JPH04140186A - Method and apparatus for transferring fine pattern - Google Patents

Abstract

PURPOSE:To accurately, sharply and efficiently transfer a fine pattern having fine line width and proper thickness while preventing adhesion inferiority by using a transfer substrate wherein a non-sticking transfer pattern is preliminarily formed on a substrate having flexibility and a sticking layer is formed thereon to perform transfer stationarily. CONSTITUTION:A transfer substrate 1 wherein a sticking layer 4 is provided on a non-sticking transfer pattern 3 is placed on a vacuum chuck table 20 to be held thereto in a reduced pressure state. An article 2 to be processed is mounted on a holder 10 to be held thereto. Compressed air is sent from a compressed air blowoff port 51 to pressurize the central part of the transfer substrate 1 by back pressure to closely bond the sticking layer 4 of the central part of the transfer substrate 1 to the article 2 to be processed. Next, the blowoff of compressed air is stopped and vacuum chuck table 20 is moved in the direction of the article 2 to be processed to bond the entire surface of the sticking layer under pressure. Continuously, the vacuum chuck table 20 is moved in the direction opposite to the direction opposed to the article 2 to be processed held to the work holder 10 to transfer the non-sticking transfer pattern to the article 2 to be processed from the outer peripheral part of the transfer substrate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fine pattern transfer method and a fine pattern transfer apparatus, and more specifically, for example, thin film transistors, thin film diodes, solar cells, thin film sensors,
A fine pattern transfer method that can efficiently transfer fine patterns onto functional workpieces such as various semiconductor elements and printed circuit boards with high dimensional accuracy and alignment accuracy, and a method that can be suitably used in this method. The present invention relates to a fine pattern transfer device. Further, the fine pattern transfer method and fine pattern transfer apparatus of the present invention include:
For example, it can be suitably used for transferring fine patterns in the manufacture of various sensors such as pressure sensors, color filters, thermal heads, color filters, pressure sensors, etc.

[Prior Art] For example, color liquid crystal displays (TPT-LCD) using thin film transistors are used in pocket TVs, portable TVs, and the like. And in recent years,
There is active development of large LCD flat displays such as 20 inches, 40 inches, and 70 inches.

This thin film transistor is usually manufactured by repeating the photolithography process about 4 to 6 times, that is, resist coating, exposure, development, and etching.

Further, for forming the fine pattern, it is also possible to use a printing method in which printing and etching of a resist pattern are repeated. When forming printed wiring or circuit patterns or forming resist patterns for etching metal plates, printing methods such as screen printing and offset printing are widely used.

[Problem to be solved by the invention] By the way, by repeating the above photolithography process, large TPT-LCs such as 40 inches and 70 inches can be manufactured.
In order to manufacture D, it is necessary to develop a dedicated device for use in the photolithography process, which requires a huge amount of cost. In particular, the development costs for large-scale exposure equipment are enormous.

On the other hand, if the above printing method is used to form fine patterns,
By repeating printing and etching of resist patterns, it is possible to relatively easily manufacture large TPT-LCDs such as 40 inches and 70 inches.

However, these printing means are only suitable for forming patterns with relatively large image lines (for example, 200 μm or more), and are not necessarily suitable for forming fine patterns with image line widths of less than 200 μm, for example. Moreover, in the printing method, the pattern is easily deformed (the printed pattern is It has the disadvantage of poor dimensional accuracy and reproducibility.

For example, in the screen printing method, an ink shielding mask is formed on a mesh-like screen, a desired pattern is formed on the non-masked portion of the shielding mask, and the ink is allowed to pass through the non-masked portion to adhere to the printing material. This is the way to do it. With this printing method, it is easy to print thick ink (generally several μm to 20 μm thick), so it is possible to print a resist pattern with excellent corrosion resistance.The practical printing width is limited to a minimum of about 200 μm. Forming fine patterns is difficult. In addition, the offset printing method uses a so-called PS plate (P+ET), which is a plate that has been sensitized in advance.
A lipophilic part and a hydrophilic part are formed on the en+i+1zed plate, and the hydrophilic part retains water and repels oil-based ink, thereby selectively adhering ink only to the lipophilic part, and covering the ink pattern. This is a method of printing on printed matter. In this method, the ink pattern on the plate is partially transferred to the rubber blanket and then retransferred to the printing material in order to particularly improve printing suitability. According to this printing method, relatively fine lines can be easily obtained. However, due to the dynamic inking method adopted in this method and the two transfer operations normally performed during this method, the printed ink film thickness is as small as about 1 μm, resulting in the print line being The disadvantage is that pinholes and wire breaks are likely to occur. Also,
Regarding this printing method, various efforts have been made to increase the ink film thickness and form fine patterns with excellent corrosion resistance, but as the film thickness increases, the printed lines become thicker.
The limit is printing with a line width of about 100 to 200 μm.

On the other hand, intaglio printing is known as a printing method that allows relatively thin lines and a large printed film thickness. In this method, printing recesses are formed by engraving or etching, hard, viscous ink is rubbed into the recesses, and after wiping off the ink in the non-printing areas, printing paper is placed on the copper plate. Print by applying strong pressure. The reason for applying such strong pressure is that the ink rubbed into the recesses is located at a recessed position below the plate surface.
This is because the ink surface is forcibly brought into contact with the printing surface by strongly pressing onto a flexible printed material such as paper, and the ink is transferred onto the printing surface. Therefore, with this intaglio printing method, it is difficult to print on highly rigid substrates, such as glass used for substrates of thin film semiconductor devices.

In addition, in all conventional printing methods, since the printing material and the transfer pattern are simultaneously pressed together over the entire surface of both, the phenomenon of air remaining between the printing material and the transfer pattern (so-called air pockets) may occur locally. Poor adhesion tends to occur, and the transferred pattern is often not transferred accurately.

The present invention has been made based on the above circumstances. That is, the present invention enables a fine pattern with a finer line width and appropriate film thickness to be formed accurately and clearly while preventing the occurrence of local adhesion failure due to the so-called air pockets, compared to conventional printing methods. It is an object of the present invention to provide a method for transferring a fine pattern that can be efficiently transferred, and a device for transferring a fine pattern that can be particularly suitably used in this method.

[Means for Solving the Problems] The gist of the present invention for solving the above problems is to form a transferable non-adhesive transfer pattern on a flexible substrate in advance, and then apply the non-adhesive transfer pattern. A transfer substrate is produced by forming an adhesive layer on the transfer pattern, and then the transfer substrate and the workpiece are held facing each other at a predetermined distance with the outer periphery of the transfer substrate in contact with a reduced pressure space. After aligning the transfer substrate and the workpiece, pressure is applied to the central portion of the transfer substrate from a surface opposite to the surface facing the workpiece, so that the central portion of the transfer substrate and the workpiece are aligned. By bringing the transfer substrate into close contact with the workpiece, then pressing the entire transfer substrate onto the workpiece, and then separating the transfer substrate and the workpiece from the outer peripheral side of the transfer substrate. A method for transferring a fine pattern, characterized in that the transfer pattern is transferred to the workpiece, and the method includes: a work holder that holds the workpiece; a vacuum chuck stand that holds a transfer substrate having a transfer pattern; an observation optical system that optically observes the positional relationship between the workpiece and the transfer substrate; and a workpiece-side register mark provided on the workpiece and a register mark provided on the transfer substrate based on the information obtained by the observation optical system. a flat plate moving mechanism that moves at least one of the work holder and the vacuum chuck stand to a position where the work holder and the pattern side register mark are observed to overlap with each other while maintaining a predetermined alignment gap, the vacuum chuck stand being a pressure-reduced space in contact with the outer periphery of the transfer substrate, and pressurizing a surface of the transfer substrate facing the workpiece sequentially from the center toward the peripheral edge thereof to the workpiece; This is a fine pattern transfer device characterized by being equipped with a mechanism.

[Function] In the fine pattern transfer method of the present invention, a transfer substrate is used in which a non-adhesive transfer pattern is previously formed on a flexible substrate and an adhesive layer is formed on the non-adhesive transfer pattern. However, the transfer is performed statically without using the viscosity of the transfer pattern itself. Therefore, for example, in dynamic transfer that utilizes the viscosity of printing ink to perform transfer onto a workpiece, problems arise due to the complex effects of various physical forces such as pressure force, sliding force, and bow tension force. Effects are eliminated and accurate transcription is achieved.

In addition, the transfer substrate and the workpiece are held facing each other at a predetermined distance with the outer periphery of the transfer substrate made of a flexible substrate in contact with a reduced pressure space, and the transfer substrate and the workpiece are held facing each other at a predetermined distance. After aligning with the object, pressure is applied to the central part of the transfer substrate from the surface opposite to the surface facing the workpiece, and the central part of the transfer substrate is pressed with the outer peripheral part remaining in contact with the depressurized space. The alignment accuracy is improved by bringing the transfer substrate into close contact with the workpiece, then pressing the entire transfer substrate onto the workpiece, and then separating the transfer substrate and the workpiece from the outer peripheral side of the transfer substrate. At the same time, the phenomenon in which air remains between the transfer substrate and the workpiece when they are in close contact with each other (so-called air pockets) is eliminated, thereby preventing the occurrence of local poor adhesion.

On the other hand, the fine pattern transfer apparatus of the present invention includes an observation optical system that optically observes the positional relationship between the transfer substrate and the workpiece, and a flat plate that moves at least one of the transfer substrate and the workpiece to a desired position. The moving unit moves at least one of the transfer substrate and the workpiece to a position where the workpiece-side register mark provided on the workpiece and the pattern-side register mark provided on the transfer substrate are observed to overlap, and transfers in that state. Since the substrate and the workpiece are pressed together, the alignment accuracy of the transfer pattern transferred to the workpiece is improved.

Furthermore, the transfer substrate and the workpiece are pressed together by bringing the outer periphery of the transfer substrate into contact with the reduced pressure space, so that the transfer substrate is placed and held on the vacuum chuck stand that holds the transfer substrate, and the workpiece is pressed against the transfer substrate. By applying pressure to the facing surface sequentially from the center to the peripheral edge using a pressure mechanism that can press the workpiece held in the work holder, air pockets can be eliminated and localized Prevents the occurrence of poor adhesion.

[Example] Hereinafter, a fine pattern transfer method and a fine pattern transfer apparatus of the present invention will be described with reference to the drawings.

FIG. 1 shows the relationship between the transfer substrate 1 and the workpiece 2. As shown in FIG.

As shown in FIG. 1(a), a transfer substrate 1 provided with a non-adhesive transfer pattern 3 and an adhesive layer 4 and a workpiece 2 are placed in a
They were placed facing each other with an alignment gap g of μm.

Here, the transfer substrate 1 is a stainless steel substrate with a thickness of 0.15 mrn coated with a water-soluble photosensitive liquid containing polyvinyl alcohol (PVA) and ammonium dichromate as main components, and then exposed using a mask with a predetermined shape. Then, it is developed to a thickness of 0. A masking layer 5 having a thickness of 5 μm and a line width of 5 μm was formed.

This masking layer 5 was subjected to a burning treatment to strengthen its water resistance and electrical insulation.

The non-adhesive transfer pattern 3 is formed by a nickel (Ni) plating layer with a thickness of 0.7 μm using an electrolytic plating method with the following bath composition and conditions, using a nickel (N1) plate as an anode and a stainless steel substrate as a cathode. Formed.

Bath Composition Nickel Sulfate Nickel Chloride Oxalic Acid Condition H Temperature Current Density 250 g/145 g/130 g/14.5 50°C 5 A/dm2 In this example, the material for forming the non-adhesive transfer pattern 3 was In addition to the nickel (N) used, for example, Cr, Fe
It is also possible to use various electrodeposition resists made of organic polymer materials such as , Ag, Au5Cu, Zn, Sn, compounds or alloys thereof, or epoxy resins, urethane resins, and acrylic resins.

The adhesive layer 4 was formed by applying a vinyl acetate-based adhesive solution to the entire surface of the non-adhesive transfer pattern 3 to a thickness of 0.3 μm.

Here, in this embodiment, the adhesive layer 4 is coated on the non-adhesive transfer pattern 3, but it is also possible to form the adhesive layer 4 on the workpiece 2.

In this example, the transfer substrate 1 produced as described above was placed and held on the vacuum chuck stand of the transfer apparatus of the present invention, as shown in FIG. 1(a).

Here, the fine pattern transfer apparatus of the present invention includes a work holder 10, a vacuum chuck stand 20, an observation optical system 30, and a flat plate moving mechanism 40, as shown in FIG. 2, for example.

The vacuum chuck stand 20 is, for example, as shown in FIG.
It is constructed using a surface plate 21, and is provided with a depressurized space 22 that can be depressurized by, for example, a vacuum pump on the surface opposite to the surface on which the transfer substrate 1 is placed.

A reduced pressure space communication hole 23 facing the surface on which the transfer substrate 1 is placed is formed in this reduced pressure space portion 22 . That is, when the pressure in the decompression space 22 is adjusted to reduce the pressure to a reduced pressure state, preferably to a vacuum state or a state close to it, the outer circumferential portion is placed on the surface plate 21 in a state where it is in contact with the reduced pressure space communication hole 23. The transfer substrate 1 is in a depressurized space 22 due to atmospheric pressure.
It is pressurized and held in the direction of . Further, the vacuum chuck stand 20 includes a pressurizing mechanism 50. This pressure mechanism 50
For example, as shown in FIG. 3, there is a compressed air blowing hole 51 provided so as to come into contact with the center of the transfer substrate 1 placed on the surface plate 21, and a compression pump 5 connected thereto.
2. That is, the transfer substrate 1 held by bringing the reduced pressure space 22 into a reduced pressure state
When compressed air is applied to the center of the transfer substrate 1 from the compressed air outlet 51, the center of the transfer substrate 1 is pressurized as shown in FIG. It comes into close contact with the surface to be processed of the workpiece 2 held on the work holder 10 with a distance therebetween.

The observation optical system 30 is capable of optically observing the positional relationship between the transfer substrate 1 and the workpiece 2, and includes, for example, a CCD camera 31, a microscope 32, and an epi-illumination device 3, as shown in FIG.
3. It can be configured using a CCU (electronic line generator) 34 and a TV monitor 35. It is preferable to provide two or more observation optical systems 3o. Observation optical system 3
By providing two or more systems of o, observation at multiple locations is possible at the same time. However, even if only one system of observation optical system 3o is provided, observation at multiple locations is possible if the observation optical system is movable.

As shown in FIG. 4, an alignment amount calculation section 36 is connected to the observation optical system 3o.

The alignment amount calculation unit 36 has a function of calculating the positional deviation between the pattern-side register mark provided on the transfer substrate 1 and the work-side register mark provided on the workpiece 2 based on the information obtained by the observation optical system 3°. have

As shown in FIG. 4, this alignment amount calculation section 36 can be configured using, for example, an input/output interface (Ilo), a control processing unit (CPU), and a random access memory (RAM).

The calculation result by the alignment amount calculation section 36 is outputted to the flat plate moving mechanism 40 as a control signal via the stage control section 37.

That is, the stage control unit 37 maintains a predetermined alignment gap between the pattern side register mark and the workpiece with respect to the positional relationship between the pattern side register mark and the workpiece side register mark in the secondary coordinate system (x-y coordinate system). A control signal necessary to move at least one of the work holder 10 and the vacuum chuck stand 20 to a position where the side register marks are observed to overlap is output to the flat plate moving mechanism 40.

The flat plate moving mechanism 40 provided on at least one of the work holder 10 and the vacuum chuck stand 20 can be configured using various motors such as a linear motor or a precision pulse motor.

In this example, using the transfer apparatus having the above configuration, the transfer substrate 1 was placed on the vacuum chuck table 20 as described above, and the transfer substrate 1 was held with the vacuum space 22 in a reduced pressure state.

On the other hand, the workpiece 2 was attached to and held by the work holder 10.

This workpiece 2 was formed by forming a p-8j (polysilicon) film to a thickness of 0.1 μm on a glass substrate.

Next, while optically observing the positional relationship between the transfer substrate 1 and the workpiece 2 on the TV monitor 35 of the observation optical system 30,
As shown in the figure, the vacuum chuck table 20 was moved by the flat plate moving mechanism 40 to a position where the pattern-side register mark 11 provided on the transfer substrate 1 and the work-side register mark 12 provided on the workpiece 2 overlapped.

Thereafter, compressed air is sent from the compressed air outlet 51 of the vacuum chuck 20 while the vacuum space 22 is in a vacuum state and the transfer substrate 1 is held, and the central part of the transfer substrate 1 is pressurized by back pressure. As shown in FIG. 1(b), the adhesive layer 4 at the center of the transfer substrate 1 was brought into close contact with the workpiece 2.

Next, the blowing of compressed air from the compressed air outlet 51 is stopped, and the vacuum chuck stand 20 is moved toward the workpiece 2 held by the work holder 10, as shown in FIG. 1(c).
As shown in FIG.
It was crimped. Note that it is also possible to perform this pressure bonding in an air chamber in a vacuum state. If the pressure bonding is performed in an air chamber in a vacuum state, the possibility of local adhesion failure due to the so-called air pockets described above can be further reduced.

Next, the vacuum chuck stand 20 is moved in the direction opposite to the direction in which it faces the workpiece 2 held on the work holder 10, and as shown in FIG. The adhesive transfer pattern 3 is transferred to the workpiece 2, and after the transfer is completed, the above steps are repeated to form the workpiece 2.
Multiple patterns were transferred to.

The transfer pattern transferred to this workpiece 2 has a line width of 1
Even in minute parts of about 0 μm or less, the film was accurate and clear, the film thickness was appropriate, and the alignment accuracy was excellent.

In this embodiment, a so-called parallel plate type printing method was adopted for the transfer, but the transfer method and transfer apparatus of the present invention can also be used in a so-called perpendicular plate type printing method.

[Effects of the Invention] According to the present invention, air remaining between the transfer substrate and the workpiece can be removed when they are brought into close contact with each other, thereby preventing local adhesion failure caused by so-called air pockets. At the same time, the non-adhesive transfer pattern itself is transferred to the workpiece via the adhesive layer after accurate positioning between the transfer substrate and the workpiece, resulting in a fine transfer pattern. To provide a method for transferring a fine pattern, which can be accurately transferred with high dimensional accuracy and reproducibility, and can be suitably adopted when, for example, a printing method is adopted to manufacture thin film semiconductor elements. Write.

Further, according to the present invention, since the observation optical system, the vacuum chuck stand, the flat plate moving mechanism, and the pressure device are provided, the transfer substrate and the workpiece can be accurately and easily aligned, and the workpiece can be It is possible to press the transfer substrate with the transfer substrate while eliminating any remaining air between the two, and it is possible to process clear fine patterns accurately with high alignment and dimensional accuracy, and with high reproducibility efficiently. It is an object of the present invention to provide a transfer device for fine patterns that can be transferred onto objects.

[Brief explanation of drawings]

1(a) to (d) are explanatory diagrams showing the relationship between the transfer substrate and the workpiece in the process order in the fine pattern transfer method of the present invention, and FIG. 2 is the configuration of the fine pattern transfer apparatus of the present invention. An explanatory diagram showing an example, FIG. 3 is an explanatory diagram schematically showing the configuration of a vacuum chuck in the fine pattern transfer device of the present invention, and FIG. 4 is an explanatory diagram showing the observation optical system and flat plate in the fine pattern transfer device of the present invention. FIG. 5 is an explanatory diagram showing an example of the relationship with the moving mechanism, and FIG. 5 is an explanatory diagram showing an example of information obtained as an image by the observation optical system in the fine pattern transfer apparatus of the present invention. DESCRIPTION OF SYMBOLS 1... Transfer substrate, 2... Workpiece, 3... Non-adhesive transfer pattern, 4... Adhesive layer, 10... Work holder 11 ・Pattern side register mark, 12...
- Work side register mark, 20... Decompression chuck stand, 22... Spatial space section, 30... Observation optical system, 4
0... Flat plate moving mechanism, 50... Pressure mechanism.

Claims (2)

[Claims] 1. A transferable non-adhesive transfer pattern is previously formed on a flexible substrate, and then an adhesive layer is formed on the non-adhesive transfer pattern to produce a transfer substrate, and then the outer periphery of the transfer substrate is The transfer substrate and the workpiece are held facing each other at a predetermined distance with the parts in contact with a depressurized space, and after aligning the transfer substrate and the workpiece, the central part of the transfer substrate is is pressed from a surface opposite to the surface facing the workpiece to bring the central part of the transfer substrate into close contact with the workpiece, and then the entire transfer substrate is pressed onto the workpiece. A method for transferring a fine pattern, characterized in that the transfer pattern is transferred to the workpiece by separating the transfer substrate and the workpiece from the outer peripheral side of the transfer substrate. 2. A work holder that holds a workpiece, a vacuum chuck stand that holds a transfer substrate having a transfer pattern, an observation optical system that optically observes the positional relationship between the workpiece and the transfer substrate, and the observation optical system. Based on the information obtained by the system, the workpiece-side register mark provided on the workpiece and the pattern-side register mark provided on the transfer substrate are observed to overlap while maintaining a predetermined alignment gap. a flat plate moving mechanism for moving at least one of a work holder and the vacuum chuck stand, the vacuum chuck stand having a vacuum space in contact with the outer periphery of the transfer substrate, and a space between the workpiece and the workpiece on the transfer substrate. 1. A micropattern transfer device comprising a pressing mechanism capable of pressing an opposing surface onto the workpiece sequentially from the center toward the peripheral edge.