JP2012184479A - Sputtering apparatus and sputtering method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sputtering apparatus and a sputtering method, by which a thin film having a uniform thickness is formed on an end part of a substrate.SOLUTION: In the sputtering method, a plurality of long and thin shaped targets are arranged side by side in a vacuum chamber in such a manner that the longitudinal directions of the targets are mutually parallel while the faces to be sputtered are located in the same plane and the side faces of the targets face each other; and a thin film is formed on a substrate by setting adjacent two targets of the plurality of long and thin shaped targets as one set, and then sputtering the targets by applying an off-voltage to at least one target of a set of the targets and alternately applying an on-voltage and an off-voltage to two targets of the set of targets. The sets of targets are arranged in one line, and when an on-voltage and an off-voltage are applied to the targets, the time for applying an on-voltage to the target located on the end side of the one line is made longer than the time for applying an on-voltage to the other target, in the set of targets located at the end of the one line.

Description

  The present invention relates to a sputtering apparatus and a sputtering method.

  Currently, flat panel display technology has been developed and the market for flat-screen televisions has been established. In order to reduce the manufacturing and production costs of large televisions, the size of glass substrates has been increasing, and large-area glass substrates have been developed. There is a need for a technique for forming a thin film with a uniform film thickness.

FIG. 8 is an internal configuration diagram of a conventional sputtering apparatus 100. A conventional sputtering apparatus 100 includes a vacuum chamber 111, a plurality of elongated cathode electrodes 122 ₁ , 123 _{1 to} 122 _n , 123 _n disposed in the vacuum chamber 111, cathode electrodes 122 ₁ , 123 _{1 to} 122 _n , And targets 124 ₁ , 125 _{1 to} 124 _n , 125 _n arranged on 123 _n (hereinafter, n represents a natural number of 2 or more).

The cathode electrodes 122 ₁ , 123 _{1 to} 122 _n , 123 _n are parallel to each other in the longitudinal direction, and the targets 124 ₁ , 125 _{1 to} 124 _n , 125 _n on the cathode electrodes 122 ₁ , 123 _{1 to} 122 _n , 123 _n are arranged. The surfaces to be sputtered are located on the same plane and are arranged side by side so that the side surfaces of the adjacent targets 124 ₁ , 125 _{1 to} 124 _n and 125 _n face each other.
When two adjacent targets are set as target sets 121 _{1 to} 121 _n , the target sets 121 _{1 to} 121 _n are arranged in a line.

When voltages having opposite polarities are alternately applied to the two targets in one set of targets from the power supply devices 131 _{1 to} 131 _n via the cathode electrodes 122 ₁ , 123 _{1 to} 122 _n and 123 _n , Discharge occurs between the targets, the sputtering gas in the vacuum chamber 111 is turned into plasma, and ions in the plasma enter the target to which a negative voltage is applied to sputter the target. A negative voltage is alternately applied to two targets in a set of targets, and the two targets are alternately sputtered. The particles emitted from the target reach the substrate 141 to form a thin film.

When the application period of the negative voltage of each target 124 ₁ , 125 _{1 to} 124 _n , 125 _n is made the same and the magnitude of the application voltage is made the same, referring to FIG. A thin film having a uniform film thickness is formed in a range facing the target sets 121 _{2 to} 121 _n-1 located on the inner side (hereinafter referred to as a central region), but the target set 121 ₁ positioned at the end of the row, In a range facing 121 _n (hereinafter referred to as an end region), the closer to the end, the smaller the number of targets located in the vicinity, so that the amount of particles that reach is reduced and the thickness of the thin film is reduced. There was a problem.

In order to increase the film thickness of the end region, when the magnitude of the voltage applied to the target sets 121 ₁ , 121 _n located at the end of the row is increased, referring to FIG. The film thickness in the range facing the targets 124 ₁ , 125 _n increases, but the film thickness in the range facing the other targets 125 ₁ , 124 _n also increases, resulting in a portion thicker than the central region. There was a problem that.

JP 2005-290550 A

  The present invention was created in order to solve the above-described disadvantages of the prior art, and an object of the present invention is to provide a sputtering apparatus and a sputtering method capable of forming a thin film having a uniform film thickness on the edge of a substrate.

In order to solve the above-described problems, the present invention provides a vacuum chamber, a plurality of elongated cathode electrodes disposed in the vacuum chamber, and an elongated shape, and the longitudinal direction of each cathode electrode is on each cathode electrode. The cathode electrodes are parallel to each other in the longitudinal direction, and the surfaces of the targets on the cathode electrodes to be sputtered are located on the same plane, and the targets When the two adjacent targets among the targets are set as one set of targets, an on-voltage at which sputtering is performed and an off-voltage at which sputtering is stopped are arranged. A power supply device that alternately applies to the two targets in the set of targets via the cathode electrode is provided. In the target group, a sputtering apparatus that applies the off-voltage to at least one target, the target group being arranged in a line, and the target group positioned at the end of the line by the power supply device. In the sputtering apparatus, the on-voltage application period of the target positioned toward the end of the row is longer than the on-voltage application period of the other target.
The present invention is a sputtering apparatus, wherein the cycle of the on-voltage and the off-voltage of the target set is the same length, and the application period of the on-voltage of the target located at the end of the row is other than In the sputtering apparatus, the target is turned on longer than the application period of the on-voltage.
The present invention is a sputtering apparatus, wherein the on-voltage application period is the same in the target group between the target groups at both ends of the row.
The present invention is a sputtering apparatus, wherein the vacuum chamber is connected to a ground potential, the on voltage is a negative voltage, and the off voltage is a positive voltage or a ground potential.
This invention is a sputtering device, Comprising: It has a substrate holder with which a substrate which faces the target located inside the both ends of the line among the targets is arranged, and the target located at the edge of the line is , At least a part of the sputtering apparatus positioned outside the range facing the substrate.
In the present invention, two adjacent targets among a plurality of elongated targets arranged in a vacuum chamber so that the longitudinal directions are parallel to each other, the surfaces to be sputtered are located on the same plane, and the side surfaces face each other are arranged. When the target is set as one target set, an on-voltage at which sputtering is performed and an off-voltage at which sputtering is stopped are alternately applied to the two targets in the set of targets. A sputtering method for sputtering and forming a thin film on a substrate disposed in the vacuum chamber, wherein the target set is arranged in a line, and when applying the on voltage and the off voltage to the target In the target set located at the end of the row, the application period of the on-voltage of the target located toward the end of the row is set in front of the other. A sputtering method to be longer than the application period of the ON voltage of the target.
The present invention is a sputtering method, and when applying the on-voltage and the off-voltage to the target, the cycle of the on-voltage and the off-voltage of the target set is set to the same length, and the one row In the sputtering method, the on-voltage application period of the target located at the end is longer than the on-voltage application period of the other target.
The present invention is a sputtering method, wherein when the on-voltage and the off-voltage are applied to the target, the on-voltage application period is set in the target group between the target groups at both ends of the row. This is the same sputtering method.
The present invention is a sputtering method, wherein the vacuum chamber is connected to a ground potential, and when the on voltage and the off voltage are applied to the target, the on voltage is a negative voltage, and the off voltage is This is a sputtering method for setting a positive voltage or a ground potential.
The present invention is a sputtering method, and before applying the on-voltage and the off-voltage to the target, the substrate is opposed to the target located on the inner side of both ends of the row, and the substrate is placed at the end of the row. In this sputtering method, at least a part of the target positioned is positioned outside a range facing the substrate.

  Since a thin film having a uniform thickness can be formed at the edge of the substrate, the productivity of a large substrate is improved.

Internal configuration diagram of sputtering apparatus of the present invention Plan view of target and cathode electrode Schematic diagram for explaining the structure of the magnet device Timing chart of voltage applied to target group between target groups at both ends of one row Timing chart of voltage applied to target set located at the end of one row The schematic diagram for demonstrating the film thickness distribution of the thin film by this invention A graph showing the relationship between the measurement position along the longitudinal direction of the target and the sheet resistance standard value Internal configuration diagram of conventional sputtering equipment Schematic diagram for explaining the film thickness distribution of a thin film according to the prior art Schematic diagram for explaining the film thickness distribution of the thin film when the voltage value of the target group located at the end of one row is increased

<Structure of sputtering apparatus>
The structure of the sputtering apparatus of the present invention will be described.
FIG. 1 is an internal configuration diagram of the sputtering apparatus 10.

The sputtering apparatus 10 has an elongated shape with a vacuum chamber 11 and a plurality of elongated cathode electrodes 22 ₁ , 23 _{1 to} 22 _n , 23 _n disposed in the vacuum chamber 11, and each cathode electrode 22 ₁ , 23 _1. .., 22 _n , 23 _n have targets 24 ₁ , 25 ₁ -24 _n , 25 _n whose longitudinal direction is arranged along the longitudinal direction of each cathode electrode 22 ₁ , 23 ₁ -22 _n , 23 _n. is doing.

FIG. 2 is a plan view of the targets 24 ₁ , 25 _{1 to} 24 _n and 25 _n and the cathode electrodes 22 ₁ , 23 _{1 to} 22 _n and 23 _n .
Here, the targets 24 ₁ , 25 _{1 to} 24 _n , 25 _n have the same shape and the same size. The targets 24 ₁ , 25 _{1 to} 24 _n and 25 _n may be conductive materials or insulating materials.

The cathode electrodes 22 _1, 23 ₁ through 22 _n, 23 _n, the longitudinal directions parallel to each other, the target 24 _1, 25 ₁ to 24 _n, 25 of the cathode electrodes 22 _1, 23 ₁ on through 22 _n, 23 _{n The n} sputtered surfaces are located on the same plane, and the adjacent targets 24 ₁ , 25 _{1 to} 24 _n , 25 _n are arranged side by side so as to face each other.

Here, one end in the longitudinal direction of each target 24 ₁ , 25 _{1 to} 24 _n , 25 _n is located on one straight line perpendicular to the longitudinal direction, and the other end is another one perpendicular to the longitudinal direction. It is aligned so that it lies on a straight line.
The side surfaces of the adjacent targets 24 ₁ , 25 _{1 to} 24 _n , 25 _n are spaced at the same interval.
Of the targets 24 ₁ , 25 _{1 to} 24 _n , 25 _n , when two adjacent targets are set as one set of target sets, the target sets are arranged in a line. Reference numerals 21 _{1 to} 21 _{n denote} target sets.

Referring to FIG. 1, sputtering apparatus 10 includes an on-voltage at which sputtering is performed and an off-voltage at which sputtering is stopped via a set of targets via cathode electrodes 22 ₁ , 23 _{1 to} 22 _n and 23 _n. A power supply device 30 for alternately applying to two targets in the set is provided.

In this embodiment, the power supply device 30 has a plurality of auxiliary power supplies 31 _{1 to} 31 _n . Each auxiliary power supply 31 _{1 to} 31 _n is electrically connected to two cathode electrodes on which two targets of different target groups 21 _{1 to} 21 _n are arranged.

  The power supply device 30 applies an off voltage to at least one target in one set of targets. That is, in one set of targets, an off voltage is applied to the other target while an on voltage is applied to one target.

Here, the vacuum chamber 11 is connected to the ground potential, the on-voltage is a negative voltage, and the off-voltage is a positive voltage. For this reason, when plasma is generated in the vacuum chamber 11, cations in the plasma are incident on a target to which an on-voltage is applied and are sputtered.
Although the off voltage is a positive voltage here, the off voltage may be a ground potential, or may be changed from the ground potential to the positive voltage or from the positive voltage to the ground potential during the off voltage application period.

FIG. 4 is a timing chart of voltages applied to the target groups 21 _{2 to} 21 _n−1 between the target groups at both ends of the row, and reference numeral 51 denotes one of two targets in one target group. The reference numeral 52 indicates the time change of the voltage applied to the other.

Here, in the target sets 21 _{2 to} 21 _n−1 between the target sets at both ends of the row, the on-voltage application period T ₁ of one target in one set of target sets is equal to the on-voltage of the other target. is the same as the application period T _2. In addition, in two targets in one set of targets, the magnitude of the on-voltage and the magnitude of the off-voltage are the same. Therefore, the sputter amounts of the two targets in one set of targets are the same.

Further, the ON voltage application periods T ₁ and T ₂ are made the same through the target groups 21 _{2 to} 21 _n-1 between the target groups at both ends of the row, and the magnitudes of the on voltage and the off voltage are respectively set. It is made the same through target sets 21 _{2 to} 21 _n-1 between the target sets at both ends of the row.

Therefore, in the target groups 21 _{2 to} 21 _n-1 between the target groups at both ends of the one row, the sputtering amount of each target is the same, and when the substrate 41 is held by a substrate holder 42 described later, Among them, in the range facing the target groups 21 _{2 to} 21 _n-1 between the target groups at both ends of the row (hereinafter referred to as the central region), the same amount of particles reach per unit area, and the thin film has a uniform film thickness. Is to be formed.

FIG. 5 is a timing chart of voltages applied to the target groups 21 ₁ and 21 _n positioned at the ends of the one row, and reference numeral 53 denotes a position of the two targets in the target group toward the end of the one row. The time change of the voltage applied to the target 24 ₁ , 25 _n is shown, and the reference numeral 54 shows the time change of the voltage applied to the other 25 ₁ , 24 _n .

In the target set 21 ₁ , 21 _n positioned at the end of the row by the power supply device 30, the on-voltage application period T _{3 of} the targets 24 ₁ , 25 _n positioned toward the end of the row is the other target. The on-voltage application period T ₄ is set longer than 25 ₁ and 24 _n . In addition, the two targets in one set of targets have the same on-voltage magnitude and the same off-voltage magnitude. Therefore, as will be described later, the sputtering amount of the targets 24 ₁ , 25 _n located toward the end of the one row is larger than the sputtering amount of the other targets 25 ₁ , 24 _n .

Further, the on-voltage and off-voltage periods of the respective target groups 21 _{1 to} 21 _n have the same length, and the on-voltage application period T ₃ of the targets 24 ₁ and 25 _n located at the ends of the one row is other than The on-voltage application periods T ₁ , T ₂ , and T ₄ of the targets 25 _{1 to} 24 _n are made longer. Therefore, if the magnitude of the on-voltage and the magnitude of the off-voltage are the same throughout each of the target groups 21 _{1 to} 21 _n , the sputtering amount of the targets 24 ₁ and 25 _n positioned at the end of the one row is the other target 25 _1. More than ~ 24 _n spatter.

Referring to FIG. 1, the sputtering apparatus 10 includes a substrate holder 42 on which a substrate 41 facing the targets 25 _{1 to} 24 _n positioned inside the one row of the targets is disposed.
The targets 24 ₁ and 25 _n positioned at the ends of the row are positioned outside a range in which at least a part faces the substrate 41. That is, the surface of the substrate 41 are contained inside the range that faces the target 24 ₁ to 25 _n, so as not to protrude outside the range that faces the target 24 ₁ to 25 _n.

<Sputtering method>
A film forming method using the above-described sputtering apparatus 10 will be described.
Within the target group 21 ₁ , 21 _n located at the end of the one row, the on-voltage application period T _{3 of} the targets 24 ₁ , 25 _n located toward the end of the one row and the other targets 25 ₁ , 24 _n The ratio between the on-voltage application period T ₄ and the thickness of the thin film formed on the surface of the substrate 41 in the range facing the targets 24 ₁ , 25 _n positioned toward the end of the row and the other target 25 ₁ and 24 _n and the on-voltage application period T ₃ of the target located at the end of the row is more than the other on-voltage application period T ₄ so that the film thickness in the facing range is the same. In advance, the value becomes longer by simulation or testing.

The sputtering apparatus 10 includes an evacuation apparatus 12 that evacuates the vacuum chamber 11 and a gas supply unit 13 that supplies a sputtering gas into the vacuum chamber 11.
The vacuum chamber 11 is evacuated by the evacuation device 12 to form a vacuum atmosphere. Thereafter, evacuation by the evacuation device 12 is continued, and the vacuum atmosphere in the vacuum chamber 11 is maintained.

While maintaining the vacuum atmosphere in the vacuum chamber 11, the substrate 41 is carried into the vacuum chamber 11 while being held by the substrate holder 42, and the targets 251 to 24 located inside the one row of the targets among the targets 25 _{1 to} 24. Stop at the position facing the sputtered surface of _n . The targets 24 ₁ , 25 _n positioned at the ends of the row are positioned outside a range where at least a part thereof faces the substrate 41.
A sputtering gas is introduced into the vacuum chamber 11 from the gas introduction part. Here, Ar gas is used as the sputtering gas.

An ON voltage and an OFF voltage are alternately applied from the power supply device 30 to the targets 24 ₁ , 25 _{1 to} 24 _n and 25 _n via the cathode electrodes 22 ₁ , 23 _{1 to} 22 _n and 23 _n . Within one set of targets, an off voltage is applied to at least one target.
The cycle of the ON voltage and the OFF voltage of each target set 21 _{1 to} 21 _{n is} the same, and here, the cycle is 0.1 kHz to 5 kHz.

Further, at least the target sets 21 _{2 to} 21 _n-1 inside the both ends of the one row have the same on-voltage and the same off-voltage.
When voltages having opposite polarities are applied to two adjacent targets in one set of targets, a discharge is generated between the surfaces of the two targets, and the introduced sputtering gas is turned into plasma.

Cathode electrode _{22 1, 23 1 ~22 n,} 23 target 24 ₁ of _n, 25 ₁ to 24 _n, 25 magnet apparatus 26 ₁ on the back side opposite to the _n placement surface, 27 ₁ ~ 26 _n 27 _n are arranged.
The magnet devices 26 ₁ , 27 _{1 to} 26 _n and 27 _n have the same structure, and will be described by using a magnet device _denoted by reference numeral 26 ₁ .

Figure 3 is a schematic view for explaining the structure of the magnet device 26 _1.
Magnet device 26 ₁ and a second magnet 26b that are arranged with the first magnet 26a which is annularly inside the ring of the first magnet 26a. Each of the first and second magnets 26a and 26b has magnetic poles at both ends in the thickness direction.

First and second magnets 26a, 26b is directed opposite polarity magnetic pole of the rear surface of the cathode electrode 22 ₁ to each other, and the cathode electrode 22 ₁ on the surface of the opposite side in close contact with magnet plate 26c is fixed Has been.
Here, it is facing the N pole and the rear surface S pole of the cathode electrode 22 ₁ of the second magnet 26b of the first magnet 26a is, S and N poles of the second magnet 26b of the first magnet 26a May face the back surface of the cathode electrode 22 ₁ .

Magnetic field lines passing through the surface of the target 24 ₁ are formed between the first and second magnets 26a and 26b, and ions in the plasma are captured by the magnetic field lines.
When an on-voltage is applied to the target 24 ₁ , ions in the plasma are incident on the surface of the target 24 ₁ while being captured by the magnetic lines of force, and the target 24 ₁ is sputtered.

Magnet moving device 29 is provided in the magnet device 26 _1. The magnet moving device 29 is a motor, and is configured to transmit power to the magnet device 26 ₁ so that the magnet device 26 ₁ can move in a plane parallel to the surface of the target 24 ₁ .

Although sputtering amount increases lower part is the portion having a high magnetic flux density of the target 24 _first surface, by moving the magnet device 26 ₁ by the magnet moving unit 29 moves the portion of high magnetic flux density at the target 24 ₁ inner surface If, in the target 24 ₁ in the surface without causing a difference in amount of spatter, the target 24 ₁ surface is uniformly sputtered.
Referring to FIG. 1, the sputtered targets 24 ₁ , 25 _{1 to} 24 _n , 25 _n particles reach and adhere to the surface of the substrate 41 and a thin film is formed on the surface of the substrate 41.

Referring to FIG. 4, in the target sets 21 _{2 to} 21 _n−1 between the target sets at both ends of the row, the on-voltage application period T ₁ of one target in one target set is set to the other target. The on-voltage application period T ₂ is set to be the same. Then, the sputter amounts of two adjacent targets in one target set are the same.

Further, the ON voltage application period is made the same through the target sets 21 _{2 to} 21 _n-1 between the target sets at both ends of the row. Then, the sputtering amount of each target of the target groups 21 _{2 to} 21 _n-1 between the target groups at both ends of the one row becomes the same.

The surface of the substrate 41 faces the targets 25 _{1 to} 24 _n positioned on the inner side of both ends of the row of targets, and the same amount of particles per unit area reaches the central region of the surface of the substrate 41. A thin film having a uniform thickness is formed in the central region.

Referring to FIG. 5, in the target set 21 ₁ , 21 _n positioned at the end of the row, the on-voltage application period T ₃ of the targets 24 ₁ , 25 _n positioned at the end of the row is The target 25 ₁ , 24 _{n has} a predetermined length longer than the ON voltage application period T ₄ .

Then, the sputtering amount of the targets 24 ₁ and 25 _n positioned at the end of the row increases more than before, and the sputtering amount of the targets 25 ₁ and 24 _{n that} are one inner side from the end of the row decreases than before. Due to the effect of the superposition of the particles emitted from each of the targets 24 _{1 to} 25 _n , the particle arrival amount in the range facing the targets 24 ₁ and 25 _n located at the end of the one row on the surface of the substrate 41 and the end of the one row The amount of particles that reach the inner targets 25 ₁ and 24 _n that face each other is the same, and a thin film having a uniform thickness is formed in the end region.

The on-voltage and off-voltage periods of the target sets 21 _{1 to} 21 _n have the same length, and the on-voltage application period T ₃ of the targets 24 ₁ and 25 _n located at the ends of the one row is the other target 25. application period T ₁ of the ₁ to 24 _n of the on-voltage, T _2, T longer than _4, application period T ₄ of the target 25 _1, 24 _n of oN voltage of one inside the end of the one row other targets 24 ₁ , 24 _{2 to} 25 _n−1 , and 25 _n ON voltage application periods T ₁ , T ₂ , and T ₃ are shorter.

It is able to each thin film having a uniform thickness is formed on the central region and the end region, and distance between the target 24 ₁ to 25 _n surface and the substrate 41 surface, the target 24 ₁ to 25 _n and the substrate 41 Depending on conditions such as shape and size, there may be a difference between the thickness of the thin film in the end region and the thickness of the thin film in the central region.

When the thickness of the thin film in the end region is smaller than the thickness of the thin film in the central region, the magnitude of the voltage applied to the target sets 21 ₁ and 21 _n positioned at the end of the row is increased. Then, the sputtering amount of the target sets 21 ₁ and 21 _n positioned at the end of the row increases, the film thickness of the end region increases, and the difference in film thickness between the end region and the central region is reduced. .
Alternatively, the voltage applied to the target sets 21 _{2 to} 21 _n-1 inside the both ends of the row is reduced to reduce the thickness of the central region, and the thickness of the end region and the central region. The difference may be reduced.

When the thickness of the thin film in the end region is larger than the thickness of the thin film in the central region, the magnitude of the voltage applied to the target sets 21 ₁ and 21 _n located at the end of the row is reduced. Then, the sputtering amount of the target sets 21 ₁ and 21 _n positioned at the end of the row is reduced, the film thickness of the end region is reduced, and the difference in film thickness between the end region and the central region is reduced. .
Alternatively, the thickness of the central region is increased by increasing the magnitude of the voltage applied to the target sets 21 _{2 to} 21 _n-1 inside the both ends of the row, and the film thickness of the end region and the central region. The difference may be reduced.
In this way, thin films having the same film thickness are formed in the end region and the central region of the surface of the substrate 41.

Cu (copper) targets 24 ₁ and 25 ₁ having a longitudinal length of 2200 mm were arranged on the cathode electrodes 22 ₁ and 23 ₁ of the target set 21 ₁ located at one end of the row, respectively.
The cycle of the on-voltage and off-voltage of the power supply device 30 is set to 1 kHz, the on-voltage application period T ₃ of the target 24 ₁ located toward the end of the one row is 0.5 msec, and the on-voltage of the other target 25 ₁ the application period T ₄ of the set to 0.5msec. When the application period T ₃ of the target 24 ₁ ON voltage located towards the end of the one row with respect to one period is referred to as a duty ratio, the duty ratio is 50%.

After evacuating the inside of the vacuum chamber 11 to form a vacuum atmosphere, the substrate 41 is carried into the vacuum chamber 11 and is stopped at a position facing the targets 25 _{1 to} 24 _n positioned inside both ends of the one row. . At this time, at least a part of the targets 24 ₁ , 25 _n located at the ends of the one row are located outside the range facing the substrate 41.

Ar gas is introduced into the vacuum chamber 11, and sputtering is performed by alternately applying an on voltage and an off voltage only to the two targets 24 ₁ and 25 _{1 of} the target set 21 ₁ located at the one end from the power supply device 30. Then, a Cu thin film was formed on the surface of the substrate 41.
After the thin film is formed, the voltage application to the targets 24 ₁ and 25 ₁ is stopped, the introduction of Ar gas into the vacuum chamber 11 is stopped, and the substrate 41 is held in the vacuum chamber while maintaining the vacuum atmosphere in the vacuum chamber 11. 11 to the outside.

Next, the sheet resistance in the range facing the target 24 ₁ closer to the end in the target set 21 ₁ located at the one end of the surface of the substrate 41 and the sheet resistance in the range facing the other target 25 _1. Was measured at a plurality of measurement positions along the longitudinal direction of the targets 24 ₁ and 25 ₁ .
The measured sheet resistance was divided by 1.2Ω / □ to obtain a sheet resistance standard value [%]. The measurement results are shown in FIG. The thin film is a Cu film, and the sheet resistance standard value is inversely proportional to the film thickness of the thin film.

Next, of the two targets of the target set 21 ₁ positioned at the one end, the on-voltage application period T ₃ of the target 24 ₁ positioned toward the end of the row is 0.6 msec, and the other target 25 ₁ the application period T ₄ of the on-voltage was changed to 0.4 msec (the duty ratio is 60%), was repeated the measurement step and the above-described film formation step. The measurement results are shown in FIG.

Further, among the two targets of the target set 21 ₁ positioned at the one end, the ON voltage application period T ₃ of the target 24 ₁ positioned toward the end of the row is 0.7 msec, and the other target 25 ₁ the application period T ₄ of the on-voltage was changed to 0.3 msec (the duty ratio is 70%), was repeated the measurement step and the above-described film formation step. The measurement results are shown in FIG.

When the measurement result of FIG. 7 is seen, as the duty ratio is increased, that is, the on-voltage application period T ₃ of the target 24 ₁ located toward the end of the one row is lengthened, and the on-voltage of the other target 25 ₁ is increased. The shorter the application period T ₄ , the smaller the sheet resistance standard value in the range facing the target 24 ₁ located toward the end of the row (that is, the thicker the film thickness), and the other target 25 ₁ facing. It can be seen that the sheet resistance standard value within the range can be increased (that is, the thickness of the thin film can be reduced).

In FIG. 7, when the duty ratio is 50%, the difference between the sheet resistance standard values in the range facing the two targets of the target group 21 ₁ located at the one end is the smallest, but the target group 21 located at the one end is the smallest. _When not only ₁ but also other target sets 21 _{2 to} 21 _n are sputtered together, the film thickness increases as the distance from the end increases due to the effect of superposition of particles emitted from each target, and the duty ratio is 50%. the difference between the target set 21 ₁ of sheet resistance standard value of the two targets and ranges facing each located at one end is spread, whereas the duty ratio is shortened is the difference in the 60% or 70%.

10 ...... sputtering apparatus 11 ...... vacuum chamber 21 ₁ through 21 _n ...... target pairs _{22 1, 23 1 ~22 n,} 23 n ...... cathode electrodes _{24 1, 25 1 ~24 n,} 25 n ...... targets 30 ... ... Power supply 41 ... Substrate 42 ... Substrate holder

Claims (10)

A vacuum chamber;
A plurality of elongated cathode electrodes disposed in the vacuum chamber;
An elongated shape, and on each of the cathode electrodes, the target has a longitudinal direction arranged along the longitudinal direction of each of the cathode electrodes,
Each of the cathode electrodes is arranged in parallel such that the longitudinal directions thereof are parallel to each other, the surfaces of the targets on the cathode electrodes to be sputtered are located on the same plane, and the side surfaces of the targets face each other.
When the two adjacent targets among the targets are set as a set of targets, an on-voltage at which sputtering is performed and an off-voltage at which sputtering is stopped are set via the cathode electrode. A power supply device that alternately applies to the two targets in the set is provided,
The power supply device is a sputtering device that applies the off-voltage to at least one of the targets in a set of the targets,
The target groups are arranged in a line, and within the target group located at the end of the line by the power supply device, the on-voltage application period of the target located toward the end of the line is the other Sputtering apparatus which is made longer than the application period of the on-voltage of the target.   Periods of the on-voltage and the off-voltage of the target set are set to the same length, and an on-voltage application period of the target located at the end of the row is an on-voltage application period of another target. The sputtering apparatus according to claim 1, wherein the sputtering apparatus is made longer.   3. The sputtering apparatus according to claim 1, wherein the application period of the ON voltage is the same in the target group between the target groups at both ends of the row.   The sputtering apparatus according to claim 1, wherein the vacuum chamber is connected to a ground potential, the on-voltage is a negative voltage, and the off-voltage is a positive voltage or a ground potential. Among the targets, a substrate holder on which a substrate facing the target located on the inner side than both ends of the row is arranged,
5. The sputtering apparatus according to claim 1, wherein at least a part of the targets positioned at the end of the line is positioned outside a range where the target faces the substrate. 6. Two adjacent targets among a plurality of elongated targets arranged in a vacuum chamber in which the longitudinal directions are parallel to each other, the surfaces to be sputtered are located in the same plane, and the side surfaces face each other are arranged. If you make one target set,
A substrate disposed in the vacuum chamber by alternately applying an on-voltage at which sputtering is performed and an off-voltage at which sputtering is stopped to the two targets in the set of targets to sputter the target. A sputtering method for forming a thin film on
The target group is arranged in a line, and when applying the on voltage and the off voltage to the target, the target group is positioned toward the end of the line in the target group located at the end of the line. The sputtering method of making the on-voltage application period of the target to be longer than the on-voltage application period of the other target.   When applying the on-voltage and the off-voltage to the target, the on-voltage and the off-voltage of the target set have the same length as each other, and the on-state of the target positioned at the end of the row is set. The sputtering method according to claim 6, wherein a voltage application period is made longer than an application period of the on-voltage of the other target.   The application period of the on-voltage is set to be the same in the target set between the target sets at both ends of the row when the on-voltage and the off-voltage are applied to the target. 8. The sputtering method according to any one of 7 above.   The vacuum chamber is connected to a ground potential, and when the on voltage and the off voltage are applied to the target, the on voltage is a negative voltage, and the off voltage is a positive voltage or a ground potential. The sputtering method according to any one of claims 6 to 8.   Before applying the on-voltage and the off-voltage to the target, the substrate faces the target located on the inner side of both ends of the row, and at least a part of the target located at the end of the row is 10. The sputtering method according to claim 6, wherein the sputtering method is positioned outside a range facing the substrate. 11.

Images