Plasma vapor deposition equipment

Abstract

The present invention provides a plasma vapor deposition device. The device includes a deposition chamber, a radio frequency device, a wafer carrier and a spray assembly; the wafer carrier has an electrode and a support surface for carrying the wafer; a conductive metal layer is provided at the bottom of the spray assembly, and the spray assembly includes a spray head, the spray head includes a central area and a peripheral area arranged around the central area, the peripheral area is correspondingly arranged above the edge of the wafer, and the peripheral area is provided with a spray hole, and the spray hole is used to supply a reaction gas flow to the non-device area of ​​the wafer including the side, the central area of ​​the spray head is correspondingly arranged above the center of the wafer, and the central area protrudes toward the wafer direction compared with the peripheral area, so that the straight-line distance between the central area and the wafer is smaller than the straight-line distance between the peripheral area and the wafer, and the central area does not supply the reaction gas flow during the process of supplying the reaction gas flow to the peripheral area. The present invention can perform precise thin film deposition on the edge area of ​​the wafer to avoid subsequent process defects.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuit manufacturing equipment, and in particular to a plasma vapor deposition equipment. Background Art

[0002] With the continuous improvement of semiconductor manufacturing technology and the continuous compression of costs, the control of the ineffective area of ​​the wafer (that is, the area on the surface of the wafer where devices cannot be manufactured) has become increasingly strict, so the ineffective area of ​​the wafer edge is getting smaller and smaller, and the yield problems caused by the edge and side of the wafer (such problems are often called edge defects or bevel defects) are also increasing. For example, due to the presence of contaminants on the edge and / or side of the wafer, deep pits (pits) may be generated during the etching process, or the edge of the wafer may be over-polished during the grinding process, or contaminants may migrate during the deposition process (such as the migration of metal ions such as nickel and platinum). These defects may cause electrical failure of the device, and in severe cases, may lead to scrapping of the wafer.

[0003] To solve such problems, a commonly used method in the prior art is to form a protective film layer on the edge of the wafer. For example, an oxide film can be formed on the edge of the wafer as a sacrificial layer for CMP to avoid excessive polishing of the wafer edge, or pollutants can be encapsulated by the oxide film to prevent migration from the bevel to the device area, and to prevent the formation of silicone rubber on the bevel. However, due to the limitations of existing equipment, the current method of forming a protective film on the edge of the wafer generally uses equipment such as furnace tubes to form a film on the entire surface of the wafer, and then removes the protective film in the wafer device area by cleaning. However, this method not only reduces the output rate due to the cumbersome process, but also may cause device damage during the film formation and cleaning process in the wafer device area, which will also lead to a decrease in production yield and an increase in production costs.

[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 plasma vapor deposition device to solve the problem in the prior art that a protective film is formed on the entire surface of a wafer using equipment such as a furnace tube, and then the protective film in the device area of ​​the wafer is removed through processes such as cleaning. The method of forming a protective film on the edge and side of the wafer has low production efficiency and / or causes device damage.

[0006] To achieve the above-mentioned purpose and other related purposes, the present invention provides a plasma vapor deposition device, which includes a deposition chamber, a radio frequency device, a wafer supporting device located in the deposition chamber, and a spray assembly located on the upper part of the deposition chamber; the wafer supporting device has an electrode and a supporting surface for supporting the wafer; a conductive metal layer electrically connected to the radio frequency device is arranged at the bottom of the spray assembly, and the spray assembly includes a spray head, the spray head includes a central area and a peripheral area arranged around the central area, the peripheral area is correspondingly arranged above the edge of the wafer, and the peripheral area is provided with spray holes, the spray holes are used to supply a reaction gas flow to a non-device area of ​​the wafer including the side, the central area of ​​the spray head is correspondingly arranged above the center of the wafer, and the central area protrudes toward the wafer compared with the peripheral area, so that the straight-line distance between the central area and the wafer is smaller than the straight-line distance between the peripheral area and the wafer, and the central area does not supply the reaction gas flow during the process of supplying the reaction gas flow to the peripheral area.

[0007] In an optional solution, no spray hole is provided in the central area of ​​the spray head.

[0008] In another alternative, the spray holes in the central area are closed during the process of supplying the reaction gas flow in the peripheral area.

[0009] Optionally, a straight-line distance between the central area and the wafer is less than 2 mm and greater than or equal to 0.5 mm.

[0010] Optionally, the plasma vapor deposition equipment further comprises a gas cabinet arranged on the upper part of the spray assembly, and a baffle located between the gas cabinet and the spray head, wherein the edge of the baffle is provided with air holes connecting the gas cabinet and the spray holes in the peripheral area of ​​the spray head.

[0011] Optionally, the spray holes in the peripheral area of ​​the shower head include a first spray hole and a second spray hole, the opening of the first spray hole is vertically downward, and the opening of the second spray hole is inclined toward the non-device area of ​​the wafer.

[0012] Optionally, the wafer supporting device includes a center ring and a peripheral ring arranged around the center ring, the diameter of the center ring is smaller than the diameter of the wafer, and the center ring protrudes toward the shower head.

[0013] Optionally, the protruding height of the central circle is not greater than 3 mm, and the diameter of the outer circle is 0.5 mm-2 mm.

[0014] Optionally, the carrying surface of the wafer carrying device is provided with vacuum adsorption holes.

[0015] Optionally, the wafer carrying device includes a heater and an ejector pin assembly, and the ejector pin assembly includes a plurality of ejector pins that are inserted into the heater and can be lifted up and down.

[0016] Optionally, the central area of ​​the shower head is height-adjustable.

[0017] As described above, the plasma vapor deposition equipment provided by the present invention has the following beneficial effects: the plasma vapor deposition equipment provided by the present invention reduces or even avoids the gas inflow into the central area of ​​the wafer during the vapor deposition process through an optimized structural design, and controls the formation of the RF electric field by controlling the straight-line distance (gap) between the central area of ​​the shower head and the central area of ​​the wafer, thereby effectively and accurately controlling the thin film deposition area, thereby achieving accurate film formation in the non-device area at the edge of the wafer, which helps to reduce or even avoid the defects of subsequent processes and helps to improve production yield. At the same time, the plasma deposition equipment provided by the present invention helps to reduce the damage to the wafer during the deposition process compared to the existing method of depositing at the edge of the wafer, and can greatly improve the deposition efficiency and improve the output rate of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Shown is a schematic diagram of the cross-sectional structure of the plasma vapor deposition equipment provided by the present invention.

[0019] Figure 2 Shown is a schematic diagram of the cross-sectional structure of a wafer supporting device of the plasma vapor deposition equipment provided by the present invention.

[0020] Figure 3 Shown is a schematic diagram of the cross-sectional structure of a shower head of the plasma vapor deposition equipment provided by the present invention. DETAILED DESCRIPTION

[0021] 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.

[0022] 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.

[0023] In the context of the present invention, a structure described as a first feature being "above" a second feature may include embodiments where the first and second features are formed in direct contact, and may also include embodiments where additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0024] 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.

[0025] like Figures 1 to 3 As shown, the present invention provides a plasma vapor deposition device, which includes a deposition chamber 11, a radio frequency device, a wafer carrier 13 located in the deposition chamber 11, and a spray assembly located on the upper part of the deposition chamber 11.

[0026] The deposition chamber 11 accommodates the deposition assembly and provides a deposition space. The side wall of the deposition chamber 11 may be provided with a gate valve 111 for the wafer 15 to enter and exit, and an exhaust port (not shown) may be provided at the bottom or the lower part of the side wall, and the exhaust port is connected to an exhaust pump (not shown) to discharge the reaction gas residues and reaction by-products in the chamber in time as needed, and the inside of the deposition chamber 11 may be maintained at a desired vacuum degree as needed. For example, if it is PECVD, the vacuum degree in the deposition chamber 11 needs to be controlled at 10^-7 Torr to 10^-3 Torr during the deposition process to ensure that the gas molecules have sufficient degrees of freedom to participate in the chemical reaction. Depending on the substrate to be deposited, the deposition chamber 11 may have different sizes and shapes. In this embodiment, the substrate to be deposited is a generally circular wafer 15, so the deposition chamber 11 is generally cylindrical. The deposition chamber 11 can be made of a metal material such as stainless steel, and the inner wall of the chamber may be provided with an anti-corrosion coating such as aluminum oxide, and / or a baffle 17 (not shown) may be provided on the inner wall of the chamber to prevent contamination of the chamber. During the deposition process, the deposition chamber 11 may be grounded.

[0027] The wafer carrier 13 has an electrode and a supporting surface for carrying the wafer 15. For example, the wafer carrier 13 is in the shape of a disk as a whole, and the surface of the disk is the wafer supporting surface, and its supporting surface can be consistent with the size of the wafer 15, that is, the wafer supporting surface can be a flat surface as a whole. However, in a preferred example provided by the present invention, the wafer carrier 13 includes a central circle 131 and an outer circle 132 arranged around the central circle 131, the diameter of the central circle 131 is smaller than the diameter of the wafer 15, and the central circle 131 protrudes toward the shower head 14. That is, in this embodiment, the central circle 131 and the outer circle 132 of the wafer carrier 13 have a height difference d1, thereby forming a step at the junction of the two. The central circle 131 corresponds to the center of the wafer 15, or the device area of ​​the wafer 15 (that is, the effective area on the wafer 15 for manufacturing devices), and the outer circle 132 corresponds to the non-device area at the edge of the wafer 15 (that is, the area at the edge of the wafer 15 where devices are not manufactured). During the deposition process, the edge area of ​​the wafer 15 is not in direct contact with the bearing surface of the wafer carrier 13 and is in a suspended state. This helps the reaction gas flow during the deposition process to diffuse to the unsupported area on the side and back of the wafer 15, and can effectively prevent the thin film deposited on the surface of the wafer 15 from diffusing to the surface of the wafer carrier 13. In some examples, a guide ring (not shown) may be provided on the periphery of the side of the wafer 15, which extends from the inner wall of the cavity to the periphery of the side of the wafer 15 and is spaced from the edge of the wafer 15 to guide the reaction gas flow to flow through the side of the wafer 15. The center ring 131 of the wafer carrier 13 protrudes toward the shower head 14, which can reduce the linear distance between the center area 141 of the wafer 15 and the shower head 14, and helps to reduce or even avoid the deposition of thin films in the center area 141 of the wafer 15. The protrusion height of the center ring 131 and the size of the outer ring 132 can be determined as needed, for example, according to the size of the non-device area of ​​the wafer 15, and the adaptation of other components in the device needs to be comprehensively considered. The inventors have found through numerous experiments that the protrusion height d1 of the center ring 131 is not greater than 3mm, for example 1mm-2mm, and the diameter of the outer ring 132 is preferably 0.5mm-2mm. The overall structure of the wafer carrier 13 is preferably integrally formed, that is, the center ring 131 and the outer ring 132 are integrally formed.

[0028] During the vapor deposition process, the wafer 15 can be fixed on the surface of the wafer carrier 13 in any suitable manner without blocking the deposition area. For example, a pressing ring can be set to press on the device area of ​​the wafer 15 to fix the wafer 15 on the wafer carrier 13. In a preferred example provided by the present invention, Figure 2As shown, the wafer 15 is fixed by vacuum adsorption, so the bearing surface of the wafer carrier 13 is provided with a vacuum adsorption hole 133. The opening surface of the vacuum adsorption hole 133 may be flush with the bearing surface, or slightly lower than the bearing surface. For example, in one example, the bearing surface of the wafer carrier 13 is provided with a plurality of annular grooves spaced outward from its center, and the vacuum adsorption holes 133 are evenly spaced in the annular grooves. Different vacuum adsorption holes 133 can be connected to the same or different vacuum pumps through vacuum pipelines to provide adsorption force on the wafer 15 to prevent the wafer 15 from shifting during the deposition process. For example, in a further example, the vacuum adsorption holes 133 in the same annular groove are connected to the same vacuum pump, while the vacuum adsorption holes 133 in different annular grooves are connected to different vacuum pumps. This can independently adjust the power of the vacuum pumps in different areas, thereby providing different adsorption forces to different areas of the wafer 15 according to the different warping conditions on the surface of the wafer 15, which can strengthen the fixation of the wafer 15 and improve the warping of the wafer 15. In particular, the vacuum adsorption holes 133 corresponding to the device area of ​​the wafer 15 and the vacuum adsorption holes 133 corresponding to the non-device area of ​​the wafer 15 can be connected to different vacuum pumps, which helps to improve the edge warping of the wafer 15.

[0029] In some examples, the wafer carrier 13 includes a heater for heating the wafer 15. For example, in some examples, the wafer carrier 13 is made of metal as a whole, such as aluminum, and a plurality of coils of heating resistor wire are arranged inside the wafer carrier 13, which can be heated after being powered on. In the case where the wafer carrier 13 is made of metal material, the wafer carrier 13 not only serves as a heater, but also acts as a lower electrode as a whole, which can be grounded or connected to a biased RF device during the deposition process. A water cooling pipeline can also be provided in the wafer carrier 13 to cool the wafer 15 when necessary. In order to accurately control the temperature, a temperature measuring device such as a thermocouple (not shown) can also be provided in the wafer carrier 13.

[0030] In some examples, the wafer carrier 13 also includes an ejector pin assembly, which includes a plurality of ejector pins 134 that are inserted into the heater and can be raised and lowered. The ejector pin 134 can be made of, for example, ceramic, silicon carbide, or the like, and its surface in contact with the wafer 15 can be a circular surface or a conical surface. The ejector pin 134 can be raised and lowered pneumatically, for example, a gas pipeline is provided directly below the ejector pin 134, and the ejector pin 134 is raised or lowered by changing the gas flow in the gas pipeline. The ejector pin 134 can also be driven by a lifting structure such as a cylinder to drive the ejector pin 134 to rise and fall, and there is no limitation to this.

[0031] In another example, the wafer carrier 13 may also be composed of a plurality of structural layers, that is, it may be a split structure. For example, the wafer carrier 13 at least includes a metal material layer located at the upper portion and used as a lower electrode, and a temperature regulating layer having a heating pipeline and / or a cooling pipeline, and may also include a magnetic field regulating layer, which is not limited.

[0032] In some examples, the plasma deposition apparatus further includes a support shaft (not shown) disposed at the bottom of the wafer carrier 13, and the support shaft can extend from the inside of the deposition chamber 11 to the outside. Pipelines such as a power line 135, a vacuum line 136, and a cooling water line 137 can be disposed in the support shaft and extend upward to connect / communicate with corresponding structures on the wafer carrier 13. For example, the power line 135 can extend to be electrically connected to the lower electrode. The support shaft can be connected to a rotating and / or lifting structure (e.g., a cylinder) to drive the wafer 15 to rotate and / or lift when necessary.

[0033] The radio frequency device at least includes a radio frequency power supply 12, which is used to provide a high-frequency electromagnetic field to excite plasma. That is, the reaction gas (such as silane, ammonia, etc.) is ionized into positive and negative ions and free radicals. In this embodiment, the radio frequency of the radio frequency power supply 12 is 13.56 MHz, which can effectively activate the reaction gas and generate highly active free radicals.

[0034] The bottom of the spray assembly has a conductive metal layer electrically connected to the radio frequency device. That is, the spray assembly includes a conductive structure, and in addition to being used to supply the reaction gas flow into the deposition chamber 11, the spray assembly also assumes the function of the upper electrode. In this embodiment, the spray assembly and the wafer carrier 13 form a parallel electrode structure, and when a high-voltage power supply is applied to the upper and lower electrodes, a high-voltage electric field is generated between the upper and lower electrodes. When the reaction gas enters the deposition chamber 11 through the spray assembly and enters between the upper and lower electrodes, plasma is generated due to glow discharge, thereby decomposing the reaction gas molecules into active groups, which react chemically with the surface to be deposited of the wafer 15 to form a thin film in the area to be deposited.

[0035] Specifically, the spray assembly includes a spray head 14. The structure of the spray head 14 can be referred to Figure 3As shown, it includes a central area 141 and a peripheral area 142 arranged around the central area 141. In order to facilitate fixing the shower head 14 in the deposition chamber 11, the shower head 14 can also include a support area 143 connected to the periphery of the peripheral area 142, the support area 143 extends outward, and a step is formed between the support area 143 and the peripheral area 142, so that the shower head 14 can be mounted on the side wall of the deposition chamber 11 through the support area 143 (or the support area 143 can also be considered as a part of the peripheral area 142). In a preferred example, the shower head 14 is an integrally formed structure, and the overall material is a conductive metal, which is machined. For example, the shower head 14 is made of aluminum. The shower head 14 made of conductive metal as a whole serves as an upper electrode. In another example, the shower head 14 may also be a split structure, for example, the central area 141 and the peripheral area 142 of the shower head 14 are connected by threads, for example, the through hole in the center of the peripheral area 142 is provided with an internal thread, and the central area 141 of the shower head 14 is cylindrical and has an external thread, and the central area 141 is threadedly embedded in the through hole in the center of the peripheral area 142. With this structure, the height of the central area 141 of the shower head 14 can be changed by adjusting the thread, especially adjusting the linear distance between it and the wafer 15. In some other examples, the central area 141 and the peripheral area 142 of the shower head 14 can also be flexibly connected, for example, connected by a connector similar to a bellows, which can also achieve the effect of adjustable linear distance between the central area 141 of the shower head 14 and the wafer 15, so as to more flexibly adjust the electric field between the upper and lower electrodes. The distance between the central area of ​​the shower head and the wafer can be adjusted by adjusting the height of the central area of ​​the shower head without adjusting the overall height of the shower head, without changing the position of other components in the cavity, which can greatly simplify the installation and adjustment of the equipment.

[0036] The peripheral area 142 of the shower head 14 is correspondingly arranged above the edge of the wafer 15, and the peripheral area 142 is provided with a spray hole, which is used to supply a reactive gas flow toward the non-device area including the side of the wafer 15. The central area 141 of the shower head 14 is correspondingly arranged above the center of the wafer 15, and the central area 141 protrudes toward the wafer 15 compared with the peripheral area 142, so that the straight-line distance between the central area 141 and the wafer 15 is smaller than the straight-line distance between the peripheral area 142 and the wafer 15, and the central area 141 does not supply a reactive gas flow during the process of supplying the reactive gas flow to the peripheral area 142. That is, a height difference d2 is formed between the central area 141 and the peripheral area 142 of the shower head 14. It is found through experiments that the height difference is preferably >5mm, but preferably controlled within 10mm. It should be noted that if the peripheral area 142 includes the support area 143 as described above, the height difference d2 between the peripheral area 142 and the central area 141 refers to the longitudinal distance between the bottom of the two.

[0037] The reason why the central area 141 of the showerhead 14 is arranged closer to the wafer 15 than the peripheral area 142 is that the generation of the RF (radio frequency) electric field is closely related to the electrode spacing. In an RF system, when the electrode spacing is small, a significant RF electric field is usually not directly generated for the following reasons:

[0038] 1. Relationship between electric field strength and electrode spacing

[0039] According to radio frequency theory, the strength of the RF electric field is inversely proportional to the electrode spacing. When the electrode spacing is small, the electric field strength increases significantly, but this increase may not be sufficient to maintain a stable RF electric field. For example, in some cases, too small an electrode spacing may cause the electric field to be too concentrated, thereby inducing other physical effects (such as dielectric breakdown or arc discharge) instead of a stable RF electric field.

[0040] 2. RF Cavity Design and Resonance Frequency

[0041] In an RF cavity, the formation of an electric field depends on the geometry, size, and resonant frequency of the cavity. If the electrode spacing is too small, the physical requirements of the resonant cavity may not be met, resulting in the inability to form an effective RF electric field. For example, in the thin lens model, when the electrode spacing is less than a certain value, this region is considered an "RF gap" and its electric field strength is relatively low, which is not enough to significantly accelerate particles.

[0042] 3. Inhomogeneity of electric field distribution

[0043] When the distance between electrodes is small, the electric field distribution may become very non-uniform. This non-uniformity causes electrons to be strongly repelled away from the electrode surface. For example, in a gas trap, when the distance between ions and electrodes is large, the ions are repelled away from the wall. Similarly, when the distance between electrodes is too small, the electric field may not be uniformly distributed, thereby weakening the effect of the RF electric field.

[0044] 4. Reduced energy transmission efficiency

[0045] In RF systems, energy transmission efficiency is closely related to the electrode spacing. If the spacing is too small, the energy may be concentrated in a local area and cannot be effectively transmitted to the target area. For example, in non-invasive bipolar RF treatment, when the RF energy propagates along the electrode path, if the spacing is too small, it may cause uneven energy distribution or insufficient thermal effect.

[0046] 5. Influence of dielectric properties

[0047] In some cases, the dielectric constant and conductivity of the medium can also affect the formation of the RF electric field. For example, in a non-insulated tip design, the dielectric properties of the medium may limit the formation of the electric field. In addition, the behavior of free carriers (such as electrons and ions) in the medium can also be affected by the electrode spacing.

[0048] In summary, when the distance between the upper and lower electrodes is small, a stable RF electric field is usually not directly generated due to insufficient electric field strength, uneven distribution, reduced energy transmission efficiency, and the influence of dielectric properties. Instead, this situation may lead to other physical effects (such as dielectric breakdown, arc discharge, or energy concentration). In the present embodiment, the reactive gas flow is only supplied by the peripheral region 142 of the shower head 14, and the reactive gas flow is not supplied to the central region 141 of the shower head 14 during the process of supplying the reactive gas flow to the peripheral region 142, so that the reactive gas flow is directionally supplied to the edge and side of the wafer 15, which are non-device regions. In addition, the central region 141 of the shower head 14 is protruded toward the wafer 15 compared with the peripheral region 142, so that the straight-line distance between the central region 141 and the wafer 15 is smaller than the straight-line distance between the peripheral region 142 and the wafer 15. Therefore, even if a small amount of gas flow is diffused to the device region of the wafer 15, it is difficult to generate effective plasma due to the insufficient electric field strength in the corresponding region and the low energy transmission efficiency. Therefore, the active radicals required for thin film deposition cannot be generated, and no film is formed in the central region 141 of the wafer 15. Thus, the purpose of directional film formation at the edge and side of the wafer 15 is achieved, good edge protection can be formed for the wafer 15, and the defects of subsequent processes can be effectively reduced or even avoided, such as avoiding deep pit defects in the subsequent etching process, avoiding excessive grinding and metal contamination, etc., which helps to improve the production yield. Using the plasma vapor deposition equipment provided by the present invention to perform edge deposition on the wafer 15 can effectively improve production efficiency and reduce production costs.

[0049] As mentioned above, when the distance between the upper and lower electrodes is too small, the electric field distribution between the two electrodes may become very uneven, so theoretically the smaller the distance between the upper and lower electrodes, the better. The inventors have found through extensive research that when the linear distance between the central area 141 of the shower head 14 and the wafer 15 is less than 3 mm, the inhibitory effect on plasma generation due to electric field unevenness and other reasons will gradually appear. More preferably, the distance is less than 2 mm, and considering the convenience of installation of equipment components, the distance is preferably greater than or equal to 0.5 mm.

[0050] In order to prevent the central region 141 of the shower head 14 from supplying reactive gas flow during the deposition process, in some examples, the central region 141 of the shower head 14 is not provided with a spray hole. The shower head 14 with such a structure can be used exclusively for edge deposition of the wafer 15 .

[0051] In some other examples, the central area 141 is provided with spray holes, but the spray holes in the central area 141 are closed during the process of supplying reactive gas flow in the peripheral area 142. For example, a movable shield may be provided on the upper surface of the central area 141 of the corresponding shower head 14 to cover the spray holes in this area when edge deposition is performed on the wafer 15.

[0052] As mentioned above, when the shower head 14 is made of conductive metal as a whole, the shower head 14 also acts as an upper electrode. In another example, it can also be a local area of ​​the shower head 14, for example, the bottom surface of the shower head 14 is a conductive metal layer such as aluminum. Or in other examples, a lower electrode layer independent of the shower head 14 can be provided on the bottom surface of the shower head 14. That is, the lower electrode layer can be a part of the shower head 14, or a structure independent of the shower head 14, and there is no limitation on this. The spray hole can be a cylindrical hole or a conical hole, and an anti-corrosion coating can be formed on the inner surface of the spray hole, for example, a ceramic material layer such as aluminum oxide and yttrium oxide is formed. The spray holes are preferably evenly spaced in the peripheral area 142 of the shower head 14, and the distribution of the spray holes can also be adjusted according to different needs, for example, no spray holes are provided near the area corresponding to the edge notch of the wafer 15, and the aperture size can be determined as needed, for example, 1mm-2mm. In some examples, different spray holes may have substantially the same hole diameter.

[0053] Since the side of the wafer 15 is usually a bevel, in some other examples, in order to more accurately supply the reaction gas flow to the bevel of the wafer 15, the spray holes in the peripheral area 142 of the spray head 14 include a first spray hole 144a and a second spray hole 144b. The opening of the first spray hole 144a is vertically downward, and it is toward the non-device area of ​​the edge of the wafer 15. The opening of the second spray hole 144b is inclined toward the non-device area of ​​the wafer 15, especially toward the inclined side of the wafer 15. The inclination angle of the second spray hole 144b can be substantially the same as the slope of the bevel of the wafer 15. The first spray hole 144a and the second spray hole 144b can be interconnected, or not interconnected. The first spray hole 144a and the second spray hole 144b can be evenly spaced and distributed on different circumferential surfaces, or unevenly distributed (preferably evenly distributed).

[0054] In some examples, the spray hole may be a cavity formed in the spray head 14 by machining or the like. In this structure, the bottom surface of the spray hole is usually flush with the bottom surface of the spray head 14, and the vertical height of the spray hole cannot be adjusted.

[0055] In some other examples, the spray hole may have a solid structure, and its vertical height is adjustable. For example, the spray hole may be a pipe such as a ceramic tube embedded in the opening of the spray head 14. Under this structure, the spray hole may protrude from the bottom surface of the spray area, and pipes of different lengths may be selected according to different needs (for example, the smaller the edge area of ​​the wafer 15, the more suitable the longer the spray hole). Thus, the distance between the spray hole and the deposition area can be adjusted to achieve more accurate airflow supply, thereby more accurate film formation, which helps to improve production yield. At the same time, under this structure, a second spray hole 144b with different slopes can be used according to the slope of the side of the wafer 15.

[0056] In order to facilitate the arrangement of components including gas pipelines, in one example, the plasma vapor deposition equipment further includes a gas cabinet 16 disposed on the upper part of the spray assembly. The gas cabinet 16 includes components such as reaction gas pipelines and valves for controlling the on and off of the gas, and the radio frequency device can also be coupled to the gas cabinet 16. In some examples, the gas cabinet 16 also includes an RPS supply component. RPS (Remote Plasma Source) technology can be used to effectively clean the deposition chamber 11 in plasma vapor deposition, especially plasma enhanced chemical vapor deposition (PECVD). It uses plasma generated by radio frequency (RF) to dissociate the cleaning gas (such as NF3, CF4, etc.) to generate highly active fluoride or fluorocarbon free radicals. These free radicals react with the residues on the inner wall of the deposition chamber 11 to form gaseous products, which are then discharged from the chamber through the exhaust system, thereby achieving the cleaning of the chamber. In this embodiment, the RPS system is integrated into the gas cabinet 16 located outside the deposition space, and the cleaning gas is activated by the radio frequency power supply 12 to generate plasma in the deposition chamber 11. The active free radicals in the plasma can effectively and efficiently remove the residues on the chamber wall, including SiO2 film particles and other difficult-to-remove contaminants, which can not only improve the cleaning efficiency of the chamber, but also reduce the cleaning downtime, thereby improving the overall production efficiency of the equipment, and also avoid the problem of damage to the chamber material in traditional cleaning methods. At the same time, using RPS technology for cleaning can reduce dependence on traditional cleaning chemicals (such as wet cleaning agents), while reducing energy consumption and waste emissions during the cleaning process.

[0057] In some examples, the plasma vapor deposition apparatus further includes a baffle 17 located between the gas cabinet 16 and the shower head 14, and the edge of the baffle 17 is provided with air holes 171 that communicate with the gas cabinet 16 and the spray holes in the peripheral area 142 of the shower head 14. The baffle 17 can be attached to the upper surface of the shower head 14, and its central area corresponds to the central area 141 of the shower head 14, and the air holes 171 on the periphery of the baffle 17 are connected with the air holes 171 in the peripheral area 142 of the shower head 14. In some examples, when the spray holes of the shower head 14 are connected to each other, the air holes 171 of the baffle 17 can correspond to and communicate with the first spray hole 144a of the shower head 14. In some examples, the periphery of the baffle 17 can be provided with annular air grooves, and these air grooves are connected with the spray holes of the shower head 14 through the air holes 171. The baffle 17 can make the process gas mix better before flowing into the deposition chamber 11, thereby helping to improve the density, uniformity and adhesion of the film and the performance of the final product. The baffle 17 can be made of insulating materials such as ceramics and quartz, or the same material as the shower head 14, such as aluminum.

[0058] The plasma vapor deposition device provided in this embodiment is generally applicable to chemical vapor deposition, and more specifically, applicable to plasma enhanced chemical vapor deposition. Other structures not mentioned here can refer to existing similar devices, and are not strictly limited thereto.

[0059] In summary, the plasma vapor deposition equipment provided by the present invention reduces or even avoids the gas inflow into the central area of ​​the wafer during the vapor deposition process through an optimized structural design, and controls the formation of the RF electric field by controlling the straight-line distance (gap) between the central area of ​​the shower head and the central area of ​​the wafer, thereby effectively and accurately controlling the thin film deposition area, thereby achieving accurate film formation in the non-device area at the edge of the wafer, which helps to reduce or even avoid the defects of subsequent processes and helps to improve production yield. At the same time, the plasma deposition equipment provided by the present invention helps to reduce the damage to the wafer during the deposition process compared to the existing method of depositing at the edge of the wafer, and can greatly improve the deposition efficiency and improve the output rate of the equipment.

[0060] Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0061] 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 plasma vapor deposition device, characterized in that: The plasma vapor deposition equipment comprises a deposition chamber, a radio frequency device, a wafer carrying device located in the deposition chamber, and a spray assembly located on the upper part of the deposition chamber; the wafer carrying device has an electrode and a supporting surface for carrying the wafer; a conductive metal layer electrically connected to the radio frequency device is arranged at the bottom of the spray assembly; the spray assembly comprises a spray head, the spray head comprises a central area and a peripheral area arranged around the central area, the peripheral area is correspondingly arranged above the edge of the wafer, the peripheral area is provided with a spray hole, the spray hole is used to supply a reaction gas flow to a non-device area of ​​the wafer including the side, the central area of ​​the spray head is correspondingly arranged above the center of the wafer, and the central area protrudes toward the wafer compared with the peripheral area, so that the linear distance between the central area and the wafer is smaller than the linear distance between the peripheral area and the wafer, and the central area does not supply the reaction gas flow during the process of supplying the reaction gas flow to the peripheral area; wherein the central area and the peripheral area of ​​the spray head are flexibly connected by a bellows, so that the linear distance between the central area of ​​the spray head and the wafer is adjustable; the vertical height of the spray hole is adjustable.

2. The plasma vapor deposition device according to claim 1, characterized in that: The central area of ​​the shower head is not provided with a shower hole; or the shower holes in the central area are closed during the process of supplying the reaction gas flow in the peripheral area.

3. The plasma vapor deposition equipment according to claim 1, characterized in that: The straight-line distance between the central area and the wafer is less than 2 mm and greater than or equal to 0.5 mm.

4. The plasma vapor deposition apparatus according to claim 1, characterized in that: The plasma vapor deposition equipment also includes a gas cabinet arranged on the upper part of the spray assembly, and a baffle located between the gas cabinet and the spray head, and the edge of the baffle is provided with air holes connecting the gas cabinet and the spray holes in the peripheral area of ​​the spray head.

5. The plasma vapor deposition equipment according to claim 1, characterized in that: The spray holes in the peripheral area of ​​the shower head include a first spray hole and a second spray hole. The opening of the first spray hole is vertically downward, and the opening of the second spray hole is inclined toward the non-device area of ​​the wafer.

6. The plasma vapor deposition equipment according to claim 1, characterized in that: The wafer carrying device comprises a central ring and an outer ring arranged around the central ring. The diameter of the central ring is smaller than the diameter of the wafer, and the central ring protrudes toward the shower head.

7. The plasma vapor deposition equipment according to claim 6, characterized in that: The protruding height of the central circle is no more than 3 mm, and the diameter of the outer circle is 0.5 mm-2 mm.

8. The plasma vapor deposition equipment according to claim 1, characterized in that: The carrying surface of the wafer carrying device is provided with vacuum adsorption holes.

9. The plasma vapor deposition apparatus according to claim 1, characterized in that: The wafer carrying device comprises a heater and an ejector pin assembly. The ejector pin assembly comprises a plurality of ejector pins which are inserted into the heater and can be lifted up and down.

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