portion becomes a transferred image when there is no original defect.

Embodiment 2 of the present invention will be specifically described. As shown in FIG. 9, the reflective mask for reduced X-ray exposure according to the second embodiment of the present invention is a silicon substrate 110
A multilayer coating mirror 111 in which two materials having different refractive indices are alternately laminated is formed thereon. The X-ray absorbing material (heavy metal such as Ta, W, Au, etc.) 112
This is a reflection type mask in which a reflection area 4 and an absorption area 3 are formed.

As shown in FIG. 9, a description will be given of the correction of the convex defect 5 in which an unnecessary projection is generated in a part of the line pattern of the absorption region 3.

First, as shown in FIG.
Is used to remove the absorbing material 112 of the convex defect 5 once. Here, if the correction accuracy by the FIB is ± Δ, the line width after the correction is set to (design value−Δ). Therefore, the dimension after correction is (design value−2Δ
To (design value).

Then, as shown in FIG. 10B, the semiconductor substrate 113 coated with the positive resist 114 is exposed using this mask, and the line width of the repaired portion is measured. In the modification using the FIB, ions are implanted at the time of the modification, and the reflectivity of the multilayer coating mirror 111 may be reduced.
In addition, exposure using this mask is performed, and a change in reflectance is confirmed from the transfer result.

Then, as shown in FIG. 11A, the reflectivity of the repaired portion is reduced by implanting Ga ions into the defect repaired portion by FIB (Ga stain 6), and the line width is made the same as the other portions. To be. The multilayer coating mirror 111 realizes a high reflectance by aligning the phases of the X-rays reflected at each boundary of the multilayer structure.
If the refractive index is changed by implanting another material such as Ga in the IB, the reflectance decreases. In addition, by hitting with FIB ions, the transmittance is reduced even if several layers of the mirror 111 are cut. Also, while flowing the deposition gas,
The reflectivity can also be reduced by irradiating the FIB around the correction portion and depositing an X-ray absorbing material (W or the like).

As described above, the absorption material 112 is temporarily cut to a large size, the Ga stain 6 is generated from the corrected transfer result, and the reflectance is corrected.
As shown in (b), the line width at the correction point can be appropriately adjusted.

[0070]

As described above, according to the present invention, in correcting a black defect (a defect with a large light-shielding portion: a convex defect, a collapse of an opening, etc.), the size of the transparent region is temporarily increased. By correcting and appropriately lowering the appropriate transmittance from the size after the correction, the size of the mask image transferred onto the semiconductor substrate can be corrected to a desired value.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a mask repair method according to an embodiment of the present invention in the order of steps.

FIG. 2A is a plan view showing a defect of a mask, and FIG.
Is a sectional view of the same.

FIG. 3A is a plan view showing a step of correcting a mask defect, and FIG. 3B is a sectional view of the same.

FIG. 4 is a diagram illustrating a process of measuring a dimension of a mask after correction and performing a light intensity simulation.

FIG. 5A is a plan view showing a process for correcting a defect of a mask, and FIG. 5B is a sectional view of the same.

FIG. 6 is a diagram showing a process of measuring the dimensions of the mask after correction and performing light intensity simulation.

FIG. 7 is a view showing a process of measuring a dimension of a mask after correction and performing a light intensity simulation.

FIG. 8 is a diagram showing the relationship between the contrast and the focus position of each mask pattern.

9A is a plan view showing a step of correcting a mask defect, and FIG. 9B is a sectional view of the same.

FIG. 10A is a plan view illustrating a process of correcting a defect of a mask, and FIG. 10B is a diagram illustrating a process of performing an exposure process using the corrected mask.

FIG. 11A is a plan view illustrating a process of correcting a defect of a mask, and FIG. 11B is a diagram illustrating a process of performing an exposure process using the corrected mask.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main pattern 2a-2g Auxiliary pattern 3 Absorption area 4 Reflection area 5 Convex defect 6 Ga stain

Claims (2)

[Claims] 1. A method for repairing a black defect of a transmission type mask having a light-shielding region and a transparent region formed therein, wherein the light-shielding region of the black defect portion is repaired so as to be smaller than a design size. A mask repair method comprising measuring dimensions, and reducing transmittance of a transparent region near a repair portion so that a transfer image at a repair portion becomes a transfer image when there is no original defect. 2. A method of repairing a black defect in a reflective mask having a reflection region and an absorption region formed therein, wherein the absorption material of the black defect portion is repaired so as to be smaller than a design size, and then the repair location is corrected. A mask repairing method comprising measuring dimensions and reducing a reflectance of a reflection area near a repaired portion so that a transferred image at a repaired portion becomes a transferred image without an original defect.