KR20080079460A - Target apparatus for sputtering - Google Patents

Abstract

A target apparatus for sputtering is provided to maximize usage efficiency of a target by using an oxide target having a protrusion unit and ensure uniform deposition speed by curving the protrusion unit. A sputtering target apparatus comprises a magnetic field generator(400), a backing plate(500) and an oxide target(600). The backing plate is disposed on the magnetic field generator. The oxide target is disposed on the backing plate, and has a protrusion unit(640) protruded in correspondence with a magnetic field area formed by the magnetic field generator. The magnetic field generator includes at least one permanent magnet.

Description

Target device for sputtering {TARGET APPARATUS FOR SPUTTERING}

1 is a conceptual diagram for conceptually showing that a magnetic field is formed on an oxide target by a magnetic field generator.

FIG. 2 is a cross-sectional view taken along the line II ′ of FIG. 1.

3 is an exploded perspective view of a sputtering target device according to an embodiment of the present invention.

4 is a cross-sectional view taken along the line II-II 'of FIG. 3.

<Brief description of the symbols in the main drawings>

100, 400: magnetic field generator 120, 420: N pole

140, 440: S pole 200, 500: backing plate

300, 600: oxide target 320: magnetic field region

640: protrusion 660: flat portion

1000: sputtering target device

The present invention relates to a sputtering target apparatus, and more particularly, to a sputtering target apparatus that can maximize the use efficiency of the target without affecting the characteristics of the thin film compared to the generally used flat target.

In general, transparent electrodes (also known as transparent conductive films) include flat panel displays such as liquid crystal displays (LCDs), plasma display panels (PDPs), and electroluminescent displays (ELDs). It is used as an electrode material for batteries, and has a light transmittance of about 80% and a high electrical conductivity of ˜10 ³ / S · cm in the visible light region (400 nm to 700 nm). The transparent electrode includes tin oxide (SnO ₂ ) containing antimony (Sb) or fluorine (F) as a small amount of impurities, indium oxide (In ₂ O ₃ ) containing aluminum as a small amount of impurities, and aluminum (Al). Zinc oxide (ZnO) and the like containing a small amount of impurities are used. In particular, an indium oxide film containing tin as a small amount of impurities, i.e., an In ₂ O ₃ -SnO ₂ based film, is known as an ITO (Indium Tin Oxide) film. Since it has excellent adhesion with the substrate, it has been used a lot until now.

As a method of manufacturing the transparent electrode, sputtering, vacuum evaporation, plasma-assisted physical vapor deposition, and a method of applying a coating liquid for forming a transparent conductive layer are used. Among them, sputtering is widely used.

Sputtering physically impinges ions of sputter gas (usually argon gas) on a metal or compound target, and releases the material constituting the target with the collision energy, and the released material is deposited on the substrate. To be formed. Recently, sputtering is actively used, and sputtering using magnetron is generally used in consideration of sputtering efficiency, film formation speed, and thin film characteristics.

The principle of magnetron sputtering is to increase the density of the plasma applied to the target by attaching a permanent magnet to form a magnetic field perpendicular to the electric field to form a magnetic field on the target backside of the cathode. Constrain the movement of electrons around the target and extend the movement path to increase the sputter rate. Magnetron sputtering can operate at lower process pressures (10 ^-3 to 10 ^-4 Torr) compared to bipolar direct current sputtering. At this process pressure, the number of scattered particles is greatly reduced, so that the deposition rate is increased, and the thin film structure deposited on the substrate becomes more dense as the sputtered particles reach the substrate while maintaining the initial kinetic energy. In addition, the longer average free path allows the glow discharge to be maintained even at low target voltages (<~ 500 V) and high density plasma can be formed. This leads to a decrease in the target temperature, the formation of macroparticles is slowed down by the lower target temperature can improve the thin film flatness.

However, in magnetron sputtering, since plasma is concentrated in the formed magnetic field region, only a part of the target is sputtered and eroded, and the target is not consumed uniformly. That is, since only a portion of the target is eroded, there is a problem that the target must be discarded even though other portions of the target are not used. In addition, since more sputtering occurs where the line of magnetic force is close to a straight line, a problem arises in that a uniform deposition rate is not obtained at the target.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems as described above, and to provide a sputtering oxide target device having high use efficiency and uniform deposition rate.

According to an aspect of the present invention, a sputtering target device includes a magnetic field generator, a backing plate positioned on the magnetic field generator, and a protrusion located on the backing plate and protruding from the magnetic field region formed by the magnetic field generator. It includes the oxide target formed.

The magnetic field generating unit includes at least one permanent magnet.

It is preferable to use a flat plate made of a flat surface as the backing plate.

Protrusions of the oxide target are continuously formed along the magnetic field region. Therefore, when the magnetic field region is a closed curve shape, the protrusion also has a closed curve shape.

The protrusion of the oxide target has a curved surface, and the radius of curvature of the curved surface is 10 to 500 cm.

The oxide target includes a flat portion formed of a flat surface as a peripheral region of the protrusion and the protrusion, and a thickness ratio of the protrusion and the flat portion is 1: 0.9 to 0.1.

The area of the protrusions is at least 20% of the total area of the oxide target in plan view.

Oxide targets applied to the sputtering target apparatus are AZO target, ITO target and the like.

The sputtering target device may include a plurality of oxide targets.

Hereinafter, a sputtering target device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram for conceptually showing that a magnetic field is formed on an oxide target by a magnetic field generator. FIG. 2 is a cross-sectional view taken along the line II ′ of FIG. 1.

First, the magnetic field generating region will be described with reference to FIGS. 1 and 2. For convenience of description, it will be described by adopting the structure of the sputtering apparatus according to an embodiment of the present invention to be described later.

1 and 2, the sputtering target device includes a magnetic field generator 100, a backing plate 200, and an oxide target 300.

The magnetic field generating unit 100 includes a permanent magnet composed of the N pole 120 and the S pole 140, thereby forming the magnetic field region 320 on the backing plate 200 and the oxide target 300. To form. The magnetic field region 320 is intensively distributed between the N pole portion 120 and the S pole portion 140 in a plan view.

In the magnetron sputtering process, erosion mainly occurs in the portion of the oxide target 300 corresponding to the magnetic field region 320.

3 is an exploded perspective view of a sputtering target device according to an embodiment of the present invention. 4 is a cross-sectional view taken along the line II-II 'of FIG. 3.

3 and 4, the sputtering apparatus 1000 includes a magnetic field generator 400, a backing plate 500, and an oxide target 600.

As described above, the magnetic field generating unit 400 includes an N pole 420 and an S pole 440. When viewed in plan view, the N pole portion 420 is located at the center portion, and the S pole portion 440 is disposed around the N pole portion 420 spaced apart from the N pole portion 420 by a predetermined distance. In this embodiment, the S pole 440 forms a continuous closed curve.

In the present embodiment, the N pole portion 420 and the S pole portion 440 have a rectangular shape. However, it may alternatively have various shapes such as a circle.

In addition, by adjusting the separation distance between the N pole portion 420 and the S pole portion 440, the size of the magnetic field region 320 may be adjusted.

Although not shown, the magnetic field generating unit 400 may further include a cooling path for allowing a coolant to flow around the permanent magnet in order to cool the heat generated when sputtering, in addition to the permanent magnet.

The backing plate 500 is disposed on the magnetic field generating unit 300 and supports the oxide target 100. In addition, the backing plate 500 may be made of a metal material such as copper (Cu).

In this embodiment, the backing plate 500 has a flat surface.

The oxide target 600 is disposed on the backing plate 500. The oxide target 600 may be bonded to the backing plate 500 by a known method.

As the material of the oxide target 300, oxides such as indium tin oxide (ITO) series, tin oxide (SnO ₂ ) series, zinc oxide (ZnO) series, and magnesium oxide (MgO) series alone or the oxide may be Sn. Sintered together with other dopants such as Al, In, Ga, and B may be used, but the material of the oxide target 300 is not limited to the above materials.

Specifically, in this embodiment, an oxide target 600 such as ITO or AZO is bonded to one surface of the backing plate 500.

The oxide target 600 includes a magnetic field region (not shown) generated by the magnetic field generator 400. As described with reference to FIG. 1, the magnetic field region corresponds to a boundary region between the N pole portion 420 and the S pole portion 440. In this embodiment, the magnetic field region has a shape similar to a race track.

The magnetic field region is a variable region determined according to the shapes of the N pole portion 420 and the S pole portion 440 of the magnetic field generator 400.

The oxide target 600 corresponds to the magnetic field region and includes a protrusion 640 protruding from a surface by a predetermined thickness and a flat portion 660 which is a peripheral region except for the protrusion 640. The flat portion 660 has a flat surface unlike the protrusion.

In the present embodiment, since the protrusion 640 is formed corresponding to the magnetic field region, the protrusion 640 is continuously formed along the magnetic field region. That is, the protrusion 640 has a closed curve shape like a race track similar to the shape of the magnetic field region.

Accordingly, the flat portion 660 is divided into an inner flat portion confined by the protrusion 640 and an outer flat portion outside the protrusion 640.

Referring again to FIG. 4, the protrusion 640 of the oxide target 600 has a curved shape. That is, by having a shape similar to the pattern of the magnetic field lines in the magnetic field, it is possible to induce a uniform magnetic field effect on the surface of the protrusion 640, and obtain a uniform deposition rate from the oxide target 600.

The radius of curvature of the protrusion 640 of the oxide target 600 is 10 ~ 500cm, preferably 25 ~ 100cm.

The thickness ratio of the protrusion 640 and the flat portion 660 is 1: 0.9 to 0.1, preferably 1: 0.5 to 0.2. If the thickness of the flat portion 660 exceeds 90% of the thickness of the protrusion 640, the utilization efficiency of the oxide target 600 is significantly reduced, while the thickness of the flat portion 660 is the thickness of the protrusion 640. If the thickness is less than 10%, an arcing problem may occur at an interface between the protrusion 640 and the flat part 660, or the protrusion 640 may be out of the magnetic field region, and the sputtering efficiency may be drastically reduced at the protrusion 640. have.

The thickness of the protrusion 640 refers to a vertical distance from the bottom of the oxide target 600 to the highest point of the protrusion 640, and the thickness of the flat part 660 refers to the bottom of the oxide target 600. It refers to the vertical distance from the surface of the flat portion 660 to.

The planar area of the protrusion 640 of the oxide target 600 is preferably 20% or more relative to the total area of the oxide target 600 in consideration of the utilization efficiency of the oxide target 600.

Although the sputtering apparatus 1000 may include an integrated oxide target 600, the sputtering apparatus 1000 may alternatively include a plurality of oxide targets 600 divided into two or four quadrants. The plurality of oxide targets 600 are suitable for forming a large thin film.

As described above, the oxide target device for sputtering according to the present invention can maximize the use efficiency of the target by using the oxide target having a protrusion, and can ensure a uniform deposition rate by curving the protrusion.

As described above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

Claims (11)

Magnetic field generating unit; A backing plate positioned on the magnetic field generator; And And an oxide target disposed on the backing plate and having a protrusion formed to protrude corresponding to the magnetic field region formed by the magnetic field generating unit. The method of claim 1, The magnetic field generating unit includes at least one permanent magnet. The method of claim 1, The backing plate is a sputtering target device, characterized in that the flat. The method of claim 1, The projection of the oxide target is a sputtering target device, characterized in that formed continuously along the magnetic field region. The method of claim 1, A sputtering target device, characterized in that the protrusion of the oxide target has a curved surface. The method of claim 5, Sputtering target device, characterized in that the radius of curvature of the curved surface is 10 to 500cm. The method of claim 1, And the oxide target includes a flat portion formed of a flat surface as a periphery of the protrusion and the protrusion. The method of claim 7, wherein Sputtering target device, characterized in that the thickness ratio of the protrusion and the flat portion is 1: 0.9 to 0.1. The method of claim 1, The area of the protrusion is at least 20% of the total area of the oxide target when viewed in plan view. The method of claim 1, And the oxide target is an AZO target or an ITO target. The method of claim 1, The sputtering target device comprises a plurality of oxide targets.

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