TW202137282A - Negative ion generator has an ultraviolet light suppression mechanism that suppresses the ultraviolet light directed to the object - Google Patents

Abstract

The present invention provides a negative ion generator capable of suppressing damage to an object. The negative ion generator (1) has: an ultraviolet light suppression mechanism (60) that suppresses the ultraviolet light (UV) directed to the object allocation part (3) between the negative ion generating part (4) and the object allocation part (3). When the negative ion generating part (4) generates plasma (P) to generate negative ions, the plasma light containing ultraviolet light (UV) is directed in the direction of the substrate (11) arranged on the object allocation part (3). At this time, the ultraviolet light (UV) directed to the substrate (11) is suppressed by the ultraviolet light suppression mechanism (60), so that the ultraviolet light (UV) irradiated on the substrate (11) can be reduced or blocked.

Description

Negative ion generator

The present invention relates to a negative ion generating device. This application claims priority based on Japanese Patent Application No. 2020-049133 filed on March 19, 2020. The entire content of this Japanese application is incorporated in this specification by reference.

Conventionally, as an anion generator, the anion generator described in Patent Document 1 is known. The negative ion generator includes a gas supply part that supplies gas that becomes a raw material of negative ions into the chamber; and an negative ion generator that generates negative ions by generating plasma in the chamber. The negative ion generating unit generates negative ions in the chamber by plasma, thereby irradiating the negative ions to the object. [Prior Technical Literature]

[Patent Document 1] JP 2017-025407 A

Here, in the negative ion generator as described above, when plasma is generated by the negative ion generator, the plasma light includes ultraviolet light. At this time, there is a possibility that the ultraviolet light is irradiated to the object that is irradiated with negative ions, which may damage the object.

[The problem to be solved by the invention]

Therefore, the object of the present invention is to provide a negative ion generator capable of suppressing damage to an object. [Technical means to solve the problem]

In order to solve the above-mentioned problems, the negative ion generator of the present invention is a negative ion generator that generates negative ions and irradiates them to an object. The negative ion generator includes: a chamber for generating negative ions inside; Plasma is generated to generate negative ions; the object arranging part is the arranging object; and the ultraviolet light suppression mechanism is arranged between the negative ion generating part and the object arranging part to suppress ultraviolet light toward the object arranging part.

The negative ion generating device of the present invention is provided with an ultraviolet light suppression mechanism that suppresses ultraviolet light directed to the object arranging portion between the anion generating portion and the object arranging portion. When the negative ion generating part generates plasma in order to generate negative ions, the plasma light containing ultraviolet light is directed in the direction of the object arranged in the object arrangement part. At this time, the ultraviolet light suppression mechanism suppresses the ultraviolet light directed to the object, thereby being able to reduce or block the ultraviolet light irradiated to the object. In summary, damage to the object can be suppressed.

The ultraviolet light suppression mechanism may have a member arranged between the ion generating part and the object arrangement part in the chamber and for suppressing the passage of ultraviolet light. At this time, even if the shape of the entire chamber is not changed, only by adding a member to the existing chamber, it is possible to suppress ultraviolet light directed to the object.

The member can inhibit the passage of ultraviolet light and allow the passage of negative ions. At this time, even if a mechanism or the like for moving the member is not provided, it is possible to suppress ultraviolet light directed to the object.

The ultraviolet light suppression mechanism may have a switching part that switches the position of the member at the time when plasma is generated by the negative ion generating part and when the plasma is stopped. At this time, when the plasma is generated, the switching section arranges the member between the negative ion generating section and the object, and can block the ultraviolet light directed to the object. On the other hand, when the plasma is stopped, the switching part removes the member, whereby the negative ions generated by the negative ion generating part can be irradiated to the object.

The ultraviolet light suppression mechanism may be constituted by a chamber in which ultraviolet light is blocked by a wall between the negative ion generating part and the object arrangement part. In this case, it is possible to suppress ultraviolet light directed to the object without adding another member. [Effects of Invention]

According to the present invention, it is possible to provide a negative ion generating device capable of suppressing damage to an object.

Hereinafter, referring to the drawings, a negative ion generator according to an embodiment of the present invention will be described. 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, the structure of the negative ion generator according to the embodiment of the present invention will be described. Fig. 1 is a schematic cross-sectional view showing the structure of the negative ion generator of this embodiment. In addition, for convenience of description, the 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 generator 1 of the present embodiment includes a chamber 2, an object arrangement part 3, an negative ion generator 4, a gas supply part 6, a circuit part 7, a voltage application part 8, and a control part 50.

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

The chamber 2 includes a pair of wall portions 2a, 2b facing in the X-axis direction, a pair of wall portions 2c, 2d facing in the Y-axis direction, and a pair of wall portions facing 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 arranging part 3 is for arranging a substrate 11 to be an irradiation object of negative ions. The object arrangement portion 3 is provided on the wall portion 2a of the chamber 2. The object arrangement portion 3 includes a mounting member 12 and a connecting member 13. The mounting member 12 and the connecting member 13 are made of conductive materials. The mounting member 12 is a member for mounting the substrate 11 on the mounting surface 12a. The mounting member 12 is mounted on the wall portion 2 a and is arranged in the internal space of the chamber 2. The placement surface 12a is a flat surface that is developed so as to be orthogonal to the X-axis direction. Thereby, the substrate 11 is placed on the placement surface 12a so as to be orthogonal to the X-axis direction and parallel to the ZY plane. The connecting member 13 is a member that electrically connects the placing member 12 and the voltage applying part 8. The connecting member 13 penetrates the wall portion 2 a and extends to the outside of the chamber 2. In addition, the positional relationship of the connecting member 13 may adopt any positional relationship as long as it does not interfere with the positions of the plasma gun 14 and the anode 16 as the negative ion generating portion 4.

As the substrate 11 to be an object of negative ion irradiation, for example, a substrate in which a _{film of ITO, IWO, ZnO, Ga 2} O ₃ , AlN, GaN, SiON, or the like is formed on the surface of the substrate is used. As the base material, for example, a plate-shaped member such as a glass substrate or a plastic substrate is used.

Next, the structure of the negative ion generation part 4 is demonstrated in detail. The negative ion generator 4 generates plasma and electrons in the chamber 2, thereby generating negative ions, free radicals, and the like. The negative ion generator 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 is provided on the wall 2c of the chamber 2 and connected to the inner space of the chamber 2. The plasma gun 14 generates plasma P in the chamber 2. The plasma P generated in the plasma gun 14 is emitted in a beam shape from the plasma port to the inner space of the chamber 2. 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 or magnet for inducing the plasma P. The anode 16 is provided on the wall portion 2d of the chamber, and is arranged at a position facing the plasma gun 14 in the Y-axis direction. Thereby, the plasma P is ejected from the plasma gun 14, spreads in the internal space of the chamber 2 toward the positive side in the Y-axis direction, and then converges and is guided to the anode 16. In addition, the positional relationship between the plasma gun 14 and the anode 16 is not limited to the above, and any positional relationship may be adopted as long as negative ions can be generated.

The gas supply part 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 arrangement part 3. Here, the gas supply port 26 is formed at a position between the end of the wall portion 2d 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 part 6 supplies a gas which becomes a raw material of negative ions. As the gas, for example, be employed O ^- O ₂ ions and the like raw materials, become NH ^- NH nitride raw materials and other negative ions _2, NH _4, except be C ^- C of raw materials and other negative ₂ ^- or Si H ₆ , SiH ₄ and so on. In other words, it can be said that raw materials with positive electron affinity are used. In addition, the gas also contains rare gases such as Ar as a carrier gas to stabilize the discharge.

The circuit section 7 has a variable power supply 30, a first wiring 31, a second wiring 32, resistors R1 to R3, and a switch SW1. The variable power source 30 applies a negative voltage to the cathode 21 of the plasma gun 14 and a positive voltage to the anode 16 through the chamber 2 at the ground potential. Thereby, the variable power source 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 source 30. The second wiring 32 electrically connects the anode 16 and the positive potential side of the variable power source 30. The resistor R1 is connected in series between the first intermediate electrode 22 and the variable power source 30. The resistor R2 is connected in series between the second intermediate electrode 23 and the variable power source 30. The resistor R3 is connected in series between the chamber 2 and the variable power source 30. The switch SW1 receives a command signal from the control unit 50 to switch the ON/OFF state. The switch SW1 is connected in parallel with the resistor R2. The switch SW1 is turned off when the plasma P is generated. On the other hand, the switch SW1 becomes the ON state when the plasma P is stopped.

The voltage applying unit 8 applies a bias voltage to the substrate 11. The voltage applying unit 8 includes a power source 36 that applies a bias voltage to the substrate 11; a third wiring 37 that connects the power source 36 and the object placement portion 3; and a switch SW2 that is provided on the third wiring 37. The 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 source 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 through the connection 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 point when negative ions are generated. When the switch SW2 is in the ON state, the connection member 13 and the positive potential side of the power source 36 are electrically connected to each other, and a bias voltage is applied to the connection member 13. On the other hand, the switch SW2 is turned off at a predetermined point when negative ions are generated. When the switch SW2 is in the OFF state, the connecting member 13 and the power supply 36 are electrically disconnected from each other, the bias voltage is not applied to the connecting member 13, and the connecting member 13 becomes a floating state. When the connecting member 13 is in a floating state, for example, the positive and negative balance of particles flowing into the substrate 11 when the plasma is ON becomes a minimum.

The control unit 50 is a device that controls the entire negative ion generator 1 and is provided with an ECU [Electronic Control Unit] that 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 of communication circuit, etc. In the ECU, for example, the program stored in the ROM is loaded into the RAM, and the CPU executes the program loaded into the RAM, thereby realizing various functions. The ECU can also be composed of a plurality of electronic units.

The control unit 50 is arranged outside the chamber 2. In addition, the control unit 50 includes: a gas supply control unit 51 that controls the gas supply based on the gas supply unit 6; a plasma control unit 52 that controls the generation of plasma P based on the negative ion generation unit 4; and a voltage control unit 53 that controls The voltage applying section 8 applies a bias voltage. The control unit 50 controls to perform an intermittent operation that repeats the generation and stop of the plasma P.

When the switch SW1 is turned off by the control of the plasma control unit 52, the plasma P from the plasma gun 14 is ejected into the chamber 2 and therefore the plasma P is generated in the chamber 2. Plasma P uses neutral particles, positive ions, negative ions (in the presence of negatively charged gas such as oxygen), and electrons as constituent materials. When the switch SW1 is turned on by 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 easily adhere to the particles supplied to the gas in 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 on the substrate 11.

FIG. 2 is a graph showing the timing of the ON/OFF of the plasma P and the flight status of positive ions and negative ions to an object. In the figure, the area described as "ON" indicates the generation state of the plasma P, and the area described as "OFF" indicates the stop state of the plasma P. At time t1, the plasma P stops. In the generation of plasma P, a large amount 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 are sharply reduced. At this time, electrons are also reduced. After the plasma P stops, the negative ions increase sharply from time t2 after a predetermined time has elapsed, and peak at time t3. In addition, the positive ions and electrons decrease after the plasma P stops, and the amount of positive ions is the same as the amount of negative ions around time t3, and the electrons almost disappear.

Here, the negative ion generator 1 further includes an ultraviolet light suppression mechanism 60. The ultraviolet light suppression mechanism 60 is a mechanism that suppresses the ultraviolet light UV toward the object placement section 3, that is, the ultraviolet light UV toward the substrate 11, between the negative ion generation section 4 and the object placement section 3. In this embodiment, the ultraviolet light suppression mechanism 60 has aperture ratio adjusting members 61A, 61B ( member). The aperture ratio adjusting members 61A and 61B suppress the passage of ultraviolet light UV and allow the passage of the supply PM such as negative ions and radicals (atoms and molecules with unpaired electrons). In addition, in the present embodiment, the ultraviolet light UV from the plasma P and the supply PM mainly travel from the positive side to the negative side in the X-axis direction, and are irradiated on the substrate 11. Therefore, the X-axis direction is sometimes referred to as the “irradiation direction”. In addition, the positive side in the X-axis direction may be referred to as the "upstream side in the irradiation direction", and the negative side in the X-axis direction may be referred to as the "downstream side in the irradiation direction".

The aperture ratio adjusting members 61A and 61B are plate-shaped members having through portions, respectively. The aperture ratio adjusting members 61A and 61B are arranged so as to be orthogonal to the irradiation direction, that is, so as to expand parallel to the YZ plane. In addition, the aperture ratio adjusting members 61A and 61B are arranged so as to face each other in the irradiation direction. Here, the aperture ratio adjustment member 61A is arranged on the upstream side in the irradiation direction, and the aperture ratio adjustment member 61B is arranged on the downstream side in the irradiation direction. In addition, the aperture ratio adjusting members 61A and 61B can be arranged such that the penetration portions of each other are shifted when viewed from the irradiation direction, thereby adjusting the aperture ratio in advance.

Referring to FIG. 3, an example of the aperture ratio adjusting members 61A and 61B will be described. Fig. 3 (a) is a schematic view of a case where the aperture ratio adjusting member 61A and the aperture ratio adjusting member 61B overlap from the upstream side in the irradiation direction. Fig. 3(b) is a schematic view in which the aperture ratio adjusting member 61A is removed, and only the aperture ratio adjusting member 61B is viewed from the upstream side in the irradiation direction. As shown in FIG. 3(a), the aperture ratio adjusting member 61A has circular through portions 62A distributed in a predetermined pattern. Furthermore, as shown in FIG. 3(b), the aperture ratio adjusting member 61B has circular through portions 62B distributed in a predetermined pattern. When viewed from the irradiation direction, the penetration portion 62A and the penetration portion 62B are arranged to be shifted from each other. Therefore, the penetration portion 62A of the aperture ratio adjustment member 61A is in a state of being blocked by the plate portion (a portion other than the penetration portion 62B) of the aperture ratio adjustment member 61B.

As described above, the aperture ratio adjusting members 61A and 61B have a structure in which there are no opening portions when viewed from the irradiation direction. Therefore, when the ultraviolet light UV emitted from the plasma P travels in the irradiation direction, it is blocked by the combination of the aperture ratio adjusting members 61A and 61B. On the other hand, the aperture ratio adjusting members 61A and 61B are separated from each other with a small gap in the irradiation direction. Therefore, the space SP1 (see FIG. 1) closer to the plasma P side than the aperture ratio adjusting members 61A and 61B and the space SP2 (see FIG. 1) closer to the substrate 11 than the aperture ratio adjusting members 61A and 61B pass through the penetration portion 62A , The gap and the through portion 62B are spatially connected. Therefore, the supply PM from the space SP1 can enter the space SP2 by repeating reflection between members and the like. This allows the supply PM, especially negative ions, to pass through the aperture ratio adjusting members 61A and 61B and irradiate the substrate 11. In addition, the ultraviolet light UV also has a component that is inclined with respect to the irradiation direction or a component that is reflected between members, so that a part of it enters the space SP2. However, the amount of ultraviolet light UV that enters is quite small compared to the supply PM.

In FIGS. 3(a) and (b), when viewed from the irradiation direction, the combined structure of the aperture ratio adjusting members 61A, 61B does not have an opening. However, in order to increase the throughput of the supply PM, an opening may be formed. Specifically, as shown in FIG. 3(b), the opening OP (a region indicated by hatching) may be formed by overlapping a part of the penetration portion 62A (imaginary line) and the penetration portion 62B. In addition, the size of the opening OP can be controlled by adjusting the amount of shift between the opening ratio adjustment member 61A and the opening ratio adjustment member 61B. In this way, the aperture ratio adjustment members 61A and 61B can adjust the aperture ratio by adjusting the amount of shift between each other.

Here, the aperture ratio of the aperture ratio adjustment members 61A and 61B will be described. When the area of the reference region when viewed from the irradiation direction is 100%, the aperture ratio is the total ratio of the area of the openings OP formed in the reference region. Here, the reference area may be the area of the portion overlapping with the substrate 11 denoted by “E1” in FIG. 1. Alternatively, in a state where the substrate 11 is not placed, the area of the portion overlapping with the placing member 12 may be set as the reference area. In the example shown in FIG. 3(a), the combined structure of the aperture ratio adjusting members 61A and 61B does not have the opening OP, so the aperture ratio becomes 0%. The aperture ratio is increased by adjusting the shift amount of the aperture ratio adjusting members 61A, 61B or adjusting the size of the penetration portions 62A, 62B to increase the opening OP. In addition, in the combined structure of the aperture ratio adjusting members 61A and 61B, the upper limit of the aperture ratio when the penetration portions 62A and 62B are completely overlapped. That is, even if the penetration portions 62A and 62B are completely overlapped, the reference area E1 is blocked by the plate portion of the portion of the aperture ratio adjusting member 61A other than the penetration portion 62A. Therefore, the upper limit of the aperture ratio becomes 100% or less. However, depending on the situation, the aperture ratio may be set to 100% by removing the aperture ratio adjusting members 61A and 61B themselves from the reference region E1. In addition, when the aperture ratio is set to 0%, when electron irradiation is allowed, the plasma P may be continuously generated without performing the intermittent control of the plasma P as shown in FIG. 2. In addition, when the aperture ratio is set to 0%, the supply PM may be attracted by an electric field without irradiating the substrate 11 with ultraviolet light UV.

In addition, the shape of the aperture ratio adjustment member is not particularly limited. For example, as shown in FIGS. 3(c) and (d), aperture ratio adjusting members 63A, 63B having comb-tooth-shaped through portions 64A, 64B may also be used. By adjusting the amount of displacement of the through portions 64A, 64B of the aperture ratio adjustment members 63A, 63B, the aperture ratio can be set to 0% as shown in Figure 3(c), or it can be increased as shown in Figure 3(d). Large opening rate. In addition, a flat nest structure can also be used. In addition, various shapes of penetrating portions other than the example shown in FIG. 3 may be adopted. In addition, the number of aperture ratio adjusting members can be further increased. By adopting various combinations, the structure related to the combination of the aperture ratio adjusting member can adjust the aperture ratio from 0% to 100%.

In addition, the number of aperture ratio adjusting members may be one. At this time, as shown in FIG. 7(a), a structure in which a plate 200 covering one of the upper pieces of the substrate 11 is used for blocking is adopted. In this structure, the supply PM is detoured in from the outside of the plate 200 and irradiated. In the configuration of FIG. 7(a), the aperture ratio when the reference area E1 is used as a reference is 0%. However, when the size of the opening into which the supply PM bypasses is large, assuming that the opening is compared with the reference area E1, the size of the opening can also be a size equivalent to 100% of the opening ratio. In such a configuration, the ratio of the opening portion to the cross-sectional area of the chamber 2 is adjusted. In the case of allowing the irradiation of electrons, the plasma P may be continuously generated without performing the intermittent control of the plasma P as shown in FIG. 2.

For example, in the form shown in FIG. 3, the size of the penetration portion is smaller than that of the substrate 11. However, the penetration portions of the aperture ratio adjusting members 201 and 202 may be formed larger as shown in FIG. 7(b). For example, the size of the penetration portion may be a size of "the size of the substrate 11/2" or the like. At this time, by adjusting the overlapped aspect of the aperture ratio adjusting members 201 and 202, the uneven distribution is suppressed.

Next, the effect of the negative ion generator 1 of this embodiment will be described.

The negative ion generator 1 of the present embodiment is provided with an ultraviolet light suppression mechanism 60 that suppresses ultraviolet light UV directed to the object arranging section 3 between the anion generating section 4 and the object arranging section 3. When the negative ion generating part 4 generates the plasma P in order to generate negative ions, the plasma light including ultraviolet light UV is directed in the direction of the substrate 11 arranged on the object arrangement part 3. At this time, by suppressing the ultraviolet light UV toward the substrate 11 by the ultraviolet light suppression mechanism 60, the ultraviolet light UV irradiated on the substrate 11 can be reduced or blocked. In summary, damage to the substrate 11 can be suppressed.

The ultraviolet light suppression mechanism 60 has aperture ratio adjustment members 61A and 61B arranged between the negative ion generating part 4 and the object arrangement part 3 in the chamber 2 and for suppressing the passage of ultraviolet light UV. At this time, even if the overall shape of the cavity 2 is not changed (for example, as shown in FIG. 6 ), only by adding aperture ratio adjusting members 61A and 61B to the existing cavity 2, it is possible to suppress the ultraviolet light UV toward the substrate 11.

The aperture ratio adjusting members 61A and 61B suppress the passage of ultraviolet light UV and allow the passage of negative ions. At this time, even if a complicated mechanism for moving the member as shown in FIG. 4 is not provided, it is possible to suppress the ultraviolet light UV toward the substrate 11.

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

For example, the configuration of the negative ion generator 1 shown in FIG. 4 may also be adopted. In the example shown in FIG. 4, the ultraviolet light suppression mechanism 60 may have a switching section 67 that switches the opening and closing member 66 (member) at the point when the plasma P is generated by the negative ion generating section 4 and at the point when the plasma P is stopped. s position. The opening and closing member 66 is a member facing the substrate 11 and the placing member 12 on the downstream side in the irradiation direction. The opening and closing member 66 is a flat plate member that does not have a through portion as shown in FIG. 3. The switching unit 67 can rotate or reciprocate the opening and closing member 66 by applying a driving force to it. Thereby, the switching portion 67 can switch between the state where the substrate 11 is covered with the opening and closing member 66 and the state where the opening and closing member 66 is retracted to expose the substrate 11.

At this time, at the time when the plasma P is generated (the "ON" time in FIG. 2), the switching section 67 arranges the opening and closing member 66 between the negative ion generating section 4 and the substrate 11 to block the ultraviolet light UV toward the substrate 11 . On the other hand, at the time when the plasma P is stopped (the “OFF” time in FIG. 2 ), the switching section 67 can irradiate the substrate 11 with the negative ions generated by the negative ion generating section 4 by removing the opening and closing member 66. According to the structure shown in FIG. 4, when the plasma P is generated, the opening/closing member 66 without an opening can more reliably block the ultraviolet light UV compared to the structure using the aperture ratio adjusting member shown in FIG. In addition, when the plasma P is stopped, by exposing the substrate 11, more negative ions can be irradiated to the substrate 11 compared to the structure using the aperture ratio adjusting member shown in FIG. 1.

In addition, the structure of the negative ion generator 1 shown in FIG. 5 may also be adopted. In the example shown in FIG. 5, the magnetic field forming part 80 is provided in the space SP2 on the side of the substrate 11 rather than the aperture ratio adjusting members 61A and 61B. The magnetic field forming unit 80 includes magnetic field generating devices 81 respectively provided on the positive side and the negative side in the Y-axis direction with the chamber 2 interposed therebetween. The magnetic field forming part 80 forms a magnetic field along the direction of the mounting surface 12 a of the mounting member 12. That is, the magnetic field forming unit 80 forms a magnetic field along the direction of the irradiated surface 11 a of the substrate 11. The direction along the mounting surface 12a and the irradiated surface 11a means the direction substantially parallel to these surfaces. In the example shown in FIG. 5, the magnetic flux B generated by the magnetic field generating device 81 extends substantially parallel to the Y-axis direction. The magnetic field forming unit 80 can trap electrons by forming a magnetic field near the substrate 11. Thereby, the magnetic field forming part 80 can reduce the amount of electrons irradiated on the substrate 11. Therefore, by adopting the structure shown in FIG. 5, it is also possible to continuously generate the plasma P without performing the intermittent control of the plasma P as shown in FIG.

Furthermore, the configuration related to the combination of the magnetic field forming unit 80, the object arranging unit 3, and the voltage applying unit 8 can function as a discharge unit 90 that performs magnetron discharge. In addition, the negative ion generator 4 can function as a radical supply source that generates radicals. The discharge part 90 is a mechanism capable of performing magnetron discharge using radicals supplied from a radical supply source. Thereby, the discharge part 90 can also generate negative ions irradiated on the substrate 11 through the discharge of the magnetron.

Specifically, the magnetic field forming unit 80 can apply a magnetic field substantially parallel to the irradiated surface 11 a of the substrate 11. That is, a magnetic field substantially parallel to the irradiated surface 11a is formed at the position of the irradiated surface 11a (and the placing surface 12a). In addition, the voltage applying unit 8 can apply a bias voltage perpendicular to the irradiated surface 11 a of the substrate 11. In this way, the discharge part 90 can perform "E×B" magnetron discharge at a position near the irradiated surface 11a. In addition, the negative ion generator 4 can supply a large amount of radicals from the high-density plasma P. Thereby, unlike the gas in the ground state, discharge can be easily performed, and modification by plasma irradiation can be performed. In addition, although new plasma light is generated by the discharge of the magnetron, it is easier to discharge than the plasma P of the negative ion generating portion 4, so there is less ultraviolet light. Therefore, damage to the substrate 11 can be suppressed within an allowable range. With such a magnetron discharge, the substrate 11 serving as the anode is irradiated with newly generated negative ions and electrons.

In addition, negative ions and electrons exhibit the behavior of circling around the magnetic flux B. At this time, the electrons orbit around the magnetic flux B with a small diameter, and the negative ions orbit around the magnetic flux B with a large diameter. Therefore, by adjusting the magnetic field of the magnetic field forming portion 80, the negative ions with larger cyclotrons can contact the substrate 11 as much as possible, while the electrons with smaller cyclotrons do not contact the substrate 11 as much as possible. Thereby, it is easier to irradiate the substrate 11 with negative ions than electrons.

In the above-mentioned embodiment and modification examples, by providing a new member in the chamber 2, the ultraviolet light suppression mechanism is constituted. Alternatively, the ultraviolet light suppression mechanism may be constituted by a chamber 102 in which ultraviolet light UV is blocked by a wall between the negative ion generating part 4 and the object arrangement part 3. At this time, it is possible to suppress the ultraviolet light UV directed to the substrate 11 without adding another member as shown in FIGS. 1 and 4. Specifically, as shown in FIG. 6, the object arranging portion 3 and the substrate 11 may be arranged at positions where the ultraviolet light UV from the plasma P is not directly irradiated.

The chamber 102 shown in FIG. 6 includes a plasma chamber RM1 for generating plasma P and an irradiation chamber RM2 for irradiating the substrate 11 with negative ions. The plasma chamber RM1 is a space corresponding to the internal space of the chamber 2 in FIG. 1, and is formed by a space surrounded by the wall portions 2a to 2d. The irradiation chamber RM2 is formed by a space extending from the end of the plasma chamber RM1 on the negative side in the X-axis direction to the negative side in the Y-axis direction. Specifically, the irradiation chamber RM2 includes a wall portion 2e that extends the wall portion 2a to the negative side of the Y-axis direction; a wall portion 2f that extends from the wall portion 2c to the negative side of the Y-axis direction; and a wall portion 2g that connects the wall The ends of the parts 2e and 2f on the negative side in the Y-axis direction are mutually. In the plasma chamber RM1, the constituent elements of the negative ion generator 4 are provided at the same positions as in FIG. 1. On the other hand, the object arrangement part 3 is provided in the wall part 2e of the irradiation chamber RM2.

The direction (X-axis direction) orthogonal to the irradiated surface 11a of the substrate 11 is defined as the irradiation direction. At this time, the irradiation chamber RM2 in which the object arranging portion 3 is installed is arranged at a position deviated from the plasma chamber RM1 in a direction orthogonal to the irradiation direction (here, the Y-axis direction). In addition, the irradiation chamber RM2 is arranged on the downstream side in the irradiation direction than the plasma gun 14 and the anode 16 and on the downstream side in the irradiation direction than the edge Pa of the plasma P. In addition, the edge Pa of the plasma P indicates the boundary portion of the light emission range that can be visually confirmed when the plasma P is generated at the maximum output. In addition, due to the difference in the luminous intensity of the plasma P, its outline has a certain width.

Due to this positional relationship, when viewed from the substrate 11, the plasma P cannot be directly observed. Specifically, when the negative ion generating portion 4 side is viewed from the reference position on the substrate 11 side, all or part of the plasma P cannot be observed. For example, when the end of the substrate 11 is set as the reference position P1, the arrangement may be such that the edge Pa of the plasma P cannot be observed from the reference position P1, or the center position of the anode 16 cannot be observed from the reference position P1. The configuration of CP2 can also be a configuration in which the center position CP1 (the center position of the area between the plasma gun 14 and the anode 16) of the plasma P cannot be observed from the reference position P1, or it cannot be observed from the reference position P1 The configuration of the center position CP3 of the plasma gun 14. In addition, the state where the center position CP1 cannot be observed from the reference position P1 refers to a state where the virtual line VL connecting the reference position P1 and the center position CP1 is interfered by the wall of the chamber 102 (see FIG. 6). In addition, the center of the mounting member 12 may be set as the reference position P2 on the side of the substrate 11. By allowing these positional relationships to be established, the ultraviolet light UV from the plasma P toward the substrate 11 is blocked by the wall portion 2 c of the chamber 102. In summary, the cavity 102 constitutes the ultraviolet light suppression mechanism 60.

In addition, the negative ion generator 1 shown in FIG. 6 also has a magnetic field forming portion 80 that forms a magnetic field along the direction of the irradiated surface 11a and the placement surface 12a of the substrate 11. Thereby, the negative ions are irradiated onto the substrate 11 by the discharge of the magnetron. In addition, the magnetic field forming portion 80 may be omitted.

For example, in the above-mentioned embodiment, the plasma gun 14 is a pressure gradient type plasma gun, but the plasma gun 14 is not limited to a pressure gradient type plasma gun as long as it can generate plasma in the chamber 2.

In addition, in the above-mentioned embodiment, only one set consisting of the plasma gun 14 and the anode 16 for guiding the plasma P is provided in the chamber 2, but multiple sets may be provided. In addition, plasma P may be supplied from a plurality of plasma guns 14 to one location.

1: Anion generator 2: chamber 3: Object placement department 4: Negative ion generation part 11: Board (object) 60: Ultraviolet light suppression mechanism 61A, 61B, 63A, 63B: aperture ratio adjustment member (member) 66: Opening and closing member (member) 67: Switching part 102: Chamber (ultraviolet light suppression mechanism)

[Fig. 1] is a schematic cross-sectional view showing the structure of the negative ion generator of this embodiment. Fig. 2 is a graph showing the timing of the ON/OFF of plasma P and the flight status of positive ions and negative ions to the object. [Fig. 3(a)~(d)] is a schematic diagram showing an example of an aperture ratio adjusting member. [Fig. 4] is a schematic cross-sectional view showing the structure of a negative ion generator according to a modification. [Fig. 5] A schematic cross-sectional view showing the structure of a negative ion generator according to a modification. [Fig. 6] is a schematic cross-sectional view showing the structure of a negative ion generator of a modification. [FIG. 7(a), (b)] is a schematic enlarged view showing the structure around the substrate of the negative ion generator of the modification.

1: Anion generator

2: chamber

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

3: Object placement department

4: Negative ion generation part

6: Gas supply department

7: Circuit Department

8: Voltage application part

11: Board (object)

11a: illuminated surface

12: Mounting components

12a: Mounting surface

13: connecting member

14: Plasma gun

16: anode

21: Cathode

22: The first middle electrode

23: 2nd middle electrode

26: Gas supply port

30: Variable power supply

31: 1st wiring

32: 2nd wiring

36: Power

37: 3rd wiring

50: Control Department

51: Gas supply control unit

52: Plasma Control Department

53: Voltage Control Department

60: Ultraviolet light suppression mechanism

61A, 61B: Aperture ratio adjustment member

E1: Reference area

P: Plasma

PM: supplies

R1, R2, R3: resistor

SP1, SP2: Space

SW1, SW2: switch

UV: Ultraviolet light

X, Y, Z: axis direction

Claims (5)

A negative ion generating device that generates negative ions and irradiates them to an object, which is equipped with: The chamber is used to generate the aforementioned negative ions inside; The negative ion generating part generates the aforementioned negative ions by generating plasma in the aforementioned chamber; The object arranging part is for arranging the aforementioned objects; and The ultraviolet light suppression mechanism suppresses ultraviolet light directed to the object placement portion between the negative ion generation portion and the object placement portion. The negative ion generating device according to claim 1, wherein: The ultraviolet light suppression mechanism has a member arranged between the negative ion generating part and the object arrangement part in the chamber and for suppressing the passage of the ultraviolet light. The negative ion generating device according to claim 2, wherein: The aforementioned member suppresses the passage of the aforementioned ultraviolet light and allows the passage of the aforementioned negative ions. The negative ion generating device according to claim 2, wherein: The ultraviolet light suppression mechanism has a switching part, and the switching part switches the position of the member at the point when the plasma is generated by the negative ion generating part and at the point when the plasma is stopped. The negative ion generating device according to any one of claim 1 to claim 4, wherein: The ultraviolet light suppression mechanism is constituted by the chamber for blocking the ultraviolet light with a wall between the negative ion generating part and the object arrangement part.

Images