Physical vapor deposition equipment capable of reducing back coating of wafer

Abstract

The invention provides physical vapor deposition equipment capable of reducing back coating of a wafer. The physical vapor deposition equipment comprises a deposition cavity, a supporting base and a supporting ring, wherein the supporting base and the supporting ring are located in the deposition cavity; the supporting ring is annularly arranged above the circumferential edge of the supporting base, the supporting ring comprises a first part and a second part, the center of the first part is provided with an open hole for exposing the central area of the supporting base, and the annular surface of the first part is provided with an annular surface used for being in direct contact with the back surface of a wafer in the deposition process; the first annular bulge is used for erecting the wafer on the supporting base; the second part is annularly connected to the outer side of the first part, the upper surface of the second part is lower than the first part, so that the outermost region of the back surface of the wafer is in a suspended state, and the periphery of the second part extends downwards to the side surface of the supporting base. According to the invention, the wafer back coating can be avoided while the fragment risk is effectively reduced, the wafer sticking risk is reduced, and the process yield is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuit manufacturing, in particular to integrated circuit manufacturing equipment, and in particular to a physical vapor deposition equipment capable of reducing the coating on the back side of a wafer. Background Art

[0002] Physical Vapor Deposition (PVD) is a technology that uses physical methods to vaporize the surface of solid and / or liquid material sources into gaseous atoms, molecules or partially ionized ions under vacuum conditions, and deposits a thin film with certain special functions on the surface of the substrate through a low-pressure gas or plasma process. PVD coating technology is widely used in semiconductors, optics, electronics and other fields. For example, in semiconductor manufacturing, PVD coating technology can be used to prepare thin films such as metal electrodes and insulating layers, which plays a key role in improving the performance and reliability of semiconductor devices. However, in the PVD coating process, when the particles sputtered from the target fly to the wafer, due to the influence of factors such as particle scattering, reflection, and electric and magnetic field distribution, some particles will reach the edge and back of the wafer and deposit on it, resulting in unwanted coating on the edge and back of the wafer. The coating on the edge and back of the wafer can have many adverse effects on product performance. For example, in semiconductor devices, the coating on the back of the wafer may change its electrical properties and affect the normal operation of the device; the uneven coating on the edge may cause stress concentration, reduce the mechanical strength and reliability of the wafer, and even affect the subsequent packaging process. Therefore, how to effectively prevent the coating on the edge and back of the wafer is an urgent problem to be solved in the PVD coating process.

[0003] In the prior art, to prevent the back side of the wafer from being coated, a common method is to use a pressure ring to press the wafer to prevent back side coating; another method is to completely attach the back side of the wafer, especially the edge surface of the wafer, to the support surface of the support platform to shield the back side of the wafer. However, the former method is prone to cause fragments, and the latter method is prone to cause adhesion between the wafer and the support platform, which will also cause damage to the wafer.

[0004] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present invention and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because these solutions are described in the background technology section of the present invention. Summary of the invention

[0005] In view of the shortcomings of the prior art mentioned above, the object of the present invention is to provide a physical vapor deposition device for solving the problems in the prior art of using a pressure ring to press the wafer to prevent back plating from easily causing fragments; and using a method of completely attaching the edge surface of the wafer to the supporting surface of the supporting platform to form a back shield for the wafer to prevent back side coating of the wafer, which is easy to cause adhesion between the wafer and the supporting platform, and also cause problems such as wafer damage.

[0006] To achieve the above-mentioned purpose and other related purposes, the present invention provides a physical vapor deposition device that can reduce the coating on the back side of the wafer, including: a deposition chamber, a support base and a support ring located in the deposition chamber; the support ring is arranged above the circumferential edge of the support base, the support ring includes a first part and a second part, the center of the first part has an opening that exposes the central area of ​​the support base, and the annular surface of the first part is provided with a first annular protrusion that is used to directly contact the back side of the wafer during the deposition process so as to mount the wafer on the support base; the second part is connected to the outer side of the first part, and the upper surface of the second part is lower than the first part, so that the outermost area of ​​the back side of the wafer is in a suspended state, and the periphery of the second part extends downward to the side of the support base.

[0007] Optionally, a height difference between a top surface of the first annular protrusion and a top surface of the support base is 0.2 mm-2 mm, and a radial dimension of the top surface of the first annular protrusion is 0.5 mm-1 mm.

[0008] Optionally, the periphery of the second portion extends obliquely downward to form an inclined slope surface, and the formed inclined slope surface is coplanar with the side surface of the wafer.

[0009] Optionally, the upper surface of the second part has a second annular protrusion, there is a gap between the second annular protrusion and the first annular protrusion, and the height of the second annular protrusion is lower than that of the first annular protrusion.

[0010] Optionally, a conductive material layer is provided on the surface of the second annular protrusion, and the negative bias voltage applied to the conductive material layer is greater than the negative bias voltage applied to the support base.

[0011] Optionally, an annular groove is provided between the first annular protrusion and the second annular protrusion, and an air hole connected to a vacuum device is formed on the bottom surface of the annular groove to form a negative pressure environment in the annular groove that can adsorb target particles.

[0012] Optionally, the physical vapor deposition equipment further comprises an annular cleaning gas pipeline located above the support ring, the cleaning gas pipeline being evenly spaced with a plurality of air holes opening obliquely downward for spraying inert gas toward the side of the wafer in an oblique outward manner.

[0013] In an optional solution, the support ring is made of ceramic, the surface of which is sandblasted, and the first part and the second part are integrally formed.

[0014] In another alternative, the first part and the second part are detachably connected.

[0015] Optionally, the central area of ​​the support base is higher than the peripheral area circumferentially arranged around the central area, and the physical vapor deposition equipment also includes a deposition ring, which is mounted on the surface of the peripheral area of ​​the support base and extends downward and outward, and the support ring is mounted on the deposition ring.

[0016] As described above, the physical vapor deposition equipment provided by the present invention that can reduce the coating on the back side of the wafer has the following beneficial effects: through the optimized structural design, the present invention arranges a support ring including a first part and a second part in the deposition chamber, and the annular surface of the first part is provided with a first annular protrusion for directly contacting the back side of the wafer during the deposition process to mount the wafer on the support base; the second part is connected to the outer side of the first part, and the upper surface of the second part is lower than the first part, so that the outermost area of ​​the back side of the wafer is in a suspended state, and the periphery of the second part extends downward to the side of the support base, which can effectively reduce the risk of fragmentation while effectively reducing the coating on the back side of the wafer, and can avoid adhesion between the wafer and the support base and the process kit, which helps to improve the process yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The cross-sectional structure diagram of a physical vapor deposition device capable of reducing wafer backside coating provided by the present invention in an example is shown.

[0018] Figure 2 Display as Figure 1 A local enlarged schematic diagram of the .

[0019] Figure 3 Display as Figure 2 An enlarged schematic diagram of area A in FIG.

[0020] Figure 4 It is a schematic diagram showing the working principle of setting a cleaning gas pipeline above the wafer according to the present invention.

[0021] Figure 5 A partial cross-sectional structural schematic diagram of another example of a physical vapor deposition device capable of reducing wafer backside coating provided by the present invention is shown.

[0022] Figure 6 Display as Figure 5 An enlarged schematic diagram of area B in one example.

[0023] Figure 7 Display as Figure 5An enlarged schematic diagram of area B in another example. DETAILED DESCRIPTION

[0024] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. For example, when describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional view showing the device structure will not be partially enlarged according to the general proportion, and the schematic diagram is only an example, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0025] For ease of description, spatially relative terms such as "under", "below", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the drawings. In addition, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

[0026] In the context of the present invention, a structure in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0027] It should be noted that the diagrams provided in this embodiment are only schematic illustrations of the basic concept of the present invention, and the diagrams only show the components related to the present invention rather than the number, shape and size of the components in actual implementation. The type, quantity and proportion of each component in actual implementation may be changed at will, and the layout of the components may also be more complicated. In order to make the diagrams as concise as possible, not all structures are marked in the drawings.

[0028] In existing sputtering coating equipment, in order to reduce the back coating of the wafer, a common method is to place the entire back of the wafer on a support platform so that sputtered particles cannot enter the back of the wafer. However, this method is prone to affect the coating quality due to adhesion between the coating on the edge of the wafer and the support platform. Another method is to use a pressure ring to press on the front edge of the wafer, which is prone to cause fragments. Or if these two methods are used at the same time, the above risks exist at the same time. For this reason, the inventor of this case has proposed an improvement plan after long-term and extensive research.

[0029] Specifically, Figures 1 to 3 As shown, the present invention provides a physical vapor deposition device capable of reducing backside coating of a wafer 14 , which includes a deposition chamber 11 , a support base and a support ring 13 located in the deposition chamber 11 .

[0030] The support ring 13 is arranged above the circumferential edge of the support base, and includes a first part 13a and a second part 13b. The center of the first part 13a has an opening that exposes the central area of ​​the support base. Since the wafer 14 is placed coaxially with the support base, the central area of ​​the support base corresponds to the central area of ​​the wafer 14 up and down. The annular surface of the first part 13a is provided with a first annular protrusion 131 for directly contacting the back of the wafer 14 during the deposition process to mount the wafer 14 on the support base; the second part 13b is connected to the outside of the first part 13a, and the upper surface of the second part 13b is lower than the first part 13a. Therefore, when the wafer 14 is placed on the support ring 13, the second part 13b is not in direct contact with the wafer 14, which makes the bottom of the outermost area of ​​the back of the wafer 14 not in contact with other physical structures including the support ring 13 and is in a suspended state, or the edge of the back of the wafer 14 is spaced from the support ring 13. In addition, the periphery of the second part 13b of the support ring 13 extends downward to the side of the support base.

[0031] The deposition chamber 11 may be a metal chamber such as an aluminum alloy or stainless steel, and may generally be a hollow cylindrical structure. The inner wall of the chamber may be coated with an anti-corrosion coating such as ceramic. An exhaust port is provided at the middle and lower part of the deposition chamber 11. During the coating process, the deposition chamber 11 may be grounded. A sputtering assembly is provided at the upper part of the deposition chamber 11, and the sputtering assembly includes at least a target source 17 and a sputtering power supply (not shown). The target source 17 includes, for example, a metal target material such as a copper target, an aluminum target, or other non-metallic target materials. According to different needs, the sputtering power supply may be a DC power supply or a radio frequency power supply. For example, in some examples, the physical vapor deposition device is a radio frequency sputtering device, and a radio frequency power supply is used. In some more preferred examples, the physical vapor deposition device is a magnetron sputtering device, and the sputtering assembly further includes a magnet located on the back of the target material. The magnet may be a permanent magnet and / or an electromagnet. The deposition chamber 11 is provided with a sputtering gas inlet pipeline, which is, for example, arranged at a position near the target material at the upper part of the deposition chamber 11, and is used to input an inert gas such as argon into the deposition chamber 11. Argon gas is ionized into ions under the action of an external electric field, and bombards the material target source 17 under a high voltage environment, knocking out atoms or molecules of the target material to fly to the surface of the wafer 14, thereby depositing a film. If it is used to deposit an insulating film, in addition to the inert gas used for sputtering, it is also necessary to input reactive gases such as oxygen and nitrogen for the deposition reaction into the deposition chamber 11. The reactive gas and the sputtering gas can be input into the deposition chamber 11 through the same inlet pipeline or through different inlet pipelines. In order to improve the coating performance, the sputtering assembly may include a power source for rotating and / or lifting the target material and / or the magnet, and / or a cooling device, without specific limitation.

[0032] In some examples, a baffle plate may be provided in the deposition chamber 11 to prevent particles from sputtering to the inner wall of the deposition chamber 11, and the baffle plate may extend downward from the periphery of the target along the inner wall of the chamber to the circumferential periphery of the support base. The baffle plate may be made of the same material as the deposition chamber 11, such as aluminum alloy or stainless steel, and the surface may be plated with a corrosion-resistant coating. The baffle plate may be an integrated or split structure. For example, in an example of the present invention, the baffle plate includes an upper baffle plate 15 and a lower baffle plate 16. The upper portion of the upper baffle plate 15 is located at the periphery of the target material and extends downward to the periphery of the wafer 14; the upper portion of the lower baffle plate 16 is connected to the inner wall of the deposition chamber 11 and extends downward to the circumferential periphery of the support base, and the lower portion of the upper baffle plate 15 and the upper portion of the lower baffle plate 16 are partially arranged to seamlessly shield the inner wall of the deposition chamber 11. In some examples, the physical vapor deposition device also includes a shielding ring 18, which is arranged above the support base. For example, in this embodiment, a U-shaped groove is formed in the portion of the lower baffle 16 close to the support base, and the shielding ring 18 is buckled on the lower baffle 16. The through hole in the center of the shielding ring 18 is smaller than the size of the wafer 14, and its annular surface is located directly above the non-coating area at the edge of the wafer 14, which is used to prevent the non-coating area at the edge of the wafer 14 from being coated. In this embodiment, there is a gap between the shielding ring 18 and the wafer 14, that is, it is not pressed on the edge surface of the wafer 14. That is, the front of the wafer 14 in this embodiment is not in direct contact with any process kit. In a further example, a cover ring 19 is also provided between the shielding ring 18 and the target material, and the cover ring 19 is, for example, conical, and its bottom opening is slightly larger than the opening size of the shielding ring 18. The cover ring 19 is pressed on the shielding ring 18, and its bottom end also falls in the U-shaped groove of the lower baffle 16. The cover ring 19 can play a role in converging and guiding the sputtered particles, guiding the sputtered particles to the coating area on the front of the wafer 14. The shielding ring 18 and the cover ring 19 can be made of ceramic materials such as aluminum oxide, aluminum nitride, zirconium oxide, etc., or a composite material in which a ceramic layer is plated on the surface of a metal substrate.

[0033] The support base has a disc-shaped support platform 121 for placing the wafer 14, and may also include a support shaft 122 connected to the bottom of the support platform 121 and extending downward to the outside of the deposition chamber 11. Depending on the process, the support platform 121 can be made of a metal material such as aluminum, or a ceramic material such as aluminum nitride. The support shaft 122 can be electrically connected to a drive motor (not shown) to drive the support platform 121 to rotate and / or lift when necessary. In some examples, a positioning hole 123 and / or a pin lifting hole 124 may be provided in the support platform 121. The positioning hole 123 can be provided in the center of the support platform 121, which can be used as a positioning mark when the wafer 14 enters and exits the cavity to ensure that the position of the wafer 14 does not shift when entering and exiting the cavity.

[0034] A heater may be provided inside the support platform 121. The heater is, for example, a heating resistor wire wound inside the support base. In some examples, a cooling layer may also be provided inside the support base, and the cooling layer may include, for example, a spirally wound water cooling and / or air cooling pipeline to cool the wafer 14 located above the support base when necessary. In addition, an electrode connected to a bias power supply may be provided in the support platform 121. Various source lines including power lines and cooling pipelines may extend from the outside to the support platform 121 via the support shaft 122.

[0035] In the prior art, the upper surface of the support base is usually a plane, and the entire back side of the wafer is directly attached to the support base. In the example provided by the present invention, an annular support ring 13 is arranged above the edge of the support base. The support ring 13 includes a first part 13a and a second part 13b in sequence from the inside to the outside in the radial direction. The opening inside the first part 13a reveals the central area of ​​the support base. A first annular protrusion 131 is arranged on the annular surface of the first part 13a, and the top surface of the protrusion is higher than the horizontal plane of the support base. The back side of the wafer 14, and usually the peripheral area of ​​the back side of the wafer 14, is directly attached to the first annular protrusion 131, so that the wafer 14 is lifted up by the support ring 13 and mounted on the support base. That is, the wafer 14 is not in direct contact with the support base, and the entire front side of the wafer 14 is not attached with a physical barrier and is completely exposed to the deposition atmosphere (for example, no pressure ring is placed on the front surface of the wafer 14, or although a pressure ring is arranged above the front edge of the wafer 14, it is not in direct contact with the surface of the wafer 14). In some examples, an electrostatic adsorption or vacuum adsorption device may be provided on the support base to provide adsorption force to the back of the wafer 14, thereby stabilizing the wafer 14 on the support ring 13. In other examples, while ensuring that the air pressure on the front of the wafer 14 is not less than the air pressure on the back (the pressure on the front of the wafer 14 is not less than the pressure on the back), the wafer 14 may also be placed directly on the support ring 13 without adsorption. The height difference between the top surface of the first annular protrusion 131 and the top surface of the support base (the height difference is also the longitudinal distance between the back of the wafer 14 and the support base) should not be too large or too small. If the distance is too large, the wafer 14 is prone to offset, and if the distance is too small, it will not achieve a good technical effect. In the preferred example provided in this embodiment, the height difference between the two is 0.2mm-2mm, that is, the first annular protrusion 131 is 0.2mm-2mm higher than the top surface of the support base, preferably 0.5mm-1mm. The top surface of the first annular protrusion 131 can be a spherical surface or a rectangular plane, and the radial dimension of the top surface is preferably 0.5mm-1mm. Since the wafer 14 falls directly on the first annular protrusion 131 of the support ring 13, the first annular protrusion 131 abuts against the back edge of the wafer 14 to form a wall, so that the sputtered particles cannot enter the central area of ​​the back of the wafer 14, which can greatly improve the back coating phenomenon of the wafer 14.

[0036] The support ring 13 can be placed directly on the horizontal surface of the support platform 121. The advantage is that the equipment structure is simple, but the disadvantage is that the support ring 13 may be easily offset. In a preferred example, the central area of ​​the support platform 121 is higher than the peripheral area arranged around the central area, that is, the support platform 121 is a structure with a high middle and low edges, thereby forming a step surface at the edge of the support platform 121. In some examples, the support ring 13 can be placed directly on the surface of the peripheral area. For example, an annular groove is provided in the peripheral area, and an annular protrusion adapted to the annular groove is provided on the bottom surface of the support ring 13, so that the support ring 13 is embedded in the support platform 121 to achieve fixation between the two. In other examples, it is also possible to Figure 1 As shown, the device also includes a deposition ring 20, which is mounted on the surface of the peripheral area of ​​the support base and extends downward and outward, and the support ring 13 is mounted on the deposition ring 20. The upper part of the deposition ring 20 is mounted on the step at the edge of the support platform 121, and its side extends downward along the side of the support platform 121. A U-shaped space is formed at its end, which is not only convenient for connection with other kits, but also helps to block sputtering particles. The deposition ring 20 is preferably made of ceramic. In a preferred example, the support ring 13 and the support base have a gap in the lateral direction, that is, the part of the support ring 13 arranged around the support base does not contact the support base, or the sides of the two have a spacing, and the spacing is preferably 0.5mm-1mm. Setting the gap helps to reduce the friction between the two. In some examples, the pressure in the gap can be adjusted to adjust the adsorption force of the region on the wafer 14. For example, in some examples, the gap can be connected to a negative pressure device to provide negative pressure to the wafer 14 so that the wafer 14 is fixed on the support ring 13. In this case, there is no need to set a vacuum adsorption pipeline on the support platform 121, which not only makes the applicable range of the available support base wider, but also prevents the vacuum adsorption pipeline set on the support base from winding during the rotation of the support platform 121 (the gap is fixed, so if negative pressure is provided through the gap, the position of the negative pressure pipeline is fixed). The side of the deposition ring 20 and the side of the support base are also preferably in a non-attached state, for example, there is also a gap of 0.5mm-1mm, which helps to reduce the friction between the deposition ring 20 and the support platform 121.

[0037] There is no strict dividing line between the second part 13b and the first part 13a of the support ring 13. In some examples, the first part 13a and the second part 13b are integrally formed, and the support ring 13 as a whole is preferably made of ceramic materials such as aluminum oxide, aluminum nitride, zirconium oxide, etc., and the surface can be sandblasted or sprayed to increase its surface adsorption force on sputtered particles. In some other examples, the first part 13a and the second part 13b can also be detachably connected, and the two can be made of different materials. For example, in some examples, the first part 13a and the second part 13b are connected by being embedded in each other. The advantage of using a split connection between the two is that different sizes of the second part 13b can be selected according to different sizes of the wafer 14, and when one part is damaged, it can be replaced in time to extend the service life of the spare parts.

[0038] In a preferred example, the periphery of the second portion 13b extends downwardly at an angle to form an inclined slope 133, which can effectively prevent the diffraction of sputtered particles and further prevent the back of the wafer 14 from being coated with a film layer. In the case where the side surface of the wafer 14 is an inclined surface, the formed inclined slope 133 is coplanar with the side surface of the wafer 14, thereby forming a guide surface, which can more smoothly guide the sputtered particles diffused to the periphery of the edge of the wafer 14 to the inclined slope 133 on the periphery of the support ring 13.

[0039] In some examples, such as Figure 4 As shown, an annular clean gas pipeline 21 is provided above the support ring 13, and the clean gas pipeline 21 is specifically located between the support ring 13 and the sputtering device. More specifically, for example, it is located below the aforementioned shielding ring 18. In some examples, the shielding ring 18 and the clean gas pipeline can be combined into one, or the shielding ring 18 also serves as a clean gas pipeline. For example, a plurality of air holes with openings facing obliquely downward are evenly spaced in the shielding ring 18, and an inert clean gas (such as argon or nitrogen) is sprayed obliquely toward the non-coated area at the edge of the wafer 14 and the side of the wafer 14 through these air holes, thereby forming an air curtain at the edge area of ​​the wafer 14. The inert gas can perform edge purge on the wafer 14 to prevent sputtered particles from being deposited on the edge and back of the wafer 14. In addition, the clean gas can also provide pressure on the front edge of the wafer 14, which helps to fix the wafer 14. When the inclined slope 133 of the second part 13b is coplanar with the side of the wafer 14, the sprayed clean gas can be sprayed according to Figure 4 In the direction indicated by the arrow in the figure, the liquid is smoothly discharged downward along the inclined slope 133 of the support ring 13, and the edge of the support base is further purged, which helps to prevent surface coating of the support base and the support ring 13, improve their cleanliness, extend their service life, and reduce the cost of equipment use.

[0040] In some other examples, a gas hole (not shown) connected to an inert gas device may be provided on the side of the first annular protrusion 131, which is used to spray an inert gas toward the periphery of the back of the wafer 14 during the deposition process to prevent sputtered particles from entering the back area of ​​the wafer 14, and also to prevent the back of the wafer 14 from being coated. The sprayed gas should not affect the stability of the wafer 14, for example, the sprayed gas flow rate is within 50sccm. In some examples, the scheme of providing a gas hole on the side of the first annular protrusion 131 and providing an embedded cleaning gas pipeline can be adopted at the same time. In some examples, the edge temperature of the wafer 14 can also be adjusted by adjusting the temperature of the sprayed inert gas. For example, during the coating process, the inert gas temperature can be appropriately increased (for example, higher than the process temperature) to reduce the temperature difference between the edge area and the central area of ​​the wafer 14 and improve the uniformity of the coating. After the coating is completed, the inert gas temperature can be lower to accelerate the cooling of the edge area of ​​the wafer 14 (including the back edge and side of the wafer 14), which helps to improve the stress distribution at the edge of the wafer 14 and improve the coating quality.

[0041] In some examples, the second portion 13 b may also be provided with a vertical portion 134 connected to the bottom of the inclined surface, and the vertical portion 134 extends vertically downward into the groove of the deposition ring 20 to better fix the support ring 13 on the deposition ring 20 .

[0042] In other examples, refer to Figure 5 and Figure 6As shown, the upper surface of the second part 13b has a second annular protrusion 132, and there is a gap between the second annular protrusion 132 and the first annular protrusion 131, and the height of the second annular protrusion 132 is lower than the first annular protrusion 131. Therefore, in the process of the support ring 13 supporting the wafer 14, the second annular protrusion 132 does not contact the wafer 14. The distance between the first annular protrusion 131 and the second annular protrusion 132 is, for example, 5mm-10mm, and the height difference between the two can be controlled to be about 1mm. For example, in a specific example, the height of the first annular protrusion 131 is 2mm, the height of the second annular protrusion 132 is 1mm, and the two are separated by 10mm (the distance between the two refers to the lateral distance between the highest points of the two). In some examples, there can be more than one second annular protrusion 132. For example, a plurality of annular protrusions with successively decreasing heights are arranged at intervals in the direction away from the first annular protrusion 131, and there is no specific limitation. In the case of a second annular protrusion 132 having a height smaller than that of the first annular protrusion 131, the wafer 14 only contacts the first annular protrusion 131, which can reduce the risk of sticking; the sputtered particles can only reach the middle area between the first annular protrusion 131 and the second annular protrusion 132 at most, and cannot pass through the first annular protrusion 131, and due to the further interception of the second annular protrusion 132, the back coating of the wafer 14 can be more effectively reduced. The first annular protrusion 131 and the second annular protrusion 132 can both be spherical protrusions or other shapes, and the connection area between the two can be a horizontal or non-horizontal surface, such as a wavy line surface. Each corner of the first part 13a and the second part 13b is preferably chamfered to avoid local particle accumulation.

[0043] In the case where the sputtered particles are conductive particles, especially conductive metal particles, in some examples, a conductive particle capture device can be provided on the support ring 13, especially on the second portion 13b of the support ring 13. For example, in some examples, the conductive particle capture device includes a conductive material layer provided on the surface of the second annular protrusion 132, for example, the conductive material layer is located on the entire surface of the annular protrusion or only on the outer peripheral surface of the second annular protrusion 132 away from the first annular protrusion 131, and the negative bias voltage applied to the conductive material layer is greater than the negative bias voltage applied to the support base. Therefore, when conductive metal particles enter the area on the back of the wafer 14 that is not blocked by the support ring 13, the conductive particles will be adsorbed and captured by the conductive material layer, which can effectively avoid the back coating of the wafer 14. In view of the fact that the height difference between the second annular protrusion 132 and the first annular protrusion 131 is usually not very large, in order to avoid the top surface of the second annular protrusion 132 from increasing and contacting with the wafer 14 due to the accumulation of conductive particles too quickly, the thickness of the conductive material layer should not be too large, specifically depending on its process and / or the height of the second annular protrusion 132, for example, preferably within 0.5mm. The material of the conductive material layer is preferably not to cause coating contamination, for example, the same as the target material. In some examples, the conductive material layer can be formed on the circumferential surface of the second annular protrusion 132 away from the first annular protrusion 131 by an electroplating process. Or the entire surface of the second annular protrusion 132 is formed with a conductive material layer. In some other examples, the conductive material layer can also be independently arranged on the surface of a partial area of ​​the second part 13b, such as a conductive belt arranged on the corner surface of the second part 13b and / or the surface of the second annular protrusion 132. In the case where the first part 13a and the second part 13b are detachably connected, if metal particles captured on the surface of the second part 13b accumulate, they can be replaced in time.

[0044] In other examples, such as Figure 7 As shown, an annular groove 135 is provided between the first annular protrusion 131 and the second annular protrusion 132, and an air hole connected to a vacuum device is formed on the bottom surface of the annular groove 135 to form a negative pressure environment that can adsorb target particles in the annular groove 135. Therefore, when the target particles enter between the first annular protrusion 131 and the second annular protrusion 132, they will be sucked into the annular groove and then discharged through the air hole, which also helps to reduce the back coating of the wafer 14. At the same time, the negative pressure environment provided helps to better fix the wafer 14 on the support ring 13. And this method is suitable for the capture of charged particles and uncharged particles, and can be applied not only to metal target sputtering, but also to non-metal target sputtering.

[0045] In some examples, the aforementioned conductive material layer and negative pressure adsorption can be used simultaneously to capture the target particles sputtered to the back area of ​​the wafer 14. The wires connecting the conductive material layer and the pipelines required for negative pressure adsorption can be embedded in the grooves on the back of the second part and extend to connect / communicate with the external structure. The conductive particles splashed to the back area of ​​the wafer 14 will first be captured by the conductive material layer of the second annular protrusion 132. If the uncaptured particles escape between the first annular protrusion 131 and the second annular protrusion 132, they will be sucked away. Through dual measures, the back side coating of the wafer can be effectively reduced.

[0046] In summary, the physical vapor deposition equipment provided by the present invention can reduce the back side coating of the wafer through an optimized structural design, and is provided with a support ring including a first part and a second part. The annular surface of the first part is provided with a first annular protrusion for directly contacting the back side of the wafer during the deposition process to mount the wafer on the support base; the second part is connected to the outside of the first part, and the upper surface of the second part is lower than the first part, so that the outermost area of ​​the back side of the wafer is in a suspended state, and the periphery of the second part extends downward to the side of the support base, which can effectively reduce the risk of debris while effectively reducing the back side coating of the wafer, and can avoid adhesion between the wafer and the support base and the process kit, which helps to improve the process yield. The present invention can be used for the deposition of metal films, as well as for the deposition of various types of films such as insulating films and non-metallic conductive films. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0047] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A physical vapor deposition device capable of reducing the backside coating of a wafer, characterized in that: include: A deposition chamber, a support base and a support ring located in the deposition chamber; The support ring is arranged above the circumferential edge of the support base, and includes a first part and a second part. The center of the first part has an opening that exposes the central area of ​​the support base, and the annular surface of the first part is provided with a first annular protrusion that is used to directly contact the back side of the wafer during the deposition process to mount the wafer on the support base; The second part is connected to the outside of the first part, and the upper surface of the second part is lower than the first part, so that the outermost area of ​​the back side of the wafer is suspended, and the periphery of the second part extends downward to the side of the supporting base.

2. The physical vapor deposition device according to claim 1, characterized in that: The height difference between the top surface of the first annular protrusion and the top surface of the support base is 0.2mm-2mm, and the radial dimension of the top surface of the first annular protrusion is 0.5mm-1mm.

3. The physical vapor deposition device according to claim 1, characterized in that: The support ring and the support base have a gap in the lateral direction.

4. The physical vapor deposition device according to claim 1, characterized in that: The periphery of the second portion extends downwardly in an inclined manner to form an inclined slope surface, and the formed inclined slope surface is coplanar with the side surface of the wafer.

5. The physical vapor deposition device according to claim 1, characterized in that: The upper surface of the second part has a second annular protrusion, there is a gap between the second annular protrusion and the first annular protrusion, and the height of the second annular protrusion is lower than that of the first annular protrusion.

6. The physical vapor deposition device according to claim 5, characterized in that: A conductive material layer is provided on the surface of the second annular protrusion, and the negative bias voltage applied to the conductive material layer is greater than the negative bias voltage applied to the support base.

7. The physical vapor deposition device according to claim 5, characterized in that: An annular groove is arranged between the first annular protrusion and the second annular protrusion, and an air hole connected to a vacuum device is formed on the bottom surface of the annular groove to form a negative pressure environment in the annular groove that can adsorb target particles.

8. The physical vapor deposition device according to claim 1, characterized in that: The physical vapor deposition equipment also includes an annular cleaning gas pipeline located above the support ring, and a plurality of gas holes opening obliquely downward are evenly spaced on the cleaning gas pipeline for spraying inert gas toward the side of the wafer in an oblique outward manner.

9. The physical vapor deposition device according to claim 1, characterized in that: The support ring is made of ceramic, the surface of which is sandblasted, and the first part and the second part are integrally formed; or the first part and the second part are detachably connected.

10. The physical vapor deposition device according to any one of claims 1 to 9, characterized in that: The central area of ​​the support base is higher than the peripheral area arranged around the central area. The physical vapor deposition equipment also includes a deposition ring, which is mounted on the surface of the peripheral area of ​​the support base and extends downward and outward. The support ring is mounted on the deposition ring.

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