TWI476805B - Electron gun and the vacuum evacuation apparatus - Google Patents

Description

Electron gun, vacuum processing device

The present invention relates to an electron gun.

The electron gun is a device that accelerates the emitted electrons and converges into a bundle shape, and irradiates the electron beam to the object disposed in the vacuum chamber, for example, by irradiating the electron beam with the object and heating it. The film forming apparatus which performs film formation of a board|substrate in a vacuum atmosphere.

When such an electron beam advances inside the electron gun or inside the vacuum chamber, it collides with the residual gas and generates positively charged ions.

The positive ions are pulled by the space charge of the electron beam and are collected on the central axis of the electron beam, and further toward the cathode electrode having a low potential to advance in the reverse direction along the central axis.

The positive ions generated in the vacuum chamber or near the electron discharge port are eventually pulled toward the cathode electrode and accelerated to collide with the cathode electrode.

Due to the ion impact caused by this collision, the cathode electrode system is damaged, and the electron emission surface is retreated and deformed. In a more serious case, perforation occurs at the center portion, which is the main cause of shortening the life of the cathode electrode. . Further, the collision of the ions causes the cathode electrode to be sputtered, and the scattered cathode electrode material mainly adheres to the anode electrode, which causes a change in the temperature of the anode electrode and the like, and causes a phenomenon such as peeling. The cause of abnormal discharge.

[Patent Document 1] Japanese Patent Publication No. 07-007648

The present invention has been made in order to solve the problems of the prior art described above, and the object thereof is to collide with residual gas for electrons inside a vacuum chamber or inside an electron gun and collide the generated positive ions with the cathode electrode. The situation is prevented, and a long-life electron gun is provided.

The present invention is an electron gun characterized by comprising: a cathode electrode which is heated to emit hot electrons; and a gate electrode for collecting electron beams emitted from the cathode electrode; The anode electrode is provided with an anode hole, and a positive voltage is applied to the cathode electrode, and the thermoelectron passes through the anode hole as an electron beam; and a repeller electrode is opposite to the anode The electrode is applied with a positive voltage and is disposed between the anode electrode and the discharge port for discharging the electron beam, and passes the electron beam along the central axis; and the discharge port passes through the aforementioned repulsive The aforementioned electron beam of the electrode is discharged.

The present invention relates to an electron gun including a casing in which the cathode electrode and the gate electrode are disposed between the anode electrode and the repeller electrode, and the casing is provided with the casing. a portion of the space between the anode electrode and the cathode electrode for evacuating the first vacuum exhaust port, and a portion between the anode electrode and the discharge port in the space in the casing for vacuum evacuation The second vacuum exhaust port.

The present invention is an electron gun in which a pore is formed in the repulsion electrode, and a gas positioned in a space surrounded by the repulsion electrode is passed through the pores 2 Vacuum exhaust port for vacuum exhaust.

The present invention is an electron gun in which the repulsion electrode is formed into a cylindrical shape via a mesh-shaped conductive material.

The present invention is an electron gun, wherein the repulsion electrode is configured such that an inner circumferential surface thereof is located at a side surface of the same cylindrical shape.

The present invention relates to a vacuum processing apparatus comprising: a vacuum chamber; and an electron gun of any of the above, wherein an inside of the vacuum chamber and an inside of the electron gun are connected, and in the vacuum chamber, The object to be irradiated is disposed, and the object to be irradiated is irradiated with the electron beam emitted from the discharge port.

The present invention is generally constructed as described above, and the repulsion electrode is a cylindrical shape or an annular shape in which an electron beam passes through a central axis thereof, and is disposed on the anode electrode and more electronically. Below the beam side.

At the repulsion electrode, a positive voltage is applied to the anode electrode, and the positive ions flying from the discharge port side toward the repulsion electrode are pushed back to the discharge port side.

By pushing the positive electrode on the central axis with the repeller electrode back to the vacuum groove side, it is possible to prevent the damage of the cathode electrode and prolong the life. At the same time, the occurrence of abnormal discharge due to adhesion of the cathode electrode material which was sputtered by ion bombardment (Ion-Bombard) to the anode electrode is lowered.

Further, since the pores are formed at the repulsion electrode, and the space surrounded by the repulsion electrode can be evacuated through the pores, even if the repulsion electrode is provided, It will hinder the exhaust of the intermediate chamber.

Fig. 5 (a) is a vacuum processing apparatus 2 which is an example of the present invention, in which a vapor deposition material 4 is disposed inside a vacuum chamber 18, and a substrate holder is disposed above the vapor deposition material 4 5.

In the vacuum chamber 18, a vacuum pump 6 for vacuum chamber is connected, and the inside of the vacuum chamber 18 is evacuated by the vacuum pump 6 through the vacuum chamber, and the substrate 3 is carried into the vacuum while maintaining the vacuum atmosphere. The inside of the groove 18 is held on the substrate holder 5.

The electron gun 10 of the present invention is mounted on the wall surface of the vacuum chamber 18 or at the top plate. If the electron gun 10 is directly evacuated, the inside of the electron gun 10 is set to be lower than the vacuum chamber 18 and the vacuum is higher. In the atmosphere, the electron beam is discharged from the electron gun 10 into the vacuum chamber 18, and when the vapor deposition material 4 is irradiated, the vapor deposition material 4 is evaporated in a vacuum atmosphere, and the vapor reaches the substrate 3 and is on the surface of the substrate 3. A film of the vapor deposition material 4 is formed.

In Fig. 1, a schematic view of the interior of the electron gun 10 caused by the present invention is shown.

The electron gun 10 is provided with a cylindrical casing 11 in which a discharge port 13 is formed at one end portion of the casing 11. The cathode electrode 21 is disposed on the bottom surface 12 on the side opposite to the discharge port 13. Further, the gate electrode 22 is disposed at a position close to the cathode electrode 21 and separated from each other.

The gate electrode 22 has a ring shape having a gate hole 25 as a through hole at the center, and has the same central axis 28 as the cathode electrode 21 so that the inner surface of the gate hole 25 is adjacent to the cathode side surface. For configuration.

On the side closer to the discharge port 13 than the cathode electrode 21 and the gate electrode 22, the anode electrode 23 and the repeller electrode 24 are arranged in this order from the gate electrode 22 side.

The anode electrode 23 has a ring shape having an anode hole 26 that is a through hole at the center, and the repulsion electrode 24 is a cylindrical shape in which one end faces the cathode electrode 21 side and the other end faces the discharge port 13 side. The central axis 28 of the repeller electrode 24 passes through the center of the cathode electrode 21, and the central axis of the gate electrode 22 and the central axis of the anode electrode 23 are set to coincide with each other. Here, the repulsion electrode 24 has a cylindrical shape such that the electric field inside the repulsion electrode 24 is axisymmetric.

The casing 11 is attached to the vacuum chamber 18 such that the inside of the casing 11 is connected to the inside of the vacuum chamber 18 via the discharge port 13, and the casing 11 is connected to the ground potential together with the vacuum chamber 18. Make a connection.

The power supply device 30 is disposed outside the casing 11 and the vacuum chamber 18, and the electrodes 21 to 24 are connected to the power supply device 30.

The first and second vacuum exhaust ports 34 and 35 are provided in the casing 11, and the first and second vacuum exhaust ports 34 and 35 are connected to the vacuum pumps 16 and 17. Here, the first and second vacuum exhaust ports 34 and 35 are connected to the vacuum pumps 16 and 17, respectively.

When the vacuum processing apparatus 2 is used, the vacuum pump 6 and the vacuum pumps 16 and 17 connected to the first and second vacuum exhaust ports 34 and 35 are operated, and the vacuum chamber 18 is previously provided. The inside is evacuated to the inside of the casing 11.

On the back surface of the cathode electrode 21, a heating device 38 is disposed, and while the heating device 38 is heated and the cathode electrode 21 is heated, a negative voltage with respect to the ground potential is applied to the cathode electrode 21 via the power supply device 30 and The electrode 22 applies the same voltage as the cathode electrode 21. For the anode electrode 23, a positive voltage with respect to the cathode electrode 21 is applied. Here, the anode electrode 23 is connected to the ground potential.

At the cathode electrode 21, a negative high voltage (for example, -40 kV) is applied, and the hot electrons emitted from the cathode electrode 21 are bundled into a bundle shape via the gate electrode 22 and the anode electrode 23, and are passed through the anode electrode. 23 is accelerated and passes through the gate hole 25 and the anode hole 26 and proceeds along the central axis 28 of the repeller electrode 24 to pass through the repeller electrode 24.

By the power supply device 30, a positive voltage is applied to the repeller electrode 24 with respect to the anode electrode 23, but since the central axis of the beam coincides with the central axis 28 of the repeller electrode 24, There will be a case where the axis symmetry of the beam collapses.

When the potentials of the electrodes 21 to 24 are compared, the gate electrode = the cathode electrode < the anode electrode < the repeller electrode is used. Here, the anode electrode 23 is connected to the ground potential.

Reference numerals 31, 32, and 33 are a first bundle coil and a second bundle coil and a wobble coil, respectively, and the first bundle coil 31 is located at the outer side of a portion of the anode electrode 23, and one of the anode electrodes 23 is provided. Part of it is surrounded by the configuration.

The second cluster coil 32 and the wobble coil 33 are positioned closer to the flow side of the electron beam than the first bundle coil 31, and are driven from the first bundle coil 31 in the above-described order to make the orbit of the electron beam. The way to surround is configured. The repulsion electrode 24 is positioned between the first cluster coil 31 and the second bundle coil 32.

The electron beam is bundled by the first and second cluster coils 31 and 32, and is discharged from the discharge port 13 to be irradiated onto the object in the vacuum chamber 18.

The symbol L _{1 of} FIG. 4 is a curve representing the orbital shape of the electron beam when a positive voltage of 300 V is applied to the repeller electrode 24 with respect to the ground potential, and it is confirmed that the system is not replied. The electrodes 24 are slightly identical in shape. Therefore, it can be understood that the repeller electrode 24 to which the positive voltage is applied does not adversely affect the electron beam bundling action of the first and second cluster coils 31 and 32.

4 and FIG. 3, which will be described later, are shown only on one side of the central axis 28 of the electron gun 10 and the repeller electrode 24, in which the exhaust port is disposed.

Further, when the swing coil 33 is operated, the traveling direction of the electron beam emitted from the discharge port 13 is shaken, and the object can be irradiated with a larger area than the cross-sectional area of the electron beam.

The first vacuum exhaust port 34 is connected to an electron gun chamber which is a portion between the anode electrode 23 and the cathode electrode 21 in a space inside the casing 11, and is configured to be a gas located in the electron gun chamber. Vacuum exhaust.

Further, the second vacuum exhaust port 35 is in the middle of the space between the anode electrode 23 and the discharge port 13 in the space inside the casing 11 and is closer to the cathode 21 than the second bundle coil 32. The chamber is connected and configured to evacuate the gas located in the intermediate chamber.

Here, as described above, the electron beam is advanced in the direction in which the central axis 28 extends on the central axis 28 of the repulsion electrode 24, and the second vacuum exhaust port 35 is disposed on the outer side of the repulsion electrode 24. At the office.

The repeller electrode 24 is generally composed of a metal mesh 41 as shown in FIG. 5(b). The gas at the intermediate chamber passes through the mesh 42 of the mesh 41 and is removed from the second vacuum row. The port 35 is evacuated.

Further, in the above-described embodiment, the metal mesh is used, but the electron beam may be advanced in such a manner that the plurality of metal thin rods are positioned at the same cylindrical side surface. The repeller electrodes 24 are formed in a cylindrical shape at equal intervals in parallel. Further, the conductive plate formed with a plurality of fine holes may be formed into a disk shape and used as the repeller electrode 24. Further, a part of the hollow cylinder made of metal may be subjected to slit processing or slitting processing, and may be, for example, a repeller electrode 24 processed into a crown shape or processed into a spiral shape.

The repeller electrode 24 is capable of passing a gas through a fine hole, a slit or a notch, and the passed gas system is evacuated from the second vacuum exhaust port 35.

In the case of the repulsion electrode 24 of either one, when it is in the case of a slit, a notch, a pinhole or other gas passage means, it is preferable not to cause it to cause an orbit to the electron beam. The manner of influence is such that when the repulsion electrode 24 is cut into a plane perpendicularly intersecting the central axis of the electron beam, the gas passage means becomes rotationally symmetrical with the central axis of the electron beam as the center.

If the function of the repulsion electrode 24 is explained, if a positive voltage with respect to the anode electrode 23 is applied to the repulsion electrode 24, the potential at the position of the central axis 28 of the repulsion electrode 24 is compared with The prior art electron gun in which the repulsion electrode 24 is present is raised to the positive voltage side.

The inside of the casing 11 of the electron gun 10 is evacuated by the vacuum from the first and second vacuum exhaust ports 34 and 35, so that the pressure of the electron gun chamber becomes lower than that of the intermediate chamber, and the intermediate chamber is The pressure, which is closer to the portion of the vacuum chamber 18 than the intermediate chamber, becomes lower.

The inside of the vacuum chamber 18 or the portion of the inner portion of the casing 11 that is closer to the vacuum chamber 18 is a portion having a higher pressure, and a large amount of the residual gas system collides with the electron beam, and the residual gas system is ionized. And produces positive ions.

The positive ions generated are concentrated at the central axis of the electron beam having a low potential, and are advanced toward the side of the cathode electrode 21 having a larger negative potential.

In the electron gun 10 of the present invention, at the repeller electrode 24, a voltage which is positive with respect to the anode electrode 23 and a potential of the central axis 28 of the repulsion electrode 24 are applied, and there is no positive application. When the voltage replies the electrode 24, it rises more.

In particular, in the present invention, even when the electron beam emitted from the cathode electrode 21 is advanced on the central axis 28 of the repulsion electrode 24, the repulsion electrode is applied to the repulsion electrode 24, and the repulsion electrode is applied. The potential on the central axis 28 of 24 is at the maximum voltage within the repulsion electrode 24.

Therefore, between the discharge port 13 and the repeller electrode 24, the potential on the side of the repulsion electrode 24 is formed to be higher than the potential on the discharge port 13 side, and a higher electric field is formed inside the vacuum chamber 18 or the repulsion electrode. The positive ions generated in the space closer to the discharge port 13 are pushed back by the electric field, and the electric field formed by the repulsion electrode 24 does not enter the cathode electrode 21 side.

Figure 3 is a simulation result of a positive ion action inside the electron gun 10 when the electron beam is irradiated from the cathode electrode 21 of the electron gun constructed in Fig. 1, and will be pulled toward the cathode. The range in which the electrode 21 is incident on the positive electrode at the cathode electrode 21 is surrounded by a dot line attached to the symbol A.

Further, the range of the position where the positive ions at the cathode electrode 21 are not irradiated even if the electron beam is irradiated is surrounded by a dot line of a symbol B.

The electron gun chamber and the intermediate chamber are vacuum-exhausted from the first and second vacuum exhaust ports 34 and 35, respectively, and the electron gun chamber is set to a pressure of 1 × 10 ^-4 Pa or less, and the intermediate chamber is set. The pressure is 1 × 10 ^-3 Pa or less, and practically, positive ions are hardly generated, and the positive ions incident on the cathode electrode 21 are minute.

The conditions for the simulation are such that the potential of the repulsion electrode 24 is +300 V, the potential of the gate electrode 22 is -40 kV, the potential of the cathode electrode 21 is -40 kV, and the anode electrode 23 is 0 V (ground potential), and electrons. The beam current is 6A. As the initial velocity of the ions, a random thermal velocity of 1000 K was imparted.

Under this condition, it can be known that the positive ions located at the side closer to the discharge port 13 than the repeller electrode 24 do not move to the side of the cathode electrode 21, or are close to or within the vacuum chamber 18. A large amount of positive ions generated in the space of the vacuum chamber 18 are not incident on the cathode electrode 21.

2 is a simulation result of the electron gun in which the repeller electrode 24 is removed from the electron gun 10 of the configuration of FIG. 1, and is an electron gun of FIG. 1 except that the repeller electrode 24 to which a positive voltage is not applied is present. 10 is the simulation result of the electron gun of the same construction.

The positive ion (the range of the symbol A) at a position closer to the discharge port 13 than the portion where the repulsion electrode 24 is located is incident on the cathode electrode 21, and the pressure of the residual gas at this position is high. Therefore, since a large amount of generated positive ions are incident, it can be known that the cathode electrode 21 is rapidly damaged.

Further, in the above embodiments, the vacuum processing apparatus of the present invention has been described as a vapor deposition apparatus. However, the present invention is not limited to the vapor deposition apparatus, and includes other Vacuum processing unit.

Further, in the above-described embodiment, the repulsion electrode 24 has a cylindrical shape both in the inner circumference and the outer circumference. However, if the inner circumferential surface is cylindrical, the outer circumferential surface may not be a cylinder.

The cross-sectional shape of the repulsion electrode is generally circular as in the above embodiment, and is preferably a circular shape that does not affect the orbit of the electron beam. However, it may be considered as a limitation on the configuration of the device or a manufacturing cost. It is a Reuleaux triangle or an epicycloid circle (茧) that generally combines a polygon and an arc.

Further, a repeller electrode having a spiral shape in which the inner peripheral surface can be closely attached to the side surface of the cylindrical shape is included, and a plurality of circular rings electrically connected to each other may be parallel to each other and centered. The repeller electrodes are formed on the same central axis.

Further, the rod-shaped electrodes electrically connected to each other may be disposed parallel to each other on the circumference of one circle and at right angles to the cylinder to constitute a repulsion electrode.

That is, the repeller electrode 24 of the above-described embodiment is configured as an example of a repeller electrode in which the inner peripheral surface is positioned at the side surface of the same cylindrical shape.

Further, it is not limited to the cylinder, and the repeller electrode having a truncated cone shape in which one of the inner circumferential surfaces is wider than the other opening may be used.

2. . . Vacuum processing unit

3. . . Substrate

4. . . Evaporating material

5. . . Substrate holder

6. . . Vacuum pump for vacuum tank

10. . . Electron gun

11. . . Casing

12. . . Bottom

13. . . Export

16, 17. . . Vacuum pump

18. . . Vacuum tank

twenty one. . . Cathode electrode

twenty two. . . Gate electrode

twenty three. . . Anode electrode

twenty four. . . Repulsion electrode

25. . . Gate hole

26. . . Anode hole

28. . . Central axis

31. . . First bundle coil

32. . . Second bundle coil

33. . . Shake coil

34. . . First vacuum vent

35. . . Second vacuum vent

Fig. 1 is a view for explaining an electron gun of the present invention.

Fig. 2 is a view for explaining an action of positive ions inside the electron gun when the repulsion electrode is removed.

Fig. 3 is a view for explaining an operation of a positive ion inside an electron gun as an example of the present invention.

Fig. 4 is a view for explaining an orbital shape of an electron beam of an electron gun of an example of the present invention.

Fig. 5 (a) is a view for explaining a vacuum processing apparatus of one example of the present invention, and Fig. 5 (b) is a view for explaining a repeller electrode formed by a conductive mesh.

10. . . Electron gun

11. . . Casing

12. . . Bottom

13. . . Export

16, 17. . . Vacuum pump

18. . . Vacuum tank

twenty one. . . Cathode electrode

twenty two. . . Gate electrode

twenty three. . . Anode electrode

twenty four. . . Repulsion electrode

25. . . Gate hole

26. . . Anode hole

28. . . Central axis

30. . . Power supply unit

31. . . First bundle coil

32. . . Second bundle coil

33. . . Shake coil

34. . . First vacuum vent

35. . . Second vacuum vent

38. . . heating equipment

Claims (7)

An electron gun characterized by comprising: a cathode electrode for heating and emitting hot electrons; and a gate electrode for collecting electron beams emitted from the cathode electrode; and an anode electrode having An anode hole is provided, and a positive voltage is applied to the cathode electrode, and the hot electrons pass through the anode hole as an electron beam; and a repeller electrode is applied to the anode electrode a positive voltage is provided between the anode electrode and a discharge port for discharging the electron beam, and the electron beam passes through the central axis, and the electron beam passing through the repulsion electrode is discharged from the foregoing The outlet is discharged, and the anode electrode and the repeller electrode are arranged in this order from the gate electrode side at the side of the discharge port from the cathode electrode and the gate electrode. An electron gun characterized by comprising: a cathode electrode for heating and emitting hot electrons; and a gate electrode for collecting electron beams emitted from the cathode electrode; and an anode electrode having An anode hole is provided with a positive voltage applied to the cathode electrode, and the aforementioned thermoelectron passes through the anode hole as an electron beam; and a cylindrical repeller electrode is applied with a positive voltage relative to the anode electrode, and passes the electron beam passing through the anode hole along the central axis along the central axis, and passes The electron beam of the repulsion electrode is discharged from the discharge port, and the electron gun includes a casing in which the cathode electrode and the gate electrode are disposed between the anode electrode and the repeller electrode. The body is provided with a first vacuum exhaust port for evacuating a portion between the anode electrode and the cathode electrode in a space in the casing, and the anode electrode in a space in the casing A portion between the discharge ports is a second vacuum exhaust port for vacuum evacuation. An electron gun characterized by comprising: a cathode electrode for heating and emitting hot electrons; and a gate electrode for collecting electron beams emitted from the cathode electrode; and an anode electrode having An anode hole is provided with a positive voltage applied to the cathode electrode, and the hot electrons pass through the anode hole as an electron beam; and a cylindrical repeller electrode is opposite to the anode electrode a positive voltage is applied, and the electron beam that has passed through the anode hole passes along the central axis on the central axis, and the electron beam that has passed through the repulsion electrode is released from the discharge port. At the repeller electrode, a fine hole is formed. The gas positioned in the space surrounded by the repulsion electrode is vacuum-exhausted from the second vacuum exhaust port through the pores. The electron gun according to the first or second aspect of the invention, wherein the repeller electrode is formed with a fine hole, and the gas located in a space surrounded by the repulsion electrode passes through The pores are evacuated from the second vacuum exhaust port. The electron gun according to any one of claims 1 to 3, wherein the repulsion electrode is formed into a cylindrical shape via a mesh-shaped conductive material. The electron gun according to any one of claims 1 to 3, wherein the repulsion electrode is configured such that an inner circumferential surface is located at a side surface of the same cylindrical shape. A vacuum processing apparatus, comprising: a vacuum chamber; and the electron gun according to any one of the first to third aspects of the invention, wherein the inside of the vacuum chamber and the inside of the electron gun are In the vacuum chamber, an object to be irradiated is disposed in the vacuum chamber, and the object to be irradiated is irradiated with the electron beam emitted from the discharge port.