A lower electrode assembly and plasma processing apparatus and method thereof

Abstract

The application discloses a lower electrode assembly, a plasma processing device and a method thereof. The lower electrode assembly comprises: an equipment plate; an electrostatic chuck arranged above the equipment plate, a top surface of the electrostatic chuck being used for carrying a wafer, an electrical element being arranged between the equipment plate and the electrostatic chuck, the electrical element being electrically insulated from the equipment plate and the electrostatic chuck; a direct current power supply used for providing a direct current to the electrical element; and an alternating current power supply used for providing an alternating current to the electrical element. The direct current value provided by the direct current power supply to the electrical element and the alternating current value provided by the alternating current power supply to the electrical element can be adjusted, so as to quickly adjust an influencing factor of a process environment in a cavity. The direct current value provided by the direct current power supply to the electrical element and / or the alternating current value provided by the alternating current power supply to the electrical element can be adjusted, so as to quickly adjust the influencing factor of the process environment in the cavity, effectively shorten a response time of process environment conversion, and help improve the regulation precision of the environment in the cavity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor equipment, in particular to a lower electrode assembly and a plasma processing device and method thereof. BACKGROUND

[0002] In the manufacturing process of semiconductor devices, plasma etching, physical vapor deposition, chemical vapor deposition and other process methods are often used to micro-fabricate semiconductor process pieces or wafer substrates. The step of micro-fabrication manufacturing can include a plasma assisted process, which is generally carried out in a vacuum reaction chamber. The plasma etching process in the plasma assisted process is a key process for processing wafers into a designed pattern.

[0003] With the vigorous development of semiconductor technology and the increasing integration of devices, the size of chips is getting smaller and smaller. Size reduction is one of the driving forces for the development of integrated circuit processing. By reducing the size, cost efficiency and device performance can be improved simultaneously. In order to ensure the quality of the chip, the process requirements for semiconductor are also getting higher and higher. Although semiconductor processing devices have been updated many times and their performance has been greatly improved, there are still many deficiencies in the control of process conditions and the adjustment of process environment. The existing processing method and equipment have been difficult to meet the requirements of wafer surface processing.

[0004] In the wafer processing process, many process environment influencing factors will affect the quality of wafer surface processing, such as the response time of process conversion in the chamber (especially in the initial stage of process), the distribution of temperature field and magnetic field, the flow and distribution of process gas, and the pressure distribution in the chamber, etc. They directly determine the quality of wafer processing production. If the process environment in the reaction area of the reaction chamber is not completely consistent, it is easy to cause the phenomenon of uneven wafer surface processing effect (such as uneven wafer surface processing depth, uneven composition, uneven physical properties), which further reduces the yield of wafer production. However, in practical application, the process environment in the vacuum reaction chamber is often complex, and the adjustment of the chamber environment often affects the whole system, making it difficult to achieve the optimal condition of various factors. Therefore, it is necessary to improve the existing semiconductor processing device to meet the actual process requirements.

[0005] It can be understood that the above statements only provide background technology related to the present application, and do not necessarily constitute prior art. SUMMARY

[0006] The application aims to provide a lower electrode assembly, a plasma processing device and a method thereof, which relates to the technical field of semiconductors, and the lower electrode assembly comprises an electrical element connected with a direct current power supply and an alternating current power supply, the direct current value applied to the electrical element by the direct current power supply and / or the alternating current value applied to the electrical element by the alternating current power supply can be adjusted, the influencing factors of the process environment can be quickly adjusted, and the response time of the process environment conversion is effectively shortened; the lower electrode assembly can realize the regulation and control of the wafer etching state without additional heaters, and helps to improve the regulation and control precision of the cavity environment.

[0007] In order to achieve the above-mentioned purpose, the application is realized by the following technical scheme:

[0008] A lower electrode assembly used in a vacuum reaction cavity, the lower electrode assembly comprises:

[0009] An equipment plate;

[0010] An electrostatic chuck arranged above the equipment plate, the top surface of the electrostatic chuck is used to carry a wafer, and an electrical element is arranged between the equipment plate and the electrostatic chuck, the electrical element is electrically insulated between the equipment plate and the electrostatic chuck;

[0011] A direct current power supply used to provide a direct current to the electrical element;

[0012] An alternating current power supply used to provide an alternating current to the electrical element;

[0013] Wherein, the direct current value applied to the electrical element by the direct current power supply and the alternating current value applied to the electrical element by the alternating current power supply can be adjusted, so as to quickly adjust the influencing factors of the process environment.

[0014] Optionally, the influencing factors of the process environment comprise at least one of temperature, magnetic field strength and magnetic field distribution;

[0015] Wherein, the magnetic field strength and the magnetic field distribution in the vacuum reaction cavity are adjusted by adjusting the direct current value applied to the electrical element by the direct current power supply;

[0016] The temperature in the vacuum reaction cavity is adjusted by adjusting the alternating current value applied to the electrical element by the alternating current power supply.

[0017] Optionally, the lower electrode assembly comprises a plurality of electrical elements.

[0018] Optionally, the plurality of electrical elements are uniformly distributed in a plane parallel to the electrostatic chuck.

[0019] Optionally, the vacuum reaction chamber is provided with an opening which is in communication with the inside and outside of the vacuum reaction chamber, and the distribution density of the electrical components near the opening is greater than or equal to the distribution density of the electrical components far from the opening.

[0020] Optionally, the direct current power supply comprises a plurality of independently adjustable sub-direct current power supplies, each of which is electrically connected to each electrical component to respectively regulate the direct current applied to each electrical component.

[0021] Alternatively, the direct current power supply is electrically connected to a plurality of electrical components to respectively regulate the direct current applied to each electrical component.

[0022] Optionally, the alternating current power supply comprises a plurality of independently adjustable sub-alternating current power supplies, each of which is electrically connected to each electrical component to respectively regulate the alternating current applied to each electrical component.

[0023] Alternatively, the alternating current power supply is electrically connected to a plurality of electrical components to respectively regulate the alternating current applied to each electrical component.

[0024] Optionally, the electrical component is an electromagnetic coil.

[0025] Optionally, the electromagnetic coil has a spiral, radial or annular shape.

[0026] Optionally, a filter is provided between the direct current power supply and the electrical component.

[0027] Optionally, an adhesive layer is provided between the device plate and the electrostatic chuck, and the electrical component is arranged in the adhesive layer.

[0028] Optionally, a plasma processing device comprises:

[0029] a vacuum reaction chamber;

[0030] a lower electrode assembly arranged at the bottom of the vacuum reaction chamber;

[0031] an upper electrode assembly arranged opposite to the lower electrode assembly.

[0032] Optionally, a control method of a lower electrode assembly is applied to the aforementioned lower electrode assembly, and the control method of the lower electrode assembly comprises:

[0033] at the beginning of the processing process, direct current and alternating current are simultaneously applied to the electrical component by the direct current power supply and the alternating current power supply to quickly adjust the influencing factors of the process environment; wherein the output power of the direct current power supply and the alternating current power supply is controlled according to the temperature of the electrostatic chuck.

[0034] Optionally, the step of applying the direct current and the alternating current to the electrical element simultaneously by the direct current power supply and the alternating current power supply specifically comprises:

[0035] The direct current applied to the electrical element by the direct current power supply gradually decreases from an initial direct current value to a preset direct current value, and when the temperature of the electrostatic chuck reaches a preset temperature, the alternating current applied to the electrical element by the alternating current power supply gradually decreases to a preset alternating current value to maintain the temperature of the electrostatic chuck at a target temperature.

[0036] Optionally, the method further comprises:

[0037] When processing a switching process and the process environment needs to be changed, the direct current applied to the electrical element by the direct current power supply is adjusted to adjust the magnetic field strength and magnetic field distribution in the vacuum reaction chamber, and / or the alternating current applied to the electrical element by the alternating current power supply is adjusted to adjust the temperature in the vacuum reaction chamber.

[0038] Optionally, the lower electrode assembly comprises a plurality of electrical elements, and the direct current applied to the plurality of electrical elements by the direct current power supply is adjusted respectively, so that the direct current values of the plurality of electrical elements are the same, partially the same, or different.

[0039] Optionally, the vacuum reaction chamber is provided with an opening that can communicate the inside and outside of the vacuum reaction chamber, the lower electrode assembly comprises a plurality of electrical elements, and the direct current applied to the plurality of electrical elements by the direct current power supply is adjusted respectively, so that the direct current value of the electrical element close to the opening side is greater than or equal to the direct current value of the electrical element far from the opening side.

[0040] Compared with the prior art, the present application has the following advantages:

[0041] In the lower electrode assembly, the plasma processing device and the method of the present application, the lower electrode assembly comprises an electrical element arranged between a device plate and an electrostatic chuck, the electrical element is electrically insulated from the device plate and the electrostatic chuck, the electrical element is connected with a direct current power supply providing a direct current and an alternating current power supply providing an alternating current respectively, and the direct current applied to the electrical element by the direct current power supply and / or the alternating current applied to the electrical element by the alternating current power supply is adjusted, so that the influencing factors of the process environment can be quickly adjusted, and the process conditions can be changed. The lower electrode assembly can effectively shorten the response time of the process environment conversion, and is helpful to improve the regulation and control accuracy of the cavity environment. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 It is a schematic view of a plasma processing device of the present application;

[0043] Figure 2This is a partial circuit diagram of a lower electrode assembly according to the present invention;

[0044] Figure 3 This is a schematic diagram of the local magnetic field of an electrical component according to the present invention;

[0045] Figure 4 This is a schematic diagram of a local magnetic field penetrating an electrostatic chuck in an electrical component according to the present invention;

[0046] Figure 5 This is a schematic diagram of the electrical component distribution according to the present invention;

[0047] Figure 6 This is a schematic diagram of the shape of an electrical component according to the present invention;

[0048] Figure 7 This is a schematic diagram of a short-time process adjustment according to the present invention;

[0049] Figure 8 This is a schematic diagram of a long-term process adjustment according to the present invention. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] It should be noted that, in this document, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Unless otherwise specified, an element defined by the phrase "comprising..." or "including..." does not exclude the presence of additional elements in the process, method, article, or terminal device that includes said element.

[0052] It should be noted that the accompanying drawings are all in a very simplified form and use non-precise ratios, and are only used to facilitate and clearly illustrate the purpose of the embodiments of the present invention.

[0053] like Figure 1As shown, a plasma processing apparatus according to the present invention includes: a vacuum reaction chamber 100, which is at least surrounded by a reaction chamber body 101 and a chamber end cap 102. The reaction chamber body 101 is typically made of a metallic material and includes a chamber sidewall and a chamber bottom wall. A wafer transfer port 103 is provided on the chamber sidewall for transferring a wafer W between the inside and outside of the vacuum reaction chamber 100. The vacuum reaction chamber 100 includes a lower electrode assembly 110, which is disposed at the bottom of the vacuum reaction chamber 100. The lower electrode assembly 110 includes a device plate 111 and an electrostatic chuck 112. The electrostatic chuck 112 is disposed above the device plate 111, and its top surface is used to hold the wafer W. The wafer W to be processed, which is transferred into the vacuum reaction chamber 100, is placed on the top surface. The vacuum reaction chamber 100 also includes an upper electrode assembly 120 disposed opposite to the lower electrode assembly 110. The upper electrode assembly 120 includes a gas spray device 121, which is connected to a gas supply device 122. The process gas in the gas supply device 122 enters the vacuum reaction chamber 100 through the gas spray device 121 so that it is ionized into plasma between the lower electrode assembly 110 and the upper electrode assembly 120 and subjected to plasma treatment.

[0054] In practical applications, the main method for controlling the processing environment of wafer W within the cavity is to adjust the surface temperature of the electrostatic chuck 112. However, this method has some drawbacks. For example, it takes a certain amount of time to bring the temperature of the electrostatic chuck 112 to a stable preset temperature. Although the adjustment time to reach a stable preset temperature can be reduced by improving the temperature control algorithm and heat transfer path, this adjustment time is still relatively long. At the same time, traditional temperature control methods will affect adjacent areas, making it difficult to achieve very precise temperature control. On the other hand, there are also some temperature-insensitive processes in the wafer W processing, and even if the temperature of the electrostatic chuck 112 is adjusted, it is difficult to achieve the required adjustment effect.

[0055] Based on the above, such as Figure 1 and Figure 2As shown, in this invention, the lower electrode assembly 110 further includes an electrical component 113, a DC power supply 114, and an AC power supply 115. The electrical component 113 is disposed between the device plate 111 and the electrostatic chuck 112, and is electrically insulated from both the device plate 111 and the electrostatic chuck 112. The DC power supply 114 provides direct current (DC) to the electrical component 113, and the AC power supply 115 provides alternating current (AC) to the electrical component 113. Furthermore, by adjusting the DC current value applied by the DC power supply 114 to the electrical component 113 and the AC current value applied by the AC power supply 115 to the electrical component 113, the influencing factors of the process environment can be quickly adjusted, thereby changing the internal process environment.

[0056] In this application, the electrical component 113 is connected to both the AC power supply 115 and the DC power supply 114, such as... Figure 2 The diagram shows the power supply principle of the electrical component 113. Connected to both DC power supply 114 and AC power supply 115, the electrical component 113 functions as both a heater and a magnetic coil. It can adjust the temperature of its corresponding reaction area and regulate the magnetic field environment of the reaction area, thereby affecting the processing of wafer W. Specifically, applying AC current to the electrical component 113 via AC power supply 115 heats the electrostatic chuck 112. In this case, the electrical component 113 acts as a heater. Adjusting the value of the AC current applied to the electrical component 113 further regulates the temperature range of the electrostatic chuck 112, thus affecting the etching state of wafer W. On the other hand, applying DC current to the electrical component 113 via DC power supply 114 causes the electrical component 113 to act as a magnetic coil, generating a local magnetic field. For ease of description, as shown... Figure 3 and Figure 4 As shown, an electrical component 113 arranged circumferentially is simplified as an elliptical coil. A gradually contracting local magnetic field environment is formed from above the electrical component 113 to the surface of the electrical component 113 and below it. The direction of the magnetic field is as follows: Figure 3As shown, this local magnetic field can regulate the processing state of wafer W in this region. During processing, the plasma concentration in this region increases, resulting in a stronger processing intensity in the reaction region corresponding to the electrical component 113. Adjusting the magnitude of the DC current applied to the electrical component 113 can further regulate the plasma concentration in the reaction region corresponding to the electrical component 113, thereby affecting the processing of wafer W. Understandably, the DC current applied to the electrical component 113 will inevitably heat this region as well, but at this time, the magnetic field generated by the electrical component 113 has a much greater impact on plasma processing than on temperature.

[0057] In this embodiment, the influencing factors of the process environment include at least one of temperature, magnetic field strength, and magnetic field distribution. The magnetic field strength and magnetic field distribution within the vacuum reaction chamber 100 are adjusted by regulating the DC current applied to the electrical component 113 by the DC power supply 114; the temperature within the vacuum reaction chamber 100 is adjusted by regulating the AC current applied to the electrical component 113 by the AC power supply 115.

[0058] In practical applications, DC or AC current can be applied to electrical component 113 individually or simultaneously as needed to adjust the process environment within the cavity and meet different application requirements. For example, in some temperature-sensitive processes where magnetic field interference is undesirable (e.g., wafer W contains hard or soft magnetic materials), only AC current is applied to electrical component 113, which then primarily functions as a heater for temperature control. In this embodiment, DC and AC currents can also be applied to electrical component 113 simultaneously via DC power supply 114 and AC power supply 115, adjusting the magnitude of the applied DC and AC currents to quickly adjust the process environment within the vacuum reaction chamber 100. The output power of DC power supply 114 and AC power supply 115 is controlled according to the temperature of the electrostatic chuck 112 to quickly reach the preset process environment, shortening the response time for process environment transitions and improving control accuracy. In other words, the ratio of DC and AC currents applied to electrical component 113 is adjusted based on the temperature of the electrostatic chuck 112. For example, at the start of the processing, simultaneously applying DC or AC current to electrical component 113 can quickly bring the cavity processing environment to a preset state, effectively shortening the response time during process switching. The time spent adjusting the cavity environment by regulating the current is significantly shorter than that spent by simply adjusting the temperature, and this method minimizes the impact on adjacent areas, improving the precision of cavity environment control. This control method is particularly suitable for temperature-insensitive processes and processes requiring short-term process switching, achieving rapid process environment transitions through the combined effects of temperature and magnetic fields. Furthermore, this invention eliminates the need for an additional heater to regulate the temperature of the electrostatic chuck 112. Electrical component 113, connected to both DC power supply 114 and AC power supply 115, can not only control the cavity temperature but also adjust the cavity magnetic field, thereby adjusting the processing state of the wafer W surface.

[0059] It is understood that the types of parameters included in the influencing factors of the process environment are not limited to those mentioned above. They may also include other functional parameters affected by the regulation of electrical components 113 via DC power supply 114 and AC power supply 115. This invention does not impose any limitations on this. Furthermore, this invention does not limit the number of electrical components 113. Regardless of the number of electrical components 113 included in the lower electrode assembly 110, the aforementioned adjustment and control effects can be achieved. For example, in one embodiment, the lower electrode assembly 110 includes one electrical component 113, the electromagnetic influence range of which covers the entire electrostatic chuck 112, in order to better regulate the process environment of the reaction zone.

[0060] In this embodiment, an adhesive layer 116 is provided between the device board 111 and the electrostatic chuck 112, and the electrical component 113 is disposed within the adhesive layer 116 to achieve electrical insulation between the electrical component 113 and the electrostatic chuck 112 and the device board 111. The present invention does not limit the thickness of the adhesive layer 116, as long as it can achieve the corresponding functional purpose.

[0061] like Figure 1 and Figure 5 As shown, in this embodiment, the lower electrode assembly 110 includes multiple electrical components 113. Each electrical component 113 is independent / electrically isolated from each other. The DC current and AC current applied to each electrical component 113 can be adjusted separately, meaning that each electrical component 113 affects the process environment of its respective region, thereby enabling individual control of the process environment in different regions. In practical applications, adjustments can be made to each region based on the degree of difference in the processing environment. For example, the magnetic field strength in regions with lower processing rates can be increased (by increasing the DC current applied to the corresponding electrical component 113 in that region), making the originally uneven wafer W surface more uniform. Furthermore, in this embodiment, the multiple electrical components 113 are uniformly distributed in a plane parallel to the electrostatic chuck 112, meaning that the distribution density of electrical components 113 in each region of the plane is equal, achieving symmetrical distribution across the entire range. This allows for the control of the uniformity of the process environment in each region within the cavity, helping to improve the control accuracy of each region. It is easy to understand that, in order to further improve control accuracy, the size of electrical component 113 can be reduced, such as the area occupied by electrical component 113 being less than 1 mm². 2 Preferably, the area occupied by electrical component 113 is 3-16 mm². 2 .

[0062] It should be noted that in actual use, the distribution of each electrical component 113 can be adjusted according to actual needs (control area and accuracy). As mentioned above, the vacuum reaction chamber 100 has openings (such as wafer transfer ports 103) that connect the inside and outside of the vacuum reaction chamber 100, which can easily affect the uniformity of plasma distribution within the chamber. For example, in practical applications, an exhaust port is usually provided on one side biased towards the bottom of the chamber. The vacuum extraction device uses this exhaust port to extract waste products generated during the process to the outside of the vacuum reaction chamber 100. In this process, because the exhaust port is biased towards one side of the chamber, the pumping efficiency is higher on the side closer to the exhaust port. The residence time of the reactive gas at different positions above the wafer W is unequal, resulting in differences in plasma concentration distribution at different positions above the wafer W. This leads to a bias in the wafer W processing rate and easily causes uneven processing of the wafer W. At the same time, the presence of wafer transfer ports 103 on the sidewall of the chamber causes asymmetry in the radio frequency path within the chamber, which in turn leads to asymmetry in plasma distribution. Furthermore, as the processing is repeated, different components are consumed (e.g., focusing rings), resulting in asymmetry in plasma distribution.

[0063] Based on the aforementioned technical problems, in this invention, the plasma concentration within the cavity can be balanced by adjusting the distribution density of electrical components 113 in different regions, and / or by adjusting the DC current applied by the DC power supply 114 to electrical components 113 at different locations, and / or by adjusting the AC current applied by the AC power supply 115 to electrical components 113 at different locations, thereby controlling the temperature in different regions and improving the processing uniformity of wafer W in all directions. For example, in one embodiment, the distribution density of electrical components 113 near the opening is greater than that far from the opening, so that the plasma distribution within the vacuum reaction chamber 100 is more uniform, improving the processing uniformity of wafer W. In another example, during the adjustment process, the DC current applied by the DC power supply 114 to multiple electrical components 113 is adjusted so that the DC current value of the electrical components 113 near the opening is greater than that far from the opening, to balance the plasma distribution density within the cavity and ensure the processing uniformity of wafer W. Therefore, multiple independent electrical components 113 can control the plasma state in different regions of the cavity, reducing the impact of uneven processing caused by factors such as unbalanced equipment structure or component wear. On the other hand, they can also meet the different requirements of plasma concentration or etching rate in different regions in different processes, such as local adjustment of plasma distribution in some processes.

[0064] It is understood that the opening of the aforementioned vacuum reaction chamber 100 is not limited to the wafer transfer port 103 or the exhaust port; it can also be other openings, and the present invention does not limit this. Furthermore, the aforementioned methods of adjusting the distribution density of electrical components 113 at different positions and adjusting the DC current value applied to electrical components 113 at different positions are not limited to overcoming the wafer W processing edge problem that may be caused by the opening; they can also be used to solve other needs (such as the processing edge problem caused by the asymmetrical distribution of various connectors encountered in actual operation), and the present invention does not limit this.

[0065] In this invention, each electrical component 113 is independent of the others, and the DC current and AC current applied to each electrical component 113 can be individually controlled. Each electrical component 113 can be individually connected to a DC power supply 114 and / or an AC power supply 115, or it can be at least partially connected to the same DC power supply 114 and / or AC power supply 115, and then the current is distributed and adjusted through a circuit. This invention does not limit this, as long as individual adjustment of each electrical component 113 can be achieved. Optionally, the DC power supply 114 includes multiple independently adjustable sub-DC power supplies 114, each sub-DC power supply 114 being electrically connected to each electrical component 113 to individually control the DC current value applied to each electrical component 113; and / or, the DC power supply 114 is electrically connected to multiple electrical components 113 to individually control the DC current value applied to each electrical component 113. Alternatively, the AC power supply 115 may include a plurality of independently adjustable sub-AC power supplies 115, each sub-AC power supply 115 being electrically connected to a respective electrical component 113 to regulate the AC current value applied to each electrical component 113; and / or, the AC power supply 115 may be electrically connected to a plurality of electrical components 113 to regulate the AC current value applied to each electrical component 113.

[0066] In this embodiment, the electrical component 113 is an electromagnetic coil. Optionally, the electrostatic chuck 112 is made of ceramic material, and the electromagnetic coil is made of a material with high resistance (e.g., tungsten, stainless steel, etc.). An electromagnetic coil made of a material with high resistance can have both heating and magnetic field generation functions. Specifically, the strength of the heating and magnetic field generation functions can be adjusted by selecting the material and resistance value of the electromagnetic coil, so that the wafer W processing environment can be adjusted by regulating the temperature and magnetic field fields. Figure 6As shown, in this embodiment, the electromagnetic coil is spiral-shaped (mosquito coil type). This electromagnetic coil can generate a local magnetic field, which can cover the corresponding reaction area above the electromagnetic coil, so as to adjust the temperature field and magnetic field of the area, thereby adjusting the processing state of wafer W. It is understood that the shape of the electromagnetic coil is not limited to the spiral shape mentioned above; it can also be other shapes, such as rings. The present invention does not limit this, as long as it can achieve its corresponding function. Furthermore, the electrical component 113 is not limited to an electromagnetic coil; it can also be other components with the same function (e.g., not limited to a circumferential shape, such as a radial shape). The present invention does not limit this.

[0067] Furthermore, such as Figure 2 As shown, in this embodiment, a filter 117 (AC filter) is provided between the DC power supply 114 and the electrical component 113 to minimize the AC component in the power voltage output by the DC power supply 114, retain its DC component, reduce the output voltage ripple coefficient, make the waveform smoother, and prevent the power voltage received by the electrical component 113 from being interfered with by AC, thereby enhancing its control accuracy. At the same time, it can also block the AC current generated by the AC power supply 115 to avoid damaging the DC power supply 114.

[0068] Based on the same inventive concept, the present invention also provides a control method for a lower electrode assembly 110. This control method is applied to the aforementioned lower electrode assembly 110. The control method for the lower electrode assembly 110 includes: at the start of the processing, applying both DC current and AC current to the electrical component 113 simultaneously through the DC power supply 114 and the AC power supply 115 to quickly adjust the influencing factors of the process environment; wherein the output power of the DC power supply 114 and the AC power supply 115 is controlled according to the temperature of the electrostatic chuck 112.

[0069] In this embodiment, applying both DC and AC current to the electrical component 113 simultaneously via the DC power supply 114 and the AC power supply 115 specifically includes: the DC current applied by the DC power supply 114 to the electrical component 113 gradually decreasing from an initial DC current value to a preset DC current value; and when the temperature of the electrostatic chuck 112 reaches a preset temperature, the AC current applied by the AC power supply 115 to the electrical component 113 gradually decreasing to a preset AC current value to maintain the temperature of the electrostatic chuck 112 at the target temperature.

[0070] Furthermore, the control method for the lower electrode assembly 110 also includes: when switching processes and requiring a change in the process environment, adjusting the DC current value applied by the DC power supply 114 to the electrical component 113 to adjust the magnetic field strength and magnetic field distribution within the vacuum reaction chamber 100, and / or adjusting the AC current value applied by the AC power supply 115 to the electrical component 113 to adjust the temperature within the vacuum reaction chamber 100. In practical applications, adjustments can be made as needed. For example, such as... Figure 7 As shown, when switching to a short-duration process, the process may end before the temperature reaches the expected level due to the short process time. Therefore, this application changes the process environment by adjusting the DC current applied to the electrical component 113 by the DC power supply 114. That is, it maintains a constant AC current while adjusting the DC current, thereby achieving rapid adjustment of the wafer W's processing state. This adjustment method reduces the influence of temperature factors, making the adjustment more controllable and precise. It is easily understood that this adjustment method is also applicable to temperature-insensitive processes.

[0071] like Figure 8 As shown, in a certain long-term process, DC power supply 114 and AC power supply 115 are used simultaneously. At the beginning of the process or at the start of a process state transition, DC current and AC current are simultaneously applied to electrical component 113 by DC power supply 114 and AC power supply 115. DC current (magnetic field) is used as the primary regulation method, while waiting for the temperature to rise. Specifically, as the difference between the current temperature and the target temperature decreases, the DC current applied by DC power supply 114 to electrical component 113 is gradually reduced until the DC current value is reduced to a preset DC current value. Simultaneously, when the temperature of electrostatic chuck 112 reaches a preset temperature threshold, the AC current applied by AC power supply 115 to electrical component 113 is reduced until its AC current value is reduced to a preset AC current value, thereby regulating the process environment within the vacuum reaction chamber 100. The percentage relationship between the preset temperature threshold and the target temperature can be adjusted and determined according to actual needs or on-site environmental parameters; this invention does not impose any limitations on it. Preferably, in this embodiment, the initial DC current value applied by DC power supply 114 is equal to the initial AC current value applied by AC power supply 115. Optionally, the preset AC current value is greater than the preset DC current value. Further optionally, the preset DC current value is zero, that is, during the steady-state phase, AC current is applied to the electrical component 113 only through the AC power supply 115 to maintain thermal balance.

[0072] Furthermore, in this embodiment, the lower electrode assembly 110 includes a plurality of electrical components 113, and the control method of the lower electrode assembly 110 further includes: adjusting the DC current value applied by the DC power supply 114 to the plurality of electrical components 113 respectively, so that the DC current values ​​of the plurality of electrical components 113 are the same, partially the same or different.

[0073] Furthermore, when the vacuum reaction chamber 100 has an opening that connects the inside and outside of the vacuum reaction chamber 100, the control method of the lower electrode assembly 110 further includes: adjusting the DC current value applied by the DC power supply 114 to the plurality of electrical components 113 respectively, so that the DC current value of the electrical component 113 near the opening side is greater than or equal to the DC current value of the electrical component 113 far from the opening side.

[0074] In summary, the lower electrode assembly 110 and its plasma processing apparatus and method of the present invention include an electrical component 113 disposed between a device plate 111 and an electrostatic chuck 112. The electrical component 113 is electrically insulated from the device plate 111 and the electrostatic chuck 112. The electrical component 113 is connected to a DC power supply 114 providing DC current and an AC power supply 115 providing AC current. By adjusting the DC current applied by the DC power supply 114 to the electrical component 113 and the AC current applied by the AC power supply 115 to the electrical component 113, the influencing factors of the process environment can be quickly adjusted, thereby changing the process environment. This lower electrode assembly 110 can effectively shorten the response time of process environment transitions and improve the accuracy of cavity environment control.

[0075] Furthermore, the lower electrode assembly 110 includes multiple electrical components 113, each independent of the others. The plasma concentration within the cavity can be balanced by adjusting the distribution density of the electrical components 113 in different regions or by adjusting the DC current applied to the electrical components 113 in different regions, thereby improving the processing uniformity of the wafer W in all directions. Multiple independent electrical components 113 can reduce the impact of processing imbalances caused by factors such as uneven cavity equipment structure or component wear. On the other hand, it allows for independent control of the plasma distribution state in each region, meeting the different plasma concentration requirements of different regions in different processes.

[0076] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A lower electrode assembly for use in a vacuum reaction chamber, characterized in that, Include: Equipment board; An electrostatic chuck is disposed above the equipment board. The top surface of the electrostatic chuck is used to support the wafer. An electrical component is disposed between the equipment board and the electrostatic chuck. The electrical component is electrically insulated from the equipment board and the electrostatic chuck. A DC power supply is used to provide DC current to the electrical components; An AC power source is used to provide alternating current to the electrical components; The electrical component connected to both the DC power supply and the AC power supply functions as both a heater and a magnetic coil. It can adjust the magnitude of the DC current applied by the DC power supply to the electrical component and the magnitude of the AC current applied by the AC power supply to the electrical component to quickly adjust the influencing factors of the process environment, which include at least one of temperature, magnetic field strength, and magnetic field distribution.

2. The lower electrode assembly as described in claim 1, characterized in that, The magnetic field strength and magnetic field distribution within the vacuum reaction chamber can be adjusted by regulating the DC current applied to the electrical components by the DC power supply. The temperature inside the vacuum reaction chamber is adjusted by regulating the value of the alternating current applied to the electrical components by the alternating power supply.

3. The lower electrode assembly as described in claim 1, characterized in that, The lower electrode assembly includes a plurality of the electrical components.

4. The lower electrode assembly as described in claim 3, characterized in that, The electrical components are evenly distributed in a plane parallel to the electrostatic chuck.

5. The lower electrode assembly as described in claim 3, characterized in that, The vacuum reaction chamber has an opening that connects the inside and outside of the vacuum reaction chamber, and the distribution density of electrical components near the opening is greater than or equal to the distribution density away from the opening.

6. The lower electrode assembly as described in claim 3, characterized in that, The DC power supply includes multiple independently adjustable sub-DC power supplies, each of which is electrically connected to a specific electrical component to regulate the DC current applied to that component. Alternatively, the DC power supply may be electrically connected to multiple electrical components to regulate the DC current applied to each electrical component.

7. The lower electrode assembly as described in claim 3, characterized in that, The AC power supply includes multiple independently adjustable sub-AC power supplies, each of which is electrically connected to a specific electrical component to regulate the AC current applied to that component. Alternatively, the AC power supply may be electrically connected to multiple electrical components to regulate the AC current applied to each electrical component.

8. The lower electrode assembly as described in claim 1, characterized in that, The electrical component is an electromagnetic coil.

9. The lower electrode assembly as described in claim 8, characterized in that, The electromagnetic coil is spiral, radial, or ring-shaped.

10. The lower electrode assembly as claimed in claim 1, characterized in that, A filter is provided between the DC power supply and the electrical components.

11. The lower electrode assembly as claimed in claim 1, characterized in that, An adhesive layer is provided between the device board and the electrostatic chuck, and the electrical components are disposed within the adhesive layer.

12. A plasma processing apparatus, characterized in that, Include: Vacuum reaction chamber; The lower electrode assembly as described in any one of claims 1 to 11 is disposed at the bottom of the vacuum reaction chamber; The upper electrode assembly is disposed opposite to the lower electrode assembly.

13. A control method for a lower electrode assembly, characterized in that, Applied to the lower electrode assembly as described in any one of claims 1 to 11, comprising: At the start of the process, DC current and AC current are simultaneously applied to the electrical components through the DC power supply and the AC power supply to quickly adjust the influencing factors of the process environment. The output power of the DC power supply and the AC power supply is controlled according to the temperature of the electrostatic chuck.

14. The control method for the lower electrode assembly as described in claim 13, characterized in that, Applying both DC and AC current to the electrical component simultaneously via the DC power supply and the AC power supply specifically includes: The DC current applied by the DC power supply to the electrical component gradually decreases from an initial DC current value to a preset DC current value; and when the temperature of the electrostatic chuck reaches the preset temperature, the AC current applied by the AC power supply to the electrical component gradually decreases to a preset AC current value to maintain the temperature of the electrostatic chuck at the target temperature.

15. The control method for the lower electrode assembly as described in claim 13, characterized in that, Also includes: When switching processes and needing to change the process environment, the DC current applied by the DC power supply to the electrical components is adjusted to adjust the magnetic field strength and magnetic field distribution in the vacuum reaction chamber, and / or the AC current applied by the AC power supply to the electrical components is adjusted to adjust the temperature in the vacuum reaction chamber.

16. The control method for the lower electrode assembly as described in claim 13, characterized in that, The lower electrode assembly includes multiple electrical components, and the DC current value applied by the DC power supply to the multiple electrical components is adjusted so that the DC current values ​​of the multiple electrical components are the same, partially the same, or different.

17. The control method for the lower electrode assembly as described in claim 13, characterized in that, The vacuum reaction chamber has an opening that connects the inside and outside of the vacuum reaction chamber. The lower electrode assembly includes multiple electrical components. The DC current value applied by the DC power supply to the multiple electrical components is adjusted so that the DC current value of the electrical component closer to the opening is greater than or equal to the DC current value of the electrical component farther from the opening.

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