KR100570980B1 - Sputtering apparatus - Google Patents

Abstract

The present invention relates to a sputtering apparatus for forming a thin film having a uniform thickness on a substrate, and in particular, a pair of targets facing each other at a predetermined distance and formed in a plasma in an internal space, and installed outside the target, A magnet formed to form a magnetic field perpendicular to the target surface, and a screen having a slit formed between the pair of targets and the substrate, the slit through which sputtering particles pass, wherein the slit has a width where the sputtering particles have a high density The density of this sputtering particle is narrower than the width of the low place.

Sputtering, screen, slit

Description

Sputtering Apparatus

1 is a cross-sectional view showing a first embodiment of a sputtering apparatus according to the present invention.

2, 3 and 4 are embodiments of the screen shown along the A-A plane in FIG.

5 is a graph showing the thickness of a thin film after depositing a thin film on a substrate using a sputtering apparatus without a screen and the sputtering apparatus with a screen according to the present invention.

6 is a perspective view showing a second embodiment of a sputtering apparatus according to the present invention.

7 is a cross-sectional view showing a third embodiment of the sputtering apparatus according to the present invention.

<Description of Signs of Major Parts of Drawings>

110a, 110b: target,

120a, 120b: magnet,

160: screen,

162: slit

The present invention relates to a sputtering apparatus, and more particularly to a sputtering apparatus for forming a uniform thickness thin film on the substrate.

As a method of forming a thin film on a substrate, there are chemical vapor deposition involving a chemical reaction and physical vapor deposition without a chemical reaction. Physical vapor deposition has a variety of methods such as sputtering, ion plating, etc., depending on the method of vaporizing the material. Sputtering is a phenomenon in which high energy particles (ions) collide with the surface of a solid, causing the particles to protrude from the surface of the solid. Sputtering is used to form a thin film on a substrate used for manufacturing a semiconductor device or a flat panel display. The sputtering device is called a sputtering device.

One of the flat panel displays is an organic light emitting display device. The organic light emitting display device is composed of a plurality of organic light emitting devices, and the organic light emitting display device has electrons and holes injected into the organic layer through a cathode and an anode. ) Recombine to form excitons, and light of a specific wavelength is generated by energy from the formed excitons.

The organic light emitting display device has a stacked structure of an anode, an organic layer, and a cathode on a substrate. The substrate is usually made of glass, but in some cases plastic or film types that can be bent are used. As the anode, a metal or an oxide having a large work function is used, and indium-tin-oxide (ITO) is used. The organic layer is composed of an electron transport layer (ETL), an organic emission layer (EML), a hole transport layer (HTL), and a separate electron injection layer (EIL) or hole injection. Sometimes a layer (Hole Injecting Layer) is inserted. As the cathode, a metal or oxide having a small work function is used, and magnesium or lithium is used.

Although there are various methods for depositing an electrode such as an anode or a cathode on a substrate, the chemical vapor deposition method causes metal oxides of the electrode material to be generated at the organic layer interface or inside the electrode to change electron injection characteristics and obtain desired device characteristics. Can't. Moreover, the adhesiveness of an electrode and an organic layer is bad, and peeling of an electrode arises, and it is difficult to manufacture a stable element. Therefore, sputtering apparatuses are mainly used to deposit both electrodes on a substrate in the manufacture of an organic light emitting display device.

U.S. Patent No. 6,596,138 and the like disclose a magnetron type sputtering apparatus. According to this document, a magnetron sputtering apparatus arranges a substrate and a target in parallel, forms a magnetic field parallel to the target surface by using a magnet provided under the target, and increases the density of the plasma by increasing the density of the sputtering. According to this method, however, the secondary electrons, electrons having high kinetic energy, etc. generated on the target surface collide with the organic layer and physically destroy the organic layer, thereby causing a problem that the characteristics of the organic light emitting device are not degraded or function.

Korean Patent Publication No. 2002-0087839 discloses a method for manufacturing an organic thin film device using a counter-target sputtering apparatus. In this document, a facing target type sputtering apparatus or a mirror shape target sputtering apparatus is a pair of targets facing in parallel with a predetermined space and a magnetic field generating a magnetic field in a direction substantially perpendicular to these target surfaces. Generating means and a shielding portion disposed so as to cover portions other than the opposing surface of the target. In this apparatus, the substrate is placed at a position opposite to the space between the targets and the power generated between the target and the shield is constrained to the space between the target surfaces to form a film on the substrate. According to this apparatus, the plasma region and the deposition region are completely separated, so that the substrate is hardly exposed to the plasma so that a thin film can be formed without damaging the organic layer. However, looking at the thickness of the thin film formed by the device, there is a problem that the thickness of the central portion of the substrate is relatively higher than the thickness of the edge portion, the overall thin film is not formed uniformly.

In addition, US Patent 6,689,253 proposed a method for improving the uniformity of the overall thin film by installing two pairs of opposing targets in duplicate. However, this has a problem in that the size of the equipment and the manufacturing cost are increased due to the installation of a further pair of opposing targets.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a sputtering apparatus capable of forming a thin film having a uniform thickness on a substrate in order to solve the above problems.

In order to solve the above technical problem, the present invention opposes a predetermined distance and has a pair of targets in which plasma is formed in an inner space and a magnetic field perpendicular to the target surface in an inner space of the target. It includes a magnet for forming and the screen is provided between the pair of target and the substrate is formed with a slit through which the sputtering particles pass.

Preferably, the magnet is a permanent magnet, and the screen is preferably disposed parallel to the direction of the magnetic field.

It is preferable that the width of the slit where the density of the sputtered particles is high is narrower than the width of the low density of the sputtered particles, and the slit preferably has at least one wider portion than the width of the center portion. . Alternatively, the slit may be wider at both ends than the width at the center portion.

The present invention also provides a pair of targets facing each other at a predetermined distance and having a plasma formed therein, and a magnet installed outside the target to form a magnetic field perpendicular to the target surface in the target space. It includes a vacuum vessel including the target and the magnet therein and formed with a slit through which sputtering particles pass through at least one surface.

Meanwhile, the present invention provides a sputtering apparatus in which a substrate and a target are disposed in parallel and a plasma is incident on the target surface to deposit sputtered particles from the surface of the target on the substrate, wherein the sputtering apparatus is provided between the target and the substrate. And a screen having slits through which the sputtered particles pass.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present embodiment is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments make the disclosure of the present invention complete, and the scope of the invention to those skilled in the art to the fullest extent. It is provided to inform you. Shapes of elements in the drawings may be exaggerated parts to emphasize more clear description, and the elements denoted by the same reference numerals in the drawings means the same elements.

1 is a cross-sectional view showing a first embodiment of a sputtering apparatus according to the present invention.

Referring to FIG. 1, the present embodiment includes a pair of targets 110a and 110b, a pair of magnets 120a and 120b, and a screen 160.

The pair of targets 110a and 110b are spaced apart from each other by a predetermined distance therebetween. Plasma is confined in the confining space 140 between the targets 110a and 110b. The targets 100a and 110b have a composition corresponding to the thin film to be formed on the substrate 150.

Magnets 120a and 120b are formed on outer surfaces of the targets 110a and 110b to form the magnetic field 130 around the confining space 140. The magnetic field 130 is formed in a direction perpendicular to the surfaces of the targets 110a and 110b. Accordingly, the magnetic poles of the magnet 120a provided on one target 110a and the magnet 120b provided on the other target 110b are reversed. Types of the magnets 120a and 120b use permanent magnets in this embodiment. However, electromagnets can be used as needed.

The substrate 150 is disposed at a position opposite to the restraint space 140 and is disposed in a direction parallel to the direction of the magnetic field 130, that is, perpendicular to the surfaces of the targets 110a and 110b.

According to the present embodiment, the plasma is formed in the confined space 140 between the targets 110a and 110b, and electrons having high kinetic energy among the particles protruding from the targets 110a and 110b by the plasma are formed in the magnetic field 130. Under the force of Lorentz, it is not possible to pop out of the confined space 140. Thus, only the desired sputtered particles pass through the magnetic field 130 and are deposited on the substrate 150.

However, the density of the sputtered particles exiting the magnetic field 130 is not constant and may not be adjusted. Therefore, in order to prevent a non-uniform thin film from being formed on the substrate 150 as a whole, a thin thin film is formed at the higher density of the sputtered particles and a thin thin film is formed at the lower density of the sputtered particles. The screen 160 is installed between the targets 110a and 100b and the substrate 150.

The screen 160 prevents sputtering particles protruding from the targets 110a and 110b on the substrate 160. However, one surface of the screen 160 forms a slit 162 through which sputtering particles can pass. That is, the sputtered particles pass through the slit 162 having a predetermined width to adjust the density of the sputtered particles deposited on the substrate 160.

The slit 162 is such that the width where the density of the sputtered particles is high is narrower than the width where the density of the sputtered particles is low. The density of the sputtered particles can be approximated by forming a thin film on the substrate 150 without the screen 160 and measuring the thickness of the thin film. That is, if the thickness of the formed thin film is high, the density of the sputtered particles is high, and if the thickness of the thin film is thin, the density of the sputtered particles is low. Therefore, where the density of the sputtered particles is high, the width of the slit 162 is reduced so that the particles do not pass well, and where the density is low, the width of the slit 162 is relatively large to allow the particles to pass well.

2, 3 and 4 are embodiments of the screen shown along the A-A plane in FIG.

2, the slit 212 formed on the screen 210 is formed to have a portion having a width wider than that of the central portion. That is, since the density of sputtering particles is usually high in the central portion, the width of the central portion of the slit 162 is narrowly formed and the width of other portions is widened.

Referring to FIG. 3, the slit 222 formed on the screen 220 may have a predetermined angle and become wider toward both ends from the center of the slit 222. In addition, referring to Figure 4, while forming a constant width in the center of the slit 232 is wide at both ends. As such, when the slit 232 is formed to have a wider width at both ends than the central portion, a uniform thin film can be obtained by making the density of the sputtered particles deposited on the substrate 150 uniform.

In addition to the above examples, the slits may be formed to have a vertical shape instead of the horizontal shape shown in FIGS. 2 to 4, and a plurality of slits may be formed on the screen 160 to adjust the density of the sputtered particles.

Hereinafter, the operation of this embodiment will be described with reference to FIG. 1.

Argon gas is injected into a vacuum chamber (not shown) in which targets 110a and 110b are installed. When targets 110a and 100b are used as cathodes and vacuum chambers are used as anodes, the power unit (not shown) applies power, and argon gas becomes plasma, and targets 110a and 110b are used. Sputtering particles pop out from the surface.

The polar particles are constrained in the confinement space 140 by the magnetic field 130 and the desired sputtered particles pass through the slit 162 of the screen 160 and are deposited on the substrate 150. At this time, since the width of the slit 162 where the density of the sputtering particles is high is narrow, the density of the sputtering particles reaching the substrate 150 is somewhat uniform. Therefore, a thin film of uniform thickness is formed on the substrate 150.

5 is a graph showing the thickness of a thin film after depositing a thin film on a substrate using a sputtering apparatus without a screen and the sputtering apparatus with a screen according to the present invention. The working pressure was 1 mTorr to 20 mTorr and an aluminum (Al) metal thin film was deposited on the substrate by applying a DC power of about 1000 W. The screen used the shape shown in FIG.

The X axis represents a straight line coordinate on the substrate, and a point about 250 mm becomes the center of the substrate. The Y axis is expressed as a percentage by converting the measured thickness of the thin film into an error value with respect to the average value.

Referring to FIG. 5, in the absence of a screen, the thickness of the center portion is thicker than the thickness of both ends, and the difference is about ± 30%. However, when the screen in which the slit is formed is arranged, the thickness difference between the center and both ends is only ± 7% or less. Therefore, according to the present invention, a thin film of even uniform thickness can be formed on the substrate.

6 is a perspective view showing a second embodiment of a sputtering apparatus according to the present invention.

Referring to FIG. 6, a pair of target parts 520a and 520b are disposed to face each other in the vacuum container 500. The target units 520a and 520b include a target (not shown) and a magnet (not shown), which are the same as in the first embodiment.

The vacuum vessel 500 has a structure in which the inside is sealed, and the magnetic field formed by the target portions 520a and 520b is formed along the inner circumference of the vacuum vessel 500 in the Z-axis direction.

A slit 510 is formed on the surface 500a of the vacuum container 500 corresponding to the substrate 550. Sputtered particles are deposited on the needle and the substrate 550 through the slit 510 to the outside of the vacuum vessel 500. Matters on the shape of the slit 510 are the same as those of the first embodiment.

In the present embodiment, the number of slits 510 is not limited. If the substrate 550 is installed corresponding to the other surface 500b of the vacuum vessel 500, the slit 510 may be formed on the surface 500b. In other words, according to the present embodiment, since a plurality of substrates may be installed around the vacuum container 500 and a thin film may be formed at the same time, productivity of the product may be improved.

Since the operation of this embodiment is the same as that of the first embodiment, description thereof will be omitted.

7 is a cross-sectional view showing a third embodiment of the sputtering apparatus according to the present invention.

Referring to FIG. 7, a screen 630 in which a slit 632 is formed between the target 600 and the substrate 620 is installed in a sputtering apparatus in which the target 600 and the substrate 620 are disposed in parallel to each other. do.

The surface of the screen 630 is disposed parallel to the surface of the substrate 620, and the structure of the screen 630 and the slit 632 is the same as that of the first embodiment.

In other words, in the first and second embodiments described above, an example of the counter-target sputtering apparatus in which a pair of targets are provided opposite to each other is shown, but the present invention is also applied to the sputtering apparatus in which the substrate and the target are arranged in parallel. Is possible. An example of the structure and operation of such a sputtering apparatus is shown in US Pat. No. 6,596,138 and the like, and a description thereof will be omitted.

As described above, according to the present invention, a thin film having a uniform thickness can be formed on the substrate. Therefore, product quality and productivity can be improved.

In addition, according to the present invention, the electrode or the organic layer of the organic light emitting diode can be uniformly formed on the substrate at low temperature, thereby improving the quality of the organic light emitting display device.

Claims (16)

A pair of targets facing each other at a predetermined distance and having a plasma formed therein; A magnet installed outside the target to form a magnetic field perpendicular to the target surface in an inner space of the target; And And a screen having a slit formed between the pair of targets and the substrate to allow the sputtered particles to pass therethrough. The method of claim 1, Sputtering apparatus, characterized in that the magnet is a permanent magnet. The method of claim 1, And the screen is disposed parallel to the direction of the magnetic field. The method of claim 1, And wherein the slit has a narrower width at a location where the density of the sputtered particles is higher than a width at a location where the density of the sputtered particles is low. The method of claim 1, The slit has a sputtering device, characterized in that at least one portion wider than the width of the center portion. The method of claim 1, The slit is a sputtering device, characterized in that the width of both ends is wider than the width of the center. A pair of targets facing each other at a predetermined distance and having a plasma formed therein; A magnet installed outside the target to form a magnetic field perpendicular to the target surface in an inner space of the target; And And a vacuum vessel including the target and the magnet therein and having a slit formed therein with at least one surface through which sputtering particles pass. The method of claim 7, wherein Sputtering apparatus, characterized in that the magnet is a permanent magnet. The method of claim 7, wherein And wherein the slit has a narrower width at a location where the density of the sputtered particles is higher than a width at a location where the density of the sputtered particles is low. The method of claim 7, wherein The slit has a sputtering device, characterized in that at least one portion wider than the width of the center portion. The method of claim 7, wherein The slit is a sputtering device, characterized in that the width of both ends is wider than the width of the center. A sputtering apparatus in which a substrate and a target are disposed in parallel and a plasma is incident on the target surface to deposit sputtered particles coming from the surface of the target on the substrate. And a screen disposed between the target and the substrate, the screen having slits through which the sputtering particles pass. The method of claim 12, Sputtering device, characterized in that the surface of the screen is parallel to the surface of the substrate. The method of claim 12, And wherein the slit has a narrower width at a location where the density of the sputtered particles is higher than a width at a location where the density of the sputtered particles is low. The method of claim 12, The slit has a sputtering device, characterized in that at least one portion wider than the width of the center portion. The method of claim 12, The slit is a sputtering device, characterized in that the width of both ends is wider than the width of the center.

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