JP2011089146A - Sputtering apparatus and sputtering method - Google Patents

Abstract

In a small magnetron sputtering cathode, the film thickness and film quality uniformity in a substrate surface of a thin film formed on a large substrate are improved.
With an axis passing through the center of rotation 9 of a substrate holder 7 as a reference, the film is made of the same kind of film-forming material at a distance L ₁ and a distance L ₂ (> L ₁ ) in the outer circumferential direction. Are equal to each other, and a plurality of targets 1a and 1b that are smaller than the area of the substrate holder 7 and are electrically insulated through the insulating material 108 are arranged in the longitudinal direction of the targets 1a and 1b. The sputtering cathode 103 is provided in parallel with the radial direction.
[Selection] Figure 1

Description

  The present invention relates to a sputtering apparatus and a sputtering method for improving uniformity of film thickness and film quality within a substrate surface of a thin film formed on a large substrate with a small magnetron sputtering cathode.

  Sputtering has better controllability of film thickness than vacuum evaporation, and it is a thin film forming technology that can form thin films of high melting point materials and compounds relatively easily. Widely used in industrial fields such as parts. In particular, the magnetron sputtering method using a permanent magnet or an electromagnet as a magnetic circuit solves the problem of the sputtering method in which the formation rate of the thin film is about 1 to 2 digits slower than the vacuum evaporation method, and enables mass production by the sputtering method. ing.

  Hereinafter, a conventional general magnetron sputtering cathode, a sputtering apparatus equipped with the cathode, and a sputtering method will be described with reference to FIGS.

  9 is a schematic plan view of a magnetron sputtering cathode having a conventional flat plate target, FIG. 10 is a schematic cross-sectional view taken along the line AA of FIG. 9, and FIG. 11 is a perspective view of the magnetron sputtering cathode.

  9 and 10, reference numeral 1 denotes a flat target, which is adhered to the backing plate 2 with a soldering agent such as indium and is installed on the cathode body 3. On the back side of the target 1, a magnetic circuit 4 for magnetron discharge is disposed so as to form a closed magnetic force line 5 and at least a part of the magnetic force line 5 is parallel to the surface of the target 1.

  For this reason, a toroidal closed tunnel-like magnetic field 6 (shaded portion in the figure) is formed on the surface of the target 1 as shown in FIG.

  Next, the principle of operation of the magnetron sputtering cathode configured as described above and the magnetron sputtering apparatus equipped with the cathode will be described.

  FIG. 12 is a schematic view of a sputtering apparatus provided with the magnetron sputtering cathode.

In FIG. 12, the sputtering cathode 103 is usually installed in the vacuum chamber 107 via an insulating material 108. In order to form a thin film by magnetron sputtering, the vacuum chamber 107 is evacuated to a high vacuum (about 10 ⁻⁴ to 10 ⁻⁵ Pa) by a vacuum exhaust system such as a vacuum pump 109, and a discharge gas such as Ar is used as a gas. The gas is introduced into the vacuum chamber 107 through the gas flow regulator 110 of the introduction system, and the pressure regulating valve 111 is adjusted to keep the pressure in the vacuum chamber at about 10 ⁻¹ to 10 ⁻² Pa.

  Here, by applying a negative voltage from a DC or AC sputtering power source 112 connected to the sputtering cathode 103 to which the target 1 is attached, a magnetron discharge occurs around the electric field and the toroidal tunnel magnetic field generated by the magnetic circuit, The target 1 is sputtered and the sputtered particles are deposited on the substrate 8 placed on the substrate holder 7 to form a thin film on the substrate 8.

  Here, in the sputtering apparatus in which the positional relationship between the target 1 and the substrate 8 is a stationary facing type as described above, a target having a larger area is required to ensure film thickness uniformity within the substrate surface. This is because, in the magnetron sputtering method, the plasma density increases at the strongest part of the magnetic force lines passing in parallel with the target surface, so that the erosion region to be sputtered and the sputtered particles are reattached (not sputtered) on the target. This is because the erosion of the target proceeds non-uniformly due to the formation of the region, and in reality, a sputtering cathode having a target having a larger area than the substrate on which the thin film is formed is used, and the configuration of the magnetic circuit and the target and substrate It is necessary to sufficiently adjust the distance between them (hereinafter referred to as T / S distance).

  Specifically, for example, if it is intended to achieve a film thickness uniformity within the substrate surface of about ± 1%, one side of the target is about twice as large as one side of the substrate, that is, relative to the area of the substrate. A target having about four times the area is required.

  FIG. 13 and FIG. 14 show the configuration of the target and the substrate that represent the relationship of the sizes of the aforementioned parts. 13 is a schematic plan view showing the relationship between the target and the size of the substrate necessary for ensuring uniformity, and FIG. 14 is a schematic cross-sectional view taken along the line AA of FIG.

  In the examples shown in FIGS. 13 and 14, for example, if the size of the substrate 8 is 300 mm in diameter, the diameter of the target 1 is required to be 600 mm.

  Currently, the size of the substrate is increasing to increase the number of products, mainly semiconductors and displays, and in order to cope with this, the size of the target is inevitably increased. As a result, the equipment cost and equipment occupation area due to the increase in the size of the sputtering equipment itself, the cost required for maintenance (regeneration of jigs such as the protective plate and earth shield), and the increase in time have become problems. ing.

  Furthermore, the increase in the size of the target causes problems that the target itself is expensive, and that the target itself cannot be manufactured with a rare metal or a multi-element (or alloy) target having a complicated composition. In addition, poor material utilization efficiency due to local erosion of a part of the target, which is a feature of magnetron sputtering, is also a problem.

  On the other hand, along with the increase in size of substrates, new issues are step coverage (step or bottom coverage) on line and space and via holes formed on substrates such as semiconductors and electronic components, or lenses that are optical components Uniform film formation on a three-dimensional object such as

  The requirement for thin film formation in these three-dimensional shapes is not only the improvement of the absolute value of the film thickness at the stepped part and the inclined part, but also the installation place of three-dimensional objects such as lenses installed on the substrate surface or on the substrate holder. This is an improvement in uniformity.

  That is, as described above, even if the film thickness uniformity on the substrate plane can be improved by enlarging the target area in response to the enlargement of the substrate, it is necessary to form the substrate for local erosion formation of the target. Asymmetry of the coverage with respect to the step (inclined portion) due to the difference in the incident angle of the sputtered particles at the position, particularly at the center and the outer periphery, occurs, resulting in variations in device performance and a decrease in yield.

  In order to solve these problems, a wide range of efforts have been made to enable uniform thin film formation on a large substrate using a small sputtering cathode.

  Hereinafter, these conventional approaches will be described with reference to FIGS. 15 to 17, the same components as those in FIGS. 9 to 14 are denoted by the same reference numerals and description thereof is omitted. The operation method is also substantially the same as that of the conventional general magnetron sputtering apparatus shown in FIG.

  FIG. 15 is a schematic plan view showing the positional relationship between a target and a substrate of a magnetron sputtering apparatus having a film thickness correction plate, and FIG. 16 is a schematic cross-sectional view taken along line AA of FIG.

  A feature of sputtering film formation by the sputtering apparatus in this system is that the space between the substrate 8 placed on the substrate holder 7 that rotates about the rotation center 9 of the substrate holder 7 and the small sputtering cathode 103 that is opposed to the substrate holder 7 is A shield plate 11 provided with slits 10 through which sputtered particles 12 pass is installed, and by optimizing the shape of the slits 10, the sputtered particles 12 reaching the substrate 8 are controlled to improve the film thickness uniformity. Yes (see, for example, Patent Document 1).

  FIG. 17 is a schematic perspective view showing a positional relationship between a target and a substrate of a sputtering apparatus equipped with an inclined sputtering cathode.

  A characteristic of sputtering film formation by a sputtering apparatus in this system is that a substrate 8 is rotated around a rotation center 9 of a substrate holder 7 and a small sputtering cathode 103 having a target 1 having an area smaller than that of the substrate 8 is provided. The film thickness is improved by inclining it at a position that satisfies the conditions (for example, see Patent Document 2).

  All of these methods are known to have a certain effect in improving the film thickness uniformity on the substrate plane.

JP-A-9-213634 JP 2009-1912 A

  However, in the conventional configuration shown in FIGS. 15 and 16, the uniformity is improved by removing a part of the sputtered particles 12 protruding from the target 1 with the shield plate 11 (film thickness correction plate). This leads to a decrease in film speed and a decrease in material utilization efficiency. In addition, since film deposition on the shield plate 11 increases with time, there is a concern about the generation of dust due to the peeling of the deposited film as well as the film thickness variation due to the time-dependent change of the slit 10. For this reason, it is predicted that the equipment operation rate will decrease due to an increase in the number of times of apparatus maintenance, and there is a problem in terms of efficient productivity.

  In addition, since the conventional configuration shown in FIG. 17 limits the positional relationship such as the tilt angle between the substrate 8 and the sputtering cathode 103 to some extent, there is a concern that there is a limit in improving the film thickness uniformity. It seems that there is a problem for a device such as an optical filter that requires highly accurate film thickness uniformity (for example, film thickness uniformity of ± 0.3% or less). In addition, since the incident angle of the sputtered particles 12 is limited to some extent, asymmetry occurs in the film thickness of the step (inclined part) to the three-dimensional shape in the substrate surface, resulting in variations in device performance. It has the problem of leading to a decrease in yield.

  The present invention solves the above-described conventional problems, and a sputtering apparatus and sputtering capable of improving the film thickness and film quality uniformity in a substrate surface of a thin film formed on a large substrate with a small magnetron sputtering cathode. It aims to provide a method.

  In order to achieve the above object, a sputtering apparatus and a sputtering method of the present invention include a vacuum chamber having an exhaust system and a gas introduction system, a sputtering cathode installed in the vacuum chamber and having a target, and a substrate. A sputtering apparatus comprising a rotatable substrate holder and a sputtering power source connected to the sputtering cathode, wherein the sputtering cathode is made of a same kind of film forming material and has a plurality smaller than the area of the substrate holder. A thin film is formed on the substrate placed on the substrate holder by using a sputtering apparatus in which the target is electrically insulated, using a magnetron discharge for the plurality of targets provided on the sputtering cathode, and rotating the substrate holder Characterized by forming That.

  With this configuration, the amount and direction of sputtered particles reaching the large substrate can be controlled and uniformized in the plane.

  According to the sputtering apparatus and the sputtering method of the present invention, it is possible to improve the film thickness and film quality uniformity in the substrate surface of the thin film formed on the large substrate with the small magnetron sputtering cathode.

Schematic plan view showing the positional relationship between the target and substrate of the sputtering apparatus and the connection state of the sputtering power supply in Embodiment 1 of the present invention AA cross-sectional schematic diagram of the first embodiment of FIG. Schematic plan view showing the positional relationship between the target and the substrate of the sputtering apparatus in Embodiment 2 of the present invention Schematic plan view showing the positional relationship between the target and substrate of the sputtering apparatus and the connection state of the sputtering power supply in Embodiment 3 of the present invention AA cross-sectional schematic diagram of the third embodiment of FIG. Schematic plan view showing the positional relationship between another target and the substrate of the sputtering apparatus in Embodiment 3 of the present invention Schematic plan view showing the connection state of another sputtering power supply in Embodiment 3 of the present invention Schematic plan view showing the positional relationship between the target and the substrate of the sputtering apparatus according to Embodiment 4 of the present invention. A schematic plan view of a conventional magnetron sputtering cathode AA cross-sectional schematic diagram of the conventional example of FIG. Schematic perspective view of a conventional magnetron sputtering cathode Schematic diagram of a typical sputtering system equipped with a conventional magnetron sputtering cathode Schematic plan view showing the relationship between the target and substrate size required to ensure film thickness uniformity in the conventional example AA cross-sectional schematic diagram of the conventional example of FIG. Schematic plan view showing the positional relationship between the target and substrate of a magnetron sputtering apparatus having a conventional film thickness correction plate AA cross-sectional schematic diagram of the conventional example of FIG. Schematic perspective view showing the positional relationship between a target and a substrate of a sputtering apparatus equipped with a conventional inclined sputtering cathode

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic plan view showing a positional relationship between a target and a substrate of a sputtering apparatus according to Embodiment 1 of the present invention, and a state in which a sputtering power source is connected to the target, and FIG. 2 is a schematic cross-sectional view taken along line AA in FIG. is there. In the following description, the same components as those in FIGS. 9 to 17 are denoted by the same reference numerals and description thereof is omitted.

  The basic configuration and operation of the present embodiment described below are substantially the same as those of the conventional magnetron sputtering apparatus shown in FIG.

As shown in FIGS. 1 and 2, the sputtering apparatus and the sputtering method in the first embodiment are characterized by the position and distance of the distance L ₁ toward the outer peripheral direction with reference to the axis passing through the rotation center 9 of the substrate holder 7. A plurality of sheets made of the same kind of film forming material at the position of L ₂ (> L ₁ ), having the same area, smaller than the area of the substrate holder 7 and electrically insulated via the insulating material 108 In this example, two targets 1a and 1b (inner target 1a and outer target 1b) are placed on the sputtering cathode 103 with the longitudinal direction of the targets 1a and 1b parallel to the radial direction of the substrate holder 7. provided further each target 1a, in that to be able to independently control the input power (sputtering power) P _1, P ₂ applied to 1b

  In the first embodiment, the lengths of the two targets 1a and 1b in the longitudinal direction are the same as the diameter of the substrate 8. However, the length may be not less than 0.5 times and not more than 1.5 times. This is because the target area is too small at 0.5 times or less and the film formation rate is slow, and the target area is too large at 1.5 times or more, resulting in an increase in the size of the sputtering apparatus itself.

  In addition, the intention of using the same size targets 1a and 1b is to simplify the configuration of the sputtering cathode 103 on which the targets 1a and 1b are arranged, to suppress the target cost during mass production, and to improve the maintainability. Because.

Here, when sputtering film formation is performed in the first embodiment, sputtered particles 12 are emitted from the two targets of the inner target 1 a and the outer target 1 b to the substrate 8 placed on the substrate holder 7. At this time, when the input power P ₁ and P ₂ from the sputtering power sources 112a and 112b connected to the inner target 1a and the outer target 1b are the same power, the inner and outer targets have the same area, so the substrate 8 is placed. In consideration of the rotation of the substrate holder 7 (rotation about the rotation center 9), the film thickness of the outer peripheral portion of the substrate 8 is different between the inner peripheral portion and the outer peripheral portion of the substrate 8 due to the difference in linear velocity in the rotational movement of the substrate 8. Becomes thinner, resulting in non-uniform film thickness within the substrate surface.

Therefore, in consideration of the above result, the power P ₁ input to the inner target _{1 a} and the power P ₂ input to the outer target ₁ b are adjusted (specifically, P ₁ <P ₂ ), respectively. The film thickness uniformity is improved.

  Furthermore, in the first embodiment, the magnetron sputtering cathode 103 in which two targets 1a and 1b having a smaller area than the size of the substrate 8 are used is used. There is no significant difference in the incident angle. That is, the uniformity of the film quality within the substrate surface is improved.

Next, in Embodiment 1, the distance from the axis passing through the rotation center 9 of the substrate holder 7 to the center line in the longitudinal direction of the inner target 1a is L ₁ , and the distance from the axis passing through the rotation center 9 to the longitudinal direction of the outer target 1b It is more preferable that the distance to the center line is L ₂ and the relationship between the input power P ₁ applied to the inner target 1a and the input power P ₂ applied to the outer target 1b is set within the range of the following formula (Equation 1). In addition, the film thickness uniformity in the substrate plane is further improved.

1 ≦ P ₂ / P ₁ ≦ (L ₂ ² −L ₁ ² ) / L ₁ ² (Equation 1)
Here, if the ratio of P ₂ / P ₁ is less than 1, the power P ₁ to be applied to the inner target _{1 a} is larger than the power P ₂ to be applied to the outer target ₁ b, so that sputtering per unit time reaching the substrate 8 is performed. In the substrate 8, the number of particles 12 is greater on the inner peripheral side than on the outer peripheral side. That is, the difference in linear velocity due to the rotational motion of the substrate 8 cannot be canceled out, and the film thickness correction effect on the inner and outer peripheries of the substrate 8 becomes insufficient, and as a result, the film thickness becomes thinner on the inner perimeter in the substrate surface.

Conversely, if _{^{(L 2 2 -L 1 2)}} / L 1 exceeds than ² ratio, for power _{P 2} to be introduced into the outer target 1b is too large than the power _{P 1} to be introduced inside the target 1a, it reaches the substrate 8 The number of sputtered particles 12 per unit time is too much on the outer peripheral side of the substrate 8 than on the inner peripheral side. This has an excessive effect of offsetting the difference in linear velocity in the rotational movement of the substrate, that is, the effect of correcting the film thickness at the inner and outer peripheries within the substrate surface, resulting in a thicker film thickness at the outer periphery within the substrate surface.

  In the first embodiment, two targets are used, but three or more targets may be arranged.

  Furthermore, the T / S distance (distance between the target and the substrate) of at least one of the plurality of targets arranged may be different from the T / S distance of other targets.

  In addition, at least one of the plurality of targets arranged may be arranged to be inclined at a certain angle with respect to the surface of the substrate holder 7.

  On the other hand, the substrate 8 on which the thin film is formed has a circular shape that is substantially the same size as that of the substrate holder 7 in the first embodiment. There is no limit to the number of sheets.

(Embodiment 2)
FIG. 3 is a schematic plan view showing the positional relationship between the target and the substrate of the sputtering apparatus according to Embodiment 2 of the present invention. In FIG. 3, the same components as those in FIGS. 1 and 9 to 17 used in the description of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The characteristics of the sputtering apparatus and sputtering method in the second embodiment are substantially the same as the sputtering cathode 103 in which the two inner and outer targets 1a and 1b that are the characteristics of the first embodiment are arranged, and are made of different film forming materials. It is that one more sputtering cathode replaced with a target is mounted.

Specifically, based on the axis passing through the rotation center 9 of the substrate holder 7 in FIG. 3, two target groups 1a of the sputtering cathode 103 of the first embodiment, 1b at the same position, i.e., at a distance L ₁ In other words, the inner target 1a ′ and the sputtering cathode 103 ′ in which the outer target 1b ′ is disposed through the insulating material 108 ′ at the same distance L ₂ (> L ₁ ) are installed.

  In addition, since the effect | action regarding the film thickness uniformity improvement in Embodiment 2 is the same as that of Embodiment 1, the description is abbreviate | omitted.

  When performing the sputtering film formation in the second embodiment, first, the sputtering film formation is performed by the sputtering cathode 103 in which the inner target 1a and the outer target 1b are arranged, and then the inner target 1a ′ made of different film forming materials and By performing sputtering film formation with the sputtering cathode 103 ′ on which the outer target 1 b ′ is disposed, it is possible to form a multilayer film having excellent film thickness and film quality uniformity within the substrate surface.

  Furthermore, by repeating the above process a plurality of times, it is possible to form a laminated film having excellent film thickness and film quality uniformity within the substrate surface.

  In the second embodiment, two types of film forming materials are used, but three or more types may be used as long as they can be installed in a layout by adjusting the size and number of sputtering cathodes.

  The other configurations are the same as those in the first embodiment.

(Embodiment 3)
4 is a schematic plan view showing a positional relationship between a target and a substrate of a sputtering apparatus according to Embodiment 3 of the present invention and a state in which a sputtering power source is connected to the target, and FIG. 5 is a schematic cross-sectional view taken along line AA in FIG. is there. 4 and 5, the same components as those in FIGS. 1 to 3 and FIGS. 9 to 17 are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIGS. 4 and 5, the sputtering apparatus and the sputtering method in the third embodiment are characterized in that the same kind of components are formed at a distance L ₁ from the axis passing through the rotation center 9 of the substrate holder 7 toward the outer circumferential direction. Five targets 1 a made of a film material and having the same area and smaller than the area of the substrate holder 7 are electrically insulated through an insulating material 108 in a line parallel to the radial direction of the substrate holder 7. arrangement has been made inside the target group in the state (1a) is provided, and the distance from the rotation center 9 of the substrate holder 7 toward the outer circumferential direction L ₂ (> L ₁₎ to the position of the inner target group (1a) The sputtering cathode 103 provided with the outer target group ( 1b ) in which the five targets 1 b are arranged under the same conditions as above is mounted.

Further, in the third embodiment, the distance L ₁ inner target group arranged in a row relative to the respective targets 1a of (1a) and connected at the target between the wirings 113, also in a row around the distance L ₂ Similarly, each target 1b of the arranged outer target group ( 1b ) is also connected by the inter-target wiring 113, so that sputtering powers P ₁ and P ₂ applied to both target groups ( 1a ) and ( 1b ) can be independently obtained. It is characterized in that it can be controlled.

In the third embodiment, the length in the longitudinal direction of each target group ( 1a ), ( 1b ) composed of five targets 1 a, 1 b is substantially the same as the diameter of the substrate 8. The length may be 5 times or less. This is because the target area is too small at 0.5 times or less and the deposition rate is slow, and the target area is too large at 1.5 times or more, resulting in an increase in the size of the sputtering apparatus itself.

  Further, the intention of using the same size targets 1a and 1b is to simplify the configuration of the sputtering cathode 103 on which the targets 1a and 1b are arranged, to suppress the target cost during mass production, and to improve the maintainability. Because.

Here, when performing the sputtering film formation in the third embodiment, the sputtered particles 12 are emitted from the inner target group ( 1a ) and the outer target group ( 1b ) to the substrate 8 placed on the substrate holder 7. However, at this time, when the input powers Pt ₁ and Pt ₂ from the sputtering power sources 112a and 112b connected to the inner target group ( 1a ) and the outer target group ( 1b ) are the same power, both target groups ( 1a ) , ( 1b ) have the same total area (5 targets 1 a and 1 b each having the same area), so that the substrate holder 7 on which the substrate 8 is placed rotates (rotates around the rotation center 9 of the substrate holder 7). ), The film thickness of the outer peripheral part of the substrate 8 becomes thin due to the difference in the linear velocity in the rotational movement of the substrate 8 between the inner peripheral part and the outer peripheral part of the substrate 8, and the film thickness becomes uneven in the substrate plane. Sex occurs.

Therefore, in consideration of this result, the power Pt ₁ input to the inner target group ( 1a ) and the power Pt ₂ input to the outer target group ( 1b ) are adjusted (specifically, Pt ₁ <Pt ₂ ). This improves the film thickness uniformity within the substrate surface.

Further, in the third embodiment, a magnetron sputtering cathode having a pair of target groups ( 1a ) and ( 1b ) in which five targets 1 a and 1 b each having a smaller area than the size of the substrate 8 are arranged. Since 103 is used, there is no significant difference in the incident angle of the sputtered particles 12 within the substrate surface. That is, it leads to the improvement of the uniformity of the film quality in the substrate surface.

  In addition, also in the sputtering film formation on the substrate 8 having a three-dimensional shape such as unevenness on the surface, the incident angle of the sputtered particles into the substrate surface is substantially uniform, so the film thickness at the stepped part or the inclined part is It leads to improvement of asymmetry.

Next, in Embodiment 3, the distance from the axis passing through the rotation center 9 of the substrate holder 7 to the center axis of the inner target group ( 1a ) is L ₁ , and the distance from the center axis of the outer target group ( 1b ) is and L _2, the input power Pt ₁ inwardly target group (1a), and an outer target group the relationship between the input power Pt ₂ to (1b), when installed in a range of the following expression (expression 2), further preferably The film thickness uniformity in the substrate surface is further improved.

1 ≦ Pt ₂ / Pt ₁ ≦ (L ₂ ² −L ₁ ² ) / L ₁ ² (Equation 2)
Here, when the ratio of Pt ₂ / Pt ₁ is less than ₁ , the power Pt ₁ to be input to the inner target group ( 1a ) is larger than the power Pt ₂ to be input to the outer target group ( 1b ). The number of sputtered particles 12 per hour is larger on the inner peripheral side of the substrate 8 than on the outer peripheral side. That is, the difference in linear velocity due to the rotational motion of the substrate 8 cannot be canceled out, and the film thickness correction effect on the inner and outer peripheries of the substrate 8 becomes insufficient, and as a result, the film thickness becomes thinner on the inner perimeter in the substrate surface.

Conversely, if _{^{(L 2 2 -L 1 2)}} / L 1 exceeds than ² ratio, too large than the power Pt ₁ power Pt ₂ to be introduced into the outer target group (1b) is turned inside the target group (1a) For this reason, the number of sputtered particles 12 per unit time reaching the substrate 8 is too much on the outer peripheral side of the substrate 8 than on the inner peripheral side. This is because the effect of canceling the difference in linear velocity in the rotational motion of the substrate 8, that is, the effect of correcting the film thickness at the inner and outer circumferences in the substrate surface becomes excessive, and as a result, the film thickness becomes thick at the outer circumference in the substrate surface. .

In the third embodiment, the number of targets 1a and 1b in each target group ( 1a ) and ( 1b ) is five on the inner and outer sides, but six or more may be arranged.

If the length of each target group ( 1a ), ( 1b ) arranged in a plurality of rows is 0.5 to 1.5 times the diameter of the substrate holder 7, as shown in FIG. The number of targets 1a and 1b for each target group ( 1a ) and ( 1b ) is different, such as five targets 1a for the inner target group ( 1a ) and four targets 1b for the outer target group ( 1b ). Furthermore, the target array may be arranged in a staggered pattern as shown in FIG.

  In addition, as long as the relationship of the above equation (Equation 2) is satisfied, the inter-target wiring 113 in each of the targets 1a and 1b may be changed as shown in FIG.

  It is also conceivable to make the target shape rectangular other than circular.

  Furthermore, the T / S distance of at least one target arranged in a plurality may be different from the T / S distance of other targets.

  In addition, at least one of the plurality of targets 1 a and 1 b disposed may be disposed at an angle with respect to the facing surface of the substrate holder 7.

  On the other hand, the substrate 8 on which the thin film is formed is also a circle having substantially the same size as that of the substrate holder 7 in the third embodiment, but the size that can be placed on the substrate holder 7 as in the first embodiment. If so, there is no limitation on the shape and the number of sheets.

(Embodiment 4)
FIG. 8 is a schematic plan view showing the positional relationship between the target and the substrate of the sputtering apparatus according to Embodiment 4 of the present invention. In FIG. 8, the same components as those in FIG. 4 used in the description of the third embodiment are denoted by the same reference numerals, and the description thereof is omitted.

The sputtering apparatus and the sputtering method according to the fourth embodiment are characterized by a sputtering cathode 103 in which two inner and outer target groups ( 1a ) and ( 1b ) each having five targets, which are the characteristics of the third embodiment, are arranged. Furthermore, another sputtering cathode replaced with a target made of a different film forming material is mounted.

Specifically, as shown in FIG. 8, the two target groups ( 1a ) and ( 1b ) of the sputtering cathode 103 of the third embodiment are symmetric with respect to an axis passing through the rotation center 9 of the substrate holder 7. , the distance _{L 1} of the inner target group in the position (1a ') and, likewise distance _{L 2} (> _{L 1)} outside the target group in the position of (1b'), and sputtering cathodes 103 arranged through the insulating material 108 ' Is to install. The targets 1a ′ and 1b ′ of the other target groups ( 1a ′) and ( 1b ′) are made of different film forming materials from the targets 1a and 1b of the target groups ( 1a ) and ( 1b ) of the third embodiment. Is.

  In addition, since the effect | action regarding the film thickness uniformity improvement in Embodiment 4 is the same as that of Embodiment 1, the description is abbreviate | omitted.

When performing sputtering film formation in the fourth embodiment, first, sputtering film formation is performed with the sputtering cathode 103 in which one inner target group ( 1a ) and one outer target group ( 1b ) are arranged, and then different film formations are performed. Sputtering film formation is performed at the sputtering cathode 103 ′ in which the other inner target group ( 1a ′) and outer target group ( 1b ′) made of the material are arranged, so that the film thickness (with respect to the three-dimensional shape object is reduced). It is possible to form a multilayer film having excellent film quality uniformity (including film thickness symmetry).

  Furthermore, by repeating the above process a plurality of times, it is possible to form a laminated film having excellent film thickness (including film thickness symmetry with respect to a three-dimensional shape) and film quality uniformity within the substrate surface.

  In the fourth embodiment, two types of film forming materials are used. However, three or more types may be used as long as they can be installed in a layout by adjusting the size and number of sputtering cathodes.

  The other configurations are the same as those in the third embodiment.

  The sputtering apparatus and the sputtering method of the present invention are small magnetron sputtering cathodes and can improve the uniformity of film thickness and film quality in the substrate surface of a thin film formed on a large substrate. It is possible to produce functional films used for optical filter films and various sensors with high yield and high quality without waste.

1a, 1b, 1a ', 1b' Targets ( 1a ), ( 1b ), ( 1a '), ( 1b ') Target group 7 Substrate holder 8 Substrate 9 Center of rotation of substrate holder 12 Sputtered particles 103, 103 'Sputtering cathode 108 , 108 'Insulating material 112a, 112b Sputtering power supply 113 Inter-target wiring

Claims (14)

A vacuum chamber having an exhaust system and a gas introduction system, a sputtering cathode installed in the vacuum chamber and having a target, a rotatable substrate holder on which a substrate is placed, and a sputtering device connected to the sputtering cathode In a sputtering apparatus equipped with a power source,
A sputtering apparatus, wherein a plurality of targets made of the same kind of film forming material and smaller than the area of the substrate holder are electrically insulated and installed on the sputtering cathode.   2. The sputtering apparatus according to claim 1, wherein in the sputtering cathode, sputtering power input to at least one of the targets can be controlled independently of the other targets.   A plurality of the targets having a rectangular shape with the same length of the same area as the film-forming material having a length in the longitudinal direction of 0.5 to 1.5 times the diameter of the substrate holder, The sputtering apparatus according to claim 1, wherein a direction is provided in parallel to the radial direction of the substrate holder and is provided in the sputtering cathode.   The sputtering power applied to the target disposed outside the rotation center of the substrate holder in the plurality of targets is made larger than the sputtering power applied to the target disposed inside. 3. The sputtering apparatus according to 3. The distances from the rotation center of the substrate holder to the center line of each target are L _n and L _{n + 1} (where L _n <L _{n + 1} ), and the sputtering power input to each target is P _n and P _{n + 1} , respectively. 5. The sputtering apparatus according to claim 4, wherein the condition of the following formula (Equation 1) is satisfied.
1 ≦ P _{n + 1} / P _n ≦ (L _{n + 1} ² −L _n ² ) / L _n ² (Equation 1)   The length in the longitudinal direction is not less than 0.5 times and not more than 1.5 times the diameter of the substrate holder, and a plurality of targets having the same kind of film forming material and the same area are parallel to the radial direction of the substrate holder. The sputtering apparatus according to claim 1, wherein a plurality of target groups arranged in a single line are provided on the sputtering cathode.   In the plurality of rows of target groups, the total sputtering power to be applied to the target group disposed outside the rotation center of the substrate holder is larger than the total sputtering power to be applied to the target group disposed inside. The sputtering apparatus according to claim 6. The distance from the rotation center of the substrate holder to the center line of each target group is L _m , L _{m + 1} (where L _m <L _{m + 1} ), and the total sputtering power input to each target group is Pt _m , Pt _{m + 1} , the following equation (Equation 2) is satisfied: 8. The sputtering apparatus according to claim 7,
1 ≦ Pt _{m + 1} / Pt _m ≦ (L _{m + 1} ² −L _m ² ) / L _m ² (Equation 2)   The sputtering apparatus according to claim 6, wherein each target of the target group is a planar circular body.   Each sputtering target of the said target group is a planar rectangular body, The sputtering device of any one of Claims 6-8 characterized by the above-mentioned.   The sputtering apparatus according to claim 1, wherein at least one of the plurality of targets and another target are set to have different distances from the facing surface of the substrate holder.   The sputtering apparatus according to any one of claims 1 to 11, wherein at least one surface of the plurality of targets is installed to be inclined with respect to a facing surface of the substrate holder.   The sputtering apparatus according to claim 1, further comprising a sputtering cathode provided with a plurality of targets of a film forming material different from the material of the target.   A thin film is formed on a substrate placed on a substrate holder by magnetron discharging a plurality of targets provided on the sputtering cathode and rotating the substrate holder using the sputtering apparatus according to claim 1. A sputtering method characterized by:

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