JP2008069402A - Sputtering apparatus and sputtering method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sputtering apparatus improved in film quality by preventing the occurrence of abnormal electrical discharge caused by accumulation of insulators on a target surface. <P>SOLUTION: The sputtering apparatus is equipped with: a vacuum container 11 in which a film-forming process area 20A and a reaction process area 60A are formed; a sputtering means 20 which carries out sputtering in the film-forming process area 20A to deposit a film material substance on the surface of a substrate S; and a plasma generating means 60 which generates a plasma in the reaction process area 60A to produce a reactant of the film material substance deposited on the surface of the substrate S. The sputtering means 20 is equipped with: a cylindrical target 81 which rotates around a central axis Xa-Xb; a magnetic body unit 88 which forms a leakage magnetic field on the surface of the cylindrical target 81; and a target-rotating motor 93 for rotating the cylindrical target 81 relative to the magnetic body unit 88. Since any non-erosion area is hardly formed on the surface of the target, insulators are hardly accumulated, and the occurrence of abnormal electrical discharge is thereby prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sputtering apparatus and a sputtering method, and more particularly to a sputtering apparatus and a sputtering method for forming a thin film by reactive sputtering.

  As a sputtering device, a film forming process region in which a target is sputtered by a magnetron cathode to form a thin film of a film raw material on the substrate surface, and a film formed on the substrate surface in the film forming process region by generating a reactive gas plasma A reactive sputtering apparatus having a reaction process region for reacting a raw material is known (for example, Patent Document 1).

  As shown in FIG. 9, the sputtering apparatus 101 described in Patent Document 1 includes a film formation process region 120 </ b> A partitioned by a partition wall 125, a film formation process region 140 </ b> A partitioned by a partition wall 145, and a partition wall 165. The partitioned reaction process region 160A and reaction process region 160A are formed at positions separated from each other in the vacuum vessel 111. In the film forming process region 120A, a sputter electrode 121 and a flat target 129 fixed thereto are disposed. Further, a sputtering electrode 141 and a flat target 149 fixed thereto are disposed in the film forming process region 140A. By sputtering the target 129 in the film forming process region 120A and the target 149 in the film forming process region 140A, an ultra-thin metal film (film raw material thin film) is formed on the surface of the substrate. Next, the substrate holder 113 holding the substrate is rotated to move the substrate to the reaction process region 160A, and the metal ultrathin film is converted into the metal oxide ultrathin film by plasma of oxygen gas (reactive gas).

However, in a flat target, since the magnetic field generated by the magnetron electrode is fixed without change, a region that is easily sputtered is generated depending on the position of the target.
More specifically, as shown in FIG. 10, the sputtering electrode 121 includes a yoke 122 disposed on the back side of the target 129, a central magnet 123 a fixed to the surface of the yoke 122, and outer magnets 123 b and 123 c. Has been. The central magnet 123a is arranged with the south pole facing the south pole, and the outer magnets 123b and 123c are arranged with the north pole facing the target 129. Therefore, the middle magnet 123a is located between the outer magnet 123b and the middle magnet 123a. A magnetic field is formed, and a part of the magnetic field forms a leakage magnetic field on the surface of the target 129.

  When a high frequency voltage is applied with the inert gas introduced into the film forming process region 120A, plasma is generated in the film forming process region 120A to ionize the inert gas. The ions collide with the target 129 and emit secondary electrons. The secondary electrons move in a trajectory along the horizontal direction with the surface of the target 129 in the leakage magnetic field, and collide with the inert gas to generate more ions. That is, among the leakage magnetic field generated on the surface of the target 129, many ions are generated in the horizontal direction with respect to the surface of the target 129, and sputtering is performed at a high rate. Low.

  For this reason, the target 129 is easily eroded (eroded) in the magnetic field region in the horizontal direction with respect to the surface of the target 129, and the target 129 is not easily eroded in other regions. As described above, a region that is likely to be eroded (erosion region A) and a region that is not easily eroded (non-erosion region B) are generated due to the difference in the direction of the magnetic field, so that the target utilization rate as a whole decreases. As a result, there is a disadvantage that the cost required for film formation increases.

  Further, in the reactive sputtering apparatus, the reactive gas flowing from the reaction process region 160A into the film forming process region 120A reacts with the target 129, and a reaction product (for example, oxide) with the reactive gas on the surface of the target 129. Is easy to accumulate. In the flat target 129 as in Patent Document 1, the erosion region of the surface of the target 129 is easily sputtered, so even if an insulator is accumulated, it is immediately removed by sputtering, but the non-erosion region is difficult to be sputtered. Insulation is easy to accumulate. When an insulator is accumulated on the surface of the target 129, ions having a positive charge are accumulated therein, and a potential difference is generated between the target 129 and a negative potential. When electric charges continue to accumulate in the insulator and eventually exceed the insulation limit, dielectric breakdown occurs and arc discharge (abnormal discharge) occurs. Due to this abnormal discharge, a lump (particle) of the target material is scattered on the substrate, resulting in a defect in the thin film. Moreover, an arc mark remains on the surface of the target due to the abnormal discharge, and a vicious cycle occurs in which an accumulation of an insulator further occurs around the target to cause abnormal discharge, thereby causing defects in the thin film.

  In general reactive sputtering, a reactive gas is introduced also into the film forming process region 120A, and a reaction product of a film raw material and a reactive gas is generated in the film forming process region 120A. Improvements are also being made. However, since it is necessary to prevent the target 129 and the reactive gas from contacting each other as much as possible in order to prevent the abnormal discharge described above, it is practically difficult to introduce the reactive gas into the film forming process region 120A. Even if it is introduced, the concentration is very low, and the contribution to the improvement of the reactivity is very low.

Furthermore, if the concentration of the reactive gas introduced into the reaction process region 160A is too high, the concentration of the reactive gas mixed into the film forming process regions 120A and 140A increases. For this reason, it is necessary to keep the concentration of the reactive gas introduced into the reaction process region 160A low.
As described above, in the conventional sputtering apparatus, a high concentration reactive gas is introduced into the film forming process regions 120A and 140A and the reaction process region 160A to promote the reaction between the film raw material and the reactive gas. It has been difficult to improve.

By the way, conventionally, in a general sputtering apparatus different from reactive sputtering, a technique for reducing the ratio of a non-erosion region in the entire target by rotating the target is known (for example, Patent Documents 2 to 4 and Non-patent document 1).
Patent Document 2 discloses a magnetron sputtering apparatus including a rotatable cylindrical target and an internal linear magnet assembly.
Patent Document 3 discloses a reactive sputtering apparatus including a cylindrical titanium tube and a cylindrical target including a plurality of magnets arranged inside the titanium tube.
Patent Document 4 discloses a sputtering apparatus including a rotatable tubular target and a magnet assembly disposed therein.

JP-A-11-256327 (Claim 7, paragraphs 0010 to 0034, FIG. 1) JP-A-3-21275 (Claim 33, pages 20, 21, 21, 29 and 30) Japanese Patent Application Laid-Open No. 6-158312 (Claims 1-4, paragraphs 0006-0011, FIGS. 1 and 2) JP-T-2002-529600 (Claims 1-4, paragraphs 0006-0011, FIG. 3) Steven J.M. Nadal et al., “Stratesies for high rate reactive sputtering”, Thin Solid Films, Elsevier Science B. et al. V. 2001, Vol. 392, p. 174-183

As described above, in the sputtering apparatuses disclosed in Patent Documents 2 to 4, the usage rate of the target material can be improved to 80 to 90% by rotating the rotary cylindrical target. Thereby, it is possible to reduce the cost required for forming the thin film.
However, an example using such a rotary target in a reactive sputtering apparatus in which the film forming process region and the reaction process region are separated has not been known.

  An object of the present invention is to reduce the cost required for thin film formation by improving the utilization rate of a target in a reactive sputtering apparatus provided at a position where a film forming process region and a reaction process region are separated from each other. It is an object of the present invention to provide a sputtering apparatus and a sputtering method capable of preventing the occurrence of abnormal discharge due to accumulation of reactants and the accompanying deterioration in film quality and shortening the film formation time.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors applied a rotary target to a conventional reactive sputtering apparatus, not only improving the utilization rate of the target, but also on the target surface. The present invention has been completed by obtaining new knowledge that it is possible to prevent the occurrence of abnormal discharge (arc discharge) by preventing the accumulation of reactants.

  That is, according to the sputtering apparatus of the present invention, the above-described problem is a sputtering apparatus for forming a thin film on a substrate, and has a film formation process region and a reaction process region formed in spatially spaced positions from each other. A vacuum container; a substrate transfer means capable of transferring the substrate between the film formation process region and the reaction process region; a sputtering gas introduction means for introducing a sputtering gas into the film formation process region; and the film formation Sputtering means for performing sputtering with the sputtering gas in the process region and attaching a film raw material to the surface of the substrate; reactive gas introducing means for introducing a reactive gas into the reaction process region; and in the reaction process region A plasma that generates plasma and reacts the film source material adhering to the surface of the substrate with the reactive gas. Generating means, and the sputtering means includes a cylindrical target rotatable around a central axis along the longitudinal direction, a magnetic field forming means for forming a magnetic field on the surface of the cylindrical target, and the magnetic field forming means. And a target rotating means for rotating the cylindrical target.

  As described above, since the cylindrical target is rotated with respect to the magnetic field forming means, the surface position of the cylindrical target with respect to the magnetic field is changed, and a non-erosion region is hardly generated. For this reason, it becomes possible to sputter the whole surface of a cylindrical target. In addition, since a non-erosion region is unlikely to occur, it is difficult for an insulator to accumulate on the surface, and it is possible to prevent the occurrence of abnormal discharge. Thereby, it becomes possible to prevent the defect of the thin film from occurring due to the lump of the target material scattered on the substrate.

  In addition, the sputtering unit includes an AC power source that is disposed adjacent to the film formation process region and alternately applies a voltage to the pair of sputtering units disposed adjacent to each other. preferable.

In this way, a pair of sputtering means are disposed adjacent to each other in the film forming process region, and by applying an alternating voltage thereto, positive and negative potentials are alternately applied to the cylindrical target provided in the sputtering means. Applied. For this reason, even if electric charges accumulate on the surface of the cylindrical target, they are neutralized and the occurrence of abnormal discharge is prevented. Thereby, it becomes possible to prevent the defect of the thin film from occurring due to the lump of the target material scattered on the substrate.
In addition, when one of the pair of sputtering means is positive and the other is negative, the discharge in the film forming process area is sustained, and stable without reducing the film forming rate. Thin film formation can be performed.

  The vacuum container has a plurality of film forming process regions, and each of the plurality of film forming process regions is provided with the sputtering means including the cylindrical target, and the plurality of film forming processes. It is preferable that the cylindrical target disposed in one of the regions is formed of a material different from the cylindrical target disposed in any one of the other regions.

  In this way, a composite thin film in which thin films made of different materials are laminated can be formed on the substrate. This makes it possible to provide variations in the physical and optical characteristics of the thin film.

  Furthermore, it is preferable that the film forming process region does not have a partition wall for preventing gas from flowing into the inside.

  Thus, since the film forming process area does not have a partition wall, the configuration of the sputtering apparatus can be simplified. Further, since the reactive gas introduced into the reaction process region easily flows into the film forming process region, the reactivity can be further improved by using the reactive gas introduced into the reaction process region. . Thereby, the cost required for thin film formation can be reduced.

  Further, the above-described problem is a sputtering method for forming a thin film on a substrate according to the sputtering method of the present invention, and a sputtering gas introduction step for introducing a sputtering gas into a film forming process region partitioned in a vacuum vessel; A sputtering process in which a cylindrical target is sputtered by the sputtering gas in the film forming process region to deposit a film raw material on the surface of the substrate, and is formed at a position spatially separated from the film forming process region. A substrate transport step for transporting the substrate to the reaction process region, a reactive gas introduction step for introducing a reactive gas into the reaction process region, and a plasma generated in the reaction process region to adhere to the surface of the substrate And a plasma generating step for reacting the film raw material and the reactive gas, and in the sputtering step, On the surface of the Jo target while a magnetic field is solved by rotating about the axis along the cylindrical target in its longitudinal direction.

  In this way, by rotating the cylindrical target with respect to the magnetic field forming means, the surface position of the cylindrical target with respect to the magnetic field is changed, and the non-erosion region is hardly generated, so that the entire surface of the cylindrical target is sputtered. It becomes possible to do. In addition, since a non-erosion region is unlikely to occur, it is difficult for an insulator to accumulate on the surface, and it is possible to prevent the occurrence of abnormal discharge. Thereby, it becomes possible to prevent the defect of the thin film from occurring due to the lump of the target material scattered on the substrate.

  According to the sputtering apparatus and the sputtering method of the present invention, since the cylindrical target is rotated with respect to the magnetic field forming means, a non-erosion region is hardly generated, and the entire surface of the cylindrical target can be sputtered. . In addition, since a non-erosion region is unlikely to occur, it is difficult for an insulator to accumulate on the surface thereof, so that abnormal discharge can be prevented and defects in the thin film can be prevented. For this reason, it becomes possible to manufacture a thin film with excellent film quality at a low cost.

  An embodiment of the present invention will be described below with reference to the drawings. It should be noted that the members, arrangements, and the like described below are examples embodying the present invention and do not limit the present invention, and it goes without saying that various modifications can be made in accordance with the spirit of the present invention.

  1 to 6 are diagrams for explaining a sputtering apparatus according to an embodiment of the present invention. FIG. 1 is an explanatory view showing a state of the sputtering apparatus as viewed from the upper side, and FIG. FIG. 3 is an explanatory view showing the state of the sputtering apparatus as viewed from the side, taken from the side, FIG. 3 is an explanatory view showing the periphery of the film forming process area of the sputtering apparatus of FIG. 1, and FIG. 4 is a perspective view of the rotating cathode unit. 5 is an Xa-Xb cross-sectional view of the rotating cathode unit of FIG. 4, and FIG. 6 is an explanatory diagram showing an enlarged view of the reaction process region periphery of the sputtering apparatus of FIG.

In the sputtering apparatus 1 of the present embodiment, a sputtering process in which a thin film considerably thinner than the target film thickness is adhered to the surface of the substrate S, and a reaction process in which the thin film is subjected to plasma treatment to convert the composition of the thin film. By forming the intermediate thin film on the surface of the substrate S and repeating the sputtering process and the reaction process a plurality of times, a plurality of intermediate thin films are stacked to form a final thin film having the desired film thickness on the surface of the substrate S. Yes.
Specifically, the step of forming an intermediate thin film having an average film thickness after composition conversion of about 0.01 to 1.5 nm on the surface of the substrate S by the sputtering step and the reaction step is performed each time the rotary drum 13 rotates. By repeating, a final thin film having a target film thickness of several nm to several hundred nm is formed.

Hereinafter, the sputtering apparatus will be described.
As shown in FIG. 1, the sputtering apparatus 1 of this embodiment includes a vacuum vessel 11, a rotating drum 13, a drum rotating motor 17 (see FIG. 2), a sputtering unit 20, a sputtering gas supply unit 30, and a plasma. The generation means 60 and the reactive gas supply means 70 are main components.
In the figure, the sputtering means 20 and the plasma generation means 60 are indicated by broken lines, and the sputtering gas supply means 30 and the reactive gas supply means 70 are indicated by a one-dot chain line.
In this embodiment, an example in which silicon oxide (SiO ₂ ) is formed will be described.

  The vacuum container 11 is a hollow body made of stainless steel, which is usually used in a known sputtering apparatus, and has a substantially rectangular parallelepiped shape. The inside of the vacuum vessel 11 is divided into a thin film forming chamber 11A and a load lock chamber 11B by a door 11C as an open / close door. A door storage chamber (not shown) for storing the door 11C is connected above the vacuum vessel 11, and the door 11C opens and closes by sliding between the inside of the vacuum vessel 11 and the inside of the door storage chamber. .

The vacuum vessel 11 is provided with a door 11D for partitioning the load lock chamber 11B and the outside of the vacuum vessel 11. The door 11D opens and closes by sliding or rotating. An exhaust pipe 16a-1 is connected to the thin film forming chamber 11A, and a vacuum pump 15a for exhausting the inside of the vacuum vessel 11 is connected to the pipe 16a-1. An opening is formed in the pipe 16a-1 inside the vacuum vessel 11, and this opening is located between the film forming process region 20A and the reaction process region 60A inside the vacuum vessel 11. As a result, the film raw material scattered in the film forming process region 20A can be sucked by the vacuum pump 15a, and the film raw material scattered from the film forming process region 20A enters the reaction process region 60A and enters the plasma generating means 60. Or contaminated by adhering to the surface of the substrate S located outside the film forming process region 20A.
Further, an exhaust pipe 16b is connected to the load lock chamber 11B, and a vacuum pump 15b for exhausting the inside of the vacuum vessel 11 is connected to the pipe 16b.

Since the sputtering apparatus 1 of this embodiment includes the load lock chamber 11B, the substrate S can be loaded and unloaded while maintaining the vacuum state in the thin film forming chamber 11A. Therefore, every time the substrate S is carried out, it is possible to save the trouble of degassing the inside of the vacuum vessel 11 to make a vacuum state, and the film forming process can be performed with high work efficiency.
In addition, although the vacuum vessel 11 of this embodiment employ | adopts the load lock system provided with the load lock chamber 11B, it is also possible to employ | adopt the single chamber system which does not provide the load lock chamber 11B. It is also possible to employ a multi-chamber system that includes a plurality of vacuum chambers and can form a thin film independently in each vacuum chamber.

The rotating drum 13 is a cylindrical member for holding the substrate S on the surface of which a thin film is to be formed, inside the vacuum vessel 11, and has a function as a substrate holding means. As shown in FIG. 2, the rotating drum 13 includes a plurality of substrate holding plates 13a, a frame 13b, and a fastener 13c for fastening the substrate holding plate 13a and the frame 13b as main components. The rotating drum 13 corresponds to the substrate transport means of the present invention.
The substrate holding plate 13a is a flat plate member made of stainless steel, and is provided with a plurality of substrate holding holes for holding the substrate S in a row at the center of the plate surface along the longitudinal direction of the substrate holding plate 13a. The board | substrate S is accommodated in the board | substrate holding hole of the board | substrate holding plate 13a, and is being fixed to the board | substrate holding plate 13a using the screw member etc. so that it may not drop | omit. In addition, screw holes through which fasteners 13c, which will be described later, can be inserted are provided on the plate surfaces at both ends in the longitudinal direction of the substrate holding plate 13a.

The frame 13b is made of stainless steel, and is composed of two annular members arranged vertically. Each annular member of the frame 13b is provided with a screw hole at a position corresponding to the screw hole of the substrate holding plate 13a. The board holding plate 13a and the frame 13b are fixed using a fastener 13c made of bolts and nuts. Specifically, it is fixed by inserting a bolt into the screw holes of the substrate holding plate 13a and the frame 13b and fixing with a nut.
The rotating drum 13 in the present embodiment has a polygonal column shape with a polygonal cross section because a plurality of flat substrate holding plates 13a are arranged, but is limited to such a polygonal column shape. Instead, it may be cylindrical or conical.

The substrate S corresponds to the base body of the present invention, and is a member formed of a material such as glass. In the present embodiment, a disk-shaped substrate is used as the substrate S, but the shape of the substrate of the present invention is not limited to such a disk-shaped substrate, and other shapes that can form a thin film on the surface, For example, a lens shape, a cylindrical shape, or an annular shape may be used. Here, the glass material is a material formed of silicon oxide (SiO ₂ ), and specifically includes quartz glass, soda-lime glass, borosilicate glass, and the like.

  The material of the substrate is not limited to glass and may be a plastic resin or the like. Examples of the plastic resin include, for example, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, acrylonitrile-butadiene-styrene copolymer, nylon, polybutylene terephthalate, polycarbonate-polyethylene terephthalate copolymer, polycarbonate-polybutylene terephthalate copolymer, Examples thereof include resin materials selected from the group consisting of acrylic, polystyrene, polyethylene, and polypropylene, or mixtures of these materials with glass fibers and / or carbon fibers.

  The rotating drum 13 installed inside the vacuum vessel 11 is configured to be able to move between the thin film forming chamber 11A and the load lock chamber 11B shown in FIG. In this embodiment, a rail (not shown) is installed on the bottom surface of the vacuum vessel 11, and the rotary drum 13 moves along this rail. The rotary drum 13 is disposed inside the vacuum vessel 11 such that the cylindrical axis of rotation Za-Zb (see FIG. 2) is in the vertical direction of the vacuum vessel 11. When the substrate holding plate 13a is attached to or removed from the frame 13b, the rotary drum 13 is transferred to the load lock chamber 11B, and the substrate holding plate 13a is attached to and detached from the frame 13b in the load lock chamber 11B. . On the other hand, during film formation, the rotating drum 13 is transported to the thin film forming chamber 11A and is rotatable in the thin film forming chamber 11A.

  As shown in FIG. 2, the center of the lower surface of the rotary drum 13 is shaped to engage with the upper surface of the motor rotating shaft 17a. The rotating drum 13 and the motor rotating shaft 17a are positioned so that the center axis of the motor rotating shaft 17a and the center axis of the rotating drum 13 coincide with each other, and are connected by engaging both. A surface of the lower surface of the rotary drum 13 that engages with the motor rotation shaft 17a is formed of an insulating member. Thereby, abnormal discharge of the substrate S can be prevented. Further, an airtightness is maintained between the vacuum vessel 11 and the motor rotating shaft 17a by an O-ring.

  The motor rotating shaft 17a rotates by driving the drum rotating motor 17 provided in the lower part of the vacuum vessel 11 in a state where the vacuum state inside the vacuum vessel 11 is maintained. Along with this rotation, the rotating drum 13 connected to the motor rotating shaft 17a rotates around the rotation axis Za-Zb. Since each board | substrate S is hold | maintained on the rotating drum 13, when the rotating drum 13 rotates, it revolves around rotating shaft line Za-Zb as a revolution axis.

  A drum rotating shaft 18 is provided on the upper surface of the rotating drum 13, and the drum rotating shaft 18 is configured to rotate as the rotating drum 13 rotates. A hole is formed in the upper wall surface of the vacuum container 11, and the drum rotation shaft 18 passes through the hole and communicates with the outside of the vacuum container 11. A bearing is provided on the inner surface of the hole so that the rotating drum 13 can be smoothly rotated. In addition, an air-tightness is maintained between the vacuum vessel 11 and the drum rotation shaft 18 by an O-ring.

  Next, the film forming process region 20A and the reaction process region 60A for forming a thin film on the surface of the substrate S will be described. As shown in FIG. 1, a partition wall 12 and a partition wall 14 are erected on the inner wall of the vacuum vessel 11 at a position facing the rotary drum 13. The partition wall 12 and the partition wall 14 are members for partitioning the film formation process region 20A and the reaction process region 60A in the vacuum vessel 11, respectively. The partition wall 12 and the partition wall 14 in this embodiment are both the same stainless steel members as the vacuum vessel 11. Each of the partition wall 12 and the partition wall 14 is configured by a flat plate member arranged one by one on the top, bottom, left, and right, and is in a state of surrounding four sides from the inner wall surface of the vacuum vessel 11 toward the rotary drum 13. Yes. As a result, the film forming process region 20A and the reaction process region 60A are partitioned at positions separated from each other inside the vacuum vessel 11. The end portions of the partition wall 12 and the partition wall 14 are close to the outer peripheral surface of the rotary drum 13, and a slight gap is left between the partition wall 12 and the partition wall 14. This hinders outflow and inflow of gas from the film forming process region 20A and the reaction process region 60A.

  The side wall of the vacuum vessel 11 located in the film forming process region 20A has a convex cross section protruding outward, and a sputtering means 20 is provided on the protruding wall surface. The film forming process region 20 </ b> A is formed in a region surrounded by the inner wall surface of the vacuum vessel 11, the partition wall 12 projecting perpendicularly from the inner wall surface, and the outer peripheral surface of the rotary drum 13. In the film forming process region 20A, a sputtering process for attaching a film raw material to the surface of the substrate S is performed.

  Further, the side wall of the vacuum vessel 11 which is separated from the film forming process region 20A by about 90 ° about the rotation axis of the rotary drum 13 also has a convex cross section projecting outward, and the projecting wall surface has plasma. A generating means 60 is provided. The reaction process region 60 </ b> A is formed in a region surrounded by the inner wall surface of the vacuum vessel 11, the partition wall 14 projecting perpendicularly from the inner wall surface, and the outer peripheral surface of the rotary drum 13. In the reaction process region 60A, the reaction between the film raw material adhering to the surface of the substrate S and the reactive gas is performed.

  When the rotating drum 13 is rotated by the drum rotating motor 17, the substrate S held on the outer peripheral surface of the rotating drum 13 revolves between the position facing the film forming process area 20A and the position facing the reaction process area 60A. Will move repeatedly. As the substrate S revolves in this way, the sputtering process in the film forming process region 20A and the reaction process in the reaction process region 60A are sequentially repeated, and a thin film is formed on the surface of the substrate S. .

(Deposition process area 20A)
Hereinafter, the film forming process region 20A will be described.
As shown in FIG. 3, the sputtering means 20 is installed in the film forming process region 20A.
The sputtering means 20 includes a pair of rotating cathode units 21 and 22 disposed in the film forming process region 20A, a transformer 23 provided outside the vacuum vessel 11 and connected to the rotating cathode units 21 and 22, And an AC power source 24 for supplying power to the rotary cathode units 21 and 22 through the main components.

  Each of the rotating cathode units 21 and 22 is an apparatus for receiving a power supply from the AC power supply 24 to sputter a target and supply a film raw material to the substrate S. The rotary cathode unit 21 and the rotary cathode unit 22 are the same apparatus configured by the same member, and are arranged adjacent to the inner wall surface in the film forming process region 20A.

Hereinafter, members constituting the rotary cathode unit 21 will be described. In the present embodiment, the rotary cathode unit 22 has the same configuration as the rotary cathode unit 21.
As shown in FIG. 4, the rotary cathode unit 21 includes a cylindrical target 81, a box 91 that supports the cylindrical target 81 on an external plane, and a cap 82 that holds the cylindrical target 81 so as not to drop out of the box 91. , 83.

The cylindrical target 81 is formed by forming a film raw material, which is a thin film raw material, into a cylindrical shape, and is a hollow member. In this embodiment, metal silicon (Si) is used as the material of the cylindrical target 81, but other than zinc (Zn), titanium (Ti), copper (Cu), etc., depending on the properties of the target thin film. Any metal may be used. The raw material of the cylindrical target 81 is not limited to a metal, but a metal reaction product such as an oxide such as silicon oxide (SiO _x ) or zinc oxide (ZnO _x ) or a nitride such as silicon nitride (SiN _x ). But you can.

  Both ends of the cylindrical target 81 are crowned by a cap 82 and a cap 83, respectively. The caps 82 and 83 are each composed of a semicircular member with one flat surface open. The caps 82 and 83 are both fixed on a single plane outside the box-shaped box 91 so as to stand in a direction perpendicular to the plane.

  As shown in FIG. 5, a rod-like support bar 84 is provided in the hollow interior of the cylindrical target 81 along the longitudinal direction thereof. Both ends of the support bar 84 are fixed to the inner wall surfaces of the cap 82 and the cap 83, and are positioned so as to coincide with the central axis Xa-Xb along the longitudinal direction of the cylindrical target 81.

  The open ends on both sides of the cylindrical target 81 are closed by a fixed plate 85 and a fixed plate 86, respectively. Each of the fixing plates 85 and 86 is a disk-shaped member having an opening formed at the center thereof, and the support bar 84 passes through the opening. Bearings (not shown) are respectively provided between the opening end faces of the fixing plates 85 and 86 and the outer peripheral surface of the support rod 84, and the fixing plates 85 and 86 are respectively supported by the support rod 84 in a state where the support rod 84 penetrates. It is possible to rotate at the center. A target side gear 89 is fixed to the surface of the fixed plate 85 on the cap 82 side.

  The fixing plate 86 is a member made of a conductive material, and wiring is connected to the surface thereof. An opening is formed in the box 91 in the vicinity of the fixing portion with the cap 83, and the wiring extending from the fixing plate 86 extends into the box 91 through the opening. An opening for leading out the wiring is formed on the wall surface of the box 91 opposite to the side where the cylindrical target 81 is disposed, and the wiring connected to the fixed plate 86 is connected to the box through the opening. 91 extends outside. The wiring extends to the outside of the vacuum vessel 11 and is connected to the AC power source 24 via the transformer 23. Thereby, an alternating voltage is applied from the AC power supply 24 to the cylindrical target 81. In this embodiment, a voltage is applied at a frequency of 10 kHz to 2 MHz.

  A yoke 87 is attached to a portion of the support bar 84 located in the cylindrical target 81. The yoke 87 is a flat plate member, and a magnetic unit 88 is provided on the surface of the yoke 87 opposite to the mounting surface of the support bar 84.

As shown in FIG. 3, the yoke 87 is a flat plate member whose central portion and both end portions protrude in the same direction. A central magnet 88a, which is a permanent magnet, is attached to the tip of the central protruding portion of the yoke 87, and outer magnets 88b, 88c, which are permanent magnets, are attached to the leading ends of the protruding portions on both sides of the yoke 87, respectively. The center magnet 88a is disposed with the south pole facing the substrate S, and the outer magnets 88b and 88c are both disposed with the north pole facing the substrate S. Since they are arranged in this way, magnetic fields are formed between the central magnet 88a and the outer magnet 88b and between the central magnet 88a and the outer magnet 88c. A part of this magnetic field leaks to the surface of the cylindrical target 81, and a leakage magnetic field is formed on the surface of the cylindrical target 81.
The magnetic unit 88 including the central magnet 88a and the outer magnets 88b and 88c corresponds to the magnetic field forming means of the present invention.

In the present embodiment, a permanent magnet is used as the magnet constituting the magnetic body unit 88, but the magnetic field forming means of the present invention is not limited to a permanent magnet, and may be other means for forming a magnetic field, such as an electromagnet. .
Further, the magnetic body unit 88 is disposed inside the cylindrical target 81, but may be at any position as long as a leakage magnetic field can be formed on the surface of the cylindrical target 81. For example, the magnetic body unit 88 may be provided outside the cylindrical target 81.

  As shown in FIG. 5, the box 91 is a box-shaped member having an internal space, and a target rotation motor 93 is provided therein. The target rotation motor 93 is an apparatus that includes an output shaft and rotates the output shaft upon receiving electric power from a DC power source 96. In the present embodiment, the target rotation motor 93 is a DC brushless motor. A motor side gear 94 is fixed to the output shaft of the target rotation motor 93. An intermediate gear 92 meshes with the motor side gear 94. An opening is formed in the box 91 in the vicinity of the fixing portion with the cap 82, and a shaft 95 that supports the intermediate gear 92 is horizontally mounted. A part of the intermediate gear 92 protrudes from the opening to the outside of the box 91 and meshes with the target side gear 89. The target rotation motor 93 is connected to a DC power supply 96 provided inside the box 91 through wiring.

Since the rotary cathode unit 21 has the above-described configuration, the output shaft rotates upon receiving power from the DC power source 96, and this rotation is sequentially transmitted by the motor side gear 94, the intermediate gear 92, and the target side gear 89. Then, the cylindrical target 81 fixed to the target side gear 89 via the fixed plate 85 is rotated. Since the cylindrical target 81 is pivotally supported by the support rod 84 via the fixed plates 85 and 86, the cylindrical target 81 rotates about the support rod 84 as the central axis as the output shaft of the target rotation motor 93 rotates. Since the support bar 84 does not rotate by the rotation of the cylindrical target 81, the magnetic body unit 88 fixed thereto is also configured not to rotate by the rotation of the cylindrical target 81.
It should be noted that only the target rotation motor 93 that rotates the output shaft, the intermediate gear 92 that transmits the rotation of the output shaft, the motor side gear 94 and the target side gear 89, and the cylindrical target 81 without rotating the magnetic body unit 88. The support rod 84 and the fixed plates 85 and 86 to be rotated correspond to the target rotating means of the present invention.

  The target rotating means for rotating the cylindrical target 81 is not limited to such a rotating mechanism using gears, and any mechanism may be used as long as it rotates the cylindrical target. For example, a mechanism may be employed in which pulleys are respectively fixed to the motor output shaft and the cylindrical target, and the pulleys are wound around a belt to transmit the rotation of the motor output shaft to the cylindrical target.

  As shown in FIG. 2, in the film forming process region 20A, the rotary cathode units 21 and 22 both have a longitudinal direction parallel to the longitudinal direction of the rotary drum 13 (that is, the rotation axis Za-Zb direction). Is arranged. Further, as shown in FIG. 3, the rotary cathode units 21 and 22 are fixed to the inner wall surface of the vacuum vessel 11 at the ground potential via the insulating member 26.

A sputtering gas supply means 30 for supplying a sputtering gas such as argon is provided around the film forming process region 20A. The sputtering gas supply means 30 includes a sputtering gas cylinder 32 as a sputtering gas storage means, a mass flow controller 31 as a sputtering gas flow rate adjusting means for adjusting the flow rate of the sputtering gas, pipes 35a and 35c as sputtering gas supply paths, The main components are a reactive gas cylinder 34 as a reactive gas storage means, a mass flow controller 33 as a reactive gas flow rate adjusting means for adjusting the flow rate of the reactive gas, and a pipe 35a and a pipe 35d as reactive gas supply paths. As a component.
Examples of the sputtering gas include inert gases such as argon and helium. In this embodiment, argon gas is used. In this embodiment, oxygen gas is used as the reactive gas.

  The mass flow controller 31, the sputtering gas cylinder 32, the mass flow controller 33, and the reactive gas cylinder 34 are all provided outside the vacuum vessel 11. The mass flow controller 31 is connected to the sputtering gas cylinder 32 via a pipe 35c. The mass flow controller 33 is connected to a reactive gas cylinder 34 via a pipe 35d.

  The mass flow controllers 31 and 33 are respectively connected to the end of the pipe 35a that branches into a Y shape, and the other end of the pipe 35a passes through the side wall of the vacuum vessel 11 and is a rotating cathode unit in the film forming process region 20A. 21 and 22 are extended. As shown in FIG. 2, the tip of the pipe 35 a extends near the lower center of the rotary cathode units 21 and 22, and the tip of the pipe 35 a is bent toward the front center of the rotary cathode units 21 and 22. An opening 35b is formed by opening.

  The mass flow controller 31 is a device for adjusting the flow rate of the sputtering gas, and detects an inlet port for the sputtering gas from the sputtering gas cylinder 32, an outlet port for allowing the sputtering gas to flow into the pipe 35a, and a mass flow rate of the gas. A sensor, a control valve that adjusts the gas flow rate, a sensor that detects the mass flow rate of the gas flowing in from the inlet, and an electronic circuit that controls the control valve based on the flow rate detected by the sensor are the main components. It is provided as a component (both not shown). A desired flow rate can be set to the electronic circuit from the outside. The mass flow controller 33 has the same configuration as the mass flow controller 31. The mass flow controller 33 is a device for adjusting the flow rate of the reactive gas introduced from the reactive gas cylinder 34 into the pipe 35a.

  The sputter gas from the sputter gas cylinder 32 is introduced into the pipe 35 a with the flow rate adjusted by the mass flow controller 31. The reactive gas from the reactive gas cylinder 34 is introduced into the pipe 35a after the flow rate is adjusted by the mass flow controller 33. The sputter gas and the reactive gas flowing into the pipe 35a are mixed and introduced as a mixed gas from the introduction port 35b to the front surfaces of the rotary cathode units 21 and 22 disposed in the film forming process region 20A.

Next, the principle of performing sputtering in the reaction process region 20A will be described.
An alternating voltage is applied from the AC power source 24 to the cylindrical target 81 in a state where the sputtering gas is supplied from the sputtering gas supply means 30 to the film forming process region 20A and the periphery of the rotary cathode unit 21 is in an inert gas atmosphere. Then, a part of the sputtering gas emits electrons and is ionized between the substrate S at the ground potential and the cylindrical target 81. Since a leakage magnetic field is formed on the surface of the cylindrical target 81 by the central magnet 88a and the outer magnets 88b and 88c, electrons circulate in a magnetic field generated near the surface of the cylindrical target 81 while drawing a toroidal curve. . A high-density plasma is generated along the trajectory of the electrons, and ions of the sputtering gas are accelerated toward the plasma and collide with the cylindrical target 81 so that atoms and particles on the surface of the cylindrical target 81 are knocked out. It is. In this embodiment, since the cylindrical target 81 is formed of silicon, silicon atoms and silicon particles are knocked out.

The atoms and particles knocked out of the cylindrical target 81 react with the reactive gas in the plasma and are converted into reactants. In this embodiment, since oxygen gas is introduced as the reactive gas, an incomplete silicon oxide (SiO _x : 0 <x <2) or a complete silicon oxide (SiO ₂ ) is generated. . Silicon incomplete oxide or complete oxide adheres to the surface of the substrate S to form a thin film. Further, unreacted silicon atoms and a part of silicon particles adhering to the surface of the substrate S react with the reactive gas, and are converted into incomplete oxide or complete oxide of silicon.

In this way, a thin film made of silicon, an incomplete oxide of silicon, and a complete oxide is formed on the surface of the substrate S. Silicon, an incomplete oxide of silicon, and a complete oxide attached to the surface of the substrate S in the film forming process region 20A correspond to the film raw material of the present invention.
As for the rotary cathode unit 22, the film raw material is adhered to the surface of the substrate S according to the same principle as the rotary cathode unit 21 described above.

  The present invention is characterized in that the cylindrical target 81 of the rotating cathode unit 21 rotates during sputtering. That is, since the cylindrical target 81 is rotating, the cylindrical target 81 always moves with respect to the leakage magnetic field generated by the magnetic body unit 88, so that a region that is not easily eroded is generated on the surface of the cylindrical target 81. Any area of the surface is eroded almost uniformly. That is, it is characterized in that a non-erosion region hardly occurs on the surface of the target as in the case of using a conventional flat target. For this reason, it is possible to improve the utilization rate of the target due to the generation of the non-erosion region, and to reduce the cost required for film formation.

  In the present invention, since a non-erosion region hardly occurs on the surface of the cylindrical target 81, there is almost no accumulation of an insulator (in this embodiment, a complete oxide or incomplete oxide of silicon). For this reason, abnormal discharge (arc discharge) due to accumulation of insulating reactants is unlikely to occur, and this makes it possible to form a thin film with few defects and excellent film quality.

  In particular, in the reactive sputtering apparatus, it is necessary to introduce a reactive gas into the film forming process region 20A and the reaction process region 60A, so that damage of the thin film due to abnormal discharge of the target has been a serious problem. In the conventional reactive sputtering apparatus, the amount of the insulating material accumulated in the non-erosion region is reduced by reducing the concentration of the reactive gas introduced into the film forming process region 20A or the reaction process region 60A, thereby preventing abnormal discharge. However, since the concentration of the reactive gas is small, the reaction rate between the film raw material and the reactive gas is low, and there is a disadvantage that it takes a long time for film formation.

  On the other hand, in the present invention, by rotating the target, the occurrence of abnormal discharge can be prevented and the film quality can be greatly improved. In addition, since abnormal discharge due to the accumulation of the insulator hardly occurs, the amount of the reactive gas introduced into the film forming process region 20A and the reaction process region 60A can be increased. Thereby, the reaction rate between the film raw material and the reactive gas can be increased. For this reason, the film formation rate is improved and the film formation time can be shortened.

(Reaction process area 60A)
Subsequently, the reaction process region 60A will be described. As described above, in the reaction process region 60A, the film raw material adhered to the surface of the substrate S in the film formation process region 20A is subjected to a reaction treatment to form a thin film made of a compound of the film raw material or an incomplete compound.
At the same time, in the reaction process region 60A, a pretreatment process for performing plasma treatment on the surface of the substrate S before the thin film formation and a posttreatment process for performing plasma treatment on the surface of the substrate S after the thin film formation are performed.

  As shown in FIG. 6, an opening 11a for installing the plasma generating means 60 is formed on the wall surface of the vacuum vessel 11 corresponding to the reaction process region 60A. A pipe 75a is connected to the reaction process region 60A. A mass flow controller 72 is connected to one end of the pipe 75 a, and this mass flow controller 72 is further connected to a reactive gas cylinder 71. For this reason, it is possible to supply oxygen gas from the reactive gas cylinder 71 into the reaction process region 60A.

  The wall surface of the partition wall 14 facing the reaction process region 60A is covered with a protective layer made of pyrolytic boron nitride (Pyrolytic Boron Nitride). Furthermore, a protective layer made of pyrolytic boron nitride is also coated on the inner wall surface of the vacuum vessel 11 facing the reaction process region 60A. The pyrolytic boron nitride is coated on the partition wall 14 and the inner wall surface of the vacuum vessel 11 by a thermal decomposition method using a chemical vapor deposition method. Such a protective layer is preferably provided as necessary.

  The plasma generating means 60 is provided facing the reaction process region 60A. The plasma generating means 60 of this embodiment includes a case body 61, a dielectric plate 62, an antenna 63, a matching box 64, and a high frequency power supply 65.

  The case body 61 has a shape for closing the opening 11a formed on the wall surface of the vacuum vessel 11, and is fixed so as to close the opening 11a of the vacuum vessel 11 with a bolt (not shown). By fixing the case body 61 to the wall surface of the vacuum vessel 11, the plasma generating means 60 is attached to the wall surface of the vacuum vessel 11. In the present embodiment, the case body 61 is made of stainless steel.

The dielectric plate 62 is formed of a plate-like dielectric. In this embodiment, the dielectric plate 62 is made of quartz, but the material of the dielectric plate 62 is not limited to such quartz, but may be made of a ceramic material such as Al ₂ O ₃ . The dielectric plate 62 is fixed to the case body 61 with a fixing frame (not shown). By fixing the dielectric plate 62 to the case body 61, an antenna accommodating chamber 61 </ b> A is formed in a region surrounded by the case body 61 and the dielectric plate 62.

  The dielectric plate 62 fixed to the case body 61 is provided facing the inside of the vacuum vessel 11 (reaction process region 60A) through the opening 11a. At this time, the antenna accommodating chamber 61 </ b> A is separated from the inside of the vacuum container 11. That is, the antenna accommodating chamber 61 </ b> A and the inside of the vacuum container 11 form an independent space in a state where the antenna plate is partitioned by the dielectric plate 62. Further, the antenna accommodating chamber 61 </ b> A and the outside of the vacuum container 11 form an independent space in a state of being partitioned by the case body 61. In the present embodiment, the antenna 63 is installed in the antenna accommodating chamber 61A formed as an independent space in this way. In addition, airtightness is maintained between the antenna housing chamber 61A and the inside of the vacuum vessel 11 and between the antenna housing chamber 61A and the outside of the vacuum vessel 11 by O-rings.

  In this embodiment, the pipe 16a-2 branches from the pipe 16a-1. The pipe 16a-2 is connected to the antenna accommodating chamber 61A, and has a role as an exhaust pipe when the inside of the antenna accommodating chamber 61A is evacuated to be in a vacuum state.

  Valves V <b> 1 and V <b> 2 are provided in the piping 16 a-1 at positions where the vacuum pump 15 a communicates with the inside of the vacuum vessel 11. Further, a valve V3 is provided in the pipe 16a-2 at a position where it communicates from the vacuum pump 15a to the inside of the antenna accommodating chamber 61A. By closing either of the valves V2 and V3, gas movement between the inside of the antenna accommodating chamber 61A and the inside of the vacuum vessel 11 is prevented. The pressure inside the vacuum vessel 11 and the pressure inside the antenna accommodating chamber 61A are measured by a vacuum gauge (not shown).

  In the present embodiment, the sputtering apparatus 1 includes a control device (not shown). The output of the vacuum gauge is input to this control device. The control device has a function of adjusting the degree of vacuum inside the vacuum vessel 11 and inside the antenna accommodating chamber 61A by controlling the exhaust by the vacuum pump 15a based on the input measurement value of the vacuum gauge. In the present embodiment, the control device controls the opening and closing of the valves V1, V2, and V3, so that the inside of the vacuum container 11 and the inside of the antenna housing chamber 61A can be exhausted simultaneously or independently.

The antenna 63 is means for receiving electric power from the high frequency power supply 65 to generate an induction electric field inside the vacuum vessel 11 (reaction process region 60A) and to generate plasma in the reaction process region 60A. The antenna 63 of the present embodiment includes a tubular main body portion made of copper, and a covering layer made of silver covering the surface of the main body portion. That is, the main body of the antenna 63 is formed into a circular tube shape with copper that is inexpensive and easy to process and has low electrical resistance, and the surface of the antenna 63 is covered with silver having a lower electrical resistance than copper. Thereby, the impedance of the antenna 63 with respect to a high frequency is reduced, and the efficiency of generating plasma is increased by flowing a current through the antenna 63 efficiently.
The sputtering apparatus 1 according to the present embodiment is configured to generate a reactive gas plasma in the reaction process region 60 </ b> A by applying an AC voltage of 1 to 27 MHz to the antenna 63 from the high frequency power supply 65.

The antenna 63 is connected to a high frequency power supply 65 via a matching box 64 that houses a matching circuit. A variable capacitor (not shown) is provided in the matching box 64.
The antenna 63 is connected to the matching box 64 via a conducting wire part. The conductor portion is made of the same material as that of the antenna 63. The case body 61 is formed with an insertion hole for inserting the conducting wire portion, and the antenna 63 inside the antenna accommodating chamber 61A and the matching box 64 outside the antenna accommodating chamber 61A are led through the inserting hole. Connected through the unit. A seal member is provided between the conductor portion and the insertion hole, and airtightness is maintained inside and outside the antenna accommodating chamber 61A.

  A grid 66 is provided between the antenna 63 and the rotating drum 13 as ion annihilation means. The grid 66 is for extinguishing part of ions and part of electrons generated by the antenna 63. The grid 66 is a hollow member made of a conductor and is grounded. In order to flow a cooling medium (for example, cooling water) inside the grid 66 made of a hollow member, a hose (not shown) for supplying the cooling medium is connected to an end of the grid 66.

  Further, a reactive gas supply means 70 for supplying a reactive gas is provided in and around the reaction process region 60A. The reactive gas supply means 70 includes a reactive gas cylinder 71 for storing the reactive gas, a mass flow controller 72 for adjusting the flow rate of the reactive gas supplied from the reactive gas cylinder 71, and the reactive gas in the reaction process region 60A. A pipe 75a to be introduced is provided as a main component. In the present embodiment, oxygen gas is used as the reactive gas, similarly to the reactive gas introduced into the film forming process region 20A described above.

  The reactive gas cylinder 71 and the mass flow controller 72 can employ the same devices as the sputtering gas cylinder 32 and the mass flow controller 31 in the film forming process region 20A. The reactive gas is not limited to oxygen gas, and is appropriately selected from nitrogen gas, fluorine gas, ozone gas, and the like according to the material of the target thin film. Further, in addition to the reactive gas, an inert gas such as argon may be mixed and introduced. By doing so, since the density of reactive gas radicals increases due to the generation of plasma, which will be described later, the reactivity between the film raw material and the reactive gas increases, and the efficiency of the plasma processing can be improved. Become.

  When oxygen gas is introduced from the reactive gas cylinder 71 into the reaction process region 60A through the pipe 75a, power is supplied to the antenna 63 from the high frequency power supply 65, and plasma is generated in a region facing the antenna 63 in the reaction process region 60A. In the film raw material formed on the surface of the substrate S, a component that has not been completely oxidized in the film forming process region 20A is subjected to a reaction treatment to become an oxide or incomplete oxide of the film raw material.

Specifically, oxygen gas is introduced from the reactive gas supply means 70, and silicon (Si), silicon oxide (SiO ₂ ) which is a complete oxide of silicon, or incomplete oxide (SiO _x1 (SiO _x1 ( Here, 0 <x1 <2)) is generated. Further, incomplete silicon oxide (SiO _x2 : where 0 <x2 <2) is oxidized in the film raw material, and silicon oxide (SiO ₂ ) or incomplete oxide (SiO _y ) which is a complete oxide of silicon. (Where 0 <y <2 and y> x2)).

Next, a method for forming a thin film made of silicon oxide (SiO ₂ ) on the surface of the substrate S using the sputtering apparatus 1 will be described.
First, the substrate S is set on the rotary drum 13 outside the vacuum vessel 11 and accommodated in the load lock chamber 11 </ b> B of the vacuum vessel 11. Then, the rotating drum 13 is moved to the thin film forming chamber 11A along a rail (not shown). The inside of the vacuum vessel 11 is sealed with the door 11C and the door 11D closed, and the inside of the vacuum vessel 11 is brought to a high vacuum state of about 10 ⁻¹ to 10 ⁻⁵ Pa using the vacuum pump 15a.

Next, a mixed gas of argon gas and oxygen gas is introduced from the sputtering gas supply means 30 into the film forming process region 20A (sputtering gas introduction step). In this state, power is supplied from the AC power supply 24 to the cylindrical target 81 to sputter the cylindrical target 81. The flow rate of argon gas is set to an appropriate flow rate within a range of about 250 to 1000 sccm. In this state, when the rotating drum 13 rotates and the substrate S is transported to the film forming process region 20A, silicon (Si), which is a film raw material, and an incomplete oxide of silicon (SiO _x : here) 0 <x <2), complete oxide (SiO ₂ ) is deposited (sputtering process). During this time, the cylindrical target 81 is in a state of being rotated by receiving power from the DC power source 96.

  Note that a moving or rotary shielding plate may be provided between the rotary drum 13 and the rotary cathode units 21 and 22 to start and stop the sputtering process. In this case, before the start of the sputtering process, the position of the shielding plate is arranged at a blocking position where the film source material moving from the rotary cathode units 21 and 22 does not reach the substrate S, and at the start of the sputtering process, the rotary cathode unit 21 is placed. , 22 is moved to a non-blocking position where the film raw material moving to the substrate S arrives.

Next, the rotary drum 13 is rotated to transport the substrate S to the reaction process region 60A (substrate transport process).
Subsequently, oxygen gas is introduced from the reactive gas supply means 70 into the reaction process region 60A (reactive gas introduction step). In this state, an alternating voltage is applied from the high frequency power supply 65 to the antenna 63 to generate oxygen gas plasma inside the reaction process region 60A (plasma generation step). Since oxygen gas plasma is generated inside the reaction process region 60A, silicon (Si) or an incomplete oxide of silicon (SiO _x : where 0 <x <2) reacts with oxygen gas and is converted into silicon oxide (SiO ₂ ) or incomplete oxide of silicon (SiO _x : 0 <x <2). As a result, an intermediate thin film is formed on the surface of the substrate S.

A plurality of intermediate thin films are stacked by sequentially rotating the rotating drum 13 and sequentially repeating the sputtering process in the film forming process region 20A and the reaction process in the reaction process region 60A, and a final thin film having a desired film thickness is obtained. Form.
When the above steps are completed, the rotation of the rotary drum 13 is stopped, the vacuum state inside the vacuum vessel 11 is released, and the rotary drum 13 is taken out from the vacuum vessel 11. The substrate holding plate 13a is removed from the frame 13b, and the substrate S is collected.

(Second Embodiment)
Next, a sputtering apparatus according to the second embodiment will be described with reference to FIG. FIG. 7 is an explanatory view illustrating a state of the sputtering apparatus according to the second embodiment as viewed from the top surface by taking a cross section.

  As shown in this figure, the sputtering apparatus 2 of the second embodiment is provided with another film forming process region 40A in addition to the film forming process region 20A, so that the sputtering apparatus 1 of the first embodiment is provided. And different. That is, in the sputtering apparatus 2 according to the second embodiment, in addition to the film forming process region 20A and the reaction process region 60A, a film forming process region 40A is formed at a position separated from these regions.

  Similar to the film forming process region 20A of the first embodiment, the film forming process region 20A includes a sputtering unit 20 having rotating cathode units 21 and 22, and a sputtering gas supply unit 30 for introducing a sputtering gas. Is provided. Similarly, the film forming process region 40A is also provided with a sputtering means 40 having rotating cathode units 41 and 42 and a sputtering gas supply means 50 for introducing a sputtering gas. Each of the rotary cathode units 41 and 42 has the same configuration as that of the rotary cathode units 21 and 22. Since the configuration of the rotary cathode units 21 and 22 has been described in the first embodiment, the description thereof is omitted here.

  In the present embodiment, targets of different materials are used for the rotary cathode units 21 and 22 and the rotary cathode units 41 and 42. For example, silicon is used as the target in the rotary cathode units 21 and 22, and titanium is used as the target in the rotary cathode units 41 and 42. In this way, by using targets of different materials, it is possible to form a composite thin film by laminating thin films made of different materials. Thereby, it is possible to give variations to the physical and optical characteristics of the thin film to be formed. Specifically, for example, an intermediate thin film made of silicon oxide and an intermediate thin film made of titanium oxide can be sequentially laminated to form a composite thin film having an intermediate refractive index between silicon oxide and titanium oxide.

(Third embodiment)
Next, a sputtering apparatus according to the third embodiment will be described.
The sputtering apparatus 3 of the present embodiment has the same configuration as that of the sputtering apparatus 1 of the first embodiment, but unlike the sputtering apparatus 1 of the first embodiment, the film forming process region 20A and the reaction process region. It is characterized in that the partition walls 12 and 14 partitioning 60A are not provided.

This is because the non-erosion region is less likely to be generated by the rotation of the cylindrical target 81, and the accumulation of the insulator (reaction product of the film raw material and the reactive gas) is also prevented. This is because it is not necessary to provide the partition wall 12 for blocking the flow of the reactive gas and the partition wall 14 for blocking the flow of the reactive gas to the film forming process region 20A. Conversely, a reactive gas introduced into the reaction process region 60A is positively introduced into the film formation process region 20A, and the film source material generated by sputtering reacts with the reactive gas to increase the film formation rate. From the viewpoint of raising, it is more convenient not to provide the partition wall 12 and the partition wall 14.
Thus, according to the sputtering apparatus 3 of this embodiment, since it is not necessary to provide the partition walls 12 and 14, it becomes possible to simplify the structure.

  Although the example which applied this invention to RF magnetron sputtering was demonstrated in the above example, if it is an apparatus which can apply the structure which rotates a target in a reactive sputtering apparatus, it will not be limited to this. Needless to say, the present invention can also be applied to other magnetron sputtering apparatuses such as DC magnetron sputtering.

It is explanatory drawing which shows the state which took the cross section of the sputtering device and was seen from the upper surface. It is explanatory drawing which shows the state seen from the side surface which took the longitudinal cross-section of the sputtering device of FIG. It is explanatory drawing which expanded and showed the film-forming process area periphery of the sputtering device of FIG. It is a perspective view of a rotating cathode unit. It is Xa-Xb longitudinal cross-sectional view of the rotating cathode unit of FIG. It is explanatory drawing which expanded and showed the reaction process area | region periphery of the sputtering device of FIG. It is explanatory drawing which shows the state which took the cross section of the sputtering device which concerns on 2nd Embodiment, and was seen from the upper surface. It is explanatory drawing which shows the state which took the cross section of the sputtering device which concerns on 3rd Embodiment, and was seen from the upper surface. It is explanatory drawing which shows the state seen from the upper surface, taking the cross section of the conventional reactive sputtering apparatus. It is explanatory drawing explaining the subject of the flat target used for the conventional reactive sputtering apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sputtering apparatus 2 Sputtering apparatus 3 Sputtering apparatus 11 Vacuum container 11a Opening 11A Thin film formation chamber 11B Load lock chamber 11C Door 11D Door 12 Partition wall 13 Rotating drum (substrate conveyance means)
13a Substrate holding plate 13b Frame 13c Fastener 14 Partition wall 15a Vacuum pump 15b Vacuum pump 16a-1 Piping 16a-2 Piping 16b Piping 17 Drum rotating motor 17a Motor rotating shaft 18 Drum rotating shaft 20 Sputtering means 20A Deposition process area 21 Rotation Cathode unit 22 Rotating cathode unit 23 Transformer 24 AC power supply 26 Insulating member 30 Sputter gas supply means 31 Mass flow controller 32 Sputter gas cylinder 33 Mass flow controller 34 Reactive gas cylinder 35a Pipe 35b Inlet 35c Pipe 35d Pipe 40 Sputter means 40A Film formation process region 41 Rotating cathode unit 42 Rotating cathode unit 50 Sputtering gas supply means 60 Plasma generating means 60A Reaction process area 61 Case body 61A Antenna accommodating chamber 62 Dielectric plate 63 Antenna 64 Matching box 65 High frequency power supply 66 Grid 70 Reactive gas supply means 71 Reactive gas cylinder 72 Mass flow controller 75a Piping 81 Cylindrical target 82 Cap 83 Cap 84 Support rod (target rotating means)
85 Fixed plate (target rotation means)
86 Fixed plate (target rotation means)
87 Yoke 88 Magnetic body unit (magnetic field forming means)
88a Central magnet (magnetic field forming means)
88b Outer magnet (magnetic field forming means)
88c Outer magnet (magnetic field forming means)
89 Target side gear (target rotation means)
91 Box 92 Intermediate gear (target rotation means)
93 Target rotation motor (target rotation means)
94 Motor side gear (target rotation means)
95 Shaft 96 DC power supply 101 Sputtering device 111 Vacuum vessel 113 Substrate holder 120A Film formation process area 121 Sputter electrode 122 Yoke 123a Central magnet 123b Outer magnet 123c Outer magnet 125 Partition wall 129 Target 140A Film formation process area 141 Sputter electrode 145 Partition wall 149 Target 160A Reaction process region 165 Partition wall S Substrate (base)
V1 Valve V2 Valve V3 Valve Xa-Xb Center axis Za-Zb Rotation axis

Claims (5)

A sputtering apparatus for forming a thin film on a substrate,
A vacuum container having a film forming process region and a reaction process region formed at positions spatially separated from each other;
Substrate transport means capable of transporting the substrate between the film formation process region and the reaction process region;
A sputtering gas introduction means for introducing a sputtering gas into the film forming process region;
Sputtering means for performing sputtering with the sputtering gas in the film forming process region and attaching a film raw material to the surface of the substrate;
Reactive gas introduction means for introducing a reactive gas into the reaction process region;
Plasma generating means for generating a plasma in the reaction process region to react the film raw material adhering to the surface of the substrate with the reactive gas;
With
The sputtering means includes
A cylindrical target rotatable around a central axis along the longitudinal direction;
Magnetic field forming means for forming a magnetic field on the surface of the cylindrical target;
A sputtering apparatus comprising: a target rotating unit that rotates the cylindrical target with respect to the magnetic field forming unit. The sputtering means is disposed adjacent to the film forming process area,
The sputtering apparatus according to claim 1, further comprising: an AC power source that alternately applies a voltage to the pair of sputtering units disposed adjacent to each other. The vacuum container has a plurality of film forming process regions,
In each of the plurality of film forming process regions, the sputtering means including the cylindrical target is disposed,
The cylindrical target disposed in one of the plurality of film forming process regions is formed of a material different from the cylindrical target disposed in any one of the other. The sputtering apparatus according to claim 1 or 2.   The sputtering apparatus according to claim 1, wherein the film forming process region does not have a partition wall for preventing gas from flowing into the inside. A sputtering method for forming a thin film on a substrate,
A sputtering gas introduction step of introducing a sputtering gas into a film forming process area partitioned in a vacuum vessel;
A sputtering step of sputtering a cylindrical target with the sputtering gas in the film forming process region and attaching a film raw material to the surface of the substrate;
A substrate transporting step for transporting the substrate to a reaction process region formed at a position spatially separated from the film forming process region;
A reactive gas introduction step of introducing a reactive gas into the reaction process region;
Performing a plasma generation step of generating a plasma in the reaction process region to react the film raw material adhering to the surface of the substrate with the reactive gas;
In the sputtering process,
A sputtering method, wherein a magnetic field is formed on a surface of the cylindrical target, and the cylindrical target is rotated around a central axis along a longitudinal direction thereof.

Images