JPH036014A - Resist coating substrate having exposed region; method and apparatus for its manufacture - Google Patents

Abstract

PURPOSE:To remove a resist in an exposed region automatically by a developing operation in a posterior process by a method wherein, after a substrate has been coated with a positive-type resist, the exposed region which uses a specific region of the substrate and which has been exposed by light corresponding to the resist is formed. CONSTITUTION:A substrate 10 is coated with a resist 11. Since the resist 11 is coated by using a conventional method, the resist 11 is swollen at an end-face part of the substrate 10. A mask 12 is arranged to the resist coating substrate; a specific region of the substrate 10 is exposed by using light having a specific wavelength; an exposed region 13 which has been exposed in advance is formed. Consequently, the resist in the exposed region 13 is removed automatically in a posterior developing process. Thereby, the resist at the end-face part of the resist coating substrate is removed satisfactorily during the process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photomask substrate used as an original plate during the manufacture of ICs, LSIs, etc., and in particular, to The present invention relates to a resist-coated substrate having a previously exposed area, a manufacturing method thereof, and a manufacturing apparatus.

Conventional technology] Conventionally, the method of forming a resist film on a photomask substrate is to drop resist onto the top surface of a substrate that is rotating at high speed and form a rectangular shape using centrifugal force acting on the resist. A commonly used method was to spread the resist over the entire surface of the substrate, then evaporate the solvent in the resist and dry it to obtain a uniform resist film.

[Problems to be Solved by the Invention] However, in the conventional resist coating method, because the boundary conditions are different, the edge portion of the substrate is coated with 3' in FIG.
A bulge of resist is formed as shown in the figure, and the thickness may exceed 1 μm in some cases.

In addition, in FIG. 4, 1 is a substrate made of glass or the like, 2 is
3 indicates a metal film such as chromium (Cr), and 3 indicates a uniformly coated resist film.

In addition, when the resist block is carried after drying or comes into contact with transportation jigs, it cracks or peels off as shown in Figure 5(a), and becomes a source of dust during the mask manufacturing process. Become.

Furthermore, in the plate making process, particularly in the metal film etching process, the pattern of the crack is transferred to the end surface of the metal substrate, as shown in FIG. 5(b). In the cracks on the end surface of the metal substrate transferred in this way, even after the photomask is completed, as shown by the broken line 6.7 in FIG. 111m, etc., and during subsequent mask cleaning, the peeled off metal fragments may re-adhere to the mask pattern portion, causing poor appearance of the photomask. In addition, Fig. 5 (b) and (c) are shown in the same figure (a>
FIG. 2 is an enlarged view of the portion indicated by 5 in FIG.

As a method for preventing pieces of metal (for example, chromium) from peeling off from the edge of the substrate after the mask is completed, there is a known method of masking the edge of the substrate in advance when forming a metal chrome film, and not forming a chromium film on that part. There is. In particular, areas where peeling occurs are areas where foreign matter or oil components from hands and fingers have adhered due to handling before film formation, reducing adhesion to the base, so avoid forming a chromium film on these areas. is a technology that can be easily conceived.

However, when an E B (Electron Beam) resist is applied to a substrate on which chromium is not formed on the end face as described above and a photomask is formed by electron beam exposure, the underlying glass is exposed on the end face of the substrate. Moreover, since charges are accumulated in the base glass due to irradiation with the electron beam, the electron beam is deflected around the substrate, causing a problem in that a predetermined mask pattern cannot be formed.

This problem will be explained with reference to FIG. 6 as follows.

In recent years, the mainstream photolithography technology used in semiconductor manufacturing is the reduction projection exposure step-and-beat method.
In this apparatus, a photomask approximately five times the original size is used. In addition to the main pattern, that is, the predetermined mask pattern, the photomask (reticle) is provided with alignment marks on the periphery for alignment with the pre-process plate making. The relative positional relationship between this alignment mark and this pattern has a great impact on yield and productivity as semiconductor integration is increasing. However, the positional accuracy of the alignment mark cannot be guaranteed. In other words, when using a substrate that does not have a chromium film formed on the end face, the electron beam is deflected at the periphery of the substrate as described above, and as shown in Figure 6, the alignment mark is moved away from the position A where it was originally formed. It is formed at the shifted position B. In addition, in FIG. 6, 8 indicates a portion where the underlying glass is exposed.

Such positional accuracy depends on the sensitivity of the EB resist used, the dose amount, the area of the exposed glass part, and the relative positional relationship with surrounding conductors (cassettes), and these factors include statistical fluctuation elements. , a constant amount of displacement does not always occur. For example, when an alignment pot mark was drawn on a polybutene sulfone resist using a vector type electron beam drawing device, it was confirmed that the position accuracy error was ±0.5 μm or more.

As mentioned above, masking during chromium film formation is not suitable for positive electron beam resists. Therefore, when removing chromium on the end face, it is necessary to draw the peripheral area with the drawing device itself or manually after creating the mask. It is necessary to reapply the resist and perform separate plate making. However, the former method is subject to restrictions on the substrate cassette holding area, and the latter method has the drawback that new defects may occur during the plate remaking process.

On the other hand, positive type photoresists do not have the above-mentioned problems. However, when using the contact exposure method, there are restrictions such that the master side mask must be larger than the copy blank and a pattern to be removed must be formed, and when using the step-and-repeat method, This goal can be achieved by using a stepper to illuminate the outer periphery of the building, but this is subject to time constraints.

The present invention solves the above-mentioned problems, and provides a resist-coated substrate having an exposed area from which the resist on the end face of the resist-coated substrate can be removed satisfactorily during the process, and a method and apparatus for manufacturing the same. The purpose is to

[Means for Solving the Problems] The present invention solves the above-mentioned problems of conventional resist-coated substrates by exposing specific areas of the resist-coated substrate, such as end face areas, to visible light or far-field radiation after coating the resist. This problem is solved by providing an already exposed area by pre-exposing with light or the like. The principle is shown in Figure 1. In the figure, 10 is a substrate, 11 is a resist film, 12 is a mask, and 13 is an exposed area.

In FIG. 1, a resist 11 is applied to a substrate 10. As shown in FIG. Note that the resist 11 is applied by a conventional method, so although it is not shown in FIG.
Reference numeral 1 denotes a raised portion at the end surface of the substrate 10, as shown at 3' in FIG.

A mask 12 is placed on such a resist-coated substrate, and a specific region of the substrate 10, the end face portion in FIG. 1, is exposed to light having a predetermined wavelength. As a result, an exposed area 13 that has been exposed in advance is formed. The resist in the exposed area 13 is automatically removed in a subsequent development step.

Now, since the unexposed area of the negative resist is removed in the development process, the resist on the end surface of the substrate is removed during the process without any measures being taken. Therefore, negative resists are not the object of the present invention, but positive resists are the object of the present invention. Since the positive resist is a photodegradable polymer, when the resist 11 is a photoresist, it is sufficient to expose it to visible light, but when it is an electron beam resist, it is necessary to expose it to a deep ultraviolet light source. There is.

[Operation and Effects of the Invention] In the present invention, after applying a positive resist to a substrate, a specific area of the substrate is exposed to light according to the resist used to form an exposed area. The resist in the exposed area is automatically developed in the subsequent process.
Moreover, it can be removed satisfactorily. Therefore, it is possible to effectively prevent peeling off from the end surface of the substrate during mask cleaning, entanglement of fallen metal pieces, etc., which conventionally occur.

Furthermore, the present invention is applicable not only to photoresists but also to electron beam resists.

[Example code] Examples will be described below with reference to the drawings.

FIG. 2 is a perspective view showing an example of an exposure apparatus for forming exposed areas, and in the figure, 21 is a resist-coated substrate;
2 is a holding chuck, 23 is an exposure apparatus main body, 24 is an exposure light source, 25 is a reflection mirror, and 26 is an exposure mask.

In FIG. 2, a resist coated substrate 21 coated with a predetermined resist is placed under an exposure mask 26 of an exposure apparatus main body 23 while being held by a holding chuck 22 . The exposure apparatus main body 23 includes an exposure light source 24 and a reflection mirror 25 therein, and the light emitted from the exposure light source 24 is irradiated onto the resist-coated substrate 21 by the reflection mirror 25 via an exposure mask 26. It goes without saying that the resist is a positive type resist.

The positional relationship between the resist-coated substrate 21 and the exposure mask 26 is as shown in FIGS. 3(a) and 3(b).

That is, the center portion of the resist-coated substrate 22 is masked and is not exposed, and only the end face portion of the resist-coated substrate 21 shown at 27 in a specific area (FIG. 3<a) is exposed. Note that the resist-coated substrate 21 and the exposure mask 26 are aligned using the holding chuck 22 and the head of the exposure apparatus main body 23, that is, the outer shape of the portion where the exposure mask 26 is placed. An appropriate distance is provided between the head and the resist-coated substrate 21, as shown in FIG. 3(b), so that close exposure is performed instead of close exposure. In addition, the head and holding chuck 22 are designed to prevent light from going around to the center of the resist coated substrate 21.
Anti-reflection treatment has been applied.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible. For example, the exposure apparatus main body 23 can be placed on a spinner cup, in which case the holding chuck 22
Spina's chuck will also serve as. In addition, a shutter mechanism is provided in the exposure apparatus main body 23, and the holding chuck 22
It is also possible to prevent resist overlapping when the head of the exposure apparatus body 23 is not close to the head of the exposure apparatus main body 23.

Further, the optical system of the main body of the exposure apparatus can be designed as appropriate, and it can also be constructed using other suitable transmissive optical members, etc., instead of a reflecting mirror.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the present invention in detail, FIG. 2 is a perspective view of the main body of the exposure apparatus, FIG. 3 is a diagram showing the positional relationship between the exposure mask and the resist-coated substrate, and FIG. 4 is a diagram showing the conventional resist coating. Figure 5 shows the swelling of the resist caused by the coating method. Figure 5 shows the cracks and peeling of the resist and metal film that occur in the conventional resist coating method. Figure 6 is the same. FIG. 3 is a diagram showing beam deflection. 10... Substrate, 11... Resist film, 12...
Mask, 13...Exposed area, 21...Resist coated substrate, 22...Holding chuck, 23...Exposure apparatus main body, 24...Exposure light source, 25...Reflection mirror 2
6...Exposure mask. Applicant: Dai Nippon Printing Co., Ltd.

Claims (3)

[Claims] (1) A resist-coated substrate having an exposed area, characterized in that after coating a positive resist, an exposed area is provided by exposing a specific area to light having a predetermined wavelength. (2) a first step of applying a positive resist to the substrate;
A second step of forming an exposed area by exposing a specific region of the substrate obtained in the first step to light having a predetermined wavelength.
A method of manufacturing a resist-coated substrate having a previously exposed area, comprising the steps of: (3) In an exposure device comprising an exposure device body including an exposure light source, an optical member, an exposure mask, and a holding chuck that holds a substrate coated with a resist, the exposure mask is coated with a resist. 1. A resist-coated substrate manufacturing apparatus having a previously exposed area, which is configured to expose only a specific area of the substrate.