JPH11236678A - Apparatus for forming metallic thin film pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for forming metallic thin film patterns capable of inexpensively and easily manufacturing the pattern images of the fine metallic thin films having the high uniformity of the film thickness of the metallic thin films to a high degree with the decreased fluctuations in line width. SOLUTION: This apparatus has an aq. soln. mixing system 10 which has a housing region 11 separately housing an aq. soln. A contg. at least a water-soluble metal compd. and an aq. soln. B contg. a reducing compd. and a mixing region 12 for mixing both aq. solns. and a treatment tray 30 which has a heating section 32 for heating a substrate having the fine resist pattern formed by using a photoresist material on the surface and has a liquid mixture contact means 31 for bringing the aq. soln. mixture supplied from the aq. soln. mixing system 10 into successive contact with the substrate 20 from the prescribed surface side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fine metal thin film pattern typified by a printed wiring board, a semiconductor circuit, and a metal wiring of a flat image display device such as a liquid crystal display or a plasma display in the field of the electronics industry. The present invention relates to a device capable of performing the following. More specifically, the present invention relates to a high-precision metal thin-film pattern forming apparatus capable of faithfully reproducing a resist pattern with high sensitivity and high resolution.

[0002]

2. Description of the Related Art In the recent field of electronics industry, fine metal pattern circuits are used for printed wiring boards, semiconductor electric circuits, electric wiring to image elements for various electronic image displays, and the like. Display devices have been increasing in size, and are large, suitable for use in electric circuits for large displays such as plasma displays. Development and improvement are required.

With respect to a method of forming a circuit having a fine metal pattern, means such as application of a printing method, vapor deposition, and sputtering are used. The printing method is a simple method typified by an example in which an Ag paste is printed in a pattern, but there is a limit to miniaturization of the pattern. There are weak points. In addition, the vapor deposition method or the sputtering method is a method of forming a fine pattern with a photoresist or a dry film and then depositing a metal in a gas phase on a substrate surface to form a pattern of a metal circuit, but the apparatus is expensive. The weak point is that it is difficult to control the deposited metal thickness to be uniform when the substrate has a large area.

As described above, the existing method is inexpensive, but the patterning accuracy is poor, and only a pattern with many defects can be obtained. In one of the ways,
There has been no apparatus capable of generating a metal pattern that can meet the three demands of high accuracy of the pattern circuit, large size, and low cost.

[0005]

SUMMARY OF THE INVENTION The present invention solves the problems of the above-described method of producing a metal wiring pattern by a printing method, a vapor deposition method, and a sputtering method, and has a high uniformity of the thickness of a metal thin film and a variation in a line width. It is an object of the present invention to provide a metal thin film pattern forming apparatus capable of easily and inexpensively producing a pattern image of a highly fine metal thin film with less.

[0006]

SUMMARY OF THE INVENTION The inventor of the present invention has proposed a method of spontaneously reductive precipitation of a thin metal wire constituting a metal wiring from a solution system by liquid-liquid reaction or spontaneous precipitation from a solid-liquid reaction system. The inventor of the present invention has conducted intensive studies on the belief that the production by electrolytic plating leads to the production of an inexpensive and highly accurate pattern. That is, the present invention has the following configuration.

[0007] 1. An aqueous solution mixing system including a storage region for separately storing an aqueous solution containing at least a water-soluble metal compound and an aqueous solution containing a reducing compound, and a mixing region for mixing both aqueous solutions, and a photoresist material. Tray having a heating unit for heating a substrate having a fine resist pattern on its surface, and a mixed liquid contacting means for sequentially contacting the mixed aqueous solution supplied from the aqueous solution mixing system with the substrate from a predetermined surface side When,
An apparatus for forming a metal thin film pattern, comprising: 2. The metal thin film according to claim 1, further comprising: a cleaning unit that removes the mixed aqueous solution remaining on the substrate after the processing in the processing tray; and a peeling unit that peels off only the resist pattern portion after the cleaning. Pattern forming device.

[0008] 3. The mixed liquid contacting means is a member having a length equal to or greater than the width of the substrate, and a supply port for supplying the mixed aqueous solution to the substrate faces the processing liquid and the processing liquid is substantially parallel to the substrate surface. 3. The apparatus for forming a metal thin film pattern according to the above 1 or 2, wherein the apparatus is configured to be movable on a tray. 4. 4. The metal thin film pattern forming apparatus according to the above item 3, wherein the supply port is formed as a slit.

[0009] 5. An aqueous solution supply system including a storage area for separately storing an aqueous solution containing at least a water-soluble metal compound and an aqueous solution containing a reducing compound, and a supply pipe for separately supplying both aqueous solutions, and formed using a photoresist material. A heating unit for heating a substrate having a fine resist pattern formed on the surface thereof, and each aqueous solution supplied from the aqueous solution supply system being sprayed from the predetermined surface side to the substrate and brought into contact sequentially while mixing and mixing the liquids 5. a processing tray provided with liquid contact means; The metal thin film according to claim 5, further comprising: a cleaning unit that removes the mixed aqueous solution remaining on the substrate after the processing in the processing tray; and a peeling unit that peels off only the resist pattern portion after the cleaning. Pattern forming device.

Here, the operation of the present invention will be described. In the aqueous solution mixed system, a storage area for separately storing at least an aqueous solution containing a water-soluble metal compound and an aqueous solution containing a reducing compound, and both aqueous solutions are referred to as alkaline aqueous solutions (sometimes referred to as a metal precipitation treatment liquid). ). Then, the mixed solution is applied to the substrate on which the resist pattern is formed in advance from a predetermined surface side by a mixed solution contact means on a processing tray. Thereafter, the processing tray is heated to a predetermined temperature by a heating unit provided on the processing tray, whereby metal precipitation starts to form a metal pattern mainly on the substrate.

This temperature is in the range from room temperature to 90 ° C. at a suitable temperature for each oxidation and reduction system. An appropriate time is also selected for the processing time. Usually, it is preferable to select reaction conditions such that the metal precipitation is completed within about 10 minutes within several seconds or more. If the treatment time is too short, it indicates that the activity of the metal precipitant is too strong.In such a case, the metal is precipitated on a portion other than the substrate, or the metal fine particles are contained in the metal precipitant. Precipitates. The activity of the metal precipitant is the water-soluble metal compound described below,
The precipitation rate can be adjusted by adjusting the respective concentrations of the complex forming compound and the reducing agent and the pH of the solution. After washing after the formation of the metal pattern, the resist pattern is stripped with a stripper to complete a fine metal thin film pattern. The condition under which the metal pattern is formed by the natural precipitation is an aqueous solution containing a water-soluble metal compound and a reducing agent, and the oxidation potential of the reducing agent is lower (lower) than the reduction potential of the water-soluble metal compound. Potential).

The water-soluble metal compound to be used in the present invention is:
Any metal can be used as the metal pattern. In other words, as described later, the conditions for precipitating the desired metal can be adjusted by selecting the reducing agent and the pH.
Any metal compound that is practical as a conductive circuit is an object of the present invention.

Next, the metal oxide applicable to the water-soluble metal compound of the present invention will be described. Since it is relatively easy to select a reducing agent from among a large number of reducing compounds, or to adjust the oxidation potential after selection, the practical purpose of the metal pattern as described above is used in selecting a metal compound. It is possible to use metal compounds of any suitable metal in light of the above. Metals that have practical value and are suitable for the application of the present invention are stable metals having low electric resistance and hard to corrode. It has a lower ionization tendency than the chromium element, that is, is noble. These metal elements include chromium,
Cobalt, nickel, tin, titanium, lead, iron (III), copper,
Molybdenum, tungsten, rhodium, iridium, palladium, mercury, silver, platinum and gold.

Among these, particularly preferred metal elements constituting the metal compound are silver, copper, nickel, lead, palladium, gold, platinum, tungsten, titanium, cobalt, and chromium. Gold, silver and copper satisfy all practical requirements such as stability against oxidation, toughness and flexibility in forming fine metal circuits.

Next, the reducing agent combined with the water-soluble metal compound will be described. The condition of the reducing agent is that the oxidation potential of the reducing agent is lower than the reduction potential of the metal compound to be combined in the aqueous solution system,
The practical meaning is that the maximum potential of the oxidation wave of the reducing compound is more negative (base side) than the maximum potential of the reduction wave of the metal compound. More preferably, the reduction potential of the metal compound is more noble than the oxidation potential of the reducing compound by at least 20 mv. Specific examples of the reducing agent include: (1) Saccharides and carbohydrates Saccharides and carbohydrates such as starch in a polymerized form thereof are suitable reducing agents in the present invention. Originally, its reducing property is considered to be age, but in an alkaline environment, its reducing property sufficiently reduces noble metal salts and heavy metal salts. In addition, since it can be present at a high concentration and the reduction reaction proceeds uniformly, it is possible to accurately form even a fine pattern. Preferred compounds include dextrins, but other monosaccharides and polysaccharides can also be used. (2) Aldehydes As can be considered from examples of Fehling's solution, aldehydes can be used as the reducing agent used in the present invention. (3) Developing agents Hydroquinones, catechols, catechols and the like, which are known as photographic developing agents, are used. In conjunction with this developing agent, a complex forming compound is used. Regarding the complexing compound for this silver ion, THJame
s, The theory of photographic processes 4th ed.
(McMillan) "on pages 8-11.

Here, an aqueous solution of a water-soluble metal compound, an alkaline aqueous solution of a reducing agent, or an alkaline aqueous solution also called a treating solution for metal precipitation having a composition in which both are mixed, have an appropriate pH value.
An alkali agent for adjusting to H and, if necessary, a pH buffering agent for maintaining the pH stably are added. As the alkali agent or buffer, alkali metal hydroxide,
Alkaline earth metal hydroxides, carbonates, phosphates, borates, tetraborates, hydroxybenzoates, glycyl salts,
N, N-dimethylglycine salt, leucine salt, norleucine salt, guanine salt, 3,4-dihydroxyphenylalanine salt, alanine salt, aminobutyrate, 2-amino-2-
Methyl-1,3-propanediol salt, valine salt, proline salt, trishydroxyaminomethane salt, lysine salt and the like can be used. In particular, carbonate, phosphate, tetraborate, and hydroxybenzoate have excellent buffering capacity in a high pH region of pH 9.0 or more.

In an alkaline aqueous solution containing a water-soluble metal compound and a reducing agent, and more preferably also containing a complexing agent for the metal, the precipitation of the metal is further promoted uniformly and smoothly, and the precision of the formed metal pattern is improved. A surfactant can be added to improve the viscosity. Surfactants,
Any nonionic, anionic (both amphoteric), or cationic surfactants may be used as long as they reduce the contact angle between the aqueous solution and the substrate material. Further, a water-soluble polymer may be added.

As the substrate, a glass substrate, a silicon wafer, or a plastic substrate is used. As the glass substrate, besides ordinary soda glass, various kinds of known glass such as optical glass and heat-resistant glass can be used according to the purpose.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a metal thin film pattern forming apparatus according to the present invention will be described below. FIG. 1 is a schematic view showing a first embodiment of a metal thin film pattern forming apparatus according to the present invention. FIG. 2 is an enlarged perspective view of a main part showing a back surface of the contact unit in FIG. FIG.
FIG. 2 is a schematic view showing a second embodiment of the metal thin film pattern forming apparatus according to the present invention. FIG. 4 is an enlarged perspective view of a main part showing a back surface of the contact unit in FIG.

(First Embodiment) As shown in FIG. 1, a metal thin film pattern forming apparatus 1 of the present embodiment comprises an aqueous solution mixing system 10, a processing tray 20, a cleaning unit 40, and a peeling unit 50. And The aqueous solution mixing system 10 has a storage area 11 for separately storing an aqueous solution A containing a water-soluble metal compound and an aqueous solution B containing a reducing compound. The aqueous solution A is supplied to the mixing region 12 through the supply region 12.
B is mixed.

The processing tray 20 has a heating unit 32 for heating one substrate 20 having a fine resist pattern formed on the surface thereof using a photoresist material.
The heating unit 32 is provided close to the back side of one substrate 20, and is a heating means for rapidly and precisely setting the substrate 20 to a temperature suitable for forming a metal thin film. Further, there is provided a mixed liquid contact means 31 for sequentially bringing the mixed aqueous solution supplied from the aqueous solution mixing system 10 into contact with the substrate 20 while moving (moving in the direction of the arrow X) on the predetermined surface side.

If the cleaning section 40 has a cleaning structure for removing the mixed aqueous solution remaining on the substrate 20 after the processing in the processing tray 30, for example, a structure in which water is stored in a water washing layer, An appropriate configuration such as a configuration in which washing water is supplied like a shower can be adopted.

The stripping section 50 is an area where the resist pattern is stripped. The stripping section 50 includes, for example, a stripping solution tank 52 of an appropriate size containing a stripping solution. Is placed in the tray with the top facing upward, and the stripping liquid is sprayed by a nozzle 54 extending from the stripping liquid tank 52. The resist is stripped by the synergistic action of the chemical reaction of the stripping liquid and the blowing pressure.

As shown in FIG. 1, the mixed liquid contact means 31 is a member having a length equal to or greater than the width of the substrate 20, and a supply port 31a for supplying the mixed aqueous solution to the substrate 20 is provided. They are facing as shown in FIG. Further, the mixed solution contacting means 31 is appropriately held (not shown) so as to be movable on the processing tray 30 (moving in the direction of the arrow X) substantially parallel to the surface of the substrate 20. The movement in the X direction is appropriately performed by a drive system (not shown).

In the present embodiment, the mixed liquid contact means 31 can be constituted, for example, as an elongated rod-shaped member as shown in FIG. 2, and the supply port 31a is formed in a slit shape along the longitudinal direction. It is configured. That is, the mixed aqueous solution supplied by the pipe 16 is sent out as a curtain-like thin film by the slit-like supply port 31 a and supplied onto the substrate 20. Therefore, since the mixed aqueous solution is supplied only to a region required for the thin film forming process, the mixed aqueous solution can be effectively processed without waste. In addition, both aqueous solutions A and B are temperature and pH.
Due to the balance between the two, some metal deposition may occur at the time of mixing, but immediately after mixing, the substrate 2
Since it is supplied above zero, the degree of metal precipitation is small, the unexpected deterioration and stagnation of the liquid are small, and therefore, an aqueous solution with a small concentration change can be supplied. The pipe 16 is made of a flexible material. Therefore, the movement of the mixed liquid contact means 31 can be allowed.

Next, a processing method using the above-described apparatus 1 will be briefly described. First, the substrate 20 having a fine resist pattern formed on the surface using a photoresist material is placed in the processing tray 30. Although not shown, this is carried out by arm transfer of the substrate, conveyor transfer for each tray 30 or the like. Thereafter, at the position of the mixed liquid contacting means 31, while supplying the mixed aqueous solution obtained by mixing the aqueous solution A containing the water-soluble metal compound and the aqueous solution B containing the reducing compound to the mixed liquid contacting means 31, The means 31 is moved relatively parallel to the substrate 20.
By this movement, the mixed liquid can be brought into contact with the entire surface of one side surface of the substrate 20. Here, the temperature is raised from the lower part of the tray 30 to a predetermined temperature by the heating unit 32 to start metal deposition. After that, the substrate 20 processed in the processing tray 30
Is removed from the processing tray 30 and moved to the cleaning unit 40, and the mixed aqueous solution remaining on the substrate 20 is appropriately cleaned and removed. After that, the substrate 20 having been subjected to the cleaning process is moved to a peeling section 50 where the resist pattern is peeled, and a peeling process is performed. By repeating such operations sequentially, a highly accurate and accurate metal thin film forming process can be performed.

(Second Embodiment) As shown in FIG. 3, a metal thin film pattern forming apparatus 13 according to a second embodiment
It has an aqueous solution supply system 70 (including the liquid contact means 71), a processing tray 20, a cleaning unit 40, and a peeling unit 50. Note that, in this embodiment, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

In the second embodiment, an aqueous solution supply system 70 is provided in an accommodation area 1 for separately containing an aqueous solution A containing a water-soluble metal compound and an aqueous solution B containing a reducing compound.
1, and the two aqueous solutions A, B
Are supplied to the distributors 14A and 15B via the. Distributor 1
4A is provided with a plurality of pipes 60A.
Are connected to the liquid contact means 71. Meanwhile, the distributor 15
B is provided with a plurality of pipes 60B.
Are alternately connected to the liquid contact means 71 with the pipe 60A.

In the second embodiment, the liquid contacting means 71 can be constituted, for example, as an elongated rod-like member as shown in FIG.
The spray ports 62 connected to 0A and the spray ports 63 connected to the pipe 60B are arranged alternately. Therefore, the two aqueous solutions A, B supplied by the respective pipes 60A, 60B
Forms a mixed spray liquid while being sprayed from the spray port, and the mixed spray liquid is supplied onto the substrate 20. After the liquid is applied to the entire surface of the substrate, the temperature is raised by the heating unit 32 to start metal deposition.

As described above, since the aqueous solution supplied to the substrate 20 is mixed with the aqueous solutions A and B simultaneously with the supply of the aqueous solution to the substrate 20, the aqueous solution can be supplied only to a region necessary for the thin film forming process. Effective processing can be performed without waste. In addition, since both aqueous solutions A and B are supplied onto the substrate 20 while being mixed, it is possible to supply an aqueous solution of a stable quality without any unexpected alteration or stagnation of the liquid and without a change in concentration. it can.

Here, in the second embodiment, the temperature is raised by the heating unit 32 disposed on the lower surface of the processing tray 30. In addition, a heating unit is disposed on the liquid contact unit 71. can do. With such a configuration, since the aqueous solutions A and B are in a mixed state immediately after being injected, metal deposition is started at this time.

[0032]

As described above, according to the apparatus of the first aspect of the present invention, the mixed liquid contact means has a supply port for the mixed liquid corresponding to the substrate width, and the mixed aqueous solution is supplied to the curtain. Since the thin film can be discharged as a thin film and supplied onto the substrate, the mixed aqueous solution is supplied only to a region necessary for the thin film forming process, and the mixed aqueous solution can be effectively processed without waste. Further, since the two aqueous solutions A and B are supplied to the substrate immediately after being mixed, a stable quality aqueous solution can be supplied without any unexpected alteration or stagnation of the liquid and without a change in concentration.

Further, according to the apparatus according to the fifth aspect of the present invention, since the aqueous solution supplied to the substrate is mixed with the aqueous solutions A and B simultaneously with the supply of the aqueous solution to the substrate, it is necessary for the thin film forming process. The solution can be supplied only to the region, and the effective treatment can be performed without wasting the aqueous solution. In addition, since both aqueous solutions A and B are supplied onto the substrate 20 while being mixed, it is possible to supply an aqueous solution of a stable quality without any unexpected alteration or stagnation of the liquid and without a change in concentration. it can. Therefore, according to the present invention, it is possible to solve the problems of the conventional printing method, vapor deposition, metal wiring pattern manufacturing method by sputtering method, high uniformity of the metal thin film thickness,
It is possible to provide a metal thin film pattern forming apparatus capable of easily and inexpensively forming a pattern image of a highly fine metal thin film with little variation in line width.

[Brief description of the drawings]

FIG. 1 shows a first example of a metal thin film pattern forming apparatus according to the present invention.
It is a schematic diagram showing an embodiment.

FIG. 2 is an enlarged perspective view of a main part showing a back surface of a contact unit in FIG. 1;

FIG. 3 is a schematic view showing a metal thin film pattern forming apparatus according to a second embodiment of the present invention.

FIG. 4 is an enlarged perspective view of a main part showing a back surface of a contact unit in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 13 Metal thin film pattern forming apparatus 10 Mixing system 11 Liquid accommodating area 12 Mixing area 20 Substrate 30 Heating part 32 Heating part 31, 71 Contact means 40 Cleaning part 50 Peeling part 70 Aqueous solution supply system

Claims (6)

[Claims] 1. An aqueous solution mixing system comprising: a storage region for separately storing an aqueous solution containing at least a water-soluble metal compound and an aqueous solution containing a reducing compound; and a mixing region for mixing both aqueous solutions, and a photoresist material. A mixed solution contacting unit that includes a heating unit that heats a substrate having a fine resist pattern formed on the surface of the substrate, and sequentially contacts a mixed aqueous solution supplied from the aqueous solution mixing system to the substrate from a predetermined surface side And a processing tray comprising means. 2. The apparatus according to claim 1, further comprising: a cleaning unit that removes the mixed aqueous solution remaining on the substrate after the processing in the processing tray; and a peeling unit that peels off only the resist pattern portion after the cleaning. 2. The metal thin film pattern forming apparatus according to 1. 3. The mixed liquid contacting means is a member having a length equal to or greater than the width of the substrate, wherein a supply port for supplying the mixed aqueous solution to the substrate faces, and 3. The metal thin film pattern forming apparatus according to claim 1, wherein the apparatus is configured to be movable on the processing tray substantially in parallel. 4. The apparatus according to claim 3, wherein the supply port is formed as a slit. 5. An aqueous solution supply system comprising: a storage area for separately storing an aqueous solution containing at least a water-soluble metal compound and an aqueous solution containing a reducing compound; and a supply pipe for separately supplying both aqueous solutions; A heating unit for heating a substrate having a fine resist pattern formed on the surface thereof using a material is provided, and each aqueous solution supplied from the aqueous solution supply system is sprayed onto the substrate from a predetermined surface side to mix the liquid. A processing tray provided with liquid contact means for sequentially contacting while 6. A cleaning section for removing a mixed aqueous solution remaining on a substrate after processing on the processing tray, and a peeling section for peeling off only the resist pattern section after the cleaning. 6. The metal thin film pattern forming apparatus according to 5.