JP2005107340A - Photomask plate and its making method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photomask plate having a pattern on which a foreign matter hardly remains on the photomask plate after cleaning the plate, and the photomask plate having improved pattern accuracy, and to provide a method for making a photomask plate by which the above photomask plate can be reliably made by a simple method, repeated cleaning steps for eliminating a foreign matter after cleaning can be reduced, and the cost can be reduced. <P>SOLUTION: In the photomask plate 1 having a mask pattern 6 of a desired figure consisting of a light shielding film 5 on a transparent substrate, a recessed portion 4 giving the figure of the mask pattern 6 is formed on the surface of the transparent substrate 2, and the light shielding film 5 is formed in the recessed portion 4 but not protruding from the surface of the transparent substrate 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a photomask plate used in photolithography technology and a method for producing the same.

  Conventionally, a photomask plate 1 and a photolithographic technique using the photomask plate 1 have a feature that a large amount of fine wiring can be formed in one process. In the field of manufacturing printed circuit boards, semiconductors, etc.

  FIG. 3 is an explanatory view showing a conventional photomask plate 1 (see FIG. 3g) and a process for producing the photomask plate 1. As shown in FIG.

  As shown in this figure, the conventional photomask plate 1 is formed through the following basic process and cleaning performed as needed during the basic process.

  First, the surface of the transparent substrate 2 such as glass is polished (FIG. 3a), and a light shielding film 5 serving as a mask is formed on the polished surface (FIG. 3b). Next, a resist 3 (photosensitive agent) is applied to the surface of the light-shielding film 5 (FIG. 3c), and the resist 3 is irradiated with photosensitive wavelength light (ultraviolet rays) to expose and transfer the mask pattern ( FIG. 3d). Subsequently, the exposed resist 3 is developed and washed with washing water (FIG. 3e).

  At this time, in the photolithography technique, development is performed so as to remove a portion exposed by exposure, and a method using a positive resist in which a portion not exposed is used as a mask pattern 6, conversely, a portion exposed by exposure is exposed. There is a method of using a negative resist that is developed so as to leave the mask pattern 6 and removes the unexposed portion. Although any method can produce the photomask plate 1 having a desired pattern, in the conventional example shown in FIG. 3, the photomask plate 1 is formed by photolithography using the positive resist. Indicates the case of creation.

  Subsequently, the portion of the light shielding film 5 not covered with the resist 3 is removed by etching (FIG. 3F). As this etching method, a wet etching method in which the substrate is immersed in an etching solution, a dry etching method in which the substrate is placed in an etching gas atmosphere, and etching is performed using ions or the like can be employed.

  Finally, the resist 3 covering the light-shielding film 5 is peeled and removed using sodium hydroxide to produce a photomask plate 1 (FIG. 3g).

  The photomask plate 1 produced through such basic steps has a light shielding film 5 formed in a convex shape on the surface of the transparent substrate 2 as shown in FIG. 3g. Therefore, as shown in FIG. 4, even if it is said that cleaning is carried out as needed after use of the photomask plate 1, the light shielding portion where the convex light shielding film 5 is formed and the light shielding film 5 are formed. The foreign matter 7 that should be removed is likely to remain in the partition that is the boundary of the transmission portion that is not.

  For this reason, after the cleaning of the photomask plate 1 described above, an inspection process for inspecting the presence or absence of the remaining foreign matter 7 is added, and when the residual foreign matter 7 is detected, it is essential to perform cleaning again. It was.

  Further, as shown in FIG. 4, the photomask plate 1 with the foreign matter 7 attached to the partition portion remains on the region where the foreign matter 7 functions as a transmission portion of the photomask plate 1, so Since it acts in the same manner as the formed mask pattern 6, the object to be transferred using the photomask plate 1, for example, the transparent substrate 2 on which the electrode pattern of the liquid crystal display panel is formed is the target. There has been a problem of patterning failure that the pattern cannot be transferred. As described above, unless a target pattern is obtained as an object to be subjected to pattern transfer, the function and operation of the member having the pattern to be formed are hindered. For example, in the case of the liquid crystal display panel described above, there is a concern that when the display electrode pattern is short-circuited or disconnected, it may appear as a defect such as a display defect of the liquid crystal display panel.

  In view of this, the present invention provides a photomask plate that has a shape in which foreign matter is unlikely to remain on the washed photomask plate and can improve the patterning accuracy, and the photomask plate is surely produced by a simple method. An object of the present invention is to provide a method for producing a photomask plate that can improve productivity by reducing the inspection process and re-cleaning process after cleaning, and that can also reduce costs It is.

  In order to achieve the above-described object, the photomask plate of the present invention is a photomask photomask plate in which a mask pattern having a desired shape made of a light-shielding film is formed on a transparent substrate, and the mask pattern is formed on the surface of the transparent substrate. A recess having a mask pattern shape is formed, and a light shielding film is formed in the recess so as not to protrude from the surface of the transparent substrate.

  Further, the method for producing a photomask plate of the present invention comprises forming a recess having a desired mask pattern shape on the surface of the transparent substrate, forming a light shielding film on the surface of the transparent substrate on which the recess is formed, Then, the mask pattern is formed by polishing the surface of the transparent substrate so that the light shielding film fits in the recess and does not protrude from the surface of the transparent substrate.

  The photomask plate of the present invention is formed so that the mask pattern does not protrude substantially flush with the surface of the transparent substrate.

  In the photomask plate in which the mask pattern is formed substantially flush with the surface of the transparent substrate, foreign matter is unlikely to remain on the surface of the transparent substrate, and the surface of the light shielding portion of the photomask plate is concave. Therefore, foreign matter may remain in the concave portion, but even in that case, the foreign matter will remain on the mask pattern, that is, on the region functioning as the light-shielding portion of the photomask plate. It does not affect the transmission part of the photomask plate and does not change the shape of the mask pattern.

  As described above, according to the photomask plate of the present invention, there is no change in the shape of the mask pattern due to adhesion of foreign matter between the mask patterns, and the desired mask pattern shape can be reliably obtained. The patterning accuracy used can be improved.

  And, according to the method for producing a photomask plate of the present invention, as described above, the cleaning in the production process is facilitated, and it is not necessary to repeat inspection and rewashing for photomask plate cleaning. The cost of washing water and labor costs can be reduced.

  FIG. 1 is an explanatory view showing a photomask plate 1 of the present invention (see FIG. 1g) and a process for producing the photomask plate 1. FIG.

  As shown in this figure, the photomask plate 1 of the present invention is prepared through the following basic process and cleaning performed as needed during the basic process.

  First, a resist 3 is applied to the surface of the transparent substrate 2 (FIG. 1a). As the transparent substrate, a glass substrate such as a silicate glass (hereinafter referred to as soda glass) containing an alkali metal such as Na (sodium) or a quartz substrate can be used. Next, the resist 3 is irradiated with photosensitive wavelength light (ultraviolet rays) to expose and transfer the mask pattern (FIG. 1b). Then, the exposed resist 3 is developed, washed with washing water (FIG. 1c), and the transparent substrate 2 where the resist 3 is removed is etched to form a desired mask pattern 6 on the surface of the transparent substrate 2. A recess 4 is formed (FIG. 1d). Thereafter, a light shielding film 5 is formed on the upper surface of the resist 3 remaining on the surface of the transparent substrate 2 and the upper surface of the recess 4 (FIG. 1e). Then, the resist 3 and the light shielding film 5 formed on the upper surface of the resist 3 are peeled and removed (FIG. 1f), and the surface of the transparent substrate 2 is accommodated in the concave portion 4 by the light shielding film 5 and A mask pattern 6 is formed by polishing so as not to protrude on the surface of the transparent substrate 2, and a photomask plate 1 is prepared (FIG. 1g).

  The photomask plate 1 of the present embodiment formed in this way is formed so that the mask pattern 6 does not protrude from the surface of the transparent substrate 2, that is, substantially flush with the surface of the transparent substrate 2. The Rukoto. Then, as shown in FIG. 1g, the photomask plate 1 in which the mask pattern 6 is formed substantially flush with the surface of the transparent substrate 2 has no convex portions on the surface thereof. The residue of the foreign matter 7 is extremely difficult to occur. Further, when the light shielding film 5 constituting the mask pattern 6 is disposed so as to be immersed in the recess 4, that is, when the light shielding film 5 is formed lower than the surface of the transparent substrate 2. The surface of the photomask plate 1 is concave. Therefore, as described above, there is a higher possibility that the foreign matter 7 remains in the uneven step portion as compared with the case where the surface of the photomask plate 1 is formed flush. However, in that case, as shown in FIG. 2, the foreign matter 7 remains on the mask pattern 6, that is, in a region functioning as a light-shielding portion of the photomask plate 1. The shape of the mask pattern is not changed.

  As described above, according to the photomask plate 1 of the present invention, there is no change in the shape of the mask pattern 6 due to adhesion of the foreign matter 7 between the mask patterns 6, and the desired shape of the mask pattern 6 can be obtained reliably. Thus, the patterning accuracy using the photomask plate 1 can be improved.

  Further, a concave portion 4 having the shape of a desired mask pattern 6 is formed on the surface of the transparent substrate 2, and a light shielding film 5 is formed on the surface of the transparent substrate 2 on which the concave portion 4 is formed. The mask pattern 6 is formed by polishing the surface of the transparent substrate 2 so that the mask 5 is accommodated in the recess 4 and does not protrude onto the surface of the transparent substrate 2. According to the production method, the photomask plate 1 can be reliably produced by a simple method, and it is not necessary to repeat inspection and re-washing for cleaning the photomask plate 1, thereby improving productivity. It is possible to reduce costs such as washing water and labor costs.

  In addition, this invention is not limited to embodiment mentioned above, A various change is possible as needed. For example, the present invention can be applied to a negative photomask in addition to the positive photomask illustrated above.

Explanatory drawing which shows the process of producing the photomask plate of embodiment of this invention Explanatory drawing which shows the foreign material which remains on the photomask plate of this embodiment Explanatory drawing which shows the process of creating the conventional photomask plate Explanatory drawing showing foreign matter remaining on a conventional photomask plate

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photomask plate 2 Transparent substrate 3 Resist 4 Concave part 5 Light shielding film 6 Mask pattern 7 Foreign material

Claims (2)

  In a photomask plate in which a mask pattern having a desired shape made of a light-shielding film is formed on a transparent substrate, the mask pattern is formed with a recess having a mask pattern shape on the surface of the transparent substrate, and the recess is formed in the recess. A photomask plate, wherein a light shielding film is formed so as not to protrude from the surface of the transparent substrate. Forming a recess having a desired mask pattern on the surface of the transparent substrate, laminating a light-shielding film on the surface of the transparent substrate on which the recess is formed, and then the light-shielding film fits in the recess; and A method for producing a photomask plate, comprising: polishing a surface of the transparent substrate so as not to protrude onto the surface of the transparent substrate to form a mask pattern.