KR100212089B1 - Apparatus and method for forming thin film - Google Patents

Abstract

An ink jet head having a plurality of nozzles for discharging liquid, a rotating device for rotating the coated substrate to which the liquid discharged from the ink jet head is attached about a rotation axis, and the ink jet head and the coated substrate in the vicinity of the rotation axis with respect to the substrate to be coated. Relative moving device for relative movement between the area and the separation area away from the axis of rotation, relative position between the ink jet head and the substrate to be coated moves relative to the separation area in the vicinity, The relative movement control device which controls the relative movement means so that the movement speed becomes small, and the rotational angular velocity by the rotating device corresponds to the relative position of the ink jet head and the substrate to be coated relatively moving from the vicinity to the separation region. It is a thin film forming apparatus which consists of a relative movement control apparatus which controls a relative movement means so that it may become small.

Description

Thin film formation method and apparatus

1 is a block diagram of a thin film forming apparatus according to a first embodiment of the present invention.

2 is a cross-sectional view of the ink jet head of the thin film forming apparatus.

3 (a) and 3 (b) are cross-sectional views of the nozzles of the ink jet head of the thin film forming apparatus.

4 is a configuration diagram of an input adjusting mechanism of an ink jet head of a thin film forming apparatus.

5 is an overall configuration diagram of a thin film forming apparatus.

6 is an operation of the thin film forming apparatus.

7 is a block diagram of a thin film forming apparatus according to a second embodiment of the present invention.

8 is an explanatory diagram of the thin film forming apparatus of FIG.

9 is an explanatory diagram of a thin film forming apparatus according to a third embodiment of the present invention.

10 (a), 10 (b), and 10 (c) are explanatory diagrams explaining the principle of discharge according to the fourth embodiment of the present invention.

11 is a block diagram for discharging the solution, embodying the same discharge principle.

12 is a characteristic diagram of solution discharge depending on the specific resistance field relationship obtained by the configuration in which the same discharge principle is specified.

13 is another configuration diagram for discharging the solution, embodying the same discharge principle.

14 is an overall configuration diagram of a thin film forming apparatus incorporating the same discharge principle.

15 is another configuration diagram according to the eighth embodiment of the present invention for discharging the solution, embodying the same discharge principle.

FIG. 16 is a characteristic diagram of solution discharge depending on the pressure wave-electrostatic force relationship obtained with the configuration of FIG. 15. FIG.

FIG. 17 is a characteristic diagram of solution discharge depending on the resistivity-field relationship obtained with the configuration of FIG. 15. FIG.

18 is a schematic configuration diagram of a spin coater used in the thin film forming method according to the ninth embodiment of the present invention.

19 is a sectional view showing the ink jet head of the thin film forming method according to the tenth embodiment of the present invention.

20 (a), 20 (b) and 20 (c) are explanatory views of a conventional thin film forming apparatus.

21 is an explanatory diagram of a conventional thin film forming apparatus.

22 is a perspective view of a thin film forming apparatus according to an eleventh embodiment of the present invention.

23 is a perspective view of the discharge head.

24 is a block diagram showing the configuration of a control unit.

25 is a control flowchart of a thin film forming apparatus.

FIG. 26 is another embodiment corresponding to FIG. 23. FIG.

FIG. 27 is another embodiment corresponding to FIG. 23. FIG.

28 is another embodiment corresponding to FIG.

* Explanation of symbols for main parts of the drawings

10: coated substrate 11: ink head

12: mounting base 13: spindle

21: air source 22: liquid reservoir

23: pressure adjusting mechanism 24: liquid inlet

25: air inlet 26: air outlet

27: liquid discharge port 50, 51: motor

53: personal computer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming method and a thin film forming apparatus, and more particularly, by discharging a solution material through a micronozzle to a thin film (100 μm or less in a broad sense, generally 10 μm or less) on a substrate or the like. ), And the present invention can be used in thin film forming processes suitable for manufacturing hybrid IC circuits, semiconductor circuits or micromachines, for example.

In recent years, thin film formation techniques have been used in various fields, and the actual method of film formation has been extensively studied, including spin coating, printing, and die coating, in addition to the need for vacuum devices such as sputtering and deposition.

Among them, in particular, the spin coating method is frequently used for resist coating, protective film formation, and the like in a semiconductor process. Hereinafter, a conventional spin coater will be described. 20 (a), 20 (b), and 20 (c) show the configuration and operating state of a conventional general spin coater.

20 (a), 20 (b) and 20 (c), reference numeral 101 denotes a spindle of a spin coater, 102 denotes a sample fixing substrate, 103 denotes a nozzle for discharging a coating liquid, 104 ) Are thin film forming substrates, 105 and 106 are liquids, 107 are thin films, and 108 are scattering droplets.

With such a configuration, as shown in FIG. 20 (a), the liquid 105 is discharged from the nozzle 103 toward the substrate 104 so as to be placed on the substrate 104. Next, as shown in FIG. 20 (b), the spin coater is rotated at a low speed ω ₁ to spread the liquid 106 on the substrate 104. As shown in FIG. 20 (c), the spin coater is further rotated at high speed omega ₂ to form a thin film 107 on the substrate 104.

However, according to the above conventional configuration, as shown in FIG. 20 (c), 80 to 90% of the liquid is thrown out by generating the useless scattering droplets 108. The reason for this is that, if the liquid 105 is not discharged in a large amount, the substrate 104 remains partially uncoated in a portion where compatibility with the liquid 105 is poor.

As described above, the conventional spin coating machine has a problem that the use efficiency of the liquid is poor and most of the coating liquid is wasted. In addition, in the case of forming a film by spin coating, since the liquid flows from the inside to the outer circumferential direction, the film thickness of the outer circumferential portion becomes large, which causes the disk itself to be distorted. On the other hand, conventionally, as a printing apparatus, a liquid ejecting apparatus for ejecting ink by using a micronozzle has been energetically developed. In recent years, as an application of such a liquid ejecting apparatus, a solution for ejecting a resist other than ink, for example, a resist A liquid discharge device or a circuit forming method applied to the preparation of an IC circuit or the like has been developed.

Hereinafter, as a prior art, the liquid substance application apparatus of Unexamined-Japanese-Patent No. 5-104052 is demonstrated as an example.

21 shows the configuration disclosed in Japanese Patent Laid-Open No. 5-104052.

In FIG. 21, reference numeral 201 denotes a liquid material supply unit, 202 denotes a discharge head connected to the liquid substance supply unit 201, 203 denotes a member to be coated (hereinafter referred to as a substrate), and 204 denotes a discharge head 202. ) And an XY stage for positioning the substrate 203 to face each other.

In addition, the discharge head 202 is provided in the pressure chamber 206 in which the liquid substance 205 is filled in communication with the liquid substance supply unit 201, and the discharge head 202 in the longitudinal middle portion of the pressure chamber 206. Displacement is imparted by the nozzle 207, piezoelectric element 208, which is open to the lower end surface of the diaphragm, and the displacement amplifier chamber 209 amplifies the displacement, and the pressure chamber 206 and the displacement amplifier chamber 209. It consists of a diagram 210 installed at the boundary of the.

In addition, the piezoelectric element 208 is driven by the control unit 211, and the displacement generated by the liquid crystal material 105 in the pressure chamber 206 is passed through the displacement amplifier chamber 209 and the diagram 210. As a result, the liquid material 105 in the pressure chamber 206 is pressurized, so that the liquid material 205 scatters downward in the form of the droplet 205a at the nozzle 207.

By adopting such a configuration, the liquid substance 205 is applied to the substrate 203 in an arbitrary pattern by scattering the liquid substance 205 contained in the nozzle 207 onto the substrate 203 in the form of a droplet 205a. It becomes possible.

In addition, the X-Y stage 204 is controlled by the control part 211 to a predetermined position.

However, in the above-described conventional configuration, since the piezoelectric effect is mainly used as the discharge method, there is a problem to be overcome as described below.

That is, in the discharging method by the pressure application method (hereinafter piezoelectric type) using the piezoelectric effect, the discharged solution is formed into the discharge liquid droplets having a diameter of two to three times the nozzle diameter. The miniaturization and precision of circuit patterns are limited.

Next, in order to refine the circuit pattern and increase the accuracy, it is necessary to reduce the nozzle diameter. However, the smaller the nozzle diameter, the larger the loss of adhesion in the nozzle part in the piezoelectric discharge method. In this case, there is a limit in reducing the nozzle diameter.

In addition, in the piezoelectric discharge method, when an organic solvent or the like having a large amount of dissolved air is used as the discharge solution, a cavity phenomenon occurs and discharge stability is lost, so that the type of solution that can be discharged is limited to a narrow range. do.

Therefore, it is an object of the present invention to provide a thin film forming apparatus and a thin film forming method which allow a coating liquid to be used with high efficiency by introducing a new liquid discharge head.

According to a first aspect of the invention, an ink jet head having a plurality of nozzles for discharging a liquid; Rotating means for rotating the coated substrate to which the liquid discharged from the ink jet head is attached about a rotating shaft; Relative movement means for relatively moving the ink jet head and the substrate to be coated between a region near the rotation axis with respect to the substrate to be coated and a separation region away from the rotation axis; A film made of a relative movement control means for controlling the relative movement means such that the relative movement speed by the relative movement means decreases in response to the relative position between the ink jet head and the substrate to be coated moves relatively from the vicinity to the separation region. A forming apparatus is provided.

According to a second aspect of the present invention, there is provided an ink jet head including a plurality of nozzles for discharging a liquid; Rotating means for rotating the coated substrate to which the liquid discharged from the ink jet head is attached about a rotating shaft; Relative moving means for relatively moving the ink jet head and the substrate to be coated between a region near the rotating shaft with respect to the substrate to be coated and a separation region away from the rotating shaft; A film forming apparatus comprising a relative movement control means for controlling the relative movement means such that the rotational angular velocity by the rotation means decreases in response to the relative position between the ink jet head and the substrate to be coated moved relatively from the vicinity to the separation region. Is provided.

According to a third aspect of the present invention, in the first aspect of the present invention, the relative movement control means rotates in response to the relative position of the ink jet head and the substrate to be coated relatively moved from the vicinity to the separation region. A film forming apparatus is provided, characterized in that the relative moving means is controlled to reduce the rotational angular velocity by the means.

According to a fourth aspect of the present invention, a coated substrate on which a liquid discharged from a liquid discharge member having a plurality of nozzles for discharging liquid is attached is rotated about a rotation axis; The greater the relative movement of the liquid discharging member and the coated substrate toward the separation region in the vicinity between the region near the coated substrate near the rotation axis and the separation region of the substrate to be separated from the rotation axis, the more the relative movement speed is reduced. There is provided a film forming method comprising a process of moving relative to each other.

According to a fifth aspect of the present invention, a substrate to be coated on which liquid discharged from a liquid discharge member having a plurality of nozzles for discharging liquid is attached is rotated about a rotation axis; The more the relative movement of the liquid ejection member and the coated substrate toward the separation region from the vicinity of the coated substrate near the rotation axis and the separation region of the coated substrate away from the rotation axis, the more the angular velocity of the coated substrate increases. There is provided a film forming method comprising a process of moving relative to each other to further reduce.

According to a sixth aspect of the present invention, in the fourth aspect of the present invention, there is provided a film forming method, which further reduces the rotational angular velocity of the substrate to be coated in the moving step.

According to a seventh aspect of the present invention, an ink jet head having a plurality of nozzles for discharging a liquid and a substrate to which liquid is attached are rotated at a first relative speed sufficient for the liquid to adhere to the substrate surface, so that the entire area of the substrate surface is rotated. After the coating step of uniformly applying the liquid to achieve the first coating state, and after the coating step, the ink jet head and the substrate are rotated at a second relative speed higher than the first relative speed to apply the excessively applied coating liquid. A film forming method is provided, which comprises a step of forming a film on a substrate, the film of which achieves a uniform second coating state than the first coating state by being scattered from the first coating state.

According to an eighth aspect of the present invention, in the first aspect of the present invention, the ink jet head is constituted by a nozzle, and a plurality of ejections are arranged in one direction so that the ejection amount of liquid gradually increases in one direction. A film forming method is provided, characterized in that the ejection section with the minimum ejection amount is arranged near the substrate.

Example 1

1 is a schematic configuration diagram of a spin coater of a first embodiment of the present invention.

In FIG. 1, reference numeral 10 denotes a disk-shaped substrate to be coated, numeral 11 denotes an ink head, numeral 12 denotes a mounting base of the substrate to be coated 10, numeral 13 denotes a spindle of the mounting plate 12, and 50 is a motor as an example of the rotation means.

Here, the ink jet head means ejecting liquid from a micronozzle (typically, nozzle diameter of 0.2 or 0.1 mm or less), controlling the ejection state of the liquid by an electric signal, and attaching the liquid to the recording medium. do.

The ink head in this embodiment has a plurality of such micronozzles, and more specifically, 48 nozzles are arranged in the radial direction of the substrate to be coated 10 at intervals of 10 / mm. As a structural example of the micronozzle mentioned above, 50 nozzles whose hole diameter is 200 micrometers or less, for example, 50-60 micrometers are arrange | positioned at intervals of 0.5 mm.

Since the discharge nozzle used in the conventional spin coating machine has an internal diameter of 0.5 to 1 mm, it is difficult to control a very small amount of discharge. However, as in the present embodiment, a fine pattern can be drawn by using a defined ink jet head. At the same time, it is possible to form a uniform and very thin film.

In this embodiment, first, as shown in FIG. 1, the ink jet head 11 is rotated relative to the substrate 10 at a speed V while rotating the substrate to be coated 10 at an angular velocity θ. By moving, the coating liquid is discharged from the nozzle to adhere the coating liquid onto the substrate to be coated 10.

Next, once the substrate to be coated 10 is rotated once, 48 coated lines are generated by the ink jet head 11 at 100 占 퐉 intervals, that is, as a result, a line having a width of 4.8 mm is drawn. Further, in this case, if the line width is appropriately selected, adjacent lines are connected to each other to form a thin film having a predetermined thickness. Therefore, when such a suitable condition is found out and the amount of movement by the relative movement speed V of the ink jet head 11 when the substrate to be coated 10 rotates once is set to 4.8 mm, the thin film is formed by the so-called spiral one stroke recording. Can be formed.

In addition to such one-stroke recording, a thin film can be formed even by several overlapping recordings.

More specifically, by setting the relative moving speed V of the ink jet head 11 and the angular speed θ of the substrate to be coated 10, the ink jet head 11 is moved relative to a predetermined amount, for example, 4.8 mm. Even if the substrate to be coated 10 is rotated several times and overwritten, the thin film can be formed. In this way, it is suitable for reliably forming a thinner film by drawing thinner and thinner lines than 10 / mm.

Specifically, with reference to FIG. 1, when the rotational center of the substrate to be coated 10 is set to zero origin and the distance in the radial direction is X, the substrate to be coated 10 rotates at an angular velocity θ, and the ink jet head (11) starts discharging at position Xs while moving at a speed V in the radial direction (X direction) of the substrate to be coated, and stops discharging at the outer peripheral position Xe of the substrate to be coated 10 to form a thin film. To complete.

In this operation, in order to form a thin film having the same thickness over the entire area of the substrate to be coated 10, when the discharge amount from the ink jet head 11 is a constant value Q, it is necessary to satisfy the following equation (1). have.

(Wherein K ₁ is an integer and K ₁ 0)

In addition, in order to draw a line with the same resolution over the entire area of the substrate to be coated 10, it is necessary to satisfy the following equation (2).

(Wherein K ₂ is an integer and K ₂ 0)

That is, since the coated area of the disk-shaped substrate increases from the outside to the center, the speed V needs to be reduced as it goes from the center to the outside, and if the rotation speed is constant, the peripheral speed is located from the outside of the center. Since the speed is high, in order for the peripheral speed at the recording position of the ink jet head to be constant, it is necessary to decelerate as the rotational speed X increases.

For example, if V and e are constant, the peripheral speed in the center portion is lowered. Therefore, even if the coating lines have the same density, the center line becomes thicker, and the center part becomes thicker and thinner in the outer peripheral part. Thin films are formed, and in addition, the lines of the outer circumferential portion do not overlap and may remain in the form of lines.

In addition, when e is kept constant while the formula (1) is satisfied, the coating amount is constant throughout the substrate to be coated, but the central portion becomes thick due to the low peripheral speed, and is applied by a low-density line. Since the outer circumferential portion is applied by a thin, high-density line, the outer circumferential portion is well overlapped with the application line, and a uniform film is formed.

As can be seen from these examples, it is preferable to satisfy at least one of the formulas (1) and (2) in order to form a uniform and uniform thickness thin film throughout the substrate to be coated, and more preferably to satisfy both forms. Do.

Next, FIG. 2 is a schematic diagram showing a typical configuration of the ink jet head according to the present embodiment.

In Fig. 2, reference numeral 11 denotes an ink jet head, 21 denotes an air supply source, 22 denotes a liquid reservoir, and 23 denote a pressure adjusting mechanism for adjusting a flow rate of air supplied to the head 11, 24 is a liquid inlet, 25 is an air inlet, 26 is an air outlet, and 27 is a liquid outlet.

In this case, the liquid discharge port 27 and the air discharge port 26 are provided concentrically on the ink jet head 11.

With respect to the ink jet head 11, air flows in from the air inlet 25 through the pressure adjusting mechanism 23 in the air supply source 21, and air flows at a constant flow rate flow out from the air outlet 26. Doing.

On the other hand, in the liquid reservoir 22, the coating liquid is supplied via the liquid inlet 24.

In addition, the air supply source 21 is also connected to the liquid reservoir 22, and a pressure is applied to the liquid in the ink jet head 11 to balance the air pressure in the vicinity of the liquid discharge port 27 generated by the air flow. In this way, the coating liquid is held at the liquid discharge port 27.

3 (a) and 3 (b) are enlarged views of the nozzle part of FIG.

As shown in FIG. 3 (a), the air discharge port 26 and the liquid discharge port 27 are arranged concentrically, and the air discharge port of a constant flow rate flows out from the air discharge port 26. As the stream flows out, the pressure Pa generated by this air flow is generated at the outlet of the liquid discharge port 27.

On the other hand, since the air pressure is applied to the liquid reservoir 22, the pressure Pi is generated in the liquid in the liquid discharge port 27.

Next, Pa and Pi are nearly equally balanced, so that the coating liquid is maintained at a stable meniscus at the liquid discharge port 27, so that the coating liquid is retained at the liquid discharge port 27.

On the other hand, as shown in FIG. 3 (b), when the air flow supplied to the ink jet head 11 by the pressure adjusting mechanism 23 decreases, the pressure generated at the outlet of the liquid discharge port 27 is reduced to Pa. It becomes smaller Pb, the meniscus collapses by the pressure difference Pi-Pb, and a coating liquid is discharged. On the other hand, since the air continues to flow through the air discharge port 26, the air is discharged outward by being wrapped in this air flow so as to pass through the air discharge port 26 as the discharge liquid.

Next, FIG. 4 shows an exemplary configuration of the pressure adjusting mechanism 23. As shown in FIG.

4, the air flow from the air supply source flows into the inlet A of the solenoid valve 41 and flows out via the outlet B or C along the solenoid valve 41. As shown in FIG.

Here, the solenoid valve 41 is to switch the outlet to B or C by the electrical signal.

In the case where the inlet port A communicates with the outlet port C, the pressure P ₁ of the liquid reservoir and the pressure Pa by the air flow are almost equal in the state of FIG. 3 (a).

Then, when the discharge signal is input to the solenoid valve 41, the flow path is switched from C to B.

As shown in FIG. 4, a flow path resistor 52 including a large pressure loss in the flow path, such as a throttle valve, is connected to the outlet B, and a pressure loss occurs when air passes through the flow path resistor 52. Then, the pressure caused by the air flow in the ink jet head is lowered from Pa to Pb, so that the coating liquid is discharged as shown in FIG. 3 (b).

Hereinafter, a specific embodiment in which the coating liquid is actually ejected and applied onto the substrate to be coated using the ink jet head having the above-described configuration will be described.

In this embodiment, as the substrate to be coated, a polycarbonate phase change (photo-crystallization) optical disk is used, and as the coating liquid, a UV (ultraviolet) curing solution is used to form a protective film on the metal deposition surface. The diameter of the disk is 130 mm, and the application range of the UV curing liquid is a radius of about 20 mm or more.

Therefore, Xs = 20 mm and Xe = 65 mm in FIG.

In addition, the UV curing liquid is a resin solution which is cured and solidified by irradiating ultraviolet rays. Specifically, an acrylic ester composition is used, and the physical properties thereof are 23 cP in viscosity, 1.07 in specific gravity, 29 dyn / cm in surface tension, and The hardening shrinkage is 9.8%. Under such conditions, the amount of liquid required to form a protective film having a film thickness of 5 µm was estimated to be approximately 70 mg.

Therefore, since the liquid ejection amount by the ink jet head is about 300 mg / min, a protective film having a thickness of about 7 μm is formed by completing the coating operation in about 20 seconds.

In this case, equation (1) can be expressed by the following equation (3).

(V is mm / s, X is mm)

Here, how the constant K ₁ is determined is demonstrated. As described above, application is started at a position where the distance X in the radial direction is 20 (mm) from the origin 0 of the substrate to be coated 10, and the application is completed at a position where X = 65 (mm), and the application time is In the case of 20 seconds, the coating time is determined from the film thickness and the coating area. From this, equation (1) is

(dx / dt) * X = K ₁ , and solving this differential equation gives (1/2) * X ² = K ₁ * t + C (where C is an integer). When the application start time is t = 0 (sec) and X = 20, (1/2) * 20 ² = C, C = 200, and the application end time is t = 20 (sec) and X = 65, (1/2) * 65 ² = K ₁ * 20 + C

Substituting C = 200 into this equation results in K ₁ = {(1/2) * 65 ² -200} /20=95.6, so that K ₁ can be determined to be 95.6.

On the other hand, Equation (2) relates to the thickness of the line and the number of overlapping applications (or line density) during the coating operation. Therefore, three cases of K ₂ = 32000, 36000, and 40000 (e: rpm, X: mm) are examined. Is done.

In practice, using a personal computer, control is performed so that the speed V and the angular velocity θ in the X-axis direction satisfy the expressions (2) and (3), respectively, through software.

Specifically, in order to control the speed V according to equation (3), it is convenient to express V as a function of time. That is, since V = dx / dt, equation (3) is converted into the following relationship equation (4).

Next, solving the differential equation represented by equation (4) and substituting the condition of X = 20mm at t = 0, since X is represented by the following equation (5), V can be expressed by the following equation (6). .

Therefore, V is controlled by a personal computer so as to satisfy Expression (6), and actual application is performed.

5 is a configuration diagram of an application apparatus using a personal computer according to the present embodiment.

In Fig. 5, the same reference numerals are given to the same configuration as in Fig. 1, 51 is a motor, 52 is a motor driver, 53 is a personal computer used as a control means, and 54 is a moving table.

In this configuration, the substrate to be coated 10 is moved and rotated by the motor 50, and the relative movement of the ink jet head 11 and the substrate to be coated 10 is made by the motor 51.

The motors 50 and 51 are driven by the motor driver 52, which is connected to the personal computer 53, and the driving is controlled by software installed in the personal computer 53.

6 shows an example in which V, e and discharge signals are controlled. In relation to Fig. 6, the horizontal axis indicates the position X from the radial center of the optical disk, and the vertical axis indicates the speed V in the X direction of the ink jet head and the rotational speed θ of the disk.

First, in the initial state, the ink jet head is at a position of X = 10 mm, and the disk is rotating at 1800 rpm.

Next, when the ink jet head starts relative movement at V = 290 mm / s and reaches the position of X = 20, the ejection signal is inputted to discharge the paint liquid, whereas the ink jet head and the disc are shown in the figure. V and inverse to X The motor rotates while decelerating.

Next, when the position of X = 65 is reached, the discharge stop signal is input so that the velocity V and the angular velocity θ are decelerated to zero. Below, under the above conditions, K ₂ = 32000, 36000, 40000 ( : rpm, X: mm) The measurement result was shown for three cases.

First, under the condition of K ₂ = 32000, since the rotational speed is low and the density of the coating line is low, there is a tendency that the warp of the stripe remains slightly.

Next, under the condition of K ₂ = 36000, a thin film having a smooth film thickness of 6 to 8 μm can be formed.

On the other hand, under the condition of K ₂ = 40000, since the rotation speed becomes too high, the centrifugal force is excessively generated, and during the coating, the coating liquid attached before this flows outward and flows outward, and as a result, radial streaks tend to occur .

Therefore, in this embodiment, while the condition of K ₂ = 36000 is more preferable, one formed under other conditions may be used depending on the kind of thin film to be formed.

In addition, in order to form a uniform and uniform thin film over the entire substrate to be coated, it is preferable to satisfy both the formulas (1) and (2), but at least one of the conditions may be satisfied depending on the type of the thin film to be subjected. In some cases.

As described above, in the present embodiment, by satisfying at least one or both of Equations (1) and (2), i.e., relative velocity V moves from the center outward, i.e., near the axis of rotation of the spindle. Decelerates as it moves outward toward the substrate area away from the rotation axis in the substrate area, and / or By slowing down as the value of X increases, it is possible to form a thin film having a uniform and uniform thickness throughout the substrate to be coated.

Example 2

Next, a second embodiment of the present invention will be described in detail.

As described in the first embodiment, a predetermined thin film is formed by appropriately setting K ₁ and K ₂ according to the conditions of the formulas (1) and (2) according to the type or film thickness of the thin film formed by application. Although it is possible to do so, further examination may be necessary depending on the process of the thin film to be formed.

For example, in the case of K ₁ = 191.2 of formula (1), which can terminate the application in about 10 seconds to form a film thickness of about 3.5 μm, K ₂ of formula (2) is changed up to 60000 kinds. Although the experiment was carried out, a smooth thin film was not obtained, and the circumferential stripe pattern remained. Such a phenomenon can be considered to occur when there is a limit to miniaturization of discharge droplets of the coating liquid, or when the rotation speed of the rotating shaft is too low.

In the second embodiment, the thin film is smoothly leveled in consideration of the case where the thin film is not sufficiently uniform in the coating operation by the ink jet head.

7 is a schematic configuration diagram of the spin coater of the second embodiment of the present invention.

Similarly to the first embodiment, with reference to FIG. 7, the coating liquid ejecting head 70, which is an ink jet head, is relatively moved while rotating the coated substrate 10 made of polycarbonate, and the thin film is applied to the coating liquid of the UV curing liquid. To form. Further, in the second embodiment, the air outlet head 71 is further provided adjacent to the coating liquid discharge head 70, and the air flow is immediately after the coating liquid is attached to the coated substrate 10. By blowing, the coating liquid can be flowed to smooth the coating film.

Specifically, in the second embodiment, the same ink jet head and coating liquid as in the first embodiment were used, and K ₁ = 191.2 in Equation (1) and K ₂ = 60000 in Equation (2) were examined. Is done. First, when the air outlet head 71 is not used, a stripe pattern remains and a smooth coating film cannot be obtained.

On the other hand, as shown in FIG. 7, when the air outlet head 71 is added, a thin film of 3 to 4 m can be formed.

Specifically, the air outlet head 71 is configured to align 24 nozzles having a pore diameter of 100 μm and to let the air flow out at a pressure of about 0.15 kg / cm 3. The air flow rate is 100 to 200 m / s, and the airflow can be thought of as the flow of the layered flow zone with less air fluctuations.

8 shows a method of making the coating film uniform by the air flow.

Regarding FIG. 8, first, immediately after the discharge liquid adheres to the substrate to be coated 10, adjacent lines are in a state indicated by the area A separated from each other. Thereafter, the coating liquid spreads over time, wets the substrate 10 to be coated, and is in a state as indicated by the region B. As a result, the coating liquid is dried and cured as it is.

If the air flow is blown into the coating liquid before the dry curing of the thin film, the coated film of the region B in the thinned state is further flowed to cause microscopic vibration, resulting in a uniform thin film like the region C.

As described above, in the second embodiment, the air outlet head 71 is provided adjacent to the coating liquid discharge head 70, and immediately after the coating liquid is adhered to the substrate to be coated. By blowing the flow, the coating liquid can be flowed and vibrated to form a uniform coating film.

Example 3

Next, a third embodiment of the present invention will be described in detail.

The third embodiment is for improving the uniformity of the formed thin film as in the second embodiment, but in this embodiment, the discharge liquid is charged to uniform the coating film. Specifically, the electrode 93 is provided on the surface of the air discharge port 92 of the ink jet head having the same configuration as that of the first embodiment, and is held in the electrode 93 and the liquid discharge port 91. The potential difference is provided by the power supply 90 between the discharge liquid 94 which exists, and the droplet 95 to discharge is charged, and the to-be-applied substrate 10 used in this embodiment and the discharge liquid ( 94) is the same as in the first embodiment.

9 is an enlarged view of the nozzle portion of the ink jet head of the third embodiment.

9, the liquid discharge port 91 and the air discharge port 92 are made of an insulating material, and an electrode 93 is provided on the outlet side surface of the air discharge port 92. As shown in FIG. The power supply 90 is also connected to apply a potential difference between the electrode 93 and the discharge liquid 94 held at the liquid discharge port 91. In such a configuration, when the potential difference is applied by the power supply 90, the discharge liquid 94 is charged according to the capacitance between the electrode 93 and the discharge liquid 94.

Next, the droplets 95 discharged to the outside are charged and emerged to reach and adhere to the substrate to be coated 10. The charged drop 95 is maintained in a charged state when attached to a substrate made of an insulating material such as polycarbonate.

Since the attachment portion of the droplet 95 previously attached to the substrate to be coated 10 and the droplet 95 subsequently arriving at the substrate to be coated 10 are charged with the same polarity, they repel each other. As a result, the attached liquid acts on the substrate to be coated 10 in a wider direction. Specifically, in the third embodiment, K ₁ = 191.2 in Equation (1) and K ₂ = 60000 in Equation (2) using the UV curing liquid of the optical disc made of polycarbonate, and the electrode ( A potential difference of approximately 600 V is applied between the 93 and the discharge liquid 94, and coating is performed for 10 seconds.

Next, when the liquid was not charged, a stripe pattern remained and a smooth thin film was not formed. However, when the discharge liquid was charged by applying a potential difference between the electrode 93 and the discharge liquid 94, the thickness was 3 to 4 μm. It was possible to form a smooth thin film of.

As described above, in the third embodiment, a uniform coating film can be formed by charging the discharge liquid by applying a potential difference between the electrode and the discharge liquid provided around the air discharge port.

In addition to the configuration for charging the discharge liquid of the third embodiment, the air outlet head described in the second embodiment is provided, and the air flow is blown immediately after adhesion of the coating liquid to the substrate to be coated and before dry curing. By combining these, a more uniform coating film can be formed more reliably.

In all the above-described embodiments, the types of the substrate to be coated and the coating liquid are not limited to those exemplified above, but the electrical or optical functions of the resist coating on the silicon substrate, the glass substrate, the ceramic substrate, the metal plate, and the like. It can also be applied to the formation of the guinea functional thin film. However, the coating liquid is preferably a non-quick dry resin solution in order to prevent the nozzle from being clogged during application.

In the present invention, under the control of the angular speed and the moving speed, the substrate to be coated and the ink jet head are moved relative to each other between an area near the spindle and an area further away from the spindle. By this movement, the liquid is discharged to the substrate to be coated through the plurality of nozzles of the ink jet head, thereby forming a coating film having excellent uniformity on the substrate to be coated.

Furthermore, an air outlet head is provided to blow air into the substrate to be coated immediately after discharging the liquid onto the substrate to be coated.

In addition, a charging means for charging the liquid discharged from the ink jet head is provided so that the portion to which the droplet is attached to the substrate to be coated is adhered, and the droplet reaching the substrate to be coated subsequently repels each other. The liquid moves in a direction in which the liquid attached to the applicator substrate falls more widely.

With the above-described configuration, the present invention provides a thin film forming apparatus which can form a thin film uniformly over the entire area of the substrate to be coated without waste of the coating liquid or thickening of the outer peripheral portion of the film by a very simple structure. do. In addition, there is provided a thin film forming apparatus having a high degree of freedom capable of forming a thin film having a predetermined film thickness by changing conditions in various ways according to the purpose.

Example 4

Hereinafter, as a fourth embodiment of the present invention, the resistance is 10 ⁵ The method of forming a thin film using the solution which is cm or less is demonstrated.

10 (a), 10 (b) and 10 (c) are explanatory views showing the discharge state in the case of discharging a solution using electrostatic force. In FIGS. 10 (a), 10 (b) and 10 (c), (121), (124) and (126) are nozzles, (122) are coated members, and (123) to (127) are solutions of Indicates the discharge state. When the solution is discharged using electrostatic power, the discharged state can be broadly classified into the states shown in the tenth (a), the tenth (b), and the tenth (c).

That is, three representative discharge states, in which the solution is discharged in the form of a droplet 123 independently of the nozzle 121 and is attached to the to-be-coated member 122, and the tenth (b) Fig. 10 is a state in which a solution is discharged and attached to the to-be-coated member 122 by pulling the thread indicated by 125 at the nozzle 124, and at the nozzle 126 at the nozzle 126 (127). The solution is discharged in the spray state indicated by) and is attached to the member to be coated 122.

In order to form a fine thin film, it is necessary to discharge the solution in a state causing the stringing phenomenon of FIG. 10 (b), but by the experiment of the present inventor, it was found that the discharge state depends on the resistance of the solution. That is, the resistance is 10 ⁵ If it is cm or less, the electrostatic force does not successfully act on the solution, and good stringing cannot be achieved, so the resistance of the solution is 10 ⁵ It is preferable that it is cm or more.

Hereinafter, the experimental content will be described in detail. 11 is a block diagram showing a basic configuration for discharging and applying a solution by electrostatic force.

In FIG. 11, reference numeral 128 denotes a solution supply port, 129 denotes a solution discharge port, 130 denotes a solution, 131 denotes a coated member on which a thin film is formed, and 132 denotes a coated member. The back electrode provided at the back of (11), 133 is a nozzle, and 134 is a high voltage power supply.

In this configuration, the solution 130 is directed from the nozzle 133 to the coated member 131 by an electric field generated by applying a voltage between the back electrode 132 and the nozzle 133 by the high voltage power supply 134. Discharged.

FIG. 12 shows the discharge state of the solution in the case of discharging the solution using the electrostatic force in the configuration shown in FIG. 11 in relation to the specific resistance and the applied voltage.

In Fig. 12, the horizontal axis represents the resistivity of the solution, the vertical axis represents the strength of the electric field by the electrostatic force, the a part is a state in which the solution is not discharged, and the b part is a state in which the solution is discharged in the form of an independent liquid drop. 10 (a) state), part C is a state in which the solution is ejected in the form of a spray (state 10 (c)), d is a state in which the solution is ejected in a stringing state (state 10 (b)) Indicates.

As described above, in order to form a fine pattern thin film, it is necessary to discharge the solution in a stringing state in which the discharge solution can be controlled.

Thus, first, the resistivity of the solution is 10 ⁵ so that the state of part d in FIG. 12 is achieved. On the premise of selecting cm or more, furthermore, the energy (strength of the electric field) applied to the solution is adjusted to a level at which the stringing state is achieved, so that a favorable thin film formation can be achieved.

For example, a MOD (Metallo-Organic Deposition) solution, a sol-gel solution, and the like, which are being developed as a DRAM capacitor and a nonvolatile memory material, generally include hydrocarbon-based organic solvents such as ethanol and methanol as a solvent. And the specific resistance of these solutions is generally 10 ⁷ cm or more.

When these solutions are discharged by a conventional method using a piezoelectric element, cavitation occurs and a good solution discharge cannot be achieved. However, when the solution is discharged by the configuration of the present embodiment, as shown in FIG. 10 ⁵ Since a solution discharge in a stable stringing state can be achieved because it has a high resistivity of cm or more, the piezoelectric thin film or the dielectric thin film can be directly formed at any place on the substrate without using an exposure process or an etching process.

The same applies to discharging the solution in the configuration shown in FIG. 13, not in the configuration shown in FIG.

In this configuration, the principle of discharging the solution with electrostatic power is similar to that of FIG. 11, except that the metal film 135a formed on the upper surface of the member to be coated 135 is used as one electrode for generating an electric field. Alternatively, any configuration can be selected, depending on the application.

Subsequently, a thin film forming apparatus to which the above-described thin film forming method is actually applied will be described in detail.

14 shows the construction of a thin film forming apparatus according to a fourth embodiment of the present invention.

In FIG. 14, reference numeral 137 denotes a solution discharging part for discharging a solution, reference numeral 138 denotes a coated member on which a thin film is formed by discharging the solution, and reference numeral 139 denotes a heater block for heating the coated member 138; 140 is an XY stage for moving the member to be coated so as to discharge the solution to any place on the member to be coated 138 to form a thin film. The motor 140x for moving the member to be coated 138 in the X direction. And a motor 140y for moving in the Y direction. In addition, 141 is a heat insulating plate disposed to prevent the conduction of heat generated from the heater block 139, 142 is a solution discharge portion 137 as a Z stage to position the solution discharge portion 137 in the vertical direction. ) Has a motor 142Z which can move in a Z direction perpendicular to the X and Y directions. Reference numeral 143 denotes a solution supply unit that stores the solution to be discharged and supplies the solution to the solution discharge unit 137.

Reference numeral 144 denotes a control unit for controlling the solution discharge amount of the solution discharging unit 137, the temperature control of the heater block 139, and the movement distance control of the X-Y stage 140 and the Z stage 142.

In such a device configuration, after positioning the solution discharging portion 137 with the Z stage 142, the solution is directed from the solution discharging portion 137 toward the to-be-coated member 138 according to the above discharge principle. Discharged. At this time, if necessary, the X-Y stage 140 is moved during or after completion of discharge.

Moreover, since the heater block 139 which is a heating mechanism for heating the to-be-coated member 138 is provided, after discharging a solution onto the to-be-coated member 138, by heating the to-be-coated member 138, a solvent Can be evaporated quickly to form a thin film, and therefore, the time required to form the thin film can be shortened.

Moreover, the same effect can be acquired also if the method of heating using a lamp etc. as a heating means is employ | adopted. Of course, when drying at room temperature is enough in time, a heating process can also be skipped. Further, the substrate is not limited to the flat plate, and the thin film can be formed by the same method even if the substrate is curved.

Furthermore, in addition to the device configuration shown in FIG. 14, by adding a function of filling an atmosphere of a place where a thin film is formed with an inert gas, a solution is discharged such that it reacts with moisture in the air and deteriorates its characteristics. Even if it is, the characteristic can be maintained without being affected by the atmosphere.

As means for filling the atmosphere of the place where the thin film is to be formed with an inert gas, for example, the place where the thin film is formed may be surrounded by a container, and an inert gas may be introduced therein at a pressure higher than air, or a vacuum pump may be used. The pressure difference between the place where the thin film is formed and the atmosphere may be filled using an or the like, and the place where the thin film is formed may be filled with an inert gas.

In addition, the head of the solution discharging unit 137 for discharging the solution may be constituted by a multi-nozzle head having a plurality of nozzles, which may simultaneously form a thin film by different solutions or a plurality of circuits having a predetermined interval. The pattern can be created at the same time, and the productivity is improved.

Example 5

Hereinafter, a fifth embodiment of the present invention will be described. In the fourth embodiment, the specific resistance is high (10 ⁵ cm or more), the solution was described, but in the present embodiment, a solution having a low specific resistance (10 ⁵ will be described below.

Some of those sold in sol-gel solutions. For example, SrTiO ₃ sol-gel solution containing acetic acid as the main solvent has a specific resistance of about 4 × 10 ^3. Since it is as low as cm, no stringing phenomenon is caused by the electrostatic force, and stable solution discharging cannot be achieved by discharging according to the principle of the fourth embodiment. This reason can be considered that the acetate becomes dissociated ions in the solvent and lowers the specific resistance. Therefore, if the isobutylbenzene, which is a hydrophobic organic solvent, is mixed with the solution at a ratio of 1: 1 as a second solvent for the purpose of increasing the specific resistance, the specific resistance is 10 ⁷ as contained in part d of FIG. It rises to cm, and a good solution discharge is possible.

As mentioned above, in addition to the 1st solvent which melt | dissolves a medium well, by using the 2nd solvent for the purpose of adjusting specific resistance, the solution which can be discharged favorable by electrostatic power can be manufactured.

Generally, the second solution is an organic solvent having a lower polarity than the first solution, and the compatibility with the first solution is good, for example, aliphatic hydrocarbons, naphthenic hydrocarbons, mono or dialkylnaphthalenes, pe Organic solvents, such as aromatic hydrocarbons, such as a netyl silical, are preferable.

In addition, the process after discharge can be performed similarly to 4th Example, and can form a thin film.

Example 6

Hereinafter, a sixth embodiment of the present invention will be described. In the sixth embodiment, the discharge of a solution having a relatively high viscosity (10-20 CP or more), particularly a resin solution, will be described.

The method of forming a thin film in which a resin-dissolved solution is discharged onto a member to be coated and then dried to obtain a resin thin film can be applied to a mask material and various applications in the production of electronic component circuits. Since these solutions are generally high in viscosity and often in the range of 10 to 20 CP or more, when the conventional piezoelectric discharge method is used, the discharge is often impossible or unstable.

However, it has been found that, using the electrostatic discharge method, even at a viscosity of 20 to 30 CP, a highly accurate pattern can be produced as long as the solution is a resin solution. In addition, the specific resistance of the solution in the resin solution is 10 ⁵ Solutions lower than cm are also present.

Referring to FIG. 12, it is thought that it is impossible to discharge these resin solutions with low specific resistance, but according to the inventor's examination of the resin solution, exceptionally, even when the specific resistance is low, a stringing state may occur. I found that.

For example, the specific resistance of aqueous PVA solution containing 5% PVA (polyvinyl alcohol) is 500 The discharge of the solution in the streamed state was confirmed by using the discharge method using the electrostatic power of about cm. The reason for this is that not only the specific resistance but also the magnitude of the molecular weight of the solute itself should be taken into consideration as a property value factor that causes the stringing phenomenon by the electrostatic force.

The reason why the resin solution tends to cause stringing phenomenon is not necessarily the cause, but it can be considered that the resin of the polymer tends to cause stringing phenomenon in the same way that the polymer protein pulls the yarn.

On the other hand, the process after discharge can be performed similarly to the fourth embodiment to form a thin film.

In view of the above, when the resin is used as the discharging solution, since the thin film formation can be performed by substantially expanding the usable range of the specific resistance value, the mask formation during the production of a normal electronic component circuit is applied to the resin coating, exposure, and etching. By forming a thin film from the resin solution according to the ejection principle of the fourth embodiment, a mask can be formed by only one process, and the number of steps required during the circuit fabrication is reduced. It can have a big effect by lowering the price.

Example 7

Hereinafter, a seventh embodiment of the present invention will be described. In the seventh embodiment, a method of forming a metal thin film will be described.

If the thin film can be formed by directly discharging the solution containing the fine metal powder on the member to be coated, it is possible to directly form fine wiring, which can have a great effect on miniaturization and low cost of the circuit. What is necessary is just to suspend using a dispersing agent, when preparing the solution containing the fine metal powder stably.

An example of a dispersant is a surfactant, which is adsorbed on a solid-liquid interface to lower and stabilize interfacial energy. That is, since this surfactant forms an adsorptive protective film on the surface of the fine particles, in a stable dispersed suspension, since the particles do not directly contact or collide with each other, the electrical conductivity is low, that is, the specific resistance is 10 ^5. It can be set as the solution more than cm.

In addition, although the adsorption protective film can be formed only with a surfactant, there are also substances that make the surface coating more rigid.

Generally, these materials are called protective colloids or emulsion stabilizers, but by adding such materials, it is possible to reliably avoid collisions between fine powders and to prepare suspensions with stable electrical properties.

As the protective colloid, natural rubber, starch, alginate, protein, lecithin, ether with fiber, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid derivative, colloidal silica and the like are known.

Generally, a dispersion of fine particles is called a colloid when the size of the fine particles is 0.1 μm or less, and an emulsion when the size of the fine particles is about several μm to 0.1 μm.

A dispersion liquid of such fine particles is already commercially available, and in this embodiment, an Ag 30 wt% independent dispersed particulate solution in which silver fine particles (manufactured by Shinku Yakin KK) is dispersed in a toluene solvent is used. The dispersed fine particles are produced by the evaporation method in a gaseous environment, and have a particle diameter of 0.1 µm or less, and are dispersed independently without aggregation of individual particles dispersed in a colloidal phase, so that the specific resistance of the solution is about 10 ⁷ It is high in cm. When the dispersion of these fine particles is discharged onto the member to be coated using electrostatic force, good stringing phenomenon occurs and discharge is possible.

Then, when the dispersion liquid discharged on the to-be-coated member is heated at 300 degreeC, a dispersion liquid will become the silver thin film which has an electrical conductivity. It is considered that this is because the surfactant or protective colloid covering the silver fine particles is dissolved by heat to evaporate and contact aggregation of the silver fine particles is achieved. Of course, this heating step may be omitted as described above in some cases.

As described above, even when the fine particles themselves have a property of low specific resistance, when the discharge solution is formed with the fine particles coated with the insulating material, the discharge solution can be discharged well by the electrostatic power to form a thin film, and the fine wiring can be directly Since the formation can be performed, a great effect can be obtained in reducing the cost of the circuit and wiring on the member to be coated having a curved surface.

Example 8

Hereinafter, an eighth embodiment of the present invention will be described. In the fourth to seventh embodiments, the case where only the electrostatic force is used as the means for discharging the solution has been described. In the eighth embodiment, when vibration by piezoelectric elements or the like is applied to the solution in addition to the electrostatic force, Explain.

FIG. 15 shows a configuration in which a solution is discharged using a nozzle that uses a combination of electrostatic force and pressure waves.

In Fig. 15, reference numeral 147 denotes a discharge port, reference numeral 148 denotes a piezoelectric element for generating pressure waves in a solution, reference numeral 149 denotes a pressure chamber, reference numeral 150 denotes a solution supply port, reference numeral 151 denotes a back electrode, 152 is a high voltage power supply, 153 is a member to be coated.

With this configuration, when a voltage is applied to the piezoelectric element 148, the piezoelectric element 148 is distorted and the volume of the pressure chamber 149 changes. The volume change of the pressure chamber 149 causes a flow in the solution in the discharge port 147, and when this flow is larger than the predetermined value, it becomes a solution drop and is discharged toward the member to be coated.

In addition, an electric field acts between the ink in the pressure chamber 149 and the back electrode 151, and exerts a force for sucking ink toward the to-be-coated member 153.

The discharge of the solution is performed when the electrostatic force is applied to the solution, or when both the pressure wave and the electrostatic force by the piezoelectric element 148 are present, and when no force is applied to the solution, the surface tension of the solution It is held in the discharge port 147.

FIG. 16 shows the results of examining the discharge of the solution in the case of electrostatic force only and in the case of using a pressure wave together using the above-described apparatus.

The curve shown in FIG. 16 is the result of connecting the discharge start point of the solution. When the pressure wave due to the piezoelectric effect is not applied to the solution, the electrostatic force at point C (at the electric field strength of 2 kV / mm in FIG. On the other hand, by applying a pressure wave to the solution, until the point D is reached, the larger the pressure wave, the smaller the electrostatic force can be.

In this case, the magnitude of the pressure wave applied to the solution varies depending on the material, size of the piezoelectric element, the shape of the liquid chamber, the nozzle diameter, and the physical properties of the discharged liquid, but is generally 50 V to 500 V as a voltage value applied to the piezoelectric element. It is enough. This experimental result shows that the discharge start voltage shown in FIG. 12 of the fourth embodiment is reduced by supplementally applying pressure waves to the electrostatic force as compared to the case where only the electrostatic force is applied to the solution as the method of discharging the solution. It is possible to generate a wide range of stringing phenomena.

This fact is further explained using FIG. 17. FIG. 17 shows the relationship between the resistivity of the solution and the applied voltage at the start of discharging when the electrostatic force indicated by the point E of FIG. 16 is applied to the solution and the pressure wave.

In Fig. 17, the broken line F indicates the discharge start voltage by only the electrostatic force (corresponding to curve A in Fig. 12), and the curve G shows the discharge start voltage by the constant power and the pressure wave. As the discharge means, the discharge start voltage of the solution can be lowered by applying a pressure wave to the electrostatic force, so that the region in the state where the solution causes the stringing phenomenon is added to the region of the portion d by the electrostatic force alone, and the portion e is added. It is also possible to use a solution having a low specific resistance, thereby making it possible to widen the choice of the discharge solution.

In addition, the process after discharge can be performed similarly to 4th Example, and can form a thin film.

As described above, when not only the electrostatic force but also the pressure wave is applied to the discharge solution, the type of the discharge solution can be selected more widely than the solution discharge method using only the constant power. It can have a huge effect on the fabrication of micromachines.

In the fourth to eighth embodiments, a method of discharging the solution in the stringing state has been described. However, the present invention is not limited thereto, and according to the predetermined state at the time of applying the solution, The specific resistance of the solution can be adjusted to form the droplet in the form shown or in the sprayed state shown in FIG. 10 (c).

In the above-described configuration of the present invention, there is practically no restriction on the kind of solution that can be used for discharging.

In addition, when the discharge solution is formed in a reliable stringing state, a fine thin film can be formed.

As described above, according to the present invention, a film is formed on a member to be formed by using a solution material as the film forming material and using the electrostatic force alone or the piezoelectric effect in addition to the electrostatic force as the discharge means of the film forming material. By discharging the solution of the material and heating the solvent contained in the solution or by evaporating by leaving it at room temperature for a predetermined time, there is no substantial restriction on the kind of the solution used for discharging, as compared with the conventional film forming method. When the solution is formed in the stringing state, it is possible to form a fine thin film, thereby providing a lot of convenience in the manufacture of various circuits and devices.

On the other hand, since the ink jet head may be configured such that the liquid is discharged by applying pressure outward from the liquid supply source toward the meniscus formed in the liquid discharge nozzle, in this case, an air discharge nozzle is provided on the opposite side of the liquid discharge nozzle. The air flow is directed at the gap between the liquid discharge nozzle and the air discharge nozzle, and the air pressure of the liquid discharge nozzle near the air discharge nozzle is set to be smaller than the air pressure applied to the meniscus formed at the liquid discharge nozzle from the liquid supply source. The liquid is burned in an air stream and discharged outward.

Example 9

Next, a ninth embodiment of the present invention will be described. 18 is a schematic structural diagram of a thin film forming method and a spin coater used in the apparatus according to the ninth embodiment of the present invention.

In Fig. 18, reference numeral 10 denotes a substrate to be coated, 161 an ink jet head, and 162 a nozzle.

Here, the ink jet head 161 refers to a form in which liquid is ejected through a micronozzle (generally 0.1 mm or less) and attached to a recording medium under the control of the liquid ejection state by an electric signal.

In addition, a plurality of nozzles 162 are formed at regular intervals in the radial direction of the rotating substrate to be coated 10. The thin film formation method by such a structure is demonstrated below.

First, for example, under the control of the personal computer 53 of FIG. 5, using the drive control mechanism similar to that of FIG. 5, the nozzle of the ink jet head 161 is rotated while rotating the substrate to be coated 10 at a low speed. At 162, the coating liquid 163 is discharged toward the substrate to be coated 10, and the coating liquid 163 is started to be attached onto the substrate to be coated 10.

Next, in general, the coating liquid 163 is rotated through the nozzles of the ink jet head 161 while the coating liquid 163 is rotated at a low speed until the coating liquid 163 adheres to the entire surface of the substrate to be coated 10. In 162, the liquid is continuously discharged toward the substrate 10 to be coated. That is, this low speed rotation is necessary to match the rotation speed sufficient to allow the coating liquid to adhere to the surface of the substrate to be coated 10.

In this case, when the pitch between the plurality of nozzles 162 is too wide and the lines of the coating liquid 163 formed by the adjacent nozzles 162 are separated from each other without overlapping, by the personal computer 53 of FIG. By rotating the coated substrate 10 a plurality of times at a low speed and moving the ink jet head 161 in the radial direction of the coated substrate 10, the coating liquid can be smoothly spread over the entire surface of the coated substrate 10. Attach.

Subsequently, under the control of the personal computer 53 of FIG. 5, after checking that the coating liquid is generally attached to the entire surface of the substrate to be coated 10, the substrate to be coated 10 is faster than the previous low speed rotation. It rotates, and blows the coating liquid apply | coated highly, and improves the uniformity of a coating film further. In this way, a thin film is formed on the substrate to be coated 10.

The discharge nozzles conventionally used in the spin coating machine are those having an internal diameter of 0.5 to 1 mm, and it is difficult to control the minute discharge amount. On the other hand, when the ink jet head 161 is used as in the ninth embodiment, a fine pattern is used. Can be formed and a uniform and extremely thin film can be formed.

Further, according to the ninth embodiment, since the coating liquid is applied to the entire surface of the substrate to be coated 10 by the ink jet head 161, the coating liquid that is scattered during the high speed rotation can be reduced in a small amount. This not only saves a lot of processing time but also saves running cost.

Example 10

Hereinafter, a tenth embodiment of the present invention will be described. 19 is a sectional view of the main parts of a spin coater, showing a detailed configuration example of the ink jet head used in the thin film forming method according to the tenth embodiment of the present invention.

In general, various types of systems can be used as the ink jet recording system. For example, a bubble jet system for generating bubbles with thermal energy and discharging liquid at the obtained pressure, and a pressure wave obtained by compressing the liquid chamber with a piezoelectric element. And a piezoelectric on-demand system for discharging a liquid. However, these systems have great limitations on the liquid that can be discharged, for example, as a usable liquid, the viscosity must be as small as 1 to 5 CP.

By using an ink jet head composed of a so-called electrostatic suction system as shown in FIG. 19, a relatively high viscosity (about 100 CP or less) discharge liquid can be used.

In FIG. 19, reference numeral 170 denotes a substrate to be coated, 171 denotes an ink jet head of an electrostatic suction system, 172 denotes a discharge nozzle, and 173 denotes an electrically conductive material such as a metal. It is a substrate holder. Reference numeral 174 denotes a high voltage generator, and 175 denotes a liquid chamber. The operation of the spin coater having such a configuration will be described below, but the thin film forming operation principle is the same as in the ninth embodiment.

First, the high voltage pulse is applied at a predetermined time period by the high voltage generator 174 between the substrate holder 173 and the liquid chamber 175 while rotating the to-be-applied substrate 170 at a low speed.

While the high voltage pulse is applied, the meniscus of the liquid formed in the discharge nozzle 172 is attracted and discharged toward the substrate fixing plate 173, whereby the liquid adheres to the substrate to be coated 170. In general, when the interval between the discharge nozzle 172 and the substrate fixing plate 173 is 2 to 3 mm, the liquid may be discharged at a voltage of about 2 to 4 kV.

The ink jet head of the electrostatic suction method can use a highly insulating organic solvent solution of about 100 CP or less, so that the polyimide liquid, the resist liquid, and the like can be discharged.

Subsequently, after checking that the coating liquid 177 is attached to the entire surface of the substrate to be coated 170, by rotating the coated substrate 170 at a higher speed than the previous low speed rotation, the excessively applied coating liquid is scattered. The uniformity of the coating film is further improved. That is, in this manner, a thin film is formed on the substrate to be coated 170.

In addition, in the tenth embodiment, finer patterns can be drawn than those of the conventional spin coater, and a uniform and very thin film can be formed. In addition, since the coating liquid 177 is applied to the entire surface of the substrate 170 to be coated by the ink jet head 171 using electrostatic force, the coating liquid that is scattered during high-speed rotation can be saved. Therefore, not only the running cost can be reduced but also the processing time can be greatly reduced. As the ink jet head, the ink jet head of the first embodiment can be used as shown in Figs.

Further, when the ink jet head used in the ninth and tenth embodiments is controlled by the solenoid valve 41 of FIG. 4, when a uniform thin film is formed on the object to be coated, as in the present invention, the high speed of the ink jet head The ink jet head has no problem in practical use without the need to draw a fine pattern even if the response drops.

Further, the method of the ninth and tenth embodiments in the form of simple pressure control is much more advantageous because the degree of freedom of the liquid that can be used is less affected by the physical properties of the liquid such as viscosity, surface tension and specific resistance.

Further, in the ninth and tenth embodiments, the substrate to be coated is positioned horizontally with the vertical axis held by the rotational axis, and the liquid is discharged from above. Of course, the present invention is so long as it can form a thin film having a predetermined characteristic. It is not limited only to.

As described above, according to the present invention, after adhering the coating liquid to the entire surface of the substrate while rotating the ink jet head and the substrate having a plurality of micronozzles at a relatively low speed, the substrate is rotated at a relatively high speed so as to be uniform. Obtain a coated thin film. Therefore, since the coating liquid which is scattered and wasted can be suppressed to the minimum, the running cost is low and the thin film formation method which can work at high speed can be provided. Moreover, by using the ink jet head, not only the fine patterns can be drawn, but also a very thin film can be formed more uniformly.

In this case, when the ink jet head of the electrostatic suction method is used, an organic solvent having a high insulating property of about 100 CP or less can be applied, and polyimide liquid, resist liquid and the like can also be discharged. In addition, the use of an ink jet head using air flow is less affected by the physical properties of the liquid such as viscosity, surface tension, and resistivity, so that the degree of freedom of the liquid that can be used is increased, which is more beneficial.

Example 11

22 is a perspective view of the film forming apparatus 301 according to the eleventh embodiment of the present invention.

In FIG. 22, the film forming apparatus 301 includes a substrate holding portion 303 and a substrate holding portion 303 which rotatably and suctionly hold an optical disk substrate (hereinafter referred to as substrate) 302 ( The discharge head 304 for discharging the coating liquid toward the 302, the liquid supply unit 305 for supplying the liquid to the discharge head 304, and the discharge head 304 in the radial direction from the center of the substrate 302 to move around. The control unit 307 controls the head moving unit 306, the substrate holding unit 303, the liquid supply unit 305, and the head moving unit 306.

The substrate holding part 303 has a disk-shaped, rotatable, substrate holding part 310 that sucks the substrate 302, and a substrate rotating motor 311 that rotates the substrate holding part 310. A cup 312 covering the periphery of the substrate 302 is provided to surround the substrate holding portion 303.

The discharge head 304 shown in FIG. 23 has, for example, seven nozzles 315a to 315g in the form of ink jet heads whose diameters gradually increase, and the nozzles 315a to 315g are formed. The pore diameter is determined by the area of application that increases from the periphery. The nozzles 315a to 315g are arranged in one row and one column. In addition, the nozzles may be arranged in the radial direction of the nozzle, or may be arranged to cross at a certain angle in the radial direction. In addition, since the application area is larger than the center side of the substrate 302, the nozzle 315a having the smallest diameter is disposed at the center side of the substrate 302, and the nozzle 315g having the largest diameter is disposed at the peripheral side. Do it.

The liquid supply part 305 is comprised by the fixed quantity discharge pump or pressurized airtight tank which can adjust discharge amount, for example. The liquid supply unit 305 supplies the discharge head 304 with a constant liquid discharge amount determined according to the coating area, the processing time, and the film thickness. The head moving part 306 moves the discharge head 304 in the radial direction of the substrate 302 between the starting position indicated by the solid line in FIG. 22 and the retracted position indicated by the two-dot chain lines. The head moving part 306 includes an arm 320 having a discharge head 304 attached to its tip, a moving frame 321, a pair of upper and lower guide bars 322, a holding frame 323, and a screw shaft 342. ) And a moving motor 325. The arm 320 has a pivot 320a for adjusting the installation position of the discharge head 304 with respect to the vertical axis in the middle thereof, and is attached to the movable arm 321 and the base end of the arm 320. The pair of upper and lower guide bars 322 moves the frame 321 horizontally, and the holding frame 323 holds both ends of the guide bar 322, and supports the screw shaft 324 rotationally. The screw shaft 324 is parallel to the guide bar 322 between the guide bar 322, the moving motor 325 is connected to one end. A guide bearing (not shown) slidably supported by the guide bar 322 is provided in the moving frame 321.

As shown in FIG. 24, the control unit 307 comprises a microcomputer including a CPU, a ROM, a RAM, and the like. The control unit 307 is connected to the liquid supply unit 305, the substrate rotation motor 311, the moving motor 35, and other input and output units, and also includes an input key 330 including a screw opening for starting operation, screw shaft ( Various sensors 331 including a sensor for detecting the rotational position of the 324 and the rotational speed of the substrate driver 311 are connected.

Next, the operation of the above-described embodiment will be described according to the flowchart shown in FIG.

Initial setting is performed in step S1 of FIG. During this initial setting, the head moving part 306 is in the retracted position as indicated by the dashed-dotted line, and in step S2, the substrate 302 is placed on the substrate holding table 310. waiting. When the substrate 302 is mounted on the substrate holding table 310, the program goes to step S3. In step S3, the discharge head 304 is brought to the starting position by the head moving part 306 as indicated by the solid line in FIG. 22. In step S4, when the substrate rotation motor 311 is turned on, the substrate 302 is fixed. Rotate at rotation speed. When the liquid supply part 305 is turned on in step S5, the liquid is discharged from the discharge head 304 to the substrate 302. Next, in step S6, the discharge head 304 moves at a constant speed toward the periphery of the substrate 302. In step S7, waiting for the discharge head 304 to reach the application end position, and when the discharge head 304 reaches the application end position, the program goes to step S8. In step S8, the substrate rotation motor 311, the moving motor 325, and the liquid supply part 305 are turned off. In step S9, since the substrate rotation motor 311 rotates at a high rotational speed, excess liquid is scattered. In step S10, the substrate release command is transmitted to the substrate transfer system provided separately, and the program flows to step S2.

In this case, the diameters of the nozzles 315a to 315g are configured to increase as the coating area increases. Therefore, the film having the most uniform film thickness can be formed through simple control of rotating the substrate 302 at a constant speed and moving the discharge head 304 at a constant speed.

According to the eleventh embodiment, the ink jet head is constituted by a nozzle, and the discharge amount of the liquid gradually increases in one direction, so that the discharge portion having the minimum discharge amount is a plurality of discharge portions arranged in the region near the substrate, The discharge amount of the discharged liquid gradually increases as it moves from the region side (center side) near the substrate to the region side (peripheral side) away from the substrate. Therefore, since the discharge amount is increased around the substrate having a large coating area, the film thickness can be made most uniform through simple control. In addition, by moving the ink jet head relative to the substrate, a thin film can be formed even when the substrate is one direction larger than the length of the liquid discharge portion. Moreover, only by gradually increasing the hole diameter of the nozzle, it is possible to easily increase the discharge amount as it moves toward the periphery of the substrate.

[Other Embodiments]

(a) As shown in FIG. 26, in the discharge head 404, for example, nine nozzles 435a to 435i of the same diameter are gradually narrowed as the application area is increased. Arrange.

In this case, the discharge amount can be easily increased by moving toward the periphery of the substrate only by gradually narrowing the arrangement pitch of the nozzles.

(b) As shown in FIG. 27, in the nozzle head 504, six sets of nozzle groups of the same diameter are arranged at equal intervals, and the number of nozzles of the nozzle groups 545a to 545f is applied. Increase with increasing. In this case, the nozzles are arranged so as to intersect the directions in which the nozzle groups are arranged, or the nozzles have a cylindrical shape.

In this case, the discharge amount can be easily increased only by gradually increasing the number of rows of each nozzle group and moving toward the periphery of the substrate.

(c) As shown in FIG. 28, the nozzle heads 615a to 615e are arranged at equal intervals in the discharge head 604, and the nozzles 615a to 615e are disposed in the discharge head 604. Place a thin edge orifice 636 to control the flow rate by gradually decreasing the pressure of the liquid supplied to it.

In this case, the thin-orifice orifice 636 acts as a flow rate control member for controlling the discharge amount of the nozzle, thereby gradually increasing the discharge amount toward the periphery of the substrate, thereby increasing the discharge amount toward the periphery of the substrate through simple control. Can be.

(d) Instead of moving the discharge head, the substrate holding portion is moved.

As described above, according to the present invention, since the discharge amount of the liquid discharged from the discharge portion is gradually increased as it moves from the center of the substrate to the periphery, the discharge amount is increased in the periphery where the coating area is large, so that the film thickness can be controlled through simple control. Can be made uniform.

Claims (31)

Ink jet heads 11, 70, 121, 124, 126, 133, 137, 161, 171, 190 having a plurality of nozzles for discharging liquid; Rotating means (50) for rotating the coated substrate (10) to which the liquid discharged from the ink jet head is attached about a rotating shaft; Relative moving means (51, 54) for relatively moving the ink jet head and the substrate to be coated between a region near the rotation axis with respect to the substrate to be coated and a separation region away from the rotation axis; Relative movement control means 52 for controlling the relative movement means such that the relative movement speed by the relative movement means decreases in response to the relative position between the ink jet head and the substrate to be coated moves relatively from the vicinity to the separation region. A thin film forming apparatus comprising 53). Ink jet heads 11, 70, 121, 124, 126, 133, 137, 161, 171, 190 having a plurality of nozzles for discharging liquid; Rotating means (50) for rotating the coated substrate (10) to which the liquid discharged from the ink jet head is attached about a rotating shaft; Relative moving means (51, 54) for relatively moving the ink jet head and the substrate to be coated between a region near the rotation axis with respect to the substrate to be coated and a separation region away from the rotation axis; Relative movement control means 52, 53 for controlling the relative movement means so that the rotational angular velocity by the rotation means decreases in response to the relative position of the ink jet head and the substrate to be coated relatively moved from the vicinity to the separation region. Thin film forming apparatus made up. The rotational angular velocity by the rotating means is small in response to the relative movement of the relative movement control means (52, 53) between the ink jet head and the substrate to be coated toward the separation region. Thin film forming apparatus, characterized in that for controlling the relative moving means. 4. The relative movement control means (52, 53) according to claim 3, wherein the relative movement control means (52, 53) increases the speed of relative movement in inverse proportion to the movement distance in which the relative position of the ink jet head and the substrate to be coated is relatively moved from the vicinity to the separation region. Thin film forming apparatus, characterized in that for deceleration. 5. The relative movement control means (52, 53) according to claim 4, wherein X is a moving distance at which the relative position between the ink jet head and the substrate to be coated moves relatively from the vicinity to the separation region, and V is the relative speed. In the formula V = K ₁ / X is maintained and K ₁ is greater than 0, the ink jet head and the substrate to be coated are relatively moved by the travel distance X measuring the other relative position Xe at the relative position Xs. When the required time is t, K ₁ is determined by solving the differential equation K ₁ = (ds / dt) * X. 4. An air outlet head (71) is further provided adjacent to the ink jet head (70) and for directing the air flow toward the substrate to be coated, whereby the air stream is discharged immediately after the liquid is discharged to the substrate to be coated. Thin film forming apparatus, characterized in that outflow to the substrate to be coated. The thin film forming apparatus according to claim 3, further comprising charging means (90) for charging the liquid discharged from the ink jet head. 4. The ink jet head according to claim 3, wherein the air jet outlets (25, 92) are provided to face the liquid discharge ports (27, 91), and the air flows out from the air discharge ports, so that the liquid pressure in the liquid discharge ports and the air flow are reduced. And discharging the liquid by varying the balance with the air pressure in the vicinity of the liquid discharge port. 9. The liquid discharged from the ink jet head according to claim 8, further comprising an electrode member (93) provided around the air discharge port, and a potential difference applying means (90) for applying a potential difference between the electrode member and the liquid in the liquid discharge port. Thin film forming apparatus, characterized in that for charging. The thin film forming apparatus according to claim 1, wherein the liquid discharged from the ink jet head is a non-quick dry resin solution. 4. The liquid discharged according to claim 3, wherein the liquid to be discharged is a solution material containing a film-forming material and a solvent for dissolving the film-forming material, wherein a supply source 143 for supplying the liquid to the nozzle and a substrate to be coated are placed and rotated. And a heating means (139) for heating the stage (140) rotated by the means and the substrate to be coated. 4. The apparatus according to claim 3, further comprising: first moving means (142, 142Z) for moving the ink jet head within a prescribed first direction connecting the ink jet head and the substrate to be coated with each other, and being disposed on the stage, And a second moving means (140, 140x, 140y) for moving the stage in two vertical directions in a vertical plane. The method of claim 3, wherein the liquid adhering to the surface of the substrate to be coated is rotated at a first relative speed sufficient to achieve the first application state by uniformly applying the surface of the substrate to be coated, and then excessively. The coated substrate is rotated at a second state speed higher than the first relative speed so that the applied coating liquid is scattered from the first application state to form a film of a second application state that is more uniform than the first application state. Thin film forming apparatus, characterized in that it further has a control means (53). The thin film forming apparatus according to claim 13, wherein the ink jet head is an electrostatic suction type ink jet head which sucks liquid to the outside of the nozzle by electrostatic force and discharges the liquid. The thin film forming apparatus according to claim 3, wherein the ink jet head is an electrostatic suction type ink jet head which sucks liquid to the outside of the nozzle by electrostatic force and discharges the liquid. 10. The method of claim 9 wherein the resistivity of the liquid is 10 ⁵ Thin film forming apparatus, characterized in that more than cm. The thin film forming apparatus according to claim 8, wherein the liquid is discharged in a string state. The thin film forming apparatus according to claim 3, wherein the liquid is discharged by applying pressure waves to the liquid. 4. The ink jet head according to claim 3, wherein the ink jet head comprises a nozzle and has a plurality of discharge portions arranged in one direction so that the discharge amount of liquid gradually increases in one direction, and the discharge portion of the minimum discharge amount is disposed near the substrate. Thin film forming apparatus, characterized in that. 20. The thin film forming apparatus according to claim 19, wherein the relative moving means moves the ink jet head toward the separation region of the substrate while the discharge port having the minimum discharge amount is disposed in the vicinity of the substrate. 20. The thin film forming apparatus according to claim 19, wherein the plurality of discharge portions are a plurality of nozzles arranged at equal intervals and whose diameter gradually increases toward the separation region. 20. The thin film forming apparatus according to claim 19, wherein the plurality of discharge portions are a plurality of nozzles having the same diameter and the array pitch gradually narrowing toward the separation region. 20. The thin film forming apparatus according to claim 19, wherein the plurality of discharge portions are a plurality of nozzle groups arranged at equal intervals and the number of nozzles gradually increasing toward the separation region. 20. The thin film forming apparatus according to claim 19, wherein the plurality of discharge portions comprises a plurality of nozzles having the same diameter arranged at equal intervals and a flow rate control member for controlling the discharge amount of the nozzles to gradually increase toward the separation region. . A rotating device for supporting and rotating the substrate about the rotating shaft; An ink jet head having a plurality of liquid discharge nozzles disposed to face a substrate supported by the rotating device; When the ink jet head is mounted in a substantially radial direction of the rotary device between the first region near the rotational axis and the outer peripheral portion of the substrate, the ink jet and the ink jet head are moved relative to the rotary device and the substrate. A moving device for moving one of the rotating devices with respect to the ink jet head and the other of the ink jet head; In response to the ink jet head moving from the center of the substrate to the outer periphery, a thin film is formed on a substrate including a control device for controlling the moving device and the rotating device such that the moving speed of the ink jet head or the rotating speed of the substrate is reduced. Forming device. 26. The apparatus of claim 25, wherein the plurality of discharge nozzles are disposed in a direction perpendicular to the moving direction of the head. A rotating device liquid reservoir for supporting and rotating the substrate about the rotating shaft; An air supply connected to an upper portion of the liquid reservoir for applying pressure to the liquid supply in the liquid reservoir; The liquid in the discharge port is supplied to the liquid reservoir so that a constant air flow is generated through the liquid discharge port to generate a pressure P ₂ near the liquid discharge port, and a pressure difference is generated at the liquid discharge port to discharge the liquid. Characterized in that it is under the pressure P ₁ by the air pressure, and the liquid inlet through the liquid reservoir, the air inlet through the air supply, the first plate formed with a plurality of liquid outlet and the spaced apart from the first plate An ink jet head having a second plate formed with a plurality of air discharge ports disposed so that each of the liquid discharge ports is concentric with the air discharge port; A moving device for moving one of the ink jet head and the rotating head device with respect to each other; A device for forming a film on a substrate comprising the moving device and a control device for controlling the rotating device. 28. The apparatus of claim 27, wherein the air inlet is in communication with a gap formed between the first plate and the second plate. A stable meniscus is formed at each of the liquid discharge ports when approximately equal balance is maintained between the pressure P ₂ and the pressure P ₁ so that the liquid in the liquid discharge port remains in the discharge port. An apparatus for forming a film on a substrate further comprising an air adjusting mechanism for adjusting the flow of air transferred from an air supply to the air inlet. 30. The air conditioner according to claim 29, wherein when air continues to flow through the air discharge port and surrounds the discharged liquid, the air regulating mechanism is operated such that the pressure P ₂ becomes smaller than the pressure P ₁ causing the liquid to be discharged through the liquid discharge port. And forming a film on the substrate, wherein the flow of air to the ink jet head air inlet is reduced. 28. The apparatus of claim 27, wherein the control device controls the moving device and the rotating device so that the moving speed of the ink jet head or the rotating speed of the substrate decreases in response to the ink jet head moving from the center of the substrate to the outer periphery. An apparatus for forming a film on a substrate, characterized in that.