JP2010037594A - Sputtering apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sputtering apparatus which suppresses deposition of particles peeled from a non-erosion area on a substrate at a high level, and used for forming a transparent conductive film. <P>SOLUTION: The sputtering apparatus includes a substrate support, a target support arranged separate from and parallel to the substrate support, and a plurality of magnetic bodies arranged on the target support on the side opposite from the substrate support, and is driven by the power from a power source. The plural magnetic bodies include a first magnetic body located at a center of the target support, and a second magnetic body located on the outer circumferential side of the target support with respect to the first magnetic body. The power of the power source is increasable and reducible. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sputtering apparatus. More specifically, the sputtering apparatus of the present invention relates to a sputtering apparatus that can suitably form a transparent conductive film.

  As an example of a light-emitting element applied to a display device, an organic electroluminescence element having a thin film stack structure mainly composed of an organic compound (hereinafter, sometimes referred to as “organic EL element”) is known.

  Non-Patent Document 1 discloses that holes injected from a transparent electrode made of indium tin oxide (ITO) into a hole injection layer and electrons injected from a low work function electrode into an electron injection layer are recombined in a light emitting layer. An organic laminated high-intensity light-emitting element based on the principle that light emission occurs as a result is disclosed.

  Since the above-described high-luminance light-emitting element has been announced, various studies have been made for practical use of organic EL elements.

  For example, in the field of organic EL displays, active matrix drive type organic EL elements have been actively developed in recent years. In the active matrix driving method, a plurality of organic EL elements are formed on a substrate provided with thin film transistors (TFTs) as switching elements, and a display is configured using these organic EL elements as a light source. In the current active matrix drive type display, the characteristics of the TFT and the organic EL element vary greatly, and various drive circuits are required to correct the dispersion. Further, when the driving circuit is complicated, the number of TFTs required for driving one pixel becomes enormous.

  By the way, an organic EL element applied to a display is generally configured as a bottom emission type element (hereinafter sometimes referred to as a “Bottom-Em type element”) that extracts light from a glass substrate surface. .

  FIG. 6 is a schematic cross-sectional view of a Bottom-Em type element. The Bottom-Em element 100 shown in FIG. 1 includes a glass substrate 102 and a lower electrode 104 made of indium / zinc oxide (IZO), an organic EL layer 106, and an upper electrode 108 made of LiF / Al. When such a Bottom-Em type element 100 is applied to an active matrix drive type display, the area for extracting light L from the lower electrode 102 decreases as the number of TFTs increases.

  Therefore, assuming that it is applied to an active matrix drive type display, a top emission type element (hereinafter referred to as “Top-Em type element”) that takes out light L from the upper electrode side instead of the Bottom-Em type element shown in FIG. ") Is being developed.

  FIG. 7 is a schematic cross-sectional view of a Top-Em type organic EL element. The Top-Em type organic EL element 200 shown in the figure includes a reflective film 204, a lower electrode 206 made of IZO, an organic EL layer 208, and an upper electrode 210 made of IZO on a glass substrate 202 in this order.

  Here, in the Top-Em type organic EL element 200 shown in FIG. 7, it is important that the upper electrode 210 exhibits sufficient light transmittance. For this reason, as the upper electrode 210, a transparent conductive film made of a substance having high visible light transmittance and high electrical conductivity is generally used.

Examples of such transparent conductive films include metal thin films (for example, film thickness of 5 nm or less) such as Au, Ag, Cu, Pt, and Ph, SnO ₂ , TiO ₂ , CdO, In ₂ O ₃ , and ZnO. And oxide semiconductor thin films of these composite materials such as ITO and IZO. A transparent conductive film made of ITO, IZO or the like is formed by sputtering, and is used as an electrode in a wide range of applications such as a television, a transparent heater, and a liquid crystal display element.

  A conventional sputtering apparatus for film formation is a general flat plate magnetron type apparatus in which a magnet is disposed on the back surface of a target. In this type of device, electrons drift while drawing a cycloid curve in a direction in which an electric field and a magnetic field are orthogonal to each other. For this reason, the range of electrons is longer than when no magnet is provided. Therefore, an excellent ionization collision probability, and thus an excellent ion density of the sputtering gas can be achieved, and the sputtering rate can be increased.

  Further, in this sputtering apparatus, magnetized magnets are used for the counter electrodes each having an opposing surface. For this reason, depending on the shape of the magnet, the region where the ionization density of the target is high becomes a ring shape. As a result, since a region having a high ionization density of the target is used in a large amount for sputtering, a region that is highly eroded as compared with other regions, that is, an erosion region is formed.

  On the other hand, in a sputtering apparatus in which such an erosion region is formed, electron drift motion is confined in the ring-shaped region. For this reason, an excellent ionization density cannot be obtained in a region outside the region. Therefore, in a region outside the ring-shaped region, the target is not used much for sputtering, and a region with a low degree of erosion, that is, a non-erosion region is formed.

  In addition, in the non-erosion region, particles sputtered from a neighboring ring region are further deposited. The particles deposited in this way are very easy to peel off, and the peeled particles may be deposited on the substrate. When the particles are deposited on the substrate, the organic EL element may cause a leak or a short circuit, and an excellent yield rate of the element cannot be achieved.

The following technique is disclosed as an improvement measure for such particles generated in the sputtering apparatus.
In Patent Document 1, when a target component is formed on a target object by sputtering using a magnetic field, the magnetic field is applied in the direction of the target surface after film formation on a predetermined number of the target objects. A sputtering film forming method is disclosed that spreads along the surface and cleans the target surface.

  In Patent Document 2, the surface of the processing substrate on which the film is to be formed and the target plate are faced in parallel, an ITO film is formed by magnetron sputtering, and a magnet is attached to the back surface of the target plate that is not on the processing substrate surface side. One or more are arranged, the one or more magnets are swung, and the entire processing substrate surface side of the target plate is used as an erosion region, or the processing substrate surface side of the target plate is set in either the vertical direction or the horizontal direction. In this case, the peripheral portion facing in one direction is left as a non-erosion region, and the other portion is used as an erosion region. An IT in which the processing substrate surface side is a plane along the target plate surface and at least the surface portion of the processing substrate surface side is sintered. Sputtering apparatus is disclosed that is disposed an auxiliary member to be.

  In Patent Document 3, plasma is generated by using a discharge power source and a magnet device in combination, and ions are collided with an oxide target using this plasma to sputter a target material, and transparent conductive material is formed on a relatively large substrate. A single-wafer type magnetron sputtering apparatus is disclosed in which a film is formed, the target has an integral shape, and the discharge power source is a high-frequency power source that supplies a main part of the discharge power.

  Patent Document 4 discloses a magnetron type reactive sputtering apparatus that performs sputtering on a substrate by setting the gas pressure of oxygen as a sputtering gas to a low gas pressure of 15 mTorr or less.

JP 2002-38264 A JP 2007-238978 A JP-A-9-241840 Japanese Patent Laid-Open No. 3-20463 C. W. Tang, S. A. VanSlyke, Appl. Phys. Lett., 51913 (1987), Vol.51, No.12, P.913

  However, in the above Patent Documents 1 to 4, the following problems are inherent.

  In the technique disclosed in Patent Document 1, particles are generated at any time during sputtering. Therefore, by performing cleaning after forming a film on a predetermined number of objects to be processed, the particle level in the non-erosion region is reduced. It cannot be reduced sufficiently.

  In the technique disclosed in Patent Document 2, for example, even if the erosion region is extended to the entire processing substrate surface side of the target plate, particles having a weak adhesion force are always deposited on the outer peripheral portion thereof. For this reason, if the erosion region is not reduced in the process from pre-sputtering to main sputtering, particles separated from the non-erosion region may be deposited on the substrate during main sputtering.

  In the technique disclosed in Patent Document 3, undesired particles are reduced by using the main power source of the sputtering power source as a high-frequency power source and using the swing of the magnet device together, but a magnet swing device is required. Therefore, sputtering cannot be performed at low cost.

  In the technique disclosed in Patent Document 4, the sputtering conditions are changed and cleaning is performed at a low gas pressure. However, there is no disclosure that cleaning is performed by increasing or decreasing the applied power.

  In the techniques disclosed in Patent Documents 1 to 4 shown above, further improvements are required in order to manufacture a favorable organic EL element by suppressing the number of particles that peel from the non-erosion region due to the various circumstances described above. Is desired.

  Therefore, in view of the above problems, an object of the present invention is to provide a sputtering apparatus used for forming a transparent conductive film capable of suppressing, at a high level, particles that are exfoliated from a non-erosion region. It is to provide.

  The present invention includes a substrate support, a target support disposed in parallel with the substrate support, and a plurality of magnetic bodies disposed on the opposite side of the target support from the substrate support. The plurality of magnetic bodies are positioned on the outer peripheral side of the target support with respect to the first magnetic body and the first magnetic body. And a second magnetic body that is capable of increasing or decreasing the power supply power.

  In addition, the present invention provides a substrate support, a pair of target supports that are vertically spaced apart from the substrate support, and each target support is disposed on the opposite side of the other target support. A plurality of magnetic bodies, driven by power supply power, wherein the plurality of magnetic bodies are located at a central portion of the target support, and the target with respect to the first magnetic body. The present invention relates to a sputtering apparatus including a second magnetic body positioned on the outer peripheral side of a support, and the power supply power can be increased or decreased.

  The sputtering apparatus of the present invention can reduce the erosion region during main sputtering as compared with pre-sputtering by increasing or decreasing the power source power. For this reason, according to the sputtering apparatus of the present invention, target particles deposited in the non-erosion region during pre-sputtering are hardly separated by reducing the erosion region during main sputtering, and the deposition of the particles on the substrate is suppressed. Can do. Therefore, when the sputtering apparatus of the present invention is used, a transparent conductive film can be suitably formed on the substrate, and as a result, a high-quality organic EL element can be manufactured.

  Below, the sputtering apparatus of this invention is demonstrated in detail according to drawing. In general, in the formation of the organic EL element, the sputtering process is performed in two processes, a pre-sputter process (when film formation is not performed on the substrate) and a main sputtering process (when film formation is performed on the substrate). For this reason, in the following, the state of the apparatus at the time of these two steps will be illustrated, and each of these states will be described sequentially.

<Embodiment 1: When one backing plate is used (flat plate type)>
FIG. 1 is a schematic side view showing a sputtering apparatus (Embodiment 1) of the present invention, where (a) shows the time of pre-sputtering and (b) shows the time of main sputtering. FIG. 2 is a plan view showing erosion regions of the target T shown in FIG. 1 during pre-sputtering and main sputtering. Specifically, in FIG. 2, the region surrounded by the outermost circle indicates the target existence region up to the center point, and the region E _p surrounded by the second circle from the outside and the fourth circle from the outside is the pre- A relatively large erosion area at the time of sputtering is shown, and an area E _M surrounded by the third circle from the outside and the fourth circle from the outside shows a relatively small erosion area at the time of main sputtering.

  As shown in FIG. 1A, the sputtering apparatus 10 includes a substrate support 12, a backing plate 14 as a target support that is spaced apart from and parallel to the substrate support 12, and a backing plate 14. A magnetic body 16 disposed on the opposite side of the substrate support 12 and a ground shield 18 disposed so as to cover the backing plate 14 from the left and right in the drawing are provided. In this example, the magnetic body 16 includes two cylindrical inner magnets 16a and a cylindrical outer magnet 16b arranged concentrically.

(Substrate support 12)
The substrate support 12 is a component as a jig that supports a substrate (not shown) as a film forming body on the lower side thereof. A material such as stainless steel and copper can be used for the substrate support 12. The substrate support 12 can be formed, for example, by being fixed to a housing (not shown) of the sputtering apparatus by a method such as screwing.

(Backing plate 14)
The backing plate 14 is a component for supporting the target T in FIG. 1A on one side and supporting the magnetic body 16 on the other side. A material such as copper can be used for the backing plate 14.

(Magnetic material 16)
As described above, the magnetic body 16 includes the columnar central magnet 16a and the cylindrical outer peripheral magnet 16b. As the central magnet 16a, a hard magnetic magnet made of SmCo or the like can be used. When the target diameter is 6 inches, the shape can be a cylindrical shape having a diameter of 30 mm and a height of 20 mm. In contrast, a hard magnetic magnet made of SmCo or the like can be used for the outer peripheral magnet 16b, and the shape thereof is a cylinder having an inner diameter of 60 mm, an outer diameter of 75 mm, and a height of 20 mm when the target diameter is 6 inches. Can be used.

(Earth shield 18)
The earth shield 18 is installed in the vicinity of a portion to which high-frequency power is applied, and the distance between the substrate support 12 and the backing plate 14 and the earth shield 18 at the ground potential is set to a distance that is difficult to discharge. It is a component for suppressing discharge. Generally, stainless steel or the like can be used for the earth shield 18.

(Formation of Sputtering Device 10 Using Components 12 to 18)
As shown in FIG. 1A, the backing plate 14 is arranged at a predetermined distance, for example, 400 mm with respect to the substrate support 12.

  Next, as shown in the figure, the magnetic body 16 (central magnet 16a, outer peripheral magnet 16b) is disposed on the opposite side of the backing plate 14 from the substrate support 12. The basic arrangement mode of the magnetic body 16 is as described above. When the magnetic body 16 is set as shown in FIG. 1, the central magnet 16a and the outer peripheral magnet 16b are concentrically arranged, and the inner peripheral end of the outer peripheral magnet 16b extends from the outer peripheral end of the central magnet 16a. For example, the distance is 45 mm. Furthermore, as shown in FIG. 1, the south pole and north pole of the center magnet 16a and the outer periphery magnet 16b are made reverse.

  Furthermore, as shown in the figure, the pair of earth shields 18 are arranged such that the vertical distance from the substrate support 12 is 300 mm and the horizontal distance from the backing plate 14 is 10 mm.

(Operation of sputtering apparatus 10)
The sputtering apparatus 10 thus formed operates as follows. The following example is an example in which the center of the target T is arranged so as to coincide with the center of the central magnet 16a. Further, the apparatus 10 includes a direct current power source (not shown) as a main power source for supplying electric power for discharge (hereinafter sometimes referred to as “DC power source”), and the DC power source for reducing the discharge voltage during sputtering. A high-frequency power supply (not shown) as a sub-power supply superimposed on the power supply (hereinafter also referred to as “RF power supply”) is included.

  The sputtering apparatus shown in FIG. 1 controls the DC power source and the RF power source as appropriate, and relatively increases the power of these power sources during pre-sputtering shown in FIG. 1 (a), while the main power source shown in FIG. 1 (b). At the time of sputtering, the power is relatively reduced to realize each state of both sputtering.

That is, during pre-sputtering, a relatively large power source is applied by a DC power source and an RF power source. Thus, as shown in FIG. 1 (a), high-density plasma generation region P _H in the plasma generation region P is present in a relatively wide range. Therefore, as shown in FIG. 2, the erosion area of the target T (erosion region) E _p is present over a wide range. Further, the magnetic flux Φ in the central region of both the magnets 16a and 16b in FIG. 1A is made parallel to the surface of the target T in FIG. It is preferable in that a current can be passed in a direction orthogonal to each other, whereby plasma is easily generated on the surface of the target T.

  The gas pressure during pre-sputtering is preferably 0.01 to 10 Pa. Discharge becomes possible by setting it to 0.01 Pa or more and 10 Pa or less. These effects are achieved at a more stable level by setting the gas pressure to 0.05 to 0.5 Pa.

From this state, by applying a relatively small power power to the DC power supply and RF power supply, as shown in FIG. 1 (b), high-density plasma generation region P _H 'is relatively narrow range in the plasma generation region P Exists. Therefore, as shown in FIG. 2, the erosion area of the target T (erosion region) E _M are present over a narrow range. Further, the magnetic flux Φ in the central region of both magnets 16a and 16b in FIG. 1B is parallel to the surface of the target T in FIG. It is preferable in that a current can be passed in a direction orthogonal to each other, whereby plasma is easily generated on the surface of the target T.

  The gas pressure during main sputtering is preferably 0.01 to 10 Pa, and more preferably 0.05 to 0.5 Pa, similarly to the gas pressure during pre-sputtering.

  Further, regarding the power source power, the DC power source power (0.5 to 1.5 A) at the time of main sputtering is set to be 1/2 or less the DC power source power at the time of pre-sputtering, and the RF power source at the time of main sputtering. The power (30 to 200 W) is preferably set to ½ times or less the RF power source power during pre-sputtering. By setting such power supply power, the target particles deposited in the non-erosion region at the time of pre-sputtering are less likely to be peeled off at the time of main sputtering based on the reduction of the erosion region at the time of main sputtering with respect to the time of pre-sputtering. Deposition can be suppressed.

  In this example, the DC power source and the RF power source (not shown) are further continuously controlled so that the pre-sputtering time (FIG. 1 (a)) and the main sputtering time (FIG. 1 (b)) are alternately performed. For example, the film formation of a predetermined component of the organic EL element can be continuously performed many times.

  As described above, there are several methods for performing sputtering separately at the time of pre-sputtering and at the time of main sputtering, in addition to the method based on power control of the power source of the present invention. For example, the constituent elements 16a and 16b of the magnetic body 16 shown in FIG. 1 are rearranged during both sputtering to displace the magnetic field (magnetic body rearrangement type), and the concentration of the reactive gas during both sputtering. There is a method (reactive gas change type) to change the pressure.

  However, in the arrangement change type of the magnetic material, the arrangement change is performed by a stepping motor or a cylinder, and these large-scale apparatuses are required, so that sputtering cannot be performed at low cost.

  Further, in the reactive gas change type, since there is no change in the erosion region itself at the time of both sputtering, it is not possible to suitably suppress adhesion of undesired particles from the erosion region and the non-erosion region.

  Accordingly, the sputtering apparatus 10 of the present invention shown in FIG. 1 not only can perform sputtering at a lower cost than the arrangement change type of the magnetic material, but also can suppress adhesion of unwanted particles as compared with the reactive gas change type. It can be said that it is an excellent device.

<Embodiment 2: When two backing plates are used (opposing type)>
FIG. 3 is a schematic side view showing a sputtering apparatus (Embodiment 2) of the present invention, where (a) shows the time of pre-sputtering and (b) shows the time of main sputtering. Since the second embodiment is a design change example of the first embodiment, only differences from the first embodiment will be described below.

  As shown in FIG. 3A, the sputtering apparatus 20 includes a substrate support 12, backing plates 14 and 14 ′ as a pair of target supports that are vertically spaced apart from the substrate support 12, and In each of the backing plates 14 and 14 ', the plurality of magnetic bodies 16 and 16' disposed on the opposite side to the other backing plates 14 'and 14 and the backing plates 14 and 14' And ground shields 18 and 18 'arranged so as to cover from the outside.

Here, in this example, the structures of the magnetic bodies 16 and 16 ′ are both examples using the magnetic body 16 (16a and 16b) of the aspect of the first embodiment shown in FIG. In FIGS. 3A and 3B, symbols P and P ′ are plasma generation regions, and P _H and P _H ′ are high-density plasma generation regions.

  Further, the magnetic flux Φ (Φ ′) in the central region between the magnets 16a (16a ′) and 16b (16b ′) in FIGS. 3A and 3B is parallel to the surface of the target T (T ′). According to Fleming's left-hand rule, a current can be passed in a direction orthogonal to the direction of the magnetic field, which is preferable in that plasma is easily generated on the surface of the target T.

  As in the sputtering apparatus 10 (Embodiment 1) shown in FIG. 1, the sputtering apparatus 20 shown in FIG. 3 is deposited in the non-erosion area at the time of pre-sputtering based on the reduction of the erosion area at the time of main sputtering compared with the time of pre-sputtering. The target particles thus made difficult to peel off during main sputtering, and the deposition of the particles on the substrate can be suppressed.

  Note that the sputtering apparatus 20 shown in FIG. 3 has twice the number of backing plates, magnetic bodies, and earth shields as compared with the sputtering apparatus 10 shown in FIG. 1, and the targets T and T ′ are opposed to each other. I am letting. For this reason, most of the sputtered particles scattered from the opposing targets T and T ′ are deposited not on the non-erosion region but on the opposite targets T ′ and T. Therefore, in the example shown in FIG. 3, deposition of undesired particles on the substrate during main sputtering is suppressed more than in the example shown in FIG. 1 (Embodiment 1). As a result, the effect of reducing the erosion region from pre-sputtering to main sputtering is increased as compared with the first embodiment, and as a result, deposition of the particles on the substrate can be suppressed at a very high level.

  Examples of the present invention will be described below to demonstrate the effects of the present invention.

<Example 1: Relationship between sputtering conditions and yield rate of organic EL elements>
[Formation of organic EL elements]
(Invention Example 1)
An organic EL element was formed using the sputtering apparatus 10 shown in FIG.

  First, CrB was formed as a reflective electrode on a glass substrate. The reflective electrode was formed by performing DC sputtering using Ar as the sputtering gas at room temperature. Specifically, pre-sputtering was performed for 30 minutes with a DC power supply power of 300 W. Next, main sputtering was performed under the same conditions as in pre-sputtering with DC power. That is, the reflective electrode material CrB is not a highly reactive compound and is not an oxide such as a transparent conductive film. For this reason, the erosion area | region at the time of main sputtering was not reduced compared with the erosion area | region at the time of pre-sputtering. Finally, patterning, drying at 150 ° C., and UV treatment at room temperature and 150 ° C. were sequentially performed to obtain a reflective electrode having a thickness of 100 nm made of CrB.

Next, the laminated body in which the reflective electrode was formed on the glass substrate was moved to the vapor deposition apparatus, and the organic EL layer was formed with the internal pressure of the vacuum chamber set to 1 × 10 ⁻⁵ Pa.

  As the organic EL layer, an electron injection layer, an electron transport layer, a light emitting layer, a hole transport layer, and a hole injection layer were sequentially formed. In the electron injection layer, a mixture of aluminum chelate (Alq3) and 50 mol% Li was formed with a film thickness of 10 nm. In the electron transport layer, aluminum chelate (Alq3) was formed with a thickness of 10 nm. In the light-emitting layer, 4,4′-bis (2,2′-diphenylvinyl) biphenyl (DPVBi) was formed to a thickness of 35 nm. In the hole transport layer, t-butyl peroxybenzoate (TBPB) was formed with a film thickness of 10 nm. In the hole injection layer, copper phthalocyanine (CuPc) was formed with a film thickness of 75 nm.

  Further, an upper electrode made of indium / zinc oxide (IZO) was formed on the organic EL layer using the sputtering apparatus 10 shown in FIG. 1 and a metal mask.

  First, Ar was used as the sputtering gas, the current of the DC power source was 1.8 A, the power source power of the RF power source was 300 W, and pre-sputtering was performed for 90 minutes.

Next, Ar containing 1% O ₂ was used as the sputtering gas, the current of the DC power source was 0.6 A, the power source power of the RF power source was 30 W, and an IZO film with a thickness of 200 nm was obtained.

  Finally, a passivation layer having a thickness of 3 μm was formed on the upper electrode by a CVD method.

  The organic EL element obtained as described above was subjected to UV sealing. The UV sealing was performed by moving the organic EL element to a glove box (both oxygen concentration and water concentration were several ppm or less) and applying a getter material inside the sealing without exposing the organic EL element to the atmosphere.

(Invention Example 2)
The organic EL element was formed using the sputtering apparatus 20 shown in FIG. That is, a reflective electrode, an organic EL layer, and an upper electrode are formed on a glass substrate in the same manner as in Example 1 of the present invention. Finally, UV sealing is applied to the formed organic EL element in the same manner as in Example 1 of the present invention. went.

(Comparative Example 1)
Although the sputtering apparatus 20 shown in FIG. 3 was used, when forming the upper electrode, the power of the DC power source (1.8 A) and the power of the RF power source (300 W) were not changed during pre-sputtering and main sputtering, That is, the organic EL element was formed without reducing the erosion region. For other matters, an organic EL element was formed in the same manner as in Example 2 of the present invention.

[Evaluation of non-defective rate of organic EL elements]
The organic EL elements of Examples 1 and 2 of the present invention and Comparative Example 1 obtained as described above were driven as follows, and the non-defective rate based on leakage / short circuit was investigated. The organic EL element was driven by a constant current.

  Next, the subpixels that were not turned on and the subpixels that became dark due to deterioration were each photographed with a high-precision camera, and the total number of these subpixels (number of defective subpixels) was calculated. Finally, the non-defective rate is the ratio of the difference between the total number of subpixels and the number of defective subpixels to the total number of red, green, and blue subpixels (total number of subpixels) when the organic EL element is applied to the display. Calculated as The results are shown in Table 1.

  As shown in Table 1, since both the inventive examples 1 and 2 within the scope of the present invention have a reduced erosion area during main sputtering compared to pre-sputtering, an excellent yield rate can be achieved. I understand. Further, in particular, in contrast to the flat-plate-type invention example 1, the opposed-type invention example 2 particularly has the opposite targets T ′, T where most of the sputtered particles scattered from the opposed targets T, T ′ are opposite to each other. Therefore, deposition of undesired particles on the substrate during main sputtering can be suppressed. Therefore, in Example 2 of the present invention, it can be seen that the effect of changing the erosion region during pre-sputtering and during main sputtering is large, and as a result, a very good yield rate is obtained.

  On the other hand, it can be seen that Comparative Example 1, which is outside the scope of the present invention, does not reduce the erosion area at the time of main sputtering compared to that at the time of pre-sputtering, and therefore does not realize an excellent yield rate. This is because the erosion region was not reduced, and a large amount of particularly large particles existed in the upper electrode of the top emission type organic EL element, and as a result, the particles became a passivation layer on the upper electrode. This is because a defective sub-pixel was formed by breaking through.

<Example 2: Relationship between change of erosion region and undesired number of particles>
[Formation of organic EL elements]
(Comparative Example 2)
The organic EL element was formed using the sputtering apparatus 20 shown in FIG. That is, first, a reflective electrode and an organic EL layer were formed on a glass substrate in the same manner as in Example 2 of the present invention.

  Next, an upper electrode made of indium / zinc oxide (IZO) was formed on the organic EL layer using the sputtering apparatus 20 shown in FIG. 3 and a metal mask.

  First, Ar was used as the sputtering gas, the current of the DC power source was 1.22 A, the power source power of the RF power source was 150 W, and pre-sputtering was performed for 30 minutes.

Next, using Ar containing 1% O ₂ as a sputtering gas, the current of the DC power source was 1.22 A, the power source power of the RF power source was 150 W, and main sputtering was performed to obtain an IZO film with a thickness of 100 nm. . That is, in this example, the erosion area at the time of main sputtering was not reduced compared to the erosion area at the time of pre-sputtering.

  Finally, UV sealing was performed on the formed organic EL element in the same manner as in Invention Example 2.

(Invention Example 3)
The DC power source current during pre-sputtering is 1.22 A, the RF power source power is 150 W, the DC power source current during main sputtering is 0.61 A, and the RF power source power is 30 W, that is, the erosion region. Was reduced to form an organic EL element. For other matters, an organic EL element was formed as in Comparative Example 2.

(Comparative Example 3)
The DC power source current during pre-sputtering is 0.61 A, the RF power source power is 30 W, the DC power source current during main sputtering is 0.61 A, and the RF power source power is 30 W, that is, the erosion region. The organic EL element was formed without reducing the size. For other matters, an organic EL element was formed as in Comparative Example 2.

[Evaluation of Undesired Particle Number of Organic EL Device]
Regarding the organic EL elements of Comparative Examples 2 and 3 and Invention Example 3 obtained as described above, the number of target particles attached to the dummy glass substrate was investigated. The result is shown in FIG. The symbols S, M, L, and O shown in FIG. 4 indicate particles having an average particle diameter of more than 2 μm, more than 4 μm, more than 6 μm, and more than 20 μm, respectively, and the numerical values in the bar graph indicate these particle diameters. It is a numerical value indicating how many particles have in each example.

  As shown in FIG. 4, Example 3 of the present invention, which is within the scope of the present invention, has a reduced erosion area during main sputtering as compared with pre-sputtering, resulting in a smaller number of particles, resulting in a superior product. It can be seen that the rate is realized. On the other hand, since Comparative Examples 2 and 3 which are outside the scope of the present invention do not reduce the erosion area during main sputtering compared to during pre-sputtering, the number of particles is large, resulting in excellent products. It can be seen that the rate has not been realized. Note that, among the particles belonging to each of the classifications S, M, L, and O, in particular, when there are many particles belonging to the classifications O and L, there is a high possibility that they will be defective. 3 is estimated to be a good product rate.

<Example 3: Relationship between pre-sputtering time and undesired number of particles>
[Formation of organic EL elements]
(Reference Example 1)
The organic EL element was formed using the sputtering apparatus 20 shown in FIG. That is, first, a reflective electrode and an organic EL layer were formed on a glass substrate in the same manner as in Example 2 of the present invention.

  Next, an upper electrode made of indium / zinc oxide (IZO) was formed on the organic EL layer using the sputtering apparatus 20 shown in FIG. 3 and a metal mask.

  First, Ar was used as the sputtering gas, the current of the DC power source was 1.8 A, the power source power of the RF power source was 300 W, and pre-sputtering was performed for 30 minutes.

Next, using Ar containing 1% O ₂ as a sputtering gas, the current of the DC power source was 0.6 A, the power source power of the RF power source was 30 W, and main sputtering was performed to obtain IZO having a film thickness of 200 nm. .

  Finally, UV sealing was performed on the formed organic EL element in the same manner as in Invention Example 2.

(Reference Example 2)
An organic EL element was formed in the same manner as in Reference Example 1 except that the pre-sputtering time was 60 minutes.

(Reference Example 3)
An organic EL element was formed in the same manner as in Reference Example 1 except that the pre-sputtering time was 90 minutes.

[Evaluation of Undesired Particle Number of Organic EL Device]
Regarding the organic EL elements of Reference Examples 1 to 3 obtained as described above, the number of target particles attached to the dummy glass substrate was investigated. The result is shown in FIG.

  As shown in FIG. 5, it can be seen that the pre-sputtering time is 60 minutes or more, and more favorable results are obtained with respect to the number of undesired particles.

  Since the sputtering apparatus of the present invention has a DC power source and an RF power source that can be controlled in a predetermined manner, the erosion region at the time of main sputtering can be reduced as compared with the time of pre-sputtering. For this reason, according to the sputtering apparatus, target particles deposited in the non-erosion region during pre-sputtering can be made difficult to peel off during main sputtering, and deposition of the particles on the substrate can be suppressed. It is possible to suitably form the conductive film. Therefore, the present invention is promising in that it can be applied in the field of organic EL displays, where it is desired to manufacture higher-quality organic EL elements in the future.

It is a typical side view which shows an example of the sputtering apparatus (flat plate type) of this invention using one backing plate, (a) shows the time of pre-sputtering, (b) shows the time of main sputtering. It is a top view which shows each erosion area | region at the time of the pre-sputtering and the main sputtering of the target T shown in FIG. It is a typical side view which shows an example of the sputtering apparatus (opposite type) of this invention using a pair of backing plates, (a) shows the time of pre-sputtering, (b) shows the time of main sputtering. It is a graph which shows the relationship between the number of particle | grains and the change of an erosion area | region. It is a graph which shows the relationship between a particle number and pre-sputtering time. It is a typical sectional view of a Bottom-Em type element. It is a typical sectional view of a Top-Em type organic EL device.

Explanation of symbols

10 sputtering apparatus 12 the substrate support 14 the backing plate 16 magnetic 16a central magnet 16b outer peripheral magnet 18 earth shield P plasma generation region P _H, P _H 'high-density plasma generation area T target Φ magnetic flux

Claims (2)

  A substrate support; a target support disposed parallel to and spaced from the substrate support; and a plurality of magnetic bodies disposed on the opposite side of the target support from the substrate support. In the sputtering apparatus driven by the plurality of magnetic bodies, the plurality of magnetic bodies are positioned on the outer peripheral side of the target support body with respect to the first magnetic body and the first magnetic body. A sputtering apparatus comprising: a second magnetic body, wherein the power supply power can be increased or decreased.   A substrate support, a pair of target supports disposed vertically apart from the substrate support, and a plurality of magnetic bodies disposed on the opposite side of the other target support in each of the target supports; The plurality of magnetic bodies includes a first magnetic body located at a center portion of the target support, and a second magnetic body located on an outer peripheral side of the target support with respect to the first magnetic body. A sputtering apparatus including a body and driven by power supply power, wherein the power supply power can be increased or decreased.

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