JP2010116597A - Ion-plating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ion-plating apparatus capable of obtaining the consistent film deposition rate, and obtaining the stable discharge without executing any preliminary work for forming an electric path. <P>SOLUTION: The ion-plating apparatus comprises a vacuum chamber 3, a plasma gun 4 for generating plasma beam P inside the vacuum chamber 3, a hearth 5 in which the plasma beam P is applied inside the vacuum chamber 3, and a tablet supporting bar 25 for supporting a tablet 21 for film deposition so as to be exposed inside the vacuum chamber 3 from the hearth 5. The tablet supporting bar 25 is conductive, and the hearth 5 is insulated from the tablet 21 inside the vacuum chamber, and electrically connected to the tablet supporting bar 25 via a hearth resistor 17 outside the vacuum chamber 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ion plating apparatus, and more particularly to a push-up type ion plating apparatus.

  Conventionally, a push-up type ion plating apparatus is known as an ion plating apparatus using a plasma beam (see, for example, Patent Document 1). In this ion plating apparatus, a tablet as an evaporation source is accommodated in a through-hole formed in the hearth, and the tablet is continuously drawn out into the chamber by being pushed up from below by an insulating push-up bar. . Then, the plasma beam generated in the chamber is guided toward the hearth by a steering coil or the like, and the upper surface of the tablet fed into the chamber is irradiated so that the gas generated by the irradiation passes through the plasma beam and is ionized. The film is deposited on the surface of the substrate.

At this time, the negative charge that moves the tablet by the irradiation of the plasma beam is configured to return to the power source through the conductive hearth because the push-up bar is insulative. In such a configuration, in order to suppress abnormal discharge between the tablet and the hearth in the chamber, prior work is performed to form an electrical path between the tablet and the hearth before the ion plating apparatus is operated. Has been. In this preliminary work, the tablet is filled with powdered tablets in the gap between the tablet and the hearth. An electrical path is formed.
JP 2002-30422 A

  However, in the ion plating apparatus described above, an electrical path is formed by prior work to suppress abnormal discharge, but the consumption rate of the tablet cannot be made constant and the film formation rate can be stabilized. There was a problem that I could not. In other words, the plasma beam is applied to the hearth and the tablet, but the amount of irradiation on the tablet changes if the surface condition of the hearth or the vacuum atmosphere in the chamber is different. It was not possible to stabilize the film formation rate.

  In addition, the amount of current that flows through the tablet can be controlled by adjusting the total current to vary the intensity of the plasma beam. However, it depends on the ionization performance that depends on the intensity of the plasma beam and the amount of current that flows through the tablet. Since the tablet consumption rate cannot be controlled independently, the film formation rate could not be stabilized.

  Moreover, in the above ion plating apparatus, since the electrical path is formed by the preliminary work before operation, there is a problem that a stable electrical path cannot be formed in continuous film formation at the time of mass production. there were. For this reason, in continuous film formation at the time of mass production, since there is no stable electrical path between the tablet and the hearth, abnormal discharge is likely to occur, and various characteristics of the formed film are deteriorated. there were.

  The present invention has been made in view of the above points, and can provide a stable film formation rate, and an ion plate that can obtain a stable discharge without performing prior work for forming an electrical path. It is an object of the present invention to provide a lighting device.

  The ion plating apparatus of the present invention functions as a chamber, a cathode, a plasma beam generation source that generates a plasma beam in the chamber, a hearth that functions as an anode and is irradiated with the plasma beam in the chamber, An evaporation source support part that supports an evaporation source for film formation that is disposed in proximity to the hearth so as to be exposed in the chamber, the evaporation source support part is electrically conductive, and the hearth is connected to the chamber. It is insulated from the evaporation source inside, and is electrically connected to the evaporation source support part via a resistor outside the chamber.

According to this configuration, since the hearth as the anode is insulated from the evaporation source, current flows separately to the hearth and the evaporation source, and abnormal discharge in the hearth and the evaporation source can be suppressed in the chamber. The amount of current flowing through the evaporation source can be made constant. In addition, since the hearth is electrically connected to the evaporation source support through a resistor outside the chamber, the intensity of the plasma beam and the amount of current flowing to the evaporation source are independently adjusted according to the resistance value of the resistor. Thus, the ionization performance and the consumption rate of the evaporation source can be appropriately controlled. In this way, abnormal discharge can be prevented, and the intensity of the plasma beam and the amount of current flowing to the evaporation source can be controlled, so that a stable film formation rate can be obtained with a constant consumption rate of the evaporation source.
In addition, since current can be separately supplied to the hearth and the evaporation source in the chamber, abnormal discharge is performed without forming an electrical path between the hearth and the evaporation source in the chamber by performing pre-operation before operation. Therefore, continuous film formation at the time of mass production becomes possible.

  According to the present invention, in the ion plating apparatus, the resistor is a variable resistor, a current detection unit that detects a current flowing through the evaporation source, and a resistance value of the resistor based on a detection result of the current detection unit And a resistance value control unit for controlling.

  According to this configuration, since the resistance value of the resistor is dynamically controlled based on the current actually flowing through the evaporation source, the amount of current flowing through the evaporation source can be controlled with high accuracy. In addition, since the current detection unit allows the operator to grasp the amount of current actually flowing to the evaporation source, a more stable film formation rate can be obtained.

  According to the present invention, in the ion plating apparatus, the current detection unit detects a current flowing through the evaporation source during film formation, and the resistance value control unit controls a resistance value of the resistor during film formation. It is characterized by doing.

  According to this configuration, since the resistance value of the resistor is controlled during film formation, and the amount of current flowing through the evaporation source is controlled with high accuracy, a more stable film formation rate can be obtained.

  According to the present invention, in the ion plating apparatus, a flexible conductive sheet is provided on a support surface of the evaporation source support portion that supports the evaporation source.

  According to this configuration, since the evaporation source is supported by the evaporation source support through the flexible conductive sheet, the evaporation source and the evaporation source are supported via the flexible conductive sheet even if the surface of the evaporation source is rough. The contact area with the part increases and the contact resistance decreases. Thereby, the potential difference between the evaporation source and the evaporation source support portion is reduced, and abnormal discharge can be suppressed.

  In the ion plating apparatus according to the present invention, the evaporation source support portion includes a holding portion that elastically holds the evaporation source.

  According to this configuration, since the evaporation source is elastically held by the holding portion, the contact between the evaporation source support portion and the evaporation source is improved and the contact resistance is reduced. Thereby, the potential difference between the evaporation source and the evaporation source support portion is reduced, and abnormal discharge can be suppressed.

  According to the present invention, in the ion plating apparatus, the hearth is provided on a side surface of the chamber.

  According to this configuration, since the hearth provided on the side surface of the chamber is elastically sandwiched without dropping off the evaporation source, it is possible to form a film on the substrate surface with the substrate standing. As a result, the substrate does not bend due to its own weight as in the state where the substrate is horizontal, so that it is possible to form a film on a large substrate having a large area by providing a plurality of hearts on the side surface of the chamber.

  According to the present invention, a stable film formation rate can be obtained, and a stable discharge can be obtained without prior work for forming an electrical path.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the ion plating apparatus according to the present embodiment suppresses abnormal discharge in the vacuum chamber by insulating the hearth as the anode and the tablet as the evaporation source in the vacuum chamber, and also removes the hearth and the tablet outside the chamber. Are electrically connected via a resistor to control the amount of current flowing through the tablet, so that the consumption rate of the tablet can be made constant and a stable film formation rate can be obtained.

  The overall configuration of the ion plating apparatus will be described with reference to FIG. FIG. 1 is a schematic diagram of an ion plating apparatus according to a first embodiment of the present invention.

  As shown in FIG. 1, an ion plating apparatus 1 according to the present embodiment includes an airtight vacuum chamber 3, and a side wall 3a of the vacuum chamber 3 serves as a plasma beam generation source that functions as a cathode. A plasma gun 4 is provided, and a hearth 5 functioning as an anode is provided on the bottom wall 3 b of the vacuum chamber 3. A transfer device 6 for transferring the workpiece W to be deposited is provided on the upper wall 3c of the vacuum chamber 3, and an oxygen gas is provided on the side wall 3d facing the side wall 3a provided with the plasma gun 4 of the vacuum chamber 3. In addition, a gas inlet 3e for introducing a carrier gas such as argon gas is formed.

  The plasma gun 4 irradiates the hearth 5 with the plasma beam P. The plasma gun body 11 that generates the plasma beam P and the plasma gun body 11 on the vacuum chamber 3 side are coaxial with the plasma gun body 11. The first intermediate electrode 12 and the second intermediate electrode 13 are arranged. The plasma gun main body 11 is connected to the negative terminal of the DC power supply 16 via the conductor plate 14, and generates a plasma beam P by generating a discharge between the conductor plate 14 and the hearth 5. The first intermediate electrode 12 and the second intermediate electrode 13 each have a built-in permanent magnet, and the plasma beam P generated by the plasma gun is converged by the permanent magnet.

  Further, a portion of the plasma gun 4 that protrudes outside the vacuum chamber 3 is provided with a first coil 15 so as to surround the periphery, and the first coil 15 causes the first intermediate electrode 12 and the second coil 15 to be surrounded by the first coil 15. The plasma beam P drawn to the intermediate electrode 13 is guided into the vacuum chamber 3.

  The hearth 5 attracts the plasma beam P emitted from the plasma gun 4 downward, is formed of a conductive material, and is connected to the plus terminal of the DC power source 16 via the hearth resistor 17. The hearth 5 is formed with a through hole 5a at a central portion where the plasma beam P is incident, and the through hole 5a is filled with a columnar tablet 21. An insulating pipe 23 is provided around the through-hole 5 a, and the hearth 5 and the tablet 21 are insulated inside the vacuum chamber 3. In addition, the inside of the vacuum chamber 3 in this Embodiment includes the part by which the vacuum atmosphere is maintained by packing etc. which are not shown in figure like the opposing space etc. of the insulation pipe 23 and the tablet 21. FIG.

  A tablet support bar 25 that supports the tablet 21 from below is provided on the same axis of the through-hole 5 a so as to be movable up and down. The tablet 21 is pushed up by the tablet support bar 25, and the tablet 21 is moved against the hearth 5. Supplied. The tablet support bar 25 is formed of a conductive material, is electrically connected to the tablet 21 on the support surface that supports the tablet 21, and is connected to the plus terminal of the DC power supply 16 outside the vacuum chamber 3.

  Further, as shown in FIG. 2, the tablet support bar 25 includes a bar-shaped part 25a extending in the vertical direction, a support part 25b for supporting the tablet 21 at the upper part of the bar-shaped part 25a, and the tablet 21 being elastic at the support part 25b. And a clamping portion 25c for clamping. The rod-like portion 25 a is connected to a drive mechanism (not shown) and is moved upward in accordance with the consumption speed of the tablet 21.

  The support portion 25b has a support surface 25d that supports the tablet 21 from below, and the conductive sheet 27 is placed on the support surface 25d. The conductive sheet 27 is formed into a sheet shape having flexibility and conductivity using graphite or the like, and fills the roughness on the lower surface of the tablet 21 to increase the contact area between the tablet 21 and the tablet support rod 25. .

  The sandwiching portion 25c has a spring property, sandwiches the circumferential surface of the columnar tablet 21 from the left and right, and improves the contact between the tablet 21 and the tablet support bar 25. As described above, the contact area between the tablet 21 and the tablet support bar 25 is increased by the conductive sheet 27, and the contact between the tablet 21 and the tablet support bar 25 is improved by the sandwiching portion 25c. The contact resistance between them and the potential difference decreases, and abnormal discharge is suppressed.

  Returning to FIG. 1, a portion of the hearth 5 that protrudes outside the vacuum chamber 3 is provided with a second coil 29 so as to surround the periphery, and plasma incident on the hearth 5 by the second coil 29. The direction of the beam P is corrected.

  The tablet 21 is an evaporation source for film formation, and is sintered and formed into a cylindrical shape with powders of zinc oxide and gallium oxide. When the upper surface of the tablet 21 is irradiated with the plasma beam P, it is heated and sublimated by the plasma beam, and a ZnO film is formed on the surface of the workpiece W positioned above the tablet 21.

  Further, the tablet 21 used in the present embodiment is a long-sized tablet 21 of 60 [mm] or more, and is different from a state in which small-sized tablets of about 20 [mm] are stacked in a vertical row. There are fewer seams. Thereby, the abnormal discharge which arises in the joint between tablets is suppressed. In addition, if the tablet is consumed and only fine debris remains, the debris scatters inside the vacuum chamber 3 and causes contamination. However, since there are few joints between the tablets, It is also possible to suppress contamination.

  The transfer device 6 supports the workpiece W above the hearth 5 in the vacuum chamber 3.

  The DC power supply 16 is a variable DC power supply. The plasma gun 4 is connected to the minus terminal, and the tablet 21 is connected to the plus terminal via the hearth resistor 17 and the hearth 5 and the tablet support rod 25. Then, when the DC power source 16 applies a DC voltage between the hearth 5 and the plasma gun 4, a plasma beam P is generated inside the vacuum chamber 3, and a film forming process is performed on the workpiece W. Note that the intensity of the plasma beam P depends on the applied voltage of the DC power supply 16.

  Specifically, when a DC voltage is applied between the hearth 5 and the plasma gun 4 by the DC power supply 16, a plasma beam P is generated. The plasma beam P is guided to a magnetic field formed by the first coil 15 and the second coil 29 and is applied to the hearth 5. The upper surface of the tablet 21 supplied to the hearth 5 by the tablet support rod 25 is heated and sublimated by the irradiation of the plasma beam P. The gas in the tablet 21 is ionized while passing through the plasma beam P and adheres to the surface of the workpiece W to form a film.

  Next, with reference to FIG. 3, the movement path of the negative charge at the time of plasma beam irradiation will be described. FIG. 3 is an explanatory diagram of the movement path of the negative charge when the plasma beam is irradiated.

  As shown in FIG. 3, when the hearth 5 and the tablet 21 are irradiated with the plasma beam P, negative charges move through the hearth 5 and the tablet 21 according to the intensity of the plasma beam P. At this time, since the insulating pipe 23 is provided on the inner peripheral surface of the through hole 5 a of the hearth 5, the negative charges moving the hearth 5 and the tablet 21 do not transfer to each other inside the vacuum chamber 3. The negative charge moving through the hearth 5 returns to the DC power supply 16 via the hearth resistor 17, and the negative charge moving through the tablet 21 returns to the DC power supply 16 via the tablet support rod 25.

  Thus, since the hearth 5 and the tablet 21 are insulated by the insulating pipe 23 inside the vacuum chamber 3, abnormal discharge is suppressed. Moreover, since current flows separately through the hearth 5 and the tablet 21, the amount of current flowing through the tablet 21 is constant. Further, since the hearth resistor 17 is provided between the hearth 5 and the DC power source 16, the amount of current flowing through the hearth 5 and the amount of current flowing through the tablet 21 are adjusted.

  In this case, even if the applied voltage between the hearth 5 and the plasma gun 4 is adjusted and the intensity of the plasma beam P is varied, the tablet can be replaced by replacing the hearth resistor 17 with an appropriate resistance value. The amount of current flowing through 21 can be controlled. For example, when it is desired to increase the intensity of the plasma beam P to improve the ionization performance and to suppress the consumption rate of the tablet 21, the resistance value of the hearth resistor 17 is reduced to allow excess current to escape to the hearth 5. To.

  As described above, according to the ion plating apparatus 1 according to the present embodiment, since the hearth 5 and the tablet 21 are insulated inside the vacuum chamber 3, current flows separately through the hearth 5 and the tablet 21. In the vacuum chamber 3, abnormal discharge in the hearth 5 and the tablet 21 can be suppressed, and the amount of current flowing through the tablet 21 can be made constant.

  In addition, since the hearth 5 is electrically connected to the tablet support rod 25 via the hearth resistor 17 outside the vacuum chamber 3, the intensity of the plasma beam P and the tablet 21 are changed according to the resistance value of the hearth resistor 17. The flowing current amount can be adjusted independently, and the ionization performance and the consumption rate of the evaporation source can be appropriately controlled. In this manner, abnormal discharge can be prevented and the intensity of the plasma beam P and the amount of current flowing through the tablet 21 can be controlled. Therefore, a stable film formation rate can be obtained with the consumption rate of the tablet 21 constant.

  In addition, since current can be separately supplied to the hearth 5 and the tablet 21 inside the vacuum chamber 3, electrical work is performed between the hearth 5 and the tablet 21 inside the vacuum chamber 3 by performing a pre-operation before operation. Abnormal discharge can be suppressed without forming a pass, and continuous film formation at the time of mass production becomes possible.

  Next, a second embodiment of the present invention will be described. The ion plating apparatus according to the second embodiment of the present invention is different from the ion plating apparatus according to the first embodiment described above only in that the hearth resistance can be dynamically controlled. Therefore, only the differences will be particularly described. FIG. 4 is a schematic diagram of an ion plating apparatus according to the second embodiment of the present invention.

  As shown in FIG. 4, the ion plating apparatus 31 of the second embodiment of the present invention is different from the ion plating apparatus 1 of the first embodiment of the present invention only in circuit configuration. The hearth 35 is connected to the plus terminal of the DC power supply 46 through the hearth resistor 47, and the tablet support bar 55 is connected to the plus terminal of the DC power supply 46 through the ammeter 48. The hearth resistor 47 is a variable resistor, and the amount of current flowing through the hearth 35 and the tablet 51 is adjusted by changing the resistance value.

  The ammeter 48 and the hearth resistor 47 are each connected to a resistance value control unit 49, and the resistance value control unit 49 dynamically controls the resistance value of the hearth resistor 47 according to the detected value of the ammeter 48. is doing. As described above, since the resistance value of the hearth resistor 47 is controlled while monitoring the amount of current flowing through the tablet 51, a constant current can flow through the tablet 51, and the surface state of the hearth 35 and the inside of the vacuum chamber 33 can be controlled. Even if the vacuum atmosphere is different, the consumption rate of the tablet 51 can be kept constant.

  As described above, according to the ion plating apparatus 31 according to the present embodiment, the current actually flowing through the tablet 51 is detected by the ammeter 48, and the resistance control unit 49 detects the hearth resistance 47 based on the detected value. Since the resistance value is dynamically controlled, the amount of current flowing through the tablet 51 can be controlled with high accuracy. Further, the ammeter 48 can make the operator know the amount of current that actually flows through the tablet 51. Therefore, a more stable film formation rate can be obtained.

  In each of the above-described embodiments, the hearths 5 and 35 are provided on the bottom walls 3b and 33b of the vacuum chambers 3 and 33, and the film is formed on the surface of the work W from below, but as shown in FIG. In addition, a plurality of hearths 65 may be provided on the side wall 63d of the vacuum chamber 63 so as to form a film on the surface of the workpiece W from the side. With this configuration, it is possible to form a film on the surface of the work W in a state where the work W is upright, and since the work W is not bent due to its own weight as in a horizontal state, the film is formed on a large-sized work having a large area. It becomes possible.

  Moreover, in each above-mentioned embodiment, although it comprised so that the surrounding surface of the tablet 21 might be pinched | interposed from right and left by the clamping part 25c of the tablet support rod 25, it is not limited to this structure, The tablet 21 and tablet support Any configuration is possible as long as the contact with the rod 25 is improved. For example, the tablet support rod 25 may be provided with a bottomed cylindrical support portion, and the contact between the tablet 21 and the tablet support rod 25 may be improved by inserting the tablet 21 into the cylinder.

  Further, in each of the above-described embodiments, the example in which the present invention is applied to the long size tablet 21 has been described, but the present invention can also be applied to the short size tablet 21. Moreover, although the tablet which carried out the sintering shaping | molding with the powder of zinc oxide and gallium oxide was used as an evaporation source, if it forms the workpiece | work W into a film, it will not be limited to this.

  Further, in each of the above-described embodiments, the tablets 21 and 51 are accommodated in the center of the hearts 5 and 35, and the examples in which the hearts 5 and 35 and the tablets 21 and 51 are arranged close to each other have been described. If 21 and 51 are arrange | positioned in proximity to the hearths 5 and 35, it is not limited to the structure which accommodates the tablets 21 and 51 in the center of the hearths 5 and 35.

  The embodiment disclosed this time is illustrative in all respects and is not limited to this embodiment. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims for patent.

  As described above, the present invention has an effect that a stable film formation rate can be obtained, and a stable discharge can be obtained without performing a preliminary work for forming an electrical path. This is useful for a push-up type ion plating apparatus.

It is a figure which shows 1st Embodiment of the ion plating apparatus which concerns on this invention, and is a schematic diagram of an ion plating apparatus. It is a figure which shows 1st Embodiment of the ion plating apparatus which concerns on this invention, and is a schematic diagram which shows the tablet support structure of a tablet support bar. It is a figure which shows 1st Embodiment of the ion plating apparatus which concerns on this invention, and is explanatory drawing of the movement path | route of the negative charge at the time of plasma beam irradiation. It is a figure which shows 2nd Embodiment of the ion plating apparatus which concerns on this invention, and is a schematic diagram of an ion plating apparatus. It is a figure which shows the modification of the ion plating apparatus which concerns on this invention.

Explanation of symbols

1, 31, 61 Ion plating device 3, 33 Vacuum chamber (chamber)
4, 34 Plasma gun (plasma beam source)
5, 35 Hearth 6, 36 Transport device 16, 36 DC power supply 17, 47 Hearth resistance (resistance)
21, 51 tablet (evaporation source)
23, 53 Insulation pipe 25, 55 Tablet support rod (evaporation source support)
25a Rod-shaped part 25b Support part 25c Holding part 25d Support surface 27 Conductive sheet 48 Ammeter (current detection part)
49 Resistance control unit W Work P Plasma beam

Claims (6)

A chamber, a plasma beam generation source that functions as a cathode and generates a plasma beam in the chamber, a hearth that functions as an anode and is irradiated with the plasma beam in the chamber, and a film that is disposed in proximity to the hearth An evaporation source support for supporting the evaporation source for exposure so as to be exposed in the chamber,
The evaporation source support is conductive,
The ion plating apparatus according to claim 1, wherein the hearth is insulated from the evaporation source in the chamber and electrically connected to the evaporation source support portion through a resistor outside the chamber. The resistor is a variable resistor,
A current detector for detecting a current flowing through the evaporation source;
The ion plating apparatus according to claim 1, further comprising a resistance value control unit configured to control a resistance value of the resistor based on a detection result of the current detection unit. The current detection unit detects a current flowing through the evaporation source during film formation,
The ion plating apparatus according to claim 2, wherein the resistance value control unit controls a resistance value of the resistance during film formation.   The ion plating apparatus according to any one of claims 1 to 3, wherein a conductive surface having flexibility is provided on a support surface that supports the evaporation source of the evaporation source support portion.   The ion plating apparatus according to any one of claims 1 to 4, wherein the evaporation source support portion includes a holding portion that elastically holds the evaporation source.   The ion plating apparatus according to claim 5, wherein the hearth is provided on a side surface of the chamber.

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