TW202343508A - Negative ion generating device capable of properly irradiating negative ions on object - Google Patents

Abstract

The invention provides a negative ion generating device capable of irradiating negative ions on an object at an appropriate time. A negative ion generating device (1) includes a negative ion generating part (4) that generates negative ions by generating plasma (P) in a chamber (2). After the negative ion generating part (4) stops the plasma (P), a substrate (11) can be irradiated with negative ions. Accordingly, the negative ion generating device (1) further includes a detection unit (40) that detects disappearance of the plasma (P). After the negative ion generation device (1) can confirm the disappearance of the plasma (P) using the detection unit (40), the substrate (11) can be irradiated with negative ions. Accordingly, the substrate (11) can be irradiated with negative ions at an appropriate time.

Description

Negative ion generating device

The invention relates to a negative ion generating device.

Conventionally, as a negative ion generating device, the negative ion generating device described in Patent Document 1 is known. This negative ion generating device includes a gas supply part that supplies gas that becomes a raw material of negative ions into a chamber, and a negative ion generating part that generates negative ions by generating plasma in the chamber. The negative ion generating unit generates negative ions in the chamber using plasma and irradiates the negative ions onto the object. The negative ion generating device irradiates negative ions to the object when the plasma is turned off. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2019-163531

[Problem to be solved by the invention]

Here, the negative ion generating device as described above measures the potential in the chamber after the plasma stops, and determines the appropriate timing to irradiate the object with negative ions based on the measurement results. However, in order to assemble such a potential measurement probe, a mechanism for introducing a vacuum into the chamber and the like are required, and there is a problem that the detection becomes complicated. On the other hand, after a predetermined delay time has elapsed after the plasma is turned off, the object may be irradiated with negative ions. However, in such a negative ion generating device, even after the plasma is controlled to be turned off, the plasma may not disappear and may continue to be in a plasma-on state. In this case, if the object is irradiated with negative ions, the object or device may be damaged.

Therefore, an object of the present invention is to provide a negative ion generating device capable of irradiating negative ions to an object at an appropriate time. [Technical means to solve problems]

In order to solve the above problems, the negative ion generating device of the present invention is a negative ion generating device that generates negative ions and irradiates the target object. It includes: a chamber that generates negative ions inside; and a negative ion generating unit that generates plasma by generating plasma in the chamber. generate negative ions; and a detection part to detect the generation and disappearance of plasma.

The negative ion generating device of the present invention includes a negative ion generating part that generates negative ions by generating plasma in a chamber. Therefore, it is possible to irradiate the object with negative ions after the negative ion generating unit stops the plasma. Here, the negative ion generating device includes a detection unit that detects the generation and disappearance of plasma. Therefore, the negative ion generating device can irradiate negative ions to the object after confirming the disappearance of the plasma with the detection unit. Thereby, the object can be irradiated with negative ions at an appropriate time.

The detection unit may include a light detection element that detects the amount of light in the chamber. Plasma light will inevitably be generated when plasma is generated, and as the plasma disappears, its light will also decrease. Therefore, the detection unit can accurately detect the disappearance of plasma by monitoring the plasma light using the photodetection element.

The light detection element can be installed in the viewing port of the chamber. In this case, the photodetection element can detect the disappearance of the plasma from the outside of the chamber. Therefore, the light detection element can be easily assembled into the device.

The negative ion generating device can stop operating based on the detection result of the detection unit. In this case, if the disappearance of the plasma is not detected even though the plasma is controlled to be turned off, it is considered that there is an abnormality in the device, and the operation can be stopped. This allows maintenance and the like to be performed after the operation is stopped.

The detection unit can detect the voltage at a predetermined location in the negative ion generating device. In this case, the disappearance of plasma can be detected without adding a light detection element or the like.

The detection part can detect the pressure in the chamber. In this case, the disappearance of the plasma can be detected using an existing pressure gauge or the like without adding a light detection element or the like. [Effects of the invention]

According to the present invention, a negative ion generating device capable of irradiating negative ions to an object at an appropriate time can be provided.

Hereinafter, a negative ion generating device 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 elements are denoted by the same symbols, and repeated descriptions are omitted.

First, the structure of the negative ion generating device according to the embodiment of the present invention will be described with reference to FIG. 1 . FIG. 1 is a schematic cross-sectional view showing the structure of the negative ion generating device according to this embodiment. In addition, for convenience of explanation, an XYZ coordinate system is shown in FIG. 1 . The X-axis direction is the thickness direction of the substrate as the object. The Y-axis direction and the Z-axis direction are directions orthogonal to the X-axis direction and orthogonal to each other.

As shown in FIG. 1 , the negative ion generation device 1 of this embodiment includes a chamber 2 , an object placement unit 3 , a negative ion generation unit 4 , a gas supply unit 6 , a circuit unit 7 , a voltage application unit 8 and a control unit 50 .

The chamber 2 is a member for accommodating the substrate 11 (object) and performing negative ion irradiation processing. The chamber 2 is a member for generating negative ions inside. The chamber 2 is made of conductive material and is connected to ground potential.

The chamber 2 is provided with a pair of wall portions 2a and 2b facing each other in the X-axis direction, a pair of wall portions 2c and 2d facing each other in the Y-axis direction, and a pair of wall portions facing each other in the Z-axis direction. (not shown). In addition, the wall portion 2a is arranged on the negative side in the X-axis direction, and the wall portion 2b is arranged on the positive side. The wall portion 2c is arranged on the negative side in the Y-axis direction, and the wall portion 2d is arranged on the positive side.

The object placement unit 3 arranges the substrate 11 that is an object to be irradiated with negative ions. The object arrangement part 3 is provided on the wall part 2a of the chamber 2. The object placement unit 3 includes a placement member 12 and a connection member 13 . The placement member 12 and the connection member 13 are made of conductive material. The placement member 12 is a member for placing the substrate 11 on the placement surface 12a. The placement member 12 is attached to the wall portion 2 a and is arranged in the internal space of the chamber 2 . The placement surface 12a is a plane extending orthogonally to the X-axis direction. Thereby, the substrate 11 is placed on the mounting surface 12a orthogonally to the X-axis direction and parallel to the ZY plane. The connection member 13 is a member that electrically connects the mounting member 12 and the voltage application part 8 . The connecting member 13 penetrates the wall portion 2 a and extends outside the chamber 2 . The placement member 12 and the connection member 13 are insulated from the chamber 2 .

In this embodiment, an insulating material can be used as the substrate 11 to be irradiated with negative ions. Examples of the insulating substrate 11 include glass substrates, fine ceramics such as SiO ₂ , SiON, AIN, Al ₂ O ₃ , and Si ₃ N ₄ , phenolic resins, epoxy resins, and polyimide resins. Teflon (registered trademark), fluororesin and other resin substrates, polyimide, PET and other flexible substrate materials. Furthermore, as the substrate 11, a metal plate, a conductive substrate, a semiconductor, etc. can be used.

Next, the structure of the negative ion generating unit 4 will be described in detail. The negative ion generating part 4 generates plasma and electrons in the chamber 2, thereby generating negative ions, free radicals, and the like. The negative ion generating unit 4 has a plasma gun 14 and an anode 16 .

The plasma gun 14 is, for example, a pressure gradient type plasma gun, and its body part is disposed on the wall 2 c of the chamber 2 and is connected to the internal space of the chamber 2 . The plasma gun 14 has a gas supply part (not shown) that supplies a rare gas such as Ar or He to generate plasma. The plasma gun 14 generates plasma P in the chamber 2 . The plasma P generated in the plasma gun 14 is ejected from the plasma port into the inner space of the chamber 2 in the form of a beam. Thereby, plasma P is generated in the internal space of the chamber 2 .

The anode 16 is a mechanism that guides the plasma P from the plasma gun to a desired position. The anode 16 is a mechanism having an electromagnet for inducing plasma P. The anode 16 is provided on the wall portion 2d of the chamber and is disposed at a position facing the plasma gun 14 in the Y-axis direction. Thereby, the plasma P is emitted from the plasma gun 14 , spreads in the internal space of the chamber 2 while moving toward the positive side in the Y-axis direction, and is guided to the anode 16 while converging. In addition, the positional relationship between the plasma gun 14 and the anode 16 is not limited to the above, and any positional relationship can be adopted as long as negative ions can be generated.

The gas supply unit 6 is arranged outside the chamber 2 . The gas supply part 6 supplies gas into the chamber 2 through the gas supply port 26 formed in the wall part 2d. The gas supply port 26 is formed between the negative ion generating part 4 and the object placement part 3 . Here, the gas supply port 26 is formed at a position between the end of the wall portion 2 d on the negative side in the X-axis direction and the anode 16 . However, the position of the gas supply port 26 is not particularly limited. The gas supply unit 6 supplies gas that becomes a raw material of negative ions. As the gas, for example, O ² _, which is a raw material for negative ions such as O -, NH ₂ and NH ₄ , which are raw materials for negative ions of nitrides such as NH ^- , and C which is a raw material for negative ions such as C ^- or Si ^- , can be used. ₂ H ₆ , SiH ₄ etc. In addition, the gas also includes rare gases such as Ar.

The circuit unit 7 includes a variable power supply 30, a first wiring 31, a second wiring 32, resistors R1 to R3, and a switch SW1. The variable power supply 30 applies a negative voltage to the cathode 21 of the plasma gun 14 and a positive voltage to the anode 16 across the chamber 2 at ground potential. Thereby, the variable power supply 30 generates a potential difference between the cathode 21 and the anode 16 of the plasma gun 14 . The first wiring 31 electrically connects the cathode 21 of the plasma gun 14 and the negative potential side of the variable power supply 30 . The second wiring 32 electrically connects the anode 16 and the positive potential side of the variable power supply 30 . The resistor R1 is connected in series between the first intermediate electrode 22 and the variable power supply 30 . The resistor R2 is connected in series between the second intermediate electrode 23 and the variable power supply 30 . Resistor R3 is connected in series between chamber 2 and variable power supply 30 . The switch SW1 switches on/off state by receiving the command signal from the control unit 50 . Switch SW1 is connected in parallel with resistor R2. The switch SW1 is in a closed state when the plasma P is generated. On the other hand, the switch SW1 is turned on when the plasma P is stopped.

The voltage applying unit 8 applies a bias voltage to the substrate 11 . The voltage application unit 8 includes a power supply 36 for applying a bias voltage to the substrate 11 , a third wiring 37 for connecting the power supply 36 and the object placement unit 3 , and a switch SW2 provided on the third wiring 37 . Power supply 36 applies a positive voltage as a bias voltage. One end of the third wiring 37 is connected to the positive potential side of the power supply 36 , and the other end is connected to the connecting member 13 . Thereby, the third wiring 37 electrically connects the power source 36 and the substrate 11 via the connecting member 13 and the mounting member 12 . The switch SW2 is switched on/off by the control unit 50 . The switch SW2 is turned on at a predetermined time when negative ions are generated. When the switch SW2 is turned on, the connecting member 13 and the positive potential side of the power supply 36 are electrically connected to each other, and a bias voltage is applied to the connecting member 13 . On the other hand, the switch SW2 becomes closed at a predetermined time when negative ions are generated. When the switch SW2 is in the closed state, the connection member 13 and the power supply 36 are electrically disconnected from each other, and a bias voltage is not applied to the connection member 13, so that the connection member 13 becomes a floating state. In addition, a more detailed structure of the voltage application part 8 will be described later.

The control unit 50 is a device that controls the entire negative ion generating device 1 and includes an ECU [Electronic Control Unit] that centrally manages the entire device. ECU has CPU [Central Processing Unit: central processing unit], ROM [Read Only Memory: read-only memory], RAM [Random Access Memory: random access memory], CAN [Controller Area Network: controller area network ] Electronic control unit for communication circuits, etc. In the ECU, for example, a program stored in ROM is read into RAM, and the CPU executes the program read into RAM, thereby realizing various functions. ECU can also be composed of multiple electronic units.

The control unit 50 is arranged outside the chamber 2 . Furthermore, the control unit 50 includes: a gas supply control unit 51 that controls gas supply by the gas supply unit 6; a plasma control unit 52 that controls the generation of plasma P by the negative ion generation unit 4; and a voltage control unit 53 that controls the generation of plasma P by the negative ion generation unit 4. The voltage application unit 8 applies the bias voltage. The control unit 50 performs control so that the plasma P is generated and stopped intermittently.

When the switch SW1 is turned into a closed state under the control of the plasma control unit 52 , the plasma P from the plasma gun 14 is ejected into the chamber 2 , so that the plasma P is generated in the chamber 2 . Plasma P contains neutral particles, positive ions, negative ions (when negative gases such as oxygen are present), and electrons as constituent materials. When the switch SW1 is turned on under the control of the plasma control unit 52 , the plasma P from the plasma gun 14 is not ejected into the chamber 2 , so the electron temperature of the plasma P in the chamber 2 drops sharply. Therefore, electrons are easily attached to particles of the gas supplied into the chamber 2 . Thereby, negative ions are efficiently generated in the generation chamber 10b. The voltage control unit 53 controls the voltage application unit 8 to apply a forward bias voltage to the substrate 11 when the plasma P stops. Thereby, the negative ions in the chamber 2 are guided to the substrate 11 , and the negative ions are irradiated onto the substrate 11 .

FIG. 2 is a graph showing the ON/OFF timing of the plasma P and the flow of positive ions and negative ions toward the object. In the figure, the area marked "on" indicates the generation state of the plasma P, and the area marked "off" indicates the stopped state of the plasma P. At time t1, the plasma P stops. During the generation of plasma P, a large number of positive ions are generated. At this time, a large amount of electrons are also generated in the chamber 2 . Moreover, when the plasma P stops, the positive ions decrease sharply. At this time, the number of electrons also decreases. After the plasma P stops, the negative ions increase sharply from time t2 when a predetermined time has elapsed, and reach a peak value at time t3. In addition, the positive ions and electrons gradually decrease after the plasma P stops, and near time t3, the amount of positive ions becomes the same as the amount of negative ions, and the electrons almost disappear.

Here, as shown in FIG. 1 , the negative ion generating device 1 includes a detection unit 40 that detects the disappearance of plasma P. The detection unit 40 includes a photodetection element 41 and a plasma monitoring unit 54 of the control unit 50 .

The light detection element 41 is an element that detects the amount of light in the chamber 2 . The photodetector element 41 is preferably a photodiode with small delay, for example. However, if there is a delay in the circuit for amplifying the signal from the photodiode, a photodiode that is an optical element with a built-in amplifier may also be used. crystal. When a photodiode is used as the photodetection element 41, it is characterized in that the retardation with respect to light is small, but the intensity of the signal obtained is low. When a combination of a photodiode and an amplifier is used as the photodetection element 41 , the amplifier can be used to amplify the signal from the photodiode. When a photoelectric transistor is used as the light detection element 41, amplification and delay will occur, but it has the advantage of high signal intensity. Regarding the response speed, the photodiode alone is the fastest, while the "photodiode + amplifier" and phototransistor are approximately the same. Regarding the signal strength, the photodiode alone is the weakest, while the "photodiode + amplifier" and phototransistor are about the same level.

The light detection element 41 is installed in the viewing port 42 of the chamber 2 . The viewing port 42 is an observation window formed in the wall of the chamber 2 , and is a portion through which the internal state of the chamber 2 can be visually confirmed from the outside. The viewing port 42 has a light-transmitting member provided on the wall of the chamber 2 . The light detection element 41 is disposed outside the chamber 2 and detects the amount of light in the chamber 2 through the light-transmitting member of the viewing port 42 . The light detection element 41 sends the detected signal to the control part 50 .

The plasma monitoring unit 54 of the control unit 50 monitors the plasma P in the chamber 2 based on the signal detected by the light detection element 41 . When the amount of light detected by the photodetection element 41 is equal to or greater than a predetermined value, the plasma monitoring unit 54 detects that plasma P is generated in the chamber 2 . When the amount of light detected by the photodetector element 41 decreases and becomes less than a predetermined threshold value, the plasma monitoring unit 54 detects the disappearance of the plasma P in the chamber 2 .

For example, FIG. 3 shows the temporal change of the voltage V of the anode 16 and the temporal change of the detection signal from the photodetector element 41 , that is, the light amount PT. As shown in FIG. 3 , the plasma control unit 52 suddenly decreases the light amount PT at the time when the plasma P turns off. The plasma monitoring unit 54 detects the disappearance of the plasma P when the light amount PT becomes equal to or less than the predetermined threshold value TH. After the plasma control unit 52 performs control to stop the plasma P and the plasma monitoring unit 54 detects the disappearance of the plasma P, the voltage control unit 53 controls the voltage application unit 8 to apply a forward bias voltage to the substrate 11 . Thereby, in the chamber 2 after the plasma P disappears, the negative ions are guided to the substrate 11 , and the negative ions are irradiated onto the substrate 11 . For example, the voltage control unit 53 applies the bias voltage at a time when the plasma P is turned off and a large number of negative ions exist in the time region E1 (see FIG. 2 ) in the chamber.

Furthermore, the plasma monitoring unit 54 stops the negative ion generating device 1 based on the detection result of the detection unit 40 . For example, the plasma monitoring unit 54 stops the negative ion generating unit 4 when the disappearance of the plasma P cannot be detected after a predetermined time has elapsed since the plasma control unit 52 turned off the plasma P.

Next, the operation and effect of the negative ion generating device 1 of this embodiment will be described.

The negative ion generating device 1 of this embodiment includes a negative ion generating part 4 that generates negative ions by generating plasma P in the chamber 2 . Therefore, after the negative ion generating unit 4 stops the plasma P, the substrate 11 can be irradiated with negative ions. Here, the negative ion generating device 1 includes a detection unit 40 that detects the disappearance of the plasma P. Therefore, the negative ion generation device 1 can irradiate the substrate 11 with negative ions after confirming the disappearance of the plasma P with the detection unit 40 . Thereby, negative ion irradiation can be performed at an appropriate time. Thereby, the substrate 11 can be irradiated with negative ions at an appropriate time.

For example, if the voltage control unit 53 applies a bias voltage to the substrate 11 when the plasma P is not actually turned off, problems such as damage to the substrate 11 or device failure may occur. Referring to FIG. 4 , an example of a malfunction when a bias voltage is applied while the plasma P is in an on state will be described. FIG. 4(a) is a graph showing the time-dependent changes in the negative ion density and the like when a low bias voltage is applied, and FIG. 4(b) is a graph showing the time-dependent changes in the negative ion density and the like when a high bias voltage is applied. Here, it is assumed that the bias voltage is applied from the time point t0 when the plasma is turned off. Time t0 is determined by charge balance, and increases when there are more electrons. That is, residual electrons are temporarily accumulated at high bias compared to low bias, so the increase in negative ion flux is delayed accordingly. At the moment of low bias, if a high bias voltage is applied, there will be more electrons, so a large current will flow. The same thing happens with the discharge current. The time t0 on the high current side becomes longer, and the peak after the rise at low current (low bias) disappears and becomes a flat negative ion flux. As shown in Fig. 4(c), the CC mode is entered at Δt at high bias, and then the CV mode is entered.

When electrons accumulate too much or negative ion current flows too much for each bias, the bias power supply may enter CC mode instead of CV mode. It is assumed that if a bias voltage is applied when the plasma is turned on, the current limit on the power supply side will take effect and the system will shift to the CC mode. Therefore, the voltage application method may change further than what is shown in Figure 4. As a problem in this case, since the protection circuit functions and a constant voltage cannot be applied, the negative ion irradiation process becomes uneven. In addition, if too much current flows through the bias power supply and transitions to CC mode without applying voltage, the switcher outputting the bias power supply may be damaged even if the power supply withstands it to a certain extent.

On the other hand, the negative ion generation device 1 can apply the bias voltage after confirming the disappearance of the plasma P, and therefore can perform negative ion irradiation at an appropriate time without causing the above-mentioned problems. Thereby, the substrate 11 can be irradiated with negative ions at an appropriate time.

The detection unit 40 may include a light detection element 41 that detects the amount of light in the chamber 2 . Plasma light will inevitably be generated when plasma P is generated, and as the plasma P disappears, its light will also decrease. Therefore, the detection unit 40 can accurately detect the disappearance of the plasma P by monitoring the plasma light using the photodetection element 41 .

The light detection element 41 can be installed in the viewing port 42 of the chamber 2 . In this case, the photodetection element 41 can detect the disappearance of the plasma P from the outside of the chamber 2 . Therefore, the light detection element 41 can be easily assembled into the device. For example, with regard to the conventional negative ion generation device 1, as long as the photodetection element 41 is attached at the position of the view port 42 and a signal is input to the control part 50, the detection part 40 can be easily constructed by subsequent installation.

The negative ion generation device 1 can stop operating based on the detection result of the detection unit 40 . In this case, if the disappearance of the plasma P is not detected even though the plasma is controlled to be turned off, it is considered that there is an abnormality in the device, and the operation can be stopped. This allows maintenance and the like to be performed after the operation is stopped.

The present invention is not limited to the above-described embodiment.

For example, in the above-described embodiment, the photodetection element 41 is disposed in the viewport 42, but the position where the photodetection element 41 is disposed is not particularly limited. For example, the photodetection element 41 may be provided in the chamber 2 . Furthermore, the position of the viewing port 42 is not limited as long as the plasma light can be observed. The same applies to the position of the photodetector element 41 .

In the above-described embodiment, the detection unit 40 uses the photodetection element 41, but the photodetection element 41 may not be used. For example, the detection unit 40 may detect the voltage at a predetermined location in the negative ion generation device 1 . In this case, the disappearance of the plasma P can be detected without adding the light detection element 41 or the like. However, the detection unit 40 may use the photodetection element 41 and voltage-based detection in combination. In this case, the disappearance of the plasma P can be detected more accurately.

As shown in FIGS. 5(a) and 5(b) , the voltage at each part of the negative ion generating device 1 changes when the voltage changes from plasma on to plasma off. In addition, the negative ion generating device 1 shown in FIG. 1 does not have a main furnace and a ring furnace, but it may also have a main furnace that guides plasma while holding the material, and a ring furnace installed around the main furnace. cylinder.

The detection unit 40 can detect based on the voltage of the main furnace (anode). When the voltage of the main furnace drops from about +25V to +10V, for example, the threshold value may be set between these voltages (for example, +20V). The detection unit 40 can detect the plasma shut-off signal and detect the disappearance of the plasma P on the condition that the voltage value becomes below the threshold value.

The detection unit 40 can detect based on the voltage of the second intermediate electrode 23 . When the voltage of the second intermediate electrode 23 rises from about -5V to about +10V, for example, the threshold value may be set between these voltages (for example, 0V). The detection unit 40 can detect the plasma shut-off signal and detect the disappearance of the plasma P on the condition that the voltage value becomes above the threshold value.

The detection unit 40 can detect based on the voltage of the ring hearth. Although the voltage variation of the ring hearth is small, a negative peak appears when the plasma is turned off and a positive peak appears when the plasma is turned on. The detection unit 40 can detect based on this change.

The detection unit 40 can detect based on the voltage of the cathode 21 . The cathode 21 has a basically negative voltage, and the absolute value of the voltage when the plasma is off is smaller than when the plasma is on. Therefore, for example, the detection unit 40 can detect the disappearance of the plasma P under the condition that it is closer to 0V than -30V. .

Introduction/non-introduction of the plasma P is performed by short-circuiting the anode 16 and the cathode 21. Therefore, as shown in the graph (see A) of FIG. 6, the potential between the two electrodes during non-introduction is almost 0. Thereby, the detection part 40 can detect the disappearance of the plasma P at the time when the voltage is 0V.

The detection part 40 may detect based on the temperature of the wall of the chamber 2 which is heated when the plasma is turned on and cooled when the plasma is turned off.

Furthermore, the detection unit 40 can detect the pressure in the chamber 2 . In this case, the disappearance of the plasma P can be detected using an existing pressure gauge or the like without adding the light detection element 41 or the like. However, the detection unit 40 may use the photodetection element 41 and pressure-based detection in combination. In this case, the disappearance of the plasma P can be detected more accurately.

Chamber 2 is heated when the plasma is on, so the pressure rises, and falls when the plasma is off. The detection unit 40 may detect the pressure using, for example, a diaphragm pressure gauge with good responsiveness. Alternatively, generally, the ionization vacuum gauge may be installed through a wire mesh or connected via an elbow pipe or the like so that electrons and ions of the plasma P do not enter, but the pressure may be detected without taking these measures. The ionization vacuum gauge ionizes the residual gas and observes its current value. Therefore, if electrons or ions flow through it, it is judged that a large amount of residual gas has been ionized, causing the pressure to become a high value. Utilizing this property of the ionization vacuum gauge, the detection unit 40 can detect the disappearance of the plasma P.

For example, in the above embodiment, the plasma gun 14 is a pressure gradient type plasma gun. However, the plasma gun 14 only needs to be able to generate plasma in the chamber 2 and is not limited to a pressure gradient type plasma gun. gun.

Furthermore, in the above embodiment, only one set of the plasma guns 14 and the set of the anodes 16 for guiding the plasma P are provided in the chamber 2, but a plurality of sets may be provided. Furthermore, plasma P may be supplied to one site from a plurality of plasma guns 14 .

This application claims priority based on Japanese Patent Application No. 2022-060352 filed on March 31, 2022. The entire contents of this Japanese application are incorporated by reference into this specification.

1: Negative ion generating device 2: Chamber 4: Negative ion generation department 11:Substrate (object) 40:Testing Department 41:Light detection element 42:Viewport

[Fig. 1] A schematic cross-sectional view showing the structure of the negative ion generating device according to this embodiment. [Fig. 2] A graph showing the ON/OFF timing of the plasma P and the flow of positive ions and negative ions towards the object. [Fig. 3] shows the temporal change of the voltage V of the anode and the detection signal from the photodetector, that is, the temporal change of the light amount. [Fig. 4] A diagram illustrating a malfunction when a bias voltage is applied while the plasma is in an on state. [Fig. 5] A graph showing temporal changes in voltage at each location. [Fig. 6] A graph showing changes over time in the voltage between the anode and the cathode.

1: Negative ion generating device

2: Chamber

2a, 2b, 2c, 2d: wall

3:Object placement department

4: Negative ion generation department

6:Gas supply department

7:Circuit Department

8: Voltage application part

11:Substrate

12: Place components

13:Connection components

14: Plasma gun

16:Anode

21:Cathode

22: 1st middle electrode

23: 2nd intermediate electrode

26:Gas supply port

30:Variable power supply

31: 1st wiring

32: 2nd wiring

36:Power supply

37: 3rd wiring

40:Testing Department

41:Light detection element

42:Viewport

50:Control Department

51:Gas supply control department

52:Plasma Control Department

53: Voltage control department

54:Plasma Monitoring Department

P:plasma

R1, R2, R3: resistors

SW1, SW2: switch

X, Y, Z: axis direction

Claims (6)

A negative ion generating device that generates negative ions and irradiates them to a target object. The negative ion generating device is provided with: Chamber, in which the aforementioned negative ions are generated; a negative ion generating unit that generates the negative ions by generating plasma in the chamber; and The detection part detects the disappearance of the aforementioned plasma. The negative ion generating device as described in claim 1, wherein The detection unit has a light detection element that detects the amount of light in the chamber. The negative ion generating device as described in claim 2, wherein The aforementioned light detection element is installed in the viewing port of the aforementioned chamber. The negative ion generating device according to any one of claims 1 to 3, wherein The operation is stopped based on the detection result of the detection unit. The negative ion generating device according to any one of claims 1 to 3, wherein The detection unit detects the voltage at a predetermined location in the negative ion generating device. The negative ion generating device according to any one of claims 1 to 3, wherein The detection unit detects the pressure in the chamber.

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