JPH11274681A - Electronic device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture various types of electronic devices also by the printing method, by forming on a substrate an absorption layer having an absorbing power to a solvent for an ink contg. a material for forming element patterns of the electronic device. SOLUTION: To form an Si monoxide adsorption layer 13 on a substrate, Si dioxide is dispersed in a polar solvent to prepare a soln., it is coated on the entire substrate surface and dried over 150 deg.C to deposit Si dioxide as an adsorption layer 13 on the substrate, and an Ni-contg. ink soln. is jetted on the adsorption layer 13 by the ink jet method to form a pattern of gate electrodes 14, such that the solvent 30 in the ink is adsorbed in the adsorption layer 13, Ni in the ink is left on the adsorption layer 13, and the pattern of the gate electrodes 14 is accurately written on the substrate to quickly diffusing the solvent 30 in the adsorption layer 13 in this step.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device, and more particularly, to an electronic device in which element patterns such as electrodes and insulating films constituting the electronic device are formed on a substrate by a printing method. The invention further relates to a method for manufacturing this potential device.

[0002]

2. Description of the Related Art As a method of forming an element pattern of an electronic device on a substrate, a conductive film, an insulating film, a semiconductor film, a dielectric film, etc. are formed on the entire surface by a vacuum process such as sputtering or vapor deposition. Generally, patterning is performed into an element shape by a photolithography technique. The photolithography technique is a method in which a photosensitive resist is applied on a thin film to be patterned, exposed and developed through a photomask, and then the exposed thin film portion is dry-etched or wet-etched. Usually, after that, the photolithography process is repeated after removing the resist and forming a further material.

Recently, a method has been attempted in which an ink-jet printer head is applied without using photolithography to directly pattern a material made into ink.

[0004] As a conventional example related to this technology, for example, Japanese Patent Application Laid-Open No. 8-327816 discloses that each frame on a light-transmitting substrate on which a number of frames for partitioning a number of filter elements are formed. There has been proposed a method of manufacturing a color filter for manufacturing each filter by discharging ink colored in a predetermined color.

[0005] This method has an advantage that a resist is not required and a material can be efficiently made into an element. In order to store the ink in a desired position, a method of providing a frame on a substrate or providing a gelatin or acrylic adsorption layer for fixing a dye in the ink has been studied. After the ink is ejected, the ink is uniformly diffused, and the solvent and the solvent in the ink are removed to obtain a patterned thin film.

[0006]

In the above-mentioned conventional example using an ink jet head, the ink spreads on the substrate. A fine pattern cannot be formed. That is, the ink cannot be uniformly formed at a desired position on the substrate. In addition, the technique of creating a large number of frames for partitioning a large number of filter elements requires a new photo-etching step for creating such a frame. Further, even if an attempt is made to print inks of different materials in different patterns, the technique using a frame cannot be used.

On the other hand, in the method of forming a solvent layer of gelatin or the like, and diffusing and fixing the ink, it is not possible to stack thin films indispensable for the element structure of an electronic device, and there is a problem that ink materials are mixed. In general, semiconductors and insulating films required for electronic devices are subjected to post-treatment such as heating after film formation. Organic porous films such as gelatin and acryl suitable for fixing ink have a problem that heat resistance is low and the function of the thin film becomes insufficient.

[0008] Therefore, a main object of the present invention is to provide a printing technique applicable to electronic devices in general. Another object of the present invention is to provide an electronic device manufactured by this technique. Another object of the present invention is to provide this electronic device in which a fine pattern is formed. Yet another object is to provide this electronic device that allows for heat treatment. Still another object is to provide a method for manufacturing the electronic device.

[0009]

According to the present invention, an adsorbing layer having an adsorbing ability for a solvent of an ink containing a material for forming an element pattern of an electronic device is formed on a substrate. Things. According to the present invention, since the solvent in the ink is adsorbed, permeated, or absorbed in the adsorption layer, the element pattern material, which is a solute component in the ink, is laminated on the adsorption layer without spreading the ink.

[0010]

The preferred form of the adsorption layer is an inorganic porous material. As the inorganic porous body, one obtained by depositing inorganic oxide fine particles on a substrate is suitably used. For example, the oxide fine particles may be dispersed in a polar solvent such as water or alcohol and applied to the entire surface of the substrate, or may be applied in a desired pattern. The former is performed using a coater or the like, and the latter is performed by screen printing, an ink jet method using an ink jet head, or an ink jet method (a bubble jet method in which an ink liquid is ejected by pressure increase caused by bubbles generated by increasing the ink temperature). Jet method).

When the substrate is placed under heating, the solvent evaporates from the solution containing the oxide fine particles, and the porous inorganic oxide layer is fixed on the substrate. Examples of oxides usable in the present invention include, for example, SiO ₂ , Al ₂ O ₃ , TiO ₂ ,
At least one of the group consisting of metal oxides of ZrO ₂ is preferred.

It is preferable that the diameter of the porous material made of the oxide is smaller than the particle size of the solute (material constituting the electrode and the insulating film) in the ink. By doing so, the solute in the ink does not enter the inorganic porous material, and the solute is deposited on the oxide film to form an element pattern such as a functional film such as an electrode or an insulating film. As such a pore size, 1 micron or less, preferably 0.1 micron or less, 0.00
1 micron or more. If the pore diameter is less than 0.001 micron, the solvent in the ink is not sufficient to diffuse, permeate or adsorb to the oxide film. The oxide fine particles preferably have a particle size of 10 microns or less. This is for forming a dense oxide deposited film on the substrate. The thickness of the deposited film of oxide fine particles is preferably 10 μm to 100 μm, but is not particularly limited. This oxide film functions as a low dielectric constant insulating film.

By forming the adsorption layer from a film composed of an inorganic oxide layer, the heat resistance is improved as compared with the case where the adsorption layer is formed from a resin as described above. In the electronic device of the present invention, by using a heat-resistant substrate as the substrate, heat resistance of 300 ° C. or more, more preferably 500 ° C. or more, which can withstand thermal annealing and laser annealing is obtained.
Accordingly, a TFT (thin film transistor), a TFD (thin film diode), a RAM, a radio wave responsive sheet in which a coil and a capacitor are formed on a substrate, and other various electric circuits can be formed on the substrate by a printing method. In short, the present invention is not particularly limited as long as it is an electric circuit, an electromagnetic circuit, and an electric element formed by directly drawing the above-described ink on the substrate. In addition, since the adsorption layer is porous, the solvent in the ink can sufficiently penetrate into the adsorption layer.

As the ink, an ink in which fine particles or micelles of a solute such as an electrode constituent material are dispersed in a solvent is used. As described above, it is preferable that the particle size of the solute is larger than the particle size of the adsorption layer. As the solvent, for example, water, glycerin, diethyl glycol, a mixture of ethanol is used, water is 95% by weight or less, glycerin is 20% by weight
Hereinafter, 20% by weight or less of diethylene glycol and 10% by weight of ethanol are used. The solute is contained in the ink solution at 0.01 to 10% by weight.

When the ink is ejected onto the substrate using the ink jet method, the viscosity of the ink is selected from 1 to 20, preferably 2 to 4 cps, and the surface energy is
20-70, preferably 30-60 mN / m ² is selected. In the solute of the ink, S necessary for forming an element pattern such as an electrode or an insulating film in an electronic device is used.
Fine particles such as i, Ni, Au, Ag, ITO, and SiO2 are included. If necessary, an acrylic dispersion resin for adsorbing and hydrating the solute component or a coupling agent having an affinity for both is added to the ink.

After forming the oxide layer on the substrate, the oxide layer is dried at a temperature condition such that the solvent is physically completely removed, for example, at a temperature of 150 ° C. or higher.
Further, if necessary, annealing is performed at a temperature of 300 degrees Celsius or more. Through this step, the oxide layer becomes porous, and is fixed on the substrate by strong hydrogen bonding due to dehydration and sintering of grain boundaries. In order to print the above-described ink on the substrate, in addition to a method of directly discharging the above-described ink onto the substrate by an inkjet printer or a bubble jet printer, the ink is coated on the substrate by a dispenser device or a ballpoint pen device. Depends on the method.

The substrate includes a glass substrate, a high melting point resin substrate, a semiconductor such as silicon, or a metal film. Next, embodiments of the present invention will be described in detail. FIG.
Is a thin film transistor (T) according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view of the FT) 10. FIG. 2 is this plan view. FIG. 1 corresponds to the II section of FIG. This T
FT is depicted as a switching element of a pixel electrode of the liquid layer device.

Hereinafter, the structure of the TFT will be described. An adsorption layer (silicon dioxide) 13 made of porous oxide is formed on a heat-resistant substrate 12 made of glass or the like. A nickel electrode 14 as a gate electrode is laminated on this adsorption layer.

Further, on this nickel electrode 14, a silicon dioxide film 16 as a gate oxide film is laminated. Further, a silicon film 1 serving as a channel region is formed thereon.
8 are stacked. On the left and right sides of the silicon film, a nickel film 20 as a source electrode in close contact with the source region of the silicon film 18 and a nickel film 22 as a drain electrode in close contact with the drain region of the silicon film are laminated. This drain electrode has an ITO film 2 serving as a pixel electrode.
4 are stacked.

In FIG. 2, reference numeral 20A denotes a correlation insulating film provided between the gate electrode 14 and the source electrode 20. Reference numeral 16A corresponds to one dot of the insulating film 16 formed using an ink jet printer. These dots are collected to form a pattern of the insulating film 16. The same applies to the pattern formation of electrodes other than the insulating film. Next, a manufacturing process of the TFT will be described with reference to FIG. FIG. 3 is a sectional view showing each step of the TFT manufacturing process. In FIG. 3, the illustration of the substrate 12 in FIG. 1 is omitted. First, FIG.
As shown in (1), in order to form an adsorption layer 13 made of silicon dioxide on a substrate, a solution in which silicon dioxide was dispersed in a polar solvent was prepared and applied over the entire surface of the substrate. Next, this was dried under a temperature condition of 150 ° C. or more, and silicon dioxide was fixed as an adsorption layer 13 on the substrate. At this time, the thickness of the adsorption film was set to 50 microns.

Next, in order to form the gate electrode 14, an ink solution containing nickel was discharged onto the adsorption layer 13 by an ink jet method so as to form the pattern of the gate electrode 14 in FIG. At this time, the solvent in the ink is
As indicated by reference numeral 30, nickel was absorbed in the adsorption layer 13, and nickel in the ink remained on the adsorption layer 13. In this process, since the solvent 30 rapidly diffuses into the adsorption layer 13, the pattern of the gate electrode 14 as shown in FIG. 2 is accurately drawn on the substrate. After that, 15 degrees Celsius under pressurized condition
When the substrate is heated at 0 degrees to evaporate the solvent 30 from the adsorption layer, the nickel becomes porous and is fixed on the adsorption layer. At this time, the thickness of the nickel film became 0.2 μm. As a result, the ink pattern does not spread, and the solute in the ink becomes a fine pattern and is deposited on the adsorption layer 13.

Next, as shown in (2), a solution containing silicon dioxide 16 to be a gate insulating film is directly drawn on the gate electrode 14 by an ink jet method. At this time, the solvent of the ink penetrates into the nickel layer as the gate electrode 14 and the adsorption layer 13 respectively.
This solvent is evaporated by drying at 50 degrees and annealing at 500 degrees Celsius, and the pattern of the gate insulating film 16 is made porous and fixed on the gate electrode 14 and the adsorption layer 13.
For this annealing, for example, a laser or the like is used.
Since the solvent that has permeated the nickel layer 14 diffuses into the adsorption layer 13 beyond the nickel layer, the pattern of the gate insulating film 16 is formed on the nickel layer 14 without breaking the pattern directly drawn by the inkjet method. .

Next, as shown in (3), the TFT
Is directly drawn on the gate insulating film 16 by an ink-jet method. Thereafter, the semiconductor film is dried at 150 degrees Celsius, and is further subjected to laser annealing to be polycrystallized to obtain a semiconductor film with high mobility. Since the solvent of the ink containing silicon gradually penetrates toward the adsorption layer 13 through the gate insulating film 16 and the gate electrode 14, the silicon pattern is fixed on the gate insulating film 16 without being deformed. In the next step (4), when the ITO film 24 is directly drawn (printed) on the adsorption film 13 by using the ink jet method, the solvent 30 in the ink permeates into the adsorption layer 13 and The pattern of the ITO film 24 is formed as shown in FIG. After that, it is dried at 150 degrees Celsius and 40 degrees Celsius.
When annealing is performed at 0 degrees, the ITO film is fixed on the adsorption film 13.

In the next step (5), nickel-containing ink is directly drawn on the silicon film 18, the adsorption layer 13, and the ITO film 24 in the source region and the drain region by an ink-jet method. At this time, the solvent in the ink is finally absorbed up to the adsorption layer 13. The solvent is then evaporated by drying the substrate at 150 degrees Celsius. Thereafter, if necessary, a protective film such as silicon dioxide or polyimide is laminated to form the TF shown in FIGS.
T is completed. In the manufacturing process shown in FIG.
As a solvent for the ink solution, water 80% by weight, glycerin 10% by weight, diethylene glycol 20% by weight, and ethanol 10% by weight were used.

Next, another embodiment according to the present invention will be described. FIG. 4 is a diagram showing a cross section of a TFD (thin film diode) manufactured by a method similar to that of FIG.
This thin-film element consists of an electrode metal, a semiconductor,
The electrode metal and ITO 24 are formed by sequentially laminating using an inkjet method. At this time, since the solvent in the ink penetrates into the adsorption layer 13, each layer is fixed on the substrate in a pattern almost directly drawn by the inkjet method.

Also, MIM (Metal insulator metal)
The structure can be manufactured by a method similar to that described with reference to FIG.

FIG. 5 is a cross-sectional view of a further embodiment of the present invention.
FIG. 2 is a sectional view of a RAM. In the left side of FIG.
T is formed, and M (Pt) -Ferr is formed on the right side thereof as in FIG.
The structure of oelectric (PZT) -M (Pt) is formed. The pattern of each of these elements can also be formed by the ink-jet method as in FIG. 3. Since the solvent in the ink is rapidly diffused into the adsorption layer 13, the solute such as the electrode material in the ink is located at the target position. Uniformly fixed and laminated. Here, lamp annealing at 700 degrees Celsius was performed in order to turn PZT into a ferroelectric crystal.

FIG. 6 shows still another embodiment of the present invention. FIG. 6 is a plan view of the radio wave responsive sheet formed on the substrate. The radio wave response sheet is an information medium that can be read in a non-contact manner as an RF tag, and has a resonance circuit including a coil and a capacitor.

FIG. 6 shows an RF tag manufactured by the manufacturing method of the present invention as the radio wave responsive sheet 29. The radio wave response sheet 29 includes an RF tag 30A and a substrate 31. The RF tag 30A includes a substantially spiral coil 32 and a substantially rectangular capacitor 33 integrally formed at the center of the spiral of the coil 32 on a substrate 31 as a tag forming product. The capacitor 33 is composed of a dielectric 33a and a dielectric 33b stacked at the center of the spiral of the coil 32. This RF tag 30 is manufactured by the above-described inkjet method.

By patterning these coils and capacitors on the attraction layer formed on the substrate by the ink jet method, an accurate pattern of the coils and capacitors can be formed on the substrate. As a result,
The resonance frequency can be set correctly in the RF tag.

The electronic device to which the present invention is applied is not limited to those described above. The present invention is, of course, applicable to an electric circuit comprising a group of electronic devices.

[0032]

As described above, according to the present invention, since the adsorption layer for the ink solvent is provided on the substrate, it is possible to provide a printing method which can be widely applied to electronic devices. Also, it is possible to provide an electronic device in which an element pattern is accurately formed on a substrate. This pattern is uniformly formed at a target position on the substrate. In addition, patterning can be performed directly using data designed by a computer or the like, and since a photomask or the like is not required, design change is easy and small-volume production can be supported.

Further, by forming the adsorption layer from an inorganic porous material, heat resistance is improved, and as a result, thermal annealing or laser annealing can be applied to a substrate provided with this adsorption layer. Therefore, various types of electronic devices can be manufactured by a printing method.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a TFT element to which the present invention is applied, and corresponds to a II cross section in FIG.

FIG. 2 is a plan view of the TFT element.

FIG. 3 is a schematic view illustrating a manufacturing process of the TFT element.

FIG. 4 is a cross-sectional view of a thin-film element diode according to another embodiment to which the present invention is applied.

FIG. 5 is a FeRAM according to still another embodiment.

FIG. 6 is a plan view of a radio wave response sheet according to still another embodiment.

[Explanation of symbols]

Reference Signs List 10 TFT, 12 substrate, 13 adsorption layer, 14 gate electrode, 16 gate insulating film, 18 silicon electrode film, 2
0 source electrode, 22 drain electrode, 24 ITO film,
30 Ink solvent

Claims (15)

[Claims] 1. An electronic device in which a pattern of elements is formed on a substrate by a printing method, wherein the adsorption layer having an adsorption ability with respect to a solvent of an ink containing a material for forming the element pattern is provided. Formed on the substrate,
An electronic device, wherein the material is laminated as an element pattern on the adsorption layer by adsorbing the solvent in the adsorption layer. 2. The electronic device according to claim 1, wherein said adsorption layer mainly comprises an inorganic porous material. 3. The electronic device according to claim 1, wherein the heat-resistant temperature of the adsorption layer is 300 degrees Celsius or higher. 4. The electronic device according to claim 2, wherein said inorganic porous body is formed from an inorganic oxide. 5. The electronic device according to claim 2, wherein a pore diameter of the porous body is formed smaller than a particle diameter of the material component contained in the ink. 6. The electronic device according to claim 2, wherein the pore size of the porous body is 0.001 μm or more and 1 μm or less. 7. The method according to claim 1, wherein the inorganic oxide is SiO ₂ , Al ₂ O.
The electronic device according to claim 2, wherein the electronic device is at least one selected from the group consisting of ₃ , TiO ₂ , and ZrO ₂ . 8. The electronic device according to claim 4, wherein the particle diameter of the inorganic oxide is 10 μm or less. 9. The electronic device according to claim 1, wherein the element pattern includes an electrode film pattern and an insulating film pattern. 10. A method for manufacturing an electronic device, wherein an element pattern is formed on a substrate by a printing method, the method comprising: forming an adsorption layer having an adsorbing ability on a solvent of an ink containing a material for forming the element pattern on the substrate. Forming on the adsorption layer the ink, and adsorbing the solvent in the adsorption layer, and laminating the material as an element pattern on the adsorption layer. A method for manufacturing an electronic device. 11. The method according to claim 10, wherein said adsorption layer is mainly composed of an inorganic porous material. 12. The method according to claim 10, wherein the printing method is an inkjet method using an inkjet printer. 13. The method according to claim 10, wherein the adsorption layer is formed on the substrate by an inkjet method using an inkjet printer. 14. The method according to claim 10, wherein a solution obtained by dispersing an inorganic oxide in a solvent is printed on the substrate by an ink-jet method to form the inorganic porous body according to claim 11. 15. An element pattern printing method for an electronic device, comprising: forming an adsorption layer for a solvent of an ink containing an element pattern forming material of an electronic device on a substrate, and applying the ink onto the substrate.