JPH01164939A - Exposing method - Google Patents

Abstract

PURPOSE:To make it unnecessary to apply a oxygen shielding film and to attain a low cost by heating a resist and exposing it so that polymerization is simultaneously executed with light and heat. CONSTITUTION:A sample 3 where the resist 1 made of acryloid-based photosensitive resin is applied on a base material 2 is held on a sample board 5 equipped with a heating heater 4. And a mask 9, held on a mask holding board 7, to which a desirable pattern is printed is brought in to contact with the sample 3. After the temperature of sample or the temperature of sample board attains a specific temperature, an exposure shutter 12 is opened to start exposure. At such a time, thermal polymerization is performed as soon as a generated radical combines with a monomer and the combination is executed at a fast polymerizing speed. Thus, a stage for applying the oxygen shielding film is not needed and the reduction of the cost can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for exposing resists and the like in photolithography processes necessary for manufacturing semiconductors, electronic devices, and the like.

Conventional technology Conventionally, acryloid photosensitive resin has been used as a high-sensitivity resist, and the resist is coated on a glass substrate or semiconductor substrate, and then a resin such as polyvinyl alcohol is coated on top of the resist. Exposure is performed by irradiating ultraviolet light through a mask with a predetermined pattern. Resins such as polyvinyl alcohol are used to block oxygen, and during exposure, radicals generated from the photo-initiating material in the resist combine with oxygen molecules that have penetrated and diffused into the resist from the surrounding air. This prevents the monomer from not contributing to the polymerization.

Problems to be Solved by the Invention By applying an oxygen barrier film to the resist in this manner, patterning can be performed with low exposure power. However, by adding an oxygen barrier film, (1) peeling of the resist after exposure due to insufficient wetting of the resist and oxygen barrier film, (2) blurring of the mask pattern image (decreased resolution) due to the thickness of the oxygen barrier film, Furthermore, the most important problem is that an oxygen barrier film coating process (including pre-baking) is required, leading to increased equipment costs. In view of this, an object of the present invention is to provide an exposure method that can stably pattern the acryloid resist without using an oxygen barrier film.

Means for Solving the Problems In the present invention, in order to solve the above problems, a substrate coated with a resist is exposed to light suitable for photopolymerization while being heated to a predetermined temperature range.

Effect The effect of the technical means of the present invention is that the radicals of the photo-initiating material generated by light irradiation combine with the monomer, which is the photopolymerizable material, with a higher probability than the probability of annihilation by combining with oxygen, and It is thermally activated to promote radical transfer.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings. The figure is a partial configuration diagram showing the exposure method of the present invention.

In the figure, a sample 3 coated with a resist 1 on a base material 2 such as glass is held using a vacuum suction hole 6 on a sample stand 5 equipped with a heater 4, and a vacuum suction hole 8 is placed on a mask holding table 7. A mask 9 with a desired pattern printed thereon is held in close contact with the sample 3, and ultraviolet light is emitted from a high-pressure mercury lamp and collimated with uniform exposure power by an optical system (not shown). 10 to burn the pattern on the mask onto the sample. A temperature sensor 1 is embedded in the sample stand 5, and when the sample temperature or the sample stand temperature reaches a predetermined temperature after sample preparation, the exposure shutter 12 opens to start exposure. After that, in another development process, the resist in the non-irradiated areas is etched and peeled off, and then in the post-bake process, the remaining polymer in the resist is thermally crosslinked to increase its adhesive strength with the base material. .

Materials for the resist 1 include, for example, pigment-filled resists manufactured by Fuji Hunt Electronics Technology Co., Ltd., which are made of acryloid photosensitive resin, such as blue resist (trade name Color Mosaic R5, abbreviation CM-B), green resist (trade name Color Mosaic G, A red resist (trade name Color Mosaic R1, abbreviation CM-R), and a black resist (trade name Color Mosaic K, abbreviation CM-K) were used. A 1% by weight aqueous sodium carbonate solution was used as the developer.

Next, the operation of this embodiment will be explained. The main component of acryloid resist is a polyfunctional acrylate monomer, which also contains a halomethyl-5-) riazine compound as a photoinitiator. Occur. This radical combines with the acrylate monomer to generate further radicals in said monomer, which is polymerized and strengthened. The generated radicals combine with oxygen molecules diffused in the resist and are oxidized, but since the resist is heated at this time, the generated radicals combine with monomers and thermally polymerize at the same time, resulting in a fast polymerization rate. As a result, the bonding progresses.

Here, the resist heating must be performed before exposure, and can be achieved by detecting the temperature of the sample 3 coated with the resist 1 using the temperature sensor 11 described above.

If the temperature of the resist is 50° C. or lower, no thermal polymerization will occur and the resist will completely peel off during development, so stable patterning requires a resist temperature of about 80° C. or higher. Furthermore, it was necessary that the thermal crosslinking temperature of the binder polymer was lower than about 130°C.

Compared to the conventional polyvinyl alcohol-based oxygen barrier film coated with CM- resist, the exposure energy amount is 25 to 40 mJ/cm2, and the sensitivity is lower than the conventional exposure energy l122IIIJICII+2. is small. Regarding resolution, with the above exposure energy amount, line width thickening (difference between line width after development and mask pattern line width), which was conventionally 3 to 5 μm, has decreased to about 171 m. An improvement was observed.

Also, in the sample in which a polyvinyl alcohol-based oxygen barrier film was coated on the resist of the CM-, the temperature was 80% at the time of exposure.
When heated to ℃, the exposure sensitivity increases to about 1811IJICI1
12, which was found to slightly contribute to an improvement in sensitivity.

Effects of the Invention The present invention is a method in which the resist is heated and exposed, and polymerization is performed simultaneously using light and heat, so there is no need to apply an oxygen barrier film, and the manufacturing time and coating equipment can be reduced. , low cost can be achieved.

[Brief explanation of the drawing]

The figure is a block diagram of an exposure method according to an embodiment of the present invention. l...Resist, 2...Base material, 4...Heater, 5...Sample stage, 9...Mask, 10...
...Ultraviolet light, 11... Temperature sensor, 12...
·Shutter. Name of agent Patent attorney Toshio Nakao Number 01'' Figure 1 Procedure amendment form) % formula % 1 Display of case Patent application No. 323160 of 1988 2 Name of invention Exposure method 3 Make amendments Relationship with the patent case Patent application Person name 1006 Kadoma, Kadoma City, Osaka Prefecture Name
(582) Matsushita Electric Industrial Co., Ltd. Representative Tani
Akio I 4 Agent 571 Address 7, Matsushita Electric Industrial Co., Ltd., 1006 Oaza Kadoma, Kadoma City, Osaka Prefecture Contents of amendment: 0) Change ``Figure wa'' to ``Figure 1'' on page 7, line 12 of the specification. is corrected to ``. (2) Correct the drawing as shown in the attached sheet.

Claims (4)

[Claims] (1) An exposure method characterized by exposing a resist made of an acryloid photosensitive resin while heating it to a predetermined temperature range. (2) The exposure method according to claim 1, wherein the resist is heated in a temperature range of 80°C to 130°C. (3) The exposure method according to claim 1 or 2, wherein a heater is provided as a means for heating the resist on a stand that supports the base material coated with the resist. (4) Claim 1, in which the temperature of the substrate or the support stage is detected and the exposure is started after reaching a certain temperature or higher.
Exposure method according to item 1 or 2.