Radio frequency current transmission structure, semiconductor process equipment, radio frequency current detection method and machine detection method

Abstract

The invention discloses a radio frequency current transmission structure, semiconductor process equipment, a radio frequency current detection method and a machine table detection method, and relates to the field of semiconductors. A radio frequency current transmission structure is applied to semiconductor process equipment and comprises a feed-in piece, a dielectric layer, a first backflow layer, a magnetic material layer and a second backflow layer which are sequentially arranged from inside to outside. One end of the feed-in piece is used for receiving radio frequency current, the other end of the feed-in piece is used for being connected to a radio frequency receiving piece, one end of the first backflow layer and one end of the second backflow layer are used for being connected to a grounding piece, and the radio frequency receiving piece is connected with the grounding piece. The other end of the first backflow layer and the other end of the second backflow layer are respectively used for leading out radio frequency current, and the current in the first backflow layer is larger than that in the second backflow layer. The problems that an existing radio frequency energy transmission loop is tedious in adjustment, poor in adjustment and compensation effect and the like can be solved.

Description

Technical Field

[0001] This application belongs to the field of semiconductor technology, specifically relating to a radio frequency current transmission structure, semiconductor process equipment, radio frequency current detection method, and equipment detection method. Background Technology

[0002] In processes such as plasma etching, radio frequency (RF) energy is used to generate plasma for wafer processing, accelerating positive ions in the plasma to a certain velocity and acting on the wafer to enhance the processing and thus improve yield. The RF energy is transmitted through a tuning network and RF transmission loop to the energy coupling components of the semiconductor processing equipment. The RF energy transmission loop characterizes the path transmission characteristics of the RF energy current, directly affecting the uniformity of the surface chemical composition and the uniformity of particle energy reaching the wafer surface simultaneously during wafer processing.

[0003] With the development of semiconductor manufacturing processes, the requirements for uniformity in semiconductor processing are becoming increasingly stringent. However, semiconductor processing equipment has numerous internal components with high integration, making it impossible to guarantee absolute circumferential and radial uniformity in the radio frequency energy transmission circuit.

[0004] In related technologies, to improve the uniformity of the radio frequency energy transmission loop in the circumference or radial direction, some structures are adjusted and compensated to change the transmission path of the radio frequency current. However, when adjusting the structure, other related structures also need to be adjusted, which makes the adjustment process cumbersome. Furthermore, since the influence of each structure on the process effect varies, it is difficult to achieve the expected adjustment and compensation effect. Summary of the Invention

[0005] The purpose of this application is to provide a radio frequency current transmission structure, semiconductor process equipment, radio frequency current detection method, and machine detection method, which can solve the problems of cumbersome adjustment and poor adjustment compensation effect of the current radio frequency energy transmission circuit.

[0006] To solve the above-mentioned technical problems, this application is implemented as follows: This application provides a radio frequency current transmission structure for use in semiconductor process equipment. The radio frequency current transmission structure includes, from the inside out, a feed element, a dielectric layer, a first return layer, a magnetic material layer, and a second return layer. One end of the feeder is used to receive radio frequency current, and the other end of the feeder is used to connect to the radio frequency receiver of the semiconductor process equipment. One end of the first return layer and the second return layer are respectively used to connect to the grounding device of the semiconductor process equipment. The radio frequency receiver is connected to the grounding device. The other end of the first return layer and the second return layer are respectively used to lead out radio frequency current, and the current in the first return layer is greater than the current in the second return layer.

[0007] This application embodiment also provides a semiconductor process apparatus, including: a cavity, an upper electrode device, and an upper electrode radio frequency source device. The upper electrode device includes a grounding protective cover, a coil, and the aforementioned radio frequency current transmission structure. The grounding protective cover serves as the grounding element and is disposed on the top of the cavity. The coil serves as the radio frequency receiver and is disposed inside the grounding protective cover. One end of the coil is connected to the grounding protective cover at the position where it is respectively connected to the first return layer and the second return layer. One end of the feeder is connected to the output end of the upper electrode radio frequency source device; The other ends of the first reflux layer and the second reflux layer are respectively connected to the housing of the upper electrode radio frequency source device.

[0008] This application embodiment also provides another semiconductor process apparatus, including: a cavity, a lower electrode device and a lower electrode radio frequency source device, wherein the lower electrode device includes an interface disk, a base and the above-mentioned radio frequency current transmission structure, wherein the interface disk serves as the grounding element and is disposed in the cavity, and the base serves as the radio frequency receiver, is disposed in the cavity and connected to the interface disk; One end of the feeder is connected to the output end of the lower electrode radio frequency source device; The other ends of the first reflux layer and the second reflux layer are respectively connected to the housing of the lower electrode radio frequency source device.

[0009] This application also provides a method for detecting radio frequency current, applied to the above-mentioned radio frequency current transmission structure, the detection method comprising: The magnetic field generated on the current acquisition device is detected; When the magnetic field formed on the current acquisition device is zero, it is determined that there is radio frequency current passing through the first return layer and no radio frequency current passing through the second return layer. When the magnetic field formed on the current acquisition device is an alternating magnetic field, it is determined that radio frequency current passes through the first return layer and the second return layer respectively.

[0010] This application also provides a method for testing a machine tool, applied to the aforementioned semiconductor process equipment, the method comprising: The reference sampling current of the upper or lower electrode device of the semiconductor process equipment for historical process matching machines is statistically analyzed, and a database of the reference sampling current is established. By statistically analyzing the normally distributed parameters in the database, a preset data range for the reference sampling current is determined. The sampling current of the upper electrode device or the lower electrode device of the new machine tool is detected; Determine whether the sampled current is within the preset data range; If so, then the connection between the components of the machine is considered to be normal; If not, then the connection between the components of the machine tool is determined to be abnormal.

[0011] In this embodiment, an RF current confinement transmission loop can be formed through the RF current transmission structure. A portion of the current flowing into the feed element returns through the first return layer to form an inner return path, while the other portion returns through the second return layer to form an outer return path. Since the magnetic material layer is located between the first and second return layers, the equivalent resistance of the current through the outer return path is larger, resulting in a higher impedance and thus weakening the current in the outer return path. Ultimately, more current is confined to the inner return path. Therefore, this effectively alleviates the problem of the RF current distribution being affected by the asymmetry of the external hardware structure, further improving the uniformity of the RF current distribution. Furthermore, compared to related technologies that compensate through structural adjustments, this embodiment does not require cumbersome structural adjustments, thereby reducing operational difficulty and avoiding the impact of structural adjustments on process performance. Attached Figure Description

[0012] Figure 1 This is a first schematic diagram of the semiconductor process equipment disclosed in the embodiments of this application; Figure 2 This is a second schematic diagram of the semiconductor process equipment disclosed in the embodiments of this application; Figure 3 This is a first schematic diagram of the first type of radio frequency current transmission structure disclosed in the embodiments of this application; Figure 4 This is a second schematic diagram of the first type of radio frequency current transmission structure disclosed in the embodiments of this application; Figure 5 This is a schematic diagram of the current acquisition element in the first type of radio frequency current transmission structure disclosed in the embodiments of this application; Figure 6 This is a schematic diagram of the first equivalent circuit model of the first form of radio frequency current transmission structure disclosed in the embodiments of this application; Figure 7 This is a schematic diagram of the second equivalent circuit model of the first type of radio frequency current transmission structure disclosed in the embodiments of this application; Figure 8 This is a schematic diagram of the first equivalent circuit model of the second form of radio frequency current transmission structure disclosed in the embodiments of this application; Figure 9 This is a schematic diagram of the second equivalent circuit model of the second form of radio frequency current transmission structure disclosed in the embodiments of this application; Figure 10 This is a first schematic diagram of the second form of radio frequency current transmission structure disclosed in the embodiments of this application; Figure 11 This is a second schematic diagram of the second form of radio frequency current transmission structure disclosed in the embodiments of this application; Figure 12 This is a flowchart of the machine consistency evaluation disclosed in an embodiment of this application.

[0013] Explanation of reference numerals in the attached figures: 10-RF current transport structure; 11-Feeder; 12-Dielectric layer; 13-First return layer; 131-Trench; 14-Magnetic material layer; 141-Recessed groove; 15-Second return layer; 16-Current acquisition device; 161-Rogowski coil; M-First transmission side; N-Second transmission side; 01-Cavity; 02-Upper electrode device; 021-Grounding protection cover; 022-Induction coil; 03-Lower electrode assembly; 031-Interface plate; 032-Base; 04-Upper electrode RF source device; 041-Upper electrode RF power supply; 042-Upper electrode matching unit; 05-Lower electrode RF source device; 051-Lower electrode RF power supply; 052-Lower electrode matching unit; 06-Signal processing device. Detailed Implementation

[0014] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0015] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0016] The embodiments of this application will be described in detail below with reference to the accompanying drawings and specific examples and application scenarios.

[0017] refer to Figures 1 to 11 This application discloses a radio frequency current transmission mechanism applied to semiconductor process equipment. The disclosed radio frequency current transmission structure 10 includes a feed element 11, a dielectric layer 12, a first return layer 13, a magnetic material layer 14, and a second return layer 15, and the feed element 11, dielectric layer 12, first return layer 13, magnetic material layer 14, and second return layer 15 are arranged sequentially from the inside to the outside.

[0018] One end of the feeder 11 is used to receive radio frequency (RF) current, and the other end of the feeder 11 is used to connect to the RF receiver of the semiconductor process equipment. In this way, the RF current can be transmitted to the RF receiver through the feeder 11 to provide power for the semiconductor process. One end of the first return layer 13 and the second return layer 15 are respectively used to connect to the grounding device of the semiconductor process equipment, and the RF receiver is connected to the grounding device. The other end of the first return layer 13 and the second return layer 15 are respectively used to lead out the RF current. Based on the above configuration, the feeder 11, the RF receiver, the grounding device, and the first return layer 13 together form an inner return path, while the feeder 11, the RF receiver, the grounding device, and the second return layer 15 together form an outer return path. Thus, a portion of the RF current flowing into the feeder 11 returns through the inner return path and is led out, while the other portion of the current is led out through the outer return path.

[0019] like Figure 3 The diagram illustrates the propagation path of the radio frequency (RF) current in the RF current transmission structure 10. The RF current flows in along the RF current feed surface (i.e., the outer surface of the feed element 11), and the direction indicated by the arrow is the current path direction. There are two return paths: an inner return path formed by the first return layer 13 and an outer return path formed by the second return layer 15. The direction of the RF current in both return paths is the same and opposite to the direction of the RF current in the input path. Since the RF current is time-varying, Figure 3It describes the marker at a certain moment; at different moments, the relative relationship of the current direction in each current path remains unchanged.

[0020] In this embodiment, the presence of the magnetic material layer 14 can have a certain influence on the current distribution in the inner and outer return paths, making the entire current path more concentrated and symmetrical, thereby improving the symmetry of the plasma in the process chamber of the semiconductor process equipment.

[0021] Specifically, by setting a magnetic material layer 14 between the first return layer 13 and the second return layer 15, the equivalent inductance generated during the return of RF current through the external return path is larger, i.e., greater than the equivalent inductance generated during the return of RF current through the internal return path. This results in a larger impedance in the external return path, thus significantly weakening the current in the external return path. Simultaneously, since the inner loop formed by the incoming current path (i.e., the current path within the feed unit 11) and the internal return path does not bypass the magnetic material layer 14, the magnetic material layer 14 does not significantly weaken the current in the internal return path. Therefore, the majority of the current is confined within the internal return path, making the current in the internal return path greater than the current in the external return path; that is, the current in the first return layer 13 is greater than the current in the second return layer 15.

[0022] It should be noted here that, because a magnetic material layer 14 is wrapped around the inner return path, the inner loop formed by the incoming current path and the inner return path does not wrap around the magnetic material layer 14, while the outer loop formed by the incoming current path and the outer return path does wrap around the magnetic material layer 14. That is, the radio frequency current in the outer loop wraps around the magnetic material. Let the magnetic field strength formed by the radio frequency current in this outer loop be H. Under the action of the magnetic material layer 14, the magnetic induction intensity is amplified to B, where B = μ. r μ0H, where μ r ρ represents the relative permeability of the magnetic material layer 14, and μ0 represents the free permeability. For example, using a nickel-zinc synthesized ferrite material, μ r The range is 20-10000, and the magnetic field strength is amplified. For example, the inductance of a single-turn long solenoid without a magnetic core material is L=μ0*S / L, while with a magnetic core material, L=μ r μ0*S / L, where S is the current loop area and L is the current loop length, has an equivalent effect similar to putting a magnetic ring on the wire, increasing the inductance of the wire, and thus increasing the impedance of the loop.

[0023] Based on the above configuration, by using the impedance constraints caused by the structure and magnetic material layer 14, the current received by the RF current transmission structure 10 and the RF current drawn out are more concentrated during the return flow. This can effectively alleviate the problem of signal transmission quality degradation caused by the RF current passing through other sensor cables (such as temperature measurement cables, heating cables, etc.) in the process chamber of the semiconductor process equipment, and the problem of large return current in other asymmetric cables or auxiliary connection devices of the RF current connected to the inductive coupling device connected to the RF current transmission structure 10. In this way, the RF current can be more concentrated and symmetrical during the return flow, which is beneficial to improving the symmetry of the plasma in the process chamber.

[0024] Taking the example of the radio frequency current transmission structure 10 connected between the upper electrode radio frequency source device 04 and the upper electrode device 02. Figure 6 and Figure 7 The diagram shows the equivalent circuit model of the upper electrode radio frequency current transmission structure 10. Among them, Figure 6 Z1 and Z2 represent the internal return path impedance and external return path impedance, respectively. The induction coil 022 of the upper electrode device 02 serves as a radio frequency receiver and can be an involute coil. The upper electrode device 02 has parasitic capacitance to the grounding device or plasma with which it has a relative area. Figure 7 It can be seen that, due to the presence of the magnetic material layer 14, Figure 6 The effect is that the impedance of the external return path is greater than that of the internal return path. The upper electrode RF source device 04 feeds RF current into the internal port of the upper electrode device 02, and the RF current returns from the external port of the upper electrode device 02. In addition, the upper electrode device 02 also transmits to the external return path of the RF current transmission structure 10 in a manner similar to capacitive coupling. The RF current in the internal return path surrounds the magnetic material layer 14, making the impedance Z1 smaller, while the RF current in the external return path surrounds the magnetic material layer 14, making the impedance Z2 larger. The current formed by the capacitive coupling part on the impedance Z2 of the external return path is very small.

[0025] The aforementioned capacitive coupling method refers to the existence of parasitic capacitances of relative area between the conductors opposite to it in the RF feed branch, such as the parasitic capacitance of the coil to the plasma and the parasitic capacitance of the coil to the cavity wall structure. The parasitic capacitance transmits capacitive coupling current, and the current returning through the parasitic capacitance is not in the internal return path of the RF current transmission structure 10.

[0026] Taking the example of the radio frequency current transmission structure 10 connected between the upper electrode radio frequency source device 04 and the upper electrode device 02. Figure 8 and Figure 9The diagram illustrates the equivalent circuit model of the lower electrode RF current transmission structure 10, which differs from the equivalent circuit model of the upper electrode RF current transmission structure 10. Specifically, the lower electrode RF source device 05 loads energy onto the base 032 of the lower electrode device 03 via the feeder 11 of the RF current transmission structure 10, and is capacitively coupled to the plasma; then, it returns through the return liner located around the base 032 to the first return layer 13 and the second return layer 15 of the RF current transmission structure 10, and flows back to the lower electrode RF source device 05 through impedances Z1 and Z2, respectively. Similar to the equivalent circuit model of the upper electrode RF current transmission structure 10, the RF current in the inner return path surrounds the magnetic material layer 14, resulting in a smaller impedance Z1, while the RF current in the outer return path surrounds the magnetic material layer 14, resulting in a larger impedance Z2. The current formed by the capacitive coupling part on the impedance Z2 of the outer return path is very small.

[0027] refer to Figure 3 and Figure 4 In some embodiments, the feed element 11, dielectric layer 12, first return layer 13, magnetic material layer 14, and second return layer 15 can be coaxial structures, which together form an overall columnar radio frequency current transmission structure 10. Exemplarily, the radio frequency current transmission structure 10 can be a cylindrical structure, a polygonal columnar structure, etc.

[0028] In some embodiments, the first return layer 13 may be sleeve-shaped and sleeved on the outside of the dielectric layer 12. Exemplarily, the first return layer 13 may be a circular sleeve structure, or it may be composed of multiple fan-shaped sleeve structures joined together. Alternatively, the first return layer 13 may be a metallic conductor layer, possessing good current transmission characteristics. Optionally, the inner diameter of the first return layer 13 may range from 78mm to 82mm, and the sidewall thickness may range from 3mm to 5mm.

[0029] The second return layer 15 can be sleeve-shaped, fitted over the outer side of the magnetic material layer 14. Exemplarily, the second return layer 15 can be a circular sleeve structure, or it can be composed of multiple fan-shaped sleeve structures joined together. Alternatively, the second return layer 15 can be a metallic conductor layer, possessing excellent current transmission characteristics. Optionally, the inner diameter of the second return layer 15 can range from 104 mm to 108 mm, and the sidewall thickness can range from 3 mm to 5 mm.

[0030] In some embodiments, the second return layer 15 can be an equipotential bonding layer made of metal, which can protect the internal magnetic material layer 14 from damage. Furthermore, the outer surface of this equipotential bonding layer is grounded so that the potential difference at different locations on the outer surface of the RF current transmission structure 10 is equal to or within the error range of the bonding layer, ensuring safe energy transmission and preventing capacitive RF energy coupling interference to external traces. It should be noted that because the RF return current is constrained by the impedance caused by the magnetic material layer 14, most of the RF current is confined within the first return layer 13. When the RF current-constrained transmission loop is long, there will be a large potential difference on the first return layer 13, while the RF current flowing through the equipotential bonding layer is very small (typically a few milliamps), so no large potential difference is generated, ensuring the safety of energy transmission. When transmitting high-frequency RF current, due to the skin effect of high-frequency signals, the RF current tends to propagate towards the outer surface of the feeder 11, while the RF return current tends to propagate towards the inner surface of the first return layer 13.

[0031] In addition, the feed element 11 can be a cylinder and the dielectric layer 12 can both be circular sleeve-shaped structures. For example, the diameter of the feed element 11 can be tens of millimeters, for example, the diameter range of the feed element 11 can be 34mm~37mm, and its outer surface is the feed surface of the radio frequency current.

[0032] In this embodiment, an impedance control medium is filled between the feed member 11 and the first return layer 13 to form a dielectric layer 12. Exemplarily, the impedance control medium can be air, but other media are also possible, and no specific limitation is made here.

[0033] In some embodiments, the magnetic material layer 14 can be an integral cylindrical structure, which can ensure that the magnetic material layer 14 has high strength and is not easily damaged.

[0034] In other embodiments, the magnetic material layer 14 may further include multiple magnetic units connected sequentially along the circumference of the radio frequency current transmission structure 10 to form a cylindrical structure. This type of magnetic material layer 14 is easy to process and manufacture, reducing the difficulty of processing and manufacturing.

[0035] In other embodiments, the magnetic material layer 14 may include multiple magnetic rings arranged sequentially along the axial direction of the radio frequency current transmission structure 10 to form a cylindrical structure. This type of magnetic material layer 14 is easy to process and manufacture, reducing the difficulty of processing and manufacturing.

[0036] Based on the above approach, the magnetic material layer 14 in the embodiments of this application can be an integral structure or a split structure customized according to specific dimensions and usage frequency to meet working condition requirements.

[0037] For example, the magnetic material layer 14 has a circular cylindrical structure with a sidewall thickness typically in the tens of millimeters, for example, ranging from 8 mm to 12 mm. Furthermore, the magnetic material layer 14 can be made of a nickel-zinc synthesized ferrite material.

[0038] In some embodiments, the type of magnetic material layer 14 can be adjusted so that the ratio of the radio frequency current in the second return layer 15 to the radio frequency current in the first return layer 13 can be less than or equal to 0.5% to meet actual needs.

[0039] To enable current detection, the radio frequency current transmission structure 10 may further include a current acquisition element 16, such as... Figure 3 As shown, the current acquisition device 16 is disposed in the region of the magnetic material layer 14 near the first return layer 13 and is arranged around the first return layer 13. The current acquisition device 16 is used to connect to the signal processing device 06 of the semiconductor process equipment to detect the radio frequency current in the second return layer 15. Optionally, the signal processing device 06 can be an oscilloscope.

[0040] It should be noted that if all the RF current flows back through the internal return path, the magnetic field formed by the current in the current input path and the current in the internal return path on the current acquisition device 16 cancels each other out, and the signal acquired by the signal processing device 06 is zero (close to the lowest noise signal). If a part of the RF current flows back through the external return path, an alternating magnetic field will be generated in the current acquisition device 16. The signal processing device 06 can detect the induced voltage and then convert it into current according to the ratio. The signal of this current can characterize the contact reliability of the electrical connection point of the transmission branch of the internal return path. If the internal return path connection is unstable, more of the RF current will flow back through the external return path.

[0041] For example, the current acquisition element 16 can be a ring-shaped structure, which can be embedded in the inner sidewall of the magnetic material layer 14. Alternatively, a slot can be made in the inner sidewall of the magnetic material layer 14 to accommodate the current acquisition element 16.

[0042] refer to Figure 5 In some embodiments, the current acquisition element 16 can be a Rogowski coil 161 made of thin metal wire. The input wire of the Rogowski coil 161 is wound around the magnetic material layer 14, and the output wire returns from the middle of each turn of the input wire.

[0043] Based on the aforementioned radio frequency current transport structure 10, this application also discloses a semiconductor process apparatus, referencing... Figures 1 to 11The disclosed semiconductor process equipment includes a cavity 01, an upper electrode device 02, and a lower electrode RF source device 05. The upper electrode device 02 includes a grounding shield 021, an induction coil 022, and the aforementioned RF current transmission structure 10. The grounding shield 021 serves as the grounding element and is located at the top of the cavity 01. The induction coil 022 serves as the RF receiver and is located at the top of the grounding shield 021. One end of the induction coil 022 is connected to the grounding shield 021 at the positions where it is connected to the first return layer 13 and the second return layer 15, respectively. One end of the feeder 11 is connected to the output terminal of the upper electrode RF source device, and the other ends of the first return layer 13 and the second return layer 15 are respectively connected to the housing of the upper electrode RF source device 04.

[0044] In some embodiments, the radio frequency current transmission structure 10 can be connected between the upper electrode radio frequency source device 04 and the upper electrode device 02. The upper electrode radio frequency source device 04 may include an upper electrode matching device 042 and an upper electrode radio frequency power supply 041. The upper electrode matching device 042 is located above the cavity 01, and the upper electrode radio frequency power supply 041 is connected to the upper electrode matching device 042. One end of the feeder 11 is connected to the upper electrode matching device 042 to feed radio frequency current into the feeder 11; the other end of the feeder 11 is connected to the induction coil 022 of the upper electrode device 02 to generate energy within the protective cover through the induction coil 022; and the energy generated by the induction coil 022 can excite plasma generation within the cavity 01. Based on the aforementioned radio frequency current transport structure 10, this application also discloses another semiconductor process apparatus, see reference. Figures 1 to 11 The disclosed semiconductor process equipment includes a cavity 01, a lower electrode device 03, and a lower electrode RF source device 05. The lower electrode device 03 includes an interface disk 031, a base 032, and the aforementioned RF current transmission structure 10. The interface disk 031 serves as the aforementioned grounding element and is located within the cavity 01. The base 032 serves as the aforementioned RF receiver, is located within the cavity 01, and is connected to the interface disk 031. Furthermore, one end of the feed-in element 11 is connected to the output end of the lower electrode RF source device 05, and the other ends of the first return layer 13 and the second return layer 15 are respectively connected to the housing of the lower electrode RF source device 05.

[0045] In some embodiments, the radio frequency current transmission structure 10 can be connected between the lower electrode radio frequency source device 05 and the lower electrode device 03. The lower electrode radio frequency source device 05 may include a lower electrode matching device 052 and a lower electrode radio frequency power supply 051. The lower electrode matching device 052 is located on the side of the cavity 01, and the lower electrode radio frequency power supply 051 is connected to the lower electrode matching device 052. One end of the feeder 11 is connected to the lower electrode matching device 052 to feed radio frequency current into the feeder 11; the other end of the feeder 11 is connected to the base 032 of the lower electrode device 03 to generate energy through the base 032 to adsorb plasma and provide the energy required for plasma acceleration.

[0046] Considering that the lower electrode RF source device 05 is located on the side of the cavity 01, it is impossible to achieve symmetry about the central axis of the cavity 01. Furthermore, the RF current transmission structure 10 has a right-angle turn, resulting in different RF current paths on different sides; that is, the current path lengths on different sides are geometrically asymmetrical. This embodiment compensates for the geometric asymmetry of the current path length by designing the magnetic material layer 14 to adjust the RF current return impedance.

[0047] In some embodiments, the radio frequency current transmission structure 10 may include a first transmission side M and a second transmission side N arranged circumferentially. Along the extending direction of the radio frequency current transmission structure 10, the length of the first transmission side M is smaller than the length of the second transmission side N. It should be noted that a portion of the radio frequency current transmission structure 10 forms a right-angle bend structure, wherein the side facing the bend direction is the first transmission side M, and the side facing away from the bend direction is the second transmission side N.

[0048] Considering that the radio frequency current transmission structure 10 includes a magnetic material layer 14, the magnetic material layer 14 can make the current return flow of radio frequency current between the base 032 and the lower electrode radio frequency source device 05 more concentrated, so as to reduce the interference of signal transmission path of signal acquisition and communication equipment connected to the process chamber, and at the same time, it can also optimize the geometric symmetry of the ion acceleration electric field between the surface of the base 032 and the plasma region.

[0049] Considering that the RF current transmission structure 10 between the lower electrode RF source device 05 and the base 032 adopts an asymmetric design, in the embodiments of this application, such as Figure 10 and Figure 11As shown, at least a portion of the first return layer 13 on the first transmission side M bends toward the magnetic material layer 14 to form a circumferentially extending trench 131, thereby extending the transmission path of the radio frequency current in the first return layer 13 on the first transmission side M. Based on this arrangement, by forming the circumferentially extending trench 131, the geometric asymmetry in the length of the radio frequency current return path caused by the asymmetric design of the short current path on the first transmission side M can be compensated, thereby improving the uniformity of the bias voltage on the substrate 032 surface.

[0050] In some embodiments, the first return layer 13 is formed with a plurality of trenches 131, which are arranged along the extension direction of the radio frequency current transmission structure 10. Based on this arrangement, the transmission path of the radio frequency current in the first return layer 13 of the first transmission side M can be further extended.

[0051] Correspondingly, the inner surface of the magnetic material layer 14 on the first transmission side M may also be provided with a plurality of recessed grooves 141 arranged along the extension direction of the radio frequency current transmission structure 10, and a plurality of trenches 131 are correspondingly provided in the plurality of recessed grooves 141. Based on this arrangement, the trenches 131 can be located in the corresponding receiving grooves, thereby effectively avoiding assembly interference between the first return layer 13 and the magnetic material layer 14.

[0052] It should be noted that, in order to facilitate the installation of the first return layer 13 and the magnetic material layer 14, in this embodiment of the application, the magnetic material layer 14 may include multiple magnetic units, which are connected sequentially along the circumference of the radio frequency current transmission structure 10 to form the radio frequency current transmission structure 10. This design can facilitate the installation of the first return layer 13 and the magnetic material layer 14.

[0053] like Figure 11 As shown, in some embodiments, the projection shape of the groove 131 in a plane perpendicular to the extension direction can be crescent-shaped. This shape can both extend the current return path and facilitate processing.

[0054] Correspondingly, the projection shape of the recessed groove 141 in the plane perpendicular to the extension direction can be crescent-shaped. This shape can both extend the current return path and facilitate processing.

[0055] Based on the aforementioned radio frequency current transmission structure 10, this application also discloses a radio frequency current detection method applied to the aforementioned radio frequency current transmission structure 10. The radio frequency current transmission structure 10 may further include a current acquisition element 16, which is disposed in the region of the magnetic material layer 14 near the first return current layer 13 and surrounding the first return current layer 13. The current acquisition element 16 is used to connect to the signal processing device 06 of the semiconductor process equipment. (Reference) Figures 1 to 11 The disclosed testing methods include: The magnetic field generated on the current acquisition device 16 is detected; When the magnetic field formed on the current acquisition device 16 is zero, it is determined that there is radio frequency current passing through the first return layer 13 and no radio frequency current passing through the second return layer 15. When the magnetic field formed on the current acquisition device 16 is an alternating magnetic field, it is determined that radio frequency currents pass through the first return layer 13 and the second return layer 15 respectively.

[0056] In some embodiments, when the magnetic field formed on the current acquisition device 16 is an alternating magnetic field, the induced voltage is obtained by the signal processing device 06 and converted into radio frequency current in the second return layer 15 according to a preset ratio based on the induced voltage.

[0057] It should be noted that if the RF current flows back through the inner return path (i.e., the first return layer 13), the magnetic field formed on the current acquisition device 16 by the current in the current input path and the current in the inner return path cancels each other out, and the signal acquired by the signal processing device 06 is zero (close to the lowest noise signal). If a part of the RF current flows back through the outer return path (i.e., the second return layer 15), an alternating magnetic field will be generated in the current acquisition device 16. The signal processing device 06 can detect the induced voltage and then convert it into current proportionally. The signal of this current can characterize the contact reliability of the electrical connection point of the transmission branch of the inner return path. If the connection of the inner return path is unstable, the RF current will flow back through the outer return path more.

[0058] Based on the aforementioned semiconductor process equipment, this application also discloses a testing method for the machine, applied to the aforementioned semiconductor process equipment. (Reference) Figures 1 to 12 The disclosed testing methods include: The reference sampling current of the upper electrode device 02 or lower electrode device 03 of the semiconductor process equipment matched with the historical process is statistically analyzed, and a database of reference sampling currents is established. By statistically analyzing the normally distributed parameters in the database, the preset data range of the reference sampling current is determined. Detect the sampling current of the upper electrode device 02 or the lower electrode device 03 of the new machine; Determine whether the sampled current is within the preset data range; If so, then the connection of the machine's radio frequency energy feed system is normal; If not, the connection of the machine's radio frequency energy feed system is determined to be abnormal.

[0059] It should be noted that, due to the numerous manually installed components in semiconductor process equipment, the reliability of connections in critical radio frequency (RF) energy feed circuits directly impacts process performance. Unreliable connections, with their unpredictable intermittent operation, will affect the progress of process development. In this embodiment, after the equipment is installed, the signal collected by the current acquisition unit 16 and processed by the signal processing device 06 is used to determine whether the RF energy feed system of the equipment is properly connected.

[0060] Specifically, firstly, the sampling current data of the upper electrode device 02 or lower electrode device 03 of the historical process matching machine is collected as a reference sampling current. Then, a database of sampling current data of batch process matching machines is established, that is, a database of reference sampling currents is established. The normal distribution parameters in the database are statistically analyzed to determine the normal value range [a, b], that is, to determine the preset data range. After the new machine is installed, the sampling current of the new machine can be collected, and it is determined whether the sampling current is within the normal value range [a, b], where [a, b] can be [0, 10] mA. When the current is greater than b, it is determined that part of the RF current flows back through the external return path (i.e., the outer loop), and the current flowing back through the internal return path (i.e., the main loop) is divergent, thus affecting the uniformity of the process. At this time, it is necessary to check the installation of the machine until the data meets the normal value range. Therefore, this detection method can help improve the quality of the machine leaving the factory.

[0061] In summary, by employing the RF current transmission structure 10, the external return path impedance is made greater than the internal return path impedance, which further confines the RF current within the RF current transmission structure 10. This significantly reduces the impact of the asymmetry of the external structure on the RF current distribution, thus improving the geometric uniformity of the RF current distribution. Furthermore, by designing the trench 131, the geometric inconsistency of impedance caused by the trace path length can be compensated, thereby greatly reducing the RF current flowing through the traces outside the process chamber, and further reducing the RF interference of the RF current to the external components of the process chamber.

[0062] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A radio frequency current transmission structure, applied in semiconductor process equipment, characterized in that, The radio frequency current transmission structure (10) includes: a feeder (11), a dielectric layer (12), a first return layer (13), a magnetic material layer (14), and a second return layer (15) arranged sequentially from the inside to the outside; One end of the feeder (11) is used to receive radio frequency current, and the other end of the feeder (11) is used to connect to the radio frequency receiver of the semiconductor process equipment. One end of the first return layer (13) and the second return layer (15) are respectively used to connect to the grounding device of the semiconductor process equipment. The radio frequency receiver is connected to the grounding device. The other end of the first return layer (13) and the second return layer (15) are respectively used to lead out radio frequency current, and the current in the first return layer (13) is greater than the current in the second return layer (15).

2. The radio frequency current transmission structure according to claim 1, characterized in that, The first reflux layer (13) is sleeve-shaped; And / or, the second reflux layer (15) is sleeve-shaped.

3. The radio frequency current transmission structure according to claim 1, characterized in that, The magnetic material layer (14) is an integral cylindrical structure; Alternatively, the magnetic material layer (14) may include multiple magnetic units, which are sequentially connected along the circumference of the radio frequency current transmission structure (10) to form a cylindrical structure. Alternatively, the magnetic material layer (14) may include multiple magnetic rings, which are stacked sequentially along the axial direction of the radio frequency current transmission structure (10) to form a cylindrical structure.

4. The radio frequency current transmission structure according to claim 1, characterized in that, The feed element (11), the dielectric layer (12), the first return layer (13), the magnetic material layer (14), and the second return layer (15) are coaxially arranged.

5. The radio frequency current transmission structure according to claim 1, characterized in that, The second return layer (15) is an equipotential protection layer made of metal. The outer surface of the equipotential protection layer is grounded so that the potential difference at different positions on the outer surface of the radio frequency current transmission structure (10) is equal to or within the error range of the protective ground potential.

6. The radio frequency current transmission structure according to claim 1, characterized in that, The proportion of the radio frequency current in the second return layer (15) to the radio frequency current in the first return layer (13) is less than or equal to 0.5%.

7. The radio frequency current transmission structure according to claim 1, characterized in that, The radio frequency current transmission structure (10) further includes a current acquisition device (16), which is disposed in the region of the magnetic material layer (14) near the first return layer (13) and surrounding the first return layer (13). The current acquisition device (16) is used to connect to the signal processing device (06) of the semiconductor process equipment to detect the radio frequency current in the second return layer (15).

8. A semiconductor process apparatus, characterized in that, include: The cavity (01), the upper electrode device (02) and the upper electrode radio frequency source device (04) are provided. The upper electrode device (02) includes a grounding protection cover (021), an induction coil (022) and a radio frequency current transmission structure (10) as described in any one of claims 1 to 7. The grounding protection cover (021) serves as the grounding element and is located on the top of the cavity (01). The induction coil (022) serves as the radio frequency receiver and is located inside the grounding protection cover (021). One end of the induction coil (022) is connected to the grounding protection cover (021) at the positions where it is connected to the first return layer (13) and the second return layer (15) respectively. One end of the feeder (11) is connected to the output end of the upper electrode radio frequency source device (04); The other ends of the first reflux layer (13) and the second reflux layer (15) are respectively connected to the housing of the upper electrode radio frequency source device (04).

9. A semiconductor process apparatus, characterized in that, include: The device comprises a cavity (01), a lower electrode device (03), and a lower electrode radio frequency source device (05). The lower electrode device (03) includes an interface disk (031), a base (032), and a radio frequency current transmission structure (10) as described in any one of claims 1 to 7. The interface disk (031) serves as the grounding element and is disposed within the cavity (01). The base (032) serves as the radio frequency receiver, is disposed within the cavity (01), and is connected to the interface disk (031). One end of the feeder (11) is connected to the output end of the lower electrode radio frequency source device (05); The other ends of the first reflux layer (13) and the second reflux layer (15) are respectively connected to the housing of the lower electrode radio frequency source device (05).

10. The semiconductor process equipment according to claim 9, characterized in that, The radio frequency current transmission structure (10) includes a first transmission side (M) and a second transmission side (N) arranged circumferentially. Along the extension direction of the radio frequency current transmission structure (10), the length of the first transmission side (M) is smaller than the length of the second transmission side (N). At least a portion of the first return layer (13) of the first transmission side (M) bends toward the magnetic material layer (14) to form a trench (131) extending along the circumferential direction to extend the transmission path of the radio frequency current in the first return layer (13) of the first transmission side (M).

11. The semiconductor process equipment according to claim 10, characterized in that, The first reflux layer (13) has a plurality of said trenches (131) arranged along the extension direction; The inner surface of the magnetic material layer (14) of the first transmission side (M) is provided with a plurality of recessed grooves (141) arranged along the extension direction, and the plurality of grooves (131) are correspondingly provided in the plurality of recessed grooves (141).

12. The semiconductor process equipment according to claim 11, characterized in that, The projection shape of the groove (131) in a plane perpendicular to the extension direction is crescent-shaped; And / or, the projection shape of the recess (141) in a plane perpendicular to the extension direction is crescent-shaped.

13. A method for detecting radio frequency current, applied to the radio frequency current transmission structure (10) according to any one of claims 1 to 6, characterized in that, The radio frequency current transmission structure (10) further includes a current acquisition device (16), which is disposed in the region of the magnetic material layer (14) near the first return layer (13) and surrounding the first return layer (13). The current acquisition device (16) is used to connect to the signal processing device (06) of the semiconductor process equipment. The detection method includes: The magnetic field formed on the current acquisition device (16) is detected; When the magnetic field formed on the current acquisition device (16) is zero, it is determined that there is radio frequency current passing through the first return layer (13) and no radio frequency current passing through the second return layer (15). When the magnetic field formed on the current acquisition device (16) is an alternating magnetic field, it is determined that radio frequency current passes through the first return layer (13) and the second return layer (15).

14. The detection method according to claim 13, characterized in that, When the magnetic field formed on the current acquisition device (16) is an alternating magnetic field, the induced voltage is obtained by the signal processing device (06) and converted into radio frequency current in the second return layer (15) according to the induced voltage in a preset ratio.

15. A method for testing a machine tool, applied to the semiconductor process equipment as described in claim 8 or 9, characterized in that, The detection method includes: The reference sampling current of the upper electrode device (02) or lower electrode device (03) of the semiconductor process equipment of the historical process matching machine is statistically analyzed, and a database of the reference sampling current is established. By statistically analyzing the normally distributed parameters in the database, a preset data range for the reference sampling current is determined. The sampling current of the upper electrode device (02) or the lower electrode device (03) of the new machine is detected; Determine whether the sampled current is within the preset data range; If so, the radio frequency energy feed system of the machine is determined to be connected normally; If not, the connection of the radio frequency energy feed system of the machine is determined to be abnormal.

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