JPH033373B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pattern forming method used in microfabrication of various types of displays and semiconductor integrated circuits, and in particular, to a method for transferring a large pattern onto a transfer target plate. This invention relates to a pattern forming method useful for.

[Conventional technology]

A method using an optical pattern generator is known as a conventional pattern forming method. This optical pattern generator focuses light emitted from a light source such as a xenon lamp using a condenser lens, forms a rectangle that is magnified (e.g. 5 to 1 times) through a variable aperture, and then projects a reduced projection of this rectangle. Reduce through the lens (e.g. 1/5~
1/10 magnification) and exposes a transfer plate (for example, a photomask blank coated with resist) placed on an XY stage. Here, the variable aperture has a rectangular shape formed by four blades, and an arbitrary rectangular shape can be obtained by adjusting the interval between the facing blades. The XY stage is connected to a length measuring machine that uses light wave interference, a linear encoder, etc., and drives and adjusts the X and Y tables to position the pattern to be exposed on the transfer plate. . After the above exposure, a pattern is formed on the transfer plate through predetermined steps of development, etching, and resist peeling.

[Problem that the invention seeks to solve]

However, when the size of the pattern to be formed on the transfer plate becomes larger, it becomes necessary to increase the size of the length measuring machine to match the size of the pattern, and with this increase in size,
Due to the limits of machining accuracy, the accuracy of the length measuring machine decreases, which ultimately necessitates a decrease in pattern positioning accuracy. In addition, the resolution decreases due to the decrease in rectangular positioning accuracy due to the variable aperture.
Furthermore, the resolution of the reduction projection lens also decreases.

The present invention has been made to solve the above-mentioned problems, and provides a pattern forming method that improves pattern positioning accuracy and resolution even when the pattern size to be formed on a transfer plate becomes large. The purpose is to provide

[Means for solving problems]

The present invention has been made to achieve the above-mentioned object, and includes dividing a desired pattern into a plurality of parts to form each divided pattern, and adding an original mask inside or outside each of the divided patterns. a plurality of original masks on which alignment marks are respectively formed; and an alignment mask on which synthesis alignment marks are formed that match the original mask alignment marks and are in a positional relationship to synthesize the desired pattern from the divided patterns. After transferring the composite alignment mark by exposing the prepared transfer plate coated with a resist through the alignment mask, the transfer plate is developed and etched;
A transfer plate with a synthetic alignment mark on which the synthetic alignment mark is formed is manufactured by peeling off the resist, and then the synthetic alignment mark is transferred to the transfer plate with the synthetic alignment mark on which a resist is applied. Adapting the alignment mark for the master mask to the original mask, exposing the divided pattern one by one through the master mask, and then developing and etching the transfer plate containing the composite alignment mark,
This pattern forming method is characterized in that the desired pattern is formed by removing the resist.

[Effect]

According to the present invention, even if the desired pattern size is large, the unexposed portion or the exposed portion is transferred to the resist of the transfer plate through the original mask in correspondence with the divided pattern, and then the transfer plate is transferred all at once. Develop it,
By etching and peeling off the resist, it is possible to eliminate the above-mentioned disadvantages of increasing size, improve pattern positioning accuracy and resolution, and further improve manufacturing efficiency. Note that the alignment mark for the original mask is located on the transfer plate containing the synthesis alignment mark in a portion where the light-shielding film is removed in the etching process, so it is not transferred to the transfer plate containing the synthesis alignment mark.

〔Example〕

Examples of the present invention will be described in detail below. The desired large pattern of this embodiment is an F-shaped white large pattern 2 formed on a photomask 1 as shown in FIG. This large white pattern has a light shielding film on the outside of the pattern and not on the inside. This photomask 1 is made by coating a ^light -shielding film made of Cr _{and Cr} The film is selectively patterned to form a large F-shaped pattern 2, and the pattern area is 250 mm□.

This desired large pattern 2 is divided into four parts by inputting XY coordinate pattern data using an electron beam lithography system, and the pattern data shown in FIG.
and division pattern 3 as shown in d, respectively.
4, 5, and 6, and furthermore, as shown in FIG.
and within these divided patterns 3 to 6, original mask alignment marks 7,
8, 9, 10, 11, 12, 13, and 14 are also set on the pattern data. Next, as shown in FIG. 5, alignment marks 7 to 14 for the original mask are
Outline cross-shaped synthesis alignment marks 7' to 14' are set on the pattern data in a positional relationship to synthesize the desired large pattern 2 from the divided patterns 3 to 6 in accordance with the above.

Next, as a transfer plate for the above pattern data,
As shown in FIG. 6, a light-shielding film 16 (e.g. Cr film, film thickness 700 Å) formed by sputtering on a transparent substrate 15 (e.g. quartz glass) and a positive type coated by spin coater. Electron beam resist 1
7 (eg, PBS (manufactured by Chitsuso Corporation), film thickness 4000 Å) are prepared. Five photomask blanks are prepared. Note that the resist 17 is of a positive type, but
If you invert the pattern data, you can create a negative type (e.g.
CMS-EX (SS) (manufactured by Toyo Soda Kogyo Co., Ltd.) may be used.

For these five photomask blanks, division patterns 3 and original mask alignment marks 7,
8, alignment marks 9 and 10 for the division pattern 4 and the original mask, alignment marks 11 and 12 for the division pattern 5 and the original mask, alignment marks 13 and 14 for the division pattern 6 and the original mask, and a composition alignment mark 7. ′〜
14', and developed using a special developer (e.g., PBS exclusive developer (manufactured by Chitsuso Corporation)). After post-baking, an etching solution (e.g., ceric ammonium nitrate and The resist is etched using an aqueous solution containing perchloric acid, and then the resist is removed using a stripping solution (e.g. a mixture of concentrated sulfuric acid and hydrogen peroxide). Original masks 18, 19, 20 shown in Figures 3 a, b, c and d, respectively.
and 21, and the alignment mask 22 shown in FIG. 5 are manufactured.

Next, a translucent substrate 23 (e.g. soda lime glass, dimensions 280 mm x 2.3 mmt) on the light shielding film 24 (e.g. substrate 23) formed by sputtering method.
Cr film and Cr _x O _r film, total film thickness 700 Å), positive photoresist 25 (e.g. AZ-1350 (manufactured by Hoechst Japan Co., Ltd.) coated by roll coating method,
A photomask blank 26 having a film thickness of 8000 Å) is prepared.

Next, the alignment mask 2 shown in FIG.
2 is tightly fixed in a predetermined position in the center of a photomask blank 26, ultraviolet light is passed through the alignment mask 22 from above, and areas other than the alignment mask 22 are blocked by an aperture to form a photomask blank. 26 resist 25
exposed to light, developed using a special developer (e.g. AZ exclusive developer (manufactured by Hoechst Japan Co., Ltd.)), and developed using an etching solution (e.g. an aqueous solution of ceric ammonium nitrate and perchloric acid). After etching, the resist is removed using a stripping solution (e.g. a mixture of concentrated sulfuric acid and hydrogen peroxide) through a predetermined photolithography process. 14′ is transcribed,
A transfer plate 260 with alignment marks for synthesis as shown in FIG. 8 is manufactured.

Next, after applying a resist similar to the above-described positive type photoresist 25 on this transfer plate 260, the original mask 18 shown in No. 3a is applied to the transfer plate 260.
60, tightly fix it to the upper left side. At this time, the original mask alignment marks 7 and 8 of the original mask 18 and the synthesis alignment marks 7' and 8' on the transfer plate 260 are aligned and installed, respectively, through an optical microscope. Then, ultraviolet light is passed through the original mask 18 from above, and the area other than the original mask 18 is shielded from light by an aperture, and the resist on the transfer plate 260 is exposed to the resist pattern as shown in FIG. 1a. A plate 261 to be transferred is manufactured. On this transfer plate 261, an exposed portion 3' for a divided pattern corresponding to the divided pattern 3 of the original mask 18 is transferred, and an unexposed portion 27 is held in other areas.

Next, the previous original mask 18 is removed, and the third mask 18 is removed.
The original mask 19 shown in FIG. 1B is placed on the upper right side of the transfer plate 261 shown in FIG. 1A. At that time, the alignment marks 9 and 10 for the original mask of the original master 19 are compared to the synthesis alignment marks 9' and 1 on the transfer plate 261 through an optical microscope.
0' and install them. and,
The original mask 19 is closely fixed on the transfer plate 261, and as described above, ultraviolet light is passed through the original mask 19 from above, areas other than the original mask 19 are blocked by the aperture, and the transfer plate is exposed. 26
The unexposed portion 27 on the resist pattern 1 is exposed to light to produce a resist patterned transfer plate 262 as shown in FIG. 1b. This transfer plate 262 has an original mask 1.
A divided pattern exposed part 4' corresponding to the divided pattern 4 of 9 is newly transferred and formed, and a composite exposed part is formed by the previously transferred divided pattern exposed part 3' and the currently transferred divided pattern exposed part 4'. 28 is formed. Note that the areas that were not exposed this time and last time are held as unexposed portions 29.

Next, the previous original mask 19 is removed, and the third mask 19 is removed.
The original mask 20 shown in FIG. c is placed on the lower left side of the transfer plate 262 described above. At that time, the original mask alignment marks 11 and 12 of the original mask 20 are placed on the transfer plate 26 through an optical microscope.
2 and are placed in alignment with the synthesis alignment marks 11' and 12' on 2, respectively. Then, the original mask 20 is closely fixed on the transfer plate 262,
In the same manner as described above, ultraviolet light is passed through the original mask 20 from above, the area other than the original mask 20 is blocked by the aperture, and the unexposed portion 29 on the transfer plate 262 is exposed to the light, as shown in FIG. A transfer plate 263 with a resist pattern as shown in c is manufactured. This transfer plate 263 has an original mask 20
The exposed part 5' for the divided pattern corresponding to the divided pattern 5 is newly transferred and formed, and the previously transferred exposed parts 3' and 4' for the divided pattern are combined with the exposed part 5' for the divided pattern transferred this time. Exposure section 30
is formed. Here, too, the areas that have not been exposed so far are held as unexposed portions 31.

Finally, the original mask 20 is removed, and the original mask 21 shown in FIG. 3d is placed on the lower right side of the transfer plate 263 described above. At this time, the original mask alignment marks 13 and 14 of the original mask 21 are positioned and placed with the synthesis alignment marks 13' and 14' on the transfer plate 263, respectively, using an optical microscope.
Then, the original mask 21 is closely fixed on the transfer plate 263, and ultraviolet light is passed through the original mask 21 from above in the same manner as described above.
Areas other than 1 are shielded from light by an aperture, and the unexposed portion 31 on the transfer plate 263 is exposed to light to produce a transfer plate 264 with a resist pattern as shown in FIG. 1d. This transferred plate 264 includes
A new divided pattern exposed portion 6' corresponding to the divided pattern 6 of the original mask 21 is transferred and formed.
The exposed portion 3' for the divided pattern transferred previously,
4' and 5' and the exposed part 6' for the divided pattern of the current transfer form a composite exposed part 32. Here, too, the areas that have not been exposed so far are held as unexposed portions 33.

Next, the transferred plate 2 to which the composite exposure part 32 has been transferred is
64 using a special developer (e.g. AZ exclusive developer (manufactured by Hoechst Japan Co., Ltd.)) and etching using an etching solution (e.g. an aqueous solution of ceric ammonium nitrate and perchloric acid). This synthetic exposure area 32 is then subjected to a predetermined photolithography process in which the resist is stripped using a stripping solution (e.g., a mixture of concentrated sulfuric acid and hydrogen peroxide).
A desired large white pattern 2 similar to that shown in FIG. 2 corresponding to the above is formed. In addition, Figure 1 d
The synthesis alignment marks 7' to 14' under the resist in the synthesis exposure section 32 shown in FIG. 3 are removed during the above etching.

The exposed parts 3', 4', 5', and 6' for divided patterns transferred as described above are the exposed parts for divided patterns (ex. ', 4', 5') are transferred while shielding them from light, thereby preventing double exposure transfer in the contours and portions. In addition, in the composite exposure sections 28, 30, and 32 shown in FIG. 1, by processing the pattern data of the electron beam lithography device, the joining portion of the exposed portion for one of the divided patterns (e.g., FIG. 1b)
If double exposure is carried out by extending the joint part (broken line area) of the exposed part 3' for a divided pattern shown in 2 to the inside of the area of the exposed part 4' for the other divided pattern (exposed part 4' for a divided pattern). , composite exposure section (same as:
When the large white pattern 2 is formed through the photolithography process described above to prevent insufficient exposure of the joint part in the composite exposure section 28), the fine line light-shielding property of the joint part within the large white pattern 2 is reduced. The formation of a film can be prevented.

According to this embodiment, the pattern positioning accuracy is
The error was within about 5 ppm, and the pattern resolution was able to reach a pattern line width of 1 μm. Therefore, it was confirmed that it is possible to form a pattern with high positioning accuracy and optical resolution for a large pattern. Furthermore, since the photolithography process after exposing the four divided patterns was performed all at once, manufacturing efficiency could be improved.

In the above embodiments, the desired large pattern was a white pattern as shown in FIG. The present invention can also be implemented. Examples of this light-shielding film pattern are shown in FIGS. 6, 7, and 9 to 14.
This will be explained with reference to the figures.

The desired large pattern of this embodiment is an F-shaped light-shielding film large pattern 35 formed on a photomask 34 as shown in FIG. Other than this, it is the same as that shown in FIG.

Similar to the previous embodiment, such a large pattern 35 is also divided into four parts by an XY coordinate pattern data input operation using an electron beam lithography apparatus, and the pattern data is divided into four parts as shown in FIGS. 11a, b, c, and d, respectively. Set patterns 36, 37, 38 and 39,
Furthermore, as shown in FIG. 12, alignment marks 40, 41, 42, 43,
44, 45 and 46, 47 are also set on the pattern data. In addition, division patterns 36, 37, 38
and 39, light-shielding patterns 48, 49, 50 and 51 for preventing double exposure are similarly set on the pattern data within the pattern area of the desired large pattern 35, respectively. Next, the 13th
As shown in the figure, dividing patterns 36 to 39 are aligned with alignment marks 40 to 47 for the original mask.
Outline cross-shaped synthesis alignment marks 40' to 47' are set on the pattern data in a positional relationship for synthesizing the desired large pattern 35.

Next, as a transfer plate for the above pattern data,
Five photomask blanks similar to those shown in FIG. 6 are prepared. The resist 17 coated on this photomask blank is of positive type as in the previous embodiment, but may be of negative type by inverting the pattern data.

For these five photomask blanks, the division pattern 36, the light-shielding pattern 48, the original mask alignment marks 40 and 41, and the division pattern 3 set in the above-mentioned electron beam lithography apparatus.
7. Light-shielding pattern 49 and original mask alignment marks 42 and 43; division pattern 38; light-shielding pattern 50 and original mask alignment marks 44 and 45; division pattern 39, light-shielding pattern 51 and original mask alignment mark 4;
6, 47 and synthesis alignment mark 40'~
The original masks 52, 53, 54 and 55 shown in FIG.
An alignment mask 56 shown in FIG. 13 is manufactured.

Next, as in the previous embodiment, the photomask blank 26 shown in FIG. 7 is prepared as a transfer plate onto which the desired large pattern 35 of this embodiment shown in FIG. 10 is to be transferred. Then, the alignment mask 56 shown in FIG.
6, and pass ultraviolet light through the alignment mask 56 from above.
The area other than the alignment mask 56 is shielded from light by an aperture, and the positive photoresist 25 on the photomask blank 26 is exposed to light, and a predetermined photolithographic image is formed as in the transfer formation of the synthesis alignment mark in the previous embodiment. After the process, a white cross-shaped synthesis alignment mark 40'~
47' is transferred to produce a transfer plate 560 with alignment marks for synthesis as shown in FIG.

Next, a resist similar to the above-described positive type photoresist 25 is applied onto the transfer plate 560, and then the original mask 52 shown in FIG. 11A is closely fixed to the upper left side of the transfer plate 560. that time,
The original mask alignment marks 40 and 41 of the original mask 52 are placed on the transfer plate 5 through an optical microscope.
Synthesis alignment marks 40', 4 on 60
1' and install them. and,
Ultraviolet light is passed through the original mask 52 from above, and the area other than the original mask 52 is shielded from light by an aperture, and the resist on the transfer plate 560 is exposed to the ultraviolet light to form a resist patterned coating as shown in FIG. 9a. A transfer plate 561 is manufactured. This transfer plate 561
, unexposed portions 36' for dividing patterns and unexposed portions 4 for preventing double exposure corresponding to the dividing patterns 36 and the light shielding patterns 48 of the original mask 52, respectively.
8' has been transferred, and in addition, an exposed portion 57 of the original mask 52 through light transmission and an unexposed portion 58 due to the light shielding means in areas other than the original mask 52 have been transferred.

Next, the previous original mask 52 is removed and the first mask 52 is removed.
The original mask 53 shown in FIG. 1b is placed on the upper right side of the transfer plate 561 shown in FIG. 9a. At that time, the original mask alignment marks 42 and 43 of the original mask 53 are compared to the synthesis alignment mark 4 on the transfer plate 561 through an optical microscope.
2' and 43', respectively.
Then, the original mask 53 is closely fixed on the transfer target plate 561, and as described above, ultraviolet light is passed through the original mask 53 from above, and areas other than the original mask 53 are blocked from light by the aperture, and the image is transferred. The unexposed portion 58 on the plate 561 is exposed to light to form the transfer plate 5 with a resist pattern as shown in FIG. 9b.
62 will be produced. This transfer plate 562 includes the division pattern 37 of the original mask 53 and the light shielding pattern 4.
The unexposed portions 37' for divided patterns and the unexposed portions 49' for preventing double exposure corresponding to 9 are transferred, and in addition, the exposed portions 59 due to the light transmitted through the original mask 53 and the areas other than the original mask 53 are transferred. The unexposed portion 60 caused by the light shielding means is transferred.
Then, the unexposed part 37' for the divided pattern transferred this time and the unexposed part 3 for the divided pattern transferred
6' to form a composite unexposed area 61. here,
The light shielding means for areas other than the unexposed parts 48' and 49' for preventing double exposure and the original mask 53 is the joint part 62 of the composite unexposed part 61 and the composite unexposed part 61.
This is effective in preventing double exposure on the contours of the image and improving pattern accuracy.

Next, the previous original mask 53 is removed and the first mask 53 is removed.
The original mask 54 shown in FIG. 1c is transferred to this transfer plate 5.
Install it at the bottom left on top of 62. At that time, the original mask alignment marks 44 and 45 of the original mask 54 are placed on the transfer plate 562 through an optical microscope.
They are placed in alignment with the upper synthesis alignment marks 44' and 45', respectively. Then, the original mask 54 is closely fixed on the transfer plate 562, and ultraviolet light is applied to the original mask 56 from above in the same manner as described above.
4, the area other than the original mask 54 is shielded from light by an aperture, and the unexposed portion 60 on the transfer plate 562 is exposed to light to form a transfer plate 563 with a resist pattern as shown in FIG. 9c. Manufacture. On this transfer plate 563, unexposed portions 38' for divided patterns and unexposed portions 50' for preventing double exposure, which respectively correspond to the light shielding patterns 50 of the divided patterns 38 of the original mask 54, are transferred, and in addition, Exposed portion 63 due to light transmission of original mask 54
, and an unexposed portion 64 formed by the blocking means in areas other than the original mask 54 are transferred. and,
The unexposed portion 38' for the divided pattern transferred this time and the unexposed portion 36' for the transferred divided pattern 36'
7' to form a composite unexposed area 65. even here,
Unexposed parts 48', 49', 50' to prevent double exposure
and the light shielding means for areas other than the original mask 54.
This is effective in preventing double exposure at the joint 66 between the unexposed portions 36' and 38' for the divided pattern and the outline portion of the composite unexposed portion 65, thereby improving pattern accuracy.

Finally, the original mask 54 is removed, and the original mask 55 shown in FIG. 11d is placed on the lower right side of the transfer plate 563. At this time, the original mask alignment marks 46 and 47 of the original mask 55 are aligned and set with the synthesis alignment marks 46' and 47' on the transfer plate 563, respectively, using an optical microscope. Then, the original mask 55 is closely fixed on the transfer target plate 563, and the ultraviolet light is passed through the original mask 55 from above in the same manner as described above, and the area other than the original mask 55 is blocked by the aperture to be covered. The unexposed portion 64 on the transfer plate 563 is exposed to light to form a transfer plate 5 with a resist pattern as shown in FIG. 9d.
Manufacture 64. This transfer plate 564 includes the division pattern 39 of the original mask 55 and the light shielding pattern 5.
The unexposed portions 39' for the divided pattern and the unexposed portions 51' for preventing double exposure, which respectively correspond to 1, are transferred, and in addition, the exposed portions 67 due to the light transmission of the original mask 55 are also transferred. Then, the unexposed portion 39' for the divided pattern transferred this time and the unexposed portion 36', 37', 38' for the divided pattern transferred this time.
A composite unexposed portion 68 is formed. Again, 2
Unexposed parts 48', 49', 50' for preventing heavy exposure,
51' and the light shielding means for areas other than the original mask 55 are the unexposed area 37' (lower side) for the divided pattern.
This function effectively works to prevent double exposure at the joint 69 between 38' and 39' and the outline of the composite unexposed area 68, thereby improving pattern accuracy.

Next, the transferred plate 564 to which the composite unexposed area 68 has been transferred is subjected to the steps of development, etching, and resist peeling in the same way as the photolithography process after exposure in the previous embodiment, and the composite unexposed area 68 is transferred to the transfer target plate 564. A corresponding large-sized light-shielding film pattern 35 similar to that shown in FIG. 10 is formed. Note that the composition alignment marks 40' to 4 under the resist of the exposure parts 57, 59, 63, and 67 shown in FIG. 9b
7' is removed during the above etching.

Also in this embodiment, similar to the effect of the previous embodiment,
It was possible to form a pattern with high positioning accuracy and high resolution for a large pattern. Furthermore, since the photolithography process after exposing the four divided patterns was performed all at once, manufacturing efficiency could be improved.

The present invention is not limited to the embodiments described above. Of course, the desired pattern shape may be any other shape than the F-shape. Instead of the electron beam lithography device used as a means of forming the divided pattern, it is also possible to use an optical pattern generator or a method of forming an enlarged pattern using the artwork method and reducing it with a reduction camera to obtain the pattern. good. Further, the number of divisions is arbitrary as long as it is 2 or more. The alignment marks for the original mask and for synthesis can be of any shape and number as long as they provide alignment accuracy, and their positions can be within the pattern in the case of a white pattern, or within the light-shielding film pattern. In this case, it may be anywhere as long as it is outside the pattern and within the exposure possible area of an exposure device such as an electron beam lithography device that forms the divided pattern. Further, the original mask alignment mark may be a cross-shaped white outline, and the synthesis alignment mark may be a cross-shaped light-shielding film pattern. Regarding the photomask blank used as the transfer plate, multi-component glass such as aluminoborosilicate glass or quartz glass may be used instead of soda lime glass as the material for the light-transmitting substrate. Instead of chromium, transition metal elements such as tantalum, molybdenum, nickel, and titanium, silicon and germanium, alloys of these, oxides, nitrides, carbides, silicides, borides, and mixtures thereof ( For example, a single layer or a multi-layer stack of nitride carbides) may be used, and a vacuum evaporation method, an ion plating method, etc. may be used instead of a sputtering method as a film forming method. The transfer plate may be a display electrode substrate such as electroluminescence, a semiconductor substrate, an optical recording medium, etc. instead of a photomask blank, and the resist for these transfer plates may be a positive or negative photoresist. Alternatively, an electron beam resist may be used. In addition to the contact exposure method, a proximity exposure method, a mirror projection exposure method, a 1x projection lens exposure method, etc. may be used as a method for transferring the original mask to these transfer plates.

[Effects of the Invention] As described above, according to the pattern forming method of the present invention, even if the pattern size to be formed on the transfer target plate becomes large, the pattern is divided into a plurality of pieces, exposed and transferred, and then Since the steps of development, etching, and resist stripping are performed all at once, the positioning accuracy and resolution of the pattern can be increased, and manufacturing efficiency can be improved in the steps after exposure and transfer. It is of great value in forming patterns on large transfer plates.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the synthesis process in exposure transfer of divided patterns in an embodiment of the present invention, and FIG.
The figure is a plan view showing a desired large pattern in the same example, FIG. 3 is a plan view showing an original mask on which a divided pattern is formed in the same example, and FIG. 4 is a plan view showing the exposed area and the original mask in the same example. FIG. 5 is a plan view showing the alignment mark in the same embodiment and the desired large pattern. FIG. 6 is a plan view showing the original mask shown in FIG. 3 and the alignment mark shown in FIG. FIG. 7 is a cross-sectional view showing a photomask blank for transferring the division pattern and synthesis alignment mark in the same embodiment, and FIG. 8 is a cross-sectional view showing the photomask blank for producing a mask for the same embodiment. 9 is a plan view showing a transfer plate with alignment marks for synthesis in another embodiment of the present invention, FIG. 9 is a plan view showing a synthesis step in exposure transfer of divided patterns in another embodiment of the present invention, and FIG. 11th plan view showing a large pattern of
The figure is a plan view showing an original mask on which a division pattern is formed in another embodiment, and FIG. 12 is a plan view showing an exposed area, an alignment mark for the original mask, and a desired large pattern in another embodiment. , FIG. 13 is a plan view showing an alignment mask in another embodiment, and FIG. 14 is a plan view showing a transfer plate with a synthesis alignment mark in another embodiment. 1, 34... Photomask, 2, 35... Desired large pattern, 3, 4, 5, 6, 36, 37,
38, 39...Division pattern, 3', 4', 5',
6'...Exposed portion for transferred divided pattern, 3
6', 37', 38', 39'...transferred unexposed parts for divided patterns, 7, 8, 9, 10, 11,
12, 13, 14, 40, 41, 42, 43, 4
4, 45, 46, 47...Original mask alignment mark, 7', 8', 9', 10', 11', 1
2', 13', 14', 40', 41', 42', 4
3', 44', 45', 46', 47'...Synthesis alignment mark, 18, 19, 20, 21, 5
2,53,54,55...original mask, 22,5
6... Alignment mask, 26... Photomask blank (transfer plate), 27, 29, 31,
33, 58, 60, 64...unexposed portion, 28,
30, 32... composite exposure section, 48, 49, 50,
51...Shading pattern, 57, 59, 63, 67
...Exposed portion, 61,65,68...Composition unexposed section, 260,560...Transfer plate with alignment mark for synthesis, 261,262,263,26
4,561,562,563,564... Transferred plate onto which the divided pattern has been transferred.

Claims (1)

[Claims] 1 A plurality of original masks, each of which is formed by dividing a desired pattern into a plurality of parts to form a divided pattern, and each of which has an alignment mark for the original mask formed within or outside each of the divided patterns; and the original mask. An alignment mask on which a synthesis alignment mark is formed in a positional relationship to synthesize the desired pattern from the divided pattern in accordance with the mask alignment mark is manufactured, and the alignment mask is applied to a transfer plate coated with a resist. After transferring the composite alignment mark by exposing the composite alignment mark to light through a photoreceptor, the transfer plate is developed, etched, and the resist is removed, thereby producing a composite plate with a composite alignment mark on which the composite alignment mark is formed. Next, the original mask alignment mark is adapted to the synthetic alignment mark transferred to the transfer plate containing the synthetic alignment mark coated with resist, and the divided pattern is formed by exposing the original mask one by one to the synthetic alignment mark. After transferring, the pattern forming method is characterized in that the desired pattern is formed by developing, etching, and peeling off the resist on the transfer plate having the synthesis alignment mark.