TWI700967B - Negative ion generator - Google Patents

Abstract

[Problem] The present invention provides an anion generating device capable of irradiating an object with anion at an appropriate timing. [Solution] After the control unit (50) stops the generation of plasma (P) from the plasma gun (7), based on the measurement result of the potential measuring unit (110), it controls the control based on the voltage of the voltage applying unit (90) Apply. Thereby, the control unit (50) can irradiate the film-forming object (11) with negative ions at a timing that can prevent a large amount of electrons from irradiating the object.

Description

Negative ion generator

The invention relates to a negative ion generating device.

As an anion generator that uses plasma to generate anion, what is described in Patent Document 1 is known. The negative ion generation device generates negative ions in the chamber by generating plasma in the chamber and supplying the raw material of the negative ions into the chamber. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2017-025407

[The problem to be solved by the invention]

Here, if plasma is generated in the chamber, not only negative ions but also electrons are generated in the chamber. For example, in a state where negative ions are not generated in the chamber and there are a lot of electrons, when the negative ions are irradiated to the object, the electrons are also irradiated to the object. If the object is irradiated with a large amount of electrons, the object may become high temperature. Therefore, when the object is irradiated with negative ions, it is required to irradiate the object with the negative ions at an appropriate timing that can prevent a large amount of electrons from irradiating the object.

Therefore, the subject of the present invention is to provide an anion generator capable of irradiating an object with anion at an appropriate timing. [Means to solve the problem]

In order to solve the above-mentioned problems, the negative ion generator of the present invention uses plasma to generate negative ions to irradiate an object, and includes: a chamber that stores the object and generates negative ions inside; and a plasma gun that generates electricity in the chamber Plasma; Potential measuring part, which measures the potential in the chamber; Voltage applying part, which can apply a positive voltage to the object; and Control part, which controls the negative ion generator; The control part stops the plasma gun After the plasma is generated, the application of the voltage by the voltage application unit is controlled based on the measurement result of the potential measurement unit.

In the negative ion generating device of the present invention, the plasma gun generates plasma in the chamber, thereby being able to generate negative ions in the chamber. In addition, by applying a positive voltage to the object by the voltage application unit, the negative ions in the chamber are guided to the object side, and the negative ions are irradiated to the object. Here, after the plasma generation of the plasma gun is stopped, electrons are easily attached to the raw material of negative ions, thereby generating negative ions. Therefore, negative ions and electrons increase or decrease in the chamber, and therefore the potential inside the chamber fluctuates. Therefore, it is possible to grasp the appropriate timing of irradiating the negative ions to the object based on the measurement result of the potential measuring unit that measures the potential in the chamber. Therefore, after the control unit stops the plasma generation of the plasma gun, it controls the application of the voltage by the voltage application unit based on the measurement result of the potential measurement unit. Thereby, the control unit can irradiate the object with negative ions at a timing that can prevent the object from being irradiated with a large amount of electrons. Through the above, it is possible to irradiate the object with negative ions at an appropriate timing.

The control unit may start the application of the voltage by the voltage applying unit based on the measurement result of the electric potential measuring unit at the timing of the electric potential rising and then decreasing. The sequence of potential rise and fall is the sequence of the generation of negative ions to a certain extent after the generation of plasma is stopped. Therefore, by starting the application of the voltage at this timing, the control unit can irradiate the object with negative ions at the timing when the negative ions are generated.

The control unit may start the application of the voltage by the voltage application unit at the timing when the potential drops and reaches the peak of the drop based on the measurement result of the potential measurement unit. The timing to reach the peak of the potential drop is close to the timing when the amount of generated negative ions becomes the peak after plasma generation is stopped. Therefore, by starting the application of the voltage at this timing, the control unit can irradiate the object with negative ions at the timing when there are many negative ions.

The control unit may start the application of the voltage by the voltage application unit at the timing of the potential rise based on the measurement result of the potential measurement unit. At this time, compared to the case where the application is started at the timing of the drop after the potential rises, and the timing of the drop peak after the potential falls, it is possible to irradiate more negative ions to the object. However, compared with the time when the potential rises and then drops, and the potential drops after the peak reaches the peak of the time when the application is started, there is a possibility that a large amount of electrons may be mixed. Therefore, it is possible to allow electrons to be irradiated. good.

The potential measurement unit can measure the potential of the space around the object. At this time, it is possible to perform control based on the situation in the vicinity of the object to be irradiated with negative ions.

The control unit repeatedly generates plasma from the plasma gun and generates negative ions by stopping the generation of the plasma. In each generation of negative ions, the potential measuring unit measures the potential, and the control unit is based on The measurement result of the potential measuring unit is controlled based on the voltage application by the voltage applying unit. If the voltage is applied by the voltage applying part, it will affect 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, between the two, the timing of generation of negative ions after the generation of plasma is stopped may change. Therefore, in each generation of negative ions, it is possible to irradiate the object with negative ions at an appropriate timing by performing the measurement by the potential measurement unit and the control of the voltage application based on the measurement result. [Invention Effect]

According to the present invention, it is possible to provide an anion generator capable of irradiating an object with anion at an appropriate timing.

Hereinafter, a film forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. In addition, in the description of the drawings, the same reference numerals are given to the same elements, and repeated descriptions are omitted.

First, referring to Fig. 1 and Fig. 2, the structure of the film-forming and anion generating device according to the embodiment of the present invention will be described. Fig. 1 and Fig. 2 are schematic cross-sectional views showing the structure of the film-forming and anion generating apparatus of this embodiment. FIG. 1 shows the operation state in the film formation processing mode, and FIG. 2 shows the operation state in the negative ion generation mode. In addition, the 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 and negative ion generator 1 of this embodiment is an ion plating device used for the so-called ion plating method. In addition, for convenience of explanation, the XYZ coordinate system is shown in FIGS. 1 and 2. The Y-axis direction is the direction of conveying the film-forming object described later. The X-axis direction is the position where the film-forming object faces the hearth mechanism described later. The Z-axis direction is a direction orthogonal to the Y-axis direction and the X-axis direction.

The film-forming and anion generating device 1 may be a so-called horizontal film-forming and anion generating device in which the film-forming object 11 is arranged in a vacuum chamber so that the thickness direction of the film-forming object 11 becomes a substantially vertical direction In the room 10 and transported. At this time, the Z-axis and Y-axis directions are horizontal directions, and the X-axis direction becomes the vertical direction and becomes the plate thickness direction. In addition, the film-forming and anion generating device 1 may be a so-called vertical film-forming and anion generating device in which the thickness direction of the film-forming object 11 becomes the horizontal direction (X-axis in FIGS. 1 and 2 In the method of direction), the film-forming object 11 is arranged in the vacuum chamber 10 and transported in a state where the film-forming object 11 is upright or inclined from the state in which it is upright. In this case, the X-axis direction is the horizontal direction and the thickness direction of the film formation target 11, the Y-axis direction is the horizontal direction, and the Z-axis direction is the vertical direction. The film-forming and anion generating apparatus of one embodiment of the present invention will be described below by taking a horizontal film-forming and anion generating apparatus as an example.

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

The vacuum chamber 10 is a member for storing the film-forming object 11 and performing film-forming processing. The vacuum chamber 10 has: a transport chamber 10a for transporting the film-forming object 11 forming a film of the film-forming material Ma, a film-forming chamber 10b for diffusing the film-forming material Ma, and a beam from the plasma gun 7 The irradiated plasma P is received in the plasma port 10c of the vacuum chamber 10. The transfer chamber 10a, the film formation chamber 10b, and the plasma port 10c communicate with each other. The transfer room 10a is set along the predetermined transfer direction (arrow A in the figure) (along the Y axis). In addition, the vacuum chamber 10 is made of a conductive material and is connected to the ground potential.

The film forming chamber 10b, as the wall 10W, has a pair of side walls along the conveying direction (arrow A), a pair of side walls 10h, 10i along a direction (Z-axis direction) crossing the conveying direction (arrow A), and The bottom wall 10j is arranged to cross the X-axis direction.

The transport mechanism 3 transports the film-forming object holding member 16 that holds the film-forming object 11 in a state of being opposed to the film-forming material Ma in the transport direction (arrow A). For example, the film formation object holding member 16 is a frame that holds the outer periphery of the film formation object 11. The transport mechanism 3 is composed of a plurality of transport rollers 15 installed in the transport chamber 10a. The conveyance rollers 15 are arranged at equal intervals in the conveyance direction (arrow A), and convey the film-forming object holding member 16 in the conveyance direction (arrow A). In addition, as the film formation object 11, a plate-shaped member such as a glass substrate or a plastic substrate is used, for example.

Next, the configuration of the film forming section 14 will be described in detail. The film forming part 14 makes the particles of the film forming material Ma adhere to the film forming object 11 by the ion plating method. The film forming part 14 has: a plasma gun 7 and a steering coil 5 , Hearth mechanism 2, and ring hearth 6.

The plasma gun 7 is, for example, a pressure gradient type plasma gun, and its main body is connected to the film forming chamber 10b via a plasma port 10c provided on the side wall of the film forming chamber 10b. The plasma gun 7 generates plasma P in the vacuum chamber 10. The plasma P generated in the plasma gun 7 is emitted in a beam shape from the plasma port 10c into the film forming chamber 10b. Thereby, plasma P is generated in the film forming chamber 10b.

The plasma gun 7 is closed at one end by the cathode 60. Between the cathode 60 and the plasma port 10c, a first intermediate electrode (grid) 61 and a second intermediate electrode (grid) 62 are arranged concentrically. In the first intermediate electrode 61, a ring-shaped permanent magnet 61a for converging the plasma P is installed. An electromagnet coil 62a for converging the plasma P is also installed in the second intermediate electrode 62. In addition, the plasma gun 7 also has a function as a negative ion generator 24 described later. This detailed content will be described later in the description of the negative ion generating unit 24.

The steering coil 5 is arranged around the plasma port 10c where the plasma gun is installed. The steering coil 5 guides the plasma P into the film forming chamber 10b. The steering coil 5 is excited by a power supply (not shown) for the steering coil.

The hearth mechanism 2 holds the film forming material Ma. The hearth mechanism 2 is installed in the film forming chamber 10b of the vacuum chamber 10, and is arranged in the negative direction of the X-axis direction when viewed from the conveying mechanism 3. The hearth mechanism 2 has a main hearth 17 as a main anode that guides the plasma P injected from the plasma gun 7 to the film forming material Ma or the main anode that guides the plasma P injected from the plasma gun 7.

The main hearth 17 has a cylindrical filling part 17a which is filled with the film forming material Ma and extending in the positive direction of the X-axis direction, and a flange part 17b protruding from the filling part 17a. The main hearth 17 is maintained at a positive potential with respect to the ground potential of the vacuum chamber 10, thereby attracting the plasma P of the negative potential. The filling portion 17a of the main hearth 17 into which the plasma P is incident is formed with a through hole 17c for filling the film forming material Ma. The tip of the film forming material Ma is exposed to the film forming 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 composed of an insulating material, if the main hearth 17 is irradiated with plasma P, the current from the plasma P heats the main hearth 17 to evaporate or sublime the tip of the film-forming material Ma. The film-forming material particles (evaporated particles) Mb ionized by the plasma P diffuse in the film-forming chamber 10b. Also, when the film-forming material Ma is composed of a conductive substance, if the main hearth 17 is irradiated with the plasma P, the plasma P directly enters the film-forming material Ma, and the tip portion of the film-forming material Ma is heated to evaporate or sublime. The film-forming material particles Mb ionized by the plasma P diffuse in the film-forming chamber 10b. The film-forming material particles Mb diffused in 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. In addition, the film-forming material Ma is shaped into a cylindrical solid object of a predetermined length, and plural kinds of film-forming materials Ma are filled in the hearth mechanism 2 at a time. And, according to the consumption of the film-forming material Ma, the film-forming material Ma is sequentially extruded from the negative X-axis side of the hearth mechanism 2 so that the tip portion of the film-forming material Ma on the foremost side is kept in contact with the main hearth 17 The established positional relationship at the upper end.

The ring hearth 6 is an auxiliary anode with an electromagnet for inducing plasma P. The ring hearth 6 is arranged around the filling portion 17a of the main hearth 17 holding the film forming material Ma. The ring hearth 6 has an annular coil 9, an annular permanent magnet portion 20 and an annular container 12, and the coil 9 and the permanent magnet portion 20 are accommodated in the container 12. In this embodiment, the coil 9 and the permanent magnet portion 20 are arranged in this order along the negative X-axis direction when viewed from the transport mechanism 3, but the permanent magnet portion 20 and the coil 9 may be arranged in this order along the negative X-axis direction. The ring hearth 6 controls the direction of the plasma P incident on the film-forming material Ma or the direction of the plasma P incident on the main hearth 17 according to the magnitude of the current flowing through the coil 9.

Next, the configuration of the negative ion generating unit 24 will be described in detail. The negative ion generating unit 24 includes a plasma gun 7, a raw material gas supply unit 40, and a circuit unit 34. In addition, some constituent elements of the control unit 50 also function as the negative ion generation unit 24. In addition, the functions of part of the control unit 50 and the circuit unit 34 also belong to the aforementioned film forming unit 14.

The plasma gun 7 is the same as the plasma gun 7 of the aforementioned film forming section 14. That is, in the present embodiment, the plasma gun 7 of the film forming unit 14 also serves as the plasma gun 7 of the negative ion generating unit 24. The plasma gun 7 functions as the film forming unit 14 and also functions as the negative ion generating unit 24. In addition, the film forming part 14 and the negative ion generating part 24 may have separate plasma guns different from each other.

The plasma gun 7 generates plasma P intermittently in the film forming chamber 10b. Specifically, the plasma gun 7 is controlled to generate 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 arranged outside the vacuum chamber 10. The source gas supply unit 40 supplies the source gas into the vacuum chamber 10 through a gas supply port 41 provided in the side wall (for example, side wall 10 h) of the film formation chamber 10 b. As the raw material gas, for example, oxygen, which is a raw material gas of oxygen anions, can be used. The source gas supply unit 40 starts the supply of oxygen when, for example, the film formation processing mode is switched to the negative ion generation mode. In addition, the source gas supply unit 40 may continue to supply oxygen in both the film formation 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 forming chamber 10b and the transfer chamber 10a. At this time, since oxygen from the source gas supply unit 40 can be supplied to the vicinity of the boundary between the film forming chamber 10b and the transfer chamber 10a, the generation of negative ions described later is performed near the boundary. Therefore, the generated negative ions can be appropriately attached to the film-forming object 11 in the transfer chamber 10a. In addition, 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 sandwiches the vacuum chamber 10 at the ground potential, applies a negative voltage to the cathode 60 of the plasma gun 7 and applies a positive voltage to the main hearth 17 of the hearth mechanism 2. Thereby, the variable power source 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 and the negative potential side of the variable power supply 80. The second wiring 72 electrically connects the main hearth 17 (anode) of the hearth mechanism 2 and the positive potential side of the variable power supply 80.

One end of the resistor R1 is electrically connected to the first intermediate electrode 61 of the plasma gun 7, and the other end is electrically connected to the variable power source 80 via the second wiring 72. That is, the resistor R1 is connected in series between the first intermediate electrode 61 and the variable power source 80.

One end of the resistor R2 is electrically connected to the second intermediate electrode 62 of the plasma gun 7, and the other end is electrically connected to the variable power source 80 via the second wiring 72. That is, the resistor R2 is connected in series between the second intermediate electrode 62 and the variable power source 80.

One end of the resistor R3 is electrically connected to the wall portion 10W of the film formation chamber 10 b, and the other end is 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 formation chamber 10b and the variable power source 80.

One end of the resistor R4 is electrically connected to the ring hearth 6, and the other end is electrically connected to the variable power source 80 via the second wiring 72. That is, the resistor R4 is connected in series between the ring hearth 6 and the variable power source 80.

The short-circuit switches SW1 and SW2 are respectively switching parts that are switched to the ON/OFF state by receiving a designated signal from the aforementioned control part 50.

The short-circuit switch SW1 is connected in parallel with the resistor R2. The short-circuit switch SW1 is switched on/off by the control unit 50 depending on whether it is in the film formation processing mode or the negative ion mode. Here, the so-called film-forming processing mode is a mode in which the film-forming object 11 is subjected to film-forming processing in the vacuum chamber 10. The negative ion generation mode is a mode for generating negative ions attached to the surface of the film formed on the film formation object 11 in the vacuum chamber 10. The short-circuit switch SW1 is turned off in the film formation processing mode. Thereby, in the film formation processing mode, the second intermediate electrode 62 and the variable power source 80 are electrically connected to each other via the resistor R2, and therefore, it is difficult for current to flow between the second intermediate electrode 62 and the variable power source 80. As a result, the plasma P from the plasma gun 7 is ejected into the vacuum chamber 10 and enters the film forming material Ma (see FIG. 1). In addition, when the plasma P from the plasma gun 7 is injected into the vacuum chamber 10, it is possible to make the current hard to flow to the first intermediate electrode 61 instead of making the current hard to flow to the second intermediate electrode 62. At this time, the short-circuit switch SW1 is connected to the first intermediate electrode 61 side instead of the second intermediate electrode 62 side.

On the other hand, the short-circuit switch SW1 generates plasma P from the plasma gun 7 intermittently in the vacuum chamber 10 in the negative ion generation mode, and therefore the control unit 50 switches the ON/OFF state 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 source 80 is short-circuited, and therefore, current flows between the second intermediate electrode 62 and the variable power source 80. That is, the short-circuit current flows to the plasma gun 7. As a result, the plasma P from the plasma gun 7 is not ejected 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 source 80 are electrically connected to each other via the resistor R2, and therefore, it is difficult for current to flow between the second intermediate electrode 62 and the variable power source 80. As a result, the plasma P from the plasma gun 7 is ejected into the vacuum chamber 10. In this way, the control unit 50 switches the ON/OFF state of the short-circuit switch SW1 at predetermined intervals, thereby intermittently generating plasma P from the plasma gun 7 in the vacuum chamber 10. That is, the short-circuit switch SW1 is a switching part that switches the supply and cut-off of the plasma P in the vacuum chamber 10.

The short-circuit switch SW2 is connected in parallel with the resistor R4. The short-circuit switch SW2 is switched to the ON/OFF state by the control unit 50 depending on whether it is in the state before the film formation target 11 is transported before the film formation process mode, that is, the standby mode or the film formation process mode. The short-circuit switch SW2 is in the ON state in the standby mode. As a result, the electrical connection between the ring hearth 6 and the variable power source 80 is short-circuited. Therefore, compared to the main hearth 17, the current is more likely to flow to the ring hearth 6, thereby preventing unnecessary consumption of the film forming material Ma. .

On the other hand, the short-circuit switch SW2 is in the OFF state in the film formation processing mode. Thereby, the ring hearth 6 and the variable power source 80 are electrically connected via the resistor R4, so that the current flows more easily to the main hearth 17 than the ring hearth 6, so that the injection direction of the plasma P can be appropriately directed toward the Membrane material Ma. In addition, the short-circuit switch SW2 may be in either the ON state or the OFF state in the negative ion generation mode.

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

The bias circuit 35 is a circuit for applying a positive bias voltage to the film formation target 11 after film formation. The bias circuit 35 includes a bias power supply 27 for applying a positive bias voltage (hereinafter referred to as "bias voltage") to the film formation target 11, and a third wiring electrically connecting the bias power supply 27 and the trolley wire 18 73. And the short-circuit switch SW3 provided on the third wiring 73. The bias power supply 27 applies a rectangular wave voltage signal (periodical electrical signal) that periodically increases or decreases as a bias voltage. The bias power supply 27 is configured to be able to change the frequency of the applied bias voltage under the control of the control unit 50. One end of the third wiring 73 is connected to the positive potential side of the bias power supply 27 and the other end is connected to the trolley wire 18. Thereby, the third wiring 73 electrically connects the trolley wire 18 and the bias power source 27.

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

On the other hand, the short-circuit switch SW3 is in the OFF state at a predetermined timing in the film formation processing mode and in the negative ion generation mode. If the short-circuit switch SW3 is in the OFF state, the trolley wire 18 and the bias power supply 27 are electrically disconnected from each other, and no bias voltage is applied to the trolley wire 18. In addition, the details of the timing of applying the bias voltage will be described later.

The trolley wire 18 is an overhead wire for supplying power to the film-forming object holding member 16. The trolley wire 18 is extended in the conveyance direction (arrow B) and is provided in the conveyance room 10a. The trolley wire 18 is in contact with the power supply brush 42 provided on the film formation target holding member 16 to supply power to the film formation target holding member 16 through the power supply brush 42. The trolley wire 18 is composed of, for example, a metal wire made of stainless steel.

The potential measuring unit 110 measures the potential in the vacuum chamber 10. The potential measuring unit 110 measures the potential of the space around the film formation target 11. The potential measurement unit 110 includes a potential detection 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 the value of the floating potential at the position where the electrode portion 112 is provided based on the potential of the electrode portion 112. The potential detection unit 111 sends the detected value to the control unit 50 as a measured value.

The electrode portion 112 is a member that enters the internal space from the outside of the vacuum chamber 10. The electrode portion 112 is arranged at a position where the film formation object holding member 16 does not interfere with the movement. The tip portion 112 a of the electrode portion 112 is arranged in a space around the film formation target 11. The tip portion 112 a of the electrode portion 112 is arranged in the transfer chamber 10 a of the vacuum chamber 10. In addition, the front end portion 11a is arranged in the vicinity of the communication portion between the transfer chamber 10a and the film formation chamber 10b and at a position substantially the same as the film formation target 11 in the Z axis direction.

In addition, in the electrode portion 112, portions other than the tip portion 112a may be covered with an insulating member. For example, as shown in FIG. 6, in the electrode portion 112, an area inside the wall portion of the vacuum chamber 10 may be covered with an insulating member 140. In addition, only the front end 112a can be exposed from the insulating member 140 in the space of the vacuum chamber 10. At this time, detection of the floating potential is not performed except for the tip portion 112a, so the potential at a desired position can be concentratedly measured.

The control unit 50 is a device that controls the entire film forming and anion generating device 1, and is composed of a CPU, RAM, ROM, input and output interfaces, and the like. The control unit 50 is arranged outside the vacuum chamber 10. In addition, the control unit 50 includes: a mode switching unit 51 for switching between 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 90 for controlling the voltage The applied voltage control unit 53.

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 into the film formation chamber 10b. Next, the plasma control unit 52 of the control unit 50 controls the plasma gun 7 to intermittently generate plasma P from the plasma gun 7 in the film formation chamber 10b. For example, the control unit 50 switches the ON/OFF state of the short-circuit switch SW1 at predetermined intervals, thereby intermittently generating plasma P from the plasma gun 7 in the film formation chamber 10b.

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 drops sharply. Therefore, the electrons of the plasma P easily adhere to the particles of the oxygen supplied into the film forming chamber 10b in the aforementioned source gas supply process S21. Thereby, negative ions are efficiently generated in the film forming chamber 10b.

After stopping the generation of plasma P by the plasma gun 7, 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. The control unit 50 starts the application of the voltage by the voltage application unit 90 at a predetermined timing based on the measurement result of the potential measurement unit 110. In addition, the timing of starting the application of the voltage by the voltage applying unit 90 is preset by the control unit 50.

Here, the relationship between the generation of plasma P and the generation of negative ions will be described with reference to FIGS. 4 and 5. The solid line in FIG. 4(a) represents a curve of the floating potential at a predetermined position in the space of the vacuum chamber 10 when negative ions are generated. If the electrons or negative ions in the vacuum chamber 10 increase, the floating potential increases, and if the electrons or negative ions in the vacuum chamber 10 decrease, the floating potential decreases. FIG. 4(b) shows the number of negative ions per unit square area at a predetermined position in the space of the vacuum chamber 10. Fig. 5 is a graph showing the state of the floating potential immediately after the plasma generation is stopped. In Fig. 4, the generation of plasma P starts when the time is "0", and the generation of plasma P is stopped when the time is "t1". In addition, as shown in FIG. 4(a), at the moment the plasma P is stopped, the floating potential rises sharply. As shown in FIG. 4(b), after the plasma P is stopped, the amount of negative ions decreases rapidly, and then increases greatly at time t3, and reaches a rising peak at time t2. At a time corresponding to time t3 in Fig. 4(a), the floating potential reaches a rising peak value and then falls.

As shown in FIG. 5, after the plasma P stops, the floating potential rises rapidly in the interval E1, and slowly rises in the interval E2. After the floating potential reaches a rising peak around time t3, it falls in section E3. The floating potential after falling reaches the peak of the fall near time t2, and then, after the interval E4, the floating potential gradually rises. The interval E3 is also the interval in which the amount of negative ions increases sharply (see Figure 4(b)). Also, in section E3, when the amount of negative ions increases, the floating potential decreases, so it is considered to be a section in which the amount of electrons decreases.

From time t1 to time t3, the vacuum chamber 10 remains Ar plasma (Ar ^+, e ^-). It can be said that this is because even if the short-circuit switch SW1 is short-circuited, the voltage between the main hearth 17 and the second intermediate electrode 62 is still positive. For example, with Ar ^{+ +} e ^- → Ar disappeared, e flows into the vacuum chamber 10 and the potential measuring section 110 ^- is reduced. On the other hand, if it is the case of the electron temperature decreases (as O ₂ * O ₂ active state) is ^{_{performed: O 2 * + e - →}} O - + O ( detachability electron attachment) O + e ^- → O ^- (Electron adhesion) and other reactions produce O ^- which is slower than electrons. e ^- and O ^- compared to fast flowing into the vacuum chamber 10, the O ^- slow, the diffusion speed of gas temperature. Since there is a potential difference between the main hearth 17 and the second intermediate electrode 62 until time t3, e ^- and O ^- are drawn to the plasma P side in the vacuum chamber 10. After time t3, the traction force disappears, so e ^- and O ^- diffusion. The speed of e ^- and O ^- is very different, so the slow O ^- remains, and the O ^- is negatively charged. O ^- generating and ^{Ar + + e - → Ar,} O + + e - → O, O 2 + + e - → O 2 or the like ee ^- disappear simultaneously, so that the floating potential 4 as shown in FIG. Trace. If the balance between the generation and disappearance of plasma is considered, and the conflict of e ^- is considered, only O ^- and O ₂ ^- survive under negative charges. O ^- 90% or more, and thus become substantially O ^-. Therefore, even if the plasma P is OFF, that is, the electron supply disappears, the negatively charged one becomes O ⁻ from the above situation.

The control unit 50 starts the application of the voltage by the voltage application unit 90 at the timing when the potential rises and then falls based on the measurement result of the potential measurement unit 110. In the example shown in FIG. 5, the intervals where the potential rises are the interval E1 and the interval E2. The interval in which the potential drops is interval 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 timing in the interval E3 (including the time t3 at which the peak value becomes the falling peak). The voltage control unit 53 of the control unit 50 may start the application of the voltage based on the voltage application unit 90 in the area on the half side after the generation of negative ions has progressed to a certain extent in the section E3. In addition, the voltage control unit 53 of the control unit 50 may start the voltage application at the timing when the potential reaches the predetermined threshold in the interval E3.

In addition, the control unit 50 may start the application of the voltage by the voltage application unit 90 at the timing when the potential drops and reaches the peak of the drop based on the measurement result of the potential measurement unit 110. That is, the voltage control unit 53 of the control unit 50 starts the application of the voltage based on the voltage application unit 90 at the timing when the peak value P1 of the drop of the floating potential is reached. The control unit 50 monitors the amount of change in the potential based on the measurement result from the potential measurement unit 110, thereby grasping the peak value P1 at which the potential has fallen. In addition, the timing of starting the voltage application does not need to be exactly the same as the timing when the potential measured by the potential measurement unit 110 reaches the peak value P1, and may be a timing shifted from before and after the timing when the potential value P1 is reached.

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

Next, referring to the flowchart shown in FIG. 3, a part of the control content during the generation of negative ions by the control unit 50 will be described. In addition, 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 the generation of the plasma P by the plasma gun 7 (step S10). After the predetermined time has elapsed, 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 obtains the measurement result from the potential measurement unit 110 (step S30). Next, the voltage control unit 53 of the control unit 50 determines whether it is the timing to start the application of the voltage by the voltage application unit 90 based on the potential obtained in S30 (step S40).

In S40, when it is determined that it is not the timing of voltage application, the process is repeated from S30 again. On the other hand, in S40, when it is determined that it is the timing of voltage application, the voltage control unit 53 of the control unit 50 starts the application of the voltage. Thereby, by applying a positive bias voltage to the film formation target 11, the negative ions in the vacuum chamber 10 are guided to the film formation target 11.

In FIG. 3, the processing in the primary negative ion generation in the negative ion generation mode, that is, the generation of the plasma P by the plasma gun 7 and the primary stop of the generation of the plasma P are described. The film-forming and anion generating device 1 generates anions multiple times. That is, the control unit 50 repeatedly performs the generation of the plasma P by the plasma gun 7 and the generation of negative ions by stopping the generation of the plasma P. Therefore, referring to FIG. 7, the control content of the control unit 50 when negative ions are repeatedly generated will be described. At this time, in each generation of negative ions, the potential 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.

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

The function and effect of the film forming and anion generating device 1 of this embodiment will be described.

In the film forming and anion generating apparatus 1, the plasma gun 7 generates plasma P in the vacuum chamber 10, thereby being able to generate negative ions in the vacuum chamber 10. In addition, the voltage applying unit 90 applies a positive voltage to the film formation target 11, and the negative ions in the vacuum chamber 10 are guided to the film formation target 11 side, and the negative ions are irradiated to the film formation target 11. Here, after the generation of the plasma P by the plasma gun 7 is stopped, electrons are easily attached to the raw material of the negative ions, thereby generating the negative ions. Therefore, negative ions and electrons increase or decrease in the vacuum chamber 10, and therefore the potential inside the vacuum chamber 10 fluctuates. Therefore, it is possible to grasp the appropriate timing of irradiating the negative ions to the film-forming object 11 by the measurement result of the potential measuring unit 110 that measures the potential in the vacuum chamber 10. Therefore, 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 after stopping the generation of the plasma P by the plasma gun 7. Thereby, the control unit 50 can irradiate the film-forming object 11 with negative ions at a timing that can prevent the object from being irradiated with a large amount of electrons. With the above, it is possible to irradiate negative ions to the film formation target 11 at an appropriate timing.

The control unit 50 may start the application of the voltage based on the voltage application unit 90 at the timing of the potential rise and then the fall according to the measurement result of the potential measurement unit 110. The timing of the potential rise and then the fall is the timing that the generation of negative ions proceeds to a certain extent after the generation of the plasma P is stopped. Therefore, by starting the application of the voltage at this timing, the control unit 50 can irradiate the film formation target 11 with negative ions at the timing when the negative ions are generated.

The control unit 50 may start the application of the voltage by the voltage application unit 90 at the timing when the potential drops and reaches the peak of the drop based on the measurement result of the potential measurement unit 110. The timing of reaching the peak of the potential drop is close to the timing of the amount of generated negative ions becoming the peak after the generation of the plasma P is stopped. Therefore, by starting the application of the voltage at this timing, the control unit can irradiate the film formation target 11 with negative ions at a timing when there are many negative ions.

The control unit 50 may start the application of the voltage by the voltage application unit 90 at the timing of the potential rise based on the measurement result of the potential measurement unit 110. At this time, compared to the case where the application is started at the timing of the drop after the potential rises, and the timing of the drop peak after the potential falls, it is possible to irradiate more negative ions to the object. However, compared with the time when the potential rises and then drops, and the potential drops after the peak reaches the peak of the time when the application is started, there is a possibility that a large amount of electrons may be mixed. Therefore, it is possible to allow electrons to be irradiated. good.

The potential measuring unit 110 can measure the potential of the space around the film formation target 11. At this time, it can be controlled based on the situation in the vicinity of the film formation target 11 which is the irradiation target of the negative ions.

The control unit 50 repeatedly generates the plasma P of the plasma gun 7 and the generation of negative ions by stopping the generation of the plasma P. The potential measuring unit 110 measures the potential for each generation of negative ions. In addition, 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. If the voltage is applied by the voltage applying 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, there may be a change in the timing of the generation of negative ions after the generation of plasma P is stopped. For example, there are cases where electrons decrease in the second time compared to the first time. After the voltage application timing is determined based on the measurement result of the potential measurement unit 110 during the first negative ion generation, when the voltage is applied during the second and subsequent negative ion generation at the same timing, negative ion irradiation may not be performed at the appropriate timing. (However, this kind of control method is not excluded from the scope of item 1 of the scope of patent application). Therefore, as shown in FIG. 7, in each generation of negative ions, it is possible to irradiate the object with negative ions at an appropriate timing by performing measurement by the potential measurement unit 110 and control of voltage application based on the measurement result.

Here, when the voltage value of the voltage application is changed during the negative ion irradiation, the state of the plasma P changes, and when the voltage value is high, electrons increase. In each generation of negative ions, when the potential measurement unit 110 measures the potential, it is possible to reflect the influence of changing the applied voltage value of this kind of voltage into the control. In this way, it can be adapted to the situation where the negative ion irradiation amount and incident energy are changed in the program.

As mentioned above, an embodiment of the present embodiment has been described, but the present invention is not limited to the above-mentioned embodiment, and can be modified or applied to other embodiments within the scope not changing the spirit described in the scope of each patent application.

Furthermore, in the above-mentioned embodiment, since the ion plating type film forming device and the negative ion generating device are combined, the plasma P injected from the plasma gun is guided to the main hearth side. However, the negative ion generating device may not be combined with the film forming device. Therefore, the plasma P can be guided to, for example, the electrode on the wall opposite to the plasma gun.

For example, in the above-mentioned embodiment, the plasma gun 7 is a pressure gradient type plasma gun, but as long as it can generate plasma in the vacuum chamber 10, the plasma gun 7 is not limited to a pressure gradient type plasma gun. .

In addition, in the above-described embodiment, only one set of the plasma gun 7 and the hearth mechanism 2 is provided in the vacuum chamber 10, but multiple sets may be provided. In addition, the plasma P can 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 designing the orientation of the plasma gun 7 and the position or orientation of the material in the hearth mechanism 2.

1: Film formation and anion generator (anion generator) 7: Plasma gun 10: Vacuum chamber 11: Film-forming object 50: Control Department 90: Voltage application part 110: Potential measurement department P: Plasma

[Fig. 1] is a schematic cross-sectional view showing the structure of a film forming and anion generating device according to an embodiment of the present invention, and is a diagram showing the operating state in the film forming processing mode. [Fig. 2] is a schematic cross-sectional view showing the configuration of the film forming and anion generating device of Fig. 1, and is a diagram showing the operating state in the anion generating mode. [Fig. 3] is a flowchart showing the control contents of the control unit in the film forming/anion generating apparatus according to the embodiment of the present invention. [Fig. 4] Fig. 4(a) is a graph showing the floating potential at a predetermined position in the vacuum chamber space when negative ions are generated, and Fig. 4(b) is a graph showing the negative ions at a predetermined position in the vacuum chamber space The quantity per unit square area. [Fig. 5] is a graph showing the state of the floating potential immediately after the plasma generation is stopped. Fig. 6 is a diagram showing a modification example of the electrode part of the potential measuring part. [Fig. 7] is a flowchart showing the control content of the control unit in the film forming and anion generating apparatus according to the embodiment of the present invention.

2: Hearth mechanism

3: handling mechanism

5: Steering coil

6: Ring hearth

7(24): Plasma gun

9: Coil

10: Vacuum chamber

10a: transfer room

10b: Film forming chamber

10c: Plasma port

10h (10W): side wall

10i (10W): side wall

10j(10W): bottom wall

11: Film-forming object

12: container

14: Film forming department

15: Transport roller

16: Film-forming object holding member

17: Main hearth

17a: Filling part

17b: Flange

17c: Through hole

18(90): trolley wire

20: Permanent magnet part

27: Bias power supply

34(24): Circuit Department

35(90): Bias circuit

40(24): Raw gas supply part

41: Gas supply port

42: power brush

50(24): Control Department

51: Mode switching section

52: Plasma Control Department

53: Voltage Control Department

60: cathode

61: 1st middle electrode (grid)

61a: Ring permanent magnet

62: 2nd middle electrode (grid)

62a: Electromagnet coil

71: first wiring

72: 2nd wiring

73: 3rd wiring

80: Variable power supply

90: Voltage application part

110: Potential measurement department

111: Potential detection section

112: Electrode

112a: Front end

B: Transport direction (arrow)

P: Plasma

Ma: Film-forming material

R1~R4: resistor

SW1, SW2, SW3: short circuit switch

Claims (6)

A negative ion generating device that uses plasma to generate negative ions to irradiate an object, with: A chamber, which contains the aforementioned object and generates the aforementioned negative ions inside; A plasma gun, which generates the aforementioned plasma in the aforementioned chamber; Potential measuring part, which measures the electric potential in the aforementioned chamber; A voltage applying part capable of applying a positive voltage to the aforementioned object; and The control unit, which controls the aforementioned negative ion generating device; After the control unit stops generating the plasma of the plasma gun, it controls the application of the voltage by the voltage application unit based on the measurement result of the potential measurement unit. Such as the negative ion generating device of claim 1, wherein The control unit starts the application of the voltage by the voltage application unit at a timing when the potential rises and then falls based on the measurement result of the potential measurement unit. Such as the negative ion generating device of claim 2, wherein The control unit starts the application of the voltage by the voltage application unit at the timing when the potential drops and reaches the peak of the drop based on the measurement result of the potential measurement unit. Such as the negative ion generating device of claim 1, wherein The control unit starts the application of the voltage by the voltage application unit at the timing of the increase of the potential based on the measurement result of the potential measurement unit. Such as the negative ion generating device of any one of claims 1 to 4, wherein: The potential measurement unit measures the potential of the space around the object. Such as the negative ion generating device of any one of claims 1 to 4, wherein: The control unit repeatedly performs: the generation of the plasma by the plasma gun, and the generation of the negative ions by stopping the generation of the plasma; Each time the negative ions are generated, the potential measurement unit measures the potential, and the control unit controls the application of the voltage by the voltage application unit based on the measurement result of the potential measurement unit.

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