JP2015214715A - Sputtering apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sputtering apparatus which allows easily changing a control method to improve a film thickness distribution.SOLUTION: A sputtering apparatus 100 according to the invention includes: three or more of cathode partition walls 9 arranged in a substrate transportation direction to hold a target 4 for sequentially depositing a film to a substrate transported on a transportation roller 3; and a control selection unit 25 which selects and executes a control method which provides a most uniform film thickness distribution among multiple control methods for controlling a magnet driving unit 11 according to a transportation speed and the number of the target 4 used for deposition treatment.

Description

  The present invention relates to a sputtering apparatus. In particular, the present invention relates to a sputtering apparatus that is implemented by a substrate transfer type continuous sputtering film forming apparatus including a plurality of sputtering units and that sequentially forms films on a substrate by a sputtering action while reciprocating a magnet in each sputtering unit.

  As an apparatus for efficiently forming a film on a large number of substrates, an in-line continuous sputtering film forming apparatus of a substrate transport type in which a plurality of sputter units are arranged side by side is known. The substrate is continuously transferred to the vacuum chamber and passes through the sputtering chamber in which the sputtering unit is installed at a constant speed. A film forming material released from a target provided in the sputtering unit while passing through the sputtering chamber is deposited on the substrate to form a film. The film thickness at this time is determined by the power supplied to the cathode and the transport speed of the substrate. When the required film thickness cannot be obtained by film formation using one sputter unit, the film formation is performed in a plurality of times using a plurality of sputter units.

  On the other hand, the sputtering action occurs in the vicinity of the magnetic field generated on the target surface side. In the magnetron sputtering apparatus, since a magnet (magnetic circuit) is disposed on the back side of the target, sputtered atoms are emitted from a region corresponding to the position of the magnet. The magnet is reciprocated to improve the target utilization rate and reduce the reattachment area of the sputtered film to the target surface. If the magnet is reciprocated in the substrate transport direction at a speed close to the substrate transport speed Vt, the film thickness on the substrate will be alternately thick and thin in the transport direction, resulting in poor film thickness distribution in the transport direction. Become.

  One method for improving the film thickness distribution is to operate the magnet at a high speed with respect to the substrate transport speed Vt. In this method, the magnets are operated sufficiently fast with respect to the substrate transfer speed to make the film formation distribution uniform in each sputtering unit. In this specification, a control method for making the film thickness distribution uniform by this method is referred to as “simple oscillation control”.

  As another method for improving the film thickness distribution, a method of making the film thickness in the transport direction uniform using two sputtering units is known (see, for example, Patent Document 1). In this method, the magnet swing of each sputtering unit is controlled in accordance with the substrate transport speed. That is, a film formed on the substrate by one sputtering unit is formed on the thick region formed on the substrate by one sputtering unit, and a thin film is formed by the other sputtering unit. This is a method of averaging and improving the film thickness distribution in the transport direction by depositing a thick film on the thin region with the other sputtering unit. This method is particularly effective when the substrate transport speed is high. This method can lower the swing speed of the magnet as compared with “simple swing control”. In the present specification, a control method for making the film thickness distribution uniform by this method is referred to as “two-magnet swing control”.

  Conventional substrate transfer type in-line continuous sputtering film forming apparatuses often use the same film forming process for many years for mass production of the same product. Therefore, sputtering apparatuses that employ only one of the above-described “simple swing control” and “two-magnet swing control” have been supplied to the market.

JP 2002-146528 A International Publication No. 2009/093598

  However, with the diversification of products to be mass-produced, the film forming process is being changed in a short period of time in recent substrate transport type in-line continuous sputter film forming apparatuses. If the conveyance speed is changed with the change of the film forming process, it is expected that the control method for improving the film thickness distribution needs to be changed.

  This invention is made | formed in view of the said subject, Comprising: It aims at providing the sputtering device which can change the control method which improves film thickness distribution simply.

  The sputtering apparatus of the present invention holds a vacuum container, a substrate transport unit for transporting a substrate in the vacuum container, and a target for sequentially forming a film on the substrate transported by the substrate transport unit. Therefore, at least three target holding units arranged in the substrate transport direction, a magnet unit disposed on the back side of each target holding unit, a magnet driving unit that drives the magnet unit, and the target holding unit When the film is formed while holding the target, a more uniform film thickness distribution can be obtained from a plurality of methods for controlling the magnet driving unit according to the substrate transport speed and the number of the targets used. And a selection unit that selects a method to be obtained.

  According to the present invention, it is possible to provide a sputtering apparatus that can easily change the control method for improving the film thickness distribution. In particular, when performing multiple types of film formation with the same sputtering apparatus, it can be easily changed to a control method that can obtain the most uniform film thickness at the transport speed of the film formation process and the number of targets used, A sputtering apparatus suitable for manufacturing a wide variety of products can be provided.

It is a schematic sectional drawing of the film-forming chamber of the sputtering device which concerns on the 1st Embodiment of this invention. It is a schematic diagram of the movement of the magnet in the substrate transport direction in simple swing control. FIG. 3 is a velocity diagram showing a velocity change for one cycle of movement of the magnet of FIG. 2. FIG. 6 is a relationship diagram between a film forming condition and a film thickness distribution in simple swing control. It is a schematic diagram of the movement of the magnet in the substrate transport direction in the two-magnet swing control. FIG. 6 is a velocity diagram showing a velocity change for one cycle of movement of the magnet of FIG. 5. It is a velocity diagram showing movement of two magnets in 2 magnet swing control. It is a schematic diagram showing the relative speed and film thickness of the magnet with respect to the substrate to be transported for any one sputter unit of 2-magnet swing control. It is a schematic diagram of the relationship between relative speed _Vms with respect to a board | substrate and a film thickness about each magnet of 2 magnet rocking | fluctuation control. It is a schematic diagram of the film thickness on the board | substrate formed into a film by 2 magnet rocking | fluctuation control. It is a schematic diagram showing a range of a cycle T that can be selected with respect to the substrate transport speed Vt in each of simple swing control and two-magnet swing control. It is a schematic diagram showing a range of a cycle T that can be selected with respect to the substrate transport speed Vt in each of simple swing control and two-magnet swing control. It is a flowchart of the program which selects the control method of operation | movement of a magnet. It is a schematic sectional drawing of the film-forming chamber of the sputtering device which concerns on the 2nd Embodiment of this invention. It is a schematic diagram of the movement of the magnet in the substrate transport direction in the two-magnet swing control. FIG. 16 is a velocity diagram showing a velocity change for one cycle of movement of the magnet of FIG. 15. It is explanatory drawing of the positional relationship of three magnets and a board | substrate which concerns on 2nd Embodiment of this invention. It is a velocity diagram showing the movement of three magnets in the three-magnet swing control. It is a schematic diagram showing the relative speed and film thickness of the magnet with respect to the substrate to be transported, for any one sputter unit of 3 magnet swing control. It is a schematic diagram of the relationship between the relative speed V _ms with respect to the substrate and the film thickness for each magnet of the three-magnet swing control. It is a schematic diagram showing a range of a cycle T that can be selected with respect to the substrate transport speed Vt in each of simple swing control and 3-magnet swing control. It is a schematic diagram showing a range of a cycle T that can be selected with respect to the substrate transport speed Vt in each of simple swing control and 3-magnet swing control. It is a flowchart of the program which selects the control method of operation | movement of a magnet. It is a flowchart of the program which performs grouping when using an arbitrary number of sputtering units.

  Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the members, arrangements, and the like described below are examples embodying the present invention and do not limit the present invention, and it goes without saying that various modifications can be made in accordance with the spirit of the present invention. In the embodiment, an example of an apparatus having two or three magnetron sputtering units in one film forming chamber will be described as a sputtering apparatus. The present invention can be suitably applied to an apparatus including a unit.

(First embodiment)
A sputtering apparatus that automatically switches the control method of two sputtering units according to the first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view for explaining the configuration of a film forming chamber of a substrate transfer type in-line continuous sputter film forming apparatus (sputtering apparatus) 100 applicable to the present invention. Normally, a plurality of chambers such as a load lock chamber, a buffer chamber, and an unload lock chamber are connected via a gate valve to form a single substrate transfer type in-line continuous sputter deposition apparatus. Only the deposition chamber is shown.

  As shown in FIG. 1, the film forming chamber is installed on a chamber 2 (vacuum container), a substrate transport unit for transporting the substrate 1 provided in the chamber 2 (vacuum container), and an upper portion of the chamber 2. It consists of two magnetron sputtering units (sputtering units) 10. The substrate transport unit includes a transport roller 3 and a transport control device 21 that controls the transport roller 3. In this embodiment, the substrate 1 is placed on the transport roller 3 in a horizontal state and is transported at a constant speed in the right direction in the drawing. The chamber 2 is evacuated to vacuum by an exhaust pump (not shown), and a process gas (for example, Ar gas) is supplied to a predetermined pressure by a gas pipe (not shown). In the sputtering unit 10, first and second sputtering units 10a and 10b are arranged from the upstream side in the substrate transport direction. Each sputter unit 10a, 10b has the same configuration. In addition, although the sputtering apparatus 100 is drawn as a structure provided with two sputtering units, you may provide three or more sputtering units. When the sputtering apparatus 100 includes three or more sputter units, any two sputter units 10a and 10b are used.

  In the present embodiment, the targets 4a and 4b included in the two sputter units 10a and 10b are made of the same material. The cathode partition walls (target holding portions) 9a and 9b of the sputter units 10a and 10b are installed on the ceiling wall of the chamber 2 via the cathode insulating portions 8a and 8b. Cathode partition walls 9a and 9b are provided with cathodes 6a and 6b to which power is supplied by a power supply device (not shown). Here, DC power is supplied to the cathodes 6a and 6b. The targets 4a and 4b are bonded to the cathodes 6a and 6b by a method such as bonding, and the cathodes 6a and 6b and the targets 4a and 4b are fixed to the cathode partition walls 9a and 9b in an integrated state. The cathodes 6a and 6b are sometimes called target back plates or backing plates. A water channel (not shown) is provided inside the cathode for flowing a coolant for cooling the targets 4a and 4b.

  In order to prevent sputtering other than the surfaces of the targets 4a and 4b, the target shield 5a is covered so as to cover the target side surface, the cathodes 6a and 6b, and the exposed surfaces of the cathode partition walls 9a and 9b with a gap of 2 to 3 mm. , 5b are provided. Magnets 7a and 7b (magnet portions) are respectively installed on the opposite sides (atmosphere side or back side) of the cathode partition walls 9a and 9b from the cathodes 6a and 6b. The magnets 7a and 7b are composed of a flat yoke and a permanent magnet, and are composed of a central pole with the cathode side as the S pole and an outer peripheral pole with the cathode side as the N pole. Magnetic field lines created by the magnets 7a and 7b form two tunnel-like loops near the target surface. When discharged, a high density plasma is generated at the location of the magnetic field lines near the target surface.

  On the target surface, erosion (erosion of the target) occurs at a location corresponding to the high-density plasma determined by the magnet position. Sputter deposition is performed while moving the magnets 7a and 7b with respect to the targets 4a and 4b, thereby making it possible to improve target utilization by creating erosion with a uniform depth on the target surface.

  The magnets 7a and 7b can be reciprocated in the conveying direction of the substrate 1 by magnet driving devices 11a and 11b (magnet driving units). The magnet driving devices 11a and 11b are constituted by a power transmission mechanism such as a motor or a ball screw (not shown). The motors (magnet drive devices 11a and 11b) for driving the magnet 7 are controlled by the magnet control device 22, and can move the magnets 7a and 7b to a designated position at a designated speed. The speed control of the magnets 7a and 7b was a trapezoidal drive consisting of acceleration, constant speed, and deceleration.

  The magnets 7a and 7b are stopped again from the stopped state by an acceleration movement with a constant acceleration, followed by a constant speed movement, and subsequently a deceleration movement with a constant acceleration. The distance moved during this time is the area of the trapezoidal portion of the velocity diagram drawn as the vertical axis velocity and the horizontal axis time. There are two control methods (methods) for operating the magnets 7a and 7b: simple swing control and two-magnet swing control, and one of them is selected by the control selection unit 25 (selection unit). Each control method will be described later. The control selection unit 25 includes a RAM in which a program for selecting a control method to be described later and a magnet control device 22 are stored, and is connected to a storage unit 27 and a transport control device 21 that store a plurality of methods for controlling the magnet drive unit. Has been.

A sputtering film forming method using the sputtering apparatus 100 will be described.
A process gas (for example, Ar gas) is introduced into the chamber 2 that is evacuated to a predetermined pressure, and the substrate 1 is transported at a constant transport speed (constant speed transport). Cooling water is supplied in advance to the water channels of the cathodes 6a and 6b. In the control selection unit 25 of the magnet control method, either simple swing control or two-magnet swing control is selected in advance. The selection of the control method is mainly determined by the substrate conveyance speed, and the selection method will be described later. The magnet drive device is controlled by either the simple swing control or the control method of the two-magnet swing control to reciprocate the magnets 7a and 7b in the transport direction of the substrate 1. A constant DC power is applied to the cathodes 6a and 6b to perform magnetron sputtering film formation. When sputter deposition is performed in this manner, a uniform film is deposited on the substrate in the transport direction.

Here, the operation of the magnet in the simple swing control will be described.
FIG. 2 shows an example of the movement of the magnet 7 (7a or 7b) in the simple swing control. The horizontal axis of the graph represents time, the vertical axis represents the magnet position in the substrate transport direction with respect to the cathode 6 (6a or 6b), the cathode center position is 0 mm, the forward direction being the substrate transport direction is positive, and the reverse direction is negative. . The one-way distance of the reciprocating movement of the magnet 7 is called a stroke. Here, the stroke is 100 mm. Initially, the magnet is at the +50 mm position, which is the forward stroke end. Starting from here, the magnet 7 moves in the reverse direction, moves to −50 mm which is the stroke end in the reverse direction, and stops for a certain time. Next, the magnet 7 moves in the forward direction in the opposite direction, moves to the +50 mm position which is the stroke end in the forward direction, and stops for a certain time. This is one cycle, and thereafter this operation is repeated.

  FIG. 3 is a velocity diagram showing the velocity change for one cycle of the movement of the magnet 7 in FIG. The horizontal axis represents time, and the vertical axis represents the velocity Vmc of the magnet 7 with respect to the cathode 6, and the direction of the velocity is positive in the forward direction, which is the substrate transport direction, and negative in the reverse direction. The magnet 7 is accelerated at a constant acceleration for the time Tacc1 until the speed 7 reaches the speed Vb in the first reverse direction. After that, it moves in the reverse direction at a constant speed Vb (in FIG. 3, since the reverse direction is negative, it is set to −Vb), and then decelerates in the reverse direction at a constant acceleration for a time Tacc2, and the speed becomes zero. The shape of the velocity diagram so far shows a trapezoid. In this embodiment, speed control generally referred to as trapezoidal driving (also referred to as trapezoidal control) is employed. This is a general method for controlling motor drive.

  By the speed control so far, the magnet has moved from the +50 mm position at the forward stroke end of the initial position shown in FIG. 2 to the −50 mm position at the reverse stroke end. After that, the speed is maintained at 0 mm / s because Tsew stops for a certain time. Next, a trapezoidal drive of acceleration, constant speed (+ Vf), and deceleration is performed in a forward direction (indicated as a positive speed in FIG. 3), and Tsew stop is performed for a fixed time. The forward direction is the same as the reverse direction.

The film thickness distribution in the transport direction on the substrate when the sputter film formation is performed while the magnet 7 is reciprocated in the substrate transport direction by simple swing control will be described. In film formation employing the control method of simple swing control, it is known that the film thickness becomes uniform when the film is moved by moving the magnet to some extent faster. FIG. 4 shows film forming conditions and film thickness distribution in the control method of simple oscillation control. The horizontal axis of the graph in FIG. 4 indicates the distance traveled by the substrate while the magnet reciprocates once in the substrate transport direction at (transport speed Vt) × (cycle T). The vertical axis in FIG. 5 is the film thickness distribution in the substrate transfer direction, and shows the film pressure distribution with respect to Vt · T. The following calculation formula (film thickness distribution calculation formula) was used for the film thickness calculation.

Film thickness distribution (±%) = (maximum value−minimum value) / (maximum value + minimum value) × 100

The film thickness distribution in the substrate transport direction becomes almost zero under the condition that Vt · T is smaller than about 70 mm. Therefore, if the transport speed Vt and the cycle T satisfy the following conditions, the film thickness becomes uniform even in the sputtering film formation method operated by the simple oscillation control.

Vt · T <70mm (1)

Next, the operation of the magnet in the two-magnet swing control will be described below.
The two-magnet swing control is a control method in which the operation of the pair of magnets 7a and 7b and the conveyance of the substrate 1 are interlocked. FIG. 5 shows an example of the movement of the magnet 7 (7a or 7b) in the substrate transfer direction in the two-magnet swing control, and FIG. 6 shows the velocity diagram. In this example, the stroke L (one way) of the reciprocating movement of the magnet 7 is 100 mm, and the period T of the reciprocating movement is 9 seconds. In the present embodiment, trapezoidal driving considering acceleration and deceleration of the magnet 7 is adopted. Also, it stops for a predetermined time at the stroke end.

  The vertical axis in FIG. 5 is the magnet position, and the forward position, which is the substrate transport direction, is positive and the reverse direction is negative, with the center position of the cathode 6 (6a or 6b) being 0 mm. First, the magnet 7 is located at the +50 mm position (initial position) which is the stroke end in the forward direction. The magnet 7 starts from here and moves in the reverse direction, and temporarily stops at the −50 mm position which is the stroke end in the reverse direction. Next, the magnet 7 moves in the forward direction in the opposite direction, moves to the +50 mm position, which is the stroke end in the forward direction, and similarly stops. This is one cycle in 9 seconds. Thereafter, this operation is repeated. The magnet 7 is controlled so that the moving speed in the reverse direction is fast and the moving speed in the forward direction is slow.

  FIG. 6 is a velocity diagram showing the velocity change for one cycle of the movement of the magnet 7 in FIG. The horizontal axis represents time, and the vertical axis represents the velocity Vmc of the magnet 7 with respect to the cathode 6, and the direction of the velocity is positive in the forward direction, which is the substrate transport direction, and negative in the reverse direction. The magnet 7 first accelerates at a constant acceleration in the reverse direction for a certain time, then moves at a constant speed in the reverse direction, decelerates at the constant acceleration in the reverse direction, and temporarily stops. In this embodiment, speed control generally referred to as trapezoidal driving is employed.

  By the speed control up to this point, the magnet has moved from the +50 mm position at the forward stroke end of the initial position shown in FIG. 5 to the −50 mm position at the reverse stroke end. After that, the speed is kept at 0 mm / s because the motor stops for a certain time. Next, the magnet performs trapezoidal driving and stopping of acceleration, constant speed, and deceleration in the forward direction (positive speed in FIG. 6). However, the forward constant velocity and the constant velocity time are different from the movement of the magnet 7 in the reverse direction. The forward movement of the magnet 7 is smaller in absolute value of the constant speed and longer in the constant speed than the backward movement.

  Up to this point, an example of the movement of the magnet 7 (7a or 7b) of one sputter unit 10 (10a or 10b) has been shown. FIG. 7 shows an example of the movement of the magnets 7a and 7b of the two sputtering units 10a and 10b used for the two-magnet swing control. The magnet 7a of the first sputter unit 10a starts to move first and continues to move in a cycle of 9 seconds. Here, the magnet 7b of the second sputter unit 10b starts to move after 5 seconds, and continues to move in the same manner at a period of 9 seconds. Thus, the magnets 7a and 7b of the sputter units 10a and 10b continue to move at different times as described above. The time for shifting is determined according to the conveyance speed of the substrate 1. The time lag will be described later.

The movement of the magnet 7 in the two-magnet swing control will be further described. First, the concept for making the film thickness in the transport direction on the substrate uniform in this embodiment will be described.
The magnet 7 of the sputter unit 10 reciprocates with respect to the cathode center position, and the substrate moves at a constant speed (constant speed) in the transport direction. However, in order to explain the relationship between the film thickness on the substrate and the speed of the magnet 7, FIG. FIG. 8 is a schematic diagram of the relative speed Vms (upper side) of the magnet 7 relative to the substrate 1 and the relationship (lower side) between the relative speed Vms of the magnet 7 and the film thickness in the two-magnet swing control. In both the upper and lower sides of FIG. 8, the horizontal axis is the position on the substrate in the substrate transport direction. In the sputtering apparatus 100, the substrate is transported at a constant speed from the left to the right on the paper surface of FIG. Move while changing speed from left to right. The relative speed Vms of the magnet 7 with respect to the substrate 1 is positive in the right direction in FIG.

  A region A in FIG. 8 represents a range in which the magnet 7 moves in the negative direction with respect to the cathode 6, and the relative speed of the magnet 7 with respect to the substrate 1 is a relatively fast region. Region B is a range in which the magnet 7 moves in the positive direction with respect to the cathode 6, and the relative speed of the magnet 7 with respect to the substrate 1 is a relatively slow region. Regions A ′ and B ′ indicate a range where the magnet 7 is stopped. The sum of each range (A + A ′ + B + B ′) represents the distance that the substrate 1 moves relative to the magnet 7 while the magnet 7 reciprocates in one cycle.

  On the substrate, a relatively thin film is deposited for the range corresponding to the region A where the relative speed of the magnet 7 is fast, and a relatively thick film is deposited for the range corresponding to the region B where the relative speed of the magnet is slow. accumulate. This is because the amount of sputtered atoms emitted from the target 4 (4a or 4b) is constant because the DC power supplied to the cathode 6 is constant, and the sputtered atom emission position corresponds to the position of the magnet 7. by. Accordingly, a film thickness inversely proportional to the relative speed of the magnet 7 with respect to the substrate 1 is deposited on the substrate.

  However, the film thickness change on the substrate does not change abruptly like the change in the relative speed of the magnet 7 with respect to the substrate 1, but changes gently as shown in the lower part of FIG. This is because the emission position of the sputtered atoms emitted from the target 4 is emitted with a gentle distribution from the region of the width of the magnet 7 and the sputtered atoms fly over the distance between the target 4 and the substrate. This is because it spreads to some extent. What is important here is that the moving speed of the magnet 7 is set so that the lengths in the substrate transport direction in which the films are formed in the regions A and B are the same on the substrate. Further, the lengths in the substrate transport direction in which the films are formed in the regions A ′ and B ′ are also the same. By making the length of the film formed on the substrate the same, it is possible to overlap the film stacked by the film formation of another sputtering unit 10. As will be described later, it is possible to improve the film thickness distribution in a state where both the film formation by the pair of sputter units 10a and 10b has been completed.

FIG. 9 shows the relative speed V _ms with respect to the substrate divided into upper and lower parts for each of the magnets 7a and 7b. The horizontal axis positions on the substrate are aligned in the upper and lower graphs. The relative speed Vms of the magnet 7a of the first sputter unit 10a is the same as in FIG. The magnet 7b of the second sputter unit 10b repeats the same movement while being shifted by a distance of A + A ′ at a position on the substrate with respect to the movement of the magnet 7a of the first sputter unit 10a.

  Looking at the region A in FIG. 9, the relative speed of the magnet 7a of the first sputter unit 10a is relatively fast, and the relative speed of the magnet 7b of the second sputter unit 10b is relatively slow. In the region B, the relative speed of the magnet 7b of the second sputter unit 10b is relatively fast, and the relative speed of the magnet 7a of the first sputter unit 10a is relatively slow. When the film forming process is performed at such a relative speed of the magnets 7a and 7b, a relatively thin film is formed once and a relatively thick film is formed once in each region. Accordingly, in each of the regions A and B, the film thickness laminated by the two sputter units 10a and 10b is the same.

  As described above, the magnet 7 is moving at a constant speed with respect to the cathode 6 and the relative speed is constant. In each of the areas A and B, the acceleration area and the deceleration area of the magnet 7 exist at both ends of each area. When this part is also considered by the two sputter units 10a and 10b, one region having a relatively high relative speed and one region having a relatively low relative speed are controlled so as to overlap at a position on the same substrate. For this reason, the film thickness laminated | stacked by the two sputter | spatter units 10a and 10b in each area | region of A and B including this acceleration and deceleration part becomes the same.

  Further, the regions A ′ and B ′ of FIG. 9 where the film is formed while the magnet 7 is stopped with respect to the cathode 6 will be described. The film thickness here is intermediate between the film thicknesses formed in the regions A and B described above. Since the film thicknesses in the regions A ′ and B ′ are the same, when they are stacked on the substrate, the film thicknesses are the same as those stacked in the regions A and B. That is, the film thicknesses stacked in the regions A, B, A ′, and B ′ are all the same.

The following is a summary of the concept of magnet control in the two-magnet swing control.
(A) The length on the board | substrate formed into a film in area | region A and B is made the same.
(B) The lengths on the substrates formed in the regions A ′ and B ′ are made the same.
(C) The movements of the magnets 7a and 7b of the two sputtering units 10a and 10b are shifted in the substrate transport direction by the length of the region A + A ′ on the substrate.

Until now, it has been assumed that the forward speed Vf of the magnet 7 is smaller than the substrate transport speed Vt, that is, the magnet 7 does not overtake the substrate 1. When this condition is satisfied, the magnet operation of the two-magnet swing control can be applied. As described above, in order to obtain a uniform film thickness distribution by film formation with two-magnet swing control, it is necessary to satisfy the following film formation conditions.

Here, T is the period of reciprocation of the magnet 7 (unit: second), Tsew is the stop time of the magnet 7, Tacc is the average of the acceleration time Tacc1 and the deceleration time Tacc2, L is the stroke (one way), and Vt is the substrate transfer speed. It is.

  FIG. 10 shows an example of film formation by 2-magnet swing control. In FIG. 10, the film thickness on the substrate by each of the sputter units 10a and 10b is represented by two lines (broken line and thin solid line). Each film thickness appears alternately in relatively thick regions and thin regions. The period of film thickness change on each substrate is Vt · T = 300 mm. These are deposited as a film with a shift of 150 mm on the substrate. The upper thick line is the film thickness laminated by the two sputter units 10a and 10b, and is the sum of the lower two film thicknesses. The laminated film thickness is almost uniform. In this example, the film thickness distribution was ± 0.03%.

Here, a method for selecting a control method will be described.
FIG. 11 shows the range of the period T that can be taken with respect to the substrate transfer speed Vt for the simple swing control and the two-magnet swing control. The range that can be taken by the period T is a range of a period that has no theoretical inconvenience in the operation of the magnet 7 and satisfies at least that the film thickness in the substrate transport direction is uniform. The range below the lower curve of the two curves shown in FIG. 11 is a range in which the film thickness in the substrate transport direction can be made uniform by simple swing control. In this range, the above formula (1) is satisfied.

  The range that the period T can take is below the curve that is inversely proportional to the conveyance speed Vt. For example, when the conveyance speed Vt is 33.33 mm / s, the period T needs to be smaller than 2.1 seconds. The range above the upper curve of the two curves shown in FIG. 11 is a range in which the film thickness in the transport direction can be made uniform without any theoretical inconvenience in the operation of the magnet by the two-magnet swing control. In this range, the above equation (2) is satisfied.

  When the acceleration / deceleration time Tacc of the magnet 7 and the magnet stop time Tsew at the stroke end are small, the range that the period T can take is above the curve that is almost inversely proportional to the conveyance speed Vt. For example, when the transport speed Vt is 33.33 mm / s, Tacc is 0.3 seconds, and Tsew is 0.4 seconds, the cycle T needs to be greater than 8.0 seconds. Note that if the period T is set to a value close to a curve in the two-magnet swing control, the speed of the magnet 7 becomes very fast, so it is actually preferable to select a period slightly above the curve, that is, a slightly larger period. For example, when the cycle T is 8.0 seconds, the constant velocity Vb in the reverse direction is as high as 333.3 mm / s at the stroke L = 100 mm, but when the cycle T is 9 seconds, Vb is significantly as 125 mm / s. Can be small.

  As described above, when the substrate transport speed Vt is determined, the possible range of the period T is determined to be the range shown in FIG. In the apparatus of the present embodiment, the range of the period T has no overlapping area between the simple swing control and the two-magnet swing control. Accordingly, when the substrate transport speed Vt is determined, either the simple swing control or the two-magnet swing control is selected, and the period T that can be set for each is determined.

  In addition, when using the metal target which hardly generates a nodule for the target 4 like this embodiment, it may be better to further limit the period T. That is, as can be seen from FIG. 11, when the transport speed Vt is slow, the period T of the moving speed of the two-magnet swing control magnet must be extremely increased. When the period is large, the moving speed of the magnet is slow, so that a region that is not sputtered for a relatively long time is generated on the target surface. A reattached film is deposited on the surface of the target that is not sputtered, and the material reattached when the region is sputtered is simultaneously sputtered and deposited on the substrate. For this reason, since the film deposited on the substrate 1 may have a large amount of impurities, it is preferable not to make the period T of the reciprocating magnet movement below a certain level. Generally, there is no problem in film quality if the period T is 20 seconds or less. Further, since the output of the magnet drive device 11 is finite, the cycle T has a lower limit value. In general, the period T is preferably set to 3 seconds or more.

  The substrate transport speed Vt is generally determined by the apparatus configuration and the required film thickness. Which control method is selected is determined as follows. FIG. 12 is a schematic diagram summarizing the range that the period T can take. When the conveyance speed Vt is about 11 mm / s or less, the two-magnet swing control cannot be selected as shown in FIG. Therefore, an appropriate cycle T is selected from the range shown in FIG. When the transport speed Vt is about 23 mm / s or more, the simple swing control cannot be selected as shown in FIG. Therefore, an appropriate period T is selected from the range shown in FIG. When the conveyance speed Vt is between about 11 mm / s and 23 mm / s, an appropriate cycle T can be selected by either simple swing control or two-magnet swing control. Which control method is selected in the range of the conveyance speed is comprehensively determined by other factors.

  As described above, when the substrate transport speed Vt is given, an appropriate magnet swing method is selected from the simple swing control or the two-magnet swing control from FIG. The control selection unit 25 selects either a simple swing control method or a two-magnet swing control method. A storage unit 27 that stores data for selecting a control method is connected to the control selection unit 25 (see FIG. 1). The control selection unit 25 has a program for selecting a control method capable of obtaining a more uniform film thickness distribution with reference to the substrate conveyance speed and the data in the storage unit 27. The substrate transfer speed is input from the transfer control device 21 connected to the control selection unit 25. The storage unit 27 of the present embodiment stores data having the contents shown in FIG. Note that the storage unit 27 may be provided in the control selection unit 25 or may be provided outside the sputtering apparatus. The program in the control selection unit 25 determines the optimum period T with reference to the data in the storage unit 27.

A program for selecting a control method will be described with reference to FIG.
In the first embodiment using the two sputter units 10a and 10b, if the substrate transport speed Vt is given, the selection of an appropriate control method and the period T of the magnet reciprocation can be selected from FIG. However, the period T cannot be uniquely determined by the period T that can be selected by either control method. Therefore, in the present embodiment, any one is preferentially selected. For example, it can be set to preferentially select a control method of simple swing control in which the operation of the magnet 7 is simple.

  When the control method of the simple swing control is selected, the period T as small as possible can be used in a wide range of the substrate transport speed Vt. The minimum value (for example, T = 3 seconds) can be used as the period T in the control method of the simple oscillation control. When the control method of the two-magnet swing control is selected, the period T that is as large as possible can be used in a wide range of the substrate transport speed Vt. The period T in the control method of the two-magnet swing control can be a maximum value (for example, T = 20 seconds).

  The flowchart of FIG. 13 is based on the above-described concept. The selection of the magnet control method is performed by the control selection unit 25. That is, the control selection unit 25 reads the substrate transport speed Vt (step 1). When the substrate transport speed Vt is 23 mm / s or less, the control method of simple swing control is selected, and the period T is set to 3 seconds (step 2). When the substrate transport speed Vt is greater than 23 mm / s, the control method of 2-magnet swing control is selected, and the cycle T is set to 20 seconds (step 3).

  In addition, 23 mm / s of the board | substrate conveyance speed Vt used here is obtained by combining (1) Formula and (2) Formula. As described above, the control selection unit 25 can calculate and select an appropriate control method and determine the magnet reciprocation period T. The control method selected by the control selection unit 25 is executed by the magnet drive device 11 and the transport control device 21. As a result, sputter film formation is possible by controlling the magnet 7 with an appropriate magnet driving device 11 for any substrate transfer speed Vt, and film formation with a uniform film thickness at least in the substrate transfer direction is possible.

(Second Embodiment)
A sputtering apparatus that automatically switches the control method of the three sputtering units according to the second embodiment of the present invention will be described with reference to the drawings. With the control method of “2 magnet swing control” described above, it is difficult to form a uniform film in the transport direction when the number of sputtering units 10 used in the film forming process is an odd number. Therefore, a method for improving the film thickness distribution that can be applied to the case where three sputtering units 10 are used at a conveyance speed at which the control method of “simple swing control” cannot be selected will be described below.

  FIG. 14 is a schematic cross-sectional view for explaining the film formation chamber configuration of the substrate transfer type in-line continuous sputter film forming apparatus (sputtering apparatus 101) of the second embodiment. In the first embodiment, the number of sputter units 10 used is two, but in the second embodiment, the number of sputter units 10 used is three. The three sputter units 10 are first, second, and third sputter units (10a, 10b, 10c) in order from the upstream side in the substrate transport direction. Each sputter unit 10 has the same configuration as that of the first embodiment. There are two types of magnet control methods that can be selected in this embodiment: simple swing control and three-magnet swing control. The configuration in which either one is selected by the control selection unit 25 is the same as in the first embodiment. In addition, although the sputtering apparatus 101 is drawn as the structure which added the sputtering unit 10c to the sputtering apparatus 100 of 1st Embodiment, you may provide four or more sputtering units.

  The simple swing control is to perform simple swing control of each of the three magnets, and since it is the same as the movement of the magnet 7 in the first embodiment described above, detailed description thereof is omitted. The 3-magnet swing control is different from the above-described 2-magnet control method in that the magnet moves. The control method of the three-magnet swing control is to operate the three magnets and the substrate transport device in conjunction with each other to make the film thickness in the transport direction uniform. Hereinafter, a sputtering film forming method using three-magnet swing control will be described.

  FIG. 15 shows an example of the movement of the magnet in the three-magnet swing control, and FIG. 16 shows a velocity diagram of the magnet at that time. Schematic diagrams of the positional relationship between the magnet 7 and the substrate at this time are shown in FIGS. In this example, the stroke L (one way) of the reciprocating movement of the magnet 7 is 100 mm, and the period T of the reciprocating movement is 9 seconds. The vertical axis of the graph of FIG. 15 is the substrate transfer position, the position where the center position of the magnet 7 overlaps the center position of the cathode 6 is 0 mm, and the forward direction which is the substrate transfer direction is positive and the reverse direction is negative. ing. The initial position of the magnet 7 is a +50 mm position (indicated by P0 in FIGS. 15-17) which is the stroke end in the forward direction. Starting from here, the magnet 7 moves in the reverse direction and stops once at the 0 mm position (first predetermined position) (indicated by P1 in FIGS. 15-17) which is the center of the stroke. The movement so far is referred to as a first movement (see FIG. 17A). A film formed on the substrate during the first movement during film formation is referred to as a first film.

  After the first movement, it moves again in the reverse direction, moves to the opposite stroke end of −50 mm (second predetermined position) (indicated by P2 in FIGS. 15-17) and stops again. This movement is referred to as a second movement (see FIG. 17B). A film formed on the substrate during the second movement at the time of film formation is referred to as a second film. Next, the magnet 7 moves in the forward direction in the opposite direction, and moves to the +50 mm position (third predetermined position, indicated by P3 in FIGS. 15-17), which is the stroke end in the forward direction, and stops. This movement is called a third movement (see FIG. 17C). During film formation, a film formed on the substrate during the third movement is referred to as a third film. Up to this point, 9 seconds are required for one cycle. The position (P3) where the magnet 7 stops after the third movement is the start position (P0) of the first movement. The magnet 7 repeats the first to third movements at a predetermined cycle (T = 9 seconds in this embodiment). The time for stopping during the first, second and third movements is equal.

FIG. 16 is a velocity diagram showing a velocity change for one cycle of the movement of the magnet of FIG. The horizontal axis represents time, and the vertical axis represents the velocity V _mc of the magnet with respect to the cathode. The direction of the velocity is positive in the forward direction, which is the substrate transport direction, and negative in the reverse direction. Moreover, the code | symbol (P0-P3) corresponding to the position in FIG. 15 was described in the position where the magnet 7 stops (speed is zero) in FIG. The magnet 7 is accelerated at a constant acceleration in the reverse direction from the initial position (position P0), then moves at the constant speed in the reverse direction, then decelerates at the constant acceleration in the reverse direction, the speed becomes zero, and stops at the position P1. . The shape of the velocity diagram so far shows a trapezoid. In this embodiment, speed control generally referred to as trapezoidal drive (trapezoid control) is employed. This is a general method for controlling motor drive. By the speed control so far, the magnet has moved from the +50 mm position at the stroke end in the forward direction of the initial position (position P0) shown in FIG. 15 to the 0 mm position (first predetermined position, position P1) at the stroke center. After that, the speed is kept at 0 mm / s because the motor stops for a certain time. This is the first movement.

  Next, the trapezoidal driving and stopping in the reverse direction, constant speed, and deceleration are repeated in the same manner as the speed change so far. Up to this point, it has moved from the stroke end in the reverse direction shown in FIG. 15 to the −50 mm position (second predetermined position, position P2). The second movement is from the 0 mm position to the −50 mm position at the center of the stroke. Next, trapezoidal drive and stop (third predetermined position, position P3) of acceleration, constant speed, and deceleration are performed in the forward direction (positive speed in FIG. 16). However, the forward speed and the constant speed are different from those in the reverse direction. The absolute value of the constant speed becomes smaller than the reverse direction, and the constant speed time becomes longer. The third movement is from the −50 mm position to the +50 mm position at the center of the stroke. In the present embodiment, the position (position P3) where the third movement is completed coincides with the start position (position P0) of the first movement.

  Up to this point, an example of the movement of the magnet 7 of any one sputter unit 10 has been shown, but FIG. 18 shows an example of the movement of the magnets 7a, 7b, 7c of the three sputter units 10a, 10b, 10c. The magnet 7a of the first sputter unit 10a starts to move first and continues to move in a cycle of 9 seconds. Here, the magnet 7b of the second sputter unit 10b starts to move with a delay of 5 seconds and continues to move in the same manner with a period of 9 seconds. Further, the magnet 7c of the third sputter unit 10c starts to move after 10 seconds and continues to move in the same manner at a cycle of 9 seconds. In this way, the magnets 7 of the respective sputter units 10 continue to move at different times. The time lag when the magnets 7b and 7c start moving will be described later.

  Next, the control of the movement of the magnet 7 during the three-magnet swing control will be described. First, the concept for making the film thickness in the transport direction on the substrate uniform in this embodiment will be described. The magnet 7 of the sputter unit 10 reciprocates around the center position of the cathode 6 in the transport direction. On the other hand, the substrate 1 is also moved at a constant speed (constant speed) in the transport direction while the magnet 7 is reciprocating. FIG. 19 is a schematic diagram showing the relative speed and film thickness of the magnet 7 with respect to the substrate to be transported for any one sputter unit 10.

FIG. 19 is a schematic diagram for explaining the relationship between the film thickness on the substrate and the speed of the magnet 7. The upper part of FIG. 19 shows the relative speed of the magnet 7 with respect to the substrate of the magnet 7 with respect to the substrate. It is expressed as a relative speed V _ms , and the lower part of FIG. 19 schematically shows the film thickness formed at a position on the substrate corresponding to the upper horizontal axis. The horizontal axis in FIG. 19 is the position on the substrate in the substrate transport direction. In the actual sputtering film forming apparatus, the substrate is conveyed at a constant speed from the right to the left on the paper surface of FIG. 19, and the magnet 7 is fixed to the substrate for convenience sake. Always move from left to right while changing speed. The relative speed V _ms of the magnet 7 with respect to the substrate is graphed with the right direction being positive in FIG.

  The range of A and B described in FIG. 19 represents the range in which the magnet 7 is moving in the direction opposite to the substrate transport direction, and the relative speed of the magnet 7 with respect to the substrate is a relatively fast region. A range C represents a range in which the magnet 7 is moving in the substrate transport direction (forward direction), and the relative speed of the magnet 7 to the substrate is a relatively slow region. A ′, B ′, and C ′ indicate areas where the magnet 7 is stopped. The sum of each range, A + A ′ + B + B ′ + C + C ′, represents the distance that the substrate 1 travels while the magnet 7 reciprocates for one cycle.

  A relatively thin film is deposited on the area corresponding to A and B in FIG. 19, and a relatively thick film is deposited on the area corresponding to C in FIG. 19 (see the lower side of FIG. 19). ). This is because the DC power supplied to the cathode 6 is constant, so that the density of sputtered atoms emitted from the target 4 is constant, and the sputtered atom emission position corresponds to the position of the magnet 7. Therefore, a film thickness inversely proportional to the relative speed of the magnet 7 with respect to the substrate is deposited on the substrate.

  However, the film thickness change on the substrate does not change abruptly like the change in the relative speed of the magnet 7 with respect to the substrate, but changes gently as shown in the lower diagram of FIG. This is because the sputtered atoms emitted from the target 4 are sputtered from a region about the width of the magnet 7, so that the distribution of the sputtered atoms is gentle and the distance between the target 4 and the substrate is determined by the sputtered atoms. This is because it spreads to some extent while flying.

  What is important here is that the moving speed of the magnet 7 with respect to the cathode and the transport speed of the substrate so that the lengths in the transport direction of the substrate formed on the substrate corresponding to the ranges A, B, and C are the same. Is being adjusted. Further, the distances in the substrate transport direction in which films are formed on the substrate corresponding to the ranges A ′, B ′, and C ′ are the same. By making the film formation length (distance in the substrate transfer direction) the same, the film thickness after being deposited by the film formation by the second and third sputtering units, which will be described later, is made uniform in the transfer direction. Can do.

FIG. 20 shows the relative speed V _ms of the magnet 7 with respect to the substrate when the magnets 7 of the three sputter units are viewed with respect to the substrate. The position on the substrate on the horizontal axis is shown in three graphs. The relative speed V _ms of the magnet 7a of the first sputter unit 10a is the same as in FIG. The magnet 7b of the second sputter unit 10b is moved repeatedly in the same manner while being shifted from the magnet 7a of the first sputter unit 10a by a distance of A + A ′ at a position on the substrate. The magnet 7c of the third sputter unit 10c is repeatedly moved at the position on the substrate by a distance of A + A ′ + B + B ′ with respect to the movement of the magnet 7a of the first sputter unit 10a. In other words, the magnet 7 is repeatedly moved at a predetermined cycle. When the substrate is used as a reference, the magnet 7b is shifted by a third cycle in an arbitrary direction with respect to the magnet 7a, and the magnet 7c is moved to the magnet 7a. On the other hand, there is a shift of 2/3 period in one direction (or 1/3 period in the reverse direction).

  In this way, the region (region A) on the substrate corresponding to region A in FIG. 20 is formed in the first sputtering unit 10a with the relative speed between the magnet 7a and the substrate being relatively high, and the second In the sputtering unit 10b, the film is formed with a relatively low relative speed between the magnet 7b and the substrate, and in the third sputtering unit 10c, the film is formed with a relatively high relative speed between the magnet 7c and the substrate. Similarly, in the regions B and C in FIG. 20, two of the three sputter units form a film with a relatively high relative speed with the magnet, and one with a relatively slow relative speed of the magnet. A film is to be formed. When the film is formed at such a relative speed of the magnet 7, a relatively thin film is formed twice and a relatively thick film is formed once in each region. Accordingly, in each of the regions A, B, and C, the film thickness laminated by the three sputter units is the same.

  In the above description, the magnet 7 is moving at a constant speed with respect to the cathode 6 and the relative speed is constant. In each of the areas A, B, and C, the acceleration area and the deceleration area of the magnet exist at both ends of each area. When this part is also considered with three sputter units, two regions having a relatively high relative speed and one region having a relatively low relative speed overlap at a position on the same substrate. For this reason, the film thickness laminated | stacked by the three sputter | spatter units in each area | region of A, B, and C also including the part of this acceleration area | region and a deceleration area | region becomes the same.

  Next, the regions A ′, B ′, and C ′ of FIG. 20 where the film is formed while the magnet 7 is stopped with respect to the cathode 6 will be described. The film thickness in the regions A ′, B ′, and C ′ is the film thickness (relative to the film thickness formed on the substrate when the magnet 7 in the regions A, B, and C described above is moving in the substrate transport direction. The film thickness is intermediate between the thick film thickness) and the film thickness (relatively thin film thickness) formed on the substrate when the magnet 7 moves in the opposite direction. Of course, the film thicknesses formed on the substrate are the same in the regions A ′, B ′, and C ′. In the three sputter units, the regions A ′, B ′, and C ′ are laminated on the substrate with the same film thickness. By controlling with the movement of the magnet 7 obtained by the calculation formula described later, the film thickness laminated in three layers through the regions A ′, B ′, C ′ passes through the regions A, B, C. It is known that the film thickness is the same as the thickness of the three layers.

  The above is the concept of the film forming method and the film forming apparatus control method of the present embodiment. That is, the lengths on the substrate on which films are formed in the regions A, B, and C are made the same. The lengths on the substrate on which films are formed in the regions A ′, B ′, and C ′ are made the same. The movements (phases) of the magnets 7 of the three sputtering units are shifted so that the film formation position on the substrate advances by the length of film formation in the region of A + A ′ on the substrate.

  More specifically, during film formation, a first film formed on the substrate during the first movement, and a second film formed on the substrate during the second movement; The third film formed on the substrate during the third movement is performed by a magnetron sputtering unit (target) different from the third film. At this time, by adjusting the substrate transport speed and the movement timing of the magnet 7, the first film formed from one target, the second film formed from another target, and the remaining target are formed. The film is formed so as to overlap with the formed third film. And it controls so that the deposited part may overlap on a board | substrate when the magnet 7 has stopped by each of the 1st, 2nd, 3rd movement. By such a film formation method, a film having a uniform thickness is formed on the substrate after passing through the front surfaces (lower sides) of the three targets 4a, 4b, and 4c in the film formation chamber 100.

Similarly to the 2-magnet swing control, the 3-magnet swing control is based on the premise that the forward velocity Vf of the magnet is smaller than the substrate transport speed Vt, that is, the magnet does not overtake the substrate. In order to satisfy this condition, the following expression holds for the period T.
Here, Tsew is the magnet stop time, Tacc is the average of the acceleration time Tacc1 and the deceleration time Tacc2, and L is the stroke of the magnet reciprocation.

  A selection method of two methods, that is, a control method of simple swing control and three magnet swing control in the control selection unit 25 will be described. FIG. 21 shows the range of the period T that can be taken with respect to the substrate transport speed Vt for simple swing control and three-magnet swing control. The range of the period T that can be taken is a range in which there is no theoretical inconvenience in the operation of the magnet and the film thickness in the substrate transport direction can be made uniform. In the range below the lower curve of the two curves in FIG. 21, the film thickness in the substrate transport direction can be made uniform by simple swing control. In this range, the expression (1) is satisfied. The range that the period T can take is below the curve that is inversely proportional to the conveyance speed Vt.

  The range above the upper curve of the two curves in FIG. 21 has no theoretical inconvenience in the operation of the magnet by the three-magnet swing control, and the film thickness in the transport direction can be made uniform. The range that the period T can take in the three-magnet swing control is above the curve that is almost inversely proportional to the transport speed Vt when the acceleration / deceleration time Tacc of the magnet 7 and the magnet stop time Tsew are small. For example, when the conveyance speed Vt is 33.33 mm / s, Tacc is 0.3 seconds, and Tsew is 0.4 seconds, the period T needs to be greater than 7.5 seconds.

  However, in the three-magnet swing control, if the period T is set near a curve, the speed of the magnet 7 becomes very fast, so in practice, a slightly higher period than the curve, that is, a slightly larger period is selected. For example, when the conveyance speed Vt = 33.33 mm / s, the period 7.5 seconds is the lower limit. At this time, when the stroke L = 100 mm, the constant speed Vb in the reverse direction is 166.7 mm / s, but the period T Is 8.5 seconds, Vb can be greatly reduced to 78.95 mm / s.

  Thus, when the substrate transport speed Vt is determined, the range that the period T can take can be set to the range shown in FIG. In the apparatus of the present embodiment, the possible range of the period T does not overlap with each other in the simple swing control and the three-magnet swing control. Therefore, when the substrate transport speed Vt is determined, either the simple swing control or the 3-magnet swing control is selected, and the allowable period T is determined. As described in the first embodiment, the period T is preferably 20 seconds or less and 3 seconds or more.

  The substrate transport speed Vt is generally determined by the apparatus configuration and the required film thickness. Which magnet swing method is selected is determined as follows. FIG. 22 shows a schematic diagram summarizing the range that the period T can take. When the transport speed Vt is about 9 mm / s or less, the three-magnet swing control cannot be selected as shown in FIG. Therefore, an appropriate cycle T is selected from the range shown in FIG. When the conveyance speed Vt is about 23 mm / s or more, the simple swing control cannot be selected as shown in FIG. Accordingly, an appropriate period T is selected from FIG. When Vt is approximately 9 mm / s to 23 mm / s at the conveyance speed, an appropriate cycle T can be selected by either simple swing control or 3-magnet swing control. Which control method is selected in the range of the conveyance speed is comprehensively determined by other factors.

  As described above, when the substrate transport speed Vt is given, an appropriate magnet swing method is selected from the simple swing control or the three-magnet swing control from FIG. The 3-magnet swing control is selected when the speed is equal to or higher than a predetermined substrate transfer speed (a predetermined speed or higher). The period T of the magnet reciprocation at this time is set to an appropriate value from FIG. A storage unit 27 that stores data for selecting a control method is connected to the control selection unit 25 (see FIG. 1). The control selection unit 25 has a program for selecting a control method capable of obtaining a more uniform film thickness distribution with reference to the substrate conveyance speed and the data in the storage unit 27. The substrate transfer speed is input from the transfer control device 21 connected to the control selection unit 25. The storage unit 27 of the present embodiment stores data having the contents shown in FIG. Note that the storage unit 27 may be provided in the control selection unit 25 or may be provided outside the sputtering apparatus. The program in the control selection unit 25 determines the optimum period T with reference to the data in the storage unit 27.

A program for selecting a control method will be described with reference to FIG.
In the second embodiment using three sputter units 10a, 10b, and 10c, selection of an appropriate magnet control method and period T of magnet reciprocation can be selected from FIG. However, the period T cannot be uniquely determined by the period T that can be selected by either control method. Therefore, in the present embodiment, any one is preferentially selected. For example, it can be set to preferentially select a control method of simple swing control in which the operation of the magnet 7 is simple.

  When the control method of the simple swing control is selected, the period T as small as possible can be used in a wide range of the substrate transport speed Vt. The minimum value (for example, T = 3 seconds) can be used as the period T in the control method of the simple oscillation control. When the control method of the three-magnet swing control is selected, the period T that is as large as possible can be used in a wide range of the substrate transport speed Vt. The period T in the control method of the three-magnet swing control can be a maximum value (for example, T = 20 seconds).

  The flowchart in FIG. 23 is based on the above concept. The selection of the magnet control method is performed by the control selection unit 25. That is, the control selection unit 25 reads the substrate transport speed Vt (step 10). When the substrate transport speed Vt is 23 mm / s or less, the control method of simple swing control is selected, and the period T is set to 3 seconds (step 11). When the substrate transport speed Vt is greater than 23 mm / s, the control method of 3 magnet swing control is selected, and the cycle T is set to 20 seconds (step 12).

  In addition, 23 mm / s of the board | substrate conveyance speed Vt used here is obtained by combining (1) Formula and (3) Formula. As described above, the control selection unit 25 can calculate and select an appropriate control method and determine the magnet reciprocation period T. The control method selected by the control selection unit 25 is executed by the magnet drive device 11 and the transport control device 21. As a result, the sputter film is formed by controlling the magnet 7 (magnet driving device 11) with the appropriate magnet controller 22 for any substrate transport speed Vt, and at least a uniform film thickness is formed in the substrate transport direction. A membrane is possible.

Next, selection by the control selection unit 25 when using five or more sputtering units will be described. In particular, when an odd number of five or more sputter units are used, the magnet control method (method) is selected by combining the two embodiments described above. As a specific example, a case where seven sputter units are used in a sputter deposition apparatus will be described.
In this case, the seven sputter units are divided into two groups (second group) having two sputter units and one group (first group) having three sputter units. That is, in the group having two sputter units (second group), an appropriate one is selected from the two control methods of simple swing control and 2-magnet swing control based on the first embodiment described above. There are two groups having two, but each can determine the control method. On the other hand, in a group (first group) having three sputter units, an appropriate one is selected from the two control methods of simple swing control and three-magnet swing control based on the second embodiment described above. According to this method, the film thickness distribution can be made uniform in each group.

  Further, according to this method, even if the number of sputtering units used for film formation changes, it is possible to ensure the uniformity of the film thickness distribution by simply switching the control method with the control selection unit 25. Therefore, it is possible to quickly cope with a change in the film forming process. A program for selecting a control method when using five or more sputtering units is input to the control selection unit 25 as in the above-described embodiment. The number of sputtering units to be used can be input to the control selection unit 25 from a controller in which a film forming process is input from an operator or from an external input device such as a keyboard or a push button.

  By combining the sputtering method consisting of two sputter units of the first embodiment and the sputtering method consisting of three sputter units of the second embodiment, the transport direction is also used in sputtering film formation using five or more sputter units. Uniform film formation. When using an arbitrary number N (N is 5 or more) of sputter units, the group X group having three sputter units and the group Y group having two sputter units are considered, and the film thickness distribution is uniform in each group. By selecting a control method that can secure the property, it is possible to obtain a final film thickness distribution. For example, in the case of using seven sputter units as described above, it is considered to be a combination of two groups having two sputter units and one group having three sputter units. The film thickness distribution can be made uniform.

Based on FIG. 24, a program for grouping when using an arbitrary number of sputtering units will be described.
The flowchart of FIG. 24 is based on the above concept. That is, the N sputter units used are divided into X groups having three sputter units and Y groups having two sputter units, and the group having two sputter units is shown in the flowchart of FIG. The group having three sputter units selects the control method according to the flowchart of FIG. At this time, the relationship of 3X + 2Y = N is satisfied.

  The grouping of an arbitrary number of sputtering units is performed by the control selection unit 25. That is, the number N of sputter units used by the control selection unit 25 is read (step 20). If the number N of sputter units to be used is an even number, it is determined that there are N / 2 sets of groups having two sputter units (step 21: Yes). On the other hand, if the number N of sputter units to be used is an odd number, it is determined that there are one set of groups having three sputter units and (N−3) / 2 sets of groups having two sputter units. Thereafter, for the group having two sputter units, the process jumps to step 1 of FIG. 13 described above, and the control method is selected according to the flowchart of FIG. Further, for the group having three sputter units, the control method is selected in accordance with the flowchart of FIG. 23 by jumping to step 10 of FIG. 23 described above.

  In the present embodiment, when the number of sputtering units to be used is an even number of 4 or more (step 21: Yes), the control method (method) selected based on the first embodiment is a plurality of the first control methods. Implemented in two groups. However, when the number of sputter units used is an even number that is a multiple of 3, the control method (method) for controlling the magnet selected based on the second embodiment is implemented in the plurality of first groups. May be. For example, when the number of sputtering units used is 10, it is of course possible to select a control method (method) for controlling the magnets by dividing into two groups of the second group and two groups of the first group. It is.

  The sputtering apparatus according to the present invention can be easily changed to a control method capable of obtaining a good film thickness distribution. In particular, when performing multiple types of film formation with the same sputtering apparatus, it can be easily changed to a control method that can obtain the most uniform film thickness at the transport speed of the film formation process and the number of targets used, A sputtering apparatus suitable for manufacturing a wide variety of products can be provided.

1 substrate 2 chamber (vacuum container)
3 Substrate transport roller 4 Target 5 Target shield 6 Cathode 7 Magnet (magnet part)
8 Cathode insulating part 9 Cathode partition (target holding part)
10 Sputter Unit 11 Magnet Drive Device (Magnet Drive Unit)
21 Transport control device 22 Magnet control device 25 Control selection unit (selection unit)
27 Storage unit 100, 101 Sputtering apparatus

Claims (8)

A vacuum vessel;
A substrate transport unit for transporting the substrate in the vacuum container;
At least three target holding units arranged in the transfer direction of the substrate to hold targets for film formation sequentially on the substrate transferred by the substrate transfer unit;
A magnet portion disposed on the back side of each of the target holding portions;
A magnet drive unit for driving the magnet unit;
When performing the film forming process by holding the target in the target holding unit, the method is more uniform from among a plurality of methods for controlling the magnet driving unit according to the transport speed of the substrate and the number of targets used. And a selection unit that selects a method for obtaining a film thickness distribution.   The selection unit is configured such that when the transport speed is equal to or higher than a predetermined speed and the number of targets to be used is an odd number of 5 or more, the target to be used is a first group including three targets. Are divided into X groups and a second group having two targets into Y groups so as to satisfy the formula (3X + 2Y = N), and different methods are selected for each of the first group and the second group. The sputtering apparatus according to claim 1.   The sputtering apparatus according to claim 2, wherein X = 1. The storage unit is connected to the selection unit and stores a plurality of methods for controlling the magnet driving unit,
The method stored in the storage unit is:
A first movement for moving each magnet unit belonging to the first group from a stroke end in the conveyance direction in a direction opposite to the conveyance direction and stopping at a first predetermined position; and after the first movement A second movement to move in the reverse direction from the first predetermined position and stop at the second predetermined position; and a third movement to move from the stroke end in the reverse direction to the conveyance direction and stop at the stroke end in the conveyance direction. The movement of the substrate in a predetermined cycle, and in each of the first, second, and third movements, the distance that the substrate moves relative to the magnet portion in the transport direction becomes equal. The sputtering apparatus according to claim 2, further comprising:   The method stored in the storage unit is characterized in that the time during which the magnet unit is stopped is equal in each of the first movement, the second movement, and the third movement. The sputtering apparatus according to claim 4.   In the method stored in the storage unit, a portion of the first film, the second film, and the third film that is deposited while the magnet unit is stopped is on the substrate. The sputtering apparatus according to claim 5, which overlaps with each other.   7. The sputtering apparatus according to claim 4, wherein in the method stored in the storage unit, the second predetermined position is the stroke end in the reverse direction. The storage unit further includes
Each magnet unit belonging to the second group is moved from the stroke end in the transport direction to the stroke end opposite to the transport direction and stopped, and from the stroke end in the reverse direction to the transport direction. 5. The sputtering apparatus according to claim 4, further storing a method of executing movement at a predetermined cycle in order to move and stop at the stroke end in the transport direction. 6.