JPH0439820A - Pattern forming method - Google Patents

Abstract

PURPOSE:To obtain a pattern of a metal oxide film, metal film, metal sulfide film or metal nitride film having an excellent characteristic, which can be easily formed even on a substrate of a large size at a low cost, by spraying a solution or injecting gas under a normal pressure so as to form the film. CONSTITUTION:An ink composition is pattern-printed or deposited, followed by drying or hardening, and a pattern mask layer 3 including a filler 2 is formed by photolithography. While a substrate 1 with the mask layer 3 formed thereon is heated at a temperature higher than a pyrolysis temperature of a metal compound, a solution 4 of the metal compound is sprayed or gas of the metal compound or pyrolytic gas 5 is injected onto the substrate 1 so as to thermally decompose the metal compound, followed by baking. A forming film 6 of either of a metal oxide film, metal film, metal sulfide film and metal nitride film is formed on a portion, where no mask layer 3 is formed, of the substrate 1. Therefore, it is possible to obtain a method for forming a pattern of metal oxide film, metal film, metal sulfide film or metal nitride film having fineness and an excellent characteristic in a simple process.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to conductive films, transparent conductive films, etc. used in various electronic components such as liquid crystal display elements, solar cells, and A-density integrated circuits.
The present invention relates to a pattern forming method for patterning a metal oxide film, metal film, metal sulfide film, or metal oxide film constituting a resistive film, an insulating film, etc. on a substrate.

Conventional technology Conventionally, methods for forming patterns of metal oxide films, metal films, metal sulfide films, or metal oxide films on substrates include: (1) Vacuum evaporation method, sputtering method, CVD method, streak spray method Substrate (2) A method in which a film is uniformly formed on a substrate on which a negative pattern is formed using a resist material used as a mask layer, and then a film is formed uniformly on a substrate using a vacuum evaporation method or a sputtering method, and then a resist is etched with a solvent. The so-called lift-off method, in which a pattern is formed by cleaning the resist material and simultaneously removing the film formed on the resist material; (3) A method in which a pattern is printed directly on the substrate with a metal compound solution, followed by thermal decomposition and baking. etc. are well known.

Problems to be Solved by the Invention However, in the conventional method (1) above, wet etching using strong acids such as aqua regia or nitric acid is usually performed in the etching process, but this method The problem is that handling, management, waste liquid treatment, etc. require great care and cost. Another problem is that acid-stable metal oxides, such as tin oxide films, cannot be directly etched, requiring a more complicated process of performing a -degree reduction treatment and then etching. On the other hand, there is a method called dry etching, but in this case it requires operation in a vacuum container, which results in poor productivity, difficulty in processing substrates with large areas, and high equipment costs. Due to these issues, it is only used for special applications such as ultra-fine processing in semiconductors. In addition, in the film forming process, in the case of vacuum evaporation method, sputtering method, etc.
Since high vacuum is required, there are problems such as poor productivity, difficulty in forming a film over a large area, and high equipment cost.

Method (2) does not involve an etching process, but the film formation process is limited to vacuum evaporation and sputtering methods that require high vacuum, resulting in poor productivity, difficulty in forming films over large areas, and equipment costs. In addition to being expensive, there is also the drawback that the substrate cannot be heated above the decomposition temperature of the resist during film formation.

Method (3) is an effective method in that film formation and patterning can be performed at the same time, but depending on the metal compound, it is difficult to produce metal compound ink suitable for pattern printing, and thermal decomposition components may be generated during baking. Since it becomes a gas and scatters from within the film, the resulting metal oxide film, metal film, metal sulfide film, or metal oxide film lacks density in its film structure, resulting in electrical, 9 mechanical, and chemical There is a problem that the characteristics are inferior.

The present invention solves the above problems, and provides a method for forming a pattern of a metal oxide film, metal film, metal sulfide film, or metal oxide film that is dense and has excellent properties using a simple process. The purpose is to

Means for Solving the Problems The present invention, as a means for solving the above-mentioned problems, provides an organic powdery substance, an inorganic powdery substance, or A process of coating an ink composition containing these mixtures as fillers on a substrate and then drying or curing to form a patterned mask layer, and heating the substrate on which the mask layer has been formed to a temperature above the thermal decomposition temperature of the metal compound A process of thermally decomposing the metal compound on the substrate by spraying a solution of the metal compound or injecting a gas of the metal compound or a pyrolysis gas onto the substrate while heating it at a certain temperature and baking it, and removing the mask layer from the substrate after baking. This process consists of a step of peeling off and forming a patterned metal oxide film or metal film on the substrate.

Therefore, according to the present invention, an ink composition containing as a filler an organic powdery substance, an inorganic powdery substance, or a mixture thereof that does not decompose or evaporate or remains as a decomposition residue below the firing temperature of the metal compound. After coating the mask layer on the substrate, the substrate with a mask layer formed by drying or curing is heated at a temperature higher than the thermal decomposition temperature of the metal compound, and a solution of the metal compound is sprayed, or a gas of the metal compound or a pyrolysis gas is sprayed. By spraying, thermally decomposing and baking the metal compound, most of the resin binder in the mask layer disappears due to thermal decomposition, and the mask layer part forms a metal oxide film, metal film, and metal sulfide film on the remaining filler. The filler is either coated with one of the metal oxide films or mixed with the remaining filler and any of the metal oxide, metal sulfide, and metal oxide. In this state, it is in the form of flakes or powder, and its adhesion to the substrate is very weak, so it can be easily peeled off and removed by cleaning, and the metal oxide film can be applied to the necessary areas.
It is capable of forming patterns of metal films, metal sulfide films, or metal oxide films.

Examples (Fig. 1 fal, fb) for examples of the present invention.
.

(This will be explained using C1, fdl, and tel.

As shown in Figure 1 (al), a filler consisting of an organic powdery substance, an inorganic powdery substance, or a mixture thereof that does not decompose or evaporate or leaves decomposition residues below the firing temperature of the metal compound on the substrate l. 2 by drying or curing after pattern printing the ink composition contained in 2, or by photolithography after drying or curing after coating,
A patterned mask layer 3 containing a filler 2 is formed.

Next, as shown in FIG. 1 (bl), while heating the substrate 1 on which the mask layer 3 has been formed at a temperature higher than the thermal decomposition temperature of the metal compound, a solution 4 of the metal compound is sprayed onto it, or a solution 4 of the metal compound is sprayed onto it. When the metal compound is thermally decomposed by injecting gas or pyrolysis gas 5 and fired, a metal oxide film is formed on the substrate 1 in the area where the mask layer 3 is not present, as shown in FIG.
A film 6 of a metal film, a metal sulfide film, or a metal oxide film is formed, while a metal oxide film or a metal film is formed on the filler 2 remaining after baking the mask layer 3 portion.

The filler 2 is coated with either a metal sulfide film or a metal oxide film 7, or as shown in FIG. A mixed layer 8 is obtained. In addition, when the cell is sprayed with the metal compound solution 4 or the metal compound gas or pyrolysis gas 5 shown in FIG. Even if only the resin binder remains, the resin binder may be before or in the process of being thermally decomposed.

After baking the substrate 1, it is immersed in water and subjected to ultrasonic cleaning, brush cleaning, etc. to remove the filler 2 in the area where the mask layer 3 was provided and the metal formed thereon, as shown in FIG. Any film 7 of an oxide film, a metal film, a metal sulfide film, or a metal oxide film, or a filler and a metal oxide, a metal,
Mixed layer 8 in which either metal sulfide or metal oxide is mixed
Peel off.

Metal oxide film and metal film are removed and applied to the necessary areas.

Formed film 6 of either metal sulfide film or metal oxide film
complete the pattern.

Next, specific examples of the specific pattern forming method of the present invention will be described.

(Example 1) An ink composition for forming a mask layer 3 containing an inorganic powder material having the composition shown in Table 1 as a filler 2 is prepared by kneading it with a three-roll roll.

(Left below) Table 1 This ink composition was applied to a silica-coated soda glass substrate 1.
A mask layer 3 was formed by screen printing on the film and curing it by heating at 150° C. for 30 minutes. This substrate 1 with mask layer 3
was heated to 40°C, and then a solution containing tin 2-ethylhexanoate and antimony 2-ethylhexanoate (tin/antimony (weight ratio) = 10/1) was heated to 300°C under a nitrogen atmosphere. When fired by injecting pyrolysis gas obtained by heating, a film 6 made of an antimony-doped tin oxide film is formed on the part without the mask layer 3, and a film 6 made of an antimony-doped tin oxide film is formed on the part of the mask layer 3 on the filler 2 made of graphite and carbon. The tin oxide film 7 is coated, and by performing ultrasonic cleaning in water for 1 minute, the antimony-doped tin oxide film 7 is coated on the filler 2 made of graphite and carbon. can be completely removed, and the antimony-doped tin oxide formation film 6 can be formed with high precision. The resistance value of this formed film 6 is as low as 1.6 x 10 ohms, and even if left for 1000 hours under high temperature and high humidity conditions (60°C, 95% RH), the resistance value will change within 10%. , and has excellent mechanical strength.

(Example 2) Next, an ink composition for forming the mask layer 3 containing an organic powdery substance having the composition shown in Table 2 as the filler 2 is prepared by kneading it with a triple roll.

Table 2 This ink composition was applied to silica-coated soda glass substrate 1.
A mask layer 3 having a pattern with a line spacing and a line width of 10 μm was formed by photolithography. While heating the substrate 1 with the mask layer 3 to 450°C, a solution containing indium 2-ditylhexanoate and tin 2-ethylhexanoate (indium/tin (weight ratio) = 9.515) is sprayed onto it. Then, when the mask layer 3 is not present, a tin-topped indium oxide film 6. The mask layer 3 is filled with a filler 2 made of benzoguanamine resin.
The film 7 of tin-topped indium oxide was coated on the filler 2 made of benzoguanamine resin by ultrasonic cleaning in water for 1 minute. It is possible to completely remove the state portion, and a tin-topped indium oxide film 6 having a pattern with a line width of 10 μm can be formed with high precision. The resistance value of this formed film 6 is 1.2×10Ω・
It has a low resistance value of
H) Even if left for 1000 hours under conditions, the resistance value change is within 15%, and it has excellent mechanical strength.

Filler 2 in addition to those shown in Example 1 or Example 2 above
- Non-oxide-based inorganic powder materials such as boron nitride and silicon carbide; three-dimensionally crosslinkable thermosetting resin powders such as polyimide resins, phenol resins, and xylene resins; and heat-resistant materials such as fluororesin powders. It has been confirmed that a similar pattern can be formed using organic powdery substances such as organic powder. It was found that fusion with the substrate 1 is likely to occur, and the adhesion with the substrate 1 becomes considerably large after firing, making it difficult to remove the mask layer 3 in some cases.

In addition, examples of the metal compounds that can be used in the present invention include Example 1
Or tin 2-ethylhexanoate or 2-ethylhexanoate shown in Example 2.
- Antimono-ethylhexanoate The 2-ethylhexanoate of indium, such as indium 2-ethylhexanoate, as well as other organic acid salts, such as acetate, acrylate, propionate, benzoate, p-
Organic acid salts such as toluate, sulfate, etc. can be used in a similar manner. In addition, nitrates of these metals,
Similar effects were obtained using chlorides, fluorides, alkoxides, acetylacetonates, organometallic compounds, and the like. However, it was also found that the use of organic acid salts allows for the most stable film formation and is suitable for mass production because the compounds have excellent stability, are easy to handle, and have low toxicity. Furthermore, not only such soot, antimony, and indium compounds, but also those that are decomposed by heating to form the desired film 6 of a metal oxide film, a metal film, a metal sulfide film, or a metal oxide film. Materials other than those listed above can be used if available, such as silicon or titanium organic acid salts or alkoxides for silica films and titania films, halthenium organic acid salts for tinium oxide films, and gold resinates for gold films. It was confirmed that a similar pattern could be formed using this method. In the case of sulfide films such as zinc sulfide films and cadmium sulfide films, pattern formation can be performed using zinc or cadmium mercaptides or thiocarbamates in an atmosphere of nitrogen, argon, or hydrogen sulfide, and titanium nitride films can be formed using mercaptides or thiocarbamates of zinc or cadmium. In the film, a mask layer 3 with boron nitride as a filler 2 is used, and pyrolysis gas of titanium 2-ethylhexanoate is pyrolyzed in a nitrogen atmosphere while heating a substrate 1 made of sapphire to 1370°C, and then fired. This allows pattern formation.

The binder used in the ink composition for forming the mask layer 3 can be any binder as long as most of it disappears during firing. For example, when firing at a relatively low temperature, a cellulose-based binder can be used. , when firing at a high temperature of 500° C. or higher, polyimide or the like may be selected as appropriate.

As described above, according to the above embodiments, metal oxide films, metal films, metal sulfide films or metal sulfide films having excellent properties can be formed by a simple and highly productive method that does not require expensive equipment or etching processes required for vacuum systems. A pattern of metal oxide film can be formed.

Effects of the Invention As is clear from the above embodiments, the present invention has the following effects.

+11 A substrate with a formed film can be produced at low cost by a simple method that requires only heat treatment and cleaning, without using dangerous chemicals like the etching method, and without the need for processes that require great care and cost.

(2) Since film formation is performed by spraying a solution or injecting gas at normal pressure, there is no need for expensive equipment such as vacuum equipment, and therefore it is an advantage that film formation can be performed easily even on large-area substrates at low cost. metal oxide films, metal films,
A pattern of metal sulfide film or metal oxide film can be obtained.

[Brief explanation of drawings]

Figure 1 (al, fbl, +CL fd), tel
FIG. 3 is a process diagram for explaining a pattern forming method in an embodiment of the present invention. 1... Substrate, 2... Filler, 3...
...Mask layer, 4...Metal compound solution, 5
・・・・・・Metal compound gas or pyrolysis gas, 6.
... Formed film (any film of metal oxide film, metal film, metal sulfide film, or metal oxide film). Name of agent: Patent attorney Shigetaka Awano (1 person) +2
1 \

Claims (2)

[Claims] (1) Contains as a filler an organic or inorganic powdery substance that does not decompose or evaporate or leaves decomposition residues below the firing temperature of the metal compound, or a mixture of the organic powdery substance and the inorganic powdery substance. A step of coating an ink composition on a substrate and drying or curing it to form a patterned mask layer, and heating the substrate on which the mask layer has been formed at a temperature higher than the thermal decomposition temperature of the metal compound. Spraying a solution of the metal compound or injecting a gas or pyrolysis gas of the metal compound onto the substrate to thermally decompose the metal compound on the substrate and baking it, and peeling off the mask layer from the substrate after baking. A pattern forming method comprising the step of forming any one of a patterned metal oxide film, a metal film, a metal sulfide film, or a metal oxide film on the substrate by dropping the patterned film. (2) The pattern forming method according to claim 1, wherein the metal compound is an organic acid salt of a metal.