JP2002302764A - Sputtering apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To considerably reduce a time and a cost required for a dummy etching after exchanging a deposition-preventive shield in a pre-etching chamber. SOLUTION: Deposition-preventive shields 261-264 for preventing deposition of a material emitted from a substrate 9 are disposed in an exchangeable manner in the pre-etching chamber 2 which is connected to a sputter chamber 4 for performing the deposition by the sputtering so as to ensure the continuous vacuum and performs the pre-etching of the surface of the substrate 9 therein. A moving mechanism 29 moves a plate 91 to be etched which is formed of the same material as that emitted from the substrate 9 and thicker than the substrate 9 between the evacuation position in an evacuation chamber 28 adjacent to the pre-etching chamber 2 so as to be communicated with the inner space and the same position as the position of the substrate 9 during the pre- etching. The inside of the evacuation chamber 28 is evacuated by an exhaust system 21 for common use.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus for forming a thin film on a surface of a substrate by sputtering, and more particularly to a sputtering apparatus for performing a pretreatment for etching the surface of a substrate prior to film formation. is there.

[0002]

2. Description of the Related Art Sputtering apparatuses are widely used in various industrial fields as apparatuses for forming a thin film on the surface of a substrate. In particular, in the manufacture of various electronic devices such as LSIs, a sputtering apparatus is often used for forming various conductive films and insulating films. In such a film forming technique, a pre-treatment (hereinafter, referred to as pre-treatment etching) for etching the surface of the substrate may be performed before the film formation.
The pretreatment etching is a treatment for removing a thin film formed on the surface of a substrate in many cases.

For example, a natural oxide film or a protective film may be formed on the surface of a substrate. If the film forming process is performed in a state where such a thin film is formed, the quality of the formed thin film may be deteriorated. For example, when a conductive material for wiring is formed in a state in which an insulating natural oxide film or a protective film is formed on the surface of the substrate, the conductivity between the surface of the underlying substrate and the conductive film for wiring is formed. There is a problem that becomes worse.

When a film is formed in the presence of a natural oxide film and a protective film, the adhesion of the thin film to the substrate may be deteriorated. Further, even when dust or dirt is attached to the surface of the substrate, the adhesion of the thin film to the substrate, the conductivity, and the like are deteriorated. Therefore, prior to film formation,
The surface of the substrate is etched to remove a natural oxide film, a protective film, or foreign matter such as dust on the surface.

[0005] Pretreatment etching is usually performed in a chamber provided separately from a sputtering chamber for performing sputtering. It is not impossible to perform pretreatment etching in the sputter chamber, but if pretreatment etching is performed in the sputter chamber, fine particles of the natural oxide film and protective film released during the pretreatment etching pass through the sputter chamber. The substrate is liable to be contaminated such as floating and being mixed in a thin film formed at the time of sputtering.

On the other hand, in the case of a substrate processing apparatus such as a sputtering apparatus, there is a demand for an improvement in processing quality due to the background of miniaturization and high integration of devices, and the processing becomes complicated due to the sophistication of devices. Due to this tendency, a multi-chamber type device in which a plurality of vacuum chambers are airtightly connected has become mainstream. The same applies to the above-described sputtering apparatus for performing the pre-processing etching, and a plurality of vacuum chambers including a pre-processing etching chamber and a sputtering chamber in which the pre-processing etching is performed are hermetically connected. The substrate is sent from the pre-processing etching chamber to the sputtering chamber without being taken out to the atmosphere, and the pre-processing etching and sputtering are continuously performed in a vacuum.

Therefore, the structure for the pre-processing etching includes a pre-processing etching chamber and members provided inside and outside thereof. Hereinafter, this configuration is referred to as a pretreatment etching module. The pre-treatment etching module usually employs a configuration for performing sputter etching. That is, a plasma is formed by high-frequency discharge in the pre-treatment etching chamber, and ions in the plasma are incident on the surface of the substrate.

In such a pretreatment etching module, an anti-adhesion shield is provided to prevent the material released from the surface of the substrate during the etching from adhering to a specific place. The deposition shield has a shape surrounding a space where plasma is formed. Without the deposition shield, fine particles such as a natural oxide film and a protective film that are etched and released from the substrate during the pre-processing etching adhere to the exposed surface such as the wall surface of the pre-processing etching chamber. When the adhesion of the fine particles to the exposed surface overlaps, the fine particles grow over time, and the thin film may peel off due to internal stress or own weight. The peeled thin film becomes particles as described above,
This may cause the substrate to be soiled. In this specification, the term particle is used as a general term for fine particles (atoms, molecules, particles, fragments, etc.) that contaminate a substrate. Irregularities are formed on the surface of the deposition shield to prevent the deposited thin film from peeling off. The deposition shield is replaceably provided, and after a predetermined number of pretreatment etchings, the shield is replaced with a new one or a thin film from which the thin film has been removed.

[0009]

In the above-described sputtering apparatus, after processing a predetermined number of substrates, the inside of the apparatus is returned to the atmospheric pressure, and a periodic maintenance operation is performed. In particular, for the pre-process etching module, one of the main tasks is to replace the above-described deposition shield. When the regular maintenance is completed, the inside of the apparatus is evacuated to a predetermined vacuum pressure, and then the film forming process is restarted.

However, for the pre-treatment etching chamber, the treatment cannot be resumed immediately after the regular maintenance is completed. More specifically, if the pre-etching is restarted immediately after evacuation to a predetermined vacuum pressure after regular maintenance, abnormal discharge such as arc discharge occurs, a large amount of particles are generated suddenly, or etching occurs. Distribution (distribution of etching rate in the plane of the substrate)
May be uneven. That is, generally speaking, since reproducibility cannot be sufficiently ensured, pre-processing etching cannot be resumed as it is.

The reason why reproducibility cannot be ensured is that the state in the pretreatment etching chamber is different from that before the regular maintenance. Specifically, before the periodic maintenance, a thin film such as an oxide is deposited on the surface of the deposition shield, but no thin film is deposited on the surface of the replaced deposition shield. Deposition shields are often made of metal such as stainless steel or aluminum, but the conditions differ greatly when a thin film made of an insulator is deposited and when the surface of the metal member is exposed as it is. . For example, when a high-frequency electric field is set for plasma formation, if the material of the surface of the member in the pre-processing etching chamber is different, the state of the electric field is considered to be different.

Therefore, in the pre-treatment etching chamber, an operation is performed after the regular maintenance to make the same condition as before the regular maintenance. Specifically, the dummy substrate is etched, and an oxide thin film is deposited on the surface of the deposition shield (hereinafter, this etching is referred to as dummy etching). The dummy substrate has, for example, a structure in which an oxide layer having a predetermined thickness is formed on the surface of bare silicon by thermal oxidation. By performing the dummy etching a certain number of times, a thin oxide film is deposited to a certain thickness on the surface of the deposition shield. After repeating the dummy etching to such an extent that reproducibility can be ensured, normal pre-processing etching is restarted.

However, in order to ensure sufficient reproducibility and restart the pretreatment etching, it is necessary to repeat a considerable number of dummy etchings. For example, a diameter of 300
In the case of an apparatus for processing a silicon wafer having a thickness of 2 mm, the dummy etching needs to be repeated about 100 times, so that the number of dummy substrates required for the apparatus is about 100. The total time required for dummy etching is 3
It reaches as much as an hour.

The fact that a long time is required for the dummy etching means that the time required for resuming the pretreatment etching is lengthened, which is a factor that greatly reduces the productivity. Also,
The necessity of a large number of dummy substrates means an increase in running costs, and this problem is serious because the cost of the substrates increases. The invention of the present application has been made to solve such a problem, and has the technical significance of greatly reducing the time and cost required for dummy etching after replacement of the deposition shield in the pretreatment etching chamber.

[0015]

In order to solve the above-mentioned problems, the invention according to claim 1 of the present application provides a sputtering chamber in which a film forming process for forming a thin film on a surface of a substrate by sputtering is performed, A sputtering apparatus including a pretreatment etching chamber provided in such a manner that a pretreatment for etching the surface of the substrate is performed internally and a sputter chamber and a vacuum are connected to each other prior to the treatment, wherein the inside of the pretreatment etching chamber is Has an exchangeable shield for preventing the material released from the surface of the substrate during the etching from adhering to a specific place, so that the pre-processing etching chamber communicates with the internal space. An evacuation chamber provided adjacent to the substrate, and a material released from the surface of the substrate during the pretreatment etching. A plate to be etched, which is a plate material formed of the same material as the above, and is thicker than the substrate. It has a configuration in which a moving mechanism that moves the plate to be etched between the position where the substrate is arranged during the pre-processing etching and the same position, and a dual or dedicated exhaust system that exhausts the evacuation chamber are provided. . According to a second aspect of the present invention, in order to solve the above-mentioned problem, in the configuration of the first aspect, the plate to be etched has the same dimensions and shape as the substrate except for the thickness.

[0016]

Embodiments of the present invention (hereinafter, embodiments) will be described below. FIG. 1 is a schematic plan view of a sputtering apparatus according to an embodiment of the present invention. The sputtering apparatus shown in FIG. 1 is a multi-chamber type apparatus, and a transfer chamber 1 arranged at the center.
And a plurality of processing chambers 2, 3, 4 and two load lock chambers 5 provided around the transfer chamber 1. Each of the chambers 1, 2, 3, 4, and 5 has a dedicated or combined exhaust system (not shown), and is evacuated to a predetermined pressure. A gate valve 6 is provided at a connection point between the chambers 1, 2, 3, 4, and 5.

An autoloader 7 is provided outside the load lock chamber 5. The autoloader 7 takes out the substrates 9 one by one from the external cassette 8 on the atmosphere side and stores the substrates 9 in the internal cassette 51 in the load lock chamber 5. A transfer robot 11 is provided in the transfer chamber 1. The transfer robot 11 is an articulated robot. The transfer robot 11 takes out the substrates 9 one by one from one of the load lock chambers 5 and sends them to each of the processing chambers 2, 3, and 4 to sequentially perform the processing. It returns to the load lock chamber 5. A vacuum pressure of about 10 ⁻⁴ to 10 ⁻⁶ Pa is constantly maintained in the transfer chamber 1 by an exhaust system (not shown). Therefore, a transfer robot that can operate under this vacuum pressure is adopted.

One of the plurality of processing chambers 2, 3, 4 is a sputtering chamber 4 for performing sputtering for forming a predetermined thin film on the surface of the substrate 9. The other one of the processing chambers 2 constitutes a pre-processing etching module which is a major feature of the present embodiment. Still another processing chamber 3 is a preheat chamber 3 for preheating the substrate 9 before sputtering.

Next, the configuration of the pretreatment etching module, which is a major feature of the apparatus of the present embodiment, will be described with reference to FIG. FIG. 2 is a schematic front sectional view of a pretreatment etching module included in the apparatus shown in FIG.

The pretreatment etching module includes a pretreatment etching chamber 2 in which pretreatment etching is performed, an exhaust system 21 for exhausting the inside of the pretreatment etching chamber 2, and a gas for introducing a gas into the pretreatment etching chamber 2. Introducing system 22 and substrate holder 23 for holding substrate 9 at a predetermined position in pretreatment etching chamber 2
A plasma forming means for forming plasma in a space facing the surface of the substrate 9 held by the substrate holder 23; and a bias power supply 24 for setting an electric field for extracting ions from the formed plasma and causing the ions to enter the surface of the substrate 9. It is mainly composed of

The pre-treatment etching chamber 2 is an airtight vacuum container, and the substrate 9 is taken in and out through a gate valve 6. The exhaust system 21 is configured to ^supply 10 ⁻⁵ to 10 ⁻⁷ Pa in the pretreatment etching chamber 2.
It is configured to be able to exhaust to the extent. Gas introduction system 2
2 is designed to introduce an inert gas such as argon at a predetermined flow rate. The gas introduction system 22 stores a predetermined amount of gas in the gas reservoir 221, and introduces the gas in the gas reservoir 221 into the pretreatment etching chamber 2 by opening and closing the valve 222.

The substrate holder 23 is a pedestal-like member for placing and holding a substrate on the upper surface. The substrate holder 23 includes a metal holder body 231, a quartz glass plate 232 fixed on the holder body 231, and a holder body 23.
1 mainly comprising a support 233 for supporting the support 1. The quartz glass plate 232 is provided in consideration of the possibility that the surface of the substrate holder 23 may be etched during the pre-processing etching, and the quartz glass plate 232 is provided so as not to generate a polluting substance even when etched. ing. The substrate holder 23 has an insulating cover 234 so as to surround the periphery. The insulating cover 234 is for preventing unnecessary discharge around the substrate holder 23.

The substrate holder 23 has an elevating mechanism 235 that is driven when taking the substrate 9 in and out. When the substrate 9 is taken in and out, the elevating mechanism 235 moves the substrate holder 23.
Is positioned at a predetermined lower limit position, and is positioned at an upper limit position as shown in FIG. 2 during pre-processing etching. The substrate holder 23 goes up and down while airtightly penetrating the bottom plate portion of the pretreatment etching chamber 2, and a vacuum seal 236 such as a mechanical seal is provided in the penetrating portion.

In this embodiment, plasma for pre-processing etching is formed by high-frequency discharge.
That is, the plasma forming means includes a high-frequency electrode provided in the pretreatment etching chamber 2 and a high-frequency power supply for plasma 25 for applying a high-frequency voltage to the high-frequency electrode. In the present embodiment, the high frequency power supply for plasma 25 is a VHF band (30 MHz to 300 MHz) such as 60 MHz.
Those that generate the high frequency of z) are used.

In the present embodiment, the substrate holder 23 is also used as a high-frequency electrode. That is, the plasma high-frequency power supply 25 includes the holder main body 231 and the quartz glass plate 23.
A high-frequency voltage is applied to the substrate 9 via the second circuit 2. The power supply for bias 24 is similarly connected to the holder main body 23.
A high-frequency voltage is applied to the substrate 9 via the first and quartz glass 232. That is, the bias power supply 24 and the plasma high-frequency power supply 25 are connected to the holder body 231 in parallel. Note that the bias power supply 24 and the plasma high-frequency power supply 25 are connected to the holder main body 231 via a matching device (not shown).

As the bias power supply 24, one that generates a high frequency in the MF band (300 to 3000 kHz) such as 400 kHz is used. When the bias power supply 24 operates in a state in which the plasma of the gas introduced by the gas introduction system 22 is formed by the plasma high-frequency power supply, electrons and ions in the plasma are removed from the plasma power supply 2.
5 is periodically attracted to the substrate 9 with a period longer than the high frequency. At this time, due to the difference in mobility between the electrons and the ions, the electrons are attracted more than the ions, and when integrated over time, the change in the potential of the substrate 9 is as if a negative DC voltage was superimposed on the high frequency of the bias power supply. (Actually, the potential change by the high frequency power supply for plasma is superimposed on this). This negative DC voltage is the self-bias voltage.
Positive ions are extracted by the self-bias voltage and efficiently incident on the surface of the substrate 9 to sputter-etch the surface of the substrate 9.

As shown in FIG. 2, a magnet 27 is provided above the pretreatment etching chamber 2. The magnet 27 prevents the diffusion of the plasma toward the upper wall of the pretreatment etching chamber 2.

In such a pretreatment etching module, as described above, the deposition shields 261, 262, 263 and 263 prevent the material released from the surface of the substrate 9 during etching from adhering to a specific place. 264 are provided. Deposition shields 261, 262, 263, 26
4 is a lower shield 261 that surrounds the substrate 9 on the substrate holder 23, and a lower shield 2
Upper shield 2 in a state of closing the upper opening of 61
62 and the outer shield 2 in a state of closing the gap 260 between the lower shield 261 and the upper shield 262.
63 and a fixing shield 264 for fixing the outer shield 263 to the lower shield 261 and the upper shield 262.

A large amount of substances discharged during the pre-treatment etching adhere to the deposition shields 261, 262, 263, 264.
Reference numeral 64 denotes a configuration in which the thin film is prevented from peeling by providing fine irregularities on the surface. The irregularities are formed by a blast method which is a method of spraying a granular material such as sand. Deposition shields 261, 262, 263, 264
After a certain number of repetitions of the pretreatment etching, is replaced with a new one or a thin film from which the thin film has been removed.

The lower shield 261 and the upper shield 262 are cylindrical with the same diameter. The lower shield 261 has an opening, through which the substrate holder 23 is inserted. The gap 260 is provided to improve the conductance of the internal space formed by the lower shield 261 and the upper shield 262 and the like. External shield 2
An opening / closing mechanism (not shown) is attached to 63, and when the inside of the pre-treatment etching chamber 2 is evacuated, the outer shield 263 moves to open the gap 260. Note that these shields 261, 262, 26
All 3,264 are electrically grounded.

The major feature of this embodiment is that a dedicated member used for dummy etching after replacement of the shield is previously disposed in the apparatus. More specifically, in the present embodiment, dummy etching is performed by etching a member 91 that is formed of the same material as the material released from the surface of the substrate 9 during pre-processing etching and that is thicker than the substrate 9. It is supposed to do. Hereinafter, this plate material 91 is referred to as a plate to be etched.

In this embodiment, the substrate 9 is a silicon wafer, and the pre-processing etching removes a natural oxide film on the surface of the silicon wafer. Therefore, the plate 91 to be etched is a plate made of silicon oxide, specifically, a quartz glass plate. Plate 91 to be etched
Has the same shape and dimensions as the substrate 9 except for the thickness. The thickness is larger than the substrate 9 and is about 5 mm to 10 mm. still,
When a plate 91 having the same shape and dimensions as the substrate 9 is used, a state close to the state of the pre-processing etching can be reproduced, which is suitable for enhancing the effect of the dummy etching.

In this embodiment, the plate 9 to be etched is
A dedicated evacuation chamber 28 is provided to reduce the time required for moving 1. The evacuation chamber 28
As shown in FIG. 2, it is an airtight container provided adjacent to the pretreatment etching chamber 2. Evacuation chamber 2
Reference numeral 8 denotes a pretreatment etching chamber 2 in the present embodiment.
Exhaust chamber 21 is a space for uniformly and efficiently exhausting air.
0 is also used. Specifically,
The evacuation chamber 28 includes the pre-treatment etching chamber 2
Is provided adjacent to the side wall of the main body. The side wall of the pre-treatment etching chamber 2 has an opening corresponding to the size of the evacuation chamber 28, and the evacuation chamber 28 is connected so as to airtightly close this opening. A shutoff valve 282 is provided at a connection point of the evacuation chamber 28.

An opening is formed in the bottom wall of the evacuation chamber 28, and a vacuum pump 211 constituting the exhaust system 21 is provided below the opening. The vacuum pump 211 evacuates the opening of the bottom wall of the evacuation chamber 28 to evacuate the evacuation chamber 28 and the pretreatment etching chamber 2. Between the vacuum pump 211 and the evacuation chamber 28, an exhaust speed controller (not shown) may be provided.

As shown in FIG. 2, an anchor 281 is provided in the evacuation chamber 28. Mooring device 2
Numeral 81 is a member for mounting and mooring the plate to be etched 91 for evacuation. Therefore, the position on the mooring tool 281 is the retracted position of the plate to be etched 91. Then, a moving mechanism 29 for moving the plate to be etched 91 between the retracted position and a predetermined position in the pre-processing etching chamber 2 is provided. The predetermined position in the pretreatment etching chamber 2 is the same position as the position where the substrate 9 is located at the time of the pretreatment etching, and is on the substrate holder 23.

FIG. 3 is a schematic plan view of a main part of the moving mechanism 29 shown in FIG. In the present embodiment, a simple single-arm type robot is adopted as the moving mechanism 29. That is, the moving mechanism 29 includes an arm 291 for mounting and holding the substrate 9, a vertical drive rod 292 having the upper end connected to the arm 291, and the arm 291 via the drive rod 292.
And a driving source 293 for driving the. The drive source 293 allows the arm 291 to perform expansion and contraction movement in a horizontal plane, rotation movement around the drive rod 292 as a central axis, and up and down movement via the drive rod 292.

Next, another configuration of the sputtering apparatus of this embodiment will be described. The preheating (preheating) in the preheating chamber 3 is performed for the purpose of releasing the occluded gas of the substrate 9. If the occlusion gas is not released, there is a problem that the occlusion gas is released due to heat during film formation and the surface of the film becomes rough due to foaming. In the preheat chamber 3, a heat stage (not shown) that is heated and maintained at a predetermined temperature is provided. The substrate 9 is placed on this heat stage and is preheated by being heated to a predetermined temperature. In order to improve the thermal conductivity between the heat stage and the substrate 9, a gas having good thermal conductivity such as He may be supplied between the heat stage and the substrate 9.

The sputter chamber constitutes a sputtering module which is a module for performing sputtering. The sputtering module has a sputtering chamber, an exhaust system for exhausting the sputtering chamber,
A gas introduction system for introducing a gas such as argon into the sputtering chamber, a cathode including a target provided such that a surface to be sputtered is exposed in the sputtering chamber, and a voltage for sputtering the target is applied to the cathode. It comprises a sputtering power source, a substrate holder for holding the substrate 9 at a position in the sputtering chamber facing the target, and the like.

A sputter power supply is operated while a gas such as argon is introduced by a gas introduction system and the inside of the sputtering chamber is maintained at a predetermined vacuum pressure by an exhaust system.
A sputter discharge occurs to sputter the target, and a thin film of the target material is formed on the surface of the substrate 9. Behind the target (on the side opposite to the surface to be sputtered), a magnet unit that enables magnetron sputtering is provided.

As shown in FIG. 1, a further vacuum chamber 1 is provided around the separation chamber 1.
0 is provided. These vacuum chambers 10
If necessary, the same configuration as that of the sputtering chamber 4 may be used to improve the productivity, or when laminating different kinds of thin films, the sputtering chamber 4 may be provided with a target made of a different material. Alternatively, after the film forming process, the cooling chamber for cooling the substrate 9 may be used.

Next, the overall operation of the sputtering apparatus of this embodiment will be described. The substrate 9 accommodated in the external set 8 is carried into the internal cassette 51 in the load lock chamber 5 by the autoloader 7. The substrate 9 carried into the internal cassette 51 is first carried into the pre-processing etching chamber 2 by the transfer robot 11 provided in the separation chamber 1, and the above-described pre-processing etching is performed. At this time, the to-be-etched plate 91 is at the retreat position in the retreat chamber 28. Further, when exhausting the pre-treatment etching chamber 2, the shut-off valve 2
Although the opening 82 is opened, the shut-off valve 282 is closed when performing the pre-processing etching, so that the inside of the pre-processing etching chamber 2 and the inside of the evacuation chamber 28 are isolated. Therefore, the plate to be etched 91 is not etched.

After the completion of the pretreatment etching, the substrate 9 is transported to the preheat chamber 3, is placed on a heat stage (not shown), and is heated to a predetermined temperature. Thus, the substrate 9 is preheated, and the occluded gas in the substrate 9 is released. Then, the substrate 9 is carried into the sputtering chamber 4, and a film forming process by sputtering is performed. Thereafter, the substrate 9 is unloaded from the sputtering chamber 4 by the transfer robot 11 and stored in the internal cassette 51.
The processed substrate 9 stored in the internal cassette 51 is stored in the external cassette 8 by the autoloader 7. By repeating such an operation, a large number of substrates 9 are sequentially
Perform single wafer processing.

After repeating such a single-wafer processing a predetermined number of times, maintenance of the apparatus is performed. Maintenance is performed by the deposition shield 2 in the pretreatment etching chamber 2 described above.
61, 262, 263, and 264 are included. That is, after replacing the deposition shields 261, 262, 263, and 264, a predetermined number of dummy etchings are performed.

More specifically, the inside of the apparatus is returned to the atmospheric pressure, and necessary operations such as replacement of the deposition shields 261, 262, 263, 264 are performed. After that, the inside of the pretreatment etching chamber 2 is again evacuated to 10 ⁻⁵ to 10 by the exhaust system 21.
^It is evacuated to a vacuum of about ^-7 Pa. And shut-off valve 2
The opening 82 is opened and the moving mechanism 29 is operated to place the plate to be etched 91 on the substrate holder 23. The mounting position is the same position as in the case of the substrate 9. As in the case of receiving the substrate 9, the lifting mechanism 235 moves the substrate holder 23.
Is lowered, and after the plate to be etched 91 is placed, the substrate holder 23 is raised to the same height as in the case of the pre-processing etching.

Then, a gas is introduced into the pretreatment etching chamber 2 by the gas introduction system 22, and plasma is formed under the same conditions as in the pretreatment etching to perform dummy etching. The etching time in the dummy etching is longer than the time required for pre-processing etching of one substrate 9. Specifically, the dummy etching is performed for a time corresponding to the number of times the dummy etching is repeated in the conventional configuration. Specifically, it is about 5 minutes to 10 minutes.

After the dummy etching once but for a long time, the shut-off valve 282 is opened and the inside of the pre-treatment etching chamber 2 is evacuated again by the exhaust system. Then, the ordinary dummy substrate is carried into the pre-processing etching chamber 2, and the dummy etching is performed under exactly the same conditions as the normal pre-processing etching. After confirming that reproducibility is obtained, the ordinary pre-processing etching is performed. It is assumed that resumption is OK. In addition, after performing the work necessary for restarting the apparatus, the normal film forming processing for sequentially performing the above-described pretreatment etching, degassing, and sputtering is restarted.

In the apparatus according to the present embodiment having the above-described structure and operation, the dummy etching is performed using the plate 91 to be etched, so that the running cost is significantly reduced as compared with the case where the conventional dummy substrate is used. Become cheap. More specifically, as described above, for example, in a conventional apparatus, about 100 dummy substrates are required for dummy etching in one regular maintenance. According to the apparatus of the present embodiment, one etching target plate 91 is sufficient. The cost of one plate to be etched 91 is about 1/40 of the cost of 100 dummy substrates, and the effect of running cost reduction is remarkable. In addition, one plate 91 to be etched can be used for dummy etching at the time of a plurality of regular maintenances, so that the running cost can be further reduced.

Further, in the conventional dummy etching, it is necessary to carry the dummy substrate into the pretreatment etching chamber 2 from the atmosphere side similarly to the normal substrate 9, and to carry it out to the atmosphere side after one dummy etching. there were. Such a transport operation has to be performed for the number of times of necessary dummy etching (for example, 100 times), which leads to prolongation of the entire time required for dummy etching.

On the other hand, in the present embodiment, the plate 91 to be etched is stored in the evacuation chamber 28 adjacent to the pre-processing etching chamber 2, and only the substrate 91 is moved between the pre-processing etching chamber 2 and the evacuation chamber 28. So the time required is much shorter. In addition, in the dummy etching in one regular maintenance, the carry-in and carry-out of the to-be-etched plate 91 may be performed only once, and need not be repeated many times as in the related art. Therefore, in this respect, the required time is much shorter. For this reason, according to the present embodiment, the entire time required for dummy etching is significantly reduced, and productivity is significantly improved.

In the above-described example, the dummy etching is performed once for a long time. However, in order to approach the condition of the pre-processing etching more closely, one dummy etching is performed at the same time of the pre-processing etching. It may be repeated the required number of times. In this case, the to-be-etched plate 91 may be left on the substrate holder 23 as it is, and the effect of shortening the time required for transport can be similarly obtained.

The configuration in which the plate to be etched 91 is always stored in the evacuation chamber 28 has an effect that pollutants in the atmosphere are not taken into the apparatus through the plate to be etched 91. If the dummy substrate is taken in and out from the atmosphere side as in the related art, the pollutants in the atmosphere are easily brought into the apparatus by attaching to the dummy substrate. According to the present embodiment, there is no such a problem since the etching target plate 91 is located in the evacuation chamber 28 exhausted by the exhaust system 21. The plate to be etched 9
1 may be made of a material other than quartz. For example, when the pre-processing etching is to remove the nitride film on the surface of the substrate 9, the etching target plate 91 made of a nitride such as silicon nitride may be used.

The moving mechanism 29 may employ a configuration in which the robot is moved linearly, such as a slide mechanism, in addition to the configuration using the robot described above. Further, the configuration is not limited to the configuration in which the evacuation chamber 28 is also used for the exhaust chamber 210, and the evacuation chamber 28 may be provided separately from the exhaust chamber 210. In this case, a dedicated exhaust system may be provided in the evacuation chamber 28.

In the above embodiment, the substrate holder 23
Is also used as a high-frequency electrode for plasma formation, but a dedicated high-frequency electrode may be provided separately. For example, another high-frequency electrode is provided so as to form a parallel plate electrode together with the substrate holder 23. The layout of the chamber is not limited to the cluster tool type shown in FIG. 1, but may be an in-line type.

[0054]

As described above, according to the first aspect of the present invention, dummy etching can be performed using a plate to be etched which is made of a material released from the substrate in the pre-processing etching and which is a thicker plate than the substrate. As a result, the running cost is much lower than in the past. In addition, the plate to be etched is stored in the evacuation chamber adjacent to the pre-processing etching chamber, and only the plate to be etched needs to be moved between the evacuation chamber and the pre-processing etching chamber. Becomes shorter. For this reason, productivity is also significantly increased.
According to the second aspect of the present invention, in addition to the above-described effects, since a plate to be etched having the same shape and dimensions as the substrate except for the thickness is used, it is possible to reproduce a state close to the state of pre-processing etching The effect of the dummy etching can be enhanced.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a sputtering apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic front sectional view of a pretreatment etching module included in the apparatus shown in FIG.

3 is a schematic plan view of a main part of a moving mechanism 29 shown in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transfer chamber 2 pretreatment etching chamber 21 exhaust system 210 evacuation room 211 vacuum pump 22 gas introduction system 23 substrate holder 24 bias power supply 25 plasma high-frequency power supply 261 deposition shield 262 deposition shield 263 deposition deposition shield 264 deposition deposition shield 28 Evacuation chamber 281 Mooring tool 282 Shut-off valve 29 Moving mechanism 3 Preheat chamber 4 Sputter chamber 9 Substrate 91 Plate to be etched

Continued on the front page F term (reference) 4K029 FA04 KA01 5F004 AA14 AA15 BB32 BC06 BD05 DB00 5F103 AA08 BB36 BB49 PP01 PP06

Claims (2)

[Claims] 1. A sputter chamber in which a film forming process for forming a thin film on a surface of a substrate by sputtering is performed internally, and a pre-process in which a surface of the substrate is etched prior to the film forming process is performed inside the sputtering chamber. A pretreatment etching chamber provided so as to be continuous, wherein the material released from the surface of the substrate during etching adheres to a specific place in the pretreatment etching chamber. An anti-adhesion shield is provided so as to be replaceable, an evacuation chamber provided adjacently so that the pre-processing etching chamber and the internal space communicate with each other, and a substrate at the time of the pre-processing etching. A plate material formed of the same material as the material emitted from the surface, and a plate to be etched that is thicker than the substrate, When performing dummy etching to ensure reproducibility after replacing the shield, the plate to be etched is etched between a predetermined retreat position in the retreat chamber and the same position where the substrate is placed during the pre-processing etching. A sputtering apparatus, comprising: a moving mechanism for moving a plate; and a dual or dedicated exhaust system for exhausting the evacuation chamber. 2. The sputtering apparatus according to claim 1, wherein the plate to be etched has the same dimensions and shape as the substrate except for the thickness.