TW202301428A - Negative ion irradiation device and control method thereof wherein the negative ion irradiation device includes a control unit and a gas supply unit - Google Patents

Abstract

The present invention provides a negative ion irradiation device and a control method of the negative ion irradiation device that can improve the manufacturing efficiency and the quality of a compound semiconductor. A control unit (50) controls a gas supply unit (40) to supply gas into a vacuum chamber (10). The gas supply unit (40) supplies a gas containing the same element as the ions forming the compound semiconductor (11). Therefore, the same element as the ions forming the compound semiconductor (11) exists in the vacuum chamber (10). Furthermore, the control unit (50) controls a plasma generator (14) to generate a plasma (P) and an electron in the vacuum chamber (10) and stop the generation of the plasma (P) to generate a negative ion by the electron and the gas, and irradiates the compound semiconductor (11) with the negative ion.

Description

Negative ion irradiation device and control method of negative ion irradiation device

This application claims priority based on Japanese Patent Application No. 2018-134880 filed on July 18, 2018. The entire content of this Japanese application is incorporated in this specification by reference. The invention relates to a negative ion irradiation device and a control method for the negative ion irradiation device.

Conventionally, what is described in Patent Document 1 is known as a compound semiconductor. Crystal defects increase on the single crystal substrate constituting this compound semiconductor. In Patent Document 1, an attempt is made to reduce crystal defects of a single crystal substrate by devising a manufacturing method. (Prior Art Literature) (patent documents) Patent Document 1: Japanese Patent Laid-Open No. 2014-22711

(Problem to be solved by the present invention) However, when manufacturing a single crystal substrate, it is difficult to prevent the generation of crystal defects even if the manufacturing method is devised. Furthermore, when crystal defects are generated on a single crystal substrate, there is no practical method for filling the crystal defects. Therefore, the crystal defects of the single crystal substrate are used as they are. The grade (quality) of the single crystal substrate is determined according to the amount of crystal defects, and the usage is determined according to the grade. Therefore, there is a problem that the production efficiency of the compound semiconductor is lowered due to the limited number of single crystal substrates that can be used for the compound semiconductor. On the other hand, there is a problem that, when a low-grade single crystal substrate is used as a compound semiconductor, the quality of the compound semiconductor decreases. Therefore, an object of the present invention is to provide a negative ion irradiation device and a control method of the negative ion irradiation device capable of improving the production efficiency and quality of compound semiconductors. (means to solve problems) In order to solve the above-mentioned problems, the anion irradiation device of the present invention irradiates negative ions to compound semiconductors, and the negative ion irradiation device includes: a chamber for generating negative ions inside; and a gas supply unit for supplying gas containing the same element as ions forming the compound semiconductor. The plasma generating part generates plasma and electrons in the chamber; the disposing part disposes the compound semiconductor; The plasma generating unit generates plasma and electrons in the chamber, and by stopping the generation of plasma, negative ions are generated from the electrons and gas, and the negative ions are irradiated to the compound semiconductor. In the negative ion irradiation apparatus of this invention, a control part controls a gas supply part, and supplies gas into a chamber. The gas supply unit supplies gas containing the same element as ions forming the compound semiconductor. Therefore, the same elements as ions forming the compound semiconductor exist in the chamber. Furthermore, the control unit controls the plasma generating unit to generate plasma and electrons in the chamber, and by stopping generation of the plasma, negative ions are generated from the electrons and the gas, and the negative ions are irradiated onto the compound semiconductor. Thereby, negative ions of the same element as ions forming the compound semiconductor are irradiated to the compound semiconductor. Thereby, the negative ions enter the crystal defects derived from the negative ions in the compound semiconductor, so that the crystal defects can be filled. Since crystal defects of the compound semiconductor can be filled in this way, the quality of the compound semiconductor can be improved. Also, even if the grade of the compound semiconductor is not sufficient before negative ion irradiation, the quality can be improved by negative ion irradiation, so the necessity of screening the grade of the single crystal substrate in advance can be reduced. Through the above, the production efficiency and quality of compound semiconductors can be improved. The control method of the negative ion irradiation device of the present invention is a control method of the negative ion irradiation device for irradiating negative ions to the compound semiconductor. The negative ion irradiation device is provided with: a chamber for generating negative ions inside; The gas of the same element; the plasma generation part generates plasma and electrons in the chamber; the configuration part arranges the compound semiconductor; and the control part controls the negative ion irradiation device. The control method of the negative ion irradiation device includes: gas supply process, The control part controls the gas supply part to supply gas into the chamber; and the negative ion irradiation process controls the plasma generation part by the control part to generate plasma and electrons in the chamber, and by stopping the generation of plasma, the Electrons and gas generate negative ions, and the negative ions are irradiated to the compound semiconductor. By the control method of the negative ion irradiation device of the present invention, the same purpose and effect as those of the above-mentioned negative ion irradiation device can be obtained. (Effect of Invention) According to the present invention, it is possible to provide a negative ion irradiation device and a control method of the negative ion irradiation device capable of improving the production efficiency and quality of compound semiconductors.

Hereinafter, a negative ion irradiation device according to an embodiment of the present invention will be described with reference to the attached drawings. In addition, in the drawings, the same reference numerals are attached to the same elements, and overlapping explanations are omitted. First, referring to FIG. 1 and FIG. 2, the structure of the negative ion irradiation apparatus which concerns on embodiment of this invention is demonstrated. 1 and 2 are schematic cross-sectional views showing the configuration of a negative ion irradiation device according to this embodiment. FIG. 1 shows the state of operation when plasma is generated, and FIG. 2 shows the state of operation when plasma is stopped. As shown in FIG. 1 and FIG. 2, the negative ion irradiation apparatus 1 of this embodiment is a device which applies the film-forming technology used for the so-called ion plating method to negative ion irradiation. In addition, for convenience of explanation, an XYZ coordinate system is shown in FIGS. 1 and 2 . The Y-axis direction is the direction in which the compound semiconductor will be described later. The X-axis direction is the thickness direction of the compound semiconductor. The Z-axis direction is a direction perpendicular to the Y-axis direction and the X-axis direction. The anion irradiation apparatus 1 may be a so-called horizontal anion irradiation apparatus in which the compound semiconductor 11 is arranged and transported in the vacuum chamber 10 so that the thickness direction of the compound semiconductor 11 becomes substantially vertical. At this time, the Z-axis and Y-axis directions are horizontal directions, and the X-axis direction is a vertical direction and a plate thickness direction. In addition, the negative ion irradiation device 1 may also be a so-called vertical negative ion irradiation device in which the compound semiconductor 11 is placed in a horizontal direction (X-axis direction in FIGS. 1 and 2 ) so that the thickness direction of the compound semiconductor 11 The compound semiconductor 11 is arranged and transported in the vacuum chamber 10 in a state where the semiconductor 11 is erected or tilted from the erected state. At this time, the X-axis direction is the horizontal direction, the thickness direction of the compound semiconductor 11 is the plate thickness direction, the Y-axis direction is the horizontal direction, and the Z-axis direction is the vertical direction. An anion irradiation device according to an embodiment of the present invention will be described below by taking a horizontal anion irradiation device as an example. The negative ion irradiation device 1 includes a vacuum chamber 10 , a transport mechanism (disposition unit) 3 , a plasma generation unit 14 , a gas supply unit 40 , a circuit unit 34 , a voltage application unit 90 , and a control unit 50 . The vacuum chamber 10 is a member for accommodating the compound semiconductor 11 and performing a film-forming process. The vacuum chamber 10 has a transport chamber 10a for transporting the compound semiconductor 11, a generation chamber 10b for generating negative ions, and a plasma port for receiving the plasma P irradiated in the form of a beam from the plasma gun 7 into the vacuum chamber 10. 10c. The transport chamber 10a, the generation chamber 10b, and the plasma port 10c communicate with each other. The transport chamber 10a is set along a predetermined transport direction (arrow A in the figure) (along the Y axis). Also, the vacuum chamber 10 is made of a conductive material and is connected to a ground potential. A heating unit 30 for heating the compound semiconductor 11 is provided in the transfer chamber 10a. The heating unit 30 is provided on the upstream side in the conveyance direction from the communicating portion with the production chamber 10b in the conveyance chamber 10a. Therefore, negative ions from the generation chamber 10b are irradiated to the compound semiconductor 11 in a heated state. The production chamber 10b has, as a wall portion 10W, a pair of side walls along the conveyance direction (arrow A), a pair of sidewalls 10h, 10i along a direction (Z-axis direction) intersecting the conveyance direction (arrow A), and a pair of sidewalls 10i along the X-axis. Bottom wall 10j arranged in cross direction. The transport mechanism 3 transports the compound semiconductor holding member 16 holding the compound semiconductor 11 in a state facing the production chamber 10b in the transport direction (arrow A). The transport mechanism 3 functions as a disposing unit for disposing the compound semiconductor 11 . For example, the compound semiconductor holding member 16 is a frame holding the outer peripheral edge of the compound semiconductor 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 along the conveyance direction (arrow A), and convey along the conveyance direction (arrow A) while supporting the compound semiconductor holding member 16 . In addition, the compound semiconductor 11 is a plate-shaped substrate. The material and the like of the compound semiconductor 11 will be described later. Next, the configuration of the plasma generation unit 14 will be described in detail. The plasma generator 14 generates plasma and electrons in the vacuum chamber 10 . The plasma generator 14 has a plasma gun 7 , a steering coil 5 , and a hearth mechanism 2 . The plasma gun 7 is, for example, a pressure gradient type plasma gun, and its main body is connected to the generation chamber 10b through a plasma port 10c provided on the side wall of the generation 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 into the generation chamber 10b from the plasma port 10c in the form of a beam. Thereby, plasma P is generated in the generation chamber 10b. One end of the plasma gun 7 is closed by a cathode 60 . A first intermediate electrode (grid) 61 and a second intermediate electrode (grid) 62 are arranged concentrically between the cathode 60 and the plasma port 10c. A ring-shaped permanent magnet 61 a for converging the plasma P is built in the first intermediate electrode 61 . An electromagnet coil 62 a is also built in the second intermediate electrode 62 for converging the plasma P. When the plasma gun 7 generates negative ions, the plasma P is generated intermittently in the generation chamber 10b. Specifically, the plasma gun 7 is controlled by the control unit 50 described later so that the plasma P is generated intermittently in the generation chamber 10 b. This control will be described in detail in the description of the control unit 50 . 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 generation chamber 10b. The steering coil 5 is excited by a steering coil power supply (not shown). The hearth mechanism 2 is a mechanism for guiding the plasma P from the plasma gun to a desired position. The hearth mechanism 2 has a main hearth 17 and a ring hearth 6 . When film formation is performed using the negative ion irradiation device 1 , the main furnace 17 functions as an anode for holding film formation materials. However, when generating negative ions, the plasma is guided to the ring hearth 6 so that the plasma P is not guided to the film-forming material. Therefore, when the negative ion irradiation device 1 performs only negative ion irradiation without film formation, the film formation material need not be held by the main hearth 17 . Alternatively, the hearth mechanism 2 may be configured to guide only the plasma P. The ring hearth 6 is the anode with electromagnets for inducing the plasma P. The ring hearth 6 is disposed around the filling portion 17 a of the main hearth 17 . 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 sequentially provided in the X-axis negative direction when viewed from the conveying mechanism 3 , but the permanent magnet portion 20 and the coil 9 may be sequentially provided in the X-axis negative direction. The gas supply unit 40 is arranged outside the vacuum chamber 10 . The gas supply part 40 supplies gas into the vacuum chamber 10 through the gas supply port 41 provided in the side wall (for example, side wall 10h) of the generation chamber 10b. Specific examples of the gas will be described later. The position of the gas supply port 41 is preferably a position near the boundary between the generation chamber 10b and the transfer chamber 10a. At this time, since the gas from the gas supply unit 40 can be supplied to the vicinity of the boundary between the generation chamber 10b and the transfer chamber 10a, negative ions to be described later are generated near the boundary. Therefore, the generated negative ions can be suitably implanted into the compound semiconductor 11 in the transport chamber 10a. In addition, the position of the gas supply port 41 is not limited to the vicinity of the boundary between the generation 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 furnace 17 of the furnace mechanism 2 . Thereby, the variable power supply 80 generates a potential difference between the cathode 60 of the plasma gun 7 and the main well 17 of the well 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 well 17 (anode) of the well 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 production chamber 10 b, and the other end is electrically connected to the variable power supply 80 via the second wiring 72 . That is, the resistor R3 is connected in series between the wall portion 10W of the generation chamber 10b and the variable power supply 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 supply 80 via the second wiring 72 . That is, the resistor R4 is connected in series between the ring hearth 6 and the variable power supply 80 . The short-circuit switches SW1 and SW2 are switching parts that are switched to an ON/OFF (opened/closed) state by receiving a command signal from the control part 50, respectively. The short-circuit switch SW1 is connected in parallel with the resistor R2. The short-circuit switch SW1 is in an OFF state when plasma P is generated. Thereby, since the second intermediate electrode 62 and the variable power source 80 are electrically connected to each other via the resistor R2 , current hardly flows between the second intermediate electrode 62 and the variable power source 80 . As a result, the plasma P from the plasma gun 7 is emitted into the vacuum chamber 10 . In addition, when the plasma P from the plasma gun 7 is emitted into the vacuum chamber 10 , instead of making it difficult for the current to flow to the second intermediate electrode 62 , it is possible to make it difficult for the current to flow to the first intermediate electrode 61 . At this time, the short-circuit switch SW1 is not connected to the second intermediate electrode 62 side but is connected to the first intermediate electrode 61 side. On the other hand, when the plasma P is stopped, the short-circuit switch SW1 is turned ON. As a result, the electrical connection between the second intermediate electrode 62 and the variable power source 80 is short-circuited, so that a current flows between the second intermediate electrode 62 and the variable power source 80 . That is, a short-circuit current flows to the plasma gun 7 . As a result, the plasma P from the plasma gun 7 is not emitted into the vacuum chamber 10 . When negative ions are generated, the ON/OFF state of the short-circuit switch SW1 is switched by the control unit 50 at predetermined intervals, whereby the plasma P from the plasma gun 7 is intermittently generated in the vacuum chamber 10 . That is, the short-circuit switch SW1 is a switching unit for switching supply and cutoff of the plasma P in the vacuum chamber 10 . The short-circuit switch SW2 is connected in parallel with the resistor R4. The ON/OFF state of the short circuit switch SW2 is switched by the control unit 50 depending on whether the plasma P is guided to the main well 17 side or to the ring well 6 side. When the short-circuit switch SW2 is in the ON state, since the electrical connection between the ring well 6 and the variable power supply 80 is short-circuited, current flows more easily to the ring well 6 than to the main well 17 . Thereby, the plasma P is easily guided to the ring hearth 6 . On the other hand, if the short-circuit switch SW2 is in the OFF state, the ring hearth 6 is electrically connected to the variable power supply 80 via the resistor R4. Therefore, compared with the ring hearth 6, the current flows to the main hearth 17 more easily, so that the plasma P is easily guided to the main hearth 17 side. In addition, when negative ions are generated, the short-circuit switch SW2 is kept in the ON state. When the negative ion irradiation device 1 is not performing film formation, the short-circuit switch SW2 may be kept in the ON state. The voltage applying unit 90 can apply a positive voltage to the formed compound semiconductor (object) 11 . The voltage application unit 90 includes a bias circuit 35 and trolley wires 18 . The bias circuit 35 is a circuit for applying a positive bias to the formed compound semiconductor 11 . The bias circuit 35 has a bias power supply 27 for applying a positive bias voltage (hereinafter referred to simply as "bias") to the compound semiconductor 11, a third wiring 73 electrically connecting the bias power supply 27 and the trolley wire 18, and a third wiring 73 provided on the first wiring. 3 The short-circuit switch SW3 of the wiring 73. The bias power supply 27 applies a voltage signal (periodic electric signal) that is a rectangular wave that increases or decreases periodically 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 supply 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 section for switching whether or not a bias voltage is applied to the trolley wire 18 . The ON/OFF state of the short-circuit switch SW3 is switched by the control unit 50 . The short-circuit switch SW3 is turned ON at a predetermined timing when negative ions are generated. 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 an OFF state at a predetermined timing when negative ions are generated. When 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 is applied to the trolley wire 18 . The trolley wire 18 is a wire for supplying power to the compound semiconductor holding member 16 . The trolley wire 18 is extended in the conveyance direction (arrow A) in the conveyance chamber 10a, and is provided. The sliding wire 18 supplies power to the compound semiconductor holding member 16 through the power supply brush 42 by coming into contact with the power supply brush 42 provided on the compound semiconductor holding member 16 . The trolley wire 18 is made of, for example, a stainless steel wire or the like. The control unit 50 is a device that controls the negative ion irradiation device 1 as a whole, and includes an ECU [Electronic Control Unit] that manages the whole 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 units for communication circuits, etc. In the ECU, for example, various functions are realized by loading programs stored in ROM into RAM, and executing the programs loaded into RAM by CPU. An ECU may consist of a plurality of electronic units. The control unit 50 is disposed outside the vacuum chamber 10 . Furthermore, the control unit 50 includes a gas supply control unit 51 for controlling the gas supply by the gas supply unit 40, a plasma control unit 52 for controlling the generation of plasma P by the plasma generation unit 14, and a voltage control unit 90 for controlling the voltage. The applied voltage control part 53. The gas supply control unit 51 controls the gas supply unit 40 to supply gas into the generation chamber 10b. Next, the plasma control unit 52 of the control unit 50 controls the plasma generation unit 14 to intermittently generate the plasma P from the plasma gun 7 in the generation chamber 10 b. For example, the control unit 50 switches the ON/OFF state of the short-circuit switch SW1 at predetermined intervals, whereby the plasma P from the plasma gun 7 is intermittently generated in the generation chamber 10 b. When the short-circuit switch SW1 is OFF (the state of FIG. 1 ), the plasma P from the plasma gun 7 is emitted into the generation chamber 10b, so that the plasma P is generated in the generation chamber 10b. Plasma P has neutral particles, positive ions, negative ions (when there is a negative gas such as oxygen) and electrons as constituent substances. Accordingly, electrons are generated in the generation chamber 10b. When the short-circuit switch SW1 is ON (the state in FIG. 2 ), since the plasma P from the plasma gun 7 is not emitted into the generation chamber 10b, the electron temperature of the plasma P in the generation chamber 10b drops sharply. Therefore, electrons tend to attach to the particles of the gas supplied into the generation chamber 10b. Thereby, negative ions are efficiently generated in the generation chamber 10b. The control unit 50 controls the application of the voltage by the voltage application unit 90 . The control unit 50 applies a voltage through the voltage applying unit 90 at a predetermined timing (for example, timing of stopping the plasma P). In addition, the timing at which the application of the voltage by the voltage application unit 90 is started is set in advance by the control unit 50 . When a positive bias is applied to the compound semiconductor 11 by the voltage applying unit 90 , negative ions in the vacuum chamber 10 are guided to the compound semiconductor 11 . Thereby, negative ions are irradiated to the compound semiconductor. Here, the relationship between the compound semiconductor 11 and negative ions will be described. The compound semiconductor 11 is formed of cations (Cations) and anions (Anions). The compound semiconductor 11 is irradiated with negative ions containing the same element as the anion forming the compound semiconductor 11 . Also, the gas supplied by the gas supply unit 40 contains the same element as the anion forming the compound semiconductor 11 . In addition, the gas also contains rare gases such as Ar. For example, when the compound semiconductor 11 is formed of ZnO, Ga ₂ O ₃ or the like, negative ions such as O ⁻ are irradiated. The gas of the gas supply unit 40 contains O ₂ and the like. When the compound semiconductor 11 is formed of AlN, GaN, etc., negative ions of nitride such as NH ^- are irradiated. In addition, the implanted H is removed by annealing. The gas in the gas supply unit 40 contains NH ₂ , NH ₄ , and the like. In addition, when the compound semiconductor 11 is formed of SiC or the like, negative ions such as C ⁻ , Si ^−, etc. are irradiated. The gas in the gas supply unit 40 contains C ₂ H ₆ , SiH ₄ , and the like. In addition, when the compound semiconductor 11 is SiC, Si can also serve as negative ions, so the cation side can also be irradiated as negative ions. In addition, electron affinity tends to become positive atoms, and molecules tend to become negative ions. Therefore, when the anions of such atoms and molecules are contained in the compound semiconductor 11, negative ions containing the same atoms and molecules can be irradiated. For example, those that are easily negatively ionized include H, He, C, O, F, Si, S, Cl, Br, I, H _{2 , O 2} , Cl ₂ , Br ₂ , I _{2 ,} CH, OH, CN , HCl, HBr, NH ₂ , N ₂ O, NO ₂ , CCl ₄ , SF ₆ etc. Next, referring to FIG. 3 , a method of controlling the negative ion irradiation device 1 will be described. Fig. 3 is a flow chart showing the control method of the negative ion irradiation device 1 of the present embodiment. In addition, here, the compound semiconductor 11 is formed of ZnO, and the case where negative ions of O ⁻ are irradiated will be described as an example. As shown in FIG. 3 , the control method of the negative ion irradiation device 1 includes a gas supply process S10, a plasma generation process S20 (a part of the negative ion irradiation process), and a voltage application process S30 (a part of the negative ion irradiation process). Each process is executed by the control unit 50 . First, the gas supply control unit 51 of the control unit 50 controls the gas supply unit 40 to supply gas into the vacuum chamber 10 (gas supply process S10 ). As a result, the gas of O ₂ is present in the generation chamber 10 b of the vacuum chamber 10 . Then, a plasma generation process S20 is performed. The plasma control unit 52 of the control unit 50 generates plasma P and electrons in the vacuum chamber 10 by controlling the plasma generation unit 14, and by stopping the generation of the plasma P, negative ions (electrons) are generated from the electrons and the gas. Pulp generation process S20). When plasma P and electrons are generated in the generation chamber 10 b of the vacuum chamber 10 , a reaction of “O ₂ +e ⁻ →2O+e ⁻ ” proceeds by the plasma P. Then, when the generation of the plasma P is stopped, the temperature of the electrons in the generation chamber 10b drops sharply, and a reaction of "O+e ^- →O ^- " proceeds. The voltage application process S30 is performed at a predetermined timing after the plasma generation process S20 is performed. In addition, strictly speaking, negative ions are also generated during plasma generation, and when negative ions are irradiated, negative ions generated during plasma generation are also irradiated. The voltage control unit 53 of the control unit 50 controls the voltage application unit 90 and applies a bias voltage to the compound semiconductor 11 (voltage application process S30 ). Thereby, the negative ions 81 of O ⁻ in the generation chamber 10 b are directed toward the compound semiconductor 11 side, and are irradiated to the compound semiconductor 11 (see FIGS. 2 and 4 ). Next, the operation and effect of the negative ion irradiation device 1 and its control method of the present embodiment will be described. In the negative ion irradiation apparatus 1 of the present embodiment, the control unit 50 controls the gas supply unit 40 to supply gas into the vacuum chamber 10 . The gas supply unit 40 supplies a gas containing the same element as the ions forming the compound semiconductor 11 . Therefore, the same elements as ions forming the compound semiconductor 11 exist in the vacuum chamber 10 . Furthermore, the control unit 50 generates plasma P and electrons in the vacuum chamber 10 by controlling the plasma generation unit 14, and by stopping the generation of the plasma P, negative ions are generated from the electrons and the gas, and the negative ions are irradiated. to the compound semiconductor 11. For example, as shown in FIG. 4( a ), negative ions 81 of the same element as ions forming the compound semiconductor 11 are irradiated to the compound semiconductor 11 . Negative ions 81 enter inside from the surface 11 a of the compound semiconductor 11 . Thereby, the negative ions 81 enter into the crystal defect 85 derived from the anion in the compound semiconductor 11, and as shown in FIG. 4(b), the crystal defect 85 can be filled. Here, the advantages of irradiating the compound semiconductor 11 with negative ions will be described with reference to FIGS. 5 and 6 . 5 and 6 show the ionic bond structure of cations 86 and anions 87 forming the compound semiconductor 11 . FIG. 5 is a diagram schematically showing a state when positive ions 83 are implanted into a compound semiconductor as a comparative example. As shown in FIG. 5 , when positive ions 83 are implanted into the compound semiconductor 11 , the positive ions 83 must pass under the influence of the Coulomb force of the cations 86 and anions 87 , making it difficult to smoothly enter the compound semiconductor 11 . In addition, if electrons 82 as secondary electrons are released by the injection of positive ions 83 , there will be a problem that the substrate is charged. On the other hand, when negative ions 81 (see FIG. 6( a )) directed toward the compound semiconductor 11 reach the compound semiconductor 11 , as shown in FIG. 6( b ), they are easily detached by colliding electrons 82 . Therefore, negative ions 81 enter into ionic bonds as particles 81a in which electrons 82 have left the neutral state. The particles 81 a in the neutral state can smoothly enter the interior of the compound semiconductor 11 without being affected by the Coulomb force of the cations 86 and the anions 87 . Therefore, the energy of negative ions 81 may be as low as 70 eV or less, for example. Also, when the negative ions 81 are injected, the substrate will not be charged. In addition, negative ions 81 are implanted into the compound semiconductor 11 in a state heated by the heating unit 30 (see FIG. 1 ). Therefore, the desired element is penetrated deep into the compound semiconductor 11 by concentration diffusion, and the excess element is removed by heat treatment, so that the particles 81a can fill only crystal defects. In addition, for example, as a comparative example, when negative ions are irradiated using a negative ion source, the area that can be irradiated with negative ions is small. On the other hand, the negative ion irradiation device 1 including the plasma generation unit 14 can irradiate the compound semiconductor 11 with negative ions over a large area as in the present embodiment. In addition, for example, as a comparative example, when only negative ions of a single energy are irradiated, the negative ions enter only a predetermined depth position of the compound semiconductor 11, and therefore crystal defects cannot be filled in a wide range in the depth direction. On the other hand, according to the negative ion irradiation device 1 of the present embodiment, since negative ions having a wide energy range can be generated, crystal defects can be filled in a wide range in the depth direction. As described above, the negative ion irradiation device 1 according to the present embodiment can fill the crystal defects of the compound semiconductor 11, so that the quality of the compound semiconductor 11 can be improved. Also, even if the grade of the compound semiconductor 11 is not sufficient before negative ion irradiation, the quality can be improved by negative ion irradiation, so the necessity of screening the grade of the single crystal substrate in advance can be reduced. Through the above, the production efficiency and quality of compound semiconductors can be improved. The control method of the negative ion irradiation device 1 of the present embodiment includes: gas supply process S10, controlling the gas supply part 40 to supply gas into the vacuum chamber 10; negative ion irradiation process (plasma generation process S20, voltage application process S30), controlling The plasma generation unit 14 generates plasma P and electrons in the vacuum chamber 10 , stops generation of the plasma P, generates negative ions from the electrons and gas, and irradiates the compound semiconductor 11 with the negative ions. By the control method of the negative ion irradiation device 1 of the present embodiment, the same functions and effects as those of the above-mentioned negative ion irradiation device 1 can be obtained. One embodiment of the present embodiment has been described above, but the present invention is not limited to the above-mentioned embodiment, and can be modified or applied to other embodiments without changing the gist described in each claim. In addition, in the above-mentioned embodiment, the negative ion irradiation device also has the function as the ion plating type film formation device has been described, however, the negative ion irradiation device may not have the function of the film formation device. Thus, the plasma P can be guided, for example, into an electrode or the like of a wall portion opposite to the plasma gun. For example, in the above-mentioned embodiment, the plasma gun 7 is set as a pressure gradient type plasma gun, but as long as the plasma can be generated in the vacuum chamber 10, the plasma gun 7 is not limited to the pressure gradient type. plasma gun. In addition, in the above embodiment, only one set of the plasma gun 7 and the position for guiding the plasma P (heart mechanism 2 ) is provided in the vacuum chamber 10 , but plural sets may be provided. Also, plasma P may be supplied from a plurality of plasma guns 7 to one position.

1: Negative ion irradiation device (negative ion irradiation device) 3: Conveying mechanism (configuration department) 7: Plasma Gun 10: Vacuum chamber 11: Compound semiconductor 14: Plasma Generation Department 40: Gas supply part 50: Control Department P: Plasma

[ Fig. 1 ] is a schematic cross-sectional view showing the structure of a negative ion irradiation device according to an embodiment of the present invention, and is a diagram showing an operating state when plasma is generated. [ Fig. 2 ] is a schematic cross-sectional view showing the structure of the negative ion irradiation device in Fig. 1 , and is a diagram showing the operating state when the plasma is stopped. [FIG. 3] It is a flow chart which shows the control method of the negative ion irradiation apparatus of this embodiment. [ Fig. 4 ] is a diagram schematically showing how a compound semiconductor is irradiated with negative ions. [ Fig. 5 ] is a diagram schematically showing the state when positive ions are implanted into a compound semiconductor as a comparative example. [ Fig. 6 ] is a diagram schematically showing a state when negative ions are implanted into a compound semiconductor.

1: Negative ion irradiation device

2: Hearth mechanism

3: Conveying mechanism (configuration department)

5: Steering coil

6: ring hearth

7: Plasma Gun

9: Coil

10: Vacuum chamber

10a: Transport chamber

10b: Generation Room

10c: plasma port

10h(10W): side wall

10i(10W): side wall

10j (10W): Bottom wall

11: Compound semiconductor

12: container

14: Plasma Generation Department

15: Conveyor roller

16: Compound semiconductor holding member

17: Main hearth

17a: filling part

18 (90): sliding wire

20:Permanent magnet part

27: Bias power supply

30: heating part

34: Circuit Department

35(90): Bias circuit

40: Gas supply part

41: Gas supply port

42: Power supply brush

50: Control Department

51: Gas supply control unit

52: Plasma Control Department

53:Voltage Control Department

60: Cathode

61: 1st middle electrode

61a: ring permanent magnet

62: The second middle electrode

62a: Electromagnet coil

71: 1st wiring

72: 2nd wiring

73: 3rd wiring

80: variable power supply

A: arrow

P: Plasma

R1: Resistor

R2: Resistor

R3: Resistor

R4: Resistor

SW1: Short circuit switch

SW2: Short circuit switch

SW3: Short circuit switch

Claims (5)

A negative ion irradiation device, which irradiates negative ions to an irradiated body, and the aforementioned negative ion irradiation device has: a chamber capable of disposing the aforementioned irradiated body; a gas supply unit that supplies a gas containing the same element as the ion forming the aforementioned irradiated body; and A plasma generation unit generates plasma and electrons in the chamber; The gas supply unit supplies the gas into the chamber, The plasma generation unit generates the plasma and the electrons in the chamber, stops generation of the plasma, generates the negative ions from the electrons and the gas, and irradiates the negative ions to the irradiated body. Such as the negative ion irradiation device of claim 1, wherein The aforementioned object to be irradiated is manufactured externally in advance. Such as the negative ion irradiation device of claim 1 or 2, wherein A voltage application unit that applies a bias voltage to the irradiated body is further provided. An anion irradiation device according to any one of claims 1 to 3, wherein The aforementioned object to be irradiated is a compound semiconductor. A method for controlling an anion irradiation device for irradiating an irradiated body with negative ions, wherein the anion irradiation device includes: a chamber capable of disposing the aforementioned irradiated body; a gas supply unit that supplies a gas containing the same element as the ion forming the aforementioned irradiated body; and A plasma generation unit generates plasma and electrons in the chamber; The control method of aforementioned negative ion irradiation device comprises: a gas supply process, supplying the aforementioned gas into the aforementioned chamber through the aforementioned gas supply unit; and In the negative ion irradiation process, the plasma and the electrons are generated in the chamber by the plasma generating unit, and by stopping the generation of the plasma, the negative ions are generated from the electrons and the gas, and the negative ions are irradiated onto the The irradiated body.

Images