JP2001335927A - Sputtering system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sputtering system effectively suppressing the generation of particles and keeping uniformity in film deposited on a substrate without any problem in the production, and in which, after exchanging the stick- preventive shields, film deposition is pre-formed where thin films are deposited on the stick-preventive shields. SOLUTION: After exchanging the stick-preventive shields 481, 482 and 483 and a target 41, the inside of a sputtering chamber 4 is exhausted by an exhaust system 46, thereafter, a dummy substrate 91 which has been retreated to a retreating chamber 40 in the sputtering chamber 4 is moved to the substrate holding face of a substrate holder 44 by a moving mechanism 40 for dummies, and the substrate holding face is covered. Then, a sputter power source 43 is activated to generate sputter discharge and to sputter the target 41. Then film deposition is preformed where thin films are thinly deposited on the surfaces of the sticking preventive shields 481, 482 and 483.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus used for manufacturing an LSI (Large Scale Integrated Circuit) or the like.

[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 an object. 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.

FIG. 7 is a sectional view showing a schematic configuration of a conventional sputtering apparatus. The device shown in FIG.
6, a gas introduction system 45 for introducing a predetermined gas into the sputtering chamber 4, a target 41 provided so that a surface to be sputtered is exposed in the sputtering chamber 4, and a target 41. A sputter power source 43 for generating a sputter discharge by setting an electric field in a space facing the surface to be sputtered, and a substrate for holding the substrate 9 at a predetermined position in the sputter chamber 4 where sputter particles emitted from the target 41 by the sputter discharge reach. It is mainly composed of a holder 44.

In the above-described apparatus, it is inevitable that sputtered particles emitted from the target 41 deposit a thin film not only on the surface of the substrate 9 but also on an exposed surface in the sputter chamber 4. If the deposition of the thin film on the exposed surface overlaps, the thin film may be peeled off due to internal stress or own weight.
The peeled thin film becomes fine particles of a certain size and floats in the elementary sputtering chamber 4. When the fine particles adhere to the substrate 9, a shape defect such as formation of minute projections on the formed thin film may occur. Further, when a fine circuit is formed on the surface of the substrate 9 in advance, there is a possibility that a serious defect such as a disconnection or a short circuit of the circuit may occur due to the adhesion of the fine particles.

The fine particles that impair the quality of such treatment are:
Generally called "particles". In order to prevent the generation of particles, a member called a deposition prevention shield is usually provided in the sputtering chamber 4. The deposition prevention shield prevents sputtered particles from attaching to unnecessary places other than the surface of the substrate 9. Although it is inevitable that sputtered particles adhere to the deposition shield to deposit a thin film, the deposition shield is configured to prevent peeling of the thin film by forming fine irregularities on the surface. Nevertheless, if the sputtering is repeated many times, peeling of the thin film is inevitable. Therefore, after a predetermined number of sputterings, the shield is replaced with a new shield or a shield from which the thin film has been removed.

In the apparatus shown in FIG. 7, a plurality of deposition shields having different shapes and arrangement positions are used. First, a substantially cylindrical deposition shield 481 surrounding the space between the target 41 and the substrate holder 44 is provided (hereinafter, this deposition shield is referred to as a main shield). Further, another deposition shield 482 is attached to the substrate holder 44 so as to surround the substrate holding surface of the substrate holder 44 (hereinafter, this deposition shield is referred to as a holder shield). Further, a ring-shaped deposition shield 48 is provided so as to surround the periphery of the substrate 9 held by the substrate holder 44.
3 (hereinafter, this deposition shield is called a ring shield).

[0007] In the above-described apparatus, it is necessary to perform regular maintenance after repeating a predetermined number of times of sputtering. The main work in the periodic maintenance is replacement of the target 41 and the shields 481, 482, 483.
In sputtering, a film is formed by cutting the target 41, so that the target 41 is consumed as the sputtering is repeated. Therefore, it is necessary to replace a new one after repeating a predetermined number of times.

The periodic maintenance is performed by opening the inside of the sputtering chamber 4 to the atmosphere. After performing operations such as replacement of the target 41 and the deposition shields 481, 482, 483, the inside of the sputtering chamber 4 is evacuated to a high vacuum by the exhaust system 46. However, in this state, sputtering cannot be restarted immediately, and the following film formation is performed, and then sputtering is restarted (hereinafter, the film formation at this time is referred to as pre-film formation).

In the pre-film formation, the target 41 is sputtered without the substrate 9 being carried into the sputtering chamber 4. The reason for performing the film formation in advance is to remove foreign substances on the surface to be sputtered of the new target 41 first. Dust or the like adheres to the sputtered surface of the new target 41, or a thin oxide layer is formed on the surface. If a film is formed on the surface of the substrate 9 by sputtering the target 41 in this state, foreign substances such as dust and oxides may be mixed into the thin film, or a circuit formed on the surface of the substrate 9 may be damaged. Problem. Therefore, before restarting sputtering, the surface to be sputtered of the target 41 is sufficiently sputtered to remove foreign matter.

The second reason for performing the pre-film formation is to suppress the emission of foreign matter from the replaced deposition shields 481, 482, 483. Shield 481,482,4
The surface 83 is sufficiently cleaned and brought into the sputter chamber 4 to be attached. However, there is still a case where a slight foreign matter such as dust adheres to the surface of the deposition shields 481, 482, 483. . When sputtering is restarted in this state, the deposition shields 481, 482, 4
There is also a problem that the substrate 9 and the film forming process are stained by the foreign matter released from the substrate 83. Therefore, the shield 48
A thin film is deposited on the surfaces of 1,482 and 483 so as to trap foreign matter.

In the above-mentioned pre-film formation, the substrate holding surface of the substrate holder 44 needs to be shielded from the target 41. If not shielded, foreign substances emitted from the target 41 and sputtered particles of the material of the target 41 adhere to the substrate holding surface. In this state, if the substrate 9 is carried in and held by the substrate holder 44 in order to perform sputtering, there is a problem that foreign matter or sputter particles adhere to the back surface of the substrate 9 or the back surface of the substrate 9 is slightly shaved. . When, for example, the substrate 9 is removed from the substrate holder 44 after sputtering, foreign substances, sputter particles, the material of the substrate 9 that has been shaved, and the like are released into the sputter chamber 4 and may become particles. Therefore, it is necessary to shield the substrate holding surface of the substrate holder 44 from the target 41 during the preliminary film formation.

As a conventional example for shielding a substrate holding surface,
There is a configuration in which a member having the same size and shape as the substrate 9 (hereinafter, referred to as a dummy substrate) is arranged on the substrate holding surface of the substrate holder 44. The dummy substrate is conveyed from the atmosphere side to the sputtering chamber 4 and placed on the substrate holding surface as in the case of the normal substrate 9, and shields the substrate holding surface from the target 41. As another conventional example for shielding the substrate holding surface, a shutter mechanism may be provided. FIG. 7 shows the device of this example. As shown in FIG. 7, the sputtering chamber 4 includes a shutter chamber 47 for retracting the shutter 472.
One. The shutter 472 has a plate shape and is fixed to the upper end of the rotating shaft 473. When the rotation shaft 473 rotates, the shutter 472 moves between a position above the substrate holder 44 and a position inside the shutter chamber 471.

[0013]

Among the conventional examples of shielding the substrate holding surface, the configuration using a dummy substrate has a problem in terms of improvement in productivity. Sputter chamber 4
Is connected to the atmosphere through a load lock chamber so as not to be directly opened to the atmosphere.
In addition, load lock chamber and sputter chamber 4
And a transfer chamber provided with a transfer robot. The dummy substrate is transferred to the sputtering chamber 4 via the atmosphere side, the load lock chamber, and the transfer chamber, respectively, and returns to the atmosphere side by following the reverse path after the preliminary film formation. Therefore, it takes a considerably long time to transport the dummy substrate.

The load lock chamber is evacuated to a high vacuum every time a dummy substrate is carried in, and the load lock chamber is vented (atmospheric pressure released) every time a dummy substrate is carried out.
Is done. Such evacuation and venting also takes some time. Such transport, high vacuum evacuation and venting
The same operation is performed for the film formation process on the substrate 9, but the operation for the dummy substrate is not an original operation for the film formation process. It takes much time for such an unusual operation, which is not preferable in terms of productivity.

On the other hand, the conventional example using the shutter 472 also has the following problem. As can be seen from FIG. 7, the shutter 472 is structurally
Cannot be shielded by contacting the substrate holding surface of the substrate. The shutter 472 has to be shielded at a position slightly away from the substrate holding surface. In this case, target 4
It is necessary to prevent foreign matter and sputter particles from entering the shutter 472 and adhering to the substrate holding surface.
For this reason, the shutter 472 is slightly larger than the substrate holding surface. In this case, as understood from FIG. 7, the shutter 472 is in a state of shielding the holder shield 482 somewhat. For this reason, the holder shield 4
As a result, the sputtered particles do not sufficiently reach 82 and the film formation on the holder shield 482 becomes insufficient. As a result, when foreign matter is present on the surface of the holder shield 482, there is a problem that the foreign matter is released and becomes particles.

Further, as shown in FIG.
1 has an opening 484 for moving the shutter 472. Therefore, the main shield 481 is connected to the target 4
It is not axially symmetric about one central axis. Main shield 481
Has an effect on the electric field set in the sputtering chamber 4 by the sputtering power supply 43. If the main shield 481 is not axially symmetric, there is a problem that the axial symmetry of the electric field is easily broken and the uniformity of the formed thin film is reduced. In particular, this problem is remarkable when the sputtering power supply 43 sets a high-frequency electric field.

The invention of the present application has been made in order to solve such a problem. In a sputtering apparatus for performing pre-film formation, there is no problem in productivity, generation of particles can be effectively suppressed, and film formation can be prevented. Has the technical meaning that the homogeneity of the product is not impaired.

[0018]

In order to solve the above problems, the invention according to claim 1 of the present application is provided with a sputter chamber having an exhaust system and a sputtered surface exposed in the sputter chamber. A target, a sputter power supply for generating a sputter discharge by setting an electric field in a space facing a surface to be sputtered of the target, and a substrate held at a predetermined position in a sputter chamber to which sputter particles emitted from the target by the sputter discharge reach. In a sputtering apparatus comprising a substrate holder and forming a thin film of a target material by causing sputtered particles emitted from the target to reach the surface of the substrate, the sputtering chamber or another vacuum chamber adjacent thereto is provided in the sputtering chamber. A die with a size and shape that can cover the substrate holding surface of the substrate holder An evacuation chamber for evacuation of the substrate is provided, and a dummy moving mechanism for moving the dummy substrate between an evacuation position in the evacuation chamber and a position on the substrate holding surface of the substrate holder is provided. Having a configuration. According to a second aspect of the present invention, in order to solve the above problem, the evacuation chamber is provided with a mooring tool capable of mooring a plurality of dummy substrates at the same time. . In order to solve the above-mentioned problem, the invention according to claim 3 is based on claim 1 or 2.
In the above structure, the evacuation chamber is provided with a heater for heating the dummy substrate. Also,
In order to solve the above problem, the invention according to claim 4 is characterized in that, in the structure of claim 1, 2, or 3, irregularities are formed on the surface of the dummy substrate to prevent the deposited thin film from peeling off. Having a configuration. According to a fifth aspect of the present invention, in order to solve the above-mentioned problem, in the first aspect of the present invention, the dummy substrate is made of titanium or molybdenum.

[0019]

Embodiments of the present invention will be described below. FIG. 1 is a schematic plan view illustrating the configuration of a sputtering apparatus according to an embodiment of the present invention.
This sputtering apparatus is a multi-chamber type apparatus, and includes a transfer chamber 1 disposed in the center, a plurality of processing chambers 2, 3, 4, 100 and two load lock chambers 5 provided around the transfer chamber 1. And a chamber arrangement consisting of Each of the chambers 1, 2, 3, 4, 5, and 100 is provided with a dedicated or combined exhaust system (not shown), and is evacuated to a predetermined pressure. Each chamber 1, 2, 3, 4, 5,
A gate valve 10 is provided at a connection point between the 100's.

An autoloader 6 is provided outside the load lock chamber 5. The autoloader 6 takes out the substrates 9 one by one from the external cassette 61 on the atmosphere side and stores the substrates 9 in the cassette 51 in the lock inside 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. Load lock chamber 5
To return to. 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. In addition, there are a pretreatment etching chamber 2 for performing pretreatment etching for removing a natural oxide film or a protective film on the surface of the substrate 9 before sputtering, and a preheating chamber 3 for preheating the substrate 9 before sputtering. .

First, the configuration of the sputtering chamber 4 constituting a main part of the sputtering apparatus will be described with reference to FIG. FIG. 2 is a schematic sectional view of the sputtering chamber 4 shown in FIG. Also in the present embodiment, the sputtering chamber 4 includes an exhaust system 46. A gas introduction system 45 for introducing a gas into the sputtering chamber 4;
A target 41 provided in the sputtering chamber 4 so that the surface to be sputtered is exposed; a sputter power supply 43 for setting an electric field in a space facing the surface to be sputtered of the target 41 to generate sputter discharge; The magnet mechanism 42 provided and a substrate holder 44 for holding the substrate 9 at a predetermined position in the sputter chamber 4 where sputter particles emitted from the target 41 by the sputter discharge reach.

The sputter chamber 4 contains the gate valve 1
This is a vacuum chamber which is air-tightly connected to the transfer chamber 1 via the “0”, and is electrically grounded. And
The inside of the sputtering chamber 4 is always 10
It is configured to be evacuated to about ⁻⁴ to 10 ⁻⁶ Pa. The sputter chamber 4 has an open / close door (not shown) that is opened / closed during regular maintenance. The opening and closing door is airtightly closed via a sealing member such as an O-ring. Also, the sputtering chamber 4
A vent valve (not shown) that is opened when the inside is opened to the atmosphere is provided.

The gas introduction system 45 introduces a gas having a high sputtering rate such as argon into the inside at a predetermined flow rate. Specifically, the gas introduction system 45 includes a gas cylinder 451 storing a gas for sputter discharge such as argon, a pipe 452 connecting the sputter chamber 4 and the gas cylinder 451, a valve 453 provided in the pipe 452, and a flow rate adjustment. And the main unit 454.

The target 41 is formed of a thin film material to be formed on the surface of the substrate 9. Target 4
Reference numeral 1 is attached to the sputtering chamber 4 via an insulator 411 so as to hermetically close an opening above the sputtering chamber 4. The sputtering power supply 43 is configured to apply, for example, a negative DC voltage of 700 V to the target 41 with a power of about 30 kW. When the sputtering power supply 43 is operated in a state where a predetermined gas is introduced by the gas introduction system 45, a sputter discharge occurs and the target 41 is sputtered. A high-frequency power supply may be used as the sputtering power supply 43 in some cases.

The magnet mechanism 42 includes a center magnet 421, a peripheral magnet 422 surrounding the center magnet 421, and a disk-shaped yoke 42 connecting the center magnet 421 and the peripheral magnet 422.
And 3. The magnet mechanism 42 is provided to convert the sputter discharge into a magnetron discharge to perform efficient magnetron sputtering. That is,
A magnetic field is formed in the vicinity of the target 41 by the magnet mechanism 42, and the electrons perform a magnetron motion by the action of the magnetic field to form a plasma having a higher density. As a result, the efficiency of sputter discharge is improved, and the efficiency of film formation on the substrate 9 is also improved. The magnets 412, 42 of the magnet mechanism 42
2 are permanent magnets, but these can also be constituted by electromagnets.

The substrate holder 44 is hermetically attached to the sputtering chamber 4 via an insulating material 441.
The substrate holder 44 has a trapezoidal shape, and the substrate 9 is placed on the upper surface. The substrate holder 44 is configured so that the substrate 9 is parallel to the target 41. In some cases, a heating mechanism (not shown) that heats the substrate 9 during film formation to make film formation efficient may be provided in the substrate holder 44. When the sputter discharge is generated while the substrate 9 is held by the substrate holder 44, the sputtered particles emitted from the target 41 reach the surface of the substrate 9, and the arrival overlaps to form a thin film. The substrate holder 44 is provided with a plurality of pins 442 for transferring the substrate 9. Each pin 442 is a member fixed to the bottom surface of the sputtering chamber 4 and extending upward. The substrate holder 44 has a through hole through which each pin 442 is inserted.

Further, there is provided a holder vertical moving mechanism 441 for moving the substrate holder 44 up and down. When the substrate 9 is placed on the substrate holder 44, the substrate holder 44 is lowered to the lower limit position by the vertical movement mechanism 441 for the holder. Thereby, the upper end of each pin 442 is
The substrate holder 44 protrudes from the substrate holding surface. Then, the transfer robot 11 holding the substrate 9 places the substrate 9 on each pin 442. After the transfer robot 11 retreats the arm, the vertical movement mechanism 441 for the holder operates to move the substrate holder 44 to the upper limit position.
As a result, the substrate 9 is placed on the substrate holding surface of the substrate holder 44. When the substrate 9 is removed from the substrate holder 44, the operation is reversed.

In the apparatus of the present embodiment, similarly, three deposition shields (a main shield 481, a holder shield 482, and a ring shield 483) are provided. However, since the shutter mechanism is not used, the main shield 481 has no opening.

The major feature of the apparatus of this embodiment is that the sputter chamber 4 has an evacuation chamber 40 for the dummy substrate 91, and the dummy substrate 91 is held in the evacuation position in the evacuation chamber 40 and the substrate holder 44 in the substrate holder 44. This is the point that a dummy moving mechanism 71 for moving between the positions on the surface is provided. Hereinafter, this point will be specifically described. As shown in FIG. 1, the evacuation chamber 40 is formed on the side opposite to the side where the transfer chamber 1 is connected via the gate valve 10. The exhaust system 46 is configured to exhaust air from an exhaust port provided on the bottom wall of the sputtering chamber 4 constituting the evacuation chamber 40.

The dummy substrate 91 has the same dimensions and shape as the normal substrate 9. In selecting the material of the dummy substrate 91, consideration should be given to the prevention of peeling of the deposited thin film. Generally, when the underlayer and the thin film are made of the same material, the adhesive force of the thin film becomes high. Therefore, it is preferable that the material of the dummy substrate 91 be the same as or similar to the material of the thin film deposited on the dummy substrate 91 (that is, the material of the thin film formed on the substrate 9). . For example,
When the film formed on the substrate 9 is titanium or titanium nitride, the dummy substrate 9 is made of titanium. Further, in order to prevent peeling of the deposited thin film, high rigidity that does not cause deformation even when a large amount of thin film is deposited to a thickness of about several tens of μm is important. Therefore, the dummy substrate 91 is preferably made of metal. Considering that the dummy substrate 91 is heated to some extent during the preliminary film formation, it is also important that the material has a small thermal expansion coefficient.
In consideration of this, the material of the dummy substrate 91 may be molybdenum or the like in addition to the above-described titanium.

The dummy substrate 91 has fine irregularities on its surface to prevent the deposited thin film from peeling off. The unevenness is formed by a blast method of spraying a granular material such as sand or a spraying (or spraying) method of melting (or melting) a metal such as aluminum and spraying.

In the present embodiment, a robot similar to the transfer robot 11 is used as the dummy moving mechanism 71. The dummy movement mechanism 71 performs each of the expansion and contraction (horizontal movement) of the arm 711 holding the dummy substrate 91, the vertical movement of the arm 711, and the rotation of the arm 711 (rotation about a vertical rotation axis). Has become.

FIG. 3 is a schematic sectional view for explaining the operation of the dummy moving mechanism 71. When the dummy substrate 91 is arranged on the substrate holding surface of the substrate holder 44, the substrate holder 44 is lowered to the lower limit position by the holder up / down movement mechanism 441. The dummy moving mechanism 71 moves the arm 711 holding the dummy substrate 91 to a height slightly higher than the upper end of each pin 442. Next, the dummy moving mechanism 71 rotates the arm 711 to move the dummy substrate 9.
1 is positioned directly above the substrate holding surface of the substrate holder 44. In this state, the dummy moving mechanism 71 moves the arm 711.
Is lowered within a range that does not collide with the substrate holder 44. During this lowering, as shown in FIG. 3, the dummy substrate 91 rests on each pin 442. Thereafter, the dummy moving mechanism 71
Rotates the arm 711 backward and then returns to the original posture.

Then, the vertical movement mechanism 441 for the holder is driven, and the substrate holder 44 is raised to the upper limit position. During this ascent, the dummy substrate 91 is placed on the substrate holding surface of the substrate holder 44. Note that the upper limit position where the substrate holder 44 is located is the same position as the position where normal sputtering is performed.

Next, the pre-processing etching chamber 2 of the plurality of processing chambers shown in FIG. 1 will be described. The pre-treatment etching chamber 2 is configured to remove a natural oxide film or a protective film by sputter-etching the surface of the substrate 9 by high-frequency discharge. If a film is formed in the sputtering chamber 4 while such an insulating film is formed, there is a problem that adhesion to a base is deteriorated, and in the case of a conductive film, conductivity to the base is reduced. Therefore, prior to the film formation in the sputtering chamber 4, the substrate 9
The surface is etched.

The pre-treatment etching chamber 2 is provided with a gas introduction system for introducing a gas such as argon or nitrogen therein, a high-frequency electrode, a high-frequency power supply for applying a high-frequency voltage to the high-frequency electrode to generate a high-frequency discharge. I have. The high-frequency electrode has a substrate 9 in the pretreatment etching chamber 2.
, And a high frequency voltage is often applied to the substrate holder via a capacitor for generating a self-bias voltage on the substrate 9.

The preheating (preheating) in the preheating chamber 3 is performed for the purpose of releasing the occluded gas from 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.

As shown in FIG. 1, a further vacuum chamber 1 is provided around the separation chamber 1.
00 is provided. These vacuum chambers 100
If necessary, the same configuration as the sputter chamber 4 may be used to improve the productivity, or when laminating different types of thin films, the sputter chamber 4 may be provided with a target 41 of a different material. Or, after the film formation process,
In some cases, the cooling chamber may be a cooling chamber for cooling the substrate 9.

The apparatus of the present embodiment has a control unit (not shown) for controlling the operation of the entire apparatus. The control unit is a microcomputer, and includes a storage unit (not shown) that stores a program for controlling each unit and the like, and a display unit (not shown) that performs various displays such as an operation state of the apparatus.

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 by the autoloader 6 into the in-lock cassette 51 in the load lock chamber 5. The substrate 9 carried into the lock cassette 51 is transferred by the transfer robot 11 provided in the separation chamber 1.
First, the wafer is carried into the pretreatment etching chamber 2 and pretreatment etching is performed. Next, the substrate 9 is conveyed 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 carried out of the sputtering chamber 4 by the transfer robot 11 and stored in the cassette 51 inside the lock. The processed substrate 9 stored in the cassette 51 inside the lock is stored in the external cassette 61 by the autoloader 6. By repeating such an operation, a single wafer processing is sequentially performed on a large number of substrates 9.

When the predetermined number of times of the single-wafer processing has been reached, the control unit displays on the display unit that the time of the regular maintenance has been reached. When this display is displayed, the operator opens the vent valve (not shown), returns the inside of the sputtering chamber 4 to the atmospheric pressure, and then opens the open / close door (not shown). Then, the target 41 and the shields 481, 482,
Work such as replacement of 483 is performed.

Thereafter, the opening / closing door is closed, the vent valve is also closed, and the inside of the sputtering chamber 4 is again evacuated to a high vacuum by the exhaust system 46. In this state, as described above, the dummy moving mechanism 71 is operated to place the dummy substrate 91 on the substrate holding surface of the substrate holder 44. Then, the sputter power supply 43 is operated, and the replaced target 41 is sputtered to form a film in advance. At this time, a film is deposited on the surface of the dummy substrate 91 in addition to the replaced deposition shields 481, 482, 483.

After the preliminary film formation, the dummy moving mechanism 7
1 returns the dummy substrate 91 to the retreat position in the retreat chamber 40. Then, after the inside of the sputtering chamber 4 is evacuated again to a high vacuum, the next substrate 9 is carried in, and the film forming process by sputtering is restarted.

Further, the control unit has a storage unit (not shown) for storing the number of times of preliminary film formation using one dummy substrate 91. When the number of times of preliminary film formation using one dummy substrate 91 reaches a predetermined number, the control unit
1 is displayed on the display unit. When this display is displayed, the operator also replaces the dummy substrate 91 with a new one at the time of periodic maintenance. For this reason, generation of particles due to deposition and peeling of a thin film more than the limit on the dummy substrate 91 is prevented.

As can be understood from the above description, according to the apparatus of this embodiment, the dummy substrate 91 is
Is moved only between the retracted position set in the inside and the position on the substrate holding surface of the substrate holder 44, the time for the movement comes from the atmosphere side via the load lock chamber 5 and the transfer chamber 1. It is much shorter than the case. Further, since the dummy substrate 91 is always located in the vacuum atmosphere in the sputtering chamber 4, the dummy substrate 91
There is no need to repeat high vacuum evacuation and venting for loading and unloading. Therefore, the total time required for the pre-film formation while using the dummy substrate 91 is significantly shorter, which is extremely favorable in terms of productivity. The configuration in which the dummy substrate 91 is always arranged on the vacuum side is as follows.
There is also an advantage that there is no problem that foreign substances such as dust and impurity gases such as water are brought into the sputtering chamber 4 from the atmosphere side via the dummy substrate 91. Further, since it is not a shutter mechanism, it is not necessary to provide an opening in the main shield 481. Therefore, the thin film formed on the surface of the substrate 9 does not become non-uniform due to the non-uniformity of the sputter discharge.

Next, a second embodiment of the present invention will be described. FIG. 4 is a diagram showing a main part of the sputtering apparatus according to the second embodiment, and is a schematic sectional view similar to FIG. A feature of the apparatus of the embodiment shown in FIG. 4 is that the dummy substrate 91 is provided in the evacuation chamber 40 for retracting the dummy substrate 91.
Is provided with a mooring tool 72 for mooring a plurality.
The mooring tool 72 is attached to the upper wall of the sputter chamber 4 constituting the evacuation chamber 40.

The mooring tool 72 has a structure including a pair of side plates and a plurality of convex portions provided on the inner surfaces of the pair of side plates. The pair of side plates are parallel to each other along a direction connecting the substrate holder 44 and the evacuation chamber 40. The convex portions are long in this direction, and are provided three at predetermined intervals above and below. The arrangement positions of the projections on the pair of side plates are at the same height. The dummy substrate 91 is moored with its peripheral edge placed on the protrusions on both sides at the same height. Therefore, in this embodiment, the three dummy substrates 91
Are moored at the same time.

The device shown in FIG. 4 operates basically in the same manner as the device shown in FIGS. However, the control in the control unit is slightly different, and will be described below. The control unit stores the number of times of use of the three dummy substrates 91 moored to the mooring tool 72 in the storage unit. In the following description,
The three dummy substrates 91 are a dummy substrate 91A, a dummy substrate 91B, and a dummy substrate 91C.

FIG. 5 is a diagram for explaining a control program provided in the control unit in the apparatus shown in FIG.
As described above, after repeating a predetermined number of times of the sputtering single-wafer processing, the operator performs regular maintenance. Then, the operator inputs a “preliminary film formation command” from the input unit to perform the preliminary film formation. When receiving the “preliminary film formation command” input from the input unit, the control unit reads out from the storage unit which dummy substrate 91 was used in the previous preliminary film formation. In addition, data of the number of times of use, which is the number of times the preliminary film formation has been performed by using the dummy substrate 91 up to the previous time, is similarly read out from the storage unit.

Then, the data of “the number of times of use” is compared with the data of “the number of times of limit” which is set in advance as a limit of the number of times that one dummy substrate 91 can be used. For example,
Assuming that the dummy substrate 91A was used last time,
If the “number of uses” is equal to or less than the “limit number”, a command of “preliminary film formation execution” is issued. As a result, as described above, the dummy moving mechanism 71 operates to operate the dummy substrate 91.
Is disposed on the substrate holding surface of the A substrate holder 44, and the target 41 is preliminarily formed by sputtering. At this time, the control signal sent from the control unit 25 to the dummy moving mechanism 71 is a signal for controlling to use the same dummy substrate 91A as the previous pre-film formation. Thereafter, 1 is added to the "number of uses", and the program returns to "start".

If the "number of times of use" has reached the "limit number of times", the "change to dummy substrate 91B" process for changing the control signal sent to the dummy moving mechanism 71 to change to the dummy substrate 91B is performed. I do. After that, similarly, a command of “preliminary film formation execution” is issued, and the process returns to the start.

The same applies to the case where the dummy substrate 91 used last time is the dummy substrate 91B.
If the “limit number” has been reached, processing of “change to dummy substrate 91C” is performed. Then, the dummy substrate 91 used last time
Is the dummy substrate 91C, the "use count"
If the number has reached the “limit number” −1, the process of “dummy substrate replacement display” for displaying on the display unit that the dummy substrate 91 needs to be replaced at the next periodic maintenance is performed. This information is also stored in the storage unit, and is automatically displayed on the display unit at the time of the next periodic maintenance.

As can be understood from the above description, in the present embodiment, the preliminary film formation is performed while sequentially using the three dummy substrates 91, so that the replacement of the dummy substrate 91 is more difficult than in the case where one dummy substrate 91 is used. The number of pre-film formations that can be performed in a large number increases. Therefore, the amount of work at the time of regular maintenance is reduced, and the productivity is improved.

Next, a third embodiment of the present invention will be described. FIG. 6 is a diagram showing a main part of a sputtering apparatus according to the third embodiment, and is a schematic cross-sectional view similar to FIG. A feature of the sputtering apparatus according to the third embodiment shown in FIG. 6 is that a heater 73 for heating the dummy substrate 91 in the evacuation chamber 40 is provided. Heater 7
Reference numeral 3 is provided for the purpose of suppressing peeling of a thin film deposited on the dummy substrate 91. When the heater 73 is not provided, the temperature of the dummy substrate 91 is at room temperature before the preliminary film formation is performed. When the film is formed in advance, the film is exposed to plasma formed by sputter discharge, so that the film is several hundred degrees (for example, about 200 ° C.)
The temperature rises rapidly to the extent. Then, after the completion of the preliminary film formation, the temperature is again lowered to room temperature. When the rapid temperature increase and decrease are repeated in this manner, the thin film deposited on the dummy substrate 91 undergoes thermal distortion, and the thin film is liable to peel off. Peeling of the thin film causes particles.

Therefore, in the present embodiment, while the dummy substrate 91 is being retracted into the evacuation chamber 40, the temperature of the dummy substrate 91 is increased to some extent. Due to this heating, a rapid change in temperature is suppressed, and generation of particles due to peeling of the thin film is prevented. Dummy substrate 9 in evacuation room 40
The heating temperature of 1 may be, for example, about 100 ° C to 200 ° C. There should be no temperature difference of about 50 ° C. or more from the temperature at the time of the preliminary film formation.

The heater 73 is attached to the upper wall of the sputtering chamber 4 constituting the evacuation chamber 40. As the heater 73, a lamp heater using an infrared lamp or the like, a sheath heater that generates Joule heat, or the like can be used. The inside of the sputtering chamber 4 is a vacuum atmosphere, and considering that heat transfer due to convection or conduction is not so expected, a lamp heater (radiant heating) is suitable. However, when a pedestal-shaped member provided with a heater is provided inside and the dummy substrate 91 is placed on the pedestal and heated, conduction and transmission may be used. In this case, a Joule heater is also effective. In the first or second embodiment described above, it is of course possible to provide the heater 73 as in this embodiment.

In the above embodiments, the evacuation chamber 40 is provided in the sputter chamber 4, but a space in another vacuum chamber connected adjacent to the sputter chamber 4 may be used as the evacuation chamber 40. In this case, a gate valve is provided between the sputtering chamber 4 and another vacuum chamber.

In each of the above embodiments, the dummy substrate 9
1 has the same dimensions and shape as the substrate 9, in order to cover the region of the substrate holding surface covered by the substrate 9 during sputtering (hereinafter, holding region) in the same manner. If the dummy substrate 91 is smaller than the substrate 9, a thin film is deposited on a part of the holding region during the preliminary film formation. Then, during sputtering, the substrate 9 is placed on this thin film,
It may cause particle generation. The problem when the dummy substrate 91 is larger than the substrate 9 is not so serious, but when the dummy substrate 91 is large enough to shield the holder shield 482, the holder shield 482 is not partially preliminarily formed. I will.
As a result, there is a fear that foreign matter is released.

As can be understood from the above description, the term “size and shape similar to the substrate” means the size and shape in a plane along the substrate holding surface, and the thickness of the plate may not be the same. . However, if the dummy substrate 91 is too thick, the movement by the dummy moving mechanism 71 may be hindered, or sputter particles from the target 41 may be shielded depending on the thickness at the time of preliminary film formation. It costs. However,
The dimensions and shape of the substrate 9 are the same as those of the dummy substrate 91.
It is not a mandatory condition for. To the extent that there is no problem,
The size and shape may be different from those of the substrate 9.

Some sputtering apparatuses perform self-sustained sputtering for maintaining discharge only by ionization of sputter particles emitted from the target 41.
The invention of the present application is also applicable to this type of device.

[0063]

Next, an example of pre-film formation will be described. The preliminary film formation can be performed under the following conditions.
The “sputter power” is the product of the voltage applied to the target 41 and the current flowing through the target 41. -Gas: Argon-Gas flow rate: 50 cc / min-Pressure: 0.23 Pa-Sputter power: 2 kW-Deposition time: 20 minutes When the deposition process is repeated under the above conditions, the dummy substrate 91 needs to be replaced about 400 times. become.

[0064]

As described above, according to the first aspect of the present invention, the dummy moving mechanism for moving the dummy substrate between the evacuation chamber and the position on the substrate holding surface of the substrate holder is provided. Therefore, the time required for moving the dummy substrate and the like is short, and the entire time required for the preliminary film formation is also short. For this reason, productivity is improved. Since the dummy substrate is always arranged on the vacuum side, there is no problem that foreign matter such as dust and impurity gas such as water are brought into the sputtering chamber from the atmosphere side via the dummy substrate. According to the second aspect of the present invention,
In addition to the above effects, since a plurality of dummy substrates are moored in the evacuation room and used sequentially, the cycle of replacement of the dummy substrates becomes longer. For this reason, productivity is further improved. Also,
According to the third aspect of the present invention, in addition to the above effects, the dummy substrate is heated in the evacuation chamber, so that a rapid decrease in temperature of the dummy substrate is suppressed. Therefore, generation of particles due to peeling of the thin film deposited on the dummy substrate is suppressed. According to the fourth aspect of the present invention, in addition to the above-described effects, since irregularities are formed on the surface of the dummy substrate, generation of particles due to peeling of the deposited thin film is further suppressed. According to the fifth aspect of the present invention, in addition to the above-described effects, since the dummy substrate is made of metal, generation of particles due to peeling of the deposited thin film is further suppressed.

[Brief description of the drawings]

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

FIG. 2 is a schematic sectional view of the sputtering chamber 4 shown in FIG.

FIG. 3 is a schematic sectional view illustrating the operation of the dummy moving mechanism 71.

FIG. 4 is a diagram illustrating a main part of a sputtering apparatus according to a second embodiment, and is a schematic cross-sectional view similar to FIG. 2;

FIG. 5 is a diagram illustrating a control program provided in a control unit in the device shown in FIG.

FIG. 6 is a diagram showing a main part of a sputtering apparatus according to a third embodiment, and is a schematic sectional view similar to FIG. 2;

FIG. 7 is a cross-sectional view illustrating a schematic configuration of a conventional sputtering apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transfer chamber 11 Transfer robot 4 Sputter chamber 40 Evacuation room 41 Target 42 Magnet mechanism 43 Sputter power supply 44 Substrate holder 45 Gas introduction system 46 Exhaust system 481 Prevention shield 482 Prevention shield 483 Prevention shield 71 Dummy moving mechanism 72 Mooring tool 73 heater 9 substrate 91 dummy substrate

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Makoto Sato 5-81-1, Yotsuya, Fuchu-shi, Tokyo Anelva Co., Ltd. (72) Inventor Seiji Itani 5-81-1, Yotsuya, Fuchu-shi, Tokyo Anelva, Inc. F term (reference) 4K029 AA00 BD01 CA05 DA01 DA09 FA09 JA01 KA01 4M104 DD39 HH20 5F103 AA08 BB25 BB34 BB36 BB45 BB60 HH03 LL14 RR01

Claims (5)

[Claims] 1. A sputter chamber having an exhaust system,
A target provided such that the surface to be sputtered is exposed in the sputtering chamber, a sputter power supply for setting an electric field in a space facing the surface to be sputtered of the target to generate a sputter discharge, and a target discharged from the target by the sputter discharge. A sputtering apparatus, comprising: a substrate holder that holds a substrate at a predetermined position in a sputtering chamber to which sputtered particles reach; and a sputtered particle emitted from the target reaches a surface of the substrate to form a thin film of a target material. In the sputtering chamber or another vacuum chamber adjacent to the sputtering chamber, there is provided an evacuation chamber for evacuation of a dummy substrate having a size and shape capable of covering the substrate holding surface of the substrate holder. Position and a position on the substrate holding surface of the substrate holder. A sputtering apparatus comprising a dummy moving mechanism for moving a mee substrate. 2. The sputtering apparatus according to claim 1, wherein the evacuation chamber is provided with a mooring tool capable of mooring a plurality of dummy substrates simultaneously. 3. The sputtering apparatus according to claim 1, wherein the evacuation chamber is provided with a heater for heating the dummy substrate. 4. The sputtering apparatus according to claim 1, wherein irregularities are formed on the surface of the dummy substrate to prevent the deposited thin film from peeling off. 5. The sputtering apparatus according to claim 1, wherein the dummy substrate is made of titanium or molybdenum.