JPH09160221A - Method for correcting shifter defect of phase shift mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct the shifter defect existing in a phase shift mask with good accuracy, efficiency and productivity and to obviate the imaging of the unnecessary pattern occurring in this shifter defect by exposure and transfer. SOLUTION: The correction of the shifter defect which exists in light transparent part or phase shift part, has a projecting shape and has a phase shift characteristic is executed by first applying a negative type photoresist 4 on the pattern surface side of a substrate 1 and exposing this resist from the opposite surface side of the substrate 1 to shield the light in the edge part of at least the shifter defect in self-alignment and to hold this part unexposed, then developing the resist to form the resist pattern. Next, the shifter defect of the projecting shape existing in the aperture of the resist pattern is etched down to the phase surface equal to the local region where the shifter defect exists and, thereafter, the resist pattern is removed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to LSI, VLSI,
Exposure transfer when forming a fine pattern (or a fine structure) of micron to sub-micron order or smaller dimension by photolithography, including manufacturing of semiconductor integrated circuits represented by ULSI and the like, micromachines, etc. In particular, the present invention relates to a phase shift mask using a phase shift technique, and relates to a technique suitable for correcting a shifter defect.

[0002]

2. Description of the Related Art Phase shift mask technology is a kind of so-called super-resolution technology in photolithography technology and has been actively developed in recent years. This is a photomask that includes not only the light-transmitting part and the light-shielding part like a conventional photomask, but also a phase shift part that reverses the phase of the transmitted light, and is dramatically superior to the conventional mask. It has been clarified that it has the effect of improving the resolution and the depth of focus of fine patterns. In particular, a phase shift method using a method of improving the resolution of a fine pattern by setting the phases of the projection lights passing through adjacent patterns to 180 degrees is called a frequency modulation type or Levenson type, and this principle is based on the IBM standard. No. 58-173744, and the principle is described in JP-B-62-50811.

The so-called frequency modulation type (or Levenson type) phase shift mask as described above has a phase inversion action when the phase difference of light transmitted through the phase shift layer is about 180 degrees with reference to the transparent substrate surface. The characteristic is to have. This phase reversal action causes the phase difference of transmitted light to be 180
Theoretically, it is maximum that the degree, that is, the phase difference is half the wavelength. Incidentally, conventionally, a “photomask” refers to a photomask that performs exposure and transfer at an equal magnification, and a photomask that performs exposure and transfer at a reduction magnification is often referred to as a “reticle”.
In the case of the phase shift mask according to the present invention, there are those that perform exposure and transfer at the same magnification and those that perform exposure and transfer at a reduction magnification. In the present specification, "phase shift mask" is referred to as either of these. The name also means the case of.

FIG. 2 is a sectional view of a conventional Levenson type phase shift mask. In principle, the light transmitting portion, the light shielding portion, and the phase shift portion need only be two-dimensionally present, so there are several types of cross-sectional structures that have the same phase shift effect, other than those shown in FIG. There is. FIG. 2A shows a typical structure thereof, in which a light shielding pattern 12 is provided on a transparent substrate 11,
The phase shift section 13 is formed by etching the transparent substrate by an amount corresponding to a phase difference of 180 degrees. In FIG. 2B, the etching stopper layer 14 is used for controlling the etching when forming the phase shift portion.
It is provided under 3 '. FIG. 2C shows the phase shift layer 1
3 "is provided on the light shielding pattern 12. In any case,
The phase difference of the transmitted light (the phase difference between the light p1 passing through the light transmitting portion and the light p2 passing through the phase shift portion) is made to be 180 degrees.

Next, the manufacturing process of the conventional phase shift mask will be described. FIG. 4 shows a conventional manufacturing process of the phase shift mask having the structure shown in FIG. First, as shown in FIG. 4A, a light shielding layer 32 'is formed on the transparent substrate 31.
Is provided and a positive type electron beam resist 34 is applied thereon, and then electron beam drawing 35 of a light shielding pattern is performed. Next in FIG.
After the development in (b) to obtain a resist pattern 34 ', the light shielding layer is etched to form the light shielding layer pattern 32.
Get. In FIG. 4C, the remaining resist is removed, the electron beam resist 36 is applied again, and electron beam superposition drawing 37 of the phase shift pattern is performed. Here, the superposition drawing is one in which, in order to arrange the previously formed light-shielding pattern and the phase shift pattern as designed, the superimposition mark of the light-shielding pattern is detected at the time of drawing, the drawing position is aligned, and the drawing is performed. Is.

Subsequently, in FIG. 4D, the transparent substrate is etched by using the resist pattern obtained by the development as a mask to obtain a phase shift pattern 33. And FIG.
The remaining resist is removed as shown in (e) to obtain a phase shift mask.

In the manufacturing process of the phase shift mask having such a structure, a defect may actually occur, which naturally needs to be corrected. Regarding such defects, there are the following methods as conventional repair methods. First, the defect of the light-shielding pattern can be inspected and repaired in the same manner as the mask defect of the normal light-shielding pattern only, and normally, the remaining defect can be repaired by evaporating the defect using a laser repairing device. If the defect is a missing defect, it can be corrected by depositing carbon on the defective part using a focused ion beam device. To fix these defects,
It suffices to simply correct the portion to be shielded from light or to transmit the portion to be transmitted, and the conventional correction method has no problem unless it is a particularly large defect.

However, in the phase shift mask as described above, a transparent or semitransparent defect (shifter defect) may be generated in the phase shift part or the light transmitting part as shown in FIG. This is caused by the fact that the portion to be etched is not etched or the non-etched portion is etched in the etching process of the phase shift portion, and the material is the same as the material of the phase shift portion. In the case of the structure shown in FIG. 2A, it is the same as the substrate material. The semitransparent defect occurs in the case of what is called a phase shift mask having a semitransparent phase shifter, that is, a halftone type phase shift mask.

FIG. 3 is a diagram showing that a shifter defect exists in the structure of FIG. 2 (a). FIG. 3A shows a convex shifter defect, in which the light shielding layer pattern 22 is formed on the transparent substrate 21.
And a phase shift pattern 23 is formed, and a convex shifter defect 24 is present in the phase shift pattern. FIG. 3B shows a concave defect, which has the same configuration as that of FIG. 3A, but has a concave shifter defect 25 in the light transmitting portion. These shifter defects are defects that are generated in the manufacturing process of the phase shift pattern, and have a characteristic that the exposure transfer property is very high as compared with the defects of the light shielding pattern. Therefore, minute defects are not allowed in terms of quality.

Since the phase difference of the shifter defect as shown in FIG. 3 is almost 180 degrees, the phase of the transmitted light is inverted with the edge portion of the defect as a boundary, and the light intensity at the boundary becomes zero. . Therefore, compared with the defect of the light shielding pattern,
Even a defect having a smaller size has a high transferability, and it has been found from experiments that the transferability of a shifter defect reaches about twice that of a light-shielding defect depending on the defect size ratio.

However, although the existence of such a shifter defect is disadvantageous in terms of mask quality, it is technically difficult to correct the shifter defect. Because the shifter defect is transparent, the defect inspection device using transmitted light as in the past cannot be used, and it is difficult to detect the defect. Even if an attempt is made to correct (remove) with a device, the thermal energy of the laser is not accumulated in the convex defect portion and there is no effect (the convex defect cannot be removed satisfactorily), or it is the same as the phase shift portion to fill the concave defect. This is because it is extremely difficult to deposit the material only on the concave defect portion, and this is because there is a firm reason for this.

The above-mentioned problems are caused by the above-mentioned FIG.
The structure (c) does not change at all. Therefore, it is extremely difficult to accurately correct the shifter defect even when manufacturing a single piece for an experiment, and it is possible to correct the shifter defect accurately and efficiently in the commercial level production, and further with high productivity. That was even more difficult.

[0013]

SUMMARY OF THE INVENTION The present invention has been made by paying attention to the problems of the above-mentioned conventional techniques, and an object of the present invention is to accurately remove the shifter defect existing in the phase shift mask, It is an object of the present invention to provide a correction method capable of performing correction efficiently and with good productivity so that an unnecessary pattern is not imaged due to the shifter defect due to exposure and transfer.

[0014]

[Means for Solving the Problems] Means provided by the present invention for solving the above problems are as follows.
As shown in (1), when correcting a shifter defect that exists in the light transmission part or the phase shift part and has a convex shape and has a phase shift property, (a) use a negative photoresist on the pattern surface side of the substrate. After coating, by exposing from the opposite surface side of the substrate, at least the edge portion of the shifter defect is shielded from light in a self-aligned manner to be unexposed, and then developed to form a resist pattern,
(B) After that, the convex shifter defect in the opening of the resist pattern reaches a depth almost equal to the original phase plane of the light transmission part or the phase shift part in which the shifter defect exists. To remove the resist pattern after etching up to (a)
A method for repairing a shifter defect of a phase shift mask, characterized by comprising:

Alternatively, as described in claim 2, when repairing a shifter defect which is present in the light transmitting portion or the phase shift portion, has a concave shape, and has a phase shift property,
(C) After applying a negative photoresist to the pattern surface side of the substrate, by exposing from the opposite surface side of the substrate, at least the edge portion of the shifter defect is shielded in a self-aligned manner and left unexposed, Next, the step of developing to form a resist pattern, (d) after which, the concave shifter defect in the opening of the resist pattern is removed.
After removing by etching to a depth that is approximately equivalent to the amount of phase shift of the original phase shift part,
A method of repairing a shifter defect of a phase shift mask, comprising the steps (c) and (d) of removing the resist pattern.

Alternatively, as described in claim 3, there is a shifter defect having a phase shift property, which exists in the light transmitting portion or the phase shift portion, and has a convex shape in the same phase shift mask. In the case of correcting a shifter defect in which both a concave shape and a concave shape are present, (e) at least the above-mentioned two types are obtained by applying a negative photoresist to the pattern surface side of the substrate and then exposing from the opposite surface side of the substrate. The edge portion of the shifter defect of the shape is shielded in a self-aligned manner so as to be unexposed, and then developed to form a resist pattern. (He) After that, both of the shapes in the opening of the resist pattern are formed. The shifter defect is removed until the convex-shaped shifter defect reaches a depth almost equal to the original phase plane of the light transmission part or the phase shift part in which it exists. After removal by quenching a said step of removing the resist pattern, or (e) and the shifter defect correction method of the phase shift mask, characterized by comprising (f).

Alternatively, as described in claim 4, there is a shifter defect which exists in the light transmitting portion or the phase shift portion and has a phase shift property, and has a convex shape in the same phase shift mask. In the case of correcting a shifter defect in which both the concave shape and the concave shape are present, (g) at least the above-mentioned both are obtained by applying a negative photoresist on the pattern surface side of the substrate and then exposing from the opposite surface side of the substrate. The edge portion of the shape shifter defect is shielded from light in a self-aligned manner and left unexposed, and then development is performed to form a resist pattern. (H) After that, both of the shapes in the opening of the resist pattern are formed. The shifter defect is etched until the concave shifter defect is deepened by a depth corresponding to the phase shift amount of the original phase shift portion. After removal What is the resist removing the pattern, or (g) and the shifter defect correction method of the phase shift mask, characterized by comprising (h).

According to each of the first to fourth aspects, it is possible to expose all the shifter defect portions in a self-aligning manner at a time without performing the step of detecting the shifter, and at the same time, other Since the protective layer against etching after this is formed in the portion, the step of detecting defects and the step of correcting defects one by one are unnecessary, which is preferable.

It should be noted that the negative photoresist described in the claims must (of course) have good sensitivity to the wavelength of the light source used for exposure from the side opposite to the substrate.
Then, it is important to use a high-resolution resist that can be properly resolved by the light-shielding effect by the edge. As an exposure light source when performing exposure and transfer using the phase shift mask, an ultraviolet (particularly i-line) light source is generally widely used in consideration of the advantage and convenience of forming a fine pattern.
In addition, many negative photoresists for ultraviolet rays (particularly for i-rays) are already on the market and are suitable for use in the present invention. Further, tentatively, as the exposure light source when the exposure transfer is performed using the phase shift mask, a light source other than the above-mentioned ultraviolet light (a KrF laser or an ArF laser is mentioned as a good example of a light having a wavelength shorter than the ultraviolet light) is used. In that case, the photoresist for it is used suitably.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION As described in the section of the prior art, in the conventional shifter defect repairing method for a phase shift mask, when a shifter defect having a convex shape is repaired by using a laser repairing device, the shifter defect is corrected. Since the defects are transparent, thermal energy of the laser is not accumulated and cannot be repaired, and there is a problem that a material equivalent to the shifter material cannot be deposited to fill the concave shifter defect.
According to the shifter defect repairing method of the present invention, by exposing from the opposite surface side of the substrate, a negative resist is arranged on the side farther than the shifter defect on the optical path of the exposure light, and the edge light shielding exhibited by the shifter defect itself. Form a resist pattern opening at least at the edge part of the shifter defect, and prevent the original phase shift part from being etched in the process for this correction, and then form the phase shift part. By removing the shifter defect (at least the edge part) by etching using the same etching method as the above, the defect can be repaired without using an inspection device or a repair device, which is costly and has a large process load, in a process that can be performed extremely easily and in a short time. You can do it. Incidentally, when the shifter defect is so large that the entire one shifter defect is not shielded at one time only by the edge light shielding effect, the present invention is repeated a proper number of times so that the entire one shifter defect becomes once only by the edge light shielding effect. Is shielded from light and is gradually removed from the edge portion until the entire one shifter defect is exposed from the opening of the resist pattern and the entire one shifter defect is removed by etching.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The manufacturing process of the present invention will be described in more detail below with reference to the accompanying drawings.

<Embodiment 1> FIG. 1 is a diagram showing a first embodiment of the present invention. FIG. 1A is a sectional view of a Levenson-type phase shift mask on which a pattern has been formed, and the structure is shown in FIG. 2A. The manufacturing process up to the pattern formation is shown in FIG. 4, and the light shielding pattern 2 and the phase shift pattern 3 are formed on the transparent substrate 1. However, FIG. 1A shows that a convex shifter defect 5 is generated in the phase shift pattern 3 during the manufacturing process, which is the same as FIG. 3A.

The mask manufactured here is a phase shift mask for the i-line exposure process (exposure wavelength 365 nm), and has a quintuple pattern corresponding to a 1/5 projection exposure apparatus, and is called a 5 × reticle. Sometimes. FIG. 1 (a)
The width of the light-shielding pattern 2 is 1.5 μm, the phase shift pattern 3 is 1.5 μm, and the width of the shifter defect is about 0.5 μm.
m. The etching depth a of the phase shift portion corresponds to a phase difference of about 180 degrees at an exposure wavelength of 365 nm. 3
80 nm (converted as the refractive index of the substrate material = 1.475)
Met. Regarding the material, a synthetic quartz substrate is used as a transparent substrate, and a laminated film of chromium and chromium oxide (film thickness 1
10 nm) was used.

A method of repairing the shifter defect is shown in FIG. First, as shown in FIG. 1B, a negative photoresist 4 (film thickness 500 n is formed on the entire pattern surface of the substrate.
m) was applied, and after prebaking, exposure 6 was performed from the side opposite to the patterned surface of the substrate under a predetermined exposure condition using a contact mask exposure apparatus. At this time, in order to perform exposure from the opposite surface side, the mask substrate may be turned over and loaded into the apparatus as usual. By this method, the pattern of the phase shift mask itself is transferred and exposed on the negative type photoresist to form a latent image of a light-shielding pattern. The shifter defect, which is, is also transferred and a latent image of the defect is formed.

The reason is that the edge of the shifter pattern is exposed in the light transmitting portion without being hidden by the light shielding portion,
This is because the edge of the shifter has a property that the light intensity of the transmitted light is always 0 as a boundary portion where the phase is inverted. The shifter defect is also generated during the shifter pattern formation, and often has a phase difference of close to 180 degrees, and the transfer property is extremely high because the edge portion of the shifter defect has a considerably sharp light intensity change. The back exposure method also provides a latent image that can be sufficiently resolved.

Subsequently, as shown in FIG. 1C, a resist pattern 4'is formed by predetermined development. Since the resist pattern was a negative type resist, the resist remained only on the exposed portion, and the resist on the light-shielding pattern and on the shifter defect having the light-shielding effect for the above reason was removed. Next, in this state, etching 7 was performed under the same conditions as in the shifter pattern forming step. At this time, the light transmitting portion and the phase shift portion were covered and protected with a resist except the shifter defect portion, and only the exposed shifter defect was etched. As the etching method, dry etching using a parallel plate type reactive ion etching apparatus (parallel plate type RIE apparatus) was performed. The dry etching conditions are C ₂ F ₆ gas and H ₂ gas, and the mixing ratio is C _{2
F 6: H 2 = 10:} 1, power 300 W, gas pressure 0.0
It was set to 3 Torr. The etching time was about 15 minutes. As an etching method, a method of performing wet etching using a buffered hydrofluoric acid solution (BHF) for SiO ₂ etching can also be used.

FIG. 1 (d) shows a state after etching, in which the shifter defect is etched and becomes almost flush with the surrounding phase shift pattern, and the defect is eliminated. FIG.
In (e), the remaining resist was removed to obtain the desired phase shift mask with the defects corrected.

Using the mask obtained in this Example 1,
A reduction projection exposure device (exposure wavelength 365 nm) was used to expose the wafer under predetermined conditions to form a resist pattern. As a result, the defect was not transferred and resolved even in the portion where the corrected convex shifter defect was present, and 0.3
The μm pattern was well resolved, and a good and highly accurate pattern was obtained with the originally expected resolution.

<Second Embodiment> FIG. 5 is a view showing a second embodiment of the present invention. FIG. 5A is a cross-sectional view of a Levenson-type phase shift mask, in which a light shielding pattern 42 and a light transmitting portion 43 are formed on a transparent substrate 41. Further, it is shown that a convex shifter defect 45 is generated in the light transmitting portion 43 in the light transmitting portion 43, which is the same as FIG. 3B.
The depth b of the shifter defect 45 corresponds to a phase difference of 180 degrees. A negative photoresist 44 is applied to the entire pattern surface of the substrate, prebaked, and then exposed 46 under a predetermined exposure condition from the side opposite to the pattern surface of the substrate using the back exposure method shown in the first embodiment. went. As a result, a latent image of the light-shielding pattern of the phase shift mask is formed on the negative photoresist 44. At this time, the transparent shifter defect is also transferred for the above reason to form a latent image. Was done.

Next, as shown in FIG. 5B, a resist pattern 44 'was formed by predetermined development. Since the resist pattern 44 'uses a negative resist,
The resist remained only on the exposed portion, and the resist on the light-shielding pattern and on the shifter defect having a light-shielding effect due to the edge was removed. Next, etching 47 was performed under the same conditions as in the shifter pattern forming step. At this time, the light transmitting portion and the phase shift portion were covered and protected with a resist except the shifter defect portion, and only the exposed shifter defect was etched.

FIG. 5C shows a state after the defect correction etching, in which the concave shifter defect is etched deeper. However, since the etching amount is the same as when the shifter having a phase difference of 180 degrees is formed, the defect depth b ′ after etching is added to the original 180 degrees by 180 degrees,
The depth was equivalent to 360 degrees. The phase difference of 360 degrees corresponds to one wavelength. At this time, the phase shift effect is completely eliminated, and the phase difference becomes equal to 0 degree. Therefore, in this case, the defect is apparently deeper, but the phase inversion due to the shifter defect is zero, and the light shielding effect of the edge is also lost, which is equivalent to no defect. Finally, as shown in FIG. 5D, the remaining resist was removed to obtain a phase shift mask.

Using the mask obtained in this Example 2,
A reduction projection exposure device (exposure light source wavelength 365 nm) was used to perform exposure and transfer onto a wafer under predetermined conditions to form a resist pattern. As a result, the defect was not transferred and resolved even in the portion where the corrected concave shifter defect was present, and a good and highly accurate pattern was obtained with the resolution originally expected at the time of design.

In the methods shown in the above two embodiments, the film material, the kind of resist, the film forming method, the exposure method, the etching method, etc. are not limited to these, but generally, It is sufficient that the same performance as is obtained. Further, the structure of the mask is not limited to the above example. For example, as the material, a general metal compound film such as chromium, chromium oxide, or molybdenum silicide can be used for the light-shielding film, and SiO _x (where x is oxygen is used for the shifter material other than that by etching the substrate). X depends on the abundance of atoms
It is a real value of> 0. Example: SiO ₂ ), aluminum oxide, hafnium oxide, calcium fluoride, magnesium fluoride, spinel and other transparent materials can be used.

[0034]

The shifter defect repairing method for a phase shift mask according to the present invention uses a negative photoresist and a back exposure method and utilizes the light-shielding property of the shifter defect itself. It is possible to expose the edge part) and prevent the original phase shift part from being etched by the resist pattern or the light shielding layer pattern. In addition, shifter defects (small shifter defects are small) are formed by the same etching process as in the formation of the phase shift pattern. Sometimes, it was possible to remove all of them at once with high accuracy, or (when the shifter defect was too large to remove all at once) to remove them little by little but with accuracy. These can be efficiently performed because the portions to be removed by etching appear in the resist pattern openings in a self-aligned manner. Therefore, the conventional process of detecting shifter defects and selectively correcting the shifter defects one by one is not required, which eliminates the technical difficulty and is significantly advantageous in terms of cost and process load.

Further, when the mask obtained by the present invention was used for exposure and transfer onto a wafer, an unnecessary pattern due to a shifter defect was not imaged by exposure and transfer, and the original phase shift effect was obtained. The effect that the pattern is accurately formed is obtained. After all, the shifter defects present in the phase shift mask are
It has been possible to provide a correction method capable of performing correction with high accuracy, high efficiency, and high productivity, and preventing an image formation of an unnecessary pattern due to the shifter defect due to exposure and transfer.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a “shifter defect correcting method for a phase shift mask” according to the present invention.
(A)-(e)

FIG. 2 is a cross-sectional view showing the structure of a conventional Levenson-type phase shift mask. (A) to (c)

FIG. 3 is a cross-sectional view showing a case where a conventional phase shift mask has a defect. (A)-(b)

FIG. 4 is a cross-sectional view showing a manufacturing process of a conventional phase shift mask. (A)-(e)

FIG. 5 is a cross-sectional view showing a second embodiment of the shifter defect repairing method for the phase shift mask of the present invention. (A) ~
(D)

[Description of sign]

 1, 11, 21, 31, 41 ... Transparent substrate 2, 12, 22, 32, 42 ... Shading pattern 3, 13, 23, 33 ... Phase shift pattern 4, 44 ... Negative photo Resist 4 ', 44' ... Negative photoresist pattern 5, 24, 25, 45 ... Shifter defect 6, 46 ... Exposure 7, 47 ... Phase shift layer etching 13 '... Phase shift Pattern 14 ... Etching stop layer 32 '... Light-shielding layers 34, 36 ... Positive electron beam resist 34' ... Resist pattern 35 ... Electron beam drawing 37 ... Electron beam overlay drawing 43・ ・ ・ Light transmission part p1 ・ ・ ・ Transmission light of light transmission part p2 ・ ・ ・ Transmission light of phase shift part a ・ ・ ・ Etching depth of phase shift part b ・ ・ ・ Depth before correction of concave shifter defect Depth b '... depth after correction of concave shifter defect

Claims (4)

[Claims] 1. A light transmitting portion or a phase shift portion,
In the case of correcting a shifter defect having a convex shape and having a phase shift property, (a) at least by applying a negative photoresist on the pattern surface side of the substrate and then exposing from the opposite surface side of the substrate, A step of forming a resist pattern by exposing the edge portion of the shifter defect in a self-aligned light-shielding manner and then developing the resist pattern. (B) After that, the convex shifter in the opening of the resist pattern is formed. A step of removing the defect by etching until it reaches a depth almost equal to the original phase plane of the light transmission part or the phase shift part in which the shifter defect exists, and then removing the resist pattern; A method for correcting a shifter defect of a phase shift mask, comprising: and (b). 2. A light transmitting portion or a phase shift portion,
In the case of correcting a shifter defect having a concave shape and having a phase shift property, (c) at least by applying a negative photoresist on the pattern surface side of the substrate and then exposing from the opposite surface side of the substrate, A step of forming a resist pattern by developing the resist pattern by light-shielding the edge portion of the shifter defect in a self-aligned manner and then developing it. (D) After that, the concave shifter defect in the opening of the resist pattern is removed. A step of removing the resist pattern after etching by deeper etching to a depth approximately equivalent to the original amount of phase shift of the phase shift portion, and the above steps (c) and (d) are provided. A method for correcting shifter defects in a phase shift mask. 3. A light transmitting portion or a phase shift portion,
When correcting a shifter defect that is a shifter defect having a phase shift property and has both a convex shape and a concave shape in the same phase shift mask, (e) substrate pattern After applying the negative type photoresist on the surface side, by exposing from the opposite surface side of the substrate, at least the edge portion of the shifter defect of both shapes is shielded from light in a self-aligned manner to be unexposed, and then developed. The step of forming a resist pattern, and after that, the shifter defect of both shapes in the opening of the resist pattern is replaced with a light-transmitting portion or a phase shift where the convex shifter defect is present. Of removing the resist pattern by etching until it reaches a depth almost equal to the original phase surface of the portion, the above (e) and Shifter defect correction method of the phase shift mask, characterized by comprising f). 4. A light transmitting portion or a phase shift portion,
When correcting a shifter defect that is a shifter defect having a phase shift property and has both a convex shape and a concave shape in the same phase shift mask, the pattern of the (g) substrate After applying the negative type photoresist on the surface side, by exposing from the opposite surface side of the substrate, at least the edge portion of the shifter defect of both shapes is shielded from light in a self-aligned manner to be unexposed, and then developed. Step (h) of forming the resist pattern, and thereafter, the shifter defects of both the shapes in the opening of the resist pattern are formed into a concave shape having a depth corresponding to the phase shift amount of the original phase shift portion. After removing the shifter defect by etching until the shifter defect becomes deeper, the resist pattern is removed.
A shifter defect repair method for a phase shift mask, comprising: