JP2617439B2 - Sputtering equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus and, more particularly, to a structure of a sputtering electrode for forming a thin film in a vacuum, and a uniform thin film having a uniform thickness on a substrate having a relatively large area. And a sputtering apparatus provided with a sputtering electrode that effectively consumes the entire target surface to be used.

[0002]

2. Description of the Related Art In a conventional sputtering apparatus, various types of electrode structures used for producing a thin film have been proposed.
Among them, the magnetron type electrode structure is most often used industrially. The reason is that the film formation speed is high. There are also a great variety of magnetron type electrodes. These electrodes are, for example, the "Thin Film Process".
) "(Academic Press Publishing, 1978, JLV
ossen and W. Kern), pages 75-173, or pages 186-189 of the "Thin Film Handbook" (published in 1983, edited by the 131st Committee of the Japan Society for the Promotion of Science, Thin Film Committee 131).
It is described on the page. Among these magnetron type electrodes, at present, a planar magnetron (Planar Magnetron) cathode electrode provided with a target having a planar shape is most useful industrially.

[0003]

Conventionally, when a thin film is formed on a large-area substrate by a sputtering apparatus using a rectangular magnetron cathode electrode having a rectangular shape, the following problems arise. Be raised. (1) Enlargement of apparatus (2) Economical cost due to non-uniform consumption of target (3) Non-uniformity of sputtered film in substrate due to non-uniform ion bombardment on target surface and non-uniformity of plasma spatial density distribution (4) Generation of particles due to non-uniform ion bombardment on the target surface Each of the above problems will be described below.

[0004] (1) Problem of Enlargement of Apparatus In a sputtering apparatus, the relative positional relationship between a substrate and a target is described in, for example, “Dry Process Application Technology” (Haruhiro Kobayashi, Takashi Okada, Naoyoshi Hosokawa, Nikkan Kogyo Shimbun) Publishing, 1984), pages 63 and 64. Usually, when forming a thin film on a large area substrate,
A substrate translation method is employed. The substrate translation method is a method in which a thin film is formed by performing sputtering while transporting a substrate along a plane parallel to a target inside a sputtering apparatus in which a rectangular target is arranged. For example, Japanese Patent Publication No. 63-65454 discloses a configuration example of a substrate-parallel type sputtering apparatus incorporating a rectangular magnetron cathode electrode. In such a substrate translation type sputtering apparatus, the transport direction of the substrate is selected in a direction parallel to the short side of the rectangular target in order to obtain a uniform film thickness. In general, when a substrate is transferred while being formed, when the size of the substrate is larger than the length of the short side of the target, the transfer distance of the substrate is sufficient to form a thin film having a uniform thickness on the substrate. Need to be large. From this demand and, in addition, the need to increase productivity,
The size of a substrate translation type sputtering apparatus for a large substrate tends to be huge. For example, the width of 700 m of the model name of ILC-3960S, which has been commercialized by the present applicant.
m, a sputtering apparatus for producing a thin film having a uniform thickness within ± 10% on a glass substrate having a height of 680 mm,
A magnetron cathode electrode having a flat plate target having a short side length of 250 mm and a long side length of 864 mm;
Film formation is performed by combining a tray having a height of 0 mm and a height of 830 mm. Further, while maintaining and managing the sputtering chamber in a vacuum state continuously, a load lock mechanism for inserting a non-processed substrate from the atmosphere side and pushing out a film-processed substrate to the atmosphere side, and film formation. Due to the necessity of a heating zone for providing a function of heating the previous substrate and a buffer space for transporting the tray almost continuously, the length of the entire apparatus reaches 10 m to 20 m.

(2) The problem of uneconomicity due to non-uniform consumption of the target In the magnetron cathode electrode, as described in the above-mentioned documents, the target surface is subjected to non-uniform ion bombardment. I do. This occurs due to the use of an essentially non-uniform magnetic field formed near the target surface at the magnetron cathode electrode. Conventionally, in order to improve the uneconomicity and the film thickness distribution accompanying the non-uniform consumption of the target, for example, in the case of a cylindrical coaxial magnetron cathode electrode and a circular plate magnetron cathode electrode, the position of the magnet assembly provided in the cathode electrode Is changed over time (Japanese Patent Publication No. 55-27627, Japanese Unexamined Patent Publication No. 3-6372).
No.). This device configuration is a technology unique to an electrode having a rotationally symmetric structure. Therefore, according to this apparatus configuration, particularly in the case of a circular flat magnetron cathode electrode, the consumption of the target can be made more uniform by rotating the magnet assembly around a certain rotation axis. On the other hand,
Such an apparatus configuration is not an effective technique as a means for uniformly consuming a flat rectangular target.

(3) Inhomogeneity of sputtered film on substrate The non-uniformity of ion bombardment on the target surface of the magnetron cathode electrode is not only uneconomical of the target utilization but also the quality of the film formed on the substrate. Affects homogeneity. An example of this effect will be described based on the above-mentioned JP-B-63-65754, in which a thin film is formed by a combination of a rectangular magnetron cathode electrode and a substrate translation type sputtering apparatus. When a voltage is applied between the cathode electrode and the wall of the vacuum vessel to discharge in a vacuum and form a film by sputtering, a rectangular tunnel path formed by magnetic flux lines is formed on the surface of the flat target of the cathode. The electron drifts along it and draws a single closed trajectory. The drift electrons collide with gas molecules and ionize, so a dense plasma is formed along the closed trajectory drawn by the drift electrons.
The target surface immediately below the locus drawn by the drift electrons is sputtered by receiving a strong ion bombardment. In practice, the number of electrons drifting is extremely large, so that the trajectory is a closed band having a certain width (having a road-like or groove-like shape). Therefore, the plasma formed along the band is the same, and the region to be sputtered on the target surface is also a band-shaped region having a width. The substrate placed on the translationally transferred tray passes through the space in front of the target for film formation.
Accordingly, a specific location on the substrate passes across a high plasma density space above two of the sputtering zone regions parallel to the long sides of the rectangular target. As is well known, sputtered atoms are emitted in various directions, not just in the direction perpendicular to the target surface. Therefore, at a specific location on the substrate, sputtered particles begin to deposit long before reaching the space above the sputtering zone, and the deposition rate increases as approaching the upper space of the first sputtering zone, immediately above it. , Once the deposition rate reaches the maximum value. Further, the transfer speed of the tray once decreases the deposition rate at a specific location on the substrate, but increases as the space approaches the upper space of the second sputtering zone, and the second deposition rate immediately above the sputtering zone. It will be the maximum value. Subsequent transfer of the tray
As the substrate moves away from the frontal space of the target, the deposition rate at a particular location on the substrate monotonically decreases. As described above, when paying attention to a specific fixed portion on the substrate surface, the deposition rate changes with time. Further, the incident angle of the sputtered particles deposited on the substrate surface changes greatly with time, and the plasma density in the space in contact with the substrate surface also changes greatly. As a result, when attention is paid to a specific portion on the substrate, a thin film finally formed on the substrate may have different physical characteristics in the thickness direction of the film.

(4) Problem of Particle Generation The non-uniformity of ion bombardment on the target surface of the magnetron cathode electrode further causes the generation of particles during film formation. As described above, on the target surface on the rectangular magnetron cathode electrode, one closed band-like region having a width smaller than the width of the target is subjected to ion bombardment and sputter-etched. Other areas on the target surface are not only sputter-etched, but also sputtered atoms scattered by multiple collisions with gas molecules in the space emerging from the target are deposited thereon. When the sputtering is continued for a long time, a sputtered film is formed on the target surface other than the strip-shaped region to be sputtered. As the thickness of the sputtered film deposited on the target increases, the sputtered film spontaneously peels off and becomes particles due to its internal stress. Particles are considered to be one of the biggest factors in reducing non-defective products when processing thin films on substrates into fine patterns for use as electronic components. Is desired.

In view of the above problems (1) to (4), the present inventors have previously disclosed a sputtering apparatus provided with a magnetron cathode electrode having a structure capable of solving these problems. 194298. In this sputtering apparatus, as one example, a magnet assembly including a plurality of magnet units and a magnetron cathode electrode provided with a moving mechanism for reciprocating the magnet assembly are shown. Each of the plurality of magnet units generates a rectangular annular electron drift motion trajectory on the surface of the target based on the electron constraining action of the electromagnetic field, corresponding to the planar shape formed by the center magnetic pole and the peripheral magnetic pole. . In the adjacent magnet units, the arrangement relationship of the magnetic poles is reversed, so that the movement direction of the electrons in the electron drift movement trajectory is reversed. Then, the magnet assembly is vibrated in parallel with the target surface by the moving mechanism, thereby increasing the uniformity of the deposition rate of the film formed on the substrate and widening the etching area of the target.

[0009] The above-mentioned sputtering apparatus proposed by the present inventors further has the following points to be improved. When each of the plurality of magnet units constituting the magnet assembly is dimensionally the same size and the center position is located at the same position in the direction orthogonal to the movement direction,
The amount of spatter at the short side of the rectangular annular electron drift motion trajectory generated by each magnet unit is greater than the amount of spatter at the long side. Because the direction of the center line formed by connecting the center positions of the respective circular electron drift motion trajectories is set in the direction of the reciprocating motion, and the short side is set in parallel with the direction of the reciprocating motion. This is because the target region corresponding to the portion will be sputter-etched at a substantially higher plasma density than the target region corresponding to the long side portion. Thus, the amount of sputter per unit time at one point of the target portion sputter-etched on the short side is smaller than the amount of sputter per unit time at one point of the target portion sputter-etched on the long side. More. In other words, the sputter amount distribution in the direction perpendicular to the direction of the reciprocating motion is such that the sputter etching is uniformly performed from the center position defined by the long side direction to the vicinity of the short side portion, while the electron drift motion trajectory is short. At the side portions, the sputter etching amount is greatly increased. In view of the consumption of the target, the edge region of the target corresponding to the short side consumes more than the central region. Therefore, the life of the target is determined by the degree of wear of the edge portion, and as a result, there is a problem that the utilization efficiency of the target is reduced.

An object of the present invention is to further provide a sputtering apparatus having an electrode structure for forming a thin film on a relatively large rectangular substrate in a stationary state, instead of a translational transfer method, as proposed by the present inventors. It is an object of the present invention to provide a sputtering apparatus which solves the problem of uneven wear between an edge portion and a center portion of a rectangular target.

[0011]

SUMMARY OF THE INVENTION In view of the above problems, a sputtering apparatus according to the present invention has a vacuum vessel provided with an exhaust system for evacuating the inside thereof, and a substrate which is located in the vacuum vessel and is subjected to film formation processing. , A magnetron cathode electrode provided with a rectangular planar target for forming a film on the surface of the substrate, a gas control system for flowing gas through a vacuum vessel to appropriately maintain the internal pressure, and a magnetron cathode And a power supply system for supplying power to the electrodes, wherein the magnetron cathode electrode includes a plurality of first and second types of magnet units in which the arrangement relationship of the magnetic poles is opposite to each other and is alternately adjacent to each other, and A plurality of magnet units each including a magnet assembly having different side lengths of the plurality of magnet units and a moving mechanism for reciprocating the magnet assembly along a target; Each make electron drift motion trajectory of rectangular ring based on electronic restraining action of the electromagnetic field on the surface of the target, constructed as short side portions of the plurality of electron drift motion trajectories do not overlap each other. In the above configuration, preferably, the plurality of magnet units have the same short side length and the long side portions have different lengths. The magnetron cathode electrode has the same basic configuration as the above-described sputtering apparatus, and further, the magnetron cathode electrode is formed by alternately adjoining two types of first and second types of magnet units having the same dimensions and opposite arrangement relations of the magnetic poles. A magnet assembly in which a plurality of magnet units are arranged and center positions of the plurality of magnet units are different from each other in a direction orthogonal to the moving direction; and a moving mechanism for reciprocating the magnet assembly along the target. Each magnet unit forms an annular electron drift motion trajectory of the same shape on the surface of the target based on the electron restraining action of the electromagnetic field, and the center positions of the plurality of annular electron drift motion trajectories are different in a direction orthogonal to the moving direction. It is configured as follows. In each of the above configurations, preferably, the first and second
Each of the magnet units includes a yoke, a center magnet disposed thereon, and a peripheral magnet disposed on the yoke and around the center magnet. A magnetic pole surface is provided on the yoke side and the opposite side.

[0012]

In the sputtering apparatus according to the present invention, as a basic operation, a magnet assembly having a plurality of magnet units is reciprocated in parallel to a target surface by a magnetron cathode electrode having a rectangular flat target. In such a manner, the combination of an electric field and a magnetic field formed by each magnet unit generates a rectangular annular trajectory formed by drift electrons at a position corresponding to each magnet unit on the target surface. As the plurality of magnet units disposed on the magnetron cathode electrode, two types of magnet units having opposite magnetic pole arrangement structures are prepared, and these two types of magnet units are alternately arranged adjacent to each other. . By appropriately selecting the magnetic poles of the plurality of magnet units and appropriately arranging them, a plurality of rectangular annular electron drift motion trajectories can be efficiently arranged on the target surface as a whole of the magnet assembly. The above discharge can be stably maintained without being ubiquitous. In addition, since the magnet assembly has a structure to which a moving mechanism is added, the magnet assembly can be vibrated almost parallel to the surface of the rectangular flat target inside the magnetron cathode electrode, and the region of the target to be etched is reduced. It can be made uniform.

Further, in the sputtering apparatus according to the present invention, the short side portion of the rectangular annular electron drift motion trajectory of each magnet unit is periodically arranged in parallel with the motion direction based on the configuration in which the magnet assembly moves so as to perform reciprocating motion. When moving to, the dimensions and the like of at least the long sides of each magnet unit are changed, the short sides of the electron drift motion trajectory by each magnet unit are set so as to be shifted from each other, and respectively different appropriate positions Is moved periodically.
Thus, the amount of sputter etching in the target region corresponding to the short side of each electron drift motion trajectory is reduced, the amount of sputter etching in the entire target is made uniform, and the utilization efficiency of the entire target is improved.

[0014]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a view showing the overall configuration of a sputtering apparatus according to the present invention. In FIG. 1, in the sputtering apparatus, a substrate tray insertion chamber 1, a sputtering chamber 2 for forming a thin film on a surface of a substrate mounted on the tray, and a substrate tray unloading chamber 3 are connected in series. It consists of. Each of the chambers 1, 2, 3 has an exhaust system independently, and is maintained and managed in a vacuum state. A gate valve 4 is provided between the substrate tray insertion chamber 1 and the sputtering chamber 2, and a gate valve 5 is provided between the sputtering chamber 2 and the substrate tray removal chamber 3. The sputtering chamber 2 is maintained and managed in a vacuum state during film formation. The substrate tray insertion chamber 1 and the substrate tray unloading chamber 3 are opened to the atmosphere by leak valves 6 and 7, respectively, or are exhausted by exhaust pumps (not shown) via exhaust pipes 8 and 9 as indicated by arrows 10 and 11, respectively. Exhausted in the direction. The left end of the substrate tray insertion chamber 1 in the figure is an entrance door 12.
The right end of the substrate tray unloading chamber 3 in the figure is an exit door 13.
It is.

The tray 14 on which the substrates are mounted is stored in the substrate tray insertion chamber 1 from the entrance door 12. Tray 14
Is a means for holding the substrate. This substrate has a large diameter and is relatively large. Then, the entrance door 12
With the gate valve 4 closed, exhaust is performed using the exhaust system. When the internal pressure of the substrate tray insertion chamber 1 has sufficiently decreased, the gate valve 4 is opened, and the tray 14 is guided by a rail (not shown), transported in the direction of arrow 15, and sent into the sputtering chamber 2.

In the sputtering chamber 2, a thin film is formed by a sputtering method on a surface of the substrate mounted on the tray 14 and in a stationary state by a thin film manufacturing mechanism described later. After the thin film is formed, the tray 14 is moved to the substrate tray unloading chamber 3 via the opened gate valve 5.
Sent to. After the tray 14 is transferred to the substrate tray unloading chamber 3, the gate valve 5 is closed and the leak valve 7 is opened, and the substrate mounted on the tray 14 is placed in the atmosphere. Then, the take-out door 13 is opened, and the tray 14 is taken out. In the sputtering chamber 2, a gas is introduced from a cylinder (not shown) through a gas introduction pipe 16 in the direction of an arrow 18 a, and is similarly exhausted by an exhaust pump (not shown) through an exhaust port 17 in a direction of an arrow 18 b. As a result, the sputtering chamber 2 is maintained in a discharge state while the flow rate of the introduced gas and the flow rate of the exhaust gas are balanced, and a predetermined constant pressure in a range of 10 ^-3 to 10 ^-2 Torr suitable for performing sputtering. Is kept. A substrate heating lamp 19 is provided on the entrance side in the sputtering chamber 2. The substrate heating lamp 19 is provided as needed. By the heat ray radiation of the substrate heating lamp 19, the temperature of the substrate can be increased before the thin film is formed.
A magnetron cathode electrode 20 (hereinafter, referred to as an electrode 20) including a large target having a rectangular planar shape is provided via an insulator 21 on the rear side of the sputtering chamber 2. A target assembly 22 is mounted on the upper part of the electrode 20. In FIG. 1, the upper surface of the target assembly 22 is the target surface. The electrode 20 has a power source 24.
And a power supply system 23 including a power supply line 25 between the electrode power supply and a connection 26 between the power supply grounds, and power is supplied by this configuration.

In the sputtering chamber 2, the tray 14 is stationary with respect to the electrode 20, and the substrate on the tray 14 faces the target surface of the target assembly 22 in this state. Sputtered particles flying from the target assembly 22 are deposited on the opposing surface of the substrate, and a thin film is formed on the substrate. In the example in FIG. 1, a combination of one tray 14 and one electrode 20 is shown, but any number of electrodes 20 in the sputtering chamber 2 can be provided. The wall of the sputtering chamber 2 is grounded.

Next, referring to FIG. 2 and FIG.
The structure of the first embodiment will be specifically described in detail. FIG. 2 shows the electrode 2
FIG. 3 is a cross-sectional view taken along a direction parallel to the direction of movement, and FIG. 3 is a plan view of the magnet assembly. In FIG.
The dimension of the magnet assembly in the long side direction is reduced. Electrode 2
Reference numeral 0 denotes an electrode housing 31, a magnet assembly 32 movably provided to reciprocate inside the electrode housing 31, and the target assembly 22. In FIG. 2, the illustration of the moving mechanism for reciprocating the magnet assembly 32 is omitted. Reference numeral 33 denotes a part of the wall of the container forming the sputtering chamber 2. The electrode 20 is attached to the opening 34 formed in the wall 33 via the insulator 21. The electrode 20 is attached to the opening 34 such that the target surface of the target assembly 22 is exposed to the vacuum chamber. Fixtures, clamp mechanisms, and the like for attachment are not shown. The target assembly 22 includes a target plate 35, a target holding jig 36, and a target back plate 37, and is fixed to the electrode housing 31 by a coupling (not shown). Electrode housing 3
The above-described magnet assembly 32 is movably installed in the concave space 38 formed in the inside of the unit 1. Specifically, in the concave space 38, for example, three magnet units 44 including a center magnet 41, a peripheral magnet 42, and a yoke 43 are provided. 3
As shown in FIG. 3, the magnet units are arranged such that the short sides A have the same length and the long sides B have different lengths in the planar shape. Therefore, the distance from the line L, which is formed by connecting the center positions of the respective magnet units and is parallel to the movement direction, to the short side (that is, the length of the long side).
Is different for each magnet unit. More precisely, the magnet unit 44 has two types of magnet units (4) having different directions of movement of the generated electron drift movement trajectory.
4A, 44B). Details of the magnet unit will be described later. A shunt spacer 45 is provided between each magnet unit 44. Thus, the magnet assembly 32 includes three magnet units 44 and two shunt spacers 45. This shunt spacer
It is not always necessary. Although not shown, cooling water is introduced and discharged from the outside of the electrode housing 31 into the concave space 38 so that the cooling water is brought into contact with the target back plate 37 to discharge the cooling water onto the target surface of the target assembly 22 when performing discharge. The generated heat is released outside using cooling water as a medium. An O-ring 39 is provided between the electrode housing 31 and the target back plate 37 to maintain airtightness. The O-ring 40 maintains the airtightness between the electrode 31 and the insulator 21, and the O-ring 47 maintains the airtightness between the insulator 21 and the wall 33 of the vacuum vessel. It is not desirable that the surface of the target assembly 20 exposed to the vacuum side other than the surface to be sputtered is subjected to ion bombardment.
3 is disposed in a peripheral portion of the opening portion 34 on the inner surface of the third.

The magnet assembly 32 including the three magnet units 44 having the above-described configuration performs a reciprocating motion 100 in the concave space 38 as shown in FIG. As a result, a uniform thin film can be formed on the substrate 14 that is stationary in the sputtering chamber 2 so as to face the target plate 35. Since the short sides of each magnet unit have different distances from the center line L and are located at different positions, the surface of the target plate 35 can be sputter-etched over a wide range and uniformly. The target region corresponding to the short side and the target region corresponding to the long side are relatively uniformly sputtered.

In the above embodiment, the magnet assembly 32 includes three magnet units 44 as one set. However, the number of the magnet units 44 is not limited to three, and is arbitrary. Also, the number of sets can be plural.

FIG. 4 shows a second embodiment. In the second embodiment, similarly to the first embodiment, the length of the long side of each magnet unit 44 is made different, and the length of the short side is also made different. According to this embodiment ,
In comparison, the total width of the three magnet units is reduced.
Therefore, the moving position of the magnet assembly 32 can be configured to be closer to the inner surface of the concave space 38 of the electrode housing 31 than the setting position of the target holding jig 36. Thereby, each magnet unit 44 of the magnet assembly 32 can pass through most of the surface of the target plate 35, and more uniform sputter etching can be performed.

Next, referring to FIGS.
2 will be described.
FIGS. 5 and 9 are cross-sectional views, FIGS. 6 and 10 are plan views, FIGS. 7 and 11 are perspective views, and FIGS. 8 and 12 are views showing a locus of electron drift motion in a rectangular ring.

The magnet unit 44 is composed of a long plate-shaped center magnet 41 and a rectangular ring-shaped peripheral magnet 42 disposed around the center magnet 41 on the upper surface of a yoke 43 having a rectangular shape in plan view. The magnet unit shown in FIGS. 5 to 8 is the above-described magnet unit 44A. In the magnet unit 44A, the magnetic pole on the yoke side of the center magnet 41 is the S pole and the opposite side is the N pole, and the magnetic pole on the yoke side of the peripheral magnet 42 is the N pole.
The pole and the opposite side are arranged to be S poles. As a result, magnetic lines of force indicated by arrows 45 extending from the center magnet 41 to the peripheral magnet 42 are formed. In FIGS. 5 to 8, the lines of magnetic force are shown by a finite number, but are actually infinite. In the electrode portion provided with the magnet unit 44A having the above configuration, the lines of magnetic force exiting from the center on the target surface and entering the periphery,
Form a closed tunnel path with the required width. In this state, when a negative high potential with respect to the ground potential is applied to the electrode, the electrons are closed on the target surface based on the combination of the electric field perpendicular to the target surface and the magnetic field due to the magnetic field lines forming the tunnel path. An annular drift motion is performed along the tunnel path. As a result, a discharge of a low voltage and a large current is generated, and a sputtered film can be manufactured at a high speed. FIG. 8 shows the trajectory of the drift motion of the electrons on the target surface, and the drift motion is performed along the rectangular annular trajectory 46 in the direction indicated by the arrow. Annular locus 4
6 is formed in a belt shape or a road shape. Next, FIGS.
The magnet unit shown in FIG. 2 is a magnet unit 44B, and has basically the same components as the magnet unit shown in FIGS. The difference is that the arrangement of the magnetic poles of the center magnet 41 'and the peripheral magnet 42' is opposite to that described above. As a result, as shown in FIGS. 6 to 8, the direction of the magnetic force line 45 ′ is formed in a direction from the peripheral magnet 42 ′ to the center magnet 41 ′. Therefore, when a high negative potential with respect to the ground potential is applied to the electrode, a drift motion of electrons is formed on the target surface by the action of the combination of the electric field and the magnetic field as described above.
As shown in FIG. 5, the circular trajectory is formed in the opposite direction to the above case, and the electrons drift along this circular trajectory 46 '.

In FIGS. 8 and 12, a short side portion a and a long side portion b are defined by the rectangular annular electron drift motion trajectories 46 and 46 '. The short side a corresponds to the short side A of the magnet unit 44, and the long side b corresponds to the long side B of the magnet unit 44.

In the configuration of the embodiment described with reference to FIGS. 2 and 3, out of the three magnet units, the magnet units on both sides are 44A, and the center magnet unit is 44B.
Therefore, each magnet unit 4 of the magnet assembly 32 of the first embodiment is
4 formed by the electron drift motion trajectory shown in FIG.
Is generated as shown in In FIG. 13, the electron drift motion trajectories 46 and 46 'have the same shape as a rectangular ring. The length of the short side a is also the same. But,
The distances (the lengths of the long sides) from the center line L formed by connecting the center positions of the annular motion trajectories to the short sides are different from each other. As a result, the short sides of the electron drift trajectories are shifted from each other, so that in the reciprocating motion, target regions having different short sides are sputter-etched, and the utilization efficiency of the target plate 35 is improved. In FIG. 13, reference numeral 101 denotes an outline representing the area of the concave space 38, and reference numeral 100 denotes a reciprocating motion.

As described above, with respect to the plurality of magnet units constituting the magnet assembly, by making the lengths of the long sides of the rectangular magnet unit composed of the center magnetic pole and the peripheral magnetic poles different from each other, each short side and the center are changed. The distance from the line L is made different. Thereby, with respect to the rectangular annular electron drift motion trajectory generated by each magnet unit, the moving position on the target of each short side that moves periodically in parallel with the reciprocating motion direction is shifted, and sputter etching is performed at each short side. Since the target regions are configured to avoid overlapping each other, the utilization efficiency of the target material is improved.

Next, another embodiment of the electron drift trajectory will be described with reference to FIG. FIG. 15A shows the electron drift motion trajectories 46 and 46 'formed by the configuration based on the second embodiment described above. In these motion trajectories, the length of the long side portion and the length of the short side portion are different from each other. In a configuration in which a magnet assembly 32 in which three magnet units are arranged is reciprocated, a magnet assembly 32 shown in FIG.
It is also possible to have a configuration as shown in FIGS. 5 (C) and (D). In the embodiment of FIG.
The lengths of the short side and the long side of each of the motion trajectories (a), (b) and (c) are made different, and the intervals between them are widened. In the embodiment of FIG. 15D, the positions of the motion trajectories (a), (b), and (c) in the embodiment of FIG. 15C are replaced, and the motion directions of the motion trajectories (b) and (c) are changed. It is configured to be inverted. That is, while maintaining the combination of the movement directions of the electron drift movement trajectories, the lengths and widths of the short sides and the long sides of each movement trajectory are different, and the arrangement method is arranged in order as in the above embodiment. Instead of arranging them, they are arranged in any order. As described above, by changing the length of the short side and the long side of each magnet unit, the utilization efficiency of the target can be further increased.

FIG. 15B shows that six electron drift motion trajectories 46 and 46 'are arranged alternately and their center point 1
02 are alternately arranged in a direction orthogonal to the moving direction. The shape itself of each rectangular electron drift motion trajectory has the same dimensions. Also in this case, adjacent
Since the positions of the moving trajectories of the electron drift motion are not the same , the same effect as in the above case is produced.

As described above, various dimensions and arrangements can be considered for the electron drift motion trajectory. A magnet unit is provided corresponding to each of these electron drift motion trajectories.

Here, the cross section of the target plate 35 after sputter etching corresponding to each of the electron drift motion trajectories (a), (b) and (c) shown in FIG. a), (b) and (c). In this case, the electron drift motion trajectories (a), (b), (c)
Indicate that the sputter etching is performed in a state where they are stopped for a predetermined time, and the cross section shown in FIG. 14 is a cross section cut in parallel to the short side. Similarly, FIG.
The aforementioned electron drift motion trajectory (a) shown in (C),
Target plates 35 corresponding to each of (b) and (c)
FIG. 16 shows a sputter-etched region on the surface of the substrate. Each electron drift motion trajectory (a), (b), (c)
Have different widths as shown in FIG. 16, the sputter etching amount on the target is determined according to the width as shown in FIG. Sputter etching amount in motion trajectory (a) is a hatched portion S _1,
In the locus of motion (b), the amount of sputter etching is the shaded area S ₂
, And the sputter etching amount in motion trajectory (c) is a hatched portion S _3. Accordingly, if the electron drift motion trajectories (a), (b), and (c) move on the target surface, the sputtering becomes more uniform than when each trajectory is stationary.
An etched shape is obtained. It is shown by a solid line in FIG.
Reciprocate the electron drift trajectory at almost the same speed as described later
When it is moved, its etched shape is indicated by the broken line in FIG.
It will be uniform as shown. FIG. 16 is a diagram of the electron drift orbit region of FIG. 14 as viewed from above the target surface.

Next, another embodiment of the magnetron cathode electrode according to the present invention will be described with reference to FIGS. In this electrode, the configurations and relative positional relationships of an electrode housing, a target assembly, a wall of a sputtering chamber and its opening, a plurality of O-rings for maintaining airtightness, a shield member, and the like are based on FIG. This is the same as the case of the electrode of the above-described embodiment. Therefore, the same components are denoted by the same reference numerals, and description thereof will be omitted. The feature of this embodiment lies in the configuration of the magnet assembly. Hereinafter, the configuration of the magnet assembly will be described.

The magnet assembly 51 includes four magnet units 4
4 and more specifically, the magnet unit 44A
And the magnet unit 44B are arranged alternately. A shunt spacer 45 is provided between the magnet units. In the magnet assembly 51 of the present embodiment, since the number of the magnet units 44 is four, the concave space 3 inside the electrode housing 31 is used.
8, a space 52 having a width substantially equal to the width of one magnet unit remains. Therefore, in the concave space 38 in the electrode housing 31, the magnet assembly 51 is
Alternatively, it is possible to reciprocate in the direction of arrow 54. With the reciprocation of the magnet assembly 51, its amplitude is approximately equal to the width of one magnet unit. The magnet assembly 51 of this embodiment is provided with a moving mechanism for moving the magnet assembly.

The moving mechanism will be described with reference to FIGS . 17, 19 and 20. FIG. 20 shows KK in FIG.
It is a line sectional view. Reference numeral 55 denotes a support for supporting the magnet assembly 51. The magnet assembly 51 is fixed to the support 55 with screws or the like (not shown). Further, the support 55 is provided with a driving plate 56.
Fixed to The drive plate 56 has, for example, a rectangular guide hole 5.
7 is formed at the center, and a circular cam 58, for example, which is in contact with a part of the inner wall of the guide hole 57 is arranged in the guide hole 57. The cam 58 is rotated by a cam shaft 59. Drive plate 5
For example, four slide bearings 60 are fixedly provided at the bottom of the base 6. Further, for example, two guide bars 61 are disposed in the longitudinal direction near the bottom of the concave space 38, and the slide bearing 60 is inserted through the guide bar 61. Both ends of each guide bar 61 are connected to the electrode housing 31.
Is fixed by a receiving cylinder 62 provided on the inner wall surface of the concave space 38. With such a configuration, the drive plate 56 is
And is movable in the direction of arrow 53 or arrow 54. When the camshaft 59 rotates, the cam 5
The drive plate 56 reciprocates in the concave space 38 according to the contact relationship between the guide hole 8 and the guide hole 57. Cam 58 and guide hole 5
7 is circular and the rotational speed of the camshaft 59 is constant, the speed of the reciprocating motion of the drive plate 56 is low at both ends,
The movement becomes a fast simple vibration at the center. The aforementioned guide hole 57
Is not limited to a rectangular shape, and may be an elliptical shape or an arbitrary shape similar thereto as long as the driving plate 56 can reciprocate by rotating the cam 58. The camshaft 59 is connected to an output shaft of the motor 63 and is rotated by the motor 63. Motor 63
Is disposed outside the electrode housing 31 and is fixed to the electrode housing 31 by the support frame 64 and the support base 65. The camshaft 59 is fixed by a bearing cylinder 68 in which a radial bearing 66 for supporting the camshaft while rotating smoothly and an oil seal 67 for sealing the cooling water in the electrode housing while rotating are fitted. I have. Further, the rotation speed of the cam shaft 59 is
It is also possible to have a velocity distribution with. Suitable rotation speed
By setting the degree distribution, the reciprocating motion of the drive plate 56
Rather than a simple oscillatory motion that is slow at both ends and fast in the center,
The movement can be made to be almost constant speed even in the position.

With the above configuration, when the cam shaft 59 rotates in a fixed direction by the rotation of the motor 63, the magnet assembly 51 reciprocates inside the concave space 38 of the electrode housing 31. FIG. 18 shows an annular trajectory of drift motion electrons formed on the target surface when the magnet assembly 51 is at the left end. The annular trajectories are alternately opposite in directions corresponding to the magnet units 44A and 44B described above. In this state of the annular trajectory, the annular trajectory moves in the direction of arrow 53 as the magnet assembly 51 moves. FIG. 19 shows an annular trajectory of drift motion electrons formed on the target surface when the magnet assembly 51 is at the right end. In this state of the annular trajectory, the annular trajectory moves in the direction of arrow 54 as the magnet assembly 51 moves. Thus, the four annular trajectories correspond to the magnet assembly 51.
It moves with the movement of. Since the directions of the adjacent annular trajectories are opposite, the movement directions of the electrons in the two adjacent path portions in the two adjacent annular trajectories are the same.

In the magnet assembly 51, the magnet units are arranged so that the electron drift motion trajectory shown in FIG. 15B is basically formed. That is,
The magnet units are alternately arranged in a direction orthogonal to the moving direction.

According to the above configuration, the annular trajectory of the plurality of drift motion electrons periodically moves on the target surface, so that the target is uniformly consumed except for both ends, and
This further increases the efficiency of target utilization. In particular, by making the amplitude of the reciprocating motion of the entire magnet assembly equal to the width of the magnet unit, the average film forming rate can be increased while improving the film thickness distribution in the substrate and the target utilization efficiency. Of the film quality can be improved.

The form, size, material, number and the like of each component of each embodiment described above are the most desirable, but are not limited thereto. The magnet material of the center magnet and the peripheral magnet constituting each magnet unit is exactly the same. However, in order to achieve the target utilization efficiency and the uniformity of the film thickness distribution on the substrate, it is sometimes desirable to make the materials and the like of the respective magnet units different for the entire magnet assembly. In such a case as well, a configuration is adopted in which the magnetic poles of the magnet unit having the opposite combination are arranged alternately close to each other.

Regarding the magnets provided in the magnet unit, for example, as shown in FIG. 21 (A) or (B), when arranged in the electrode housing 31, the respective magnetic pole surfaces 71a, 71b, 71 'of the magnets 71, 71'. a, 71'b can be configured to be perpendicular to the target plane.
In this case, it is not necessary to provide the center magnet described above.
FIG. 22 shows a magnet unit 71 using the magnet of FIG.
The five magnets 71 ′ are arranged on the support plate 72 and
An example in which is formed. In this configuration example, it is not necessary to provide a shunt spacer for suppressing mutual interference between adjacent magnetic poles. Therefore, it is possible to extremely efficiently dispose it in the electrode housing, and to achieve further miniaturization.

In the magnetron cathode electrode, the width of the target-shaped annular band subjected to sputter etching is increased,
To improve target utilization, a pole assembly having a more complex structure can be used. Also in this case, the configuration of the present invention can be adopted. FIG.
In the moving mechanism of the magnet assembly of the embodiment described with reference to FIG. 20, the mechanism of the horizontal reciprocating motion by the cam and the guide hole has been described, but any of these moving mechanisms may be adopted. Can be.

[0040]

As is apparent from the above description, according to the present invention, in a sputtering apparatus, a magnet assembly including a plurality of magnet units is provided on a magnetron cathode electrode having a large target having a rectangular planar shape; For these plural magnet units, two types of magnet units having the opposite arrangement of the magnetic poles are prepared, and these are arranged alternately adjacent to each other, or a moving mechanism is added to the electrodes. Since the magnet assembly is configured to be caused to vibrate, a film forming process can be performed on a rectangular substrate having a large area, and the sputtering apparatus can be formed small. In particular, by changing the length of at least the long side of the electron drift motion trajectory formed corresponding to the form of the magnet unit, or shifting the center position of each magnet unit in the long side direction, each electron parallel to the moving direction The position of the short side portion of the drift motion trajectory is shifted, the sputter etching amount due to the short side portion which increases due to the overlap of the short side portions is relatively reduced, and the sputter etching amount on the target is made uniform overall. In this way, the positions of the short sides of the plurality of magnet units are dispersed, and the ubiquity of the target region to be sputtered is reduced, thereby improving the uniformity of the thickness and quality of the thin film formed on the substrate. In addition, there is an effect that particles generated due to the deposited film on the target surface are suppressed as much as possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a sputtering apparatus according to the present invention.

FIG. 2 shows a first example of a magnetron cathode electrode according to the present invention.
It is sectional drawing which shows an Example.

FIG. 3 is a plan view of the magnet assembly.

FIG. 4 shows a second example of the magnetron cathode electrode according to the present invention.
It is sectional drawing which shows an Example.

FIG. 5 is a sectional view for explaining a first magnet unit.

FIG. 6 is a plan view for explaining a first magnet unit.

FIG. 7 is an external perspective view illustrating a first magnet unit.

FIG. 8 is an explanatory diagram showing an annular trajectory on a target surface by a first magnet unit.

FIG. 9 is a cross-sectional view illustrating a second magnet unit.

FIG. 10 is a plan view for explaining a second magnet unit.

FIG. 11 is an external perspective view for explaining a second magnet unit.

FIG. 12 is an explanatory diagram showing an annular trajectory on a target surface by a second magnet unit.

FIG. 13 is an explanatory diagram showing an annular trajectory on a target surface by the magnetron cathode electrode according to the first embodiment.

FIG. 14 is a cross-sectional view showing a sputter etching amount distribution in a case where the trajectory widths of the electron drift motion trajectories are different.

FIG. 15 is a diagram showing various combinations of electron drift motion trajectories.

FIG. 16 is a diagram showing a sputtering region on a target surface according to the electron drift motion locus of FIG. 15C.

FIG. 17 is a sectional view showing another embodiment of the magnetron cathode electrode according to the present invention.

FIG. 18 is an explanatory diagram showing a first state of an annular trajectory on a target surface by a magnetron cathode electrode according to another embodiment.

FIG. 19 is an explanatory diagram showing a second state of an annular trajectory on a target surface by a magnetron cathode electrode according to another embodiment.

20 is a sectional view taken along the line KK in FIG.

FIG. 21 is an external perspective view showing another embodiment of the magnet provided in the magnet unit.

FIG. 22 is a sectional view illustrating an example of a magnet assembly configured using the magnet illustrated in FIG. 21;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate tray insertion chamber 2 Sputtering chamber 3 Substrate tray removal chamber 14 Tray 20 and 51 Magnetron cathode electrode 22 Target assembly 23 Power supply system 31 Electrode housing 32 Magnet assembly 33 Wall 38 Concave space 41 Center magnet 42 Peripheral magnet 43 Yoke 44 Magnet unit 45 Shunt spacer 46, 46 'Rectangular annular electron drift locus 56 Driving plate 57 Guide hole 58 Cam 63 Motor 71, 71' Magnet 73 Magnet assembly

Claims (4)

(57) [Claims] 1. A vacuum vessel provided with an exhaust system for evacuating the inside, a substrate holding member which is located in the vacuum vessel and has a substrate on which a film is to be formed, and a rectangle which forms a film on the substrate. In a sputtering apparatus including a magnetron cathode electrode having a planar target, a gas control system for appropriately maintaining an internal pressure by flowing a gas through the vacuum vessel, and a power supply system for supplying power to the magnetron cathode electrode, The magnetron cathode electrode is configured such that a plurality of first and second types of magnet units in which the arrangement relationship of the magnetic poles is opposite to each other are alternately arranged adjacent to each other, and the lengths of the side portions of the plurality of magnet units are different from each other. And a moving mechanism for reciprocating the magnet assembly along the target, wherein each of the plurality of magnet units is Make electron drift motion trajectory of rectangular ring based on electronic restraining action of the electromagnetic field in Tsu bets on the surface, the sputtering apparatus being different from the dimensions of the plurality of electron drift motion trajectories each other. 2. The sputtering apparatus according to claim 1, wherein the plurality of magnet units have the same length on the short side and the length on the long side is different. 3. A vacuum vessel provided with an exhaust system for evacuating the inside, a substrate holding member which is located in the vacuum vessel and has a substrate on which a film is formed, and a rectangle which forms a film on the substrate. In a sputtering apparatus including a magnetron cathode electrode having a planar target, a gas control system for appropriately maintaining an internal pressure by flowing a gas through the vacuum vessel, and a power supply system for supplying power to the magnetron cathode electrode, The magnetron cathode electrode is configured such that a plurality of first and second types of magnet units having the same size and opposite arrangement of magnetic poles are alternately arranged adjacent to each other, and the center position of each magnet unit is set in the moving direction. A plurality of magnet units, comprising: a magnet assembly that is different in a direction orthogonal to the magnet; and a moving mechanism that reciprocates the magnet assembly along the target. Each of them produces an annular electron drift motion trajectory of the same shape on the surface of the target based on the electron restraining action of the electromagnetic field, and the center positions of the plurality of annular electron drift motion trajectories are perpendicular to the moving direction. A sputtering apparatus characterized by being different. 4. The sputtering apparatus according to claim 1, wherein each of the first and second magnet units includes a yoke, a center magnet disposed thereon, and the yoke. And a peripheral magnet disposed around the central magnet, wherein the central magnet and the peripheral magnet are provided with magnetic pole surfaces on the yoke side and on the opposite side thereof. Sputtering equipment.