Film deposition apparatus and film deposition method

Abstract

To provide a film deposition apparatus and a film deposition method capable of suppressing a non-erosion region produced in a magnetron sputtering.SOLUTION: A film deposition apparatus according to the present invention includes a chamber, a rotary target, a magnet, and a floating shield. The rotary target is arranged in the chamber, has a cylindrical target surface around a center axis, and a first length along the center axis. The magnet is extended along the center axis, has a second length along the center axis, and forms a magnetic field on a target surface. The floating shield has a floating potential across the rotary target in a direction along the center axis. When a third length is a length between positions along the center axis where a vertical magnetic field component of the magnet is zero on the target surface is a third length, the third length is shorter than the first length.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a film formation apparatus and a film formation method by magnetron sputtering using a rotary target. [Background technology]

[0002] In sputtering, a sputtering gas is introduced into a vacuum and then turned into plasma by discharging the sputtering gas, and the ions generated collide with a target to generate sputter particles, which are then deposited on the object to be deposited. In magnetron sputtering, a magnet placed near the target is used to surround electrons in a magnetic field, creating a high-density plasma region near the target, and the ions are efficiently collided with the target, making it possible to speed up deposition (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-200520 A Summary of the Invention [Problem to be solved by the invention]

[0004] Here, in a magnetron sputtering device such as that described in Patent Document 1, the "non-erosion region" of the target becomes a problem. The non-erosion region is a region of the target where erosion (erosion by plasma) does not occur. Sputtered particles accumulate in the non-erosion region, and when they peel off, they become particles and adhere to the object to be film-formed, etc., which has a significant impact on product yield. Furthermore, when a non-erosion region occurs, the consumption of the target becomes uneven, and the utilization efficiency of the target also decreases.

[0005] In view of the above circumstances, an object of the present invention is to provide a film formation apparatus and a film formation method capable of suppressing the non-erosion region that occurs in magnetron sputtering. [Means for solving the problem]

[0006] In order to achieve the above object, a film formation apparatus according to one aspect of the present invention includes a chamber, a rotary target, a magnet, and a floating shield. The rotary target is disposed within the chamber and has a cylindrical target surface about a central axis and a first length along the central axis. The magnet extends along the central axis, has a second length along the central axis, and generates a magnetic field on the target surface. The floating shield sandwiches the rotary target in a direction along the central axis and has a floating potential. If a length along the central axis between positions on the target surface where the perpendicular magnetic field component of the magnet is zero is defined as a third length, the third length is shorter than the first length.

[0007] The difference between the first length and the third length may be less than 53 mm.

[0008] The difference may be greater than 15 mm.

[0009] The difference may be equal to or greater than 20 mm and equal to or less than 31 mm.

[0010] If the thickness of the rotary target in a direction perpendicular to the central axis is a first thickness, and the thickness of the floating shield in a direction perpendicular to the central axis is a second thickness, the second thickness may be greater than or equal to the first thickness.

[0011] The difference between the first thickness and the second thickness may be less than 10 mm.

[0012] In order to achieve the above-mentioned object, a film formation method according to one embodiment of the present invention comprises: a chamber; a rotary target disposed within the chamber, having a cylindrical target surface around a central axis and having a first length along the central axis; a magnet extending along the central axis and having a second length along the central axis, forming a magnetic field on the target surface; and a floating shield sandwiching the rotary target in a direction along the central axis and having a floating potential, wherein, when a length along the central axis between positions on the target surface where a vertical magnetic field component of the magnet is zero is defined as a third length, the third length is shorter than the first length, and a difference between the first length and the third length is less than 53 mm, and sputtering film formation is performed on a film formation target using a film formation apparatus. Effect of the Invention

[0013] As described above, according to the present invention, it is possible to provide a film formation apparatus and a film formation method capable of suppressing non-erosion regions that occur in magnetron sputtering. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic diagram of a film forming apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of the film forming apparatus. [Diagram 3] FIG. 2 is a perspective view of a target mechanism included in the film forming apparatus. [Figure 4] FIG. 2 is a cross-sectional view of the target mechanism. [Diagram 5] 3 is a schematic diagram showing an arrangement of magnets in the target mechanism. FIG. [Figure 6] 3 is a schematic diagram showing a rotary target and a magnet in the target mechanism. FIG. [Figure 7] 2 is a cross-sectional view of a target mechanism and a floating shield included in the film forming apparatus. FIG. [Figure 8] 4 is a schematic diagram showing a perpendicular magnetic field component of a magnet in the target mechanism. FIG. [Figure 9]FIG. 2 is a schematic diagram of magnetron sputtering using the above-mentioned film forming apparatus. [Figure 10] 4 is a schematic diagram showing a non-erosion region formed in a rotary target of the target mechanism. FIG. [Figure 11] 1 is a graph showing measurement results according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] [About the deposition equipment] A film formation apparatus according to this embodiment will be described. Figures 1 and 2 are schematic diagrams of a film formation apparatus 100 according to this embodiment. As shown in Figures 1 and 2, the film formation apparatus 100 includes a vacuum chamber 101, a target mechanism 102, a floating shield 103, an end protection plate 104, a rear protection plate 105, a gas introduction unit 106, a substrate holder 107, and a drive control unit 108. A substrate S, which is an object to be film-formed, is attached to the substrate holder 107.

[0017] Vacuum chamber 101 defines therein a sputtering space 111. A gas supply system 112 and an exhaust system 113 are connected to vacuum chamber 101. Gas supply system 112 is connected to gas inlet 106 and supplies sputtering gas to gas inlet 106. Exhaust system 113 is connected to a vacuum pump (not shown) and evacuates sputtering space 111 to a vacuum.

[0018] The target mechanism 102 is disposed in the sputtering space 111 and generates sputtered particles. FIG. 3 is a perspective view of the target mechanism 102, and FIG. 4 is a cross-sectional view of the target mechanism 102. As shown in FIG. 3, the target mechanism 102 extends along a central axis C (Z direction). As shown in FIG. 2, the film forming apparatus 100 has a plurality of target mechanisms 102, and the number of the target mechanisms 102 is not particularly limited. The target mechanisms 102 are disposed such that their respective central axes C are parallel to each other. The film forming apparatus 100 may also include only one target mechanism 102.

[0019] 4, the target mechanism 102 includes a backing tube 121, a rotary target 122, and a magnet unit 123. The backing tube 121 has a cylindrical shape centered on a central axis C. The backing tube 121 is connected to a sputtering power supply 131 (see FIG. 1) and functions as a cathode.

[0020] The rotary target 122 is stacked on the outer peripheral surface of the backing tube 121 and configured to be rotatable around the central axis C by a rotation mechanism (not shown). The rotary target 122 has a cylindrical target surface 122a around the central axis C. Hereinafter, as shown in FIG. 3, an end of the rotary target 122 in the extension direction (Z direction) of the central axis C is referred to as an end 122b. The rotary target 122 is made of a target material, and the target material is, for example, Mo or ITO (Indium Tin Oxide). In addition, the target material may be Al, Ti, Cu, W, Ag, IGZO (Indium Gallium Zinc Oxide), IZO (Indium Zinc Oxide), ITO (Indium Tin Oxide), IAZO (Indium Aluminum Zinc Oxide), IATO (Indium Aluminum Tin Oxide), or other materials.

[0021] The magnet unit 123 is disposed in the backing tube 121 as shown in Fig. 4, and is configured to be rotatable about the central axis C by a rotation mechanism (not shown). As shown in the figure, the magnet unit 123 includes a yoke 124 and a magnet 125. The magnet 125 extends along the central axis C and forms a magnetic field on the target surface 122a. Specifically, the magnet 125 includes an N-pole magnet 126 and an S-pole magnet 127, and the N-pole magnet 126 and the S-pole magnet 127 are disposed so as to face the rotary target 122 from inside the backing tube 121.

[0022] 5 is a schematic diagram showing the arrangement of magnets 125 in the target mechanism 102. As shown in the figure, the N-pole magnet 126 surrounds the S-pole magnet 127, and the N-pole magnet 126 and the S-pole magnet 127 extend along the central axis C (Z direction). Note that the magnetic poles of the N-pole magnet 126 and the S-pole magnet 127 may be opposite.

[0023] 6 is a schematic diagram showing the rotary target 122 and the magnet 125. As shown in the figure, the length along the central axis C of the rotary target 122 is defined as a first length L1, and the length along the central axis C of the magnet 125 is defined as a second length L2. In addition, the second length L2 may be longer than, shorter than, or the same as the first length L1.

[0024] The first length and the second length L2 can be changed according to the length of the substrate S. For example, when the length along the central axis C of the substrate S is 2620 mm, the first length L1 can be 3106 mm, and the second length L2 can be 3070 to 3126 mm. In addition, if the distance between the rotary target 122 and the magnet 125 is distance M as shown in FIG. 6, distance M is, for example, 22 to 40 mm.

[0025] Hereinafter, the portion of the magnet 125 located inside the rotary target 122 will be referred to as the first portion 125a, and the portions provided on both ends of the first portion 125a and located outside the rotary target 122 will be referred to as the second portion 125b. Specifically, as shown in Fig. 5, the first portion 125a can include an N-pole magnet 126 and an S-pole magnet 127, and the second portion 125b can include an end portion of the N-pole magnet 126. In addition, the end portion of the magnet 125 will be referred to as an end portion 125c.

[0026] The floating shield 103 is disposed at both ends of each target mechanism 102 and has a floating potential. Fig. 7 is a cross-sectional view of the vicinity of the floating shield 103 of the film forming apparatus 100. As shown in the figure, the floating shield 103 has a cylindrical shape and is disposed around the backing tube 121 at the end of the target mechanism 102. The floating shield 103 is separated from the backing tube 121 and is insulated from the backing tube 121. Although Fig. 7 shows one end of the target mechanism 102, a similar floating shield 103 is provided at the opposite end.

[0027] The floating shield 103 has a thickness equal to or greater than that of the rotary target 122. As shown in FIG. 7, the thickness of the rotary target 122 in a direction perpendicular to the central axis C (direction in the XY plane) is defined as a first thickness T1. The first thickness T1 is, for example, 10 mm. The thickness of the floating shield 103 in the same direction is defined as a second thickness T2. The second thickness T2 is equal to or greater than the first thickness T1. If the difference between the second thickness T2 and the first thickness T1 is defined as difference ΔT, then it is preferable that difference ΔT be smaller than 10 mm. In other words, it is preferable that difference ΔT be 0 mm≦ΔT<10 mm.

[0028] 1, the end protection plate 104 is disposed between the end of the target mechanism 102 and the inner wall of the vacuum chamber 101, and prevents the adhesion of sputtered particles to the inner wall of the vacuum chamber 101. The end protection plate 104 is also connected to a sputtering power supply 131 and functions as an anode.

[0029] The rear adhesion shield 105 is disposed between the inner wall of the vacuum chamber 101 on the side opposite to the substrate S and the target mechanism 102, and prevents sputtering particles from adhering to the vacuum chamber 101. The rear adhesion shield 105 is also connected to a sputtering power supply 131 and functions as an anode.

[0030] Gas inlet 106 discharges sputtering gas supplied from gas supply system 112 (see FIG. 1) into sputtering space 111. This sputtering gas includes a sputtering gas and a reactive gas. The sputtering gas is a gas that is ionized by discharge, such as Ar. The reactive gas is a gas that undergoes a chemical reaction with particles of the target material resulting from the collision of the ions, such as O2. Gas inlet 106 may be provided on rear adhesion shield 105 as shown in FIG. 2, or may be provided at another position within sputtering space 111.

[0031] The substrate holder 107 is provided in the sputtering space 111 and holds the substrate S. The configuration of the substrate holder 107 is not particularly limited as long as it is capable of holding the substrate S. A floating mask that covers the peripheral portion of the substrate S may be provided on the peripheral portion of the substrate S.

[0032] The drive control unit 108 includes a sputtering power supply 131 and a rotation drive source 132. The sputtering power supply 131 is a power supply for discharging power supplied to the target mechanism 102, and may be a DC (Direct Current) power supply or a high-frequency power supply such as an RF (Radio Frequency) power supply or a VHF (Very High Frequency) power supply. The rotation drive source 132 drives a rotation mechanism of the rotary target 122 and the magnet unit 123, and controls the rotation angle of the magnet unit 123.

[0033] The film forming apparatus 100 has the above-mentioned configuration. The film forming apparatus 100 may have other configurations instead of or in addition to the above-mentioned configurations.

[0034] [Regarding the perpendicular magnetic field component of a magnet] It is preferable that the distance between positions where the vertical magnetic field component of magnet 125 is 0 (B⊥0) is shorter than the first length L1. Fig. 8 is a schematic diagram showing the vertical magnetic field component of magnet 125. In this figure, the positions where the vertical magnetic field component of magnet 125 is 0 are shown as line B⊥0.

[0035] Furthermore, the length along the central axis C between the positions (between lines B) on the target surface 122a where the vertical magnetic field component is zero is defined as a third length L3. This third length L3 is preferably shorter than the first length L1. Moreover, the difference between the first length L1 and the third length L3 is defined as a difference ΔL. As shown in FIG. 8, the difference ΔL is the sum of the differences ΔL / 2 on one side of the rotary target 122. The difference ΔL is preferably in the range of more than 15 mm and less than 53 mm, that is, 15 mm<ΔL<53 mm. Furthermore, the difference ΔL is more preferably in the range of 20 mm to 31 mm, that is, 20 mm≦ΔL≦31 mm.

[0036] [Film formation method] A film formation method using the film formation apparatus 100 will be described. Fig. 9 is a schematic diagram showing the film formation method using the film formation apparatus 100. In this film formation method, first, the sputtering space 111 is evacuated to a vacuum by the exhaust system 113 (see Fig. 1). After the sputtering space 111 is sufficiently depressurized, a sputtering gas is released from the gas inlet .

[0037] Next, while rotating the rotary target 122 provided in each target mechanism 102, the supply of discharge power to each target mechanism 102 is started. The sputtering gas is converted into plasma by this discharge power. This plasma is confined within the magnetic field generated by the magnet 125, forming a high-density plasma P as shown in FIG.

[0038] The ions forming the high-density plasma P collide with the target surface 122a, scattering sputtered particles, which are particles of the target material. The scattered sputtered particles react with the reactive gas and deposit on the substrate S to form a film. The supply of discharge power is continued in this manner until the film thickness reaches the desired thickness. During film formation, the magnet unit 123 is swung around the central axis C (see FIG. 4) to change the orientation of the high-density plasma P, making it possible to uniformize the film quality and film thickness distribution.

[0039] The above is how the film is formed by the film forming apparatus 100. The above-described film forming process may be performed by a user using the film forming apparatus 100, or may be performed by the drive control unit 108 controlling the sputtering power supply 131 and the rotation drive source 132.

[0040] [Non-erosion area] In magnetron sputtering using the film forming apparatus 100 as described above, non-erosion regions may be formed on the rotary target 122. Fig. 10 is a schematic diagram showing the non-erosion region R. As shown in the figure, the non-erosion region R is formed on both ends of the rotary target 122. The width of the non-erosion region R along the central axis C (Z direction) is defined as width H.

[0041] This non-erosion region R is a region where erosion (erosion by plasma) does not occur in the target. Sputtered particles accumulate in the non-erosion region R, and when they peel off, they become particles and adhere to the substrate S, etc., which has a significant impact on the product yield. In addition, when the non-erosion region R occurs, the rotary target 122 is worn unevenly, and the utilization efficiency of the rotary target 122 also decreases.

[0042] Here, in the film forming apparatus 100, a case will be described in which the length of the magnet 125 (second length L2) is longer than the length of the rotary target 122 (first length L1), and the magnet 125 has a second portion 125b located outside the rotary target 122 (see FIG. 6). The length of the magnet 125 (second length L2) may be the same as or shorter than the length of the rotary target 122 (first length L1). With this configuration, the high-density plasma P (see FIG. 9) spreads to the end of the rotary target 122, making it possible to suppress the non-erosion region R.

[0043] Furthermore, in the film forming apparatus 100, it is preferable that the length (third length L3) between the positions (B⊥0) where the perpendicular magnetic field component is 0 is shorter than the first length L1, and the difference ΔL between the first length L1 and the third length L3 is greater than 15 mm and smaller than 53 mm. The position (B⊥0) where the perpendicular magnetic field component is 0 is the position where the sputtering rate is the highest. The sputtering rate means the statistical probability value of the number of atoms that fly out of the rotary target 122 when one ion collides with the rotary target 122. Therefore, the non-erosion region R can be controlled by adjusting the difference ΔL.

[0044] Specifically, when the difference ΔL is 53 mm or more, the high-density plasma P is separated from the floating shield 103, and the non-erosion region R becomes larger (see the Examples). On the other hand, when the difference ΔL is 15 mm or less, the high-density plasma P approaches the floating shield 103, and an arc discharge occurs between the floating shield 103 and the rotary target 122 (see the Examples). Therefore, the difference ΔL is preferably in the range of more than 15 mm and less than 53 mm, and more preferably in the range of 20 mm to 31 mm.

[0045] Regarding the thickness of the rotary target 122 (first thickness T1) and the thickness of the floating shield 103 (second thickness T2), the second thickness T2 is equal to or greater than the first thickness T1, and the difference ΔT (see FIG. 7) therebetween is preferably equal to or greater than 0 mm and less than 10 mm. If the second thickness T2 is smaller than the first thickness T1, sputtered particles will adhere to the end surface of the rotary target 122 and become particles. On the other hand, if the difference ΔT is equal to or greater than 10 mm, high-density plasma P will not be generated at the end of the rotary target 122, and the non-erosion region R will become large. Therefore, the difference ΔT is preferably equal to or greater than 0 mm and less than 10 mm.

[0046] From the above, by setting the difference ΔL (see FIG. 8) in the range of more than 15 mm and less than 53 mm, the non-erosion region R can be further suppressed. In addition, by setting the difference ΔT (see FIG. 7) to be 0 mm or more and less than 10 mm, the non-erosion region R can also be further suppressed. It is most preferable to set the difference ΔL to be more than 15 mm and less than 53 mm, and the difference ΔT to be 0 mm or more and less than 10 mm.

[0047] [Embodiments of the present invention] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. At least two of the characteristic parts described in the above embodiment can be arbitrarily combined. EXAMPLES

[0048] A film forming apparatus according to an embodiment of the present invention was fabricated, and various measurements were performed. The following [Table 1] and [Table 2] are tables showing the measurement results. The first length L1, the difference ΔL (see FIG. 8), and the difference ΔT (see FIG. 7) were the values ​​shown in Tables 1 and 2.

[0049] For the deposition apparatus according to each embodiment, magnetron sputtering was performed using Mo and ITO as target materials, and the width H of the non-erosion region (see FIG. 10) was measured. The width H is shown in Tables 1 and 2. Also, FIG. 11 is a graph plotting the sum (2H) of the width H of the non-erosion region at both ends of the rotary target against the difference ΔL.

[0050] [Table 1]

[0051] [Table 2]

[0052] As shown in Fig. 11, the width 2H of the non-erosion region is suppressed in Examples 1 to 9. Among them, when the difference ΔL is 53 mm (Example 2), the width 2H of the non-erosion region is 36 mm (18 mm x 2), so the difference ΔL is preferably in a range smaller than 53 mm. Also, when the difference ΔL is 15 mm (Example 5), no non-erosion region was generated, but an arc discharge occurred between the floating shield and the rotary target, so the difference ΔL is preferably in a range larger than 15 mm. Therefore, the difference ΔL is preferably in a range larger than 15 mm and smaller than 53 mm.

[0053] Furthermore, when the difference ΔL is 20 mm (Example 4) and 31 mm (Example 3), neither a non-erosion region nor arc discharge occurs, and the difference ΔL is preferably 20 mm or more and 31 mm or less. Regarding the difference ΔT, when the difference ΔT is 5 mm (Examples 6 and 7), no non-erosion region occurs, as in the case where the difference ΔT is 0 mm (Examples 3 and 4). On the other hand, when the difference ΔT is 10 m (Examples 8 and 9), the non-erosion region 2H is 20 mm. Therefore, a range of the difference ΔT less than 10 mm is preferable. [Explanation of symbols]

[0054] 100...Film deposition equipment 101...Vacuum chamber 102...Target mechanism 103…Floating Shield 104...End adhesion prevention plate 105...Back attachment prevention plate 121…Backing tube 122...Rotary target 123...Magnet unit 124…York 125…Magnet

Claims

1. A chamber; a rotary target disposed within the chamber, the rotary target having a cylindrical target surface about a central axis and having a first length along the central axis; a magnet extending along the central axis and having a second length along the central axis to form a magnetic field on the target surface; a floating shield having a floating potential and sandwiching the rotary target in a direction along the central axis; Equipped with A film forming apparatus in which a length along the central axis between positions on the target surface where the perpendicular magnetic field component of the magnet is zero is defined as a third length, and the third length is shorter than the first length.

2. The film forming apparatus according to claim 1 , The difference between the first length and the third length is less than 53 mm. Film deposition equipment.

3. The film forming apparatus according to claim 2, The difference is greater than 15 mm Film deposition equipment.

4. The film forming apparatus according to claim 3, The difference is equal to or greater than 20 mm and equal to or less than 31 mm. Film deposition equipment.

5. The film forming apparatus according to claim 1 , A thickness of the rotary target in a direction perpendicular to the central axis is defined as a first thickness, and a thickness of the floating shield in a direction perpendicular to the central axis is defined as a second thickness, the second thickness being equal to or greater than the first thickness. Film deposition equipment.

6. The film forming apparatus according to claim 5 , The difference between the first thickness and the second thickness is less than 10 mm. Film deposition equipment.

7. a chamber; a rotary target disposed within the chamber, the rotary target having a cylindrical target surface around a central axis and a first length along the central axis; a magnet extending along the central axis, the magnet having a second length along the central axis, and forming a magnetic field on the target surface; and floating shields sandwiching the rotary target in a direction along the central axis and having a floating potential; When a length along the central axis between positions on the target surface where the perpendicular magnetic field component of the magnet is zero is defined as a third length, the third length is shorter than the first length. A film formation apparatus is used to perform sputtering film formation on a film formation target. Film formation method.

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