JP2009102719A - Sputtering system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sputtering system for depositing transparent conductive films on substrates of a large size, where uniformity of a film thickness distribution is secured by suppressing bending of a bar-shaped electrode owing to its self weight and its further bending owing to the stress of transparent conductive films deposited on the electrode in accordance with the increase of the number of the substrates. <P>SOLUTION: In a sputtering system 1 where the transparent conductive film 14 is deposited under a state that a substrate 13 is tilted in a vertical direction to be erected, and a chimney provided with a target 11 and a bar-shaped electrode 12 is arranged in parallel with the substrate 13, the upper edge of the bar-shaped electrode 12 is fixed, the lower part thereof passes through a through-hole 22 with a diameter larger than that of the bar-shaped electrode bored in an electrode holding part 21, and a coil-shaped compression spring 30 sandwiched between the electrode holding part 21 and a spring pressing plate 23 fixed to the lower edge is provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sputtering apparatus for forming a transparent conductive film on a substrate, and in particular, for producing a large-sized liquid crystal display device to be impositioned on a substrate such as a large area glass, a magnetron method. The present invention relates to a sputtering apparatus that forms a transparent conductive film and makes the film thickness distribution more uniform.

  Conventionally, for example, in the production of a liquid crystal panel for color display for a liquid crystal display device, there has been known a sputtering apparatus in which a transparent conductive ITO film (indium tin complex oxide) is applied on a substrate by a magnetron method. From the aspect of imposition production for improving productivity and cost reduction, or from the aspect of the emergence of large liquid crystal display devices in recent years, a magnetron sputtering type sputtering apparatus that forms a film on a large area substrate is used. Has come to be.

  As an example of the sputtering apparatus on the large-area substrate, for example, as shown in the schematic configuration diagram of FIG. 1, a target (11) made of an ITO sintered body installed in a sputtering chamber (10) and a plurality of targets (11). A sputtering apparatus (1) for forming an ITO transparent conductive film (14) on the surface of a substrate (13) running in parallel in front of a chimney (5) having a rod-like electrode (12). As seen from the direction (P), for example, as shown in the schematic cross-sectional view of FIG. 6, the substrate (13) made of large-area glass is tilted upward by about 5 ° with respect to the vertical direction. Sputtering is performed while being transported in a state. The substrate (13) made of large area glass is warped by its own weight when placed horizontally in the state of standing in this manner. Occurs on the board for this It is to prevent the film thickness becomes uneven. Corresponding to this large-area substrate (13), the size of the rod-shaped electrode (12) also increases. In particular, although not shown, in the conventional case where both ends of the rod-shaped electrode are fixed, the heat of the rod-shaped electrode is increased. Due to the elongation and the dead weight, there is a problem that a large amount of bending occurs and the stability of discharge is lacking, and as a result, the film thickness distribution of the deposited ITO becomes non-uniform.

  To solve the above problem, for example, as shown in FIG. 6, the electrode fixing portion of the electrode mounting portion (20) attached to the chimney (not shown) in which the upper end of the rod-like electrode (12) is inclined by about 5 ° There is a sputter apparatus which is fixed to (25) and whose lower end is perforated in the electrode holding part (21) and is free-controlled through a through hole (22) having a diameter larger than that of the rod-shaped electrode (12) ( For example, see Patent Document 1).

The above prior art documents are shown below.
JP 2007-126694 A

  However, in the above prior art, it is impossible to completely prevent the large-sized rod-shaped electrode (12) from being bent due to its own weight, and the surface of the rod-shaped electrode (12) is transparent as the number of film formation increases. When the conductive film is deposited, the rod-like electrode (12) bends due to the stress of the deposited transparent conductive film, and as a result, the film thickness distribution on the substrate (13) becomes non-uniform. .

When the bending of the rod-shaped electrode (12) is verified, for example, as shown in the schematic side view of FIG. 7 (a), the upper end is fixed to the electrode mounting portion (20) of the chimney (5), and the lower portion is the electrode mounting portion. From the wall (K), the rod-shaped electrode (12) which is inserted into a through-hole (not shown) drilled in (21) and is free, together with the chimney (5) having a height (H) of 2360 mm Is tilted so that the lower end of the chimney (5) is in contact with the point where the distance (G) is 1335 mm, and the amount of deflection of the rod-like electrode (12) in the state where the lower end is free in the chimney (5) is measured. As a result, for example, as shown in the graph of FIG. 7 (b), the amount of deflection was about 40 mm at the center of the rod-shaped electrode (12) compared to both ends.

  Further, the amount of the transparent conductive film deposited on the surface of the rod-shaped electrode generated with the increase in the number of processed films is, for example, as shown in the schematic diagrams of FIGS. 8A and 8B. The ITO transparent conductive film 14 is thickly deposited on the target (not shown) side, and thinly deposited on the back side thereof. As shown in the schematic diagram of FIG. 8 (c), the thicker one of the transparent conductive film (14) is caused by the stress of the deposited ITO transparent conductive film (14) as shown in the schematic diagram of FIG. In order to eliminate this bending deflection, the conventional method has a problem that the rod-shaped electrode (12) has to be frequently cleaned and affects productivity as well. It was.

  The present invention solves the problems of the prior art, and the problem is that a plurality of rod-shaped electrodes arranged between the film formation surface of the substrate and the target and in parallel with each other are provided. In the sputtering apparatus which performs film formation processing in a state where the chimney is tilted upright so that the upper end is downward with respect to the vertical direction or the vertical direction, the rod-shaped electrode is bent by its own weight and the substrate An object of the present invention is to provide a sputtering apparatus that ensures the uniformity of the film thickness distribution by suppressing the bending due to the stress of the transparent conductive film deposited on the electrodes as the number of sheets increases.

  In order to achieve the above object in the present invention, first, in the invention of claim 1, a transparent conductive film is formed on the substrate in a state where the substrate is vertically or tilted with respect to the vertical direction, and the target and ground are formed. In a sputtering apparatus in which the plurality of bar electrodes arranged in parallel with the film-forming surface of the substrate, the upper ends of the plurality of grounded bar electrodes are fixed, and the lower part thereof is drilled in the electrode holding portion. The sputtering apparatus is characterized in that a spring is provided so as to pass through a through hole larger than the diameter of the electrode and be sandwiched between the electrode holding portion and a spring pressing plate fixed to the lower end.

  The invention according to claim 2 is the sputtering apparatus according to claim 1, wherein the spring is a coiled compression spring.

  Furthermore, in the invention of claim 3, the film forming method for forming the transparent conductive film on the substrate is a magnetron sputtering method, and the sputtering apparatus of claim 1 or 2 is provided.

  Since this invention is the above structure, there exist the following effects.

  That is, according to the invention according to the above-described claims, the transparent conductive film is formed in a state where the substrate is vertically or tilted with respect to the vertical direction, and the target and the plurality of rod-shaped electrodes that are grounded are formed on the substrate. In the magnetron sputtering type sputtering apparatus arranged parallel to the surface, the upper ends of the plurality of grounded rod-shaped electrodes are fixed, and the lower portion thereof is a through hole larger than the diameter of the rod-shaped electrode drilled in the electrode holding portion The coil-shaped compression spring is provided so as to be sandwiched between the electrode holding portion and the spring pressing plate provided at the lower end thereof, so that the rod-shaped electrode is bent by its own weight and the stress of the transparent conductive film deposited on the electrode. Therefore, it is possible to obtain a sputtering apparatus that ensures the uniformity of the film thickness distribution by suppressing the bending due to.

  That is, by using the force of the coiled compression spring sandwiched between the electrode holding portion and the spring pressing plate to apply a pulling force to the rod-shaped electrode, the deflection due to the weight of the rod-shaped electrode is corrected, and The bending due to the film stress due to the adhesion of the transparent conductive film can also be corrected, and the rod-like electrode can always be kept straight. As a result, the sputtering apparatus can maintain the target, the rod-shaped electrode, and the substrate always in a parallel state and keep the film thickness distribution of the transparent conductive film on the substrate uniform.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a sputtering apparatus of the present invention, which includes a target (11) made of an ITO sintered body and a plurality of rod-shaped electrodes (12) disposed in a sputtering chamber (10). When the substrate (13) travels in the traveling direction (P) and passes in front of the chimney (5), a transparent conductive film (14) is formed on the surface of the substrate (13). Yes.

  FIG. 2 shows an embodiment of the sputtering apparatus of the present invention, in which FIG. 2 (a) is a side view seen from the running direction of FIG. 1, and is a target made of an ITO sintered body. The transparent conductive film (14) is formed with the (11) and the plurality of rod-shaped electrodes (12) and the substrate (13) running in parallel with the vertical electrodes tilted upward with respect to the vertical direction. Is called. FIG. 2B is an enlarged view for explaining the form of the lower end of the rod-like electrode (12), which is a feature of the present invention.

  FIG. 3 is a schematic diagram for explaining the action of the coiled compression spring (30) provided at the lower end of the rod-shaped electrode (12). The coiled compression spring (30) exerts a force to spread. It shows a state where the force is used to pull the rod-shaped electrode (12) downward.

  4A is a front view for explaining the positional relationship between the shape of the chimney (5) constituting the sputtering apparatus of the present invention and the substrate (13), and FIG. 4B is the chimney (5). It is a schematic diagram explaining the role of).

  Furthermore, FIG. 5 is an example of a graph showing the result of measuring the amount of deflection due to the weight of the rod-shaped electrode using the sputtering apparatus of the present invention.

  The present invention is a sputtering apparatus for forming a transparent conductive film on a substrate, and specifically used for manufacturing a liquid crystal display device. For example, as shown in FIG. 2A, a transparent conductive film (14) is formed on a large-area substrate (13) by a magnetron method, and the film thickness distribution is made more uniform. This is a sputtering apparatus for the purpose.

  For example, as shown in the schematic configuration diagram of FIG. 1, the sputtering apparatus of the present invention includes a target (11) and a plurality of rod-shaped electrodes, each of which is a plurality of sets of ITO sintered bodies installed in a sputtering chamber (10). When the substrate (13) runs in parallel in front of the chimney (5) with (12), an ITO transparent conductive film (14) is gradually formed on the surface of the substrate (13). The sputtering apparatus (1).

The sputter apparatus (1) of the present invention is characterized in that, for example, as shown in the side view of FIG. 2 (a) viewed from the substrate running direction of FIG. On the surface of the substrate (13) in a state where the upper end is inclined downward by about 5 °, the transparent conductive film (14
), And a target (11) and a plurality of grounded rod-like electrodes (12) are arranged in parallel to the film-forming surface of the substrate (13), The upper ends of the plurality of grounded rod-shaped electrodes (12) are fixed to the rod-shaped electrode mounting portion (20). As shown in the enlarged view of FIG. 2B, the lower portion of the rod-shaped electrode (12) is the electrode holding portion (21 The coil-shaped compression spring passes through the through-hole (22) larger than the diameter of the rod-shaped electrode drilled in) and is sandwiched between the electrode holding portion (21) and the spring pressing plate (23) provided at the lower end. A sputtering apparatus (1) provided with (30).

  Thus, the upper end of the grounded rod-shaped electrode (12) is fixed to the electrode mounting portion (20), and the lower portion thereof is a through-hole (22 larger than the diameter of the rod-shaped electrode formed in the electrode holding portion (21). ), And the coiled compression spring (30) is provided so as to be sandwiched between the electrode holding portion (21) and the spring pressing plate (23) provided at the lower end, so that the rod-shaped electrode (12) has its own weight. The uniformity of the film thickness distribution can be ensured by suppressing the bending due to the stress and the bending due to the stress of the transparent conductive film deposited on the electrode.

  That is, the action of suppressing the bending by the coiled compression spring (30) is sandwiched between the electrode holding part (21) and the spring pressing plate (23) as shown in the schematic diagram of FIG. The compression spring (30) uses the force to spread, and as shown in the schematic diagram of FIG. 3 (b), the force to which the compression spring (30) tries to spread is the rod electrode (12). By pulling down, the deflection due to the weight of the rod-shaped electrode (12) can be corrected, and the deflection due to the film stress due to the adhesion of the transparent conductive film can also be corrected, so that the rod-shaped electrode can always be kept straight. As a result, for example, as shown in FIG. 2A, the large target (11), the rod-shaped electrode (12), and the large area substrate (13) are always kept in parallel, and as a result, the substrate (13 ) A sputtering apparatus (1) that maintains a uniform film thickness distribution of the transparent conductive film (14) formed thereon.

  The spring (30) is not particularly limited, and may be of a pulling type, a twisting type, a conical compression type, a squeezing type, or the like, but as shown in FIG. 21) and a spring pressing plate (23) provided at the lower end thereof, and is provided so as to insert the rod-like electrode (12) therein, as shown in FIG. From the viewpoint of utilizing the force with which the spring (30) tries to spread, it is preferable to use a coiled compression spring (30).

  Further, for example, as shown in the front view of FIG. 4A and the schematic view of FIG. 4B, the chimney (5) including the plurality of rod-like electrodes (12) is a target made of an ITO sintered body. Because of the rod-like electrode (12) arranged opposite to (11), the spatter discharge phenomenon occurs between the chimney (5) provided with the rod-like electrode (12) and the target (11).

  The chimney (5) is composed of an outer frame (24) and five rod-shaped electrodes (12), and the upper end of the rod-shaped electrode (12) is fixed to the electrode fixing portion (25) of the electrode mounting portion (20). The lower part is passed through a through-hole drilled in the electrode holding part (21), and the lower end thereof is fixed by the spring pressing plate (23), and is sandwiched between the electrode holding part (21) and the spring pressing plate (23). A coiled compression spring (30) is provided, and the lower part of the rod-like electrode (12) is inserted into the compression spring (30).

As shown in FIGS. 2 (a) and 2 (b), the upper end is fixed to the chimney electrode mounting portion (20) and the lower portion is drilled into the electrode holding portion (21). The rod-shaped electrode (12) that is free through the provided through-hole is coiled between the electrode holding portion (21) and the spring pressing plate (22) that fixes the lower end of the rod-shaped electrode (12). A large-sized rod-like electrode (around 2000 mm) using a sputtering apparatus equipped with a compression spring (30)
In order to verify the amount of deflection due to its own weight of 12), the amount of deflection of the rod-like electrode (12) was measured by a method as shown in FIG.

  As a result, for example, as shown in the graph of FIG. 5, the amount of bending was a slight amount of about 10 mm at the center compared to the upper and lower ends. Incidentally, it has been proved that the sputtering apparatus can significantly reduce the amount of bending compared to the amount of bending of about 40 mm in the conventional apparatus not provided with the compression spring shown in the graph.

  Further, in the verification of the suppression of the deflection amount due to the adhesion of the transparent conductive film to the rod-shaped electrode (12) with the increase in the number of processed sheets, although not particularly shown, the deflection amount due to the weight of the rod-shaped electrode (12) is the same. In the case where a compression spring is mounted on the lower part, the amount of bending can be remarkably suppressed. As a result, the rod-shaped electrode (12), which has been frequently used in the past, can be cleaned with a very small interval. It was a sputtering device that contributed to the improvement of productivity.

It is a schematic block diagram which shows one Embodiment of the sputtering device of this invention. 1 shows an embodiment of the sputtering apparatus of the present invention, (a) is a side view seen from the traveling direction of FIG. 1, (b) is an enlarged view for explaining the form of the lower end of the rod-like electrode. is there. It explains the action of the compression spring provided at the lower end of the rod-shaped electrode constituting the sputtering apparatus of the present invention, (a) is a schematic diagram showing a normal mounting state, (b) is a thermal elongation It is a schematic diagram which shows an attachment state when suppressing bending, such as. An example of the chimney constituting the sputtering apparatus of the present invention will be described. (A) is a front view for explaining the positional relationship between the shape and the substrate, and (b) is for explaining the role of the chimney. It is a schematic diagram. It is a graph showing the result of having measured the deflection amount by the dead weight of a rod-shaped electrode using the example of the sputtering device of this invention. It is the side cross-sectional schematic explaining one example of the conventional sputtering device. The measurement of the deflection amount of the rod-shaped electrode which comprises a sputtering device is demonstrated, (a) is a schematic side view of the method of the measurement, (b) is a graph showing the measured result. Explaining the deflection of the rod-shaped electrode as the number of processed sheets increases, (a) is a schematic side view showing a state where a transparent conductive film adheres to the rod-shaped electrode, and (b) is a partially enlarged view thereof. And (c) is a schematic side view showing a bent state of the rod-shaped electrode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sputtering device 5 ... Chimney 10 ... Sputter chamber 11 ... Target 11a ... Backing plate 12 ... Rod electrode 13 ... Substrate 14 ... Transparent conductive film 16 ... Partition valve 20 ... Electrode mounting part 21 ... Electrode holding part 22 ... Through hole 23 ... Spring retainer plate 24 ... Outer frame 25 ... Electrode fixing part 30 ... Spring G ... Distance from wall to contact point with chimney ground H ... Chimney's Height K …… Wall
P ... Direction of board travel

Claims (3)

  A sputtering method in which a transparent conductive film is formed on a substrate in a vertical direction or in a state where the substrate is tilted with respect to the vertical direction, and a target and a plurality of grounded rod-shaped electrodes are arranged in parallel to the film formation surface of the substrate In the apparatus, the upper ends of the plurality of grounded rod-shaped electrodes are fixed, and the lower portions thereof are fixed to the electrode holding portion and the lower ends through a through-hole larger than the diameter of the rod-shaped electrode formed in the electrode holding portion. A sputtering apparatus comprising a spring so as to be sandwiched between spring holding plates.   The sputtering apparatus according to claim 1, wherein the spring is a coiled compression spring.   3. The sputtering apparatus according to claim 1, wherein a film forming method for forming the transparent conductive film on the substrate is based on a magnetron sputtering method.

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