Radiation imagery chemistry: process – composition – or product th – Diazo reproduction – process – composition – or product – Composition or product which contains radiation sensitive...
Reissue Patent
1999-11-24
2003-09-23
Chu, John S. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Diazo reproduction, process, composition, or product
Composition or product which contains radiation sensitive...
C430S191000, C430S192000, C430S270100, C430S286100, C430S287100, C430S906000, C430S909000, C430S910000
Reissue Patent
active
RE038256
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a safe photosensitive composition not containing any harmful compound and, more particularly, to a photosensitive compound suitably usable in the manufacture of, e.g., a display device or an image pickup device and a method of manufacturing a display device or an image pickup device using this photo-sensitive composition. The present invention also relates to a safe photosensitive composition suitably usable in the fabrication of various electronic parts or circuit boards requiring finer processing and a pattern formation method using this photosensitive composition.
2. Description of the Related Art
Conventionally, resists have been widely used in the formation of patterns in the fabrication of various electronic parts or circuit boards, including semiconductor integrated circuits such as LSIs, which require a number of micropatterning techniques, or in the manufacture of display devices such as CRTs and LCDs, or image pickup devices such as CCDs.
Representative examples of the resists used in the micro-patterning are resists containing acrylic resin, e.g., poly (methylmethacrylate) and poly(trifluoroethyl-&agr;-chloroacrylate), resists containing quinonediazide-novolak resin and currently beginning to be used in the mass production of LSIs, and chemical amplification type resists consisting of an alkali-soluble resin, a dissolution inhibitor, and an acid generator as disclosed in Jpn. Pat. Appln. KOKAI Publication No. 63-27829. It is unfortunate that any of these resists has a problem in safety since the resist is generally dissolved in an organic solvent to prepare a resist solution by which a coating film is formed. Therefore, a coater must be equipped with a local ventilating means.
On the other hand, a water-soluble resist which can be coated in the form of an aqueous solution and developed with water is also known. One example of this water-soluble resist is a photosensitive composition using ammon dichromate or a large quantity of a diazo compound, as a sensitizing agent, and also containing casein or polyvinyl alcohol as a water-soluble resin. Unfortunately, ammon dichromate is a special management substance having toxicity, and a large quantity of a diazo compound is also very harmful to a human body. Consequently, this photosensitive resin also has problems in safety and environmental pollution.
Of the resists enumerated above, those used as the resists in the manufacture of display devices or image pickup devices are a mixture of ammon dichromate or a bisazide compound and a water-soluble resist, and a resist containing photosensitive polyimide or a quinonediazide-novolak resin. These resists, therefore, have the same problems as the resists used in the micropatterning.
In addition to these resists, a so-called slurry photosensitive composition is known as a light-controlling resist playing a certain role in achieving the performance of a photo-related device, e.g., a fluoroscent resist of a CRT, or a light-shielding resist or a color filter resist of a display device or an image pickup device. This slurry photosensitive composition contains a powder of, e.g., a fluorescent substance, a dye, or a pigment and is thereby imparted the corresponding function of any of these materials. However, this powder as the component of the slurry photosensitive composition scatters or absorbs exposure light, resulting in a significantly decreased transparency of the resist. This consequently degrades the image formation capabilities such as resolution and sensitivity.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide two types of photosensitive compositions. The first photosensitive composition is a safe slurry photosensitive composition superior in image formation capabilities such as resolution and sensitivity and containing no harmful compound. The second photosensitive composition is a safe water-soluble photosensitive composition capable of being dissolved in water without using any organic solvent while maintaining a sufficient sensitivity as a resist, and containing no harmful substance.
It is another object of the present invention to provide a method of manufacturing various types of devices, particularly a CRT and an image pickup device, in which the manufacturing process is simplified and therefore high-quality products can be manufactured with a high yield.
It is still another object of the present invention to provide a pattern formation method capable of safely performing the process without using any special equipment such as a ventilator.
The first photosensitive composition of the present invention is characterized by containing i) a compound which generates an acid when irradiated with light or ionizing radiation, ii) at least one type of a resin with acid-crosslinkability or acid-decomposability, and iii) a powder.
The first photosensitive composition is a safe slurry photosensitive composition not containing any harmful substance such as a large quantity of a bisazide compound or a harmful metal ion. In addition, the image formation capabilities such as the resolution and the sensitivity of the first photosensitive composition are so excellent that they cannot be expected to be achieved in any conventional slurry photosensitive composition inferior in the resist transparency or the sensitivity during exposure.
The second photosensitive composition of the present invention is characterized by containing i) a compound which generates an acid when irradiated with light or ionizing radiation, and ii) at least one type of an acid-crosslinkable resin having repeating units represented by Formulas (1) and (2) below:
wherein R
1
represents a monovalent organic group.
The second photosensitive composition can be dissolved in water without using any organic solvent, contains no or almost no harmful substance, and has a sufficient sensitivity as a negative type and chemical amplification type resist. Consequently, the amount of an additive such as an acid generator can be reduced. Also, the process can be done safely since no special equipment such as a ventilator is required in using this composition.
The device manufacturing method of the present invention is characterized by including the steps of i) forming a layer of the first photosensitive composition on a substrate, ii) exposing the layer in accordance with a predetermined pattern, and iii) heating the layer to form a fine pattern of the powder contained in the photosensitive composition.
This device manufacturing method can directly form a pattern having an optical function, unlike in conventional pattern formation methods. Consequently, the manufacturing process can be simplified. As a result, defective portions, such as defects of the pattern, produced during the manufacturing process can be reduced, and this makes it possible to manufacture high-quality products with a high yield.
The pattern formation method of the present invention is characterized by comprising the steps of i) coating the second photosensitive composition on a substrate, ii) irradiating light or ionizing radiation on the substrate coated with the photosensitive composition in accordance with a predetermined pattern, iii) performing chemical amplification by heating the irradiated substrate, and iv) developing the chemically amplified substrate with water.
In this method the pattern formation can be safely performed without requiring any special equipment such as a ventilator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first photosensitive composition of the present invention, i.e., a safe slurry photosensitive composition superior in image formation capabilities such as resolution and sensitivity and containing no harmful compound will be described below.
Examples of a compound which generates an acid upon irradiation with light, i.e., an acid generator, and is preferably water-soluble for use in the first photosensitive composition of the present invention are an onium salt, a quinonediazide compound (particularl
Asakawa Koji
Hongu Akinori
Naito Takuya
Nakase Makoto
Niki Hirokazu
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