JP3529967B2 - Manufacturing method of photomask blanks with alignment marks - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of photomasks used in the manufacture of semiconductor devices such as ICs and LSIs. More specifically, the present invention is used in pattern exposure drawing for the manufacture of photomasks. The present invention relates to a method of manufacturing a photomask blank that can be improved.

[0002]

2. Description of the Related Art A photomask is used as an original plate when forming a circuit pattern of a semiconductor element such as an IC or an LSI, and is composed of a light shielding layer mainly made of chromium, molybdenum or the like on a substrate such as quartz. It has a pattern. Usually, as shown in FIG. 6, a photomask blank in which a light-shielding layer mainly composed of chromium, molybdenum, or the like is provided on one surface of a substrate such as quartz is manufactured by processing. A method of manufacturing the photomask shown in FIG. 6 will be briefly described here. First, a substrate 610 made of quartz glass or the like (a light shielding layer 620 mainly composed of chromium, molybdenum, etc. is formed on one surface of FIG. 6 (a) almost entirely (FIG. 6 (b)), and the g-line is formed on the entire surface of the light shielding layer 620. (436n
m) or i rays (365 nm) or a resist 630 sensitive to ionizing radiation such as electron rays (FIG. 6C), and then g rays, i rays or electron rays corresponding to the resist 630 are applied. The resist 6 using the ionizing radiation 640 of
30 is selectively exposed and drawn in a predetermined pattern shape.
(FIG. 6D) Next, development processing is performed to form a resist pattern. In the case of a positive type resist, the exposed resist portion is removed and a resist pattern is formed. (FIG. 6 (e)) In the case of a negative type resist, the exposed resist portion is cured, so that the unexposed resist portion is removed by the development process to form a resist pattern. Then, if necessary, a descum treatment and a baking treatment are performed, and the exposed light shielding layer 620 is etched (corroded) according to the resist pattern to form a pattern of the light shielding layer (FIG. 6F).
The resist film 630 is removed and cleaning treatment or the like is performed to obtain a photomask 600. (FIG. 6 (g)) Incidentally, as the light shielding layer 620, a single layer film, a double layer film having a chromium oxide layer on the surface thereof, and a similar chromium oxide layer as the first layer and the third layer were provided. A three-layer film or the like is used.

As an exposure drawing method in the photomask manufacturing method shown in FIG. 6, a method of exposing and drawing an electron beam on a resist portion provided on a light shielding layer of a blank for a photomask is used by using graphic data. The electron beam exposure drawing apparatus is the mainstream, but in recent years, a drawing apparatus which uses graphic data and performs optical exposure drawing with excimer KrF light has also been used. In particular, as the electron beam exposure drawing apparatus, many raster scan type electron beam exposure apparatuses as shown in FIG. 5 are used. Since the device itself is widely known, details are omitted here. A raster scan type electron beam exposure apparatus is one that causes an electron beam to reach a predetermined position of a resist such as a blanks on a substrate to pattern a latent image on the resist. The position of the electron beam reaching the Franks is controlled by (scanning) control and the position movement control of the blanks. These electron beam exposure apparatuses are generally equipped with a system for measuring the amount of reflected secondary electrons, and have a function of detecting a substance existing at a beam irradiation position by a relative change in the amount of secondary electrons. . Therefore, the patterned line width can be measured and the pattern position can be calculated. That is, the center coordinates of the cross mark pattern can be calculated. Therefore, in the electron beam exposure drawing apparatus as shown in FIG. 5, generally, the pattern position measuring function is used to read the master pattern whose coordinate position is known to obtain the orthogonal coordinates (X, The orthogonality correction (Y axis) and the size correction are performed. This is the daily management for securing the drawing accuracy of the electron beam exposure drawing apparatus. Further, in the electron beam exposure drawing apparatus as shown in FIG. 5, blanks to be drawn are held in a dedicated cassette, and are automatically conveyed and clamped on a stage next to the drawing.

[0004]

However, with the miniaturization and high densification of semiconductor elements, there is a strict demand for miniaturization and high precision of the photomask pattern, and in the electron beam exposure drawing apparatus shown in FIG. Despite the above daily management, it is becoming difficult to deal with variations in exposure drawing position accuracy and exposure drawing position accuracy, and there is a need for such a correspondence. There are various possible causes for lowering the exposure drawing position accuracy and increasing the position accuracy variation. (1) Even if the daily management of the electron beam exposure drawing apparatus shown in FIG. Influence, and the orthogonal coordinates at the time of actual drawing and daily embedding do not always match,
(2) When exposure drawing is performed, the accuracy of the clamp position of the cassette holding the photomask blanks on the stage and the accuracy of the holding position of the blanks on the cassette are unstable. (3) Deflection of the cassette itself and the blanks themselves The amount also changes depending on the clamp state, and the position of the blanks on the stage is exposed and drawn with a certain degree of uncertainty. SUMMARY OF THE INVENTION The present invention is directed to provide a blank for a photo disk capable of improving the exposure drawing position accuracy and reducing the variation of the exposure drawing position accuracy. At the same time, it is intended to provide a method for producing such a blank for a photosuku.

[0005]

Means for Solving the Problems A method of manufacturing a blank scan for the alignment mark with the photomask of the present invention, in order to prepare the photomask for semiconductor device manufacturing, exposing the photoresist portion on the substrate using the graphic data at exposure drawing apparatus of a type to be drawn, manufacturing of photomask blanks to be drawn the pattern on the resist portion applied thereon
A granulation method, on one surface of a substrate transparent to exposure light when the semiconductor device manufacturing, and only set the light shielding layer made of a thin metal film having light shielding property with respect to the exposure light, patterning of the light shielding layer in areas not regions, in one location or multiple locations, the position of the blank during exposure drawing, the inclination, Ru provided an alignment mark for recognizing the distortion or the like on the drawing machine process
In addition, the alignment mark is provided on a seal adhered to the surface of the light-shielding layer, and the resist is provided.
However, a masking tape is applied so that the resist is not applied to the alignment mark area, and a seal is applied to the alignment mark area where the resist is not provided. And
The above-mentioned exposure drawing apparatus is an electron beam exposure drawing apparatus or an optical exposure drawing apparatus.

[0006]

[0007]

Method for manufacturing the alignment marked photomask blank of the effects of the present invention, by a configuration as this, to improve the exposure drawing position accuracy, it is assumed that can reduce the variation in the pattern exposure position accuracy. Specifically, a photomask block with an alignment mark of the present invention is used.
A blank for a photomask manufactured by the manufacturing method of LANX is an exposure drawing apparatus of a method of exposing and drawing a photoresist portion on a substrate using graphic data in order to manufacture a photomask for manufacturing a semiconductor element. A blank for a photomask in which a pattern is drawn on a resist portion applied on the one surface of a substrate transparent to exposure light at the time of manufacturing a semiconductor element, and a thin metal that shields the exposure light. A light-shielding layer made of a film is provided, and an alignment for allowing the drawing machine to recognize the position, inclination, distortion, etc. of the blanks at the time of exposure drawing in one or more places in the area other than the pattern drawing area of the light-shielding layer. This is achieved by having a mark. That is, the alignment mark of the blanks can be confirmed by using the above-described exposure drawing position pattern position measuring function immediately before or during drawing, and thus the difference between the measurement position and the design position is obtained,
From this, it is possible to correct so as to obtain an appropriate rectangular coordinate at that time. Also, the position of the blanks during drawing can be confirmed by automatically checking the alignment mark position during drawing, so even if the blanks move on the stage during drawing, the movement of the blanks follows the coordinate system. Can be automatically corrected. Even if you do not set the alignment mark accurately by setting a design value, measure the coordinate position of the alignment mark immediately before drawing,
It is also possible to make a correction for the purpose of correcting a relative positional fluctuation during drawing by checking the drawing periodically during drawing.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION With alignment mark of the present invention
Made by the method of manufacturing blanks for photomasks
The blanks for the alignment mark with a photo mask will be described with reference to Figure that. FIG. 1A is a plan view showing a blank for a photomask with an alignment mark of a reference example, and FIG. 1B is an enlarged view of an alignment mark portion of a dotted line portion of FIG. (C) is A in FIG. 1 (b)
1 is a sectional view taken along line 1-A2. Further, FIG. 2A shows a photomask with an alignment mark of the present invention.
FIG. 2B is a plan view showing a first example of a blank for a photomask with an alignment mark, which is produced by the method for producing a blank for blanks , and FIG. 2B is an alignment of a dotted line portion in FIG. FIG. 2C is an enlarged view of the mark portion, and FIG. 2C is a sectional view taken along line B1-B2 of FIG. 2B. 1 and 2, 100 and 101 are photomask blanks, 110 and 111 are substrates, 120 and 121 are light-shielding layers, and 130 and 131 are alignment marks.
Reference numerals 0 and 141 are resists, 150 is a seal, 151 is a base layer, 152 is an adhesive layer, and 153 is a metal layer. The present invention
Of blanks for photomasks with alignment marks
A blank for a photomask with an alignment mark produced by the manufacturing method is an exposure drawing apparatus of a method of exposing and drawing a photoresist portion on a substrate using graphic data in order to manufacture a photomask for manufacturing a semiconductor element, It is a blank for a photomask in which a pattern is drawn on a resist portion applied thereon. Then, a light-shielding layer formed of a thin metal film having a light-shielding property with respect to the exposure light is provided on one surface of the substrate which is transparent to the exposure light when manufacturing the semiconductor element, and in a region which is not the pattern drawing region of the light-shielding layer. Alignment marks are provided at one place or a plurality of places so that the drawing machine can recognize the position, inclination, distortion and the like of the blanks at the time of exposure drawing. In the reference example shown in FIG. 1, the alignment mark 130 is provided without a metal film in a predetermined portion of the light shielding layer, and in the first example shown in FIG. 2, the alignment mark 131 has the light shielding layer surface. It is provided on the seal 150 adhered to the. 1 and 2, alignment marks are provided at three corner end portions of the substrate, but the present invention is not limited to this. Also, the shape of the alignment mark is not limited to this.

As an exposure drawing apparatus to which the photomask blanks with alignment marks of the reference example and the first example are applied, there are an electron beam exposure drawing apparatus and an optical exposure drawing apparatus as shown in FIG. It is not limited to this.

The substrates 110 and 111 are required to be transparent to the exposure light used for manufacturing the semiconductor element, but ultraviolet rays such as g-line (436 nm) and i-line (365 nm) are used as the exposure light. In this case, quartz glass is usually used. The light-shielding layers 120 and 121 need to have a light-shielding property with respect to exposure light when manufacturing a semiconductor element.
When ultraviolet rays such as g-line (436 nm) and i-line (365 nm) are used as exposure light, it is usually a single layer mainly composed of chromium, molybdenum or the like, or a multi-layered structure formed of plural kinds of metals. Things are used. Resist 14
0 and 141 are selected in accordance with the exposure light (ionizing radiation) used for the exposure drawing at the time of producing the photomask. Incidentally, FIG.
2 shows a state in which a resist is applied, but a state before applying a resist may be called a photomask blank.

The base of the seal 150 of the first example shown in FIG. 2 may be an (anisotropic) conductive polyimide film or the like, and the adhesive layer 152 may be a conductive adhesive or the like. Examples of the metal layer 153 include a thin film made of chromium, silver, gold, or the like, a printed metal paste, or the like.

Next, a method of manufacturing the photomask blank 100 with an alignment mark of the reference example shown in FIG. 1 will be described with reference to FIG. First, a masking jig 160 is used to prevent a light-shielding layer from being formed on a predetermined portion of the substrate 110 (FIG. 3A) that has been subjected to a cleaning process, and the light-shielding layer 120 is formed on one surface of the substrate 110. Form. (FIG. 3B) The light shielding layer 120 is formed by sputtering, vapor deposition or the like. As a result, the alignment mark 130 is formed in the area other than the pattern drawing area. Then, using the masking tape 170, the alignment mark 1
30 is covered (FIG. 3C), and a resist 140 is applied. (FIG. 3D) After that, the masking tape 170 is removed to obtain the photomask blank 100. (Fig. 3
(E))

In the method shown in FIG. 3, masking is performed during sputtering or vapor deposition to form a portion of the alignment mark 130 without the light shielding layer 120, but the invention is not limited to this. For example, the alignment mark 130 may be formed by forming a light-shielding layer on the entire surface of the substrate 110 by sputtering, vapor deposition, or the like, and then performing steps such as resist coating, exposure, development, etching, and resist stripping. In the method shown in FIG. 3, the masking tape 17
Although 0 is attached to prevent the resist 140 from being applied to the alignment mark 130 area, the resist 140 may be applied onto the alignment mark 130 in some cases.

Next, a method for manufacturing the photomask blank 101 with an alignment mark of the first example shown in FIG. 2 will be described with reference to FIG. This is the reason why
Manufacture of blanks for photomasks with a liment mark
An example of an embodiment of a method will be described. First, the light shielding layer 121 is formed on the entire surface of one surface of the substrate 111 (FIG. 4A) that has been subjected to the cleaning treatment or the like. (FIG. 4B) Light-shielding layer 121
Is formed by sputtering or vapor deposition. Then
The alignment mark forming region is covered with a masking tape 171 (FIG. 4C ), and a resist 140 is applied.
(FIG. 4D) After that, the alignment mark 131 made of the metal thin film 153 is formed in the alignment mark formation region.
The sheet 150 provided with is fixed on the light shielding layer with the alignment mark 131 on the upper side through the adhesive layer 152.
(FIG. 4E) As a result, the alignment mark 130 is formed in the area other than the pattern drawing area.

(Production Example) Furthermore, for a photomask with an alignment mark of the present invention
A blank for a photomask with an alignment mark manufactured by the method for manufacturing a blank will be described with reference to a manufacturing example . First, a blank for a photomask of a reference manufacturing example will be given. Off Otomasuku blank for Reference Preparation example, since the reference example shown in FIG. 1, is provided so as to no metal film on a part of the light shielding layer. And FIG. 1 (a)
The alignment marks having the shapes shown in FIGS. 1B and 1C are provided at the three positions shown in FIG. Board 11
0 is a quartz glass substrate, and 10 is a light shielding layer 120.
A chrome thin film having a thickness of 00Å is provided, the widths D1 and D2 shown in FIG. 1B are set to 20 μm, and the overall sizes L1 and L2 are set to 120 μm, respectively. Made OEBR100) 5500Å
It is arranged thick. The alignment mark 130 and the light shielding layer 120 were formed by sputtering by the method shown in FIG.

Next, a blank for a photomask of Preparation Example 1 will be described. The blank for a photomask of Preparation Example 1 is
In the first example shown in FIG. 2, the alignment mark 13
1 is provided on the seal 150 adhered to the surface of the light shielding layer. Then, at the three positions shown in FIG.
(B), alignment marks having the shape shown in FIG. 2 (c) are provided. A quartz glass substrate is used as the substrate 111, and a 900 Å thick chromium thin film is provided as the light shielding layer 121. Widths D3 and D4 shown in FIG.
m, and the overall sizes L3 and L4 were each 120 μm, and a positive type electron beam resist (EBR9-HS31 manufactured by Toray Industries, Inc.) was arranged in a thickness of 400 Å.

[0017]

Industrial Applicability As described above, the present invention provides an exposure drawing apparatus of the type that uses a pattern data to perform exposure drawing of a photoresist portion on a substrate in order to manufacture a photomask for manufacturing a semiconductor device. It is possible to provide a method for producing a blank for a photomask, which is a blank for a photomask in which a pattern is drawn on a resist portion applied to, and which improves exposure drawing position accuracy and can reduce variations in exposure drawing position accuracy. . As a result, in the exposure drawing device,
It enables stable supply of high-definition photomasks, which was not possible with the conventional tube filling method.

[Brief description of drawings]

FIG. 1 is a view of a blank for a photomask with an alignment mark of a reference example.

FIG. 2 is a photomask with an alignment mark of the present invention.
Of photomask blanks with alignment marks manufactured by the manufacturing method

FIG. 3 is a sectional view showing a manufacturing process of a blank for a photomask with an alignment mark of a reference example.

FIG. 4 is a sectional view showing steps of an example of an embodiment of a method for manufacturing a blank for a photomask with an alignment mark of the present invention.

FIG. 5 is a schematic diagram of an electron beam exposure drawing apparatus.

FIG. 6 is a manufacturing process diagram of a conventional photomask.

[Explanation of symbols]

100, 101 Photomask blanks 110, 111 Substrates 120, 121 Light-shielding layers 130, 131 Alignment marks 140, 141 Resist 150 Seal 151 Base layer 152 Adhesive layer 153 Metal layer 160 Masking jig 170, 171 Masking tape 600 Photomask 610 Substrate

─────────────────────────────────────────────────── --Continued from the front page (56) Reference JP-A-2-280162 (JP, A) JP-A-63-161617 (JP, A) JP-A-56-107555 (JP, A) JP-A-5- 281705 (JP, A) JP-A-62-245265 (JP, A) JP-A-3-218006 (JP, A) JP-A 61-5252 (JP, A) Jitsukaihei 3-59634 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03F 1/00-1/16

Claims (2)

(57) [Claims] 1. An exposure drawing apparatus of a system for exposing and drawing a photoresist portion on a substrate using graphic data for producing a photomask for manufacturing a semiconductor device, wherein a pattern is formed on the resist portion coated thereon. A method of manufacturing a blank for a photomask in which a light-shielding layer made of a thin metal film having a light-shielding property for the exposure light is formed on one surface of the substrate transparent to the exposure light when manufacturing a semiconductor element. set only, in the region not a pattern drawing area of the light-shielding layer, at one location or multiple locations, the position of the blank during exposure drawing, in inclination, Ru provided an alignment mark for recognizing the distortion or the like to the drawing machine process, The alignment mark
Is provided on the seal adhered to the surface of the light shielding layer,
The alignment mark is characterized in that the resist is arranged such that a masking tape is attached so that the resist is not applied to the alignment mark area, and a seal is attached to the alignment mark area where the resist is not arranged. Made in blank scan for photo mask attached
Build method. 2. A method of manufacturing a blank for a photomask with an alignment mark, wherein the exposure drawing apparatus according to claim 1 is an electron beam exposure drawing apparatus or an optical exposure drawing apparatus .