Radio frequency feed structure for a plasma chamber and substrate processing apparatus

Abstract

The application belongs to the technical field of deposition, and provides a radio frequency feeding structure of a plasma chamber and a substrate processing device, wherein the radio frequency feeding structure of the plasma chamber comprises a feeding rod and a capacitance structure, the capacitance structure comprises at least one capacitance in parallel with the feeding rod, and the capacitance is used for adjusting the voltage of the feeding rod when plasma is ignited. The application can improve the vacuum side voltage when plasma is ignited, reduce power loss, and improve response speed.

Description

Technical Field

[0001] This invention belongs to the field of deposition technology and relates to the radio frequency feeding structure of a plasma chamber and a substrate processing device. Background Technology

[0002] Plasma chemical vapor deposition (PECVD) is a chemical vapor deposition technique that uses plasma to activate reactive gas precursors at relatively low temperatures (typically 200–400°C), causing them to chemically react on the substrate surface and deposit solid thin films.

[0003] The plasma chemical substrate processing device includes a radio frequency power supply, an impedance matching network, a radio frequency feed structure for the plasma chamber, and the plasma chamber itself. The radio frequency power supply is used to generate and output radio frequency electrical signals of a preset frequency and power level to provide the alternating electric field energy required to excite and maintain the plasma in the plasma chemical vapor deposition process; Impedance matching networks are used to dynamically or statically adjust the conjugate matching relationship between the RF power supply output impedance and the plasma chamber load impedance to maximize the transmission efficiency of RF power to the plasma load and suppress reflection loss. The radio frequency (RF) feed structure of the plasma chamber is used to transmit the impedance-matched RF power from the atmospheric side across the vacuum-sealed boundary and couple it to the RF electrodes inside the plasma chamber to establish an alternating electric field between the electrodes for exciting the process gas. Plasma chambers are used to provide a closed, controlled-pressure vacuum reaction environment to contain the plasma discharge region and support the wafer to complete the thin film deposition process.

[0004] The existing RF feeding structure of a plasma chamber includes a feed rod, an upper electrode (spray head), an insulating ring / dielectric layer, and a vacuum coupling interface. The feed rod introduces the RF current from the impedance matching network from the atmospheric side to the vacuum side. The upper electrode (spray head) is located above the wafer inside the plasma chamber. After receiving the RF power transmitted by the feed rod, it serves as the RF discharge electrode, forming an RF electric field between itself and the grounded lower electrode. At the same time, it distributes process gas to the discharge gap region through the spray holes evenly distributed on its surface. The insulating ring / dielectric layer is sandwiched between the outer periphery of the upper electrode and the grounded cavity wall, electrically isolating the upper electrode from the grounded cavity wall and vacuum sealing it to prevent RF power leakage to the cavity wall. The vacuum coupling interface is located at the position where the feed rod passes through the cavity wall. While isolating the atmospheric and vacuum environments, it couples the RF power from the atmospheric side to the vacuum side.

[0005] The existing radio frequency feeding structure of the plasma chamber provides a fixed electrode-side (vacuum-side) voltage during plasma ignition, which presents the following technical problems: Low process power: In the existing structure, the feed rod introduces the radio frequency current from the atmospheric side to the vacuum side and transmits it to the upper electrode. However, since the insulating ring / dielectric layer is sandwiched between the outer periphery of the upper electrode and the grounding cavity wall, a parasitic capacitance and grounding path are formed around the upper electrode. This causes some radio frequency current to leak to the grounding cavity wall through the insulating ring before reaching the discharge gap. At the same time, there is an inherent impedance discontinuity and coupling loss at the vacuum coupling interface where the feed rod passes through the cavity wall. The feed rod itself also has transmission loss. The superposition of the above multiple power dispersion and energy attenuation mechanisms leads to a significant reduction in the effective process power finally coupled to the discharge gap.

[0006] Slow recovery: Existing technologies use fixed electrode-side voltages, forming a rigid connection between the feed rod and the impedance matching network. The vacuum coupling interface only provides fixed power coupling transmission characteristics and cannot respond quickly to plasma ignition transients. In addition, the insulating ring / dielectric layer is polarized and accumulates bound charges under the action of the radio frequency field. Its dielectric relaxation process causes a lag in charge release, making it difficult for the electric field between the upper and lower electrodes to quickly rebuild a steady-state distribution after drastic changes in ignition. This results in a slow process of the system recovering from the ignition transient to a stable discharge state.

[0007] Insufficient ignition edge and the resulting unstable or delayed ignition: The feed rod usually introduces radio frequency power from the central region or a specific location of the upper electrode. When the radio frequency current propagates within the surface of the upper electrode, it is mainly concentrated in the central region due to the path impedance and distributed inductance. At the same time, the insulating ring / dielectric layer is tightly sandwiched between the outer periphery of the upper electrode and the ground cavity wall. Its high dielectric constant material and the boundary constraint of the ground cavity wall weaken the electric field strength in the edge region of the upper electrode, making the radio frequency voltage in the edge region significantly lower than that in the central region. As a result, the electric field strength at the edge of the discharge gap is insufficient to break down the gas and form the initial plasma, resulting in insufficient edge ignition, unstable ignition, or delayed ignition.

[0008] Limited Dynamic Control of Electrode-Side Voltage Performance: In the existing structure, the vacuum coupling interface serves only as a fixed coupling port for the feed rod to pass through the chamber wall, lacking voltage regulation, phase control, or real-time feedback functions. The feed rod, as a rigid transmission channel connecting the impedance matching network and the upper electrode, has a fixed physical connection relationship, making it impossible to dynamically change the transmission characteristics without disrupting the vacuum seal. The dielectric parameters and geometric position of the insulating ring / dielectric layer are also fixed, making it impossible to dynamically change the electric field and potential distribution around the upper electrode by adjusting the dielectric properties. Therefore, the entire feed structure lacks physical means and feedback pathways for dynamically regulating the vacuum-side electrode voltage during ignition, severely limiting its dynamic control performance.

[0009] Low maximum voltage amplitude on the vacuum side: The vacuum coupling interface has inherent impedance transformation effects and coupling transmission losses at the location where the feed rod crosses the chamber wall, causing RF power to be reflected and attenuated when crossing the atmosphere-vacuum boundary. During the transmission of the feed rod from the atmosphere side to the vacuum side, the voltage amplitude is further reduced due to standing waves and conductor losses. At the same time, a large area of ​​parasitic capacitance is formed between the insulating ring / dielectric layer and the outer periphery of the upper electrode and the grounding cavity wall, which creates a significant shunt path for the RF current received by the upper electrode. In addition, the upper electrode of the spray head structure has a large distributed capacitance, and the RF current is greatly shunted and attenuated before reaching the discharge gap. The superposition of the above multiple attenuation mechanisms ultimately limits the maximum voltage amplitude that the upper electrode on the vacuum side can establish.

[0010] Therefore, there is an urgent need for a radio frequency feeding structure for plasma chambers that reduces power loss and improves response speed. Summary of the Invention

[0011] In view of the above problems, one embodiment of the present invention aims to provide a radio frequency power supply structure for a plasma chamber, which has high process power, fast state recovery, stable and fast plasma ignition, and can also improve the ability to dynamically control the electrode side (vacuum side) voltage during the ignition process.

[0012] Another object of one embodiment of the present invention is to provide a substrate processing apparatus.

[0013] A third objective of one embodiment of the present invention is to provide a substrate processing apparatus and method.

[0014] According to a first aspect of the present invention, a radio frequency feeding structure for a plasma chamber is provided, comprising a feeding rod and a capacitor structure, the capacitor structure comprising at least one capacitor connected in parallel with the feeding rod, the capacitor being used to adjust the voltage of the feeding rod during plasma ignition.

[0015] In one possible implementation, the capacitor structure includes a fixed capacitor and / or a variable capacitor.

[0016] In one possible implementation, the capacitor structure includes a fixed capacitor and a variable capacitor connected in parallel. The fixed capacitor provides a base capacitance during plasma ignition, and the variable capacitor adjusts the vacuum-side voltage after plasma ignition.

[0017] In one possible implementation, the capacitor structure further includes a switch control, which is electrically connected to the fixed capacitor and the variable capacitor respectively, to control the fixed capacitor and the variable capacitor to be connected in parallel to the feed rod simultaneously or at different times.

[0018] In one possible implementation, the capacitor structure is connected in parallel at one or more locations below the feed rod: The feeder pole consists of an atmospheric section, a transition section, and a vacuum section.

[0019] In one possible implementation, the capacitor structure is connected in parallel to the atmospheric section of the feeder rod.

[0020] In one possible implementation, the capacitor structure includes at least one fixed or variable capacitor connected in parallel with the feed rod.

[0021] In one possible implementation, the capacitor structure further includes a switch control that controls the timing of multiple fixed capacitors connected in parallel with the feed rod; or, the switch control controls the timing of multiple variable capacitors connected in parallel with the feed rod.

[0022] In one possible implementation, the capacitance value of the capacitor structure is determined based on radio frequency parameters, plasma physical characteristics, process requirements, and equipment structure. The radio frequency parameters include one or more of the following: operating frequency, rated output power and reflected power threshold of the radio frequency power supply, and dynamic variation range of plasma load impedance. The plasma physical characteristics include one or more of the following: breakdown voltage threshold of process gas, plasma steady-state equivalent resistance, plasma sheath capacitance, impedance jump amplitude, and response time constant. The process requirements include one or more of the following: target vacuum side voltage, chamber process pressure, thin film deposition rate, and power level. The equipment structure includes one or more of the following: geometric length and cross-sectional area of ​​the feed rod, coaxial distributed capacitance between the feed rod and the grounding cavity wall, dielectric constant and thickness of the insulating ring / dielectric layer, coverage area and installation position of the inner liner ring, and radial dimensions of the edge ring / focusing ring.

[0023] According to a second aspect of the present invention, a substrate processing apparatus is provided, comprising: The plasma chamber has a processing space inside for processing the substrate; A substrate support is disposed inside the plasma chamber for placing the substrate; A gas spraying section is configured to face the substrate support section and is used to supply process gas to the substrate. A radio frequency power supply provides radio frequency power to at least one of the gas spray section and the substrate support section to form plasma between the substrate support section and the gas spray section; And an impedance matching network for matching plasma impedance during plasma formation. This also includes: The radio frequency feeding structure of the plasma chamber is used to regulate the ignition of the plasma formed in the processing space of the plasma chamber.

[0024] Beneficial effects: The radio frequency (RF) feed structure of the plasma chamber described in this invention utilizes a capacitor structure connected in parallel at both ends of the feed rod. This capacitor, along with the parasitic inductance of the feed rod itself, forms an LC parallel impedance transformation network, altering the amplitude and phase of the equivalent impedance on the power supply side. This alters the total parasitic capacitive load at the node, formed by the parasitic capacitance at the edge of the insulating ring / dielectric layer, the stray capacitance at the vacuum coupling interface, and the coupling capacitance of the support structure. This significantly reduces the total series impedance from the RF power supply to the vacuum-side electrode, increasing the node voltage and the main path current. Consequently, during the plasma ignition stage, the vacuum-side voltage is significantly increased to a level sufficient to break down the gas in the edge region, solving the problems of insufficient ignition edge, unstable ignition, or delay in the prior art. Simultaneously, the high voltage rapidly establishes plasma, shortening the state recovery time. During the stable plasma deposition stage, the capacitance value of the capacitor structure is adjusted to track the dynamic drift of the plasma load impedance in real time and perform fine impedance matching, minimizing the RF reflection power. This achieves dynamic control of the vacuum-side electrode voltage, solving the problems of low process power, limited dynamic control of the electrode-side voltage performance, and limited maximum amplitude of the vacuum-side voltage.

[0025] The substrate processing apparatus of the present invention solves the problems of the prior art through the synergistic effect of its components: the radio frequency power supply generates radio frequency power, the impedance matching network performs preliminary impedance matching on the radio frequency power, the radio frequency feeding structure transmits the matched radio frequency power from the atmospheric side and couples it to the gas spray section, the gas spray section, as the upper electrode, and the substrate support section, as the lower electrode, are positioned opposite each other in the processing space of the plasma chamber, the gas spray section supplies process gas to the processing space, and the radio frequency power excites plasma in the processing space to process the substrate placed on the substrate support section; wherein, the radio frequency feeding structure includes a feeding rod and a capacitor structure connected in parallel with the feeding rod, the capacitor structure and the parasitic inductance of the feeding rod itself constitute an LC parallel impedance transformation network, by changing the amplitude and phase of the equivalent impedance on the power supply side, so that it is connected to the node of the radio frequency feeding structure by the parasitic capacitance of the insulating structure, The total parasitic capacitive load formed by the stray capacitance at the vacuum coupling interface and the coupling capacitance of the support structure is conjugately canceled, thereby significantly reducing the total series impedance from the RF power supply to the gas spray section and improving the node voltage and main path current transmission efficiency. Thus, during the plasma ignition stage, the RF feed structure significantly increases the vacuum-side voltage to a level sufficient to break down the gas in the edge region of the processing space, ensuring reliable edge ignition and rapid plasma establishment, solving the problems of low maximum amplitude of vacuum-side voltage, insufficient ignition edge, unstable or delayed ignition, and slow state recovery in the prior art. During the plasma stabilization stage, by adjusting the capacitance value of the capacitor structure to track the dynamic drift of the plasma load impedance in real time, fine impedance matching is achieved and the RF reflection power is minimized, thereby dynamically controlling the vacuum-side electrode voltage and maintaining maximum power transmission efficiency, solving the problems of low process power and limited dynamic control of electrode-side voltage performance. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of an embodiment of the radio frequency feeding structure of the plasma chamber described in this invention; Figure 2 This is a schematic diagram of one embodiment of the substrate processing apparatus described in this invention; Figure 3 This is a schematic diagram of the circuit principle of a simulation circuit of the radio frequency feeding structure of the plasma chamber described in this invention. Figure 4 This is a schematic diagram of the circuit principle of a preferred embodiment of the simulation circuit of the radio frequency feeding structure of the plasma chamber described in this invention; Figure 5 This is a coordinate graph of a specific embodiment of the vacuum side voltage during plasma ignition of the substrate processing device described in this invention. The horizontal axis represents the capacitance value of the capacitor structure, and the vertical axis represents the vacuum side voltage value. Wherein: 1. Feeding rod; 2. Spray head; 3. Insulating ring; 4. Inner liner ring; 10. RF feeding structure; 20. RF power supply with impedance matching network; 30. Plasma chamber; 40. Gas spray section; 50. Substrate support section; 100. Substrate processing device; V. RF power supply; C. Capacitor structure; C1. First capacitor; C2. Second capacitor; C3. Third capacitor; C4. Fourth capacitor; C5. Fifth capacitor; L1. First inductor; L2. Second inductor; L3. First inductor; R1. First resistor; R2. Second resistor; R3. Third resistor; Zp. Plasma load. Detailed Implementation

[0027] Numerous specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0028] The terminology used in one or more embodiments of the present invention is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. The singular forms “a” and “the” as used in one or more embodiments of the invention and in the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0029] Hereinafter, one or more embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art can clearly and completely understand the present invention. When the description of well-known structures or features would unnecessarily obscure the main points of the present invention, the description of such well-known structures or features will be omitted.

[0030] In existing plasma chamber RF feed structures, during plasma ignition, multiple factors such as the parasitic capacitance shunting of the insulating ring, the discontinuity of the vacuum coupling interface impedance, and transmission loss result in reduced effective process power and limited amplitude of the vacuum-side electrode voltage. At the same time, due to the rigid fixed feed connection and the charge relaxation hysteresis of the dielectric layer, the system lacks the ability to dynamically control the electrode-side voltage, making it difficult to adapt to transient changes in ignition. This leads to slow electric field reconstruction, insufficient edge ignition, and consequently, problems such as unstable ignition, delay, and a slow recovery from transient to steady-state discharge.

[0031] To address the aforementioned technical problems in the prior art, the present invention provides a radio frequency feeding structure for a plasma chamber, such as... Figure 1 As shown, the radio frequency feeding structure 10 of the plasma chamber includes a feeding rod 1 and a capacitor structure C connected in parallel with the feeding rod 1.

[0032] This invention forms a parallel resonant circuit by connecting the capacitor structure C in parallel with the distributed inductance of the feed rod 1 itself, generating a resonant boost effect near the RF operating frequency, which significantly increases the voltage amplitude transmitted from the feed rod 1 to the vacuum coupling interface. At the same time, the capacitor structure C connected in parallel with the feed rod 1 can compensate for the parasitic capacitance formed between the insulating ring 3 / dielectric layer and the ground cavity wall, reducing the shunt leakage of RF current to the cavity wall, allowing more power to be effectively transmitted to the upper electrode through the vacuum coupling interface, and finally distributed to the discharge gap through the spray head 2, thereby improving the effective process power.

[0033] The capacitor structure C connected in parallel with feed rod 1 stores electric field energy during the radio frequency cycle. When plasma ignition causes a sudden change in the discharge gap impedance, the capacitor can release the stored energy instantaneously, providing rapid voltage support for the upper electrode and shortening the electric field reconstruction time. At the same time, the capacitor structure C connected in parallel with feed rod 1 changes the impedance characteristics between feed rod 1 and the vacuum coupling interface, enabling the atmospheric impedance matching network to sense and respond to changes in vacuum load more quickly, accelerating the process of the system recovering from the ignition transient to the steady-state discharge.

[0034] The capacitance value of the capacitor structure C connected in parallel with the feed rod 1 can be designed or adjusted according to different process conditions. The resonant network formed by the capacitor structure C, the feed rod 1, and the upper electrode can adaptively adjust the transmission characteristics of RF power from the atmospheric side to the vacuum side. When the process gas or power conditions change, the capacitor structure C changes the electric field distribution and equivalent impedance at the boundary of the insulating ring 3 / dielectric layer, making the coupling relationship between the atmospheric side matching network and the vacuum side discharge load more flexible, thereby achieving a better impedance matching state in different process windows.

[0035] During the ignition phase, the capacitor structure C forms a high-Q resonance with the feed rod 1, generating significant voltage amplification at the vacuum coupling interface. This provides a higher initial breakdown voltage for the upper electrode, reduces the gas breakdown threshold, and makes the plasma easier to ignite. Simultaneously, as an energy storage element, the capacitor structure can buffer the drastic changes in load impedance during ignition, reduce reflected power, and make the load changes faced by the atmospheric impedance matching network smoother, thereby shortening the matching search time and improving ignition stability.

[0036] The capacitor structure C alters the impedance characteristics of the connection node between the feed rod 1 and the upper electrode, making the RF current distribution in the plane more uniform. This capacitor structure, together with the distributed capacitance of the upper electrode and the parasitic capacitance of the insulating ring 3 / dielectric layer, adjusts the electric field boundary conditions between the outer periphery of the upper electrode and the ground cavity wall, weakens the weakening effect of the insulating ring on the edge electric field, and increases the RF voltage in the edge region of the upper electrode. The electric field strength at the edge of the discharge gap is sufficient to break down the gas, eliminating insufficient edge ignition and ignition delay.

[0037] The capacitor structure C connected in parallel with feed rod 1 serves as a controllable energy storage / release element along the path of feed rod 1. Its charging and discharging process can dynamically adjust the voltage amplitude and phase at both ends of feed rod 1 and at the vacuum coupling interface. By controlling the capacitance value of the capacitor structure C connected in parallel with feed rod 1 or by cooperating with an external tuning circuit, the voltage of the upper electrode on the vacuum side can be dynamically adjusted without damaging the vacuum seal, breaking through the physical limitation that could not be controlled under the original fixed connection relationship.

[0038] The capacitor structure C connected in parallel with feed rod 1 and the distributed inductance of feed rod 1 form a resonant boost at the operating frequency. This resonant effect amplifies the RF voltage several times at the vacuum coupling interface. At the same time, the capacitor structure C connected in parallel with feed rod 1 reduces the equivalent impedance at the interface between feed rod 1 and vacuum, reducing power reflection and transmission loss, allowing more RF energy to be transmitted to the upper electrode across the atmosphere-vacuum boundary. In addition, this capacitor structure compensates for the parasitic shunting effect of the insulating ring / dielectric layer and the spray head structure, enabling the upper electrode to increase the RF voltage and meet the high electric field strength requirement of plasma ignition.

[0039] The capacitance value of capacitor structure C is determined based on radio frequency parameters, plasma physical characteristics, process requirements, and equipment structure. The radio frequency parameters include one or more of the following: operating frequency, rated output power and reflected power threshold of radio frequency power supply V, and dynamic variation range of plasma load impedance. The plasma physical characteristics include one or more of the following: breakdown voltage threshold of process gas, plasma steady-state equivalent resistance, plasma sheath capacitance, impedance jump amplitude, and response time constant. The process requirements include one or more of the following: target vacuum side voltage, chamber process pressure, thin film deposition rate, and power level. The equipment structure includes one or more of the following: geometric length and cross-sectional area of ​​feed rod 1, coaxial distributed capacitance between feed rod 1 and grounding cavity wall, dielectric constant and thickness of insulating ring / dielectric layer, coverage area and installation position of inner liner ring, and radial dimensions of edge ring / focusing ring.

[0040] In one feasible embodiment, the capacitance value of the capacitor structure is 5-500pF, and the vacuum side voltage can be controlled between 188-352V during plasma ignition under a 100V RF power supply.

[0041] In one feasible embodiment, the capacitor structure C includes at least one fixed capacitor.

[0042] Preferably, the capacitor structure C includes multiple fixed capacitors connected in parallel and a switching control. The multiple fixed capacitors are connected in parallel. The switching control controls the multiple fixed capacitors to conduct simultaneously or in a time-division manner, so that the capacitance value of the capacitor structure C is adapted to the plasma ignition stage and the plasma stable deposition stage, respectively. The vacuum side voltage required in the plasma ignition stage is higher than that in the plasma stable deposition stage (after plasma ignition). Therefore, preferably, the capacitance value of the capacitor structure C in the plasma ignition stage is greater than that in the plasma stable deposition stage.

[0043] In one feasible embodiment, the capacitor structure C includes at least one variable capacitor, which allows the capacitance value of the capacitor structure C to be adapted to both the plasma ignition stage and the plasma stable deposition stage. After ignition, no further high-power increase is required. The capacitance can be reduced or adjusted to maintain a stable RF operating state and minimize unnecessary capacitive current load.

[0044] In one feasible embodiment, the capacitor structure C includes a plurality of variable capacitors connected in parallel.

[0045] In one feasible embodiment, the capacitor structure C includes multiple variable capacitors and a switch control, wherein the switch control controls the multiple variable capacitors to conduct simultaneously or in a time-sharing manner.

[0046] In one feasible embodiment, the capacitor structure C includes at least one fixed capacitor, at least one variable capacitor, and a switching control: The fixed capacitor is connected in parallel with the feeder rod; The variable capacitor is connected in parallel with the feed rod; The switch control controls the fixed capacitor and the variable capacitor to conduct simultaneously or in a time-sharing manner.

[0047] Preferably, during the plasma ignition stage, the fixed capacitor is connected in parallel to the feed rod 1; During the plasma stabilization deposition stage, the variable capacitor is connected in parallel to the feed rod 1, or both the fixed capacitor and the variable capacitor are connected in parallel to the feed rod 1.

[0048] In one feasible embodiment, the capacitor of capacitor structure C can be one or more of the following: fixed ceramic capacitor, vacuum variable capacitor, air variable capacitor, switched capacitor array, and structural distributed capacitor.

[0049] In one feasible embodiment, the capacitor structure C can be connected in parallel at one or more of the following locations on the feed rod 1: The feeder pole consists of an atmospheric section, a transition section, and a vacuum section.

[0050] Preferably, the capacitor structure C is connected in parallel in the atmospheric section of the feed rod.

[0051] The radio frequency feeding structure of the plasma chamber of the present invention significantly improves the vacuum side voltage by forming an LC parallel impedance transformation network consisting of a capacitor structure connected in parallel with the feeding rod and the parasitic inductance of the feeding rod itself, thereby improving the plasma ignition stability. In particular, it effectively improves the deficiencies of the ignition edge in the edge ignition state, significantly reduces ignition instability and matching delay, and ensures reliable gas breakdown and rapid plasma establishment in the edge region.

[0052] This invention achieves control of the electrode side (vacuum side) voltage according to the ignition state by adjusting the capacitance value of the capacitor structure connected in parallel with the feed rod. During plasma ignition, the voltage can be controllably increased, allowing the vacuum side voltage to break through the fixed clamping limitation of the prior art and reach a level sufficient to break down the gas, thereby solving the problem of limited performance of dynamic control of electrode side voltage.

[0053] This invention can maintain the stability of RF operation after ignition. By flexibly using fixed or variable capacitors, a high voltage can be quickly established using a fixed capacitor during the ignition stage to ensure reliable ignition, while a variable capacitor can be used for fine impedance matching during the stable deposition stage to maintain maximum power transmission efficiency. At the same time, by optimizing the impedance cancellation relationship between the power supply side and parasitic loads, unnecessary capacitor current loads are reduced, significantly improving process power and system operation stability.

[0054] Figure 2 This is a schematic diagram of one embodiment of the substrate processing apparatus of the present invention, as shown below. Figure 2 As shown, the substrate processing apparatus 100 includes a radio frequency power supply V, an impedance matching network (which can be disposed within the radio frequency power supply V to form a radio frequency power supply 20 with an impedance matching network), a radio frequency feeding structure 10, a plasma chamber 30, a gas spray section 40, and a substrate support section 50. The plasma chamber 30 has a processing space inside for processing the substrate; A substrate support 50 is disposed inside the plasma chamber 30 for placing the substrate; The gas spraying section 40 is configured to face the substrate support section 50 and is used to supply process gas to the substrate. Radio frequency power supply V provides radio frequency power to at least one of the gas spray section and the substrate support section to form plasma between the substrate support section and the gas spray section; An impedance matching network is used to match the plasma impedance during plasma formation; The radio frequency feeding structure 10 of the plasma chamber includes a feeding rod 1, a capacitor structure C connected in parallel with the feeding rod 1, a spray head 2 (as the upper electrode), an insulating ring 3, and an inner liner ring 4. The substrate support portion 50 within the plasma chamber 30 serves as the lower electrode. The RF power supply V and impedance matching network are used to generate RF power and perform impedance matching. Its output extends downward and is electrically connected to the upper end of the feed rod 1. The capacitor structure C is connected across the feed rod 1 and the grounded top cover of the plasma chamber 30, forming a parallel relationship with the feed rod 1. The lower end of the feed rod 1 extends downward and is electrically connected to the atmospheric side interface on the back of the spray head 2 (installed on the top cover of the plasma chamber 30), thereby introducing RF power into the body of the spray head 2. The insulating ring 3 (dielectric layer) is sandwiched between the outer periphery of the spray head 2 and the grounded cavity wall, electrically isolating the spray head 2 from the grounded cavity wall and achieving vacuum sealing. The inner liner ring 4 is located below the insulating ring 3 and surrounds the outer periphery of the spray head 2, and is installed close to the side wall of the plasma chamber 30. The spray head 2 serves as the upper electrode of the plasma chamber 30, and its lower surface extends into the interior of the plasma chamber 30, opposite to the lower electrode (substrate support 50, used to support the wafer) that is grounded below, forming a plasma discharge gap between them.

[0055] Figure 3 This is a circuit schematic diagram of an embodiment of the simulation circuit of the radio frequency feeding structure of the plasma chamber described in this invention, as shown below. Figure 3 As shown, the simulation circuit includes an RF power supply V, a first inductor L1, a capacitor structure C, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fifth capacitor C5, a second inductor L2, and a plasma load Zp. The first inductor L1 simulates the inductance of the feed rod 1; The first capacitor C1 simulates an insulating structure capacitor; The second capacitor, C2, simulates the stray capacitance of the structure. The third capacitor, C3, simulates a vacuum coupling capacitor. The fifth capacitor, C5, simulates the upper dielectric layer capacitor; The second inductor, L2, simulates the inductance of a vacuum-side transmission line.

[0056] This invention constructs a simulation circuit comprising a radio frequency power supply, a first inductor, a capacitor structure connected in parallel with the first inductor, and a plasma load consisting of a first capacitor, a second capacitor, a third capacitor, a fifth capacitor, a second inductor, and a plasma load. It utilizes the LC parallel impedance transformation network formed by the capacitor structure connected in parallel with the first inductor to change the amplitude and phase of the equivalent impedance on the power supply side. This allows the impedance to be conjugate-cancelled with the total parasitic capacitive load formed by the first and second capacitors at the node, thereby significantly reducing the total series impedance from the radio frequency power supply to the plasma load and improving the node voltage and main path current transmission efficiency. Thus, during the plasma ignition stage, the simulation yields and applies an inductively coupled plasma load. The capacitance value is smaller than the first simulated capacitance value, which significantly increases the vacuum-side voltage to a level sufficient to break down the gas in the edge region. This solves the problems of low maximum amplitude of vacuum-side voltage, insufficient ignition edge, unstable or delayed ignition in the prior art. At the same time, the state recovery time is shortened by rapidly establishing plasma through high voltage. In the plasma stable deposition stage, the second simulated capacitance value is obtained through simulation and adjusted to track the dynamic drift of plasma load impedance in real time. This achieves fine impedance matching and minimizes RF reflection power, thereby dynamically controlling the vacuum-side electrode voltage and maintaining maximum power transmission efficiency. This solves the problems of low process power and limited performance of dynamic control of electrode-side voltage.

[0057] The electrical connections of the components in the above simulation circuit are as follows: Figure 2 As shown: One end of the radio frequency power supply is grounded, and the other end is electrically connected to one end of the first inductor L1. The other end of the first inductor L1 is electrically connected to one end of the first capacitor C1, the second capacitor C2 and the third capacitor C3 respectively, and the other ends of the first capacitor C1 and the second capacitor C2 are grounded. The capacitor structure C is connected in parallel with the first inductor L1; The other end of the third capacitor C3 is electrically connected to one end of the fifth capacitor C5; The other end of the fifth capacitor C5 is electrically connected to one end of the second inductor L2; The other end of the second inductor L2 is electrically connected to one end of the plasma load; The other end of the plasma load is grounded.

[0058] In one feasible embodiment, the simulation circuit further includes a first resistor R1 that simulates the equivalent series resistance of the vacuum-side feed rod 1: One end of the first resistor R1 is electrically connected to the other end of the second inductor L2; The other end of the first resistor R1 is electrically connected to one end of the plasma load.

[0059] In one feasible embodiment, the simulation circuit further includes a fourth capacitor C4 for simulating the parasitic capacitance between the liner ring 4 of the plasma chamber 30 and the grounded cavity wall: One end of the fourth capacitor C4 is electrically connected to the other end of the third capacitor C3; The other end of the fourth capacitor C4 is grounded.

[0060] In one feasible embodiment, the simulation circuit further includes a third inductor L3 that simulates the parasitic inductance of the ground connection structure: One end of the third inductor L3 is electrically connected to the other end of the second inductor L2; The other end of the third inductor L3 is electrically connected to the other end of the second capacitor C2. In one feasible embodiment, the simulation circuit further includes the equivalent series resistance of the simulated second capacitor C2 branch: One end of the second resistor R2 is electrically connected to the other end of the second inductor L2; The other end of the second resistor R2 is electrically connected to the other end of the first capacitor C1.

[0061] In one feasible embodiment, the simulation circuit further includes a third resistor R3 that simulates the equivalent series resistance of the first capacitor C1 branch: One end of the third resistor R3 is electrically connected to the other end of the first capacitor C1; The other end of the third resistor R3 is grounded.

[0062] Several embodiments of the simulation circuit have been given above, but the present invention is not limited thereto. It can be any combination of the above-mentioned multiple electrical components, and may also include other electrical components of the simulated plasma chamber 30.

[0063] In a preferred embodiment, such as Figure 4 As shown: The simulation circuit includes: RF power supply, first inductor L1, capacitor structure C, first capacitor C1, second capacitor C2, third capacitor C3, fourth capacitor C4, fifth capacitor C5, second inductor L2, first resistor R1, plasma load, second inductor L2, second resistor R2 and third resistor R3: One end of the radio frequency power supply is grounded, and the other end is electrically connected to one end of the first inductor L1. The other end of the first inductor L1 is electrically connected to one end of the first capacitor C1, the second capacitor C2 and the third capacitor C3 respectively; The capacitor structure C is connected in parallel with the first inductor L1; The other end of the first capacitor C1 is electrically connected to one end of the third resistor R3, and the other end of the third resistor R3 is grounded. The other end of the second capacitor C2 is electrically connected to one end of the second resistor R2, and the other end of the second resistor R2 is electrically connected to one end of the third resistor R3; The other end of the third capacitor C3 is electrically connected to one end of the fourth capacitor C4 and the fifth capacitor C5, respectively. The other end of the fourth capacitor C4 is electrically connected to one end of the third inductor L3, and the other end of the third inductor L3 is electrically connected to the other end of the second capacitor C2. The other end of the fifth capacitor C5 is electrically connected to one end of the second inductor L2, and the other end of the second inductor L2 is electrically connected to one end of the first resistor R1. The other end of the first resistor R1 is electrically connected to one end of the plasma load Zp; The other end of the plasma load Zp is grounded.

[0064] This invention constructs a simulation circuit comprising a radio frequency power supply, a first inductor, a capacitor structure connected in parallel with the first inductor, and a second inductor, a first resistor, a second resistor, a third resistor, a third inductor, and a plasma load. The LC parallel impedance transformation network formed by the capacitor structure and the first inductor alters the amplitude and phase of the equivalent impedance on the power supply side, enabling it to conjugate and cancel out the total parasitic capacitive load formed at the node by the first, second, and fourth capacitors. This significantly reduces the total series impedance from the radio frequency power supply to the plasma load, improving the node voltage and main path current transmission efficiency. Specifically, the fourth capacitor simulates the parasitic capacitance between the inner ring and the grounding cavity wall; the third inductor simulates the parasitic inductance of the grounding connection structure; the second and third resistors simulate the equivalent series losses of the stray branches and the insulating branch of the structure, respectively; and the first resistor simulates the equivalent series resistance of the vacuum-side feed rod. The introduction of these parasitic elements enhances the simulation circuit. This method can more accurately reflect the impedance distribution, power attenuation mechanism, and parasitic effects of the grounding loop in the actual power supply structure, thereby more accurately determining the first simulated capacitance value of the capacitor structure in the plasma ignition stage and the second simulated capacitance value in the stable deposition stage, avoiding capacitance deviation and mismatch caused by simplified models. Based on the capacitance value of the capacitor structure determined by this accurate simulation, the vacuum side voltage is significantly increased to a level sufficient to break down the gas in the edge region during the plasma ignition stage, solving the problems of low maximum amplitude of vacuum side voltage, insufficient ignition edge, unstable ignition, or delay in the prior art. At the same time, the state recovery time is significantly shortened by rapidly establishing plasma through high voltage. In the stable plasma deposition stage, by adjusting the capacitance value of the capacitor structure to the second simulated capacitance value, the dynamic drift of the plasma load impedance is accurately tracked, achieving fine impedance matching and minimizing RF reflection power. This enables precise dynamic control of the vacuum side electrode voltage, solving the problems of low process power and limited dynamic control of electrode side voltage performance.

[0065] This invention also provides a vapor deposition method, comprising: The vacuum-side voltage during the plasma ignition stage is adjusted by a capacitor structure connected in parallel with the feed rod. The impedance matching state during the stable plasma deposition stage is adjusted by a capacitor structure connected in parallel with the feed rod.

[0066] The vapor deposition method described in this invention systematically addresses multiple shortcomings of existing technologies through the timing coordination and capacitance linkage of the plasma ignition stage and the stable deposition stage. In the ignition stage, by connecting a capacitor structure in parallel to the feed rod, and utilizing the LC parallel impedance transformation network formed by the capacitor structure and the parasitic inductance of the feed rod, the equivalent inductance on the power supply side and the total parasitic capacitive load formed by the parasitic capacitance at the edge of the insulating ring / dielectric layer at the node, the stray capacitance at the vacuum coupling interface, and the coupling capacitance of the support structure are conjugately canceled out. This significantly reduces the total series impedance from the RF power supply to the vacuum side electrode, thereby greatly increasing the vacuum side voltage to a level sufficient to break down the gas in the edge region, ensuring reliable edge ignition and rapid plasma establishment. This directly solves the problems of low maximum vacuum side voltage amplitude, insufficient ignition edge, and unstable or delayed ignition. This high-voltage rapid ignition mechanism also significantly compresses the time required for... The transition time from transient to steady state provides favorable initial plasma conditions for the subsequent stable deposition stage. After entering the stable deposition stage, based on the low impedance transmission foundation established by the aforementioned LC network, the capacitance value of the capacitor structure is further adjusted to track the dynamic drift of the plasma load impedance in real time, achieving fine impedance matching and minimizing RF reflection power, thereby dynamically controlling the vacuum side electrode voltage and maintaining maximum power transmission efficiency. The synergistic effect of the two stages is manifested in the following ways: the rapid establishment of high voltage in the ignition stage not only eliminates the problem of slow state recovery but also provides a stable plasma environment for the steady state stage. In turn, the fine matching in the steady state stage maintains the continuous stability of the plasma, avoiding the vicious cycle of needing to undergo ignition delay again after the plasma is extinguished due to impedance mismatch. Ultimately, the problems of low process power and limited dynamic control of electrode side voltage performance are systematically solved.

[0067] In one feasible embodiment, the vapor deposition method further includes: The first simulated capacitance value of the capacitor structure C during the plasma ignition stage and the second simulated capacitance value during the plasma stable deposition stage were obtained by simulation circuit simulation. Plasma ignition is performed using a capacitance value of capacitor structure C that is not less than the first simulated capacitance value. Impedance matching control during the steady-state deposition stage using the second simulated capacitance value as a base value. In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0068] To illustrate the technical effects of the present invention, the following embodiments and comparative examples were provided: Example: The vapor deposition method in this embodiment includes: use Figure 4 The simulation circuit shown simulates the radio frequency feed structure of the plasma chamber: The RF power supply voltage is 100V; the inductance of the first inductor is 120nH; the capacitance of the first capacitor is 127.3pF; the capacitance of the second capacitor is 231.23pF; the capacitance of the third capacitor is 63.5pF; the capacitance of the fourth capacitor is 11.87pF; the capacitance of the fifth capacitor is 3nF; the inductance of the second inductor is 350nH; the resistance of the first resistor is 524mOhm; the inductance of the third inductor is 3nF; the resistance of the second resistor is 80mOhm; and the resistance of the third resistor is 100mOhm.

[0069] The simulation results are as follows: Figure 5 As shown, when the capacitance of the capacitor structure is 300 pF, the vacuum side voltage during plasma ignition reaches as high as 229.4 V.

[0070] A 300 pF capacitor structure is used in the substrate processing device, and the vacuum side voltage is 230V during plasma ignition.

[0071] Comparative example: The vapor deposition method in this comparative example is similar to that in Example 1, except that the capacitor structure connected in parallel with the first inductor is removed. The simulation results show that the vacuum side voltage is 188.28V when the plasma is ignited; the actual results show that the vacuum side voltage is 188V when the plasma is ignited in the substrate processing device.

[0072] As can be seen from the comparison between the embodiments and the comparative examples, the present invention, by connecting a 300 pF capacitor in parallel at both ends of the feed rod, significantly increases the vacuum side voltage during plasma ignition from 188 V in the prior art (Comparative Example 1) to 230 V, an increase of approximately 22.3%. Furthermore, the simulation result (229.4 V) highly matches the actual test result (230 V), fully verifying the accuracy of the simulation circuit and the effectiveness of the technical solution. Based on this comparison, the present invention has at least the following beneficial effects: Regarding improvements in ignition performance: The significant increase in vacuum-side voltage ensures that the gas in the edge region can be reliably broken down, thereby improving the problem of insufficient ignition edge under edge ignition conditions, effectively reducing ignition instability and matching delay, and making plasma ignition faster and more reliable.

[0073] Regarding voltage controllability: It breaks through the bottleneck of the vacuum side voltage being limited to 188 V in the existing technology, and realizes the controllable improvement of the electrode side (vacuum side) voltage, enabling the power supply structure to dynamically adjust the vacuum side voltage according to the ignition state, thus solving the problem of limited performance of the existing technology in dynamically controlling the electrode side voltage.

[0074] Regarding operational stability and power transmission efficiency: a higher vacuum-side voltage facilitates rapid plasma establishment, significantly shortens the recovery time from ignition transient to stable discharge, and makes the RF operation state after ignition more stable; at the same time, the LC parallel impedance transformation network formed by the capacitor structure and the parasitic inductance of the feed rod reduces the total series impedance from the RF power supply to the vacuum-side electrode, improves the transmission efficiency of RF power to the plasma load, and thus solves the problem of low process power.

[0075] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. The optional embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the embodiments of the present invention. These embodiments are selected and specifically described to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention.

Claims

1. A radio frequency feeding structure for a plasma chamber, comprising a feeding rod, characterized in that, The radio frequency feeding structure also includes a capacitor structure: The capacitor structure includes at least one capacitor connected in parallel with the feed rod; The capacitor is used to adjust the voltage of the feed rod during plasma ignition.

2. The radio frequency feeding structure for the plasma chamber according to claim 1, characterized in that, The capacitor structure includes a fixed capacitor and / or a variable capacitor.

3. The radio frequency feeding structure for the plasma chamber according to claim 2, characterized in that, The capacitor structure includes a fixed capacitor and a variable capacitor connected in parallel. The fixed capacitor provides a base capacitance during plasma ignition, and the variable capacitor is used to adjust the vacuum-side voltage after plasma ignition.

4. The radio frequency feeding structure of the plasma chamber according to claim 3, characterized in that, The capacitor structure also includes a switch control, which is electrically connected to the fixed capacitor and the variable capacitor respectively, to control the fixed capacitor and the variable capacitor to be connected in parallel to the feed rod simultaneously or at different times.

5. The radio frequency feeding structure for the plasma chamber according to claim 1, characterized in that, The capacitor structure is connected in parallel at one or more locations below the feeder pole: The feeder pole consists of an atmospheric section, a transition section, and a vacuum section.

6. The radio frequency feeding structure for the plasma chamber according to claim 5, characterized in that, The capacitor structure is connected in parallel to the atmospheric section of the feeder pole.

7. The radio frequency feeding structure for the plasma chamber according to claim 2, characterized in that, The capacitor structure includes at least one fixed capacitor or variable capacitor connected in parallel with the feed rod.

8. The radio frequency feeding structure of the plasma chamber according to claim 7, characterized in that, The capacitor structure also includes a switch control, which controls the timing of multiple fixed capacitors connected in parallel with the feed rod; or, the switch control controls the timing of multiple variable capacitors connected in parallel with the feed rod.

9. The radio frequency feeding structure for the plasma chamber according to claim 1, characterized in that, The capacitance value of the capacitor structure is determined based on radio frequency parameters, plasma physical characteristics, process requirements, and equipment structure. The radio frequency parameters include one or more of the following: operating frequency, rated output power and reflected power threshold of the radio frequency power supply, and dynamic variation range of plasma load impedance. The plasma physical characteristics include one or more of the following: breakdown voltage threshold of process gas, plasma steady-state equivalent resistance, plasma sheath capacitance, impedance jump amplitude, and response time constant. The process requirements include one or more of the following: target vacuum side voltage, chamber process pressure, thin film deposition rate, and power level. The equipment structure includes one or more of the following: geometric length and cross-sectional area of ​​the feed rod, coaxial distributed capacitance between the feed rod and the grounding cavity wall, dielectric constant and thickness of the insulating ring / dielectric layer, coverage area and installation position of the inner liner ring, and radial dimensions of the edge ring / focusing ring.

10. A substrate processing apparatus, comprising: The plasma chamber has a processing space inside for processing the substrate; A substrate support is disposed inside the plasma chamber for placing the substrate; A gas spraying section is configured to face the substrate support section and is used to supply process gas to the substrate. A radio frequency power supply provides radio frequency power to at least one of the gas spray section and the substrate support section to form plasma between the substrate support section and the gas spray section; And an impedance matching network for matching plasma impedance during plasma formation. Its characteristic is that it further includes: The radio frequency feeding structure of the plasma chamber according to any one of claims 1 to 9 is used to regulate the ignition of the plasma formed in the processing space of the plasma chamber.

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