JP2005213623A - Method for forming film, metal film, electronic parts and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming a film by which a metal film having a predetermined pattern can easily and inexpensively be formed, to provide a metal film formed by the above method, and to provide electronic parts and an electronic apparatus having the metal film. <P>SOLUTION: The method for forming a film includes the steps of: forming a film forming region 9 where a metal film 8 is to be formed on the upper face of a substrate 5 and forming a non-film forming region 9' where no metal film 8 is to be formed, the region 9' having higher liquid repelling property than that of the film forming region 9; supplying a metal 7 to form the metal film 8 while controlling the maximum thickness of the metal to be smaller than the crystal size of the metal 7; and fusing the supplied metal 7 and collecting the metal 7 in a fused state to the film forming region 9 by using the difference between the liquid repelling properties of the film forming region 9 and that of the non-film forming region 9' so as to obtain the metal film 8. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a film forming method, a metal film, an electronic component, and an electronic device.

Conventionally, an etching method using a mask containing a resin as a main component has been widely used for forming a metal film having a predetermined pattern (see, for example, Patent Document 1).
Specifically, I: A layer composed of a film forming material is formed on a substrate. II: A resist material is applied on the layer. III: The resist material is exposed and developed to obtain a resist layer having openings corresponding to unnecessary portions of the layer. IV: Using the resist layer as a mask, the layer exposed in the opening is removed by an etching method. V: The mask is removed. Thereby, a metal film formed in a predetermined pattern is obtained.
However, such a method requires time and labor to form the resist layer. As a result, problems such as a long time required for forming the metal film and an increase in cost occur.

JP-A-5-338184

  An object of the present invention is to provide a film forming method capable of easily and inexpensively forming a metal film having a predetermined pattern, a metal film formed by such a film forming method, an electronic component and an electronic apparatus provided with the metal film. .

Such an object is achieved by the present invention described below.
The film forming method of the present invention is a film forming method for forming a metal film having a predetermined pattern on a substrate,
Formed on the film forming surface of the base material on which the metal film is to be formed are a film forming region for forming the metal film and a non-film forming region that is higher in liquid repellency than the film forming region and does not form the metal film. A first step of:
A second step of supplying a metal for forming the metal film on the film forming surface side of the base material such that the maximum thickness is smaller than the crystal size of the metal;
By melting the supplied metal, and collecting the metal in the molten state in the film formation region using the difference in liquid repellency between the film formation region and the non-film formation region, And obtaining a third step.
Thereby, a metal film can be formed easily and inexpensively with high film forming accuracy.

In the film forming method of the present invention, when the maximum thickness of the supplied metal is X [nm] and the crystal size is Y [nm] in the second step, X / Y ≦ 0.8. It is preferable to satisfy the following relationship.
This more reliably lowers the melting point of the supplied metal, that is, a more remarkable melting point drop occurs.

In the film forming method of the present invention, it is preferable that the metal contains at least one selected from the group consisting of Al, In, Zn, Sn, and Cu as a main component.
When these metals are supplied to the film forming surface side so as to be smaller than the crystal size of the metal, the melting point drop is particularly remarkable.
In the film forming method of the present invention, in the second step, the metal is preferably supplied using a vapor phase film forming method.
According to the vapor phase film forming method, the metal can be accurately supplied to the film forming surface side of the base material so as to have a target thickness.

In the film forming method of the present invention, the vapor phase film forming method is preferably at least one of a sputtering method, a vacuum evaporation method, and an ion plating method.
According to the sputtering method, since the supply amount of the metal to the film forming surface side of the substrate can be controlled more accurately, the metal can be supplied with higher accuracy so as to achieve the target thickness.

  Further, according to the vacuum deposition method and the ion plating method, when the liquid repellent film is formed using the fluorine-based material in the first step, the film formation is performed without damaging the liquid repellent film. Metal can be supplied to the surface side. Thus, in the third step, the metal film can be more reliably formed in the film formation region by utilizing the difference in liquid repellency between the film formation region and the non-film formation region.

In the film forming method of the present invention, in the third step, the melting of the metal is preferably performed by at least one of heating, electromagnetic wave irradiation, and particle beam irradiation.
According to these methods, energy can be uniformly applied to almost the entire surface of the substrate, and the supplied metal can be melted almost simultaneously. As a result, it is possible to prevent the thickness variation from occurring in the obtained metal film.

In the film forming method of the present invention, in the first step, the non-film forming region is a liquid repellent mainly comprising a fluorine-based organic material and / or a fluorine-based inorganic material on the film-forming surface of the substrate. It is preferably obtained by forming a film.
As a result, the liquid repellency of the non-film formation region can be easily and reliably higher than the liquid repellency of the film formation region.

In the film forming method of the present invention, the fluorine-based organic material is polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, ethylene-tetrafluoroethylene copolymer, or perfluoroethylene-propene copolymer. It is preferable that at least one of them is a main component.
Thereby, a liquid repellent film having particularly high liquid repellency and high heat resistance can be formed.

In the film forming method of the present invention, it is preferable that the fluorine-based inorganic material is mainly composed of at least one of potassium fluorotitanate, potassium silicofluoride, and potassium zirconate fluoride.
Thereby, a liquid repellent film having particularly high liquid repellency and high heat resistance can be formed.
In the film forming method of the present invention, in the first step, the contact angle of pure water with respect to the non-film formation region is A [°], and the contact angle of pure water with respect to the film formation region is B [°]. In this case, it is preferable that the relationship A−B ≧ 15 [°] is satisfied.
Thereby, in the third step, the supplied metal is collected in the film formation region with higher selectivity, so that the metal film can be formed with higher film formation accuracy.

The metal film of the present invention is formed by the film forming method of the present invention.
Thereby, a metal film with high film formation accuracy (reliability) can be obtained.
An electronic component according to the present invention includes the metal film according to the present invention.
Thereby, a highly reliable electronic component is obtained.
The electronic device of the present invention includes the electronic component of the present invention.
As a result, a highly reliable electronic device can be obtained.

Hereinafter, a film forming method, a metal film, an electronic component, and an electronic apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
<Film formation method>
First, a preferred embodiment of the film forming method of the present invention will be described.
FIG. 1 is a view (longitudinal sectional view) for explaining the film forming method of the present invention. In the following description, the upper side in FIG. 1 is referred to as “upper” and the lower side is referred to as “lower”.

The film forming method of the present invention is a method of forming a metal film 8 having a predetermined pattern on a base material 5, and as shown in FIG. 1, on the upper surface of the base material 5 (film forming surface for forming the metal film 8). A film forming region forming step for forming a film forming region 9 for forming the metal film 8 and a non-film forming region 9 ′ not forming the metal film 8 having higher liquid repellency than the film forming region 9; A metal supply step for supplying the metal 7 for forming the metal film 8 on the upper surface side so that the maximum thickness thereof is smaller than the crystal size of the metal 7, and melting the supplied metal 7; A metal film forming step of obtaining the metal film 8 by collecting the molten metal in the film forming area 9 by utilizing the difference in liquid repellency between the film forming area 9 and the non-film forming area 9 ′. Hereinafter, each process will be described sequentially.
Here, the crystal size is an average value (average particle size) of crystal grains formed in a bulk metal (obtained by slowly cooling (naturally cooling) a molten metal). Say.

[1] Film formation region formation process First, the base material 5 is prepared (refer Fig.1 (a)).
The constituent material of the base material 5 is not particularly limited as long as it has a melting point higher than the temperature at which the metal 7 melts. For example, various insulating materials (dielectrics) such as quartz glass, silicon dioxide, silicon nitride, Silicon (for example, amorphous silicon, polycrystalline silicon, etc.), indium tin oxide (ITO), indium oxide (IO), tin oxide (SnO ₂ ), antimontin oxide (ATO), indium zinc oxide (IZO), Al, Al The thing comprised by electroconductive materials, such as an alloy, Cr, Mo, Ta, is mentioned, Among these, it can use combining 1 type (s) or 2 or more types.

Next, a film formation region 9 for forming the metal film 8 and a non-film formation region 9 ′ where the metal film 8 having higher liquid repellency than the film formation region 9 is not formed are formed on the upper surface of the substrate 5.
As a method of forming the film forming region 9 and the non-film forming region 9 ′, any method may be used as long as the liquid repellency of the non-film forming region 9 ′ is higher than the liquid repellency of the film forming region 9. Although not particularly limited, a fluorine-based organic material and / or a fluorine-based inorganic material (hereinafter collectively referred to as “ It is preferable to use a method of forming the liquid repellent film 6 whose main material is “fluorine-based material”.

Specifically, a fluorine-based material is supplied to a region where the non-film forming region 9 ′ on the upper surface of the base material 5 is formed to form the liquid repellent film 6 (see FIG. 1B).
By using this method of forming the liquid-repellent film 6 made of a fluorine-based material, the liquid-repellent property of the non-film-forming region 9 ′ can be easily and reliably supplied with the fluorine-based material on the upper surface of the substrate 5 It can be higher than the liquid repellency of the formation region 9. Furthermore, this method has an advantage that the film thickness of the liquid repellent film 6 can be easily controlled.

  Examples of the method for forming the liquid repellent film 6 include various methods such as dip coating, spin coating, slit coating, cap coating, dispenser, spray coating, roll coating, screen printing, and ink jet printing. A coating method can be used, but among these, it is preferable to use an inkjet printing method. According to the ink jet printing method, it is not necessary to form a mask (for example, a resist layer) directly on the substrate 5, and the liquid repellent film 6 can be formed with high accuracy.

In addition, a fluorine-based material having high liquid repellency and high heat resistance is preferable.
Specific examples of such a fluorine-based organic material include, for example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), Examples include perfluoroethylene-propene copolymer (FEP) and ethylene-chlorotrifluoroethylene copolymer (ECTFE). Among these, polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, It is preferable to use at least one of ethylene-tetrafluoroethylene copolymer and perfluoroethylene-propene copolymer as a main component.

On the other hand, specific examples of the fluorine-based inorganic material include, for example, potassium fluoride titanate, potassium silicofluoride, potassium fluoride zirconate, and silicic acid hydrofluoric acid. Among these, potassium fluoride titanate, potassium silicofluoride, etc. And at least one of potassium zirconate fluoride is preferably used as a main component.
By using these fluorine-based materials, a liquid repellent film 6 having particularly high liquid repellency and high heat resistance can be formed. For this reason, in the metal film forming process described later, it is possible to prevent deterioration and deterioration of the liquid repellent film 6 even under high temperature conditions, and to prevent liquid repellency from being impaired. As a result, the difference in liquid repellency between the film forming region 9 and the non-film forming region 9 ′ is maintained (maintained), and the metal film 8 can be more reliably formed.

  The difference in the degree of liquid repellency between the film forming region 9 and the non-film forming region 9 ′ can be expressed by various indicators, but can be preferably expressed by using, for example, a contact angle. Specifically, when the contact angle of pure water with respect to the non-film formation region 9 ′ is A [°] and the contact angle of pure water with respect to the film formation region 9 is B [°], A−B ≧ 15 [° It is preferable to satisfy the following relationship: more preferable to satisfy the relationship of AB ≧ 30 [°], and particularly preferable to satisfy the relationship of AB ≧ 50 [°]. When the film forming region 9 and the non-film forming region 9 ′ satisfy the above relationship, the metal 7 supplied to the upper surface side of the substrate 5 is more highly selective in the metal film forming step described later. The metal film 8 can be formed with higher deposition accuracy by gathering in the film formation region 9 of the material 5.

  In the present embodiment, a case where a liquid repellent film composed of a material (fluorine-based material) higher than the liquid repellency of the film forming area 9 is formed in the non-film forming area 9 ′ on the upper surface of the substrate 5 will be described. However, the present invention is not limited to this. For example, the liquid repellent property of the film forming region 9 is formed by forming a liquid repellent film on almost the entire upper surface of the substrate 5 and irradiating the film forming region 9 with active energy rays. The liquid repellency of the non-film formation region 9 ′ may be made higher than the liquid repellency of the film formation region 9 by performing a process of reducing the above. Depending on the type of the substrate 5, the non-film-forming region 9 'may be formed using a coupling agent having a functional group containing fluorine.

[2] Metal supply step Next, the metal film 8 is formed on the upper surface side of the substrate 5 (in this embodiment, so as to cover almost all of the film formation region 9 and the non-film formation region 9 ′). The metal 7 is supplied such that its maximum thickness is smaller than the crystal size of the metal 7.
Thereby, the metal 7 is solidified in a non-crystallized state (non-crystalline state). As a result, the melting point of the metal 7 is lower than the melting point of the metal 7 in the crystalline state (decrease in melting point). For this reason, the metal 7 can be melted at a relatively low temperature in the metal film forming step described later.

  Examples of the metal 7 include Al, In, Zn, Sn, Cu, Ni, Pd, Pt, Li, Mg, Ca, Sr, La, Ce, Er, Eu, Sc, Y, Yb, Ag, Co, Metals such as Cs and Rb, alloys containing these, and the like can be used. Among these, at least one selected from the group consisting of Al, In, Zn, Sn, and Cu is used as a main component. preferable. In these cases, the melting point drop as described above occurs more remarkably. Moreover, since it is excellent in electroconductivity, it can be suitably applied to wiring of various electronic components.

The method for supplying the metal 7 is not particularly limited, but it is preferable to use a vapor deposition method. Thereby, the metal 7 can be accurately supplied to the upper surface side of the base material 5 so as to have a target thickness.
Examples of the vapor deposition method include physical vapor deposition methods such as sputtering, vacuum deposition, ion plating, and laser ablation, and thermal CVD, photo CVD, and laser CVD. A chemical vapor deposition method such as a method can be used, but among these, it is more preferable to use at least one of a sputtering method, a vacuum deposition method, and an ion plating method.

According to the sputtering method, since the supply amount of the metal 7 to the upper surface side of the base material 5 can be controlled more accurately, the metal 7 can be supplied more accurately so as to achieve the target thickness. Thereby, the metal 7 can be supplied to the upper surface side of the base material 5 with a more accurate thickness, and the maximum thickness of the metal 7 can be made smaller than the maximum length of the crystal axis.
According to the vacuum deposition method and the ion plating method, when the liquid repellent film 6 is formed using a fluorine-based material in the film formation region forming step, the liquid repellent film 6 is not damaged. Metal 7 can be supplied to the upper surface of the material 5. Accordingly, the metal film 8 can be more reliably formed in the film formation region 9 by utilizing the difference in liquid repellency between the film formation region 9 and the non-film formation region 9 ′ in the metal film formation step described later. it can.
Hereinafter, as a method for supplying the metal 7, a case where a sputtering method and a vacuum evaporation method are used will be described as a representative.

[2a] Metal supply step by sputtering method When the sputtering method is used as the metal 7 supply method, the base material 5 in which the film formation region 9 and the non-film formation region 9 ′ are formed in the chamber, and the metal 7 In a state in which the metal materials constituting each are installed (set), the metal material is irradiated with an ion beam. Thereby, the ion beam collides with the surface of the metal material, the metal material particles (sputtered particles) are knocked out, and the metal 7 is supplied by being deposited on the upper surface side of the substrate 5 (FIG. 1C). )reference).

The acceleration voltage of the ion beam is preferably 50 V or more, and more preferably about 50 to 700 V.
The ion beam current is preferably about 50 to 500 mA, and preferably about 100 to 200 mA.
The pressure in the atmosphere (inside the chamber) for irradiating the ion beam is preferably as low as possible and is not particularly limited, but is preferably about 1 × 10 ⁻⁵ to 1 × 10 ⁻¹ Torr, and 1 × 10 ^−4. More preferably, it is about ˜1 × 10 ⁻² Torr.
Irradiation time of the ion beam, but is preferably in the range of about 1 × ¹⁰ -4 ~1sec, and more preferably 1 × ¹⁰ -4 ~1 × ¹⁰ -1 approximately sec.
As ions constituting the ion beam, ions of various rare gases can be used, but those mainly composed of at least one of Ar ⁺ , Kr ⁺ and Xe ⁺ are preferable.

[2b] Metal supply step by vacuum evaporation method When using the vacuum evaporation method as the supply method of the metal 7, the base material 5 in which the film formation region 9 and the non-film formation region 9 ′ are formed in the chamber; In a state where the metal materials constituting the metal 7 are respectively installed (set), the metal materials are heated. As a result, the metal material evaporates (vaporizes), and is deposited (evaporated) on the upper surface side of the base material 5 to supply the metal 7 (see FIG. 1C).

The pressure in the atmosphere (inside the chamber) for irradiating the ion beam is preferably as low as possible and is not particularly limited, but is preferably about 1 × 10 ⁻⁵ to 1 × 10 ⁻¹ Torr, and 1 × 10 ^−4. More preferably, it is about ˜1 × 10 ⁻² Torr.
The heating means for heating the metal material is not particularly limited, and for example, resistance heating or electron beam heating can be used.

  The maximum thickness of the supplied metal 7 may be any thickness as long as it is thinner than the crystal size of the metal 7, but the maximum thickness of the metal 7 is X [nm], and the crystal size Is preferably Y [nm], preferably satisfies the relationship X / Y ≦ 0.8, more preferably satisfies the relationship X / Y ≦ 0.5, and X / Y ≦ 0.1. More preferably, the relationship is satisfied. By satisfying such a relationship, the melting point of the supplied metal 7 is more reliably lowered, that is, a more remarkable melting point drop occurs. Thereby, in the metal film formation process mentioned later, since the temperature which fuse | melts the metal 7 can be made low, the quality change and deterioration of the base material 5 and the liquid-repellent film 6 can be prevented suitably. As a result, the difference in liquid repellency between the film forming region 9 and the non-film forming region 9 ′ is maintained (maintained), and the metal film 8 can be more reliably formed in the film forming region 9 of the base material 5.

[3] Metal Film Forming Step Next, the supplied metal 7 is melted, and the molten metal 7 is made into a film by utilizing the difference in liquid repellency between the film forming region 9 and the non-film forming region 9 ′. Collect in forming area 9. Thereby, the metal film 8 is obtained.
Specifically, energy is applied to the metal 7 to melt it. Due to the difference in liquid repellency between the film forming region 9 and the non-film forming region 9 ′, the molten metal 7 changes from the non-film forming region 9 ′ having high liquid repellency to the film forming region 9 having low liquid repellency. Collect (aggregate) (see FIG. 1 (d)). A metal film 8 is formed by the aggregation of the metal 7 (see FIG. 1E).

At this time, if the metal film 8 does not solidify, a treatment for solidifying the metal film 8 may be performed as necessary.
The method for melting the metal 7 (melting method) may be any method, but in particular, it is preferably performed by at least one of heating, electromagnetic wave irradiation, and particle beam irradiation. According to these methods, energy can be uniformly applied to almost the entire surface of the substrate 5, and the metal 7 can be melted almost simultaneously. As a result, it is possible to prevent thickness variations from occurring in the metal film 8.

I: When the metal 7 is melted by heating As the method for heating the metal 7, various methods can be used. For example, the metal 7 can be heated using an electric heater.
The time for heating the metal 7 is preferably about 0.1 to 30 minutes, and more preferably about 1 to 15 minutes.

The heating atmosphere at this time is preferably a reducing atmosphere, an inert atmosphere, a non-oxidizing atmosphere such as a vacuum or under reduced pressure.
The temperature of the heating atmosphere is preferably about 0 to 100 ° C, more preferably about 20 to 50 ° C.
By setting the heating time, the heating atmosphere, and the temperature of the heating atmosphere within the above ranges, the metal film 8 can be more reliably formed in the film forming region 9.

II: When melting the metal 7 by irradiation with electromagnetic waves Examples of the electromagnetic waves to be irradiated include microwaves, infrared rays, visible rays, ultraviolet rays, and X-rays.
For example, when a microwave is used as the electromagnetic wave, the frequency of the irradiated microwave is preferably about 3 × 10 ⁸ to 1 × 10 ¹¹ Hz, and is about 1 × 10 ⁹ to 1 × 10 ¹⁰ Hz. Is more preferable.

The irradiation intensity of the microwave is preferably about 10 to 1000 W, and more preferably about 100 to 500 W.
The microwave irradiation time is preferably about 0.1 to 30 minutes, and more preferably about 1 to 15 minutes.
The heating atmosphere at this time is preferably a reducing atmosphere, an inert atmosphere, a non-oxidizing atmosphere such as a vacuum or under reduced pressure.

Next, the temperature of the irradiation atmosphere is preferably about 0 to 100 ° C, more preferably about 20 to 50 ° C.
By setting the microwave frequency, irradiation intensity, irradiation time, irradiation atmosphere, and temperature of the irradiation atmosphere within the above ranges, the metal film 8 can be more reliably formed in the film formation region 9.

III: When melting the metal 7 by irradiation with a particle beam Examples of the particle beam to be irradiated include an electron beam, an ion beam, a neutron beam and an α-ray.
For example, when an ion beam is used as the particle beam, the acceleration voltage of the irradiated ion beam is preferably about 1 to 150 kV, more preferably about 10 to 50 kV.

The beam current of the ion beam is preferably about 0.01 to 50 nA, and more preferably about 0.01 to 20 nA.
The irradiation time of the ion beam is preferably about 0.001 to 50 seconds, and more preferably about 0.001 to 50 seconds.
The heating atmosphere at this time is preferably a reducing atmosphere, an inert atmosphere, a non-oxidizing atmosphere such as a vacuum or under reduced pressure.

Next, the temperature of the irradiation atmosphere is preferably 0 to 100 ° C, and more preferably 20 to 50 ° C.
By setting the ion beam acceleration voltage, beam current, irradiation time, irradiation atmosphere, and irradiation atmosphere temperature within the above ranges, the metal film 8 can be more reliably formed in the film formation region 9.
The metal film 8 is obtained through the above processes.

According to the present invention, it is not necessary to directly form a mask (for example, a resist layer) on the base material, and the metal film 8 can be formed with high film forming accuracy.
In addition, according to the present invention, since a resist layer is not used, a complicated process for forming a resist layer and a process for removing a resist layer that has become unnecessary can be omitted.
Therefore, according to the present invention, the metal film 8 can be obtained more easily and inexpensively with high film forming accuracy.
In addition, according to the present invention, the metal film 8 can be selectively formed in the film formation region 9, that is, the formation of the metal film 8 in an unnecessary region is prevented, so that the amount of metal material used can be reduced. You can also plan.

<Electronic parts>
Such a metal film 8 can be applied to various electronic components such as switching elements (thin film transistors), wiring boards, semiconductor components, display panels, and light emitting elements.
Below, the case where the electronic component of this invention is applied to a thin-film transistor (especially organic thin-film transistor) is demonstrated as a representative.

FIG. 2A is a longitudinal sectional view showing an embodiment of a thin film transistor to which the electronic component of the present invention is applied. In the following description, the upper side in FIG. 2 will be described as “upper” and the lower side as “lower”.
A thin film transistor 100 shown in FIG. 2A is provided on a substrate 20 (base material 5), and includes a source electrode 30 and a drain electrode 40, an organic semiconductor layer (organic layer) 50, a gate insulating layer 60, The gate electrode 70 is laminated in this order from the substrate 20 side.

  Specifically, in the thin film transistor 100, the source electrode 30 and the drain electrode 40 are provided separately on the substrate 20, and the organic semiconductor layer 50 is provided so as to cover the electrodes 30 and 40. Further, a gate insulating layer 60 is provided on the organic semiconductor layer 50, and a gate electrode 70 is further provided thereon so as to overlap at least a region between the source electrode 30 and the drain electrode 40.

In the thin film transistor 100, a region between the source electrode 30 and the drain electrode 40 in the organic semiconductor layer 50 is a channel region 510 in which carriers move. Hereinafter, in this channel region 510, the length in the direction of carrier movement, that is, the distance between the source electrode 30 and the drain electrode 40 is the channel length L, and the length perpendicular to the channel length L direction is the channel width W. say.
Such a thin film transistor 100 is a thin film transistor having a structure in which the source electrode 30 and the drain electrode 40 are provided closer to the substrate 20 than the gate electrode 70 with the gate insulating layer 60 interposed therebetween, that is, a thin film transistor having a top gate structure.

Hereinafter, each part which comprises the thin-film transistor 100 is demonstrated sequentially.
The substrate 20 supports each layer (each part) constituting the thin film transistor 100. Examples of the substrate 20 include a plastic substrate (resin substrate) made of, for example, a glass substrate, polyimide, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), aromatic polyester (liquid crystal polymer), and the like. A quartz substrate, a silicon substrate, a gallium arsenide substrate, or the like can be used. When the thin film transistor 100 is provided with flexibility, a resin substrate is selected as the substrate 20.

An underlayer may be provided on the substrate 20. The underlayer is provided, for example, for the purpose of preventing diffusion of ions from the surface of the substrate 20 or for the purpose of improving the adhesion (bondability) between the source electrode 30 and the drain electrode 40 and the substrate 20.
The constituent material of the underlayer is not particularly limited, but when a glass substrate is used as the substrate 20, silicon oxide (SiO ₂ ), silicon nitride (SiN), or the like is preferably used.

On the substrate 20, a source electrode 30 and a drain electrode 40 are juxtaposed at a predetermined distance along the channel length L direction.
The metal film 8 of the present invention can be applied to the source electrode 30 and the drain electrode 40.
The thickness (average) of the source electrode 30 and the drain electrode 40 is not particularly limited, but is preferably about 30 to 300 nm, and more preferably about 50 to 150 nm. According to the film forming method of the present invention, an electrode having such a thin film thickness can be formed with high dimensional accuracy.

  The distance (separation distance) between the source electrode 30 and the drain electrode 40, that is, the channel length L is preferably about 2 to 30 μm, and more preferably about 5 to 20 μm. If the channel length L is smaller than the lower limit value, an error occurs in the channel length between the obtained thin film transistors 100, and the characteristics (transistor characteristics) may vary. On the other hand, when the channel length L is larger than the upper limit value, the absolute value of the threshold voltage is increased, the drain current value is decreased, and the characteristics of the thin film transistor 100 may be insufficient.

  The channel width W is preferably about 0.1 to 5 mm, and more preferably about 0.5 to 3 mm. When the channel width W is made smaller than the lower limit value, the drain current value becomes small, and the characteristics of the thin film transistor 100 may be insufficient. On the other hand, when the channel width W is larger than the upper limit value, the thin film transistor 100 is increased in size, and there is a possibility that parasitic capacitance increases and leakage current to the gate electrode 70 via the gate insulating layer 60 increases.

An organic semiconductor layer 50 is provided on the substrate 20 so as to cover the source electrode 30 and the drain electrode 40.
The organic semiconductor layer 50 is composed mainly of an organic semiconductor material (an organic material that exhibits semiconducting electrical conduction).
The organic semiconductor layer 50 is preferably oriented so as to be substantially parallel to the channel length L direction at least in the channel region 510. As a result, the carrier mobility in the channel region 51 is high, and as a result, the thin film transistor 100 has a higher operating speed.

  Examples of the organic semiconductor material include naphthalene, anthracene, tetracene, pentacene, hexacene, phthalocyanine, perylene, hydrazone, triphenylmethane, diphenylmethane, stilbene, arylvinyl, pyrazoline, triphenylamine, triarylamine, oligothiophene, phthalocyanine or Low molecular organic semiconductor materials such as these derivatives, poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polythiophene, polyhexylthiophene, poly (p-phenylenevinylene), polytinylenevinylene, polyarylamine, Pyreneformaldehyde resin, ethylcarbazole formaldehyde resin, fluorene-bithiophene copolymer, fluorene-arylamine copolymer or Examples thereof include polymeric organic semiconductor materials (conjugated polymer materials) such as derivatives, and one or more of these can be used in combination. It is preferable to use a material mainly composed of (conjugated polymer material). The conjugated polymer material has a particularly high carrier mobility due to its unique electron cloud spread.

  A polymer organic semiconductor material can be formed by a simple method and can be oriented relatively easily. Of these, fluorene-bithiophene copolymers, polyarylamines or these are used as high molecular organic semiconductor materials (conjugated polymer materials) because they are difficult to oxidize in air and are stable. It is particularly preferable to use a derivative containing at least one of the derivatives as a main component.

In addition, the organic semiconductor layer 50 composed mainly of a polymer organic semiconductor material can be reduced in thickness and weight, and has excellent flexibility. Therefore, the thin film transistor can be used as a switching element of a flexible display. Suitable for applications.
The thickness (average) of the organic semiconductor layer 50 is preferably about 0.1 to 1000 nm, more preferably about 1 to 500 nm, and further preferably about 10 to 100 nm.

Note that the organic semiconductor layer 50 is not limited to a structure provided so as to cover the source electrode 30 and the drain electrode 40, and is provided at least in a region (channel region 510) between the source electrode 30 and the drain electrode 40. It only has to be.
A gate insulating layer 60 is provided on the organic semiconductor layer 50.
The gate insulating layer 60 insulates the gate electrode 70 from the source electrode 30 and the drain electrode 40.

The gate insulating layer 60 is preferably mainly composed of an organic material (particularly an organic polymer material). The gate insulating layer 60 containing an organic polymer material as a main material can be easily formed and can improve the adhesion to the organic semiconductor layer 50.
Examples of such organic polymer materials include polystyrene, polyimide, polyamideimide, polyvinylphenylene, polycarbonate (PC), acrylic resin such as polymethyl methacrylate (PMMA), and polytetrafluoroethylene (PTFE). Fluorine resin, phenolic resin such as polyvinylphenol or novolac resin, and olefinic resins such as polyethylene, polypropylene, polyisobutylene, polybutene, etc. are used, and one or more of these may be used in combination. it can.

  The thickness (average) of the gate insulating layer 60 is not particularly limited, but is preferably about 10 to 5000 nm, and more preferably about 100 to 1000 nm. By setting the thickness of the gate insulating layer 60 within the above range, the thin film transistor 100 is increased in size while the source electrode 30 and the drain electrode 40 are reliably insulated from the gate electrode 70 (in particular, the thickness is increased). ) Can be prevented.

Note that the gate insulating layer 60 is not limited to a single-layer structure, and may have a multilayer structure.
In addition, as a constituent material of the gate insulating layer 60, for example, an inorganic insulating material such as SiO ₂ can be used. By applying a solution such as polysilicate, polysiloxane, or polysilazane and heating the coating film in the presence of oxygen or water vapor, SiO ₂ can be obtained from the solution material. In addition, after applying a metal alkoxide solution, an inorganic insulating material can be obtained (known as a sol-gel method) by heating it in an oxygen atmosphere.

A gate electrode 70 is provided on the gate insulating layer 60.
Examples of the constituent material of the gate electrode 70 include metal materials such as Pd, Pt, Au, W, Ta, Mo, Al, Cr, Ti, Cu or alloys containing these, ITO, FTO, ATO, SnO _{2, and the} like. Carbon materials such as conductive oxide, carbon black, carbon nanotube, fullerene, polyacetylene, polypyrrole, polythiophene such as PEDOT (poly-ethylenedioxythiophene), polyaniline, poly (p-phenylene), poly (p-phenylene vinylene), poly Examples include conductive polymer materials such as fluorene, polycarbazole, polysilane, or derivatives thereof, and are usually doped with polymers such as iron chloride, iodine, inorganic acid, organic acid, and polystyrene sulfonic acid to impart conductivity. Used in the state. Further, one or more of these can be used in combination.

The thickness (average) of the gate electrode 70 is not particularly limited, but is preferably about 0.1 to 5000 nm, more preferably about 1 to 5000 nm, and still more preferably about 10 to 5000 nm.
In the thin film transistor 100 as described above, the amount of current flowing between the source electrode 30 and the drain electrode 40 is controlled by changing the voltage applied to the gate electrode 70.

  That is, in the OFF state in which no voltage is applied to the gate electrode 70, even if a voltage is applied between the source electrode 30 and the drain electrode 40, almost no carriers are present in the organic semiconductor layer 50, so that a very small current Only flows. On the other hand, in the ON state in which a voltage is applied to the gate electrode 70, charges are induced in the portion of the organic semiconductor layer 50 facing the gate insulating layer 60, and a carrier flow path is formed in the channel region 510. When a voltage is applied between the source electrode 30 and the drain electrode 40 in this state, a current flows through the channel region 510.

<Electronic equipment>
The electronic component of the present invention can be used for various electronic devices.
FIG. 3 is a perspective view showing the configuration of a mobile (or notebook) personal computer to which the electronic apparatus of the present invention is applied.
In this figure, a personal computer 1100 includes a main body 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display. The display unit 1106 is rotatable with respect to the main body 1104 via a hinge structure. It is supported by.

The electronic component of the present invention is incorporated as, for example, a switching element for switching each pixel of the display portion, a flexible wiring board for connecting the main body portion 1104 and the display unit 1106, or the like.
FIG. 4 is a perspective view showing a configuration of a mobile phone (including PHS) to which the electronic apparatus of the present invention is applied.

In this figure, a cellular phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204 and a mouthpiece 1206, and a display unit.
The electronic component of the present invention is incorporated as, for example, a switching element for switching each pixel of the display unit, a semiconductor component (various memories) for storing data, a circuit board, and the like.
FIG. 5 is a perspective view showing a configuration of a digital still camera to which the electronic apparatus of the present invention is applied. In this figure, connection with an external device is also simply shown.

Here, an ordinary camera sensitizes a silver halide photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an imaging device such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.
A display unit is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to display based on an imaging signal from the CCD, and functions as a finder that displays an object as an electronic image.

A circuit board 1308 is installed inside the case. The circuit board 1308 is provided with a memory that can store (store) an imaging signal.
A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side of the case 1302 (on the back side in the illustrated configuration).
When the photographer confirms the subject image displayed on the display unit and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory of the circuit board 1308.

  In the digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the data communication input / output terminal 1314 as necessary. Further, the imaging signal stored in the memory of the circuit board 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation.

The electronic component of the present invention is incorporated as, for example, a switching element for switching each pixel of the display unit, a semiconductor component (various memories) for storing a CCD imaging signal, a circuit board 1308, and the like.
The electronic apparatus of the present invention includes, for example, a television, a video camera, a viewfinder type, in addition to the personal computer (mobile personal computer) in FIG. 3, the mobile phone in FIG. 4, and the digital still camera in FIG. Monitor direct-view video tape recorder, laptop personal computer, car navigation system, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game device, word processor, workstation, video phone, security TV Monitors, electronic binoculars, POS terminals, devices equipped with touch panels (for example, cash dispensers and automatic ticket vending machines for financial institutions), medical devices (for example, electronic thermometers, blood pressure monitors, blood glucose meters, electrocardiographs, ultrasound diagnostic devices, internal Endoscope display device), fish finder, various measuring instruments, Vessels such (e.g., gages for vehicles, aircraft, and ships), a flight simulator, various monitors, and a projection display such as a projector.
As mentioned above, although the film-forming method, metal film, electronic component, and electronic device of this invention were demonstrated based on embodiment of illustration, this invention is not limited to these.

Next, specific examples of the present invention will be described.
(Example 1)
<1> First, a quartz glass substrate (base material) was prepared and washed with pure water.
Next, an ink containing PTFE (coating liquid) is applied onto the quartz glass substrate by an inkjet printing method in a region (non-film forming region) other than the metal film forming region, and then at 80 ° C. for 30 minutes. A liquid repellent film was formed by drying. Then, it washed sequentially with pure water and ethanol.

The ink was prepared by dissolving the PTFE in a mixed solvent of methyl ethyl ketone and toluene.
As a result, a non-film forming region where the liquid repellent film was formed and a film forming region where the surface of the quartz glass substrate was exposed were partitioned.
The planar shape of the film formation region was the capital letter “E” of the alphabet, and each part was formed to have a width of about 60 μm.
Further, the relationship AB between the contact angle A [°] of pure water to the non-film formation region (liquid repellent film) and the contact angle B [°] of pure water to the film formation region (quartz glass substrate surface) is: It was 40 [°].

<2> Next, a quartz glass substrate on which a liquid repellent film is formed and a target made of Al (metal film material) are respectively set (set) in the chamber, and this quartz glass is formed by a sputtering method. Al was supplied onto the substrate so that the maximum thickness was 100 nm. Then, it wash | cleaned one by one with water and ethanol.
The relationship X / Y between the maximum thickness X [nm] of the supplied Al and the crystal size Y [nm] of Al was 0.01.
The sputtering conditions were: Ar was discharged, the pressure in the chamber was 1 × 10 ⁻² Torr, and the discharge time was 1 min.

<3> Next, Al supplied on the quartz glass substrate was heated at a heating temperature of 350 ° C. using an electric heater. The atmospheric pressure was 760 Torr, and the heating time was 1 min. The atmosphere was N ₂ atmosphere.
As a result, Al collects and solidifies (hardens) in the film formation region, and an Al film (average thickness: about 150 nm, width of each part: about 60 μm) substantially corresponding to the shape “E” of the film formation region is obtained. It was.

(Example 2)
A metal film was formed in the same manner as in Example 1 except that the following changes were made.
In was used as the metal film material.
In the step <2>, the maximum thickness of In was supplied onto a quartz glass substrate by using a vacuum deposition method so that the maximum thickness of In was 100 nm.

In step <3>, the heating temperature was 100 ° C., the atmospheric pressure was 760 Torr, and the heating time was 1 min. The atmosphere was N ₂ atmosphere.
The relationship X / Y between the maximum thickness X [nm] of the supplied In and the crystal size Y [nm] of In was 0.02.
Thus, an In film (average thickness: about 150 nm, width of each part: about 60 μm) having a shape substantially corresponding to the shape “E” of the film formation region was obtained.

(Example 3)
A metal film was formed in the same manner as in Example 1 except that the liquid repellent film was formed using potassium silicofluoride instead of PTFE.
The relationship X / Y between the maximum thickness X [nm] of the supplied Al and the crystal size Y [nm] of Al was 0.01.
As a result, an Al film (average thickness: about 150 nm, width of each part: about 60 μm) having a shape substantially corresponding to the shape “E” of the film formation region was obtained.

In any of the examples, no metal film was formed in the non-film formation region.
Further, in place of PTFE and potassium silicofluoride, a liquid repellent film is formed using PFA, ETFE, FEP, potassium fluorotitanate and potassium zirconate fluoride, or any two or more of these. Then, metal films (Al film and In film) were formed in the same manner as in Examples 1 and 2, both of which were the same as in Examples 1 and 2.

It is sectional drawing which shows suitable embodiment of the film-forming method of this invention. It is a figure which shows embodiment of the thin-film transistor to which the electronic component of this invention is applied, (a) is a longitudinal cross-sectional view, (b) is a top view. 1 is a perspective view showing a configuration of a mobile (or notebook) personal computer to which an electronic apparatus of the present invention is applied. It is a perspective view which shows the structure of the mobile telephone (PHS is also included) to which the electronic device of this invention is applied. It is a perspective view which shows the structure of the digital still camera to which the electronic device of this invention is applied.

Explanation of symbols

  5 ... Base material 6 ... Liquid repellent film 7 ... Metal 8 ... Metal film 9 ... Film formation region 9 '... Non-film formation region 100 ... Thin film transistor 20 ... Substrate 30 ... Source electrode 40 ... Drain electrode 50... Organic semiconductor layer 510... Channel region 60... Gate insulating layer 70... Gate electrode 1100. ... Operation buttons 1204 ...... Ejection mouth 1206 ...... Transmission mouth 1300 ... Digital still camera 1302 ... Case (body) 1304 ... Light receiving unit 1306 ... Shutter button 1308 ... Circuit board 1312 ... Video signal output terminal 1314 Input / output terminal for data communication 1430 Levi Monitor 1440 Personal Computer

Claims (13)

A film forming method for forming a metal film having a predetermined pattern on a substrate,
Formed on the film forming surface of the base material on which the metal film is to be formed are a film forming region for forming the metal film and a non-film forming region that is higher in liquid repellency than the film forming region and does not form the metal film. A first step of:
A second step of supplying a metal for forming the metal film on the film forming surface side of the base material such that the maximum thickness is smaller than the crystal size of the metal;
By melting the supplied metal, and collecting the metal in the molten state in the film formation region using the difference in liquid repellency between the film formation region and the non-film formation region, And a third step of obtaining a film forming method.   2. The relation of X / Y ≦ 0.8 is satisfied when the maximum thickness of the supplied metal is X [nm] and the crystal size is Y [nm] in the second step. 2. The film forming method described in 1.   The film forming method according to claim 1, wherein the metal contains at least one selected from the group consisting of Al, In, Zn, Sn, and Cu as a main component.   The film forming method according to claim 1, wherein, in the second step, the metal is supplied using a vapor phase film forming method.   The film forming method according to claim 4, wherein the vapor phase film forming method is at least one of a sputtering method, a vacuum evaporation method, and an ion plating method.   The film forming method according to claim 1, wherein in the third step, the melting of the metal is performed by at least one of heating, electromagnetic wave irradiation, and particle beam irradiation.   In the first step, the non-film formation region is obtained by forming a liquid repellent film mainly composed of a fluorine-based organic material and / or a fluorine-based inorganic material on the film-forming surface of the base material. The film forming method according to claim 1.   The fluorine-based organic material is mainly composed of at least one of polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, ethylene-tetrafluoroethylene copolymer and perfluoroethylene-propene copolymer. The film forming method according to claim 7.   The film forming method according to claim 7, wherein the fluorine-based inorganic material contains at least one of potassium fluorotitanate, potassium silicofluoride, and potassium fluorozirconate as a main component.   In the first step, when the contact angle of pure water with respect to the non-film formation region is A [°] and the contact angle of pure water with respect to the film formation region is B [°], A−B ≧ 15 [ The film forming method according to claim 1, wherein the relationship:   A metal film formed by the film forming method according to claim 1.   An electronic component comprising the metal film according to claim 11.   An electronic device comprising the electronic component according to claim 12.

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