JPH05263241A - Ion treating device - Google Patents

Abstract

PURPOSE:To surely and easily replace a filament whose service life has expired without opening a vacuum treatment chamber in the atmosphere by equipping both the holding part of the filament and an electrode on the holding part of a base plate and taking out the filament to the outside of a device. CONSTITUTION:A susceptor 2 fitted with a filament and a base plate is arranged in a housing part. The susceptor 2 carried from the housing part is fitted to the holder 1 of the base plate. The base plate is irradiated with ion beams 5 in an ion chamber 9. Further, the filament is energized and thermions are discharged to perform ion treatment. After the ion treatment is finished, the susceptor 2 is carried out to the outside of an ion treating device and the residual service life of the filament on the susceptor 2 is investigated. When the service life has expired, the filament is replaced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion processing apparatus for irradiating a substrate with an ion beam for processing, and more particularly to a load lock type ion processing apparatus suitable for long-term continuous operation.

[0002]

2. Description of the Related Art A conventional ion treatment apparatus is disclosed, for example, in Hitachi Review Vol. 6 (1986-6) P49-P52
As described in "Development of large-diameter ion beam milling apparatus", a filament is provided between the ion source and the substrate holder. This filament emits thermoelectrons when energized, and serves as a neutralization mechanism for neutralizing the charge-up of the substrate due to the irradiation of the ion beam.

The neutralization mechanism using this filament is
It has a simple structure, yet is highly effective in neutralization, and is an effective means. However, since the life of filament is generally about several tens of hours, it is necessary to replace it before its life. When replacing the filament, the process is temporarily stopped, the vacuum of the device is released to the atmosphere, and the filament is fixed to the filament attachment part of the device. The need to change filaments is very commonly used in batch-type devices because it is inexpensive and reliable.

[0004]

However, the fact that it is necessary to replace the filament every several tens of hours is a fatal drawback in a load lock structure device capable of continuously processing a plurality of substrates. .. By using a cassette-cassette system or the like, the load-lock structure device can continuously process a plurality of substrates without opening the processing chamber even once. However, it is necessary to open the vacuum processing chamber to the atmosphere in order to replace the filament. This means that the processing efficiency is extremely lowered due to the interruption of the processing and the processing performance due to the processing chamber being opened to the atmosphere. Cause instability. For this reason, efforts have been made to extend the life of the filament and to provide another electron beam source, but there are problems in reliability and price.

The present invention compensates for the drawbacks of the conventional apparatus and provides an ion processing apparatus equipped with a neutralizing mechanism which is inexpensive and has high reliability because it is not necessary to open the vacuum processing chamber to the atmosphere for filament replacement. To do.

[0006]

In order to solve the above-mentioned problems, according to the present invention, a vacuum container and the inside of the vacuum container,
An ion processing apparatus comprising: an ion source for irradiating an ion beam; a substrate holding unit for holding a substrate; a filament holding unit for holding a filament that emits thermoelectrons; and an electrode for passing a current through the filament. An ion treatment apparatus is provided, in which the filament holder and the electrode are provided in the substrate holder.

[0007]

In the ion treatment apparatus of the present invention, the ion source irradiates the substrate held by the substrate holder with the ion beam to perform the ion treatment. The filament holder holds the filament. When a current is supplied from the electrode to the filament during the ion treatment, the filament emits thermoelectrons. The thermoelectrons neutralize the substrate charged up by the ion treatment.

In the present invention, the substrate holding portion is provided with the filament holding portion and the electrode. Therefore, the filament can be taken out of the device together with at least the portion of the substrate holding portion where the filament holding portion is arranged. Usually, when the substrate is replaced with the next substrate, the substrate is taken out while being held by a part of the substrate holding unit. At this time, therefore, the filament holding unit and the filament provided in the substrate holding unit are taken out of the apparatus. .. Outside the apparatus, the life of the filament can be checked every time the substrate is replaced, and the expired filament can be reliably and easily replaced.

A technique for taking out a substrate in an ion processing apparatus to the outside without releasing the vacuum is already widely known. For example, an apparatus having a load-lock structure using a cassette-cassette system can continuously perform ion treatment on a plurality of substrates without releasing the vacuum and take them out to the outside. In such a device, when the present invention is used, each of the substrate holding portions that hold the substrate in a transportable manner,
By attaching the filament holder and the electrode, the processing efficiency can be improved. In such an apparatus, a plurality of substrates are successively subjected to the ion treatment one after another, and the treated substrate is taken out to check the life of the filament and replace it.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

In this embodiment, the present invention is applied to a cassette-cassette type milling device. As shown in FIG. 1, the milling apparatus of this embodiment is composed of three chambers, a cassette chamber 7, a transfer chamber 8 and an ion processing chamber 9. Gate valves 11a, 11 that can be opened and closed between the rooms
b is arranged. An exhaust pump 12a is provided in the transfer chamber 8.
However, an exhaust pump 12b is attached to each of the ion processing chambers 9. A gate valve 11c that can be opened and closed is provided between the transfer chamber 8 and the exhaust pump 12a.
A gate valve 11d that can be opened and closed is disposed between the exhaust valve 12b and the exhaust pump 12b.

A bucket type ion source 4 is attached to the ion processing chamber. Further, inside the ion processing chamber 4, a substrate holder 1 for removably fixing the susceptor 2 is arranged. The substrate holder 1 is attached to a rotation mechanism 13 that rotatably fixes the substrate holder.

The susceptor 2 can be transferred among the cassette chamber 7, the transfer chamber 8 and the processing chamber 9 while holding the substrate 20. A neutralizer (that is, a neutralization mechanism) 3 is attached to the susceptor 2. The susceptor 2 and the substrate holder 1 form a substrate holding portion that holds the substrate 20.

A transfer robot 10 is arranged in the transfer chamber 8. Further, cassette holders 6a and 6b are arranged in the cassette chamber 7. Cassette holder 6a,
6b, cassettes 36a, 36b capable of accommodating a plurality of susceptors 2 holding the substrate 20 are set. A door 70 is provided in the cassette chamber, and the door is opened to set the cassettes 36a and 36b in the cassette holders 6a and 6b.

The substrate holder 1, the susceptor 2, and the neutralizer 3 will be described in more detail with reference to FIGS. 2, 3 and 4. As shown in FIG. 3, the susceptor 2 has a ring shape, and has a step portion 2d on the inner wall at a position 2c from the back side of the susceptor 2. The diameter of the inner wall opening 2a of the ring on the back side of the susceptor 2 is equal to that of the circular substrate 2 to be held.
It is slightly larger than the diameter of 0. The depth 2c is equal to the thickness of the substrate 20. Further, beyond the depth 2c, a diameter 2b smaller than the diameter of the substrate 20 is formed to form a step 2d, and an opening having a diameter 2b is formed on the side of the susceptor 2 that receives the ion beam 5. The substrate 20 is set in the through hole from the back surface side of the susceptor 2 and held by the step portion 2d.

Further, the susceptor 2 has a pair of small through holes 2m and 2n. In these through holes 2m and 2n,
Metal terminal bars 19m and 19n are inserted,
Both ends thereof are projected on the back surface side of the susceptor 2 and the side receiving the ion beam. Terminal bar 19m, 19n
The end on the side of receiving the ion beam has a holding mechanism for holding the filament. Further, the end portion on the back side also serves as an electrode for passing a current through the filament. Insulators 18m and 18n are arranged between the terminal rods 19m and 19n and the susceptor 2. Insulator 18m, 18
n insulates the terminal rods 19m and 19n from the susceptor 2.

The structure of the tip ends of the terminal rods 19m and 19n on the side of the ion treatment surface will be further described with reference to FIG. A male screw is cut from the tip to the position k from the terminal rod 19n. Further, at a position about k from the tip, the washer 22n
Is fixed. The terminal bar 19n has the X shown in FIG.
A through hole 24n is formed in the direction. Filament 2
3 is passed through this through hole 24n. When the nut 21n is tightened from the tip of the terminal rod 19n, the filament 23 is sandwiched and fixed between the nut 21n and the washer 22n. Since the terminal rod 19m has the same structure, its explanation is omitted.

The substrate holder 1 has a cooling holder 15
And a ring-shaped crimping plate 17. Crimping plate 1
7, the crimping plate 17 is pressed against the cooling holder 15,
A pair of drive rods 16m and 16n are attached for moving away the pressure plate 17 that has been pressed. The cooling holder 15 includes drive rods 16m and 16n.
Drive rod recesses 26m and 26n are formed for fitting with. Gears 25m and 25n for driving the drive rod are provided on the inner wall portions of the drive rod recesses 26m and 26n.
Are arranged. The drive rods 16m and 16n and the gears 25m and 25n have a rack and pinion configuration. The gears 25m and 25n are rotated by a motor (not shown) to drive the driving lots 16m and 16n to push the pressing plate 17 against the cooling holder or move it away from the cooling holder.

A step portion 27 is formed on the inner wall of the ring-shaped crimping plate 17. The crimping plate 17 holds the susceptor 2 at the step 27.

The cooling holder 15 further has a pair of terminal rod recesses 26m and 26n for fitting with the rear projections of the terminal rods 19m and 19n of the susceptor 2. Inside the recesses 26m, 26n for terminal rods, the ends of the lead wires 29m, 29n for passing a current through the terminal rods are exposed. The lead wires 29m and 29n are insulated from the cooling holder 15 by the insulator 14. Lead wire 2
9m and 29n are electrically connected to a power source (not shown). When the susceptor 2 is held on the crimping plate 17 and pressed against the cooling holder 15, the terminal rods 19m and 19n are fitted into the terminal rod recesses 26m and 26n, and the terminal rods 19m and 19n are engaged.
When the lead wires 29m and 29n come into contact with each other, a current flows through the filament 23 via the terminal rods 19m and 19n.

Next, the operation of the ion milling device of this embodiment will be described. The user attaches a plurality of substrates 20 to each other.
Each of them is set in the susceptor 2 to which the neutralizer 3 is attached, is housed in a cassette 36a, and set in the cassette holder 6a above the cassette chamber 6. Next, the exhaust pumps 12a and 12b are operated to evacuate the transfer chamber 8 and the ion processing chamber 9, respectively. The cassette chamber 7 is evacuated to a vacuum by the exhaust pump 12a with the gate valve 11a opened. After the cassette chamber 7 is evacuated, the gate valve 11a is closed to isolate each chamber.

Next, the gate valve 11a is opened, and the transfer robot 10 takes out one susceptor 2 holding the substrate 20 from the cassette 36a and transfers it to the transfer chamber 8. Next, the gate valve 11b is opened to hold the substrate, and the susceptor 2 is held.
Are transferred to the processing chamber 9 and set on the pressure bonding plate 17 of the substrate holder 1. The gate locks 11a and 11b are opened only during transportation, and closed at other times. Each chamber is isolated and vacuum is maintained except when the substrate 20 is being transported.

Next, a gear 25 is driven by a motor (not shown).
m and 25n are driven to draw the drive rods 16m and 16n into the drive rod recesses 26m and 26n, and the crimp plate 17 is pressed against the cooling holder 15. As a result, the terminal rod 19
m and 19n fit into the terminal rod recesses 28m and 28n, electrically contact the lead wires 29m and 29n, and a current flows through the filament 23. Further, the substrate 20 housed in the susceptor 2 comes into close contact with the cooling holder 15 and is cooled. Further, the substrate holder 1 fixes the susceptor 2 holding the substrate 20, so that the substrate 20 faces the ion source 4.

The ion source 4 has an ion beam 5 on a substrate 20.
And ion treatment. The filament 23 is energized to emit thermoelectrons and neutralize the substrate charged up by the irradiation of the ion beam 5.

When the ion treatment is completed, the gears 25m, 2
5n is driven in the opposite direction, the driving rods 16m and 16n are extended, and the pressure bonding plate 17 is moved away from the cooling holder 15.
The transfer robot 10 removes the ion-processed substrate 20 together with the susceptor 2 from the pressure bonding plate 17 and transfers the ion-processed substrate 9 to the cassette chamber 7 in the reverse order of the above-described procedure. Then, the cassette 36b on the lower side of the cassette chamber 7
Then, the susceptor 2 and the substrate 20 are housed.

The transfer robot 10 uses the next substrate 10
Are taken out from the upper cassette 36a. Then, the same procedure as above is repeated to perform the ion treatment, and the ion treatment is performed, and the cassette 36b on the lower side is accommodated. This is the upper cassette 3
All the substrates accommodated in 6a are subjected to ion treatment, and the process is continued until accommodated in the lower cassette 36b.

During this ion treatment,
A neutralizer 3 is attached to each of a plurality of other susceptors 2 outside the milling device. Then, a plurality of new substrates 20 to be subjected to ion treatment are respectively attached to the susceptor 2
And set in another cassette 36c.

After all the substrates 20 are processed, only the cassette chamber 7 is returned to atmospheric pressure with the gate valve 11a closed, and the door 70 is opened. The empty cassette 36a is taken out from the cassette holder 6a. The cassette holder 6a includes a cassette 3 containing a substrate to be ion-processed.
Set 6c. Next, from the cassette holder 6b,
The cassette 36b containing the ion-processed substrate 20 is taken out, and an empty cassette 36a is set instead.

The gate valves 11a and 11c are opened, and the inside of the cassette chamber 7 is evacuated to a vacuum. Then, the substrates 20 accommodated in the cassette 36c are sequentially subjected to ion treatment, and the treated substrates 20 are accommodated in the cassette 36a.

Outside the milling apparatus, the susceptor 2 and the ion-treated substrate 20 housed in the cassette 36b taken out are taken out. Then, the remaining life of the filament 23 of the neutralizer 3 of each susceptor 2 is checked. The life is checked by energizing the filament, measuring the magnitude of the current value, and estimating the remaining life from this magnitude. When the current value is below a predetermined constant value, it is replaced with a new filament. To replace, loosen the nuts 21m and 21n of the neutralizer 3 and remove
This is done by replacing with a new filament 23.

As described above, in the milling apparatus of this embodiment, the terminal rods 19 that also serve as filament holding portions and electrodes are arranged on the susceptors that are part of the substrate holding portion. Therefore, for some reason, even if the filament 23 of one susceptor is cut, only the substrate 20 held by the susceptor is not neutralized, and the other substrates 20 are affected. Absent.

The filament of the neutralizer 3 attached to each susceptor is taken out of the milling device together with the substrate 20. During this time, the ion treatment is continued on the substrate 20 held by another susceptor. Outside the apparatus, the life of the filament 23 of the neutralizer 3 attached to the taken-out susceptor 2 is checked, and the filament having a short remaining life is replaced. Therefore, it is not necessary to interrupt the ion processing or open the processing chamber 9 to the atmosphere for filament replacement, and it is possible to perform a continuous continuous operation for a dramatically long period of time. It can be carried out.

If the filament 23 is replaced before the end of its life, there is usually no concern that it will be cut during the process, but if it should be cut for any reason, it will be opened to the atmosphere while continuing ion processing with another neutralizer. Instead, it can be taken out and replaced, so that for a neutralizer, the life can be virtually infinite.

The neutralizer 3 of the milling apparatus of this embodiment has an extremely simple structure in which each susceptor 2 has a filament holding portion for holding the filament 23 and an electrode. Therefore, even if each susceptor is arranged, it can be realized at low cost.

Further, in the milling device of this embodiment, since the filament 23 is replaced outside the device, the filament 23 can be replaced more easily and surely than in the conventional device having a small opening.

In the above-mentioned embodiment, the terminal rods 19m and 19n which also serve as the electrode and the filament holding portion are arranged, but the present invention is not limited to this, and the electrode and the holding portion are separately provided. It may be provided in. Further, as the means for holding the filament, the means for tightening with the nut and washer was used in the present embodiment, but the terminal rods 19m, 19n
A slit can be formed at the tip of the wire, and a means for sandwiching the filament in the slit can be used, or a means for forming a constriction at the tip of the terminal rod and winding the filament around the constriction to hold it can be used. ..

Further, in the present embodiment, an example in which the present invention is applied to a milling apparatus has been described, but it goes without saying that it can also be applied to an ion beam sputtering apparatus, an ion implantation processing apparatus and the like.

[0038]

According to the present invention, there is no need to open the ion treatment chamber to replace the filament of the neutralization mechanism, and an ion treatment apparatus equipped with an inexpensive and highly reliable neutralization mechanism is provided. Provided.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a cassette-cassette type milling device showing an embodiment of the present invention.

FIG. 2 is a cutaway sectional view showing a configuration near a substrate holding portion of the apparatus of FIG.

3 is a cross-sectional view showing the configurations of a pressure plate 17 and a susceptor 2 of FIG.

FIG. 4 is a cross-sectional view showing the structure of a portion of the terminal rod 19n shown in FIG. 3 for holding a filament.

[Explanation of symbols]

1 ... Substrate holder, 2 ... Susceptor, 3 ... Neutralizer, 4 ... Ion source, 5 ... Ion beam, 6 ... Cassette holder, 7 ... Cassette chamber, 8 ... Transport chamber, 9 ... Ion processing chamber, 10 ... Transport robot, 11a to 11d ... Gate valve,
12a, b ... Exhaust pump, 13 ... Substrate holder rotation mechanism section, 15 ... Cooling holder, 16m, 16n ... Driving rod,
17 ... Crimping plate, 18m, 18n ... Insulator, 19m, 19
n ... terminal rod, 20 ... substrate, 25m, 25n ... gear, 26
m, 26n ... Recess for drive rod, 27 ... Step, 28m,
28n ... recess for terminal rod, 29m, 29n ... lead wire, 2
1m, 21n ... Nut, 22m, 22n ... Washer.

Claims (14)

[Claims] 1. A vacuum vessel, an ion source for irradiating an ion beam in the vacuum vessel, a substrate holding section for holding a substrate, a filament holding section for holding a filament emitting thermoelectrons, and the filament. An ion treatment apparatus having an electrode for passing an electric current, wherein the filament holder and the electrode are provided in the substrate holder. 2. An ion processing apparatus comprising a vacuum container, an ion source for irradiating an ion beam, a substrate holding portion for holding a substrate, and a thermoelectron emitting means for emitting electrons in the vacuum container. The ion processing apparatus, wherein the thermoelectron emission means is provided in the substrate holding part. 3. The ion processing apparatus according to claim 1, wherein the filament holding unit positions the filament to be held on a side of the substrate holding unit which is irradiated with the ion beam. 4. The substrate holding unit according to claim 1 or 2, wherein the substrate holding unit includes a susceptor and a substrate holder, and the susceptor includes the filament holding unit and is conveyed while holding the substrate. The ion processing apparatus is characterized in that the substrate holder holds the susceptor detachably, and the substrate faces the ion source. 5. The electrode according to claim 4, wherein the electrode is disposed on the susceptor, the substrate holder has a power supply line for supplying a current to the electrode, and the substrate holder holds the susceptor. The electric wire is in electrical contact with the electrode. 6. The susceptor storage unit for storing a plurality of the susceptors according to claim 4, and a transfer unit for transferring the susceptor from the susceptor storage unit to the substrate holder. Ion processing equipment. 7. The ion processing apparatus according to claim 6, wherein each of the plurality of susceptors has the filament holding portion and the electrode. 8. The vacuum container according to claim 6, wherein the vacuum container has an ion processing chamber and a preliminary vacuum chamber which are separated by a valve that can be opened and closed, and the ion source and the substrate holder are arranged in the ion processing chamber. Further, the susceptor storage part is disposed in the preliminary vacuum chamber, and the transfer means transfers the susceptor when the valve is opened. 9. The ion processing apparatus according to claim 6, wherein the preliminary vacuum chamber has an openable / closable door portion for taking out the susceptor to the outside. 10. The filament holding part according to claim 1, wherein the filament holding part is made of a conductor, and has a holding mechanism part for holding a filament on one end side and an electrode connected to the power supply line on the multi-end side. Ion processing device. 11. The substrate according to claim 5, wherein the electrode has a protrusion protruding from the susceptor, and the substrate holder has a recess in which a part of the power supply line is exposed on an inner wall. When the holder holds the susceptor, the protrusion and the recess are fitted to each other so that the power supply line comes into contact with the electrode. 12. A neutralization device for emitting thermoelectrons to the substrate, which is arranged in an ion processing apparatus having a vacuum container, an ion source in the vacuum container, and a substrate holding unit for holding the substrate. The mechanical section has a filament holding section for holding a filament that emits thermoelectrons, and an electrode for passing a current through the filament, and the filament holding section and the electrode are provided in the substrate holding section. The neutralization mechanism part of the ion treatment device, which is characterized in that 13. The method of operating an ion treatment apparatus according to claim 6, wherein a susceptor having a filament and a substrate attached thereto is arranged in a storage unit in advance, and the susceptor is transported from the storage unit to a substrate holder, Is attached to a substrate holder, the substrate is irradiated with an ion beam, and the filament is energized to emit thermoelectrons for ion treatment, and after the ion treatment is completed, the susceptor is carried out of the ion treatment apparatus. And a method for operating an ion treatment device. 14. The method for operating an ion treatment apparatus according to claim 13, further comprising examining the remaining life of the filament of the susceptor carried out, and replacing the filament when the remaining life is equal to or less than a predetermined constant value.