KR20100004886A - Multilevel gradation photomask and method for repairing same - Google Patents

Abstract

PURPOSE: A multilevel gradation photomask and a method for correcting defectives are provided to prevent the formation of the generation of transmittance abnormality by controlling the transmittance of a thick film part causing defective resist patterns. CONSTITUTION: A method for correcting a multilevel gradation photomask in which a light-transmitting part and a semi light-transmitting part are installed on a transparent substrate comprises the steps of: exposing some region of a transparent substrate by removing a region containing internal defects of the semi transparent substrate; forming a semi transparent film(4) at the exposed region and laser zapping the first region in a first condition of relatively high energy density; and laser zapping the second region in a second condition of relatively high energy density.

Description

Multi-gradation photomask and its correction method {MULTILEVEL GRADATION PHOTOMASK AND METHOD FOR REPAIRING SAME}

The present invention relates to a multi-gradation photomask and a method of modifying the same.

The "multi-gradation photomask" is an optical mask composed of a translucent portion, a light shielding portion, and a transparent portion exposed by the transparent substrate. The semi-transmissive portion transmits light in accordance with the transmittance. The light shielding portion does not transmit light at all by the light shielding film. The light transmitting part transmits all the light.

If a defect such as an abnormal pattern or a pattern defect is found in the semi-transmissive portion in the multi-gradation optical mask inspection step, "correction of the defect" is performed. The defect correction process generally consists of the following steps. Initially, the region containing the internal defect of the translucent portion is partially removed to expose the region of a part of the transparent substrate. Next, a "translucent film for crystals" is formed in some exposed areas. Finally, the unnecessary quartz semitransmissive film is removed.

In this specification, the semi-transmissive film formed in the formation process of a photomask is called "initial translucent film", and the semi-transmissive film formed after removing a part of the initial translucent film in order to correct a defect is called "modified semi-transmissive film" Distinguish between the two according to need.

16 (a) to 16 (b) and 17 (c) to (d) are schematic diagrams illustrating a modification process of a conventional multi-gradation photomask. Fig. 16A shows a part of the pattern of the conventional multi-gradation photomask 100. Figs. As shown in this figure, the multi-gradation photomask 100 is composed of a light transmitting portion 101, a pattern 102a of a light shielding film, and a pattern 103a (initial semi-transmissive film) of a semi-transmissive film. "D" in FIG. 16A shows the "defect" formed in the pattern 103a of the initial semi-transmissive film of the multi-gradation photomask 100.

FIG. 16B is an enlarged view of a pattern of a multi-gradation photomask showing a state in which a part of a semi-transmissive portion including a defect D is removed. That is, in order to remove the defect D, the correction region R1 (inside the broken line portion in the figure) containing the defect D is partially removed from the state of FIG. 16A (FIG. 16B). This step removes defect D and exposes a part of the transparent substrate.

Next, the quartz semitransmissive film 104 is formed to include the removed portion (Fig. 17 (c)). Further, laser light is irradiated to remove unnecessary portions of the quartz semitransmissive film 104 (Fig. 17 (d)). By this step, the pattern 104a of the quartz semitransmissive film is formed. Thus, the method of selectively removing a quartz semitransmissive film by irradiating a laser beam is called "laser zapping method."

Fig. 17 (d) shows a state in which the formation of the pattern 104a of the quartz semitransmissive film is completed. The defect D in the semi-transmissive portion is completely removed, and the entire region including the defect D is covered with the quartz semi-transmissive film 104.

By the way, with the refinement | miniaturization of the pattern, the uniformity of the transmittance | permeability in the semi-transmissive part is becoming more important recently. This is because a slight difference in transmittance directly affects the thickness of the resist film after transfer as compared with the conventional photomask consisting of only the light shielding portion and the light transmitting portion in the case of a multi-gradation photomask.

For this reason, conventionally, "adjusting the transmittance | permeability with respect to exposure light between an initial semi-transmissive film and a crystal semi-transmissive film" was the biggest important subject (for example, refer patent document 1, 2). That is, if only the transmittance can be adjusted and corrected, it is thought that no other problem will occur in particular.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2008-058943

[Patent Document 2] Japanese Patent Application Laid-Open No. 2007-233350

 However, in some multi-gradation photomasks, there is a phenomenon in which a defective resist pattern that causes short circuits, such as a short circuit, occurs regardless of whether the transmittances of the initial semi-transmissive film and the crystal semi-transmissive film are correctly corrected. Confirmed.

In order to investigate this problem in detail, the cross-sectional structure of the modified multi-gradation photomask (refer to FIG. 17 (d)) obtained by the conventional correction method (FIGS. 16 and 17) was analyzed.

Fig. 15 (a) is a cross-sectional view taken along line X1-X1 of a modified multi-gradation photomask (see Fig. 17 (d)) obtained by a conventional correction method, and Fig. 15 (b) is a multi-gradation photomask of Fig. 15 (a). It is sectional drawing of the resist pattern 111a obtained after an exposure and image development process using the following. As shown in Fig. 15 (a), it can be seen that the film thickness of the quartz semitransmissive film at the pattern edge portion is thicker than the surroundings.

It is not clear that such an abnormal part of the film thickness is formed on the pattern edge of the quartz semitransmissive film. However, the present inventors speculate that the edge part of the quartz semitransmissive film is heated and peeled off by the energy of the laser light to be lifted up when the quartz semitransmissive film is removed by laser zapping. Traces by such laser zapping are referred to herein as "laser zapping marks" for convenience. That is, Figs. 15A and 17C and 15D show that the laser zapping marks 105 are formed in accordance with the trajectory of laser zapping.

Fig. 15B shows a resist pattern obtained by performing exposure and development using the multi-gradation photomask of Fig. 15A. In the example of the resist pattern of FIG. 15B, the resist film thickness is the thickest in the portion corresponding to the pattern 102a of the light shielding film having the lowest transmittance, and the film thickness is the portion corresponding to the pattern 104a of the quartz semitransmissive film. In the portion corresponding to the light-transmitting portion 101 which is thinner than the light-shielding film and has the highest transmittance, all of the resist is removed. By the way, it turns out that the film thickness is locally formed in the resist pattern edge part 114b corresponding to the pattern edge part of a quartz semitransmissive film. This portion, i.e., the resist pattern edge portion 114b, becomes a "deviation part of transmittance" in which the transmittance is smaller than the surrounding transmittance. Therefore, this pattern is determined to be a bad resist pattern. In addition, even if a laser zapping mark is formed on a light shielding film, it does not affect the shape of a resist pattern. In other words, the influence of the laser zapping marks can be considered to be the case where the local thick film portion called the laser zapping marks is formed in the boundary region between the light transmitting portion and the semi-transmissive portion.

This invention is made | formed based on this knowledge, and makes it a technical subject to avoid the generation | occurrence | production of the abnormal part of the transmittance which may arise at the time of formation of a quartz semitransmissive film in the correction process of a multi-gradation photomask.

 The multi-gradation photomask according to the present invention is a multi-gradation photomask of a defect fixer, wherein a light transmitting portion, a light blocking portion, and a semi-transmissive portion are provided on a transparent substrate, and the semi-transmissive portion is formed by a pattern of a semi-transmissive film. The light-transmitting film includes a thick film portion formed by laser zapping, and a transmittance adjusting region is provided in the thick film portion.

This transmittance adjusting area includes all means provided to make the transmittance of the thick film portion formed in the laser zapping step in the defect correction step equal to the transmittance of the surroundings.

According to the multi-gradation photomask and defect correction method according to the present invention, since the transmittance of the thick film portion which causes the defective resist pattern is adjusted, formation of an abnormal portion of the transmittance can be prevented.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment is described. In each figure, the same code | symbol is used when showing the same site | part.

[First embodiment]

1 (a)-(b) and 2 (c)-(d) are modification process diagrams of the multi-gradation photomask according to the embodiment of the present invention. FIG. 1A shows a part of the pattern of the multi-gradation photomask 10 according to the embodiment of the present invention. The multi-gradation photomask 10 is composed of the light transmitting portion 1, the pattern 2a of the light shielding film, and the pattern 3a of the initial semi-transmissive film. Here, the defect D exists in the pattern 3a of the initial semi-transmissive film of the multi-gradation photomask 10.

In addition, this defect D is in contrast to a defect in which a translucent film is not formed in a portion where a translucent film is to be originally formed or a film thickness is locally thinned (this is called a "white defect"). Although it is largely classified as a locally thickening defect (this is called a "black defect"), the correction method according to the present invention removes the region containing the defect and forms a new film, so the type of defect is not asked. Do not.

FIG.1 (b) is an enlarged view of the pattern of the multi-gradation photomask which shows the state (part of initial translucent film) which removed the semi-transmissive part containing defect D. FIG. That is, in order to remove the defect D, the correction region R2 (inside the broken line in the figure) containing the defect D is partially removed from the state of FIG. 1 (a) (FIG. 1 (b)). This step removes defect D and exposes a part of the transparent substrate.

Next, although the quartz semitransmissive film 4 is formed to include the removed portion, the method of forming the quartz semitransmissive film according to the present invention will be described with reference to FIG.

Fig. 3 (a) shows a state in which the irradiation range is sequentially moved while irradiating laser light of energy densities I ₁ and I ₂ [J / cm 2] having different sizes onto the quartz semitransmissive film. 3 (b) and 3 (c) are cross-sectional views taken along lines X2-X2 and Y1-Y1 of FIG. 3 (a), respectively.

In addition, as shown in Fig. 3 (a), the laser light irradiation area is usually spherical, and the laser light is sequentially moved while pulsed irradiating the laser light, but is not limited to this method.

In the laser zapping process of the quartz semi-transmissive film according to the embodiment of the present invention, laser zapping is performed at an energy density smaller than the energy density that has been used as conventional laser light for at least an important region that may cause a pattern abnormality. We carry out. That is, if a conventional irradiation energy of the laser to jaeping I ₀ [J / ㎠], is represented as shown in equation (3).

I ₀ ≥ I ₁ > I _{2 ...} (3)

The results of Figs. 3A to 3C show that laser zapping at a relatively small energy density can reduce the size of the laser zapping marks than before.

That is, in the conventional laser zapping, as shown in Fig. 17 (d) and Fig. 15 (a), the large laser zapping marks 105 were formed in accordance with the trajectory of laser zapping, but the modified half according to the first embodiment In the process of forming the light-transmitting film, since the laser light is irradiated at an energy density equal to or lower than that in the prior art, even if the large laser zapping trace 105 is not formed or is formed, a large enough to cause the abnormal pattern is not formed. In other words, the problem is solved by performing laser zapping at a relatively low energy density so that at least a portion where the pattern abnormality is a problem does not form a large laser zapping mark that causes the resist pattern abnormality.

Based on the principle described above, laser zapping of the quartz semitransmissive film is performed at a relatively small energy density.

As shown in Fig. 2 (c), the crystal semitransmissive film 4 is formed on the pattern 2a of the light shielding film, and lower energy density I ₁ [J / cm 2] and I ₂ [J / cm 2] ( However, by irradiating the laser light of I ₁ > I ₂ , the unnecessary portion of the quartz semitransmissive film 4 is removed to form the pattern 4a of the quartz semitransmissive film (FIG. 2 (d)).

As the method for forming the quartz semitransmissive film 4, a vapor phase growth method, in particular, a chemical vapor growth method or a physical vapor growth method is preferable. In the case of the chemical vapor growth method, a method capable of locally depositing on a specific region, such as a photoCVD method, is preferable. In the optical CVD apparatus, compared with other film forming apparatuses, it is easy to change conditions such as the number of times of irradiation of light (pulse frequency), the intensity of irradiation of light, and the like.

Fig. 2 (d) shows a state in which the formation of the pattern 4a of the quartz semitransmissive film is completed. As shown in this figure, the defect D in the translucent portion is completely removed.

In summary, the conditions of laser zapping according to the embodiment of the present invention are shown in Table 1 below.

However, the region I refers to a region in which the quartz semitransmissive film is not isolated and the formation of an abnormal pattern is not a serious problem. The region II is a quartz half isolated on the light transmitting portion such as the source electrode and the drain electrode forming portion of the thin film transistor. It indicates an area where a problem may occur when an abnormal pattern such as an edge portion of the pattern of the light transmitting film is formed (see FIG. 2 (d)).

That is, in the example of FIG. 2C, the energy density is switched to two different sizes I ₁ and I ₂ because the size of the laser zapping marks allowed by the pattern state is different. For example, even if a laser zapping mark is formed at the boundary between the translucent portion and the light blocking portion, since the exposure light is literally blocked at the light blocking portion, even if a thick film portion formed by the laser zapping mark is formed in the vicinity thereof, the influence on the exposure pattern is extremely small. small. On the other hand, when the laser zapping is performed by substituting the semi-transmissive film pattern formed on the light-transmitting part with a modified semi-transmissive film, if the local thick film part is formed by the laser zapping marks, it may be considered to have a serious effect on the exposure pattern. have.

For this reason, in FIG. 2 (c), a pattern that needs to be modified to perform laser zapping at an even weaker energy density in an important part (low energy laser irradiation unit K) where a short may occur in a wiring forming process, etc., which is performed after pattern formation in the future. In consideration of switching between two types of energy densities, laser zapping may be performed at the same energy density (but irradiating with a relatively lower energy density than before) if not necessary.

Fig. 4A is an enlarged cross-sectional view taken along line X3-X3 in Fig. 2D. On the light-transmitting part 1 exposed by the glass substrate, the pattern 2a of the light shielding film and the pattern 4a of the quartz semi-transmissive film are formed, and the low-energy laser irradiation part K is formed in a part of the boundary region with the light-transmitting part 1. What is formed is shown. Moreover, as shown in this figure, exposure light is irradiated from the back surface side of a glass substrate.

FIG. 4B is a cross-sectional view of the resist pattern after exposure and development using the multi-gradation photomask of FIG. 4A. In the example of the resist pattern of FIG. 4 (b), the resist film thickness is the thickest at the portion corresponding to the pattern 2a of the light shielding film having the lowest transmittance, and the film thickness is the light shielding film at the portion corresponding to the pattern 4a of the quartz semitransmissive film. In the portion corresponding to the light-transmitting portion 1, which is thinner and has the highest transmittance, all the resist is removed, but in the resist pattern edge portion 14b corresponding to the low-energy laser irradiation portion formed on the pattern edge portion of the translucent film, The film thickness is smoothly decreasing.

As described above, in the method for correcting the multi-gradation photomask according to the embodiment of the present invention, the low-energy laser irradiating portion is provided at the portion close to the boundary with the light transmitting portion in the process of forming the quartz semi-transmissive film so that the "transmittance of transmittance" The abnormal part cf FIG. 15 (b) 114b) can be avoided.

Second Embodiment

5 (a)-(b) and 6 (c)-(d) are defect correction process diagrams of the multi-gradation photomask according to the second embodiment. 5 (a) and 5 (b) show a part of the pattern of the multi-gradation photomask 10 according to the second embodiment, but the description is omitted because it is the same as that of FIGS. 1 (a) and (b).

Next, as shown in Fig. 6C, the crystal semitransmissive film 4 is formed on the pattern 2a of the light shielding film, and irradiated with laser light to remove unnecessary portions of the quartz semitransmissive film 4. This forms the pattern 4a of the quartz semitransmissive film (FIG. 2 (c)). In addition, as shown in the drawing, the irradiation area of the laser light is usually spherical, and it is common to move sequentially while the laser light is pulsed, but the method is not limited to this.

When this process is complete | finished, the laser zapping trace 5 is formed in the site | part where laser zapping was performed among the quartz semitransmissive films (FIG. 6 (d)).

Fig. 7E shows the formation of the pattern 4a of the quartz semitransmissive film. As shown in this figure, one or more slits are applied to a part of the laser zapping marks 5 by specifying a location where an abnormal pattern is formed among the laser zapping marks 5 and irradiating minute laser light L to the portions thereof. The slit part S which consists of 6) is formed. This slit part S is provided only in the required location.

8 shows an enlarged view of the slit part S. FIG. The laser zapping marks 5 are thickened locally, and have a property close to that of the light shielding film in that the transmittance is locally lowered compared to the surroundings. On the other hand, the slit part S has the space | interval below the resolution limit which an exposure light can pass, and has a function which locally raises the transmittance | permeability of the laser zapping trace 5. The slit part S is provided in the laser zapping trace 5, and therefore formation of an abnormal pattern is suppressed.

In addition, the slit portion S generates a laser zapping trace 5, for example, an end portion of an isolated pattern portion, such as a pattern of semi-transmissive layers isolated on a transparent substrate, such as a source electrode and a drain electrode of a thin film transistor. If the lower surface transmittance is preferably provided locally. This is because the abnormal pattern is easily generated by the laser zapping marks 5 in the isolated pattern portion. On the contrary, even if the laser zapping traces are formed on the light shielding film or in the vicinity of the light shielding film, the formation of the abnormal pattern is less likely to occur than in the case where the laser zapping traces 5 are formed in the isolated pattern portion. The judgment of is determined by whether or not an abnormal pattern is formed.

In addition, when a part of a transparent substrate is exposed in order to remove the defect D, and a quartz semitransmissive film is deposited, it is preferable to deposit in the area slightly larger than the area | region of an initial semitransmissive film, ie, overlapping an exposed part. This is because it is easy to secure redundancy.

(A) is an expanded sectional view of the X2-X2 line shown to FIG. 7 (e). A pattern 2a of a light shielding film and a pattern 4a of a quartz semi-transmissive film are formed on the transparent part 1 exposed by the transparent substrate, and a slit part S is formed in at least a portion of the boundary region with the light transmitting part 1. It is shown. Moreover, as shown in this figure, exposure light is irradiated from the back surface side of a transparent substrate.

Fig. 9B shows a resist pattern obtained by performing exposure and development using such a multi-gradation photomask. In the example of the resist pattern of Fig. 9B, the resist film thickness is the thickest at the portion corresponding to the pattern 2a of the light shielding film having the lowest transmittance, and the film thickness is the light shielding film at the portion corresponding to the pattern 4a of the quartz semitransmissive film. In the portion corresponding to the light-transmitting portion 1, which is thinner and has the highest transmittance, all of the resist is removed, but the resist pattern edge portion corresponding to the slit portion S formed in the pattern edge portion of the quartz semitransmissive film ( In 14b), the film thickness is changed into a stepped or tapered shape.

As described above, in the method for correcting the multi-gradation photomask according to the embodiment of the present invention, the slit portion S is provided at the end of the quartz semitransmissive film in the step of forming the quartz semitransmissive film. In S), the transmittance rises locally. That is, the photoresist film after pattern transfer is formed thin in the vicinity of the boundary with the light transmitting portion, and the change in transmittance from the semi-transmissive portion to the light transmitting portion is moderate. For this reason, it becomes possible to avoid the transmittance | permeability abnormality which arises at the time of formation of the crystal semitransmissive film which occurred in the periphery of the effective area | region of a crystal semitransmissive film, and abnormality of the resist film thickness at the time of transfer exposure (transmittance " Abnormality (what FIG. 16 (b) 114b) is formed in) can be avoided.

Moreover, it is preferable that the slit width is adjusted so that the transmittance | permeability of the slit part S and its periphery may be made as possible regarding the wavelength of exposure light.

[Third Embodiment]

FIG.10 (a)-(b) and FIG.11 (c)-(d) are the defect correction process drawing of the multi-gradation photomask which concerns on 3rd Embodiment. 10 (a) and 10 (b) show a part of the pattern of the multi-gradation photomask 10 according to the third embodiment, but the description is omitted because it is the same as that in FIGS. 1 (a) and 1 (b).

Next, although the crystal semitransmissive film 4 is formed so that the removed part may be included, the formation method of the crystal semitransmissive film concerning this invention is demonstrated with reference to FIG.

12 (a) to 12 (c) are schematic diagrams illustrating a step of forming a quartz semitransmissive film 4 according to an embodiment of the present invention, and (a) is a quartz semitransmissive film 4 on a flat glass substrate. (B) and (c) are sectional views of the Y1-Y1 line and the X2-X2 line of (a), respectively.

As shown in this figure, when the quartz semitransmissive film 4 is formed, it is first deposited in the widest range, and then is deposited in a slightly narrow range with almost coincident centers, and the deposition range is changed stepwise. It is deposited. It is relatively easy to narrow the deposition range gradually when using the optical CVD apparatus at the time of performing the vapor phase growth method.

In this way, as shown in Figs. 12A to 12C, the gradation part G is formed in the entire peripheral part of the quartz semitransmissive film. In the gradation portion G, the closer to the boundary with the light transmitting portion, the higher the transmittance. Although the roughness of the steps varies depending on the number of scans during film formation, the gradation part G does not necessarily have to be a smooth tapered shape, and may be a relatively rough step shape. On the other hand, in the center part C formed inside the gradation part G, conditions, such as film thickness, are adjusted so that the transmittance | permeability with respect to the wavelength of the exposure light of an exposure apparatus may be equal to an initial semi-transmissive film.

In the gradation portion G, since the transmittance changes stepwise, the photoresist film after pattern transfer becomes thinner as the resist film thickness approaches the boundary with the transmissive portion, and the change in transmittance from the translucent portion to the transmissive portion is gentle. For this reason, it becomes possible to avoid the transmittance | permeability abnormality which arises at the time of formation of the quartz semitransmissive film which generate | occur | produced in the effective area periphery of a crystal semitransmissive film, and can avoid the abnormality of the resist film thickness at the time of transfer exposure. have.

As shown in Fig. 11 (c), the crystal semitransmissive film 4 is formed on the pattern 2a of the light shielding film by forming a quartz semitransmissive film 4 having a gradation portion G and irradiating laser light. By removing the unnecessary portion of (), the pattern 4a of the quartz semitransmissive film is formed (Fig. 11 (d)).

In addition, although the laser zapping mark 5 is formed in the site | part where laser zapping was performed to the quartz semitransmissive film, the laser zapping mark 5 is not formed in the site | part which left the gradation part G without performing laser zapping.

In order to remove the defect D, after exposing a part of the transparent substrate and depositing the quartz semitransmissive film, it may be deposited in an area slightly wider than that of the initial semitransmissive film, that is, the exposed part. This is because the redundancy is easy to be secured and the area of the gradation part G is easily secured.

Fig. 11 (d) shows a state in which the formation of the pattern 4a of the quartz semitransmissive film is completed. As shown in this figure, the defect D in the translucent portion is completely removed. As mentioned above, although the gradation part G is formed in the whole periphery immediately after the film formation of the quartz semi-transmissive film 4, an unnecessary part is laser-wapped by a laser beam as needed. 11 (d) shows that the gradation portion G is left in part of the pattern 4a of the quartz semitransmissive film. However, the laser zapping process may be omitted after defining a sufficient film forming range without forming a redundant region at the time of forming the quartz semitransmissive film 4.

(A) is an expanded sectional view of the X3-X3 line shown to FIG. 11 (d). A pattern 2a of the light shielding film and a pattern 4a of the quartz semitransmissive film are formed on the light transmitting part 1 exposed by the glass substrate, and a gradation part G is formed on at least a part of the boundary region with the light transmitting part 1. It is shown. Moreover, exposure light is irradiated from the back surface side of a glass substrate as shown in this figure.

FIG. 13B is a cross-sectional view of the resist pattern after exposure and development using the multi-gradation photomask shown in FIG. 13A. In the example of the resist pattern of FIG. 13 (b), the resist film thickness is the thickest at the portion corresponding to the pattern 2a of the light shielding film having the lowest transmittance, and the film thickness is the portion corresponding to the pattern 4a of the quartz semitransmissive film. In the portion corresponding to the light-transmitting portion 1 that is thinner than the light-shielding film and has the highest transmittance, all the resist thickness is removed, but the resist pattern edge portion corresponding to the gradation portion G formed on the pattern edge portion of the translucent film ( In 14b), the film thickness is changed into a stepped or tapered shape.

As described above, in the method of modifying the multi-gradation photomask according to the embodiment of the present invention, in the step of forming the quartz semitransmissive film, the resist pattern is provided by providing a gradation portion configured to have a higher transmittance near the boundary with the light transmitting portion. It can be avoided that "the abnormal part of a transmittance | permeability (FIG. 15 (b) 114b)" is formed in an edge part.

Moreover, it is preferable that the quartz semitransmissive film is adjusted substantially the same as the transmittance of the initial semitransmissive film in other regions except for the gradation part.

In this way, the transmittance of both is adjusted to the same degree, and the gradation portion is provided at the pattern edge portion, whereby the transmittance of the semi-transmissive portion becomes almost uniform at portions other than the pattern edge portion, and formation of an abnormal portion of the transmittance can be prevented.

In this case, it is preferable that the film thickness of the semi-transmissive film in the gradation portion is configured to be thin enough to face the end. One of the most effective methods for adjusting the transmittance is a method for adjusting the film thickness. In addition, although the relationship between a film thickness and a transmittance | permeability is represented by Formula (1) and Formula (2), qualitatively, the thinner the film thickness, the higher the transmittance, and the thicker the film, the lower the transmittance.

When the concentration of the transmittance of the unit when the thickness L ₀ T _0, the transmittance T ₀ when the concentration of D _0, L as a thickness D that is shown, as follows:

D ₀ = -log T ₀ (1)

D = (L / L ₀ ) · D _{0 ...} (2)

If necessary, the method may further include a step of selectively removing a part of the quartz semitransmissive film by a method such as laser zapping. This is because the thickness of the pattern edge portion becomes thicker when the quartz semitransmissive film is removed by laser zapping or the like. However, the provision of the gradation portion avoids the occurrence of a defective resist pattern. In this sense, it is because it does not interfere with the process which selectively removes a part of quartz semitransmissive film in the range in which a bad resist pattern is not formed.

The end of the quartz semitransmissive film is preferably an edge portion of the pattern of the crystal semitransmissive film isolated on the source and drain electrode formation regions of the thin film transistor having a source and a drain, and the other transmissive portion.

INDUSTRIAL APPLICABILITY The present invention is extremely applicable to the manufacture of a multi-gradation photomask, particularly in that it can provide a technique for improving the accuracy of correcting defects.

Fig.1 (a)-(b) is a defect correction process diagram of the multi-gradation photomask which concerns on 1st Embodiment.

2C to 2D are defect correction process diagrams of a multi-gradation photomask according to the first embodiment.

FIG. 3 (a) is a diagram showing a state in which the irradiation range is sequentially moved while irradiating a laser light of energy densities I ₁ and I ₂ [J / cm 2] having different sizes on a quartz semitransmissive film. (b) and (c) are sectional views of the X2-X2 line and Y1-Y1 line of (a).

Fig. 4A is an enlarged cross-sectional view of the X3-X3 line in Fig. 2D. (b) is sectional drawing of the resist pattern after exposing and developing using the multi-gradation photomask of (a).

5A to 5B are defect correction process diagrams of a multi-gradation photomask according to a second embodiment.

6C to 6D are defect correction process diagrams of a multi-gradation photomask according to the second embodiment.

Fig. 7E is a defect correction process diagram of the multi-gradation photomask according to the second embodiment. Particularly, a process chart showing a state in which the pattern 4a of the quartz semitransmissive film is formed.

8 is an enlarged view of the slit portion S;

(A) is an expanded sectional view of the X2-X2 line of FIG.7 (e). (b) is sectional drawing of the resist pattern after exposing and developing using the multi-gradation optical mask of (a).

10A to 10B are defect correction process diagrams for a multi-gradation photomask according to a third embodiment.

11 (c) to 11 (d) are defect correction process diagrams of a multi-gradation photomask according to a third embodiment.

FIG. 12A is a plan view showing a state in which the quartz semitransmissive film 4 is formed on a flat glass substrate. FIG. (b) and (c) are sectional views of the Y1-Y1 line and the X2-X2 line of (a), respectively.

(A) is an expanded sectional view of the X3-X3 line | wire of FIG. 11 (d). (b) is sectional drawing of the resist pattern after exposing and developing using the multi-gradation photomask of (a).

(A) is an expanded sectional view of the X3-X3 line | wire of FIG. 11 (d). (b) is sectional drawing of the resist pattern after exposing and developing using the multi-gradation photomask of (a).

FIG. 15A is a cross-sectional view taken along line X1-X1 of a modified multi-gradation photomask (see FIG. 17 (d)) obtained by a conventional correction method (FIGS. 16 and 17). (b) is sectional drawing of the resist pattern 111a obtained after an exposure and image development process using the multi-gradation photomask of (a).

16A to 16B are diagrams showing modification steps of a conventional multi-gradation photomask.

17C to 17D are diagrams showing modification steps of a conventional multi-gradation photomask.

[Description of the code]

1, 101: floodlight

2a, 102a: pattern of light shielding film

3a, 103a: pattern of the initial translucent film

4, 104: quartz translucent film

4a, 104a: Pattern of Crystal Translucent Film

5, 105: laser zapping marks

11a and 111a: resist pattern

14b: Stepped to Tapered Resist Pattern Edge (Modification Pattern)

114b: Resist pattern edge portion (abnormal pattern)

R1, R2: modification area

Claims (23)

A light transmitting portion, a light blocking portion, and a semi-transmissive portion are provided on the transparent substrate, the semi-transmissive portion is formed by a pattern of a semi-transmissive layer, and the semi-transmissive layer includes a thick film portion formed by laser zapping. And a transmittance adjusting region is provided in the thick film portion. A light transmitting portion, a light blocking portion, and a semi-transmissive portion are provided on the transparent substrate, and the semi-transmissive portion is formed by a pattern of the semi-transmissive layer, and the semi-transmissive layer is subjected to laser zapping under at least two or more conditions having relatively different energy densities. Multi-gradation photomask with irradiation part. The method of claim 2, The low energy irradiator is a multi-gradation optical mask, characterized in that the edge (edge) of the crystal semi-transmissive film pattern isolated on the light transmitting portion. The method according to claim 2 or 3, The semi-transmissive film is a multi-gradation photomask, characterized in that the film formed by the vapor phase growth method. A method of correcting a multi-gradation photomask provided with a light transmitting portion, a light blocking portion, and a semi-transmissive portion on a transparent substrate, the method comprising exposing a portion of the transparent substrate by removing a region including internal defects of the semi-transmissive portion; In order to form a semi-transmissive film for correction in some areas and to remove unnecessary semi-transmissive films, laser zapping under a first condition having a relatively high energy density with respect to the first area, and a second step. A method of modifying a multi-gradation photomask comprising laser zapping under a second condition having a relatively low energy density for a region of. The method of claim 5, And the second region is an edge portion of a pattern of a crystal semitransmissive film isolated on the source and drain electrode forming regions of the thin film transistor having a source and a drain and other light transmitting portions. A light transmitting portion, a light blocking portion, and a semi-transmissive portion are provided on the transparent substrate, wherein the semi-transmissive portion is formed by a pattern of a semi-transmissive membrane, and the semi-transmissive membrane has a slit portion at least part of a boundary region with the light-transmitting portion. Multi-gradation photomask. The method of claim 7, wherein The semi-transmissive portion includes a first semi-transmissive film formed by the first film forming method and a second semi-transmissive film formed by the second film-forming method, and the slit portion includes an end portion of the second semi-transmissive film ( A multi-gradation photomask, which is formed in the back part. The method of claim 7, wherein The second semi-transmissive film is adjusted to be substantially the same as the transmittance of the first semi-transmissive film in other regions except for the slit portion. The method of claim 7, wherein The slit portion has a spacing below the resolution limit of the wavelength of the exposure light when the multi-gradation photomask is exposed. The method according to any one of claims 8 to 10, The second semi-transmissive film is a multi-gradation photomask, characterized in that the film is formed locally to include a region removed after a portion of the first translucent film is removed. The method according to any one of claims 8 to 10, The second semi-transmissive film is a multi-gradation photomask, characterized in that the film formed by the vapor phase growth method. A method of modifying a multi-gradation photomask provided with a light transmitting portion, a light blocking portion, and a semi-transmissive portion on a transparent substrate, the method comprising exposing a portion of the transparent substrate by removing a region containing an internal defect of the semi-transmissive portion; Forming a quartz semitransmissive film to include some regions, and then forming one or a plurality of slits at an end of the quartz semitransmissive film. The method of claim 13, An end portion of the crystal semi-transmissive film having the slit may be an edge portion of the pattern of the crystal semi-transmissive film isolated on the source and drain electrode formation regions of the thin film transistor having a source and a drain, and other light-transmitting portions. How to modify gradation photomask. A light transmitting portion, a light blocking portion, and a semi-transmissive portion are provided on the transparent substrate, and the semi-transmissive portion is formed by a pattern of a semi-transmissive membrane, and the semi-transmissive membrane is at least a part of the boundary area with the light-transmitting portion and borders with the light-transmitting portion. A multi-gradation photomask having a gradation portion configured to have a higher transmittance near to. The method of claim 15, The transflective film in the said transflective part contains a 1st transflective film, and the 2nd transflective film formed by the film-forming method different from the said 1st translucent film, The said 2nd translucent film is the said, The multi-gradation optical mask is adjusted to be substantially the same as the transmittance of the first semi-transmissive film in other regions except for the gradation portion. The method according to claim 15 or 16, The film thickness of the said translucent film in the said gradation part is thinner toward the edge part, The multi-gradation optical mask characterized by the above-mentioned. The method of claim 16, And the second semi-transmissive film is a film formed locally to include the removed region after a portion of the first semi-transmissive film is removed. The method according to any one of claims 16 to 18, The second semi-transmissive film is a multi-gradation photomask, characterized in that the film formed by the vapor phase growth method. The method of claim 19, The gradation unit is a multi-gradation photomask, characterized in that obtained by changing the deposition range of the vapor phase step by step. A method of correcting a multi-gradation optical mask provided with a light transmitting portion, a light blocking portion, and a semi-transmissive portion on a transparent substrate, the method comprising exposing a portion of the transparent substrate by removing an area including an internal defect of the semi-transmissive portion; A method of correcting a multi-gradation photomask, comprising: forming a quartz semitransmissive film to include a portion of the region, and then moving the edge of the quartz semitransmissive film little by little. The method of claim 21, And removing the part of the quartz semitransmissive film selectively. The method of claim 21 or 22, The end of the quartz semitransmissive film is a source electrode and a drain electrode forming region of the thin film transistor having a source and a drain, and the edge portion of the pattern of the crystal semitransmissive film isolated on the light transmitting part. .

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