KR20210006108A - Negative ion generation apparatus - Google Patents

Abstract

Provided is a negative ion generating device capable of irradiating a negative ion to an object at an appropriate timing. A control unit (50) controls the application of a voltage by a voltage application unit (90) based on a measurement result of a potential measurement unit (110) after stopping the generation of plasma (P) by a plasma gun (7). Therefore, the control unit (50) can irradiate the negative ion to a film forming object (11) at the timing where a large amount of electrons can avoid being irradiated to the object.

Description

Negative ion generation apparatus

The present invention relates to an apparatus for generating negative ions.

The one described in Patent Document 1 is known as a negative ion generating device that generates negative ions using plasma. This negative ion generating device generates a plasma in a chamber and supplies a raw material of the negative ions into the chamber to generate negative ions in the chamber.

Patent Document 1: Japanese Laid-Open Patent Publication No. 2017-025407

Here, when plasma is generated in the chamber, electrons as well as negative ions are generated in the chamber. For example, in a state in which negative ions are not generated in the chamber and a large amount of electrons are present, when negative ions are irradiated to the object, electrons are also irradiated to the object. When a large amount of electrons is irradiated to the object, there is a possibility that the object becomes high temperature. Therefore, when irradiating negative ions to an object, it is required to irradiate negative ions at an appropriate timing to avoid irradiation of a large amount of electrons onto the object.

Accordingly, an object of the present invention is to provide a negative ion generating apparatus capable of irradiating negative ions onto an object at an appropriate timing.

In order to solve the above problems, the negative ion generating apparatus according to the present invention is a negative ion generating apparatus that generates negative ions using plasma and irradiates the target, and a chamber that houses the object and generates negative ions inside. Wow, in the chamber, a plasma gun that generates plasma, a potential measurement unit that measures a potential in the chamber, a voltage application unit capable of applying a positive voltage to an object, and a control unit that controls a negative ion generating device. And the control unit controls application of the voltage by the voltage application unit based on the measurement result of the electric potential measurement unit after stopping plasma generation of the plasma gun.

In the negative ion generating apparatus according to the present invention, the plasma gun generates plasma inside the chamber, thereby generating negative ions inside the chamber. Further, the voltage application unit applies a positive voltage to the object, and the negative ions in the chamber are guided toward the object, so that the negative ions are irradiated to the object. Here, after the plasma generation of the plasma gun is stopped, the electrons tend to adhere to the raw material of the negative ions, so that the generation of negative ions proceeds. Therefore, since negative ions and electrons increase or decrease in the chamber, the potential inside the chamber fluctuates. For this reason, it is possible to grasp an appropriate timing for irradiating negative ions onto the object based on the measurement result of the potential measuring unit that measures the potential in the chamber. Accordingly, the control unit controls the application of the voltage by the voltage application unit based on the measurement result of the electric potential measurement unit after the plasma gun stops generating plasma. Thereby, the control unit can irradiate the object with negative ions at a timing capable of avoiding irradiation of a large amount of electrons onto the object. As described above, negative ions can be irradiated onto the object at an appropriate timing.

The control unit may start application of the voltage by the voltage application unit at a timing when the potential rises and falls based on the measurement result of the potential measurement unit. The timing at which the potential rises and falls is the timing at which generation of negative ions proceeds to some extent after the generation of plasma is stopped. Accordingly, the control unit can irradiate the object with the negative ions at the timing at which the generation of the negative ions proceeds by starting the application of the voltage at this timing.

The control unit may start application of the voltage by the voltage application unit at a timing when the potential falls and the peak of the fall is reached based on the measurement result of the potential measurement unit. The timing at which the peak of the potential drop is reached is close to the timing at which the amount of generated negative ions becomes a peak after the generation of plasma is stopped. Therefore, the control unit can irradiate the target object with negative ions at the timing when many negative ions exist by starting the application of the voltage at this timing.

The control unit may start application of the voltage by the voltage application unit at a timing when the potential increases based on the measurement result of the electric potential measurement unit. In this case, it is possible to irradiate the object with more negative ions than when the application is started at the timing when the potential rises and falls, and the timing when the potential falls and reaches the peak of falling. However, compared to the case where application is initiated at the timing when the potential rises and falls, and the timing when the potential falls and reaches the peak of falling, there is a possibility of irradiation with a large number of electrons, so an object that allows electron irradiation It is preferable to be.

The electric potential measuring unit may measure the electric potential of the space around the object. In this case, it becomes possible to perform control based on the situation in the vicinity of the object to be irradiated with negative ions.

The control unit repeats the generation of the plasma by the plasma gun and the generation of negative ions by stopping the generation of the plasma. For each generation of negative ions, the potential measurement unit measures the electric potential, and the control unit measures the electric potential. The voltage application by the voltage application unit may be controlled based on the negative measurement result. Application of the voltage by the voltage application unit affects the state of the plasma in the chamber. For example, even if the operating conditions for the first generation of negative ions and the second generation of negative ions are the same, the timing at which negative ions are generated after the plasma generation is stopped may change between the two. have. Therefore, in each generation of negative ions, measurement by the potential measuring unit and control of application of voltage based on the measurement result are performed, so that the negative ions can be irradiated to the object at an appropriate timing.

Advantageous Effects of Invention According to the present invention, it is possible to provide a negative ion generating device capable of irradiating negative ions onto an object at an appropriate timing.

1 is a schematic cross-sectional view showing a configuration of a film forming/negative ion generating apparatus according to an embodiment of the present invention, and is a diagram showing an operating state in a film forming processing mode.
FIG. 2 is a schematic cross-sectional view showing the configuration of the film forming/negative ion generating device of FIG. 1, and is a diagram showing an operating state in a negative ion generating mode.
3 is a flowchart showing the control contents of the control unit in the film forming/negative ion generating apparatus according to the embodiment of the present invention.
In Fig. 4, Fig. 4(a) is a graph showing the floating potential at a predetermined location in the space of the vacuum chamber during generation of negative ions, and Fig. 4(b) is a graph showing the floating potential in the space of the vacuum chamber. The number of negative ions per unit square area at a predetermined location is shown.
5 is a graph showing a state of a floating potential immediately after plasma generation is stopped.
6 is a diagram showing a modified example of the electrode portion of the potential measuring unit.
7 is a flowchart showing control contents of a control unit in the film forming/negative ion generating apparatus according to the embodiment of the present invention.

Hereinafter, a film forming apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings. However, in the description of the drawings, the same elements are denoted by the same reference numerals, and duplicate descriptions are omitted.

First, a configuration of a film forming/negative ion generating apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. 1 and 2 are schematic cross-sectional views showing the configuration of a film forming/negative ion generating apparatus according to the present embodiment. Fig. 1 shows an operation state in a film forming processing mode, and Fig. 2 shows an operation state in a negative ion generation mode. However, details of the film formation processing mode and the negative ion generation mode will be described later.

As shown in Figs. 1 and 2, the film forming/negative ion generating apparatus 1 of the present embodiment is an ion plating apparatus used in a so-called ion plating method. However, for convenience of explanation, FIGS. 1 and 2 show the XYZ coordinate system. The Y-axis direction is a direction in which a film-forming object described later is conveyed. The X-axis direction is a position where the film-forming object and the Haas mechanism described later face each other. The Z-axis direction is a direction orthogonal to the Y-axis direction and the X-axis direction.

The film-forming/negative ion generating device 1 is a so-called horizontal film-forming/negative ion generating device in which the film-forming object 11 is arranged and conveyed in the vacuum chamber 10 so that the plate thickness direction of the film-forming object 11 is substantially vertical. You can open it. In this case, the Z-axis and Y-axis directions are horizontal, and the X-axis direction is a vertical direction and a plate thickness direction. However, in the film-forming/negative ion generating device 1, the film-forming object 11 is upright or upright so that the plate thickness direction of the film-forming object 11 is in the horizontal direction (X-axis direction in Figs. 1 and 2). It may be a so-called vertical film formation/negative ion generating device in which the film-forming object 11 is disposed in and conveyed in the vacuum chamber 10 in a state inclined from. In this case, the X-axis direction is the horizontal direction and the plate thickness direction of the film-forming object 11, the Y-axis direction is the horizontal direction, and the Z-axis direction is the vertical direction. A film formation/negative ion generation apparatus according to an embodiment of the present invention will be described below by taking a horizontal film formation/negative ion generation apparatus as an example.

The film forming/negative ion generating device 1 includes a vacuum chamber 10, a conveying mechanism 3, a film forming unit 14, a negative ion generating unit 24, a voltage applying unit 90, and a potential measuring unit 110. , And a control unit 50.

The vacuum chamber 10 is a member for accommodating the film-forming object 11 and performing film-forming processing. The vacuum chamber 10 includes a transfer chamber 10a for conveying a film-forming object 11 on which a film of a film-forming material Ma is formed, a film-forming chamber 10b for diffusing the film-forming material Ma, and a plasma gun ( It has a plasma sphere 10c for accommodating the plasma P irradiated from 7) in the form of a beam in the vacuum chamber 10. The transfer chamber 10a, the film formation chamber 10b, and the plasma sphere 10c are in communication with each other. The transfer chamber 10a is set along a predetermined transfer direction (arrow A in the figure) (along the Y axis). Further, the vacuum chamber 10 is made of a conductive material and is connected to a ground potential.

The film forming chamber 10b is a wall portion 10W, a pair of side walls along the conveying direction (arrow A), and a pair of side walls 10h along the direction intersecting with the conveying direction (arrow A) (Z-axis direction). , 10i), and a bottom wall 10j disposed to intersect with the X-axis direction.

The conveying mechanism 3 conveys the film-forming object supporting member 16 that supports the film-forming object 11 in a state opposite to the film-forming material Ma in a transport direction (arrow A). For example, the film-forming object supporting member 16 is a frame body that supports the outer circumferential edge of the film-forming object 11. The conveying mechanism 3 is constituted by a plurality of conveying rollers 15 provided in the conveying chamber 10a. The conveying rollers 15 are arranged at equal intervals along the conveying direction (arrow A), and conveyed in the conveying direction (arrow A) while supporting the film-forming object supporting member 16. However, as the film-forming object 11, for example, a plate-like member such as a glass substrate or a plastic substrate is used.

Subsequently, the configuration of the film forming portion 14 will be described in detail. The film-forming part 14 adheres particles of the film-forming material Ma to the film-forming object 11 by an ion plating method. The film forming section 14 includes a plasma gun 7, a steering coil 5, a hearth mechanism 2, and a ring hearth 6.

The plasma gun 7 is, for example, a pressure gradient type plasma gun, and its body portion is connected to the film formation chamber 10b through a plasma port 10c provided on the side wall of the film formation chamber 10b. The plasma gun 7 generates plasma P in the vacuum chamber 10. The plasma P generated by the plasma gun 7 is emitted in the form of a beam from the plasma sphere 10c into the film formation chamber 10b. As a result, plasma P is generated in the film formation chamber 10b.

One end of the plasma gun 7 is closed by a cathode 60. Between the cathode 60 and the plasma sphere 10c, a first intermediate electrode (grid) 61 and a second intermediate electrode (grid) 62 are concentrically disposed. An annular permanent magnet 61a for converging the plasma P is embedded in the first intermediate electrode 61. An electromagnet coil 62a is also embedded in the second intermediate electrode 62 to converge the plasma P. However, the plasma gun 7 also has a function as a negative ion generating unit 24 to be described later. This detail will be described later in the description of the negative ion generation unit 24.

The steering coil 5 is provided around a plasma sphere 10c equipped with a plasma gun. The steering coil 5 guides the plasma P into the film forming chamber 10b. The steering coil 5 is excited by a power supply for a steering coil (not shown).

The hearth mechanism 2 supports the film forming material Ma. The Haas mechanism 2 is provided in the film formation chamber 10b of the vacuum chamber 10 and is arranged in the negative direction of the X-axis direction as viewed from the conveyance mechanism 3. The Haas mechanism 2 is a main anode that guides the plasma P emitted from the plasma gun 7 to the film forming material Ma, or the plasma P emitted from the plasma gun 7 is guided. It has a main anode, the main heart (17).

The main hearth 17 has a normal filling portion 17a extending in the positive direction in the X-axis direction filled with the film-forming material Ma, and a flange portion 17b protruding from the filling portion 17a. Since the main hearth 17 is maintained at a positive potential with respect to the ground potential of the vacuum chamber 10, it sucks the plasma P of the negative potential. A through hole 17c for filling the film-forming material Ma is formed in the charging portion 17a of the main hearth 17 to which the plasma P is incident. Then, the tip portion of the film formation material Ma is exposed to the film formation chamber 10b at one end of the through hole 17c.

Examples of the film forming material Ma include transparent conductive materials such as ITO and ZnO, and insulating sealing materials such as SiON. When the film forming material Ma is made of an insulating material, when the plasma P is irradiated to the main hearth 17, the main hearth 17 is heated by the current from the plasma P, so that the film forming material Ma is The tip portion evaporates or sublimates, and the film-forming material particles (evaporation particles) Mb ionized by the plasma P diffuse into the film-forming chamber 10b. In addition, when the film-forming material Ma is made of a conductive material, when the plasma P is irradiated to the main hearth 17, the plasma P directly enters the film-forming material Ma, and the tip of the film-forming material Ma The portion is heated to evaporate or sublimate, and the film-forming material particles Mb ionized by the plasma P diffuse into the film-forming chamber 10b. The film-forming material particles Mb diffused into the film-forming chamber 10b move in the positive X-axis direction of the film-forming chamber 10b, and adhere to the surface of the film-forming object 11 in the transfer chamber 10a. However, the film-forming material Ma is a solid material molded into a cylindrical shape of a predetermined length, and a plurality of film-forming materials Ma are filled into the Haas mechanism 2 at once. Then, in accordance with the consumption of the film-forming material Ma, the film-forming material Ma is added to the hearth mechanism so that the tip portion of the film-forming material Ma at the foremost end maintains a predetermined positional relationship with the upper end of the main hearth 17. It is extruded sequentially from the X-axis direction side of 2)

The ringhas 6 is an auxiliary anode having an electromagnet for inducing plasma P. The ring hearth 6 is disposed around the charging portion 17a of the main hearth 17 that supports the film forming material Ma. The ringhas (6) has an annular coil (9), an annular permanent magnet portion (20) and an annular vessel (12), and the coil (9) and permanent magnet portion (20) are accommodated in the vessel (12). Has been. In this embodiment, as viewed from the conveying mechanism 3, the coil 9 and the permanent magnet portion 20 are arranged in the order of the X-axis portion, but the permanent magnet portion 20 and the coil 9 They may be installed in order. Depending on the magnitude of the current flowing through the coil 9, the ringhas 6 determines the direction of the plasma P incident on the film forming material Ma or the direction of the plasma P incident on the main heart 17. Control.

Subsequently, the configuration of the negative ion generation unit 24 will be described in detail. The negative ion generation unit 24 includes a plasma gun 7, a source gas supply unit 40, and a circuit unit 34. In addition, some of the components of the control unit 50 also function as the negative ion generation unit 24. However, some functions included in the control unit 50 and the circuit unit 34 also belong to the film forming unit 14 described above.

The plasma gun 7 is the same as the plasma gun 7 included in the film forming section 14 described above. That is, in the present embodiment, the plasma gun 7 of the film forming portion 14 is used both with the plasma gun 7 of the negative ion generating portion 24. The plasma gun 7 functions not only as the film-forming part 14 but also as the negative ion generating part 24. However, in the film-forming part 14 and the negative ion generating part 24, you may have different and separate plasma guns.

The plasma gun 7 generates plasma P intermittently in the film formation chamber 10b. Specifically, the plasma gun 7 is controlled to generate the plasma P intermittently in the film formation chamber 10b by the control unit 50 described later. This control will be described in detail in the description of the control unit 50 described later.

The source gas supply unit 40 is disposed outside the vacuum chamber 10. The source gas supply unit 40 supplies source gas into the vacuum chamber 10 through a gas supply port 41 provided in a side wall (for example, the side wall 10h) of the film forming chamber 10b. As the raw material gas, for example, oxygen gas, which is a raw material gas of oxygen negative ions, may be employed. The source gas supply unit 40 starts supply of oxygen gas when it is switched from the film forming processing mode to the negative ion generation mode, for example. Further, the source gas supply unit 40 may continue to supply oxygen gas in both the film forming processing mode and the negative ion generation mode.

The position of the gas supply port 41 is preferably a position near the boundary between the film formation chamber 10b and the transfer chamber 10a. In this case, since the oxygen gas from the source gas supply unit 40 can be supplied near the boundary between the film formation chamber 10b and the transfer chamber 10a, negative ions described later are generated near the boundary. Therefore, the generated negative ions can be suitably attached to the film-forming object 11 in the transfer chamber 10a. However, the position of the gas supply port 41 is not limited to the vicinity of the boundary between the film formation chamber 10b and the transfer chamber 10a.

The circuit unit 34 has a variable power supply 80, a first wiring 71, a second wiring 72, resistors R1 to R4, and short circuit switches SW1 and SW2.

The variable power supply 80 interposes the vacuum chamber 10 at the ground potential, and applies a negative voltage to the cathode 60 of the plasma gun 7 and a constant voltage to the main hearth 17 of the hash mechanism 2. Approved. Thereby, the variable power supply 80 generates a potential difference between the cathode 60 of the plasma gun 7 and the main hearth 17 of the hearth mechanism 2.

The first wiring 71 electrically connects the cathode 60 of the plasma gun 7 to the negative potential side of the variable power supply 80. The second wiring 72 electrically connects the main hearth 17 (positive electrode) of the hearth mechanism 2 to the positive potential side of the variable power source 80.

The resistor R1 has one end electrically connected to the first intermediate electrode 61 of the plasma gun 7 and the other end electrically connected to the variable power source 80 through the second wiring 72. have. That is, the resistor R1 is connected in series between the first intermediate electrode 61 and the variable power supply 80.

The resistor R2 has one end electrically connected to the second intermediate electrode 62 of the plasma gun 7 and the other end electrically connected to the variable power supply 80 through the second wiring 72. have. That is, the resistor R2 is connected in series between the second intermediate electrode 62 and the variable power supply 80.

The resistor R3 has one end electrically connected to the wall portion 10W of the film forming chamber 10b, and the other end electrically connected to the variable power source 80 via the second wiring 72. That is, the resistor R3 is connected in series between the wall portion 10W of the film forming chamber 10b and the variable power supply 80.

The resistor R4 has one end electrically connected to the ringhas 6 and the other end electrically connected to the variable power supply 80 via a second wiring 72. That is, the resistor R4 is connected in series between the ringhas 6 and the variable power supply 80.

The shorting switches SW1 and SW2 are switching units that are switched to ON/OFF states by receiving command signals from the control unit 50 described above, respectively.

The shorting switch SW1 is connected in parallel to the resistor R2. The short-circuit switch SW1 switches the ON/OFF state by the control unit 50 depending on whether it is in the film forming processing mode or the negative ion mode. Here, the film-forming processing mode is a mode in which a film-forming process is performed on the film-forming object 11 in the vacuum chamber 10. The negative ion generation mode is a mode in which negative ions are generated to adhere to the surface of the film formed on the film-forming object 11 in the vacuum chamber 10. The shorting switch SW1 is turned off in the film forming processing mode. Accordingly, in the film forming processing mode, since the second intermediate electrode 62 and the variable power supply 80 are electrically connected to each other through the resistor R2, the second intermediate electrode 62 and the variable power supply 80 are It is difficult for current to flow. As a result, the plasma P from the plasma gun 7 is emitted into the vacuum chamber 10 and enters the film forming material Ma (see Fig. 1). However, when the plasma P from the plasma gun 7 is emitted into the vacuum chamber 10, instead of making it difficult to flow current to the second intermediate electrode 62, it is transferred to the first intermediate electrode 61. You may make it difficult to flow the current of. In this case, the shorting switch SW1 is connected to the first intermediate electrode 61 side instead of the second intermediate electrode 62 side.

On the other hand, in the negative ion generation mode, the shorting switch SW1 is turned on/off by the control unit 50 to intermittently generate the plasma P from the plasma gun 7 in the vacuum chamber 10. The state is switched at predetermined intervals. When the short-circuit switch SW1 is switched to the ON state, the electrical connection between the second intermediate electrode 62 and the variable power supply 80 is short-circuited, so that between the second intermediate electrode 62 and the variable power supply 80 Current flows in. That is, a short-circuit current flows through the plasma gun 7. As a result, the plasma P from the plasma gun 7 is not emitted into the vacuum chamber 10.

When the short-circuit switch SW1 is switched to the OFF state, the second intermediate electrode 62 and the variable power supply 80 are electrically connected to each other through the resistor R2, so that the second intermediate electrode 62 and the variable power supply 80 It is difficult for current to flow between ). As a result, the plasma P from the plasma gun 7 is emitted into the vacuum chamber 10. In this way, the ON/OFF state of the shorting switch SW1 is switched by the control unit 50 at predetermined intervals, so that the plasma P from the plasma gun 7 is intermittently generated in the vacuum chamber 10. That is, the short-circuit switch SW1 is a switching unit that switches between supplying and cutting off the plasma P into the vacuum chamber 10.

The shorting switch SW2 is connected in parallel to the resistor R4. The short-circuit switch SW2 is switched ON/OFF by the control unit 50 according to whether the standby mode or the film forming processing mode is a state before transport of the film forming object 11 before entering the film forming processing mode. . The short-circuit switch SW2 is turned on in the standby mode. As a result, since the electrical connection between the ringhas 6 and the variable power supply 80 is short-circuited, it is easier to pass a current through the ringhas 6 than the main has 17, and wasteful consumption of the film-forming material (Ma). Can be prevented.

On the other hand, the shorting switch SW2 is turned off in the film forming processing mode. As a result, since the ringhas 6 and the variable power supply 80 are electrically connected through the resistor R4, it is easier to pass current to the main hose 17 than the ringhas 6, and the emission direction of the plasma P Can be suitably directed to the film-forming material (Ma). However, in the negative ion generation mode, the short-circuit switch SW2 may be in either an ON state or an OFF state.

The voltage application unit 90 can apply a positive voltage to the film-forming object (object) 11 after film formation. The voltage application unit 90 includes a bias circuit 35 and a trolley line 18.

The bias circuit 35 is a circuit for applying a positive bias voltage to the object 11 after film formation. The bias circuit 35 electrically connects the bias power supply 27, which applies a positive bias voltage (hereinafter, simply referred to as “bias voltage”) to the film-forming object 11, and the bias power supply 27 and the trolley line 18. It has a 3rd wiring 73 to be connected by way, and a shorting switch SW3 provided in the 3rd wiring 73. The bias power supply 27 applies, as a bias voltage, a voltage signal (periodic electric signal) which is a square wave that periodically increases or decreases. The bias power supply 27 is configured so that the frequency of the applied bias voltage can be changed under the control of the control unit 50. The third wiring 73 has one end connected to the positive potential side of the bias power supply 27 and the other end connected to the trolley wire 18. Thereby, the 3rd wiring 73 electrically connects the trolley line 18 and the bias power supply 27.

The shorting switch SW3 is connected in series between the trolley line 18 and the positive potential side of the bias power supply 27 via a third wiring 73. The short-circuit switch SW3 is a switching unit that switches whether or not a bias voltage is applied to the trolley line 18. The short-circuit switch SW3 switches its ON/OFF state by the control unit 50. The shorting switch SW3 is turned on at a predetermined timing in the negative ion generation mode. When the short-circuit switch SW3 is turned on, the trolley line 18 and the positive potential side of the bias power supply 27 are electrically connected to each other, and a bias voltage is applied to the trolley line 18.

On the other hand, the shorting switch SW3 is turned off at a predetermined timing in the film formation processing mode and in the negative ion generation mode. When the short-circuit switch SW3 is turned off, the trolley wire 18 and the bias power supply 27 are electrically cut off from each other, and the bias voltage is not applied to the trolley wire 18. However, details of the timing of applying the bias voltage will be described later.

The trolley wire 18 is a temporary wire for feeding power to the object supporting member 16 to be formed. The trolley wire 18 is provided in the conveyance chamber 10a by extending it in the conveyance direction (arrow B). The trolley line 18 makes power to the film-forming object support member 16 through the power supply brush 42 by contacting the power supply brush 42 provided on the film-forming object support member 16. The trolley wire 18 is made of, for example, a stainless steel wire.

The electric potential measuring unit 110 measures electric potential in the vacuum chamber 10. The electric potential measuring unit 110 measures electric potential of the space around the film-forming object 11. The electric potential measuring unit 110 includes an electric potential detecting unit 111 and an electrode unit 112. The potential detection unit 111 is electrically connected to the electrode unit 112. The potential detection unit 111 detects a value of the floating potential at the position where the electrode unit 112 is provided, based on the potential of the electrode unit 112. The potential detection unit 111 transmits the detected value to the control unit 50 as a measured value.

The electrode part 112 is a member that enters the inner space of the outer rotor of the vacuum chamber 10. The electrode portion 112 is disposed at a position that does not interfere with the moving film-forming object supporting member 16. The tip portion 112a of the electrode portion 112 is disposed in a space around the object 11. The tip portion 112a of the electrode portion 112 is disposed in the transfer chamber 10a of the vacuum chamber 10. In addition, the tip portion 11a is near a communication portion between the transfer chamber 10a and the film forming chamber 10b, and is disposed substantially at the same position as the film forming object 11 in the Z-axis direction.

However, among the electrode portions 112, portions other than the tip portion 112a may be covered with an insulating member. For example, as shown in FIG. 6, a region inside the electrode portion 112 than the wall portion of the vacuum chamber 10 may be covered with the insulating member 140. Further, only the tip portion 112a may be exposed from the insulating member 140 into the space of the vacuum chamber 10. In this case, since the floating potential is not detected except for the tip portion 112a, the potential at a desired location can be intensively measured.

The control unit 50 is a device that controls the entire film formation/negative ion generating device 1, and is composed of a CPU, RAM, ROM, input/output interface, and the like. The control unit 50 is disposed outside the vacuum chamber 10. Further, the control unit 50 includes a mode switching unit 51 for switching the film formation processing mode and the negative ion generation mode, a plasma control unit 52 for controlling the generation of plasma P by the plasma gun 7, and A voltage control unit 53 that controls application of a voltage by the voltage application unit 90 is provided.

When the mode switching unit 51 of the control unit 50 is set to the negative ion generation mode, the control unit 50 controls the source gas supply unit 40 to supply oxygen gas into the film formation chamber 10b. Subsequently, the plasma control unit 52 of the control unit 50 controls the plasma gun 7 to intermittently generate the plasma P from the plasma gun 7 in the film formation chamber 10b. For example, by switching the ON/OFF state of the shorting switch SW1 at predetermined intervals by the control unit 50, the plasma P from the plasma gun 7 is intermittently generated in the film formation chamber 10b. do.

When the short-circuit switch (SW1) is in the ON state, since the plasma P from the plasma gun 7 is not emitted into the film formation chamber 10b, the electron temperature of the plasma P in the film formation chamber 10b Falls sharply. For this reason, electrons of the plasma P are liable to adhere to the particles of the oxygen gas supplied into the film formation chamber 10b in the above-described source gas supply step S21. As a result, negative ions are efficiently generated in the film formation chamber 10b.

The control unit 50 controls the application of the voltage by the voltage application unit 90 based on the measurement result of the electric potential measurement unit 110 after stopping the generation of the plasma P by the plasma gun 7 . The control unit 50 starts application of the voltage by the voltage application unit 90 at a predetermined timing based on the measurement result of the electric potential measurement unit 110. However, the timing at which the voltage application by the voltage applying unit 90 starts is set in advance by the control unit 50.

Here, the relationship between generation of plasma P and generation of negative ions will be described with reference to FIGS. 4 and 5. The solid line in Fig. 4A is a graph showing the floating potential at a predetermined location in the space of the vacuum chamber 10 during generation of negative ions. When electrons or negative ions in the vacuum chamber 10 increase, the floating potential rises, and when it decreases, it falls. 4B shows the number of negative ions per unit square area at a predetermined location in the space of the vacuum chamber 10. 5 is a graph showing a state of a floating potential immediately after plasma generation is stopped. In Fig. 4, it is assumed that when the time is "0", the generation of the plasma P starts, and when the time is "t1", the generation of the plasma is stopped. However, as shown in Fig. 4A, at the moment when the plasma P is stopped, the floating potential rapidly rises. As shown in Fig. 4B, after stopping the plasma P, the amount of negative ions rapidly decreases, and after that, it increases significantly at time t3, reaching a peak of rising at time t2. At a time corresponding to time t3 in Fig. 4A, the floating potential has reached a peak of rising and then falling.

As shown in Fig. 5, after the plasma P is stopped, the floating potential rapidly rises in the section E1 and gradually rises in the section E2. The floating potential reaches a peak of rising around time t3 and then falls in the section E3. The falling floating potential reaches a peak of falling in the vicinity of time t2, and after that, the floating potential gradually rises after the section E4. The section E3 is also a section in which the amount of negative ions rapidly increases (see FIG. 4(b)). In addition, the section E3 is considered to be a section in which the amount of electrons is decreasing because the amount of negative ions is increasing while the floating potential is falling.

From the time t1 through the time t3, in a vacuum chamber 10 is Ar plasma (Ar ^+, e ^-) is the residue of. Even though the short-circuit switch SW1 is short-circuited, it can be said that the voltage between the main hearth 17 and the second intermediate electrode 62 is positive. For example, Ar ⁺ + e ^- → e by extinction flowing in the vacuum chamber 10, and a potential measuring unit 110 by haegam Ar ^- by reducing the amount of go. On the other hand, if the electron temperature is lowered (O ₂ * is the active state of O ₂ )

^{_{O 2 * + e - → O}} - + O ( gap property electron attachment)

O + e ^- → O ^- (E end)

The reaction of the like proceeds, and O ^−, which is slower than the former, is produced. e ^- the speed of O ^- because of the fast than just discard flow into the vacuum chamber (10), O ^- is out diffused due to the slow speed with the speed of the gas temperature. Until time t3, since there is a potential difference between the main hearth 17 and the second intermediate electrode 62, e ^- and O ^- are attracted to the plasma (P) side in the vacuum chamber 10, and are turned off after time t3. Since the power is lost, e ^- and O ^- diffuse. Since the speed is greatly different between e ^- and O ^- , the slow O ^- remains, and the O ^- charges negative. O ^- the behavior of the floating potential, such as 4, also by destruction proceeds simultaneously ^- the creation and Ar ⁺ + e ^- → Ar, O ⁺ + e ^- → O, O ₂ ⁺ + e ^- → O _2, such as the e Show. Considering the balance between plasma generation and extinction and the collision of e ^- , only O ^- and O ₂ ^- survive under negative charges. Since the O ^- side is more than 90%, most are O ^- . Therefore, even though the plasma (P) is turned off, that is, the electron supply has disappeared, charging the negative is also O ^- from the above. do.

The control unit 50 starts application of the voltage by the voltage application unit 90 at the timing when the potential rises and falls based on the measurement result of the potential measurement unit 110. In the example shown in Fig. 5, the sections in which the potential rises are sections E1 and E2. The section in which the potential falls is section E3. The voltage control unit 53 of the control unit 50 starts the application of the voltage by the voltage application unit 90 at any one timing in the period E3 (including the time t2 at which the falling peak becomes). The voltage control unit 53 of the control unit 50 may start the application of the voltage by the voltage application unit 90 in a region on the second half side in which generation of negative ions proceeds to some extent in the period E3. Further, the voltage control unit 53 of the control unit 50 may start application of the voltage at a timing when the potential reaches a predetermined threshold value in the section E3.

Further, the control unit 50 may start the application of the voltage by the voltage application unit 90 at the timing when the electric potential falls and the peak of the fall is reached based on the measurement result of the electric potential measurement unit 110. . That is, the voltage control unit 53 of the control unit 50 starts application of the voltage by the voltage application unit 90 at the timing of reaching the falling peak P1 of the floating potential. The control unit 50 monitors the amount of change in the electric potential based on the measurement result from the electric potential measurement unit 110 to grasp that the electric potential has reached the falling peak P1. However, the timing at which the voltage starts to be applied does not have to be completely coincident with the timing at which the potential measured by the potential measuring unit 110 becomes the peak P1, even if it is shifted back and forth from the timing at which the peak P1 becomes. do.

Further, the control unit 50 may start application of the voltage by the voltage application unit 90 at a timing when the potential rises based on the measurement result of the electric potential measurement unit 110. The voltage control unit 53 of the control unit 50 starts application of the voltage by the voltage application unit 90 at the timing of the period E1 or the period E2. The voltage control unit 53 of the control unit 50 may start application of the voltage by the voltage application unit 90 at the timing of the section E2 after a certain period of time has elapsed from the stop of the plasma P.

Next, with reference to the flow diagram shown in FIG. 3, a part of the control contents during the generation of negative ions by the control unit 50 will be described. However, the processing of the control unit 50 is not limited to FIG. 3.

As shown in FIG. 3, the plasma control unit 52 of the control unit 50 starts generation of the plasma P by the plasma gun 7 (step S10). After a certain period of time, the plasma control unit 52 of the control unit 50 stops the generation of the plasma P by the plasma gun 7 (step S20). As a result, in the vacuum chamber 10, a change in the floating potential as shown in Fig. 5 occurs. The voltage control unit 53 of the control unit 50 acquires the measurement result from the electric potential measurement unit 110 (step S30). Next, the voltage control unit 53 of the control unit 50 determines whether or not it is the timing to start application of the voltage by the voltage application unit 90 based on the potential acquired in S30 (step S40).

If it is determined in S40 that it is not the timing of voltage application, the process is repeated again from S30. On the other hand, in S40, when it is determined that the voltage is applied, the voltage control unit 53 of the control unit 50 starts application of the voltage. As a result, a positive bias voltage is applied to the film-forming object 11, so that negative ions in the vacuum chamber 10 are guided to the film-forming object 11.

In Fig. 3, the processing in one batch of the generation of negative ions in the negative ion generation mode, that is, the generation of the plasma P by the plasma gun 7 and the stop of the generation of the plasma P, is performed. Explained. The film-forming/negative ion generating device 1 generates negative ions a plurality of times. That is, the control unit 50 repeatedly generates the plasma P by the plasma gun 7 and generates negative ions by stopping the generation of the plasma P. Therefore, with reference to Fig. 7, the control contents of the control unit 50 during repeated generation of negative ions will be described. In this case, in each generation of negative ions, the potential measurement unit 110 measures the potential, and the control unit 50 performs the voltage application unit 90 based on the measurement result of the potential measurement unit 110 It controls the application of voltage by

As shown in FIG. 7, the same processing as in FIG. 3 is performed from S10 to S50. After S50, the control unit 50 stops application of the voltage by the voltage application unit 90 after a predetermined period of time has elapsed (step S60). Next, the control unit 50 determines whether the negative ion irradiation has ended (step S70). When it is determined in S70 that the negative ion irradiation has ended, the processing shown in Fig. 7 is ended. If it is determined in S70 that the negative ion irradiation has not been completed, the process is repeated again from S10. That is, the control unit 50 generates the plasma P again (step S10), and stops the generation of the plasma P (step S20). At this time, the measurement by the electric potential measurement unit 110 continues, and the control unit 50 acquires the measurement result from the electric potential measurement unit 110 (step S30). In addition, the control unit 50 restarts application of the voltage by the voltage application unit 90 based on the measurement result of the electric potential measurement unit 110 (step S40). In this way, when negative ions are generated, measurement by the potential measuring unit 110 and application of the voltage by the voltage applying unit 90 are repeatedly performed each time.

The action and effect of the film formation/negative ion generating device 1 according to the present embodiment will be described.

In the film forming/negative ion generating apparatus 1, the plasma gun 7 generates the plasma P inside the vacuum chamber 10, so that negative ions can be generated inside the vacuum chamber 10. Further, the voltage application unit 90 applies a positive voltage to the film-forming object 11, and the negative ions in the vacuum chamber 10 are guided toward the film-forming object 11, so that the negative ions are irradiated to the film-forming object 11 . Here, after the plasma gun 7 stops generating the plasma P, since electrons tend to adhere to the raw material of the negative ions, generation of the negative ions proceeds. Accordingly, since negative ions and electrons increase or decrease in the vacuum chamber 10, the potential inside the vacuum chamber 10 fluctuates. For this reason, the appropriate timing for irradiating negative ions onto the film-forming object 11 can be grasped from the measurement result of the potential measuring unit 110 that measures the potential in the vacuum chamber 10. Therefore, the control unit 50 stops the generation of the plasma P by the plasma gun 7 and then applies the voltage by the voltage application unit 90 based on the measurement result of the potential measurement unit 110. Control. Thereby, the control unit 50 can irradiate the film-forming object 11 with negative ions at a timing capable of avoiding irradiation of a large amount of electrons onto the object. As described above, negative ions can be irradiated onto the film-forming object 11 at an appropriate timing.

The control unit 50 may start application of the voltage by the voltage application unit 90 at a timing when the potential rises and falls based on the measurement result of the potential measurement unit 110. The timing at which the potential rises and falls is the timing at which the generation of negative ions proceeds to some extent after the generation of the plasma P is stopped. Accordingly, the control unit 50 can irradiate the film-forming object 11 with the negative ions at the timing at which the generation of negative ions proceeds by starting the application of the voltage at the timing.

The control unit 50 may start application of the voltage by the voltage application unit 90 at a timing when the potential falls and the peak of the fall is reached based on the measurement result of the potential measurement unit 110. The timing at which the peak of the potential fall is reached is close to the timing at which the amount of generated negative ions becomes a peak after the generation of the plasma P is stopped. Accordingly, the control unit can irradiate the film-forming object 11 with the negative ions at the timing when many negative ions exist by starting the application of the voltage at this timing.

The control unit 50 may start application of the voltage by the voltage application unit 90 at a timing when the potential rises based on the measurement result of the electric potential measurement unit 110. In this case, it is possible to irradiate the object with more negative ions than when the application is started at the timing when the potential rises and falls, and the timing when the potential falls and reaches the peak of falling. However, compared to the case where application is initiated at the timing when the potential rises and falls, and the timing when the potential falls and reaches the peak of falling, there is a possibility of irradiation with a large number of electrons, so an object that allows electron irradiation It is preferable to be.

The electric potential measurement unit 110 may measure the electric potential of the space around the film-forming object 11. In this case, it becomes possible to perform control based on the situation in the vicinity of the film-forming object 11 that is an irradiation target of negative ions.

The control unit 50 repeatedly performs generation of the plasma P by the plasma gun 7 and the generation of negative ions by stopping the generation of the plasma P. In each generation of negative ions, the potential The measurement unit 110 measures the potential, and the control unit 50 controls the application of the voltage by the voltage application unit 90 based on the measurement result of the potential measurement unit 110. When the voltage is applied by the voltage application unit 90, the state of the plasma P in the vacuum chamber 10 is affected. For example, even if the operating conditions for the first generation of negative ions and the second generation of negative ions are the same, the timing at which the negative ions are generated after the plasma P is stopped is changed between the two. There are cases. For example, there are cases where the number of electrons decreases in the second time rather than the first time. When the voltage application timing is determined based on the measurement result by the potential measuring unit 110 at the time of generating the first negative ions, and then applying the voltage at the time of generating the second and subsequent negative ions at the same timing, the appropriate timing is given. There is a possibility that negative ion irradiation is not performed (however, such a control method is not excluded from the scope of claim 1). Therefore, as shown in Fig. 7, in each generation of negative ions, measurement by the potential measuring unit 110 and control of application of voltage based on the measurement result are performed, so that the negative ions are transferred to the target object at an appropriate timing. You can check on.

Here, when the voltage value of voltage application is changed during negative ion irradiation, the state of the plasma P changes, and when the voltage value is high, electrons increase. In the case where the potential measurement unit 110 measures the potential in each generation of negative ions, the influence of changing the voltage value applied with such a voltage can be reflected in the control. Thereby, it is possible to respond to changing the negative ion irradiation amount and incident energy in the process.

As described above, one embodiment of the present embodiment has been described, but the present invention is not limited to the above embodiment, and may be modified or applied to others within the scope of not changing the subject matter described in each claim.

Further, in the above embodiment, since the ion plating type film forming apparatus and the negative ion generating apparatus were combined, the plasma P emitted from the plasma gun was guided to the main hearth side. However, the negative ion generating device need not be combined with the film forming device. Therefore, the plasma P may be guided to, for example, an electrode on the wall facing the plasma gun.

For example, in the above embodiment, the plasma gun 7 is a pressure gradient type plasma gun, but the plasma gun 7 only needs to be able to generate plasma in the vacuum chamber 10, and is not limited to the pressure gradient type. Does not.

Further, in the above embodiment, only one set of the plasma gun 7 and the hash mechanism 2 is provided in the vacuum chamber 10, but a plurality of sets may be provided. In addition, plasma P may be supplied from a plurality of plasma guns 7 for one material. In the above embodiment, the ring hearth 6 is provided, but the ring hearth 6 may be omitted by devising the direction of the plasma gun 7 and the position and direction of the material in the hearth mechanism 2.

1 Film formation/negative ion generating device (negative ion generating device)
7 Plasma Gun
10 vacuum chamber
11 Object of the tabernacle
50 control unit
90 voltage application part
110 Potential measurement unit
P plasma

Claims (6)

As a negative ion generating device that generates negative ions using plasma and irradiates the target,
A chamber in which the object is accommodated and the negative ions are generated therein,
In the chamber, a plasma gun for generating the plasma,
An electric potential measuring unit for measuring electric potential in the chamber,
A voltage applying unit capable of applying a positive voltage to the object,
And a control unit for controlling the negative ion generating device,
The control unit, after stopping the generation of the plasma by the plasma gun, controls application of a voltage by the voltage applying unit based on a measurement result of the potential measuring unit. The method of claim 1,
The control unit starts application of a voltage by the voltage applying unit at a timing when the potential rises and falls based on a measurement result of the potential measurement unit. The method of claim 2,
The control unit, based on a measurement result of the potential measuring unit, starts application of a voltage by the voltage applying unit at a timing when the potential falls and a peak of the fall is reached. The method of claim 1,
The control unit, based on a measurement result of the potential measuring unit, starts application of a voltage by the voltage applying unit at a timing when the potential is increased. The method according to any one of claims 1 to 4,
The potential measuring unit measures a potential of a space around the object. The method according to any one of claims 1 to 4,
The control unit repeats the generation of the plasma by the plasma gun and the generation of the negative ions by stopping the generation of the plasma,
In each generation of the negative ions, the potential measurement unit measures the potential, and the control unit controls application of a voltage by the voltage applying unit based on the measurement result of the potential measurement unit. Generating device.

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