JP4002958B2 - Neutralizer - Google Patents

Description

  The present invention relates to a neutralizer that is a mechanism for emitting thermoelectrons from a filament to which a voltage is applied.

  Ion Assist Deposition (hereinafter referred to as “Ion Assist Deposition”) is a technique for forming dense thin films with strong adhesion by ionizing the gas introduced into the vacuum chamber and pressing the deposited molecules against the substrate with the generated cations. Called IAD.)

FIG. 6 is a schematic view of a vacuum deposition apparatus for optical thin films using the IAD method, and the outline of thin film formation in the apparatus shown in FIG.
An exhaust system including a main pump 32, a main valve 34, a roughing pump 33, a roughing valve 35, an auxiliary valve 36, and the like is attached to the main body of the vacuum chamber 30 for vacuum exhaust. Inside the vacuum chamber body 30, a substrate 41, a substrate dome 42 for mounting the substrate 41, a substrate heating heater 43 for heating the substrate 41, a vapor deposition material 39, a crucible 38 for depositing the vapor deposition material 39, and the vapor deposition material 39 at an evaporation temperature An electron gun 40 that heats up to, a shutter 37 that closes when the vapor deposition is completed and shields the vapor deposition material 39, an ion source 31 that emits ions for assisting, a neutralizer 46 that emits electrons to the substrate dome 42, etc. A substrate dome rotation mechanism 44 and various power sources (not shown) are disposed outside the vacuum chamber.

Since IAD normally assists vapor deposition molecules with positively charged cations, cations accumulate on the substrate or the substrate dome on which the substrate is mounted, and the entire substrate dome is charged with a positive charge. This phenomenon is called charge-up.
When the charge-up occurs, dielectric breakdown occurs between the substrate dome and other components having the ground potential, and arc discharge occurs. In addition, since the entire substrate dome has a positive charge, the cation does not move toward the substrate dome and the assist effect is weakened.

FIG. 7 is a schematic diagram for explaining the state of the substrate dome 42 before the charge-up, and FIG. 8 is the charge-up.
As shown in FIG. 7, when the substrate dome 42 is not charged up, the vapor deposition molecules 50 are assisted by the cations 51 and jump into the substrate dome 42 to form a dense thin film. Become. However, when the substrate dome 42 is charged up as shown in FIG. 8, the potential difference between the substrate dome 42 and the cation 51 decreases, and the assist effect is weakened. Further, arc discharge 52 is generated between the substrate dome 42 and the other components 53.

  The neutralizer 46 is a mechanism that discharges electrons having a negative charge toward the substrate dome 42 in order to prevent the substrate dome 42 from being charged up, and performs electrical neutralization on the substrate dome 42. It is disclosed in Japanese Patent Application Laid-Open No. H10-228707 and the like relating to an element film forming apparatus.

  Since the neutralizer mechanism is a mechanism for emitting electrons, it also serves as a trigger for generating plasma by accelerating the ionization by colliding the accelerated electrons with the gas introduced into the vacuum chamber.

FIG. 9 shows a schematic cross-sectional view of a conventional neutralizer 46.
The neutralizer shown in the figure includes a filament 60 that emits thermoelectrons, an electrode 61 that applies an acceleration voltage to the filament 60 to pass a filament current, a filament presser 62 that fixes the filament 60 to the electrode 61, an electrode 61 and the filament A screw 63 for fastening the presser 62, a base 64 for attaching the electrode 61, an interelectrode insulator 65 for insulating the electrode 61, a base insulator 66 for insulating the electrode 61 and the base 64, a cap 67 for covering the electrode 61 and the filament 60. , And has an anode cap 68 that covers the cap 67 and draws thermal electrons emitted from the filament 60.

  The configuration is such that wiring from an external power source of the vacuum chamber is connected to the electrode 61, an acceleration voltage is applied to the filament 60 fixed to the electrode 61, a current flows through the filament, and thermoelectrons are emitted from the filament 60. . The anode cap 68 and the base 64 are grounded, and the electrons emitted from the filament 60 are drawn out to the anode cap 68 that is at the ground potential and irradiated toward the substrate dome 42. Of course, a positive potential may be applied to the anode cap 68.

  The cap 67 and the electrode 61, the anode cap 68 and the base 64 are finely threaded with each other, and have a structure for screwing. Other components are fixed with screws.

When vapor deposition is performed using the apparatus shown in FIG. 6, first, a substrate 41 for vapor deposition is installed on the substrate dome 42. Then, the vapor deposition material 39 is put into the crucible 38. Then, after evacuating the inside of the vacuum chamber to a pressure of about several Pa using the roughing pump 33 and the roughing valve 35, the main pump 32, the main valve 34, the auxiliary valve 36, and the like are used to evacuate to a high vacuum. After the vacuum chamber is in a vacuum state, the substrate 41 is heated using the substrate heater 43 while rotating the substrate dome 42 by the substrate dome rotation mechanism 44. When the degree of vacuum and the substrate temperature reach the target values, the electron gun 40 irradiates the deposition material 39 with an electron beam, and raises the deposition material 39 to the evaporation temperature. Further, ions are irradiated using an ion source (ion gun) 31. The ionization means is not limited to an ion source. For example, a high frequency voltage (hereinafter referred to as RF) is applied to the substrate dome, or an RF is applied to the antenna by introducing an antenna to generate plasma in the vacuum chamber. What is necessary is just to select suitably, such as generating and ionizing. When the shutter 37 is opened, the vapor deposition material 39 scatters in the vacuum chamber and is assisted by ions to be deposited on the substrate 42 to form a dense thin film. At the same time, electrons are emitted from the neutralizer 46 toward the substrate. When the film thickness reaches the target value, the shutter 37 is closed, the electron gun 40, the neutralizer 46, the substrate heating heater 43, the ion source 31 and the like are stopped, and after cooling, the atmosphere is introduced into the vacuum chamber and a thin film is formed. Take out the processed substrate.
JP 2004-131783 A

Since the neutralizer is a mechanism that emits thermoelectrons from a filament that generates heat by resistance heating, the filament and the electrode rise to a high temperature when energized.
In the conventional neutralizer mechanism, the electrode is fixed on the insulator with screws for the purpose of insulation, but due to the difference in thermal expansion coefficient between the electrode and the insulator, the electrode expands greatly compared to the insulator when energized, There has been a problem that the insulator is distorted or damaged.
For example, when stainless steel SUS304 is used as the electrode material and alumina insulator is used as the insulator material, the coefficient of linear expansion of stainless steel SUS304 is approximately 17.3E-6, and the coefficient of linear expansion of the alumina insulator is approximately 7.0E. Therefore, when a current is passed through the filament and the temperature in the unit rises to several hundred degrees Celsius, the stainless steel expands much more than the insulator due to the difference in linear expansion coefficient. At this time, since the interelectrode insulator is sandwiched between the electrodes and securely fixed with screws, distortion or breakage occurs during thermal expansion. Further, since the base insulator is also fixed to the inside of the base with a screw, distortion and breakage occur as in the case of thermal expansion.

  Also, the conventional neutralizer mechanism removes the anode cap and cap, loosens the filament mounting screw, and replaces the filament. However, the anode cap and cap are screwed with fine screws, so the neutralizer is used. When residual heat remains in the rear body, there is a problem that galling or the like occurs in the fine screw. In addition, if the filament mounting screws are not tightened evenly, the filament retainer may be damaged, the filament mounting bolt may be galled, or loosened due to heating when the filament is energized. There was also a problem that would occur.

  Furthermore, when it is necessary to use two filaments in the conventional neutralizer mechanism, it is necessary to mount two sets of the entire neutralizer mechanism shown in FIG. 9, resulting in a doubled number of parts, and vacuum. There was also a problem of expansion of the occupied area inside the tank and an increase in cost.

  An object of the present invention is to provide a neutralizer that is free from distortion and breakage even when an electrode is thermally expanded with a low-cost and high-maintenance configuration.

  A first aspect of the present invention is a neutralizer having a filament, a pair of electrodes for passing a current through the filament, and a base for supporting the pair of electrodes in an insulated state, and the relative position between the pair of electrodes and the base is It is a neutralizer having holding means for holding in a state that can be changed in at least one direction. Here, one direction was defined as a direction perpendicular to the inter-electrode distance direction of the pair of electrodes. Further, the holding means includes a fixing means and a positioning means. The fixing means fixes a pair of electrodes to the base at least one place for each electrode, and the positioning means positions the pair of electrodes to the base at at least one place for each electrode. In addition, the relative position between the pair of electrodes and the base can be changed in at least one direction. The fixing means includes a first insertion fixture made of bolts or screws, and the positioning means includes a pair of first holes provided in the pair of electrodes, a pair of second holes provided in the base, and at least It consists of the 2nd penetration fixture which penetrates the 1st hole, and has the shape from which the shape of the 1st or 2nd hole differs from the peripheral side shape of the 2nd penetration fixture, and the 1st or 2nd The area of the hole was made larger than the cross-sectional area cut by the base surface of the second insertion fixture. Still further, the first or second hole has a substantially elliptical shape having a long radius in a direction perpendicular to the inter-electrode distance direction of the pair of electrodes or an elliptical shape extending in the direction. The base is made of insulators at least at the fixed part with the electrodes.

  According to a second aspect of the present invention, the neutralizer according to the first aspect further includes a filament presser for fixing the filament to the electrode, and a cross section in the direction of the distance between the pair of electrodes of each electrode opens upward. The filament retainer has a shape that fits into the chip, the filament retainer is fixed to the electrode with a third insertion fixture, and the end of the filament is supported by the fitting portion. It is a thing. Furthermore, the shape of the chip was made substantially trapezoidal. The third insertion fixture was a bolt.

  According to a third aspect of the present invention, in the neutralizer according to the first or second aspect, a plurality of filaments are fixed to an electrode.

  According to a fourth aspect of the present invention, the neutralizer according to any one of the first to third aspects includes an anode plate that extracts electrons emitted from the filament, and a side plate that covers the side surfaces of the filament and the electrode. It is set as the structure fixed to the upper surface of a side plate with a 4th insertion fixing tool. Further, the fourth insertion fixture is a bolt.

  According to the fifth aspect of the present invention, in the neutralizer according to any one of the first to fourth aspects, all the insertion fixtures used are inserted in the same direction.

  A sixth aspect of the present invention is a neutralizer having a filament, a pair of electrodes for applying a voltage to pass a current through the filament, and an electrode for supporting the pair of electrodes in an insulated state and a base having a different coefficient of thermal expansion. In this method, the electrodes are fixed to the base, and the pair of electrodes and the base are fixed in a state where the relative position can be changed in at least one direction. Further, the one direction is a direction perpendicular to the inter-electrode distance direction of the pair of electrodes.

  The seventh aspect of the present invention is a method for assembling or disassembling any of the first to fifth aspects of the neutralizer by inserting all of the insertion fixtures used in only one direction.

  The neutralizer of the present invention proposes a design that prevents distortion or breakage caused by thermal expansion while reducing the number of parts, thereby contributing to longer life and cost reduction. In addition, it is effective in improving maintainability and preventing individual differences in assembly and adjustment by the operator.

  FIG. 1 is an external view of an embodiment of the present invention, and FIG. Hereinafter, the neutralizer according to the present invention is mounted on a vacuum apparatus similar to the apparatus shown in FIG. 6, and the operation thereof is the same as that of the prior art, so that the description thereof is omitted, but the apparatus capable of implementing the present invention. Is not limited to this.

  The neutralizer shown in FIGS. 1 and 2 includes a filament 1, an electrode 2 that applies an acceleration voltage to pass a current through the filament 1, a crimp terminal 10 that connects wiring from an external power supply to the electrode 2, and an electrode 2. Filament presser 3 for fixing filament 1, screw 4 for fastening electrode 2 and filament presser 3, base insulator 7 for attaching electrode 2, neutralizer case 12 for covering electrode 2 and filament 1, heat released from filament 1 An anode plate 11 for extracting electrons;

  The anode plate 11 is fixed to the anode support 6 by mounting screws 13. The neutralizer case 12 is disposed on the neutralizer base 5 and is sandwiched between the anode plate 11 and has a structure that does not fall off. In the embodiment, considering the workability and cost, the anode plate 11, the neutralizer case 12, and the anode support 6 are all bolted separately, but it is also possible to integrate them all into a box shape. .

  The embodiment employs a structure in which the plate-shaped anode is screwed without using the cap-shaped anode 68 that is screwed by the fine screw, so that the galling due to heating is suppressed as much as possible. In addition, the conventional structure that has been double-covered by the cap 67 and the anode cap 68 is changed to a single cover, which contributes to simplification of the configuration and improvement in maintainability.

  The electrode 2 is fixed on a base insulator 7 fixed on the neutralizer base 5 with screws by being insulated from the neutralizer base 5 by positioning pins 8 and countersunk screws 9. In the embodiment, the base insulator 7 is made of an insulator, but a base having at least a contact surface with the electrode 2 made of an insulating material may be used.

  FIG. 3 shows a detailed view of the positioning pin 8. The hole 80 for the positioning pin 8 provided in the electrode 2 has a substantially elliptical shape having a major radius in a direction perpendicular to the inter-electrode distance direction, and the minor radius of the substantial ellipse is only slightly larger than the diameter of the pin 8. And In addition, this substantially elliptical shape is a concept including an ellipse obtained by extending a circle in one direction. Thereby, the direction of arrow C shown in FIG. 3 and the direction of arrow B shown in FIG. 2 are maintained, and the distance between the electrodes is reliably maintained. Therefore, since the structure does not require the interelectrode insulator 65 as in the conventional type shown in FIG. 9, there is no possibility that the interelectrode insulator is damaged.

  Due to the shape of the hole 80 for the positioning pin 8, the electrode 2 can be thermally expanded only in the direction A shown in FIG. Since the electrode is not fixed with screws at both ends as in the prior art, but one side is fixed with the positioning pin 8, the electrode 2 can be thermally expanded even if the filament 1 is heated by energization, which is impossible for the base insulator 7. It is possible to remarkably reduce the possibility that the base insulator 7 is damaged without applying force.

  In the figure, the hole 80 is substantially oval or oval. However, the shape of the hole 80 has a degree of freedom of movement of the positioning pin 8 in a direction (longitudinal direction) perpendicular to the inter-electrode distance direction of the electrode 2. Other shapes may be used as long as the movable range is limited in the inter-distance direction. Further, in this embodiment, the positioning pin 8 has a circular cross section. However, if the position can be determined, the fragment does not have to be circular. For example, a polygonal shape or other cross sectional shape may be used. Good. Further, according to this, the shape of the hole 80 may correspond to the cross-sectional shape of the positioning pin 8.

  Further, the hole having the shape as described above may be provided in the base insulator 7 instead of the electrode 2 or in both the electrode 2 and the base insulator 7. When the hole is provided only in the base insulator 7, the positioning pin 8 may penetrate the base insulator 7, or the end of the positioning pin 8 may be positioned in the base insulator 7. When the positioning pin 8 passes through the base insulator 7, it is necessary to insulate the positioning pin 8 and insulate the neutralizer base 5 and the positioning pin 8 from each other. Further, when holes are provided in both the electrode 2 and the base insulator 7, the positioning pins 8 are fixed to the neutralizer base 5, so that it is necessary to insulate the positioning pins 8 as described above. In addition, the electrode 2 and the base insulator 7 may be fixed by the positioning pins 8 at all locations. In this case, however, the position of the electrode 2 is freely movable with respect to the base insulator 7. A method of accurately positioning the plate with the countersunk bolt 9 is adopted.

  In the embodiment, the number of insulators that could be damaged is reduced to one, and the electrode and the insulator are not fixed with screws. However, it was possible to prevent distortion and breakage without applying excessive force to Choshi.

The attachment of the filament will be described with reference to FIG.
The filament 1 is fixed to the electrode 2 by a filament presser 3 and a filament mounting screw 4, and a voltage is applied to the filament 1 from a power source outside the vacuum chamber via the crimping terminal 10 and the electrode 2. The filament retainer 3 is constituted by a block having a substantially trapezoidal cross section, and is fixed to the electrode 2 by tightening in a direction indicated by an arrow D shown in FIG. Due to the substantially trapezoidal block, a force acts on the filament 1 in the direction of arrow E shown in FIG. 4, and the filament 1 can be reliably fixed. Moreover, it becomes possible to fix a some filament simultaneously and reliably by making the cross section of the filament retainer 3 into a substantially trapezoidal block.
In the embodiment, the cross-sectional shape of the filament retainer 3 is a trapezoid opening upward, but if the pressure is applied to the side surface of the filament retainer 3 by pressing downward, for example, a polygon opened upward, etc. Other cross-sectional shapes can be used.

  In the embodiment, by adopting a structure in which a plurality of filaments are mounted in one unit, it is possible to add filaments without adding a unit as in the past, and the number of parts can be greatly reduced. It was. The number of filaments mounted in one unit may be selected as appropriate, and of course, one filament may be mounted in one unit. In this case, the size may be reduced by the same mechanism as in the embodiment. Further, since the filament can be used regardless of the shape, a desired shape may be appropriately selected.

  In the embodiment, the shape of the filament presser 3 is a substantially trapezoidal block, and the structure in which the filament 1 can be securely fixed by screwing from the upper surface is adopted, thereby reducing individual differences in the filament mounting position and height.

  Further, the structure in which the filament retainer 3 is screwed from the upper surface and the plate-shaped anode 11 is screwed from the upper surface make it possible to unify the screwing directions of the attachment parts. In the embodiment, since a structure in which all the parts to be attached and detached at the time of filament replacement and maintenance are screwed from the upper surface is adopted, workability and maintainability can be remarkably improved.

Another embodiment of the present invention is shown in FIG.
In the embodiment shown in FIG. 2, in order to obtain a movable range of the electrode during thermal expansion, a long hole is provided in the electrode 2 and the positioning pin 8 is attached to the insulator 7. However, the neutralizer shown in FIG. 20 is divided, one of the divided levers is screwed onto the neutralizer base 5, and the other lever is machined with a long hole and fixed with a positioning pin 21. If the electrode is fixed on the divided insulator 20 with a bolt 22, a movable range at the time of thermal expansion can be provided as in the embodiment shown in FIG.

  Although the neutralizer used in the IAD method has been described above, the present invention is not limited to the above embodiment as long as it is a mechanism that emits thermoelectrons from a filament.

External view of neutralizer mechanism of the present invention Schematic view of the neutralizer mechanism of the present invention Detailed positioning pin Filament mounting schematic Schematic of another embodiment of the present invention Schematic diagram of vacuum deposition equipment for optical thin films Explanation of board dome charge-up 1 Explanation of board dome charge-up 2 Schematic cross section of conventional neutralizer

Explanation of symbols

1 Filament
2 electrodes
3 Filament presser
4 screws
5 Neutralizer base
6 Anode support
7 Base eggplant
8 Positioning pin
9 countersunk screws
10 Crimp terminal
11 Anode plate
12 Neutralizer case
13 screw
20 base eggplant
21 Positioning pin
22 screw
30 Vacuum chamber body
31 Ion source
32 Main pump
33 Roughing pump
34 Main valve
35 Roughing valve
36 Auxiliary valve
37 Shutter
38 Crucible
39 Vapor deposition materials
40 electron gun
41 Board
42 PCB dome
43 Heater for substrate heating
44 Substrate dome rotation mechanism
50 Vapor deposited molecules
51 cation
52 Arc discharge
53 Other components
80 holes

Claims (10)

A neutralizer having a filament, a pair of electrodes for passing a current through the filament, and a base for supporting the pair of electrodes in an insulating state;
The relative position and the pair of electrodes and said base have a holding means for holding at a variable ready at least one direction,
The one direction is a direction perpendicular to the inter-electrode distance direction of the pair of electrodes,
The holding means fixes the pair of electrodes to the base at least one location for each electrode, and the pins for positioning the pair of electrodes relative to the base at least one location for each electrode and the pins Consisting of positioning means consisting of holes into which
The holes are provided in the pair of electrodes or the base, and the holes extend in the one direction so that the relative movement direction of the holes with respect to the pins is regulated in the one direction. A neutralizer having a width substantially equal to the width of the pin .
The neutralizer according to claim 1 ,
The neutralizer, wherein the first or second hole has a substantially elliptical shape having a major radius in a direction perpendicular to the inter-electrode distance direction of the pair of electrodes or an elliptical shape extending in the direction. .
The neutralizer according to claim 1 or 2 ,
A neutralizer characterized in that an insulator is integrally formed on the base and the hole is formed in the electrode or the insulator, and the electrode is slidably held with respect to the insulator .
The neutralizer according to claim 1 or 2,
A neutralizer characterized in that an insulator is integrally formed on the electrode, the hole is provided in the base or the insulator, and the insulator is slidably held with respect to the base.
The neutralizer according to any one of claims 1 to 4 , wherein
Furthermore, it has a filament presser for fixing the filament to the electrode,
A cross-section in the distance direction between the pair of electrodes of each of the electrodes has a chip with a shape that opens upward;
The filament retainer has a shape that fits into the chip,
The filament presser is fixed to the electrode with a first insertion fixture,
A neutralizer, wherein the end of the filament is supported by the fitting portion.
6. The neutralizer according to claim 5 , wherein the shape of the chip is substantially trapezoidal.
The neutralizer according to any one of claims 1 to 6 ,
A neutralizer, wherein a plurality of filaments are fixed to the electrode.
A neutralizer according to any one of claims 5 to 7 ,
An anode plate that draws electrons emitted from the filament, and a side plate that covers side surfaces of the filament and the electrode;
A neutralizer, wherein the anode plate is fixed to the upper surface of the side plate by a second insertion fixture.
The neutralizer according to claim 8 , wherein
The fixing means comprises an insertion fixture;
The neutralizer , wherein the fixing means, the pin, and the first and second insertion fixtures are inserted in the same direction.
A neutralizer having a pair of electrodes for passing a current through a filament and a base having a different coefficient of thermal expansion from that of the electrodes for supporting the pair of electrodes in an insulated state, and fixing the pair of electrodes to the base. ,
Fixing the pair of electrodes to the base by fixing means at least one location for each electrode; and
A step of positioning the pair of electrodes by a positioning means so as to be slidable in one direction with respect to the base at at least one position for each of the electrodes;
Consists of
The one direction is a direction perpendicular to the inter-electrode distance direction of the pair of electrodes,
The positioning means includes a pin and a hole provided in the pair of electrodes or the base, and the positioning step includes a step of inserting the pin into the hole, and the relative movement direction of the hole with respect to the pin is the one direction. The hole has a shape extending in the one direction so as to be regulated in a direction, and the width of the hole is substantially equal to the width of the pin .

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