Electrode device, semiconductor process equipment and voltage regulation and control method

Abstract

The invention provides an electrode device, semiconductor process equipment and a voltage regulation and control method, the electrode device comprises an electrode piece and a voltage regulation and control device, the electrode piece is connected with a radio frequency device of the semiconductor process equipment, and the radio frequency device is used for feeding radio frequency into the electrode piece; the voltage regulation and control device comprises a measuring unit and a direct-current power supply; the measuring unit is used for measuring the direct-current bias voltage of the electrode piece; the direct-current power supply is electrically connected with the measuring unit and used for applying correction bias voltage opposite to the polarity of the direct-current bias voltage to the electrode piece according to the direct-current bias voltage. Abnormal discharge in a cavity of semiconductor process equipment is often caused by direct current bias voltage acting on an electrode piece. The measuring unit can measure the magnitude of the direct-current bias voltage and output the correction bias voltage with the polarity opposite to that of the direct-current bias voltage to the electrode piece, the numerical value of the direct-current bias voltage on the electrode piece is reduced, and then the risk of abnormal discharge caused by too high direct-current bias voltage is reduced.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing, and more specifically, to an electrode device, semiconductor process equipment, and voltage regulation method. Background Technology

[0002] Plasma-enhanced atomic layer deposition (PEALD) technology has precise thin film thickness control capabilities. Products processed using PEALD technology have advantages such as good film quality, uniformity, and step coverage. Therefore, PEALD technology has become an important thin film deposition process technology.

[0003] Semiconductor devices using PEALD technology, or PEALD equipment, require the introduction of specific reactive gases into the cavity while simultaneously providing radio frequency (RF) power to generate the plasma necessary for deposition. To improve the quality of the deposited thin film and expand its applications, PEALD equipment necessitates increased RF energy, but this also increases the risk of abnormal discharges within the cavity. Abnormal discharges can trigger localized arcing or thin film breakdown, severely impacting cavity stability and process results.

[0004] Therefore, how to reduce the risk of abnormal discharge is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This application aims to solve at least one of the technical problems existing in the prior art, and proposes an electrode device, semiconductor process equipment and voltage regulation method that can reduce the risk of abnormal discharge.

[0006] To achieve the purpose of this application, an electrode device is provided for semiconductor process equipment, comprising an electrode element and a voltage regulation device, wherein,

[0007] The electrode is connected to the radio frequency device of the semiconductor process equipment, and the radio frequency device is used to feed radio frequency to the electrode.

[0008] The voltage regulation device includes a measurement unit and a DC power supply. The measurement unit is used to measure the DC bias voltage of the electrode. The DC power supply is electrically connected to the measurement unit and is used to apply a corrective bias voltage with opposite polarity to the DC bias voltage to the electrode according to the DC bias voltage.

[0009] In some embodiments, the electrode is a spray head.

[0010] In some embodiments, the voltage regulation device further includes a connection component disposed on the electrode and connected to the DC power supply for applying the corrected bias voltage to the electrode.

[0011] The connection assembly includes a conductive connector and a conductive mesh. The conductive mesh is disposed near the lower surface of the spray head, and the conductive connector connects the DC power supply to the conductive mesh.

[0012] In some embodiments, the conductive mesh includes a plurality of conductive rings and conductive connecting strips connecting each of the conductive rings. Each of the conductive rings is concentrically arranged with the spray head and distributed from the center of the spray head to the edge. The spray head has a plurality of spray holes, and the conductive rings are arranged to avoid the spray holes.

[0013] In some embodiments, the lower surface of the spray head includes a first preset region near the edge and a second preset region near the center. At least two conductive rings are distributed in both the first preset region and the second preset region. The spacing between the conductive rings in the first preset region is smaller than the spacing between the conductive rings in the second preset region.

[0014] In some embodiments, the voltage regulation device further includes a filtering module located between the DC power supply and the connection component, for preventing radio frequency signals on the electrodes from being conducted to the DC power supply.

[0015] In some embodiments, the conductive connector is embedded in the spray head, and the conductivity of the conductive connector is greater than the conductivity of the electrode.

[0016] In some embodiments, the conductive mesh is embedded near the lower surface of the spray head.

[0017] In some embodiments, a shielding cover is further included, the shielding cover being used to cover the reaction chamber of the semiconductor process equipment, the DC power supply being installed on the outside of the shielding cover, and the filter module being installed on the inside of the shielding cover.

[0018] This application also provides a semiconductor process apparatus, including a reaction chamber, a radio frequency device, and an electrode device as described above, wherein the electrode device is installed in the reaction chamber, and the radio frequency device is used to feed radio frequency to the electrode element of the electrode device;

[0019] The radio frequency device includes a radio frequency power supply and a matching unit. The radio frequency power supply is connected to the matching unit, and the matching unit is connected to the electrode through a radio frequency connector. The measurement unit is connected to the matching unit.

[0020] This application also provides a voltage regulation method for any of the electrode devices described above, comprising:

[0021] Obtain the DC bias voltage;

[0022] The corrected bias voltage is determined based on the DC bias voltage;

[0023] The corrected bias voltage is applied to the electrode.

[0024] In some embodiments, after measuring the DC bias voltage, the method further includes:

[0025] Compare the DC bias voltage with the bias threshold;

[0026] If the DC bias voltage is greater than the bias threshold, then the step of determining the corrected bias voltage based on the DC bias voltage is performed;

[0027] If the DC bias voltage is less than the bias threshold, repeat the step of measuring the DC bias voltage.

[0028] In some embodiments, after applying the corrected bias voltage to the electrode, the method further includes:

[0029] Repeat the steps of measuring the DC bias voltage;

[0030] Determining the corrected bias voltage based on the DC bias voltage includes:

[0031] The new corrected bias is the sum of the original corrected bias and the bias increase.

[0032] In some embodiments, the bias increase is the difference between the DC bias voltage and the bias threshold voltage or half of the difference.

[0033] This application has the following beneficial effects:

[0034] This application provides an electrode device for semiconductor process equipment, comprising an electrode element and a voltage regulation device, wherein...

[0035] The electrode is connected to the radio frequency (RF) device of the semiconductor process equipment, and the RF device is used to feed RF to the electrode.

[0036] The voltage regulation device includes a measuring unit and a DC power supply. The measuring unit is used to measure the DC bias voltage of the electrode. The DC power supply is electrically connected to the measuring unit and is used to apply a corrective bias voltage with the opposite polarity to the DC bias voltage to the electrode according to the DC bias voltage.

[0037] Abnormal discharges within semiconductor process equipment chambers are often caused by DC bias voltage applied to the electrodes. The measurement unit can measure the magnitude of the DC bias voltage and output a corrective bias voltage with the opposite polarity to the DC bias voltage to the electrodes, reducing the value of the DC bias voltage on the electrodes and thus reducing the risk of abnormal discharges caused by excessive DC bias voltage.

[0038] This application also provides a semiconductor process apparatus including the above-described electrode device and a voltage regulation method for the above-described electrode device, which has the aforementioned advantages. Attached Figure Description

[0039] Figure 1 The voltage-time curves of the spray head in the PEALD chamber before and after being affected by a DC bias voltage;

[0040] Figure 2 This is a schematic diagram showing the accumulation of charge on the lower surface of the thin film.

[0041] Figure 3 A schematic diagram of the structure of a semiconductor process apparatus provided in a specific embodiment of this application;

[0042] Figure 4 for Figure 3 A schematic diagram showing the connection between the DC power supply and the main body of the spray head;

[0043] Figure 5 for Figure 3 A schematic diagram showing the connection between the DC power supply and the sprinkler head.

[0044] Figure 6 for Figure 3 A bottom view of the central sprinkler head;

[0045] Figure 7 Voltage-time curves before and after adjustments to semiconductor process equipment;

[0046] Figure 8 A graph showing the trend of DC bias voltage variation in semiconductor process equipment;

[0047] Figure 9 A flowchart illustrating a specific embodiment of the voltage regulation method provided in this application;

[0048] Figure 10 A flowchart of another specific embodiment of the voltage regulation method provided in this application;

[0049] Figure 11 This is a flowchart of a voltage regulation method provided in another specific embodiment of this application.

[0050] in, Figures 1 to 11 The attached figures are labeled as follows:

[0051] 1. RF power supply; 2. Matching unit; 3. Measurement unit; 4. RF connector; 5. Gas supply pipe; 6. Shielding cover; 7. Ceramic insulating block; 8. Spray head; 81. Main body; 82. Spray head; 83. Insulating film; 9. Ceramic ring; 10. Constraint ring; 11. Base; 12. Plasma reaction zone; 13. Reaction chamber; 14. Filter module; 15. DC power supply; 16. Connecting assembly; 161. Conductive connector; 162. Conductive mesh; 163. Conductive ring; 164. Conductive connecting strip. Detailed Implementation

[0052] To enable those skilled in the art to better understand the technical solutions of this application, the electrode device, semiconductor process equipment and voltage regulation provided in this application will be described in detail below with reference to the accompanying drawings.

[0053] In semiconductor process equipment, the spray head is part of the upper electrode. The radio frequency (RF) device is connected to the spray head and feeds RF power to it, providing energy to the semiconductor process equipment. The electrode voltages of the semiconductor process equipment include the peak-to-peak value of the spray head-to-ground potential difference Vpp and the DC bias voltage Vdc. During the process of plasma ignition and stabilization within the semiconductor process equipment, both the peak-to-peak value of the spray head-to-ground potential difference Vpp and the DC bias voltage Vdc will change in amplitude. For example... Figure 1 As shown, at the instant the radio frequency device applies power to the sprinkler head, the potential difference between the sprinkler head and ground is as follows: Figure 1 As shown in (A), due to the periodic variation of RF power, the peak-to-peak value Vpp1 can be divided into the peak value Vp1+ of the positive half-cycle and the peak value Vp1- of the negative half-cycle. At this time, the gas inside the cavity is not broken down, the amplitudes of Vp1- and Vp1+ are equal, and the amplitude of the DC bias voltage is 0. When the gas inside the cavity is broken down and plasma stability is achieved, a DC bias voltage Vdc-2 will be formed inside the semiconductor process equipment due to the influence of gas flow rate, pressure, and the effective area of ​​the spray head and base 11 during the reaction. Figure 1 As shown in (B), under the influence of the DC bias voltage Vdc-2, |Vp2+|

[0054] >|Vp2-|, meaning the absolute value of the peak value in the positive half-cycle is greater than the absolute value of the peak value in the negative half-cycle. The DC bias voltage Vdc-2 is proportional to the applied RF power; the higher the RF power, the larger the amplitude of the resulting DC bias voltage Vdc-2. When the semiconductor process equipment is turned on, the spray head is under positive voltage due to the presence of the positive DC bias voltage Vdc-2.

[0055] To improve the stability of the chamber, semiconductor processing equipment performs a pre-deposit process, which involves depositing an insulating film, such as a silicon oxide film, into the chamber to cover the surface of the reaction components. An insulating film is also formed on the lower surface of the spray head. The thickness of this insulating film is typically tens of nanometers or more. Figure 2As shown, due to the presence of an alternating electric field within the semiconductor process equipment, electrons with very small mass will move to the lower surface of the insulating film and accumulate on the lower surface, forming a local negative potential, which will create a voltage difference ΔV on both sides of the insulating film.

[0056] As process requirements increase, semiconductor process equipment employs higher radio frequency (RF) power, leading to a corresponding increase in the DC bias voltage (Vdc) and the voltage difference (ΔV) across the insulating film. Furthermore, during the process, ion bombardment of the insulating film occurs. Prolonged bombardment continuously damages the local physicochemical structure of the insulating film, resulting in a decrease in its withstand voltage. When the voltage difference (ΔV) across the insulating film exceeds a certain limit, local breakdown occurs, causing destructive abnormal discharges (such as arc discharges), generating and releasing a large number of particles and free electrons. At this point, the impedance of the abnormal discharge region within the cavity becomes very small due to electrical breakdown, and the current within the cavity increases and flows through this region. Because of the increased total current, the peak-to-peak value of the electrode voltage decreases significantly. Semiconductor process equipment experiencing abnormal discharges, due to the reduced peak-to-peak value of the electrode voltage, increased local RF current density, and the occurrence of insulating film breakdown, will develop severe particle and process film quality problems.

[0057] Excessive DC bias voltage can also occur at the lower electrode. The diameter of the substrate is usually larger than that of the wafer. When the wafer is placed on the upper surface of the substrate, a portion of the outer edge of the upper surface of the substrate is exposed in the cavity. Excessive DC bias voltage can also cause the insulating film in the exposed area to break down.

[0058] The electrode device provided in this application is applied to semiconductor process equipment. The electrode device includes an electrode element and a voltage regulation device. The electrode element is connected to the radio frequency (RF) device of the semiconductor process equipment, which feeds RF signals to the electrode element. The voltage regulation device includes a measurement unit and a DC power supply. The measurement unit is used to measure the DC bias voltage of the electrode element. The DC power supply is electrically connected to the measurement unit and is used to apply a corrective bias voltage with opposite polarity to the DC bias voltage to the electrode element according to the DC bias voltage.

[0059] As described above, radio frequency (RF) feed is applied to the electrode, which generates a DC bias voltage during the manufacturing process. Measurement unit 3 measures this DC bias voltage and can be a voltage sensor or similar device. The DC power supply 15 may include a power supply body and a control component (not shown in the figure). The control component is electrically connected to measurement unit 3 and determines the negative bias voltage based on the DC bias voltage. The power supply body, connected to the electrode, applies a corrective bias voltage to the electrode. This corrective bias voltage reduces the DC bias voltage, thereby reducing the voltage difference ΔV across the insulating film 83, lowering the insulation film 83's losses, and reducing the risk of abnormal discharges such as insulation film 83 breakdown. The control component can be a microcontroller (MCU) or an industrial computer.

[0060] The value of the corrective bias voltage usually changes with the magnitude of the DC bias voltage; the larger the DC bias voltage, the larger the corrective bias voltage; the smaller the DC bias voltage, the smaller the corrective bias voltage.

[0061] The electrode device provided in this application can be the upper electrode or the lower electrode of a semiconductor process equipment. When the electrode device is the upper electrode, the electrode element can be a spray head 8; when the electrode device is the lower electrode, the electrode element can be a base. This application uses the upper electrode as an example for illustration. In semiconductor processing, the base is usually used to support the wafer, and the spray head 8 is used to deliver process gas into the reaction chamber 13. Radio frequency loading and corrective bias loading are applied to the spray head 8, which can avoid direct voltage changes to the base and help improve process stability. For the case where the electrode element is a base, please refer to the embodiment where the electrode element is a spray head, which will not be described in detail here.

[0062] like Figure 3 As shown, the semiconductor process equipment also includes a reaction chamber 13, a base 11, a radio frequency device, a ceramic ring 9, and a confinement ring 10. A spray head 8 is disposed within the reaction chamber 13 and connected to it via the ceramic ring 9. Exemplarily, the inner ring of the ceramic ring 9 is connected to the spray head 8, and the outer ring is connected to the reaction chamber 13. The base 11 is located below the spray head 8 and is used to support the wafer. The confinement ring 10 surrounds the outer periphery of the base 11 and can be made of insulating materials such as ceramic. Process gases are confined to flow between the confinement ring 10, the base 11, and the spray head 8. A plasma reaction zone 12 is located between the confinement ring 10, the base 11, and the spray head 8. The process gases generate plasma in the plasma reaction zone 12, which then reacts with the wafer to complete wafer processing.

[0063] The spray head 8 is used to spray process gas into the plasma reaction zone 12. An RF device is used to feed RF signals into the spray head 8, and the base 11 is grounded, acting as the lower electrode. An electric field is formed between the spray head 8 and the base 11. Under the influence of this electric field, the process gas in the plasma reaction zone 12 ionizes to form plasma, which then reacts with the wafer surface on the base 11. An insulating film 83 can be provided on the lower surface of the spray head 8 to reduce plasma corrosion of the spray head 8.

[0064] After the radio frequency and corrective bias voltages are superimposed, it is necessary to ensure that the DC bias voltage of the spray head 8 is non-negative. Since a small DC bias voltage will not cause the insulating film 83 to break down, the user can set a bias voltage threshold. If the DC bias voltage is less than the bias voltage threshold, the DC power supply 15 does not need to output a corrective bias voltage.

[0065] Optionally, the control component can issue an alarm when the DC bias voltage exceeds the bias threshold, indicating that the DC bias voltage is too high.

[0066] Optional, such as Figure 3 As shown, the electrode device also includes a shielding cover 6, which is installed above the reaction chamber 13. The radio frequency (RF) device may include an RF power supply 1 and a matching device 2. The RF power supply 1 and the matching device 2 are connected, and both the RF power supply 1 and the matching device 2 are located outside the shielding cover 6. The matching device 2 is connected to the spray head 8 via an RF connector 4. RF signals are applied to the spray head 8 through the RF connector 4. The RF connector 4 may be a conductive component such as a metal strip.

[0067] In some embodiments, the voltage regulation device further includes a filter module 14, which is located between the DC power supply 15 and the spray head 8, and is used to filter out radio frequency signals on the spray head 8.

[0068] Because the radio frequency device loads radio frequency onto the spray head 8, and the connecting component 16 is electrically connected to the spray head 8, the radio frequency can also be conducted along the connecting component 16 to the DC power supply 15, affecting the power supply body and control components of the DC power supply 15. The filtering module 14 is located between the DC power supply 15 and the connecting component 16, and can filter out the radio frequency, preventing its transmission to the DC power supply 15, thus protecting the power supply body and control components. For example, Figure 3 The intermediate filtering module 14 uses an LC circuit for filtering. Other filtering circuits can also be used in the filtering module 14, which are not limited here.

[0069] Optionally, the DC power supply 15 can be installed on the outside of the shielding cover 6, and the filter module 14 can be installed on the inside of the shielding cover 6. The filter module 14 applies a DC corrective bias to the spray head 8 through the connection component 16.

[0070] Optionally, the spray head 8 includes a body 81 and a nozzle 82. The body 81 is connected to a gas supply pipe 5, and the nozzle 82 includes multiple spray holes. The body 81 is used to distribute the process gas supplied by the gas supply pipe 5 to each spray hole.

[0071] like Figure 3 As shown, the diameter of the main body 81 is larger than the diameter of the nozzle 82, and the nozzle 82 is coaxially arranged with the main body 81. The lower surface of the main body 81 has an overlapping surface surrounding the outer periphery of the nozzle 82. The overlapping surface is used for overlapping and mating with the ceramic ring 9.

[0072] The main body 81 can be equipped with a flow equalization cavity or flow equalization channel, etc. The gas supply pipe 5 is connected to the main body 81 by a ceramic insulating block 7, which has a connecting channel that connects the gas supply pipe 5 to the interior of the main body 81. The ceramic insulating block 7 can prevent the current in the spray head 8 from being conducted into the gas supply pipe 5. Of course, the insulating block between the spray head 8 and the gas supply pipe 5 can also be made of other materials, which is not limited here. The spray holes of the spray head 82 are connected to the flow equalization cavity or flow equalization channel or other structures inside the main body 81. After the process gas is redistributed within the main body 81, it is sprayed out from the spray holes, resulting in a more uniform concentration of process gas sprayed from each spray hole.

[0073] The voltage regulation device also includes a connection assembly 16, which is disposed on the spray head 8 and connected to the DC power supply 15 for applying a corrective bias voltage to the spray head 8. The connection assembly 16 includes a conductive connector 161 and a conductive mesh 162. The conductive mesh 162 is embedded near the lower surface of the spray head 82, and the conductive connector 161 connects the DC power supply 15 to the conductive mesh 162.

[0074] like Figure 4 As shown, a conductive connector 161 is disposed in the spray head 8 and extends to the lower surface of the spray head 8, and is connected to a conductive mesh 162 located near the lower surface of the spray head 8. A corrective bias voltage can be transmitted from the conductive connector 161 to the conductive mesh 162. Both the conductive connector 161 and the conductive mesh 162 can be made of metal, such as copper or silver, and the conductive connector 161 can specifically be a metal strip.

[0075] Optionally, the conductive connector 161 is embedded in the spray head 8. For example... Figure 4 As shown, the conductive connector 161 is positioned near the edge of the spray head 8, avoiding structures such as the flow equalization cavity or flow equalization channel within the main body 81. The conductive connector 161 is embedded in the spray head 8, which improves the strength of the connection. Furthermore, the conductivity of the conductive connector 161 is greater than that of the spray head 8, allowing current to flow along the conductive connector 161 into the conductive mesh 162. Of course, the conductive connector 161 can also be connected to the spray head 8 in other ways. For example, the conductive connector 161 may not be embedded in the spray head 8, but rather located outside the spray head 8 and connected independently to the conductive mesh 162; this is not a limitation.

[0076] In actual PEALD processes, the temperatures of the upper and lower electrodes are often quite high, sometimes reaching 390°C. During radio frequency energy transmission, most of the radio frequency current concentrates on the lower surface of the spray head 8 due to the skin effect, typically flowing within a depth of tens of micrometers. Furthermore, the spray head 8 is also subject to heat conduction from the base 11. These factors cause expansion and deformation at the edges of the spray head 8, including its lower surface, thus affecting the voltage distribution.

[0077] like Figure 5 As shown, the conductive mesh 162 is located near the lower surface of the spray head 8, outputting a corrective bias voltage to the spray head 8. The corrective bias voltage and the radio frequency work together on the spray head 8 to reduce the DC bias voltage of the spray head 8 relative to ground potential difference.

[0078] In this embodiment, the conductive mesh 162 on the lower surface of the spray head 8 improves the distribution of the corrective bias voltage on the lower surface of the spray head 82. If only the corrective bias voltage is applied to the spray head 8, although the DC bias voltage can be reduced, the lower surface of the spray head 8 often suffers from uneven voltage distribution, affecting the uniformity of plasma distribution. This embodiment, by applying the corrective bias voltage to the lower surface of the spray head 82 through the conductive mesh 162, enables the corrective bias voltage to be evenly distributed on the lower surface of the spray head 82, thereby making the voltage distribution on the lower surface of the spray head 82 more uniform. This improves the uniformity of plasma distribution within the chamber and enhances the processing accuracy of semiconductor equipment. Furthermore, as the lower surface of the spray head 8 expands due to heat, the conductive mesh 162 also undergoes corresponding deformation, thus offsetting the effect of the thermal expansion of the lower surface of the spray head 8 on the voltage distribution, resulting in a more uniform voltage distribution.

[0079] In some embodiments, the conductive mesh 162 includes a plurality of concentrically arranged conductive rings 163 and conductive connecting strips 164 connecting each conductive ring 163. Each conductive ring 163 is concentric with the lower surface of the nozzle 82 and is distributed from the center of the lower surface of the nozzle 8 to the edge. The conductive rings 163 are arranged to avoid the spray holes.

[0080] like Figure 6 As shown, the conductive ring 163 is concentrically arranged with the lower surface of the nozzle 82, thus enabling uniform upward DC voltage distribution along the nozzle 82. The lower surface of the nozzle 82 has a large area, and multiple conductive rings 163 are radially distributed along its lower surface, connected by conductive connecting strips 164, which in turn connect to conductive connectors 161. Corrective bias is supplied from the conductive connectors 161 to the conductive connecting strips 164, and then from the conductive connecting strips 164 to each conductive ring 163. The radial distribution of multiple conductive rings 163 along the lower surface of the nozzle 8 improves the uniformity of the radial DC voltage distribution. The conductive rings 163 and conductive connecting strips 164 are positioned to avoid obstructing the spray holes, preventing interference with process gas flow. The conductive rings 163 and conductive connecting strips 164 can be made of metallic materials, such as copper or silver. Figure 6 In the specific embodiment shown, the number of conductive connecting strips 164 is one, but the conductive mesh 162 may also have two or more conductive connecting strips 164, which is not limited here. In addition, the conductive mesh 162 may also adopt other structures, such as being composed of multiple regular hexagonal structures, which is not limited here.

[0081] Due to factors such as manufacturing errors and uneven temperature distribution, the degree of expansion deformation at the edge of the lower surface of the spray head 8 will vary. Although the overall equivalent DC bias value of the spray head 8 is reduced by the superposition of the applied DC voltage, uneven deformation will still cause problems such as different local impedances and uneven local DC voltage division.

[0082] Optionally, the lower surface of the spray head 8 includes a first preset area near the edge and a second preset area near the center. At least two conductive rings 163 are distributed in both the first and second preset areas. The spacing between the conductive rings 163 in the first preset area is smaller than the spacing between the conductive rings 163 in the second preset area.

[0083] Because of the edge effect caused by plasma discharge at the edge of the lower surface of the spray head 8, i.e., the electric field strength at the edge is higher than that within the geometric radius of the two electrodes, voltage unevenness is easily formed at the edge effect location. In this embodiment, the area where the edge effect occurs is divided into a first preset region, and the remaining area is divided into a second preset region. The conductive rings 163 need to be arranged more densely in the first preset region to enhance the corrective bias voltage applied by the DC power supply 15, more uniformly offset the DC bias voltage of the spray head 8 in the first preset region, and at the same time weaken the degree of bombardment of the first preset region by positively charged ions, thus slowing down the damage rate of the insulating film 83. Figure 6 In the specific embodiment shown, the first preset area has three conductive rings 163, and the second preset area has four conductive rings 163. The spacing between the three conductive rings 163 in the first preset area is small, while the spacing between the four conductive rings 163 in the second preset area is large. Of course, the number of conductive rings 163 in each area can be set according to process requirements and is not limited here.

[0084] Optionally, the conductive mesh 162 can be embedded in the nozzle 82, which can improve the firmness of the connection between the conductive mesh 162 and the nozzle 82, prevent the conductive mesh 162 from falling off, and at the same time prevent positive ions from bombarding the conductive mesh 162. Figure 5 As shown, the conductive mesh 162 should be placed as close as possible to the lower surface of the spray head 8, but still at a certain distance from the lower surface. This allows for uniform cancellation of the DC bias voltage and suppression of the bombardment of the lower surface of the spray head 8 by positive ions. However, due to limitations in the nesting process of the spray head 8, the conductive mesh 162 can be placed inside the spray head 82, approximately 2 mm away from the lower surface of the spray head 8. Of course, users can also use other processes to place the conductive mesh 162 in the spray head 8, and the distance between the conductive mesh 162 and the lower surface of the spray head 8 is not limited to this.

[0085] This application also provides a semiconductor process apparatus, including a reaction chamber, a radio frequency device, and an electrode device as described in any of the above embodiments. The electrode device is mounted on the reaction chamber, and the radio frequency device is used to feed radio frequency to the electrodes of the electrode device.

[0086] In some embodiments, the radio frequency device includes a radio frequency power supply 1 and a matching unit 2. The radio frequency power supply 1 is connected to the matching unit 2, the matching unit 2 is connected to the electrode via a radio frequency connector 4, and the measurement unit 3 is connected to the matching unit 2.

[0087] Matching unit 2 can be used to match loads such as RF power supply 1 and shower head 8, ensuring that the RF power is fully applied to the load. Measurement unit 3 is connected to matching unit 2 and acquires the RF voltage fed into shower head 8. It then calculates the DC bias voltage based on the voltage and transmits it to the control component. The control component controls the corrective bias value output by the voltage regulation device according to the magnitude of the DC bias voltage.

[0088] exist Figure 3 In the specific embodiment shown, the semiconductor process equipment also includes a base 11, a radio frequency device, a ceramic ring 9, and a constraint ring 10. A spray head 8 is disposed within the reaction chamber 13 of the semiconductor process equipment and connected to the reaction chamber 13 via the ceramic ring 9. Of course, the semiconductor process equipment can also have other structures, which are not limited here.

[0089] This application also provides a voltage regulation method for the electrode device in any of the above embodiments, comprising:

[0090] S100, Obtain DC bias voltage;

[0091] S200. Determine the corrective bias voltage based on the DC bias voltage;

[0092] S300, Apply corrective bias to spray head 8.

[0093] As mentioned above, the DC bias voltage can be measured by the measuring unit 3. The radio frequency device feeds radio frequency into the spray head 8. The voltage-time curve of the radio frequency is often sinusoidal, and the DC bias voltage can be the average value of the radio frequency voltage.

[0094] The measuring unit 3 transmits the measured DC bias voltage value to the control component of the DC power supply 15. The control component determines the value of the corrective bias voltage based on the DC bias voltage. The DC bias voltage is usually positive, and the absolute value of the corrective bias voltage is usually less than the DC bias voltage.

[0095] After the control component determines the value of the corrective bias voltage, the control power supply body applies the corrective bias voltage to the spray head 8 through the connection component 16. Since the absolute value of the corrective bias voltage is usually less than the DC bias voltage, the corrective bias voltage applied to the spray head 8 reduces the DC bias voltage to a safe range, thereby reducing the voltage difference ΔV across the insulating film 83, reducing the loss of the insulating film 83, and thus reducing the risk of abnormal discharge such as breakdown of the insulating film 83.

[0096] In some embodiments, after measuring the DC bias voltage, the method further includes:

[0097] Compare the DC bias voltage and the bias threshold.

[0098] In actual testing, it was found that the value of the DC bias voltage is positively correlated with the process duration. For example... Figure 7 As shown, if the initial DC bias voltage of the spray head 8 is V1, the DC bias voltage will gradually increase from V1 to V2 as the process time increases. There is a risk of the insulating film 83 being broken down only when the DC bias voltage exceeds a certain value. Therefore, this embodiment sets a bias voltage threshold, which can be determined based on the DC bias voltage required to break down the insulating film 83. For example, the bias voltage threshold is the DC bias voltage detected at maximum RF power when the process is stable, because the DC bias voltage is proportional to the RF power. When the DC bias voltage is less than the bias voltage threshold, the risk of the insulating film 83 being broken down is low; when the DC bias voltage is greater than the bias voltage threshold, the risk of the insulating film 83 being broken down is high.

[0099] If the DC bias voltage is greater than the bias threshold, then the step of determining the correct bias voltage based on the DC bias voltage is executed.

[0100] When luminescence occurs within the cavity, as... Figure 8 As shown in (C), the measuring unit 3 measures the DC bias voltage Vdc-A at the spray head 8. If this value is greater than the system-set bias threshold Spec Vdc, the DC power supply 15 outputs a corrective bias voltage to the spray head 8. Figure 8 As shown in (D), the value of the corrected bias voltage is Ve; Ve will be superimposed on the original DC bias voltage Vdc-A, that is, the entire voltage waveform will be shifted to the horizontal axis of the coordinate axis, which is equivalent to a new DC bias voltage Vdc-B. This reduces the value of the DC bias voltage, reduces the loss of the insulating film 83 caused by long-term process, and reduces the risk of serious abnormal discharge phenomena such as the breakdown of the insulating film 83.

[0101] If the DC bias voltage is less than the bias threshold, repeat the steps to measure the DC bias voltage.

[0102] The initial value of the DC bias voltage may be less than the bias threshold, such as... Figure 7As shown, since the DC bias voltage continuously increases with the process duration, the measurement unit 3 repeatedly measures the DC bias voltage. If it exceeds the bias threshold before the process ends, the DC power supply 15 will output a corrective bias voltage to the spray head 8. The DC power supply 15 applies the corrective bias voltage to the conductive mesh 162 of the spray head 8, which, when superimposed with the original DC bias voltage of the spray head 8, forms a new DC bias voltage. The new DC bias voltage value is reduced, which reduces the loss of the insulating film 83 and thus reduces the risk of abnormal discharge such as the breakdown of the insulating film 83.

[0103] In some embodiments, after applying the corrective bias to the spray head 8, the method further includes:

[0104] Repeat the steps of measuring the DC bias voltage;

[0105] During the process, the DC bias voltage continues to increase and may exceed the bias threshold again, posing a risk of breakdown of the insulating film 83. Measurement unit 3 repeatedly measures the DC bias voltage to detect when the DC bias voltage exceeds the bias threshold in a timely manner.

[0106] Determine the corrected bias voltage based on the DC bias voltage, including:

[0107] The new corrective bias is the sum of the original corrective bias and the increase in bias.

[0108] The bias voltage increase can be determined by the DC bias voltage. When the DC bias voltage exceeds the bias threshold again, the bias voltage increase is determined based on the DC bias voltage, and the sum of the bias voltage increase and the original corrective bias voltage is taken as the new corrective bias voltage. The DC power supply 15 outputs the new corrective bias voltage. Due to the increase in the new corrective bias voltage, after the new corrective bias voltage is applied to the spray head 8, the DC bias voltage on the spray head 8 can be reduced to below the bias threshold voltage, thereby reducing the risk of breakdown of the insulating film 83.

[0109] It should be noted that when the initial value of the DC bias voltage is less than the bias threshold, the original corrective bias voltage is zero. For example, at the start of the process, the DC bias voltage of the spray head 8 is less than the bias threshold. At this time, the DC power supply 15 does not need to output a corrective bias voltage, and the measurement unit 3 continues to measure the DC bias voltage. As the process progresses, the DC bias voltage exceeds the bias threshold. At this time, the DC power supply 15 needs to apply a corrective bias voltage to the spray head 8. Specifically, the control component calculates the bias increase value based on the DC bias voltage, and the sum of this bias increase value and the original corrective bias voltage (i.e., zero) is used as the new corrective bias voltage. The DC power supply 15 applies the new corrective bias voltage to the spray head 8, making the DC bias voltage less than the bias threshold. As the process continues, the DC bias voltage may exceed the bias threshold again. The control component calculates the bias increase value based on the DC bias voltage, and the sum of this bias increase value and the original corrective bias voltage (i.e., the previously applied corrective bias voltage) is used as the new corrective bias voltage. DC power supply 15 applies a new corrective bias voltage to spray head 8, causing the DC bias voltage to fall below the bias threshold voltage again. The process continues, and the voltage regulation method repeats the above process to keep the DC bias voltage below the bias threshold voltage.

[0110] Optionally, the bias increment is the difference between the DC bias voltage and the bias threshold voltage, or half of the difference.

[0111] Optional, such as Figure 10 As shown, the control component causes the power supply body of the DC power supply 15 to output a corrective bias voltage. This corrective bias voltage is fed into the conductive mesh 162 in the spray head 8 through the conductive connector 161. The output corrective bias voltage is |V| = Vdc - Spec / 2. The corrective bias voltage cannot exceed the original DC bias voltage, meaning the new DC bias voltage after superimposed on the spray head 8 cannot be less than zero. If the DC bias voltage is less than zero, the positive bias voltage of the spray head 8 cannot be used to suppress the bombardment of positive ions in the plasma against the insulating film 83. Although a higher corrective bias voltage can lower the voltage difference across the insulating film 83, if it causes the DC bias voltage to be less than zero, it will attract positive ions to bombard the insulating film 83. In this specific embodiment, the corrective bias voltage is usually superimposed on the original DC bias voltage of the spray head 8, and the new DC bias voltage is lowered to within the bias threshold and maintained at around 1 / 2 of the bias threshold to avoid abnormal discharge in the cavity. Because in actual discharge, the DC bias voltage of the spray head 8 will slowly increase with the increase of process time, adjusting it to 1 / 2 of the bias voltage threshold is to reserve a safe range for the electrode device to exceed the bias voltage threshold again. 1 / 2 of the bias voltage threshold comes from the measurement experience threshold, and users can also set it to other values, which are not limited here.

[0112] Optional, such as Figure 11As shown, the control component causes the DC power supply 15 to output a corrective bias voltage. This corrective bias voltage is fed into the conductive mesh 162 in the spray head 8 through the conductive connector 161. The output corrective bias voltage is |V| = Vdc - Spec. Even if the equivalent DC bias voltage value of the spray head 8 is maintained near the horizontal axis of the coordinate system, the increase in DC bias voltage caused by the process time will be detected, and the DC bias voltage will continue to be reduced to near the horizontal axis of the coordinate system under the control of the voltage control method.

[0113] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of this application, and this application is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this application, and these modifications and improvements are also considered to be within the scope of protection of this application.

Claims

1. An electrode device for use in semiconductor process equipment, characterized in that, Includes electrode components and voltage regulation devices, wherein, The electrode is connected to the radio frequency device of the semiconductor process equipment, and the radio frequency device is used to feed radio frequency to the electrode. The voltage regulation device includes a measurement unit and a DC power supply. The measurement unit is used to measure the DC bias voltage of the electrode. The DC power supply is electrically connected to the measurement unit and is used to apply a corrective bias voltage with opposite polarity to the DC bias voltage to the electrode according to the DC bias voltage.

2. The electrode device according to claim 1, characterized in that, The electrode component is a spray head.

3. The electrode device according to claim 2, characterized in that, The voltage regulation device further includes a connection component, which is disposed on the electrode and connected to the DC power supply, for applying the corrected bias voltage to the electrode. The connection assembly includes a conductive connector and a conductive mesh. The conductive mesh is disposed near the lower surface of the spray head, and the conductive connector connects the DC power supply to the conductive mesh.

4. The electrode device according to claim 3, characterized in that, The conductive mesh includes multiple conductive rings and conductive connecting strips connecting each conductive ring. Each conductive ring is concentrically arranged with the spray head and distributed from the center of the spray head to the edge. The spray head has multiple spray holes, and the conductive rings are arranged to avoid the spray holes.

5. The electrode device according to claim 4, characterized in that, The lower surface of the spray head includes a first preset area near the edge and a second preset area near the center. At least two conductive rings are distributed in both the first preset area and the second preset area. The spacing between the conductive rings in the first preset area is smaller than the spacing between the conductive rings in the second preset area.

6. The electrode device according to claim 3, characterized in that, The voltage regulation device further includes a filtering module located between the DC power supply and the connection component, which is used to prevent radio frequency on the electrode from being conducted to the DC power supply.

7. The electrode device according to claim 3, characterized in that, The conductive connector is embedded in the spray head, and the conductivity of the conductive connector is greater than that of the electrode.

8. The electrode device according to claim 3, characterized in that, The conductive mesh is embedded near the lower surface of the spray head.

9. The electrode device according to claim 6, characterized in that, It also includes a shielding cover for sealing the reaction chamber of the semiconductor process equipment, the DC power supply being installed on the outside of the shielding cover, and the filter module being installed on the inside of the shielding cover.

10. A semiconductor process apparatus, characterized in that, The device includes a reaction chamber, a radio frequency device, and an electrode device as described in any one of claims 1 to 9, wherein the electrode device is installed in the reaction chamber, and the radio frequency device is used to feed radio frequency to the electrode element of the electrode device. The radio frequency device includes a radio frequency power supply and a matching unit. The radio frequency power supply is connected to the matching unit, and the matching unit is connected to the electrode through a radio frequency connector. The measurement unit is connected to the matching unit.

11. A voltage regulation method, characterized in that, The electrode device according to any one of claims 1 to 9 comprises: Obtain the DC bias voltage; The corrected bias voltage is determined based on the DC bias voltage; The corrected bias voltage is applied to the electrode.

12. The voltage regulation method according to claim 11, characterized in that, After measuring the DC bias voltage, the method further includes: Compare the DC bias voltage with the bias threshold; If the DC bias voltage is greater than the bias threshold, then the step of determining the corrected bias voltage based on the DC bias voltage is performed; If the DC bias voltage is less than the bias threshold, repeat the step of measuring the DC bias voltage.

13. The voltage regulation method according to claim 12, characterized in that, After applying the corrected bias voltage to the electrode, the method further includes: Repeat the steps of measuring the DC bias voltage; Determining the corrected bias voltage based on the DC bias voltage includes: The new corrected bias is the sum of the original corrected bias and the bias increase.

14. The voltage regulation method according to claim 13, characterized in that, The bias voltage increase is the difference between the DC bias voltage and the bias voltage threshold, or half of the difference.

Images