Magnetron sputtering device and sputtering cathode thereof

Abstract

The invention relates to a magnetron sputtering device and a sputtering cathode thereof, the sputtering cathode comprises a target material, a first magnetic field generating device and a second magnetic field generating device, and the target material is provided with a target material surface; the first magnetic field generating device is used for forming a first magnetic field parallel to the surface of the target on the surface of the target; the second magnetic field generating device is used for forming a second magnetic field perpendicular to the surface of the target on the surface of the target; wherein under the combined action of the first magnetic field and the second magnetic field, the plasma area on the surface of the target material is expanded towards the substrate, so that the incident angle distribution of sputtering particles to the substrate is changed, and the sputtering deposition of the side wall of the deep hole or the groove is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of magnetron sputtering, in particular to a magnetron sputtering device and a sputtering cathode thereof. BACKGROUND

[0002] With the continuous development of microelectronic devices, MEMS structures and advanced optical elements, there are often high aspect ratio three-dimensional topographic structures such as deep holes, grooves and microchannels on the surface of the devices. It is an important link to ensure the performance and reliability of the devices to achieve uniform and dense film deposition in these structures.

[0003] As the most widely used physical vapor deposition (PVD) method at present, magnetron sputtering has the advantages of high deposition rate, good film purity and wide range of applicable materials. However, the sputtering atoms and ions in the deposition process mainly follow the principle of straight-line propagation (line-of-sight transmission), which leads to a significant difference in deposition rate between the sidewall area and the opening area inside the high aspect ratio hole or groove, and the problem of non-uniform film deposition, i.e. "top accumulation, bottom and sidewall deficiency", easily occurs. SUMMARY

[0004] Therefore, it is necessary to provide a magnetron sputtering device and a sputtering cathode thereof to solve the problem of low deposition rate of the sidewall film of the high aspect ratio hole or groove.

[0005] To solve the above technical problems, the present application provides a sputtering cathode, which comprises:

[0006] a target material having a target material surface;

[0007] a first magnetic field generating device for forming a first magnetic field parallel to the target material surface on the target material surface;

[0008] a second magnetic field generating device for forming a second magnetic field perpendicular to the target material surface on the target material surface;

[0009] Under the joint action of the first magnetic field and the second magnetic field, the plasma region of the target material surface is expanded towards the substrate direction, so as to change the incident angle distribution of the sputtering particles to the substrate, thereby improving the sputtering deposition of the sidewall of the deep hole or groove.

[0010] In some embodiments, the second magnetic field generating device is an electromagnetic coil assembly.

[0011] In some embodiments, the sputtering cathode further comprises a flange plate, a main body frame and a water-cooled plate, the cross section of the main body frame is annular, the water-cooled plate and the target material are stacked, the flange plate and the water-cooled plate are respectively arranged at the lower opening and the upper opening corresponding to the main body frame, and the electromagnetic coil assembly is arranged in the space enclosed by the main body frame, the flange plate and the water-cooled plate.

[0012] In some embodiments, the electromagnetic coil assembly is arranged around the inner ring of the main frame, and includes a coil frame and a coil, with the coil mounted on the coil frame.

[0013] In some embodiments, the main frame includes an upper frame and a lower frame detachably connected to the upper frame. The free ends of the upper frame and the lower frame are provided with limiting portions extending horizontally. The coil bobbin includes a vertically arranged bobbin body and bobbin flanges extending horizontally from both ends of the bobbin body. The bobbin flanges abut against the limiting portions and form a space for accommodating the coil.

[0014] In some embodiments, the coil frame further includes a water-cooling channel fitted to the inner side of the frame body.

[0015] In some embodiments, the limiting portion of the lower frame extends toward the center and is integrally connected to form a support plate.

[0016] In some embodiments, the first magnetic field generating device includes a plurality of permanent magnets and a back plate for supporting the permanent magnets, and the first magnetic field generating device partially overlaps with the coil in the height direction.

[0017] In some embodiments, multiple guide shafts with a back plate and a water-cooling plate through them are fixed on the support plate for installation guidance.

[0018] To address the aforementioned technical problems, this application also provides a magnetron sputtering apparatus, which includes a vacuum chamber and a sputtering cathode as described above, with the sputtering cathode disposed within the vacuum chamber.

[0019] The magnetron sputtering apparatus and sputtering cathode of this application, by adding a second magnetic field perpendicular to the target surface on the basis of a first magnetic field, under the combined action of the first and second magnetic fields, causes the plasma region on the target surface to extend toward the substrate, thereby changing the incident angle distribution of sputtered particles toward the substrate, so as to improve the sputtering deposition on the sidewalls of deep holes or grooves. Attached Figure Description

[0020] Figure 1 This is a schematic diagram illustrating the structural principle of a magnetron sputtering device in the prior art.

[0021] Figure 2 This is a schematic diagram illustrating the structural principle of the magnetron sputtering device of this application;

[0022] Figure 3 A three-dimensional structural schematic diagram of a sputtering cathode provided in an embodiment of this application;

[0023] Figure 4 for Figure 3 A three-dimensional structural schematic diagram of the sputtering cathode from another perspective;

[0024] Figure 5 forFigure 3 A cross-sectional structural schematic diagram of the sputtering cathode is shown in FIG. 1.

[0025] Figure 6 A cross-sectional structural schematic diagram of the sputtering cathode is shown in FIG. 1. Figure 5 An enlarged structural schematic diagram of the sputtering cathode A part is shown in FIG. 2.

[0026] Figure 7 An enlarged structural schematic diagram of the sputtering cathode A part is shown in FIG. 2. Figure 3 A three-dimensional structural schematic diagram of the coil frame of the sputtering cathode is shown in FIG. 3.

[0027] Figure 8 A three-dimensional structural schematic diagram of the coil frame of the sputtering cathode is shown in FIG. 3. Figure 3 A three-dimensional structural schematic diagram of the main frame of the sputtering cathode is shown in FIG. 4. DETAILED DESCRIPTION

[0028] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of ways other than those described herein, and by persons skilled in the art without departing from the scope of the present application, and therefore the present application is not limited to the specific embodiments disclosed below.

[0029] In the description of the present application, if these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0030] In addition, if these terms "first", "second" appear, these terms are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features referred to. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, if the term "a plurality of" appears, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0031] In the present application, unless specifically defined otherwise, if there is an appearance of the terms "installation", "connection", "connection", "fixation" and the like, these terms should be understood in a broad sense. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] In the present application, unless specifically defined otherwise, if there is a description of the first feature "on" or "below" the second feature and the like, it means that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0033] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on another element or there can be a middle element. If an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the present application are for illustrative purposes only and are not the only embodiment.

[0034] The horizontal magnetic field mentioned in the present application is relative to the target surface, and most of the magnetic force lines are parallel to the target surface. The vertical magnetic field is relative to the target surface, and most of the magnetic force lines are perpendicular to the target surface. Please refer to Figure 1 , Figure 1Figure 1 is a schematic diagram of the structure and principle of a magnetron sputtering device in the prior art. In the prior art, a plurality of permanent magnets 2 are arranged behind the target material 1. The plurality of permanent magnets 2 can form a horizontal magnetic field on the surface of the target material 1, and an area 3 of plasma is generated around the horizontal magnetic field. A large number of electrons are gathered in the area 3 of plasma. When argon ions hit the target material 1, sputtering particles (mainly composed of target material atoms 5 and target material ions 6) are generated. The target material atoms 5, after leaving the surface of the target material 1, hit the electrons when passing through the area 3 of plasma, and have a probability of becoming target material ions 6. The target material atoms 5 that do not become target material ions 6 are deposited on the surface or sidewall of the substrate 4 in a straight line motion (only a small part can be deposited on the sidewall). The target material ions 6 are accelerated in a direction almost perpendicular to the surface of the substrate 4 under the action of an electric field and are deposited on the surface of the substrate 4. This method is good for planar substrates 4, but the deposition efficiency is very low if the substrate 4 has deep holes or deep grooves.

[0035] Further, refer to Figure 2 , Figure 2 Figure 2 is a schematic diagram of the structure and principle of a magnetron sputtering device according to the present application. Compared with the prior art, the difference is that an electromagnetic coil 7 is arranged below the permanent magnets 2. The electromagnetic coil 7 can generate a vertical magnetic field. Under the joint action of the horizontal magnetic field and the vertical magnetic field, the area 3 of plasma on the surface of the target material 1 expands towards the substrate 4. At this time, the sputtering particles ionize to generate target material ions 6 when passing through the head of the area of plasma. The target material ions 6 here have an incident angle α close to vertical (normal direction) when being shot towards the deep hole. Under the action of an electric field, the target material ions 6 can be directionally and efficiently shot towards the deep hole. Thus, the sputtering deposition of the sidewall of the deep hole or groove is improved.

[0036] Further, refer to Figures 3-6 , Figure 3 Figure 3 is a schematic diagram of the three-dimensional structure of a sputtering cathode according to an embodiment of the present application; Figure 4 Figure 4 is a schematic diagram of the cross-sectional structure of the sputtering cathode shown in Figure 3, Figure 3 Figure 5 is a schematic diagram of the cross-sectional structure of the sputtering cathode shown in Figure 3, Figure 5 Figure 6 is a schematic diagram of the cross-sectional structure of the sputtering cathode shown in Figure 3, Figure 3 Figure 7 is a schematic diagram of the cross-sectional structure of the sputtering cathode shown in Figure 3, Figure 6 Figure 8 is a schematic diagram of the cross-sectional structure of the sputtering cathode shown in Figure 3, Figure 5An enlarged structural schematic diagram of the sputtering cathode A part is shown. In this embodiment, the sputtering cathode includes a target material 11, a first magnetic field generating device 12, a second magnetic field generating device 13, a flange plate 14, a main frame 15, and a water-cooled plate 16. Among them, the target material 11 is preferably a rectangular target material 11, which has a target material 11 surface; the first magnetic field generating device 12 is preferably a permanent magnet 121, which is used to form a first magnetic field parallel to the target material 11 surface on the target material 11 surface, and the second magnetic field generating device 13 is preferably an electromagnetic coil assembly, which is used to form a second magnetic field perpendicular to the target material 11 surface on the target material 11 surface. Of course, in other embodiments, other magnetic field generating devices such as magnets can also be used, but the electromagnetic coil assembly is more convenient to adjust. Under the joint action of the first magnetic field and the second magnetic field, the plasma region on the target material 11 surface expands towards the substrate direction, thereby changing the incident angle distribution of the sputtering particles to the substrate, so as to improve the sputtering deposition of the deep hole or groove sidewall. Among them, the water-cooled plate 16 and the target material 11 are stacked, the flange plate 14 and the water-cooled plate 16 are respectively arranged at the corresponding lower opening and upper opening of the main frame 15, and the electromagnetic coil assembly is arranged in the space enclosed by the main frame 15, the flange plate 14 and the water-cooled plate 16.

[0037] Further, please refer to Figure 8 , Figure 8 for Figure 3 An enlarged structural schematic diagram of the sputtering cathode's main frame is shown. The main frame 15 of this embodiment includes an upper frame 151 and a lower frame 152 detachably connected with the upper frame 151. The free ends of the upper frame 151 and the lower frame 152 are both extended in the horizontal direction to be provided with a limiting part 153, and the limiting part 153 of the lower frame 152 is extended towards the center to be integrated into a support plate 154. Among them, the upper frame 151 and the lower frame 152 are both made of insulating material, and in order to increase the sealing performance, a sealing ring (not marked) is also arranged between the upper frame 151 and the lower frame 152. The main frame 15 is formed in a split manner, which is beneficial to reduce the processing cost and improve the disassembly efficiency. In order to protect the main frame 15, a protective plate 19 is also arranged around the outside of the main frame 15.

[0038] Please refer to Figure 7 , Figure 7 for Figure 3A perspective view of the coil frame of the sputtering cathode is shown. The electromagnetic coil assembly is arranged around the inner ring of the main frame 15, which includes a coil frame 17 and a coil (not shown in the figure), and the coil is mounted on the coil frame 17. Specifically, the coil frame 17 includes a vertically arranged frame body 171 and frame flanges 172 extending horizontally from both ends of the frame body 171, and the frame flanges 172 abut against the limiting portion 153 and form a space for accommodating the coil. The coil is wound around the coil frame 17 from top to bottom or from bottom to top, and according to the Ampere's right-hand rule, the direction of the magnetic field generated by the coil is a vertical magnetic field. For the size of the vertical magnetic field, those skilled in the art can adjust it according to the actual situation.

[0039] Further, the coil generates a large amount of heat after being energized, in order to dissipate heat from the coil, the coil frame 17 further includes a water cooling channel 173 arranged on the inner side of the frame body 171, which can quickly dissipate heat from the coil by passing water or other liquids.

[0040] It should be noted that the first magnetic field generating device 12 includes a plurality of permanent magnets 121 and a back plate 122 for carrying the permanent magnets 121, and the first magnetic field generating device 12 partially overlaps with the coil in the height direction. Compared with arranging the second magnetic field generating device 13 outside the main frame 15, this way of arranging both the first magnetic field generating device 12 and the second magnetic field generating device 13 inside the main frame 15 has small modification to the sputtering cathode and is more convenient to adjust.

[0041] In some embodiments, a plurality of guide shafts 18 for installing guides are fixed on the support plate 154 and pass through the back plate 122 and the water cooling plate 16.

[0042] In some embodiments, the sputtering cathode further includes an adjusting device 20 for adjusting the magnetic field strength of the first magnetic field, which is spaced apart and has one end fixed to the side of the flange plate 14 away from the first magnetic field generating device 12 and the other end connected to the back plate 122.

[0043] The application also discloses a magnetron sputtering device, which comprises a vacuum chamber and the sputtering cathode of the foregoing embodiments, and the sputtering cathode is arranged in the vacuum chamber.

[0044] The magnetron sputtering device and the sputtering cathode thereof of the application change the incident angle distribution of the sputtering particles to the substrate by expanding the plasma region on the surface of the target material to the substrate direction under the joint action of the first magnetic field and the second magnetic field perpendicular to the target surface, so as to improve the sputtering deposition on the sidewall of the deep hole or groove.

[0045] Any combination of the technical features in the above-described embodiments can be made, and for the sake of brevity, not all possible combinations are described, however, it is to be understood that the application embraces all such possible combinations.

[0046] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that for ordinary skilled persons in the art, some modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A sputter cathode, characterized in that The sputtering cathode comprises: a target material having a target material surface; a first magnetic field generating device for forming a first magnetic field parallel to the target material surface on the target material surface; a second magnetic field generating device for forming a second magnetic field perpendicular to the target material surface on the target material surface; wherein under the joint action of the first magnetic field and the second magnetic field, a plasma region of the target material surface is expanded towards the substrate direction, thereby changing the incident angle distribution of sputtering particles to the substrate to improve the sputtering deposition of deep hole or groove sidewalls.

2. The sputter cathode of claim 1, characterized in that The second magnetic field generating device is an electromagnetic coil assembly.

3. The sputter cathode of claim 2, characterized in that The sputtering cathode further comprises a flange plate, a main frame and a water-cooled plate, the main frame has a ring-shaped cross section, the water-cooled plate and the target material are stacked, the flange plate and the water-cooled plate are respectively arranged at the corresponding lower opening and upper opening of the main frame, and the electromagnetic coil assembly is arranged in a space enclosed by the main frame, the flange plate and the water-cooled plate.

4. The sputter cathode of claim 3, characterized in that The electromagnetic coil assembly is arranged around the inner ring of the main frame, and comprises a coil skeleton and a coil mounted on the coil skeleton.

5. The sputter cathode of claim 4, characterized in that The main frame comprises an upper frame and a lower frame detachably connected with the upper frame, the free ends of the upper frame and the lower frame are both extended in the horizontal direction to form a limiting portion, the coil skeleton comprises a skeleton main body arranged vertically and a skeleton flange horizontally extended from both ends of the skeleton main body, the skeleton flange abuts against the limiting portion and forms a space for accommodating the coil.

6. The sputter cathode of claim 5, characterized in that The coil skeleton further comprises a water-cooled channel arranged on the inner side of the skeleton main body.

7. The sputter cathode of claim 5, characterized in that The limiting portion of the lower frame is integrally formed with a support plate extending towards the center.

8. Sputter cathode according to claim 7, characterized in that The first magnetic field generating device comprises a plurality of permanent magnets and a back plate for carrying the permanent magnets, and the first magnetic field generating device partially overlaps with the coil in the height direction.

9. Sputter cathode according to claim 8, characterized in that A plurality of guide shafts for mounting guide are fixed on the support plate and pass through the back plate and the water-cooled plate.

10. A magnetron sputtering device, characterized by The magnetron sputtering device comprises a vacuum chamber and a cathode sputtering as claimed in any one of claims 1-9, and the sputtering cathode is arranged in the vacuum chamber.

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