KR20110087082A - Method of manufacturing a plasma display panel filter and dc sputtering device employed in the same - Google Patents

Abstract

PURPOSE: A method for manufacturing a plasma display panel filter and a DC sputtering device for the same are provided to prevent the formation of a separate oxide layer between a high refractive transparent layer and a metal layer because the conductivity of the corresponding metal layer does not degrade due to oxygen. CONSTITUTION: A DC sputtering device for a plasma display panel filter comprises a substrate holder, a back panel, shields(308a,308b), and a DC power supply unit(310). The substrate holder fixes a substrate(306). The back panel supports a specific target arranged facing the substrate. The shields are arranged outside the target and have recesses to prevent the shield from becoming non-conductive. The DC power supply unit applies voltage to the target(302) and the shields, and the DC power supply comprises a DC power supply(320) generating specific DC voltage and a division control part(322) changing the DC voltage into pulses and distributing the pulses.

Description

METHOD OF MANUFACTURING A PLASMA DISPLAY PANEL FILTER AND DC SPUTTERING DEVICE EMPLOYED IN THE SAME}

The present invention relates to a method for manufacturing a plasma display panel (PDP) filter and a direct current sputtering apparatus used therein, and more particularly, to a method for manufacturing a PDP filter using a TiO _X target and a direct current including a shield in which recesses are formed to prevent insulatorization. It relates to a sputtering device.

Plasma Display Panels (PDPs) are widely used display devices and emit electromagnetic waves and near infrared rays due to their technical characteristics. Therefore, in order to block such electromagnetic waves, a PDP filter having a structure as shown in FIG. 1 below is attached to the PDP panel.

1 is a cross-sectional view showing a general PDP filter.

Referring to FIG. 1, a PDP filter may include a transparent substrate 100, a first repeating film 102-1, a second repeating film 102-2, and a second high refractive index thin film layer Nb ₂ O ₅ , 104 sequentially formed. )

The first repeating film 102-1 is formed on the transparent substrate 100, and the first-refractive refractive thin film layers Nb ₂ O ₅ and 110-1 and the first-first oxide layer ITO 112-1 are formed. , 1-1 metal thin film layers (Ag, 114-1) and 2-1 oxide layers (ITO, 116-1).

The second repeating film 102-2 is formed on the 2-1 oxide layer 116-1, the 1-2 high refractive index thin film layers Nb ₂ O ₅ , 110-2, and the 1-2 oxide layer ( ITO, 112-2), 1-2 metal thin film layers (Ag, 114-2) and 2-2 oxide layers (ITO, 116-2).

In the PDP filter having such a structure, a sputtering process is used during the formation of the high refractive index transparent film layer 110-2 or 104, and a large amount of oxygen gas is used in this process. Here, when the oxide layer 116-1 or 116-2 is not formed, a large amount of oxygen gas is in direct contact with the metal thin film layer 114-1 or 114-2 and the metal thin film layer 114-1 or 114- The electrical conductivity of 2) may be degraded.

Therefore, the conventional PDP filter forms the second oxide layer 116-1 or 116-2 between the high refractive index transparent film layer 110-2 or 104 and the metal thin film layer 114-1 or 114-2 to form the oxygen. It prevents the electrical conductivity deterioration of the metal thin film layer 114-1 or 114-2 by a gas.

That is, in order to prevent deterioration of the electrical conductivity of the metal thin film layer 114-1 or 114-2, the second oxide layer 116-1 or 116-2 is necessary. As a result, the thickness of the PDP filter is thick. Inevitably, the light transmittance of the PDP filter may be reduced, and manufacturing cost and manufacturing process time may be increased.

In terms of the sputtering apparatus, when a plurality of PDP filters are manufactured, the target material is attached to the inner wall and the shield of the chamber. That is, when the deposition process is performed for a long time, a target material is attached to the shield, so that the shield may be changed to a non-conductor. In this case, since the shield replacement or cleaning process should be performed, productivity of the PDP filter may be reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a PDP filter manufacturing method and a direct current sputtering apparatus used therein, which improves the deposition rate and prevents the insulator of the shield to improve the productivity of the PDP filter.

In order to achieve the above object, a direct current sputtering apparatus according to an embodiment of the present invention comprises a substrate holder for fixing a substrate; A back plate supporting a specific target arranged at a position opposite the substrate; And at least one shield arranged outside the target. Here, at least one recess is formed in a part of the shield to prevent insulatorization of the shield.

In the PDP filter manufacturing method according to an embodiment of the present invention, a pulsed DC power is supplied to at least one shield inside the chamber, and a specific DC power is supplied to a TiO _X (x = 1.5 to 1.99) target to inert in the chamber. Plasmalizing the gas; And sputtering the TiO _X target through the plasmalized inert gas ions to deposit a high refractive index transparent thin film layer formed of TiO ₂ on a substrate. Here, at least one recess is formed in a part of the shield to prevent insulatorization.

Since the high refractive index transparent thin film layer of the PDP filter according to the embodiment of the present invention is deposited in a small amount of oxygen atmosphere by using a TiO _X (x = 1.5 to 1.99) target, the electrical conductivity of the metal thin film layer is deteriorated due to the oxygen gas. Therefore, a separate oxide layer may not be formed between the high refractive index transparent thin film layer and the metal layer. As a result, the thickness of the PDP filter can be reduced, so that the light transmittance is improved, and the manufacturing cost and manufacturing time of the PDP filter can be reduced.

In addition, since the high refractive index thin film layer is manufactured through a pulsed DC sputtering process, the deposition process may be stably performed without any arcing while improving the deposition rate. In particular, since a recess is formed in a part of the shield included in the sputtering apparatus, the non-conducting of the shield may be prevented or progressed slowly, thereby improving the productivity of the PDP filter.

1 is a cross-sectional view showing a general PDP filter.
2 is a cross-sectional view showing a PDP filter according to an embodiment of the present invention.
3 is a diagram illustrating a process of forming a high refractive index transparent thin film layer through a pulse direct current sputtering process according to an embodiment of the present invention.
4 is a diagram illustrating a waveform of a voltage applied to a shield.
5 is a cross-sectional view showing the termination structure (A) of the shield according to an embodiment of the present invention.
6 is a cross-sectional view illustrating a PDP filter including four metal thin layers according to an embodiment of the present invention.
FIG. 7 is a diagram illustrating a light transmittance graph of the PDP filter of FIG. 6.
8 is a cross-sectional view showing a PDP filter according to another embodiment of the present invention.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a cross-sectional view showing a PDP filter according to an embodiment of the present invention.

Referring to FIG. 2, the PDP filter according to the present embodiment is an element that blocks electromagnetic waves and near infrared rays generated from a PDP panel, and includes a transparent substrate 200, at least one repeating film 202, and a second high refractive index transparent array. The thin film layer 204 is included.

The transparent substrate 200 is made of a material having excellent transmittance to visible light, for example, a plastic film layer such as polyethylene terephthalate (PET), a plastic sheet made of acrylic resin, or the like used for display Semi-tempered glass; The transparent substrate 200 has a visible light transmittance of 80% or more, and preferably has heat resistance.

The repeating film 202 is a film that substantially blocks electromagnetic waves, near infrared rays, and the like, and is arranged on the transparent substrate 200. However, a plurality of repeating layers 202, for example four repeating layers 202, may be sequentially arranged on the transparent substrate 200.

According to one embodiment of the present invention, one repeating film 202 includes a first high refractive index transparent thin film layer 210, an oxide layer 212 and a metal thin film layer 214.

The first high refractive index transparent thin film layer 210 is arranged on the transparent substrate 200 and is made of an oxide having high refractive index and excellent transmittance to visible light. Preferably, the first high refractive index transparent thin film layer 210 is made of titanium dioxide (TiO ₂ ), which exists a lot on the earth and is inexpensive and has excellent optical properties. Here, TiO ₂ is a material having three crystal forms of rutile, anatase, and broookite, and has high transmittance characteristics in the visible and infrared regions.

Of course, the first high refractive transparent thin film layer 210 is not limited to TiO ₂ as long as it has high refractive characteristics and high transparency, but may be made of a material such as Nb ₂ o ₅ , SnO ₂ , but as described below, a pulsed DC sputtering process And TiO ₂ in consideration of both optical characteristics and the like.

According to an embodiment of the present invention, the first high refractive index transparent thin film layer 210 formed of TiO ₂ may have a thickness of about 10 nm to about 35 nm, and an oxide target, preferably TiO _X (x = 1.5 to 1.99) using the target can be deposited on the substrate 100 or the second high refractive index transparent thin film layer 204, which is the previous film. In particular, the first high refractive index transparent thin film layer 210 may be formed through a pulsed DC sputtering process in a low oxygen atmosphere, in which case the first high refractive index transparent thin film layer 210 having a high surface hardness and a dense surface may be formed. Can be. Detailed description thereof will be described later.

The oxide layer 212 is made of a material having a predetermined refractive index difference from the metal thin film layer 214, and the visible light reflection of the metal thin film layer 214 may be prevented according to the difference in refractive index. In addition, since the light must be well transmitted, the oxide layer 212 may be formed of a material having high transparency to visible light, for example, a metal oxide such as indium, titanium, zirconium, aluminum, tin, zinc, or a mixture of these metal oxides. Can be done.

According to an embodiment of the present invention, the oxide layer 212 may be made of AZO or ITO having a high film forming speed and excellent adhesion to the metal thin film layer 214. However, since the production cost of indium (In), which is a raw material of ITO, is high and deteriorated when exposed to plasma, AZO is used as the material of the oxide layer 212 because it is inexpensive and has excellent durability against plasma. It is preferable.

The oxide layer 212 may have a thickness of about 3 nm to about 7 nm, which is thinner than the first high refractive index transparent thin film layer 210.

The metal thin film layer 214 is electrically connected to a cover (not shown), which serves as a ground, to block electromagnetic waves generated from the PDP panel, and is made of silver (Ag) or an alloy containing silver having excellent conductivity. That is, electromagnetic waves generated from the PDP panel are discharged to the cover through the metal thin film layer 214. According to an embodiment of the present invention, the metal thin film layer 214 may have a thickness of about 10 nm to about 13 nm.

The second high refractive index transparent thin film layer 204 is formed on the metal thin film layer 214 and may be made of TiO ₂ . According to one embodiment of the invention, the second high refractive index transparent thin film layer 204 made of TiO ₂ is formed using a TiO _X (x = 1.5 ~ 1.99) target, in particular to be formed in a low oxygen atmosphere through a pulsed DC sputtering process Can be. As a result, a separate oxide layer is not required between the metal thin film layer 214 and the second high refractive transparent thin film layer 204 as described later.

The second high refractive index transparent thin film layer 204 may have a thickness of about 10 nm to about 35 nm.

Hereinafter, the process of forming a high refractive index transparent thin film layer of this invention and the process of forming a conventional high refractive index transparent thin film layer are compared.

In the process of manufacturing a conventional PDP filter, a large amount of oxygen gas was used during the coating of the high refractive index transparent thin film layer (Nb ₂ O ₅ ), and as a result, the electrical conductivity of the metal thin film layer (Ag) may be degraded due to the oxygen gas. Before forming the high refractive transparent thin film layer Nb ₂ O ₅ , an oxide layer ITO is further formed on the metal thin film layer Ag. That is, an oxide layer ITO is formed between the metal thin film layer and the high refractive transparent thin film layer Nb ₂ O ₅ so that the oxygen gas does not directly contact the metal thin film layer.

On the other hand, in the process of manufacturing the PDP filter of the present invention, a target that maintains an oxidized state but has a conductivity level that is electrically conductive, that is, a TiO _X (x = 1.5 to 1.99) target is used, and as a result, The second high refractive index transparent thin film layer 204 can be formed even if only a small amount of oxygen gas is added without introducing oxygen gas. Specifically, when the conventional high refractive index transparent film layer is formed, argon gas and oxygen gas are respectively used at about 200 sccm, whereas when the second high refractive index transparent film layer 204 is formed, the oxygen is used when about 200 sccm is used. Only about 5 sccm of gas (about 2.5% of argon) is used. In other words, in the prior art, about 200 sccm of oxygen gas is required, while in the present invention, only about 5 sccm of oxygen gas is required. Here, even if the oxygen gas of about 5 sccm is in direct contact with the second high refractive transparent thin film layer 204, the electrical conductivity of the metal thin film layer Ag may hardly deteriorate. Therefore, unlike the prior art, a separate oxide layer is not required between the metal thin film layer 214 and the second high refractive index transparent thin film layer 204. In particular, since the amount of oxygen gas used when using a TiO _X (x = 1.5 to 1.99) target is significantly smaller than that when using a high refractive material such as Nb ₂ o ₅ , the electrical conductivity of the metal thin film layer (Ag) is better. Can be maintained.

In the above, although the TiO _X (x = 1.5 to 1.99) target was used to form the second high refractive transparent thin film layer 204, a TiO ₂ target may be used instead. However, when the TiO ₂ target, it can be when the power applied to the TiO ₂ target a highly arcing (arcing) because it has caused a TiO ₂ target with the high resistance, that is, low conductivity properties. Therefore, to be kept low, the power applied to the TiO ₂ target using a TiO ₂ target, and this causes to slow the evaporation rate. In addition, when using a TiO ₂ target, a large amount of oxygen gas is required. Therefore, in consideration of the deposition rate and the amount of oxygen gas, it is preferable to use a TiO _X (x = 1.5 to 1.99) target when forming the second high refractive index transparent thin film layer 204.

In short, the PDP filter of the present invention forms a high refractive transparent thin film layer 210 or 204 using a TiO _X (x = 1.5 to 1.99) target. As a result, a separate oxide layer does not need to be formed between the immediately preceding metal thin film layer 214 and the second high refractive index transparent thin film layer 204. Therefore, the thickness of the PDP filter of the present invention can be formed thinner than the conventional PDP filter, and as a result, the light transmittance of the PDP filter can be improved. In addition, since no additional oxide layer is required, not only the target cost, that is, the manufacturing cost, but also the deposition process can be simplified.

In the above description, the TiO _X (x = 1.5 to 1.99) target is also used to form the first high refractive index transparent thin film layer 210 on the transparent substrate 200. However, since the metal thin film layer to be degraded is not formed, the TiO ₂ target is used. Or the like may be used. However, in general, since a plurality of high refractive index transparent thin films will be formed in one chamber for mass production, even when the first high refractive index transparent thin film layer 210 is deposited on the transparent substrate 200 to maintain a low oxygen atmosphere, TiO _X (x = 1.5 ~ 1.99) It is preferable to use a target.

In FIG. 2, only one repeating film 202 is illustrated, but a plurality of repeating films 202 may be sequentially arranged on the transparent substrate 200. Even in this case, a TiO _X (x = 1.5 to 1.99) target is used to form the high refractive transparent thin film layer, and thus, a separate oxide layer is not formed between the high refractive transparent thin film layer and the lower metal thin film layer in the repeating film 202. Can be.

According to an embodiment of the present invention, some of the high refractive index transparent thin film layers of the repeating layers 202 may have a thickness different from that of the other high refractive index thin film layer or the second high refractive index transparent thin film layer 204 in consideration of reflection characteristics. Detailed description thereof will be described later with reference to the accompanying drawings.

According to one embodiment of the present invention, a pulsed direct current sputtering process may be used to improve the deposition rate when forming a high refractive index transparent thin film layer.

Hereinafter, a process of forming a high refractive index transparent thin film through pulsed DC sputtering will be described in detail with reference to the accompanying drawings.

FIG. 3 is a diagram illustrating a process of forming a high refractive index transparent thin film layer through a pulsed DC sputtering process according to an embodiment of the present invention, and FIG. 4 is a diagram illustrating a waveform of a voltage applied to a shield. 5 is a cross-sectional view showing the termination structure (A) of the shield according to an embodiment of the present invention.

First, referring to the sputtering apparatus, as shown in FIG. 3, the TiO _X target 302 is fixed to the backing plate 304 in the chamber 300, and the substrate 306 is disposed below the chamber 300. Is located. Although not shown, the substrate 306 is placed on the substrate holder.

Further, as in the shield (Shieds, 308a and 308b) shown in Figure 3 in a direction perpendicular to the _X TiO target 302 is arranged in the periphery of TiO _X target (302). Here, the shields 308a and 308b have an anode characteristic and at least one recess is formed in a portion thereof, preferably at the end portion thereof, as described below.

Referring to the high refractive index thin film layer formation process using the DC sputtering apparatus having such a structure, after the TiO _X target 302 is mounted and the substrate 306 is placed, the chamber 300 is changed into a vacuum state by the vacuum pump 322. . Here, it is assumed that a metal thin film layer is formed on the substrate 306.

Subsequently, an inert gas (eg argon gas Ar) and oxygen gas O ₂ mixed at a predetermined ratio are injected into the chamber 300. Here, the oxygen gas may be mixed at a rate of 2.5% of the inert gas.

Subsequently, a specific voltage is applied to the TiO _X target 302 acting as a cathode and the shields 308a and 308b acting as an anode, respectively. For example, a specific DC voltage may be applied to the TiO _X target 302, and voltages having a square wave shape as illustrated in FIG. 4 may be applied to the shields 308a and 308b. Here, one of the square waves may be changed while initially switching to a polarity starting with a positive voltage V1 and the remaining square waves may be changed while initially switching to a polarity starting with a negative voltage (-V1). However, the square waves are changed while having opposite polarities.

According to an embodiment of the present invention, the pulsed DC power supply 310 provides the voltages to the TiO _X target 302 and the shields 308a and 308b, and the DC power supply 320 to provide such a square wave voltage. And a distribution controller 322.

The DC power source 320 generates a constant DC voltage, and the distribution controller 322 appropriately distributes the DC voltage to the TiO _X target 302 and the shields 308a and 308b after the DC voltage is deformed as it is or in the form of a pulse. . Here, the frequency of the square waves may be driven as about 20 kHz to 150 kHz since the TiO _X target 302 has a high electrical resistance.

When the voltage is applied in this way, the argon gas Ar is glow discharged to generate Ar ⁺ ions, that is, change into a plasma state. Here, Ar ⁺ ions collide with the TiO _X target 302 as shown in FIG. 3 (not shown, but may activate the collision by using magnetic force), and the collision causes the TiO _X target 302 to sputter. is sputtered. This sputtered TiO _X reacts with O ₂ and is deposited on the substrate 306 as TiO ₂ . For example, TiO ₂ is deposited on the metal thin film layer formed on the substrate to form a second high refractive transparent thin film layer.

In general, in the case of using the simple sputtering method due to the high resistance of the TiO _X target 302, arcing may occur. In the present invention, as described above, the arcing phenomenon may be performed using a pulsed DC sputtering method. Prevent it. Specifically, as shown in FIG. 4, since the square waves are changed while having opposite polarities, the electric field between the shields 308a and 308b is continuously changed, so that the resistance of the TiO _X target 302 is high. Even arcing may not occur. That is, by applying the voltages of the square wave, the high refractive transparent thin film layer can be stably deposited on the substrate or the metal thin film layer.

In the above, the duty ratio of each voltage applied to the shields 308a and 308b was 1, but the duty ratio may vary at different ratios according to the purpose. In addition, a circuit for supplying a voltage to the TiO _X target 302 may exist separately from the pulsed DC power supply 310.

In short, the deposition of the high refractive transparent thin film layer of the present invention uses direct current sputtering to improve the deposition rate, and in particular pulse direct current sputtering is used to prevent arcing due to the high resistance of the TiO _X target 302.

Hereinafter, the structure of the shield 308a or 308b will be described in detail with reference to FIGS. 3 and 5. In FIG. 5, the shield is rotated 180 degrees for easy viewing.

Referring to FIG. 5, one or more recesses 500 are formed in a portion, preferably the termination portion, of the shield 308a or 308b.

In general, the target material is continuously attached to the inner wall of the chamber 300 and the shields 308a and 308b after the film forming process is performed several dozen or more times. As a result, when the film forming process is performed for a long time, the shields 308a and 308b may be changed to non-conductors. In this case, since the cleaning process or the like must be performed, the productivity of the PDP filter is reduced.

Therefore, the stuffing device of the present invention uses the shield 308a or 308b in which the recessed part 500 as shown in FIG. 5 is formed in order to prevent insulatorization of the shields 308a and 308b or to delay the progress of the insulatorization as much as possible. do.

When the recesses 500 are formed in the shields 308a and 308b, the target material may be attached to the outer circumferential surfaces of the shields 308a and 308b but hardly adhere to the inner surfaces corresponding to the recesses 500. Therefore, the insulatorization of the shield 308a or 308b can be delayed as much as possible, and as a result, the productivity of the PDP filter can be improved.

Looking at the shape of the recesses 500 formed in the shields 308a and 308b, the shield 308a or 308b may have a rectangular shape as shown in FIG. 5A, but FIGS. 5B and 5 (FIG. It may have a circular shape as shown in C), it may have a triangular shape as shown in Figure 5 (D).

Referring to FIG. 5B, the spacing between the protrusions 502 due to the recess 500 is the same as in FIG. 5A, but the inner cross-sectional area is wider than in FIG. 5A. Thus, the decontamination of the shield 308a or 308b will proceed more slowly than in FIG. 5 (A).

5C and 5D, the spacing between the protrusions 502 due to the recess 500 is smaller than in FIGS. 5A and 5B. Therefore, the probability of the sputtered target material penetrating into the recess 500 becomes low, so that the nonconducting of the shield 308a or 308b will proceed more slowly than in FIGS. 5 (A) and 5 (B).

Referring to FIG. 5D, the recess 500 may have a multistage shape.

That is, as long as the recess 500 is formed in the shield 308a or 308b to prevent insulatorization of the shield 308a or 308b, the structure, number, etc. of the recess 500 may be variously modified.

In the above, only TiO _X targets are mentioned, but TiO ₂ targets, Nb ₂ O ₅ targets, and the like may also be used in the sputtering apparatus. Of course, the recessed part 500 is formed in the shield 308a or 308b.

In addition, although the recesses 500 are regularly formed in the above, the recesses 500 may be irregularly arranged. For example, some of the intervals of the recesses 500 may be different, some of the lengths of the recesses 500 may be different, and when some of the recesses 500 have a rectangular shape, other recesses may have a circular shape. May have

6 is a cross-sectional view illustrating a PDP filter including four metal thin layers according to an embodiment of the present invention, and FIG. 7 is a diagram illustrating a light transmittance graph of the PDP filter of FIG. 6.

Referring to FIG. 6, the PDP filter of the present embodiment may include a transparent substrate 600 sequentially stacked, a first repeating film 602-1, a second repeating film 602-2, and a third repeating film 602-3. ), A fourth repeating film 602-4, and a second high refractive index transparent thin film layer 604.

The first repeating layer 602-1 is formed on the transparent substrate 600 by sequentially stacking the 1-1 high refractive index thin film layer 610-1, the 1-1 oxide layer 612-1, and the 1-1 metal. It consists of the thin film layer 614-1.

The second repeating film 602-2 is a second high refractive index transparent film layer 610-2 and a second oxide layer 612-2 sequentially stacked on the first metal film layer 614-1. And the first 1-2 metal thin film layer 614-2.

The third repeating film 602-3 is a first high refractive index transparent film layer 610-3 and a first oxide layer 612-3 which are sequentially stacked on the first metal thin film layer 614-2. And the first metal thin film layer 614-3.

The fourth repeating film 602-4 is a first to fourth high refractive index transparent film layer 610-4 and a first to fourth oxide layer 612-4 sequentially stacked on the first to third metal thin film layers 614-3. And a first-4 metal thin film layer 614-4.

In the PDP filter having such a structure, the 1-1 high refractive index thin film layer 610-1 has a thickness of 25 nm, the 1-1 oxide layer 612-1 has a thickness of 5 nm, and 1-1. The metal thin film layer 614-1 is set to have a thickness of 10 nm. In addition, the 1-2 high refractive index thin film layer 610-2 has a thickness of 55 nm, the 1-2 oxide layer 612-2 has a thickness of 5 nm, and the 1-2 metal thin film layer 614-. 2) is set to have a thickness of 10 nm. In addition, the 1-3 high refractive index thin film layer 610-3 has a thickness of 55 nm, the 1-3 oxide layer 612-3 has a thickness of 5 nm, and the 1-3 metal thin film layer 614-. 3) is set to have a thickness of 10 nm. Furthermore, the 1-4th high refractive index thin film layer 610-4 has a thickness of 55 nm, the 1-4 oxide layer 612-4 has a thickness of 5 nm, and the 1-4 metal thin film layer 614-. 4) has a thickness of 10 nm, and the second high refractive transparent thin film layer 604 is set to have a thickness of 25 nm.

As a result of measuring the light transmittance after setting to such a thickness, as shown in FIG. 7, a high light transmittance was obtained in the visible light region, particularly around the wavelength of about 500 nm.

Compared with the prior art, about 80% light transmittance is obtained at 550 nm wavelength in the conventional PDP filter, while about 85% light transmittance is obtained at the 550 nm wavelength in the PDP filter of this embodiment. That is, the light transmittance of the PDP filter of the present embodiment can be higher than the light transmittance of the conventional PDP filter.

Looking back at the above PDP filter structure, the thickness of the 1-2 high refractive index thin film layer 610-2, 1-3 high refractive index transparent film layer 610-3 or 1-4 high refractive index transparent film layer 610-4 ( 55 nm) is confirmed to be greater than the thickness (25 nm) of the 1-1st high refractive transparent thin film layer 601-1 and the thickness (nm) of the 2nd high refractive index transparent thin film layer 604. When the thickness is set in this way, the wavelength range of the low reflection region (reflectance of about 8% or less) becomes wider and the change of the reflection color hardly occurs regardless of the inclination of the PDP panel. That is, the low reflection characteristic and the reflection color characteristic of the PDP filter can be improved.

Although not shown in FIGS. 2 and 6 above, a color correction film, a near infrared shielding film, an antireflection film, and the like may be further formed under the transparent substrate 200 or 600.

8 is a cross-sectional view showing a PDP filter according to another embodiment of the present invention.

Referring to FIG. 8, the PDP filter according to the present embodiment may include a transparent substrate 800, a first repeating film 802-1, a second repeating film 802-2, and a second high refractive transparent thin film layer 804 sequentially stacked. It includes.

The first repeating film 802-1 may include the 1-1 high refractive index transparent film layer 810-1, the 1-1 oxide layer 812-1, the 1-1 metal thin film layer 814-1, and the 2-second. 1 oxide layer 816-1.

The second repeating film 802-2 may include the 1-2 high refractive index thin film layer 810-2, the 1-2 oxide layer 812-2, the 1-2 metal thin film layer 814-2, and the second layer 2-2. 2 oxide layer 816-2.

That is, the second oxide layer 816-1 or 816-2 may be formed between the metal thin film layer 814-1 or 814-2 and the high refractive index transparent thin film layer 810-2 or 804. Here, since the TiO _X (x = 1.5 to 1.99) target is used to form the high refractive index thin film layer 810-1, 810-2, or 804, the second oxide layer 816-1 or 816-2 is formed as much as possible. It can be formed thin.

The embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art having ordinary knowledge of the present invention may make various modifications, changes, and additions within the spirit and scope of the present invention. Should be considered to be within the scope of the following claims.

Claims (8)

A substrate holder holding a substrate;
A back plate supporting a specific target arranged at a position opposite the substrate; And
At least one shield arranged outside the target,
At least one recess is formed in a portion of the shield to prevent insulatorization of the shield. The DC sputtering apparatus of claim 1, wherein the target is a TiO _X (x = 1.5 to 1.99) target, and a DC voltage in the form of a square wave is applied to the shield. The direct current sputtering apparatus according to claim 2, wherein a high refractive index transparent thin film layer made of TiO ₂ is formed on the metal thin film layer of the substrate by using the TiO _X (x = 1.5 to 1.99) target. The direct current sputtering apparatus according to claim 1, wherein the recessed portion has a rectangular shape, an elliptic shape, a triangular shape or a multistage shape. The method of claim 1, wherein the direct current sputtering device,
Further comprising a DC power supply for applying a voltage to the target and the shield, respectively,
The DC power supply unit,
DC power supply for generating a specific DC voltage; And
And a distribution control unit for distributing and distributing the DC power in a pulse form. Supplying a pulsed DC power to at least one shield inside the chamber and supplying a specific DC power to a TiO _X (x = 1.5 to 1.99) target to plasmaate an inert gas in the chamber; And
Sputtering the TiO _X target through the plasmalized inert gas ions to deposit a high refractive index transparent thin film layer formed of TiO ₂ on a substrate,
At least one recess is formed in a portion of the shield to prevent insulatorization. The method of claim 6, wherein the high refractive index transparent thin film layer is deposited on the substrate or on the metal thin film layer formed on the substrate. The method of claim 6, wherein the recess has a rectangular shape, an elliptic shape, a triangular shape, or a multi-stage shape.

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