Plasma equipment for forming fluorinated layer of semiconductor wafer heater and processing method

Abstract

The embodiment of the invention provides plasma equipment for forming a fluorinated layer of a semiconductor wafer heater and a processing method, and the equipment comprises a plasma generation device and a reaction chamber, and also comprises a process gas conveying system which is configured to provide independent and controllable process gas for the reaction chamber, comprising a plasma gas path, a central gas path and an edge gas path, the gas guiding device is arranged between the plasma generating device and the reaction chamber, is of a double-layer coaxial structure and comprises an inner-layer channel connected with the central gas path and an outer-layer channel connected with the edge gas path; and the control system is used for independently controlling process parameters of the plasma gas path, the central gas path and the edge gas path. According to the device, a partitioned independent gas supply and layered flow guide structure is adopted, differentiated accurate supply of reaction gas in different areas of the heater is achieved, a fluorinated layer with highly uniform thickness and property is obtained, and the product performance and consistency are remarkably improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing and surface treatment equipment technology, and in particular to a plasma equipment and processing method for forming a fluoride layer in a semiconductor wafer heater. Background Technology

[0002] In semiconductor manufacturing processes, wafer heaters are critical components, and their surface properties directly affect the uniformity and stability of the process. To improve the heater's corrosion resistance, thermal conductivity, and lifespan, a uniform and dense fluorinated layer is typically formed on its surface. The quality of this fluorinated layer, especially its thickness and the consistency of its chemical composition across different areas of the heater surface, is crucial for ensuring product yield in mass production.

[0003] Currently, the industry lacks dedicated plasma equipment for fluorination treatment of heaters, and traditional general-purpose thin-film deposition equipment is commonly used as a substitute. However, this general-purpose equipment is not designed for the process requirements of special workpieces like heaters, and therefore exposes many inherent defects during application.

[0004] First, general-purpose equipment cannot achieve precise and differentiated supply of reactant gases to different areas of the heater surface. Due to the uneven distribution of plasma within the reaction chamber and the temperature gradient on the workpiece surface, the chemical reaction rates differ between the central and peripheral regions. A single gas supply mode cannot compensate for this, resulting in uneven thickness and properties of the formed fluorinated layer, severely affecting the consistency of product performance. Second, fluorination processes often involve the use of toxic and corrosive gases such as SiH4, WF6, and NF3, requiring extremely high safety standards. However, the gas path design of general-purpose equipment is usually relatively simple, lacking dedicated leak-proof and safety interlock mechanisms for such hazardous gases, posing a high risk of gas leakage and operational safety, and failing to meet the stringent safety standards of semiconductor manufacturing. Furthermore, semiconductor heaters come in various specifications and models, while the workpiece clamping and positioning methods of general-purpose equipment are often fixed, making adjustments difficult and resulting in low equipment utilization, increasing users' equipment investment costs. Simultaneously, existing equipment generally lacks integrated intelligent control and data management systems, leading to large fluctuations in process parameters and difficulty in traceable production data, hindering process optimization and refined quality control.

[0005] Therefore, there is an urgent need in the field for an apparatus for forming fluorinated layers in semiconductor wafer heaters to overcome the above-mentioned problems. Summary of the Invention

[0006] This application provides a plasma equipment and processing method for forming a fluorinated layer in a semiconductor wafer heater. The equipment adopts a zoned independent gas supply and layered flow structure, which enables differentiated and precise supply of reaction gas to the center and edge areas of the heater, thereby obtaining a fluorinated layer with highly uniform thickness and properties, significantly improving product performance and consistency. The equipment adopts multiple safety interlocks and purging designs to reduce the risk of leakage of toxic process gases, meeting the safety requirements of semiconductor manufacturing.

[0007] In a first aspect, a plasma apparatus for forming a fluoride layer on a semiconductor wafer heater is provided. The apparatus includes a plasma generator and a reaction chamber, the reaction chamber being used to house the heater to be processed. The apparatus is characterized by comprising: A process gas delivery system configured to supply independently controllable process gas to the reaction chamber, including a plasma gas path, a central gas path, and an edge gas path; A gas guiding device is disposed between the plasma generator and the reaction chamber. The gas guiding device has a double-layer coaxial structure and includes an inner channel connected to the central gas path and an outer channel connected to the edge gas path. A control system is provided for independently controlling the process parameters of the plasma gas path, the central gas path, and the edge gas path.

[0008] It should be understood that the process gases in the central and peripheral gas paths are used for thin film deposition, while the plasma in the plasma gas path is used to remove peeling on the generated thin film or to carry out fluorination reactions.

[0009] In conjunction with the first aspect, in some implementations of the first aspect, the process gas delivery system includes: A plasma gas path, the plasma gas path including a control pneumatic valve and a mass flow controller; Two independent process gas branches correspond to the central gas path and the edge gas path, respectively; Each of the process gas branches includes a front valve, a mass flow controller, and a rear valve arranged sequentially along the gas flow direction; The plasma gas path, the central gas path, and the edge gas path all include a mixed gas pneumatic valve; The process gas branches of both the central gas path and the edge gas path are connected in parallel to the purging branch.

[0010] It should be understood that by independently controlling the central gas path and the edge gas path, the reactant gas can be supplied to different areas of the heater surface in a differentiated and precise manner. This design compensates for the differences in chemical reaction rates caused by uneven plasma distribution and temperature gradient by adjusting the gas concentration distribution, thereby solving the technical problem of uneven fluorinated layer thickness and properties. Finally, a highly uniform fluorinated layer with consistent performance is obtained on the heater surface, improving product yield and process reliability.

[0011] In conjunction with the first aspect, in some implementations of the first aspect, the inner channel is connected to the central gas path through a gas supply pipe; the outer channel is connected to the edge gas path through a gas supply groove, the gas supply groove is provided with multiple diversion baffles, and a guide port is provided between the multiple diversion baffles; a gas supply hole is provided on the side of the gas supply groove near the outer channel, and the gas supply hole and the guide port are spaced apart.

[0012] It should be understood that by setting multiple spaced-apart baffles in the gas delivery tank, the process gas input from the edge gas path can be effectively blocked and redistributed, breaking its original concentrated flow pattern and forcing the gas to disperse and flow in a meandering manner within the tank. After being guided by the baffles, the gas is transported uniformly to the annular space of the outer channel through staggered guide ports and delivery holes. This design significantly improves the uniformity of the gas distribution along the circumference before entering the reaction zone, thereby fundamentally ensuring the uniformity and stability of the reactant supply during the subsequent fluorination reaction in the heater edge region. It effectively overcomes the problem of edge fluorination layer thickness fluctuation caused by uneven initial gas distribution, and improves the uniformity and consistency of the overall process.

[0013] In conjunction with the first aspect, in certain implementations of the first aspect, the control system is configured to execute at least one of the following interlocking logics: For each of the process gas branches, the opening of the valve downstream is conditional upon the opening of the main gas valve corresponding to that branch. For each of the aforementioned process gas branches, the upstream valve and the purge valve operate mutually exclusively and are prohibited from being opened simultaneously. When the downstream valve of each process gas branch is closed, the control system forcibly closes the upstream valve or purge valve of that branch. When the main gas valve is closed, the control system forcibly closes the valves on all its subordinate process gas branches.

[0014] It should be understood that this application constructs an interlocking logic that provides multiple reliable protective barriers for the safe use of toxic or explosive process gases. By setting preconditions for valve opening, mutual exclusion of critical valve operations, and a global and local linkage shutdown mechanism, the risks of dangerous gas mixing, leakage, and misoperation are eliminated at the source, improving the safety level of the equipment and meeting the requirements of the semiconductor manufacturing industry for process safety and stability.

[0015] In conjunction with the first aspect, in some implementations of the first aspect, the device includes a modular adapter detachably disposed within the reaction chamber, the modular adapter being used to support and position the heater, and the modular adapter having standardized mechanical interfaces and vacuum-sealed interfaces.

[0016] It should be understood that the modular adapter design significantly improves equipment utilization and production line response speed through its detachable structure and standardized interfaces, enabling rapid production changeover while ensuring the accuracy of mechanical positioning and the reliability of vacuum sealing during the changeover process.

[0017] In conjunction with the first aspect, in some implementations of the first aspect, the device further includes a vacuum exhaust system, the exhaust port of the reaction chamber being connected to the vacuum exhaust system via a pipe.

[0018] In conjunction with the first aspect, in some implementations of the first aspect, an angle valve and a butterfly valve are connected in series on the pipeline, the angle valve being used for on / off control of the pipeline, and the butterfly valve being used for regulating the exhaust flow and pressure.

[0019] In conjunction with the first aspect, in some implementations of the first aspect, the control system includes a central electrical control cabinet connected to the equipment and configured to: Perform process control, including formula execution and closed-loop parameter adjustment; Conduct security monitoring, including monitoring interlock status and sensor alarms; End-to-end data traceability includes storing process data locally and uploading it to the cloud, and supporting SPC analysis.

[0020] It should be understood that this control system achieves a deep integration of process execution, safety monitoring, and data management. It ensures precise and stable process control through formulation and closed-loop adjustment to obtain a uniform fluorinated layer; it constructs an active safety defense line through real-time monitoring interlocks and sensors to prevent hazards; and it provides data-driven decision-making for quality traceability and continuous optimization through full-process data traceability and SPC analysis, thereby upgrading the equipment into a digital, intelligent, and reliable manufacturing unit.

[0021] In a second aspect, a method for processing a fluorinated layer in a wafer heater is provided, the method employing the apparatus described in any implementation of the first aspect, the method comprising the following steps: S1: Install the heater to be processed into the reaction chamber; S2: Start the plasma generator; S3: Independently control the process gas in the central gas path and the edge gas path, so that it flows to the central region and the edge region of the heater respectively, and / or cooperate with the plasma output from the plasma gas path to form a fluorinated layer on the surface of the heater. S4: After the reaction is complete, stop the flow of process gas and purge the gas path.

[0022] It should be understood that the fluorinated layer is formed on the surface of the heater in at least one of the following ways: Firstly, the process gas in the plasma gas path generates plasma through a remote plasma generator, diffuses down from above, and forms plasma with the required concentration distribution through the gas guiding device, reacting with the metal on the heater surface to form a fluorinated layer. Secondly, the process gases in the central gas path and the edge gas path are controlled independently to flow to their respective regions. Then, the plasma gas path is controlled to output plasma gas, which works synergistically on the surface of the heater to form a fluorinated layer. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a process gas delivery system provided in an embodiment of this application.

[0024] Figure 2 This is a schematic diagram of a gas guiding device provided in an embodiment of this application. Detailed Implementation

[0025] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” and “this” are intended to also include expressions such as “one or more,” unless the context clearly indicates otherwise. It should also be understood that in the following embodiments of this application, “at least one” and “one or more” refer to one, two, or more than two. The term “and / or” is used to describe the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can indicate: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character “ / ” generally indicates that the preceding and following related objects are in an “or” relationship.

[0026] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0027] In semiconductor manufacturing, a uniform fluorinated layer needs to be formed on the surface of the wafer heater to improve performance. The thickness and consistency of its composition directly affect product yield. Currently, the industry lacks dedicated equipment and generally uses general-purpose plasma equipment as a substitute, which has significant limitations: First, it cannot achieve differentiated and precise supply of reactant gases between the center and edge areas of the heater, making it difficult to compensate for reaction differences caused by plasma distribution and temperature gradients, resulting in poor uniformity of the fluorinated layer; Second, the gases used in the fluorination process are mostly toxic and corrosive media, and the gas path design of general-purpose equipment is simple, lacking targeted leak prevention and safety interlocking mechanisms, posing safety hazards; Third, heater specifications vary, and the fixed clamping method of general-purpose equipment makes it difficult to change models, resulting in low equipment utilization; Fourth, there is a lack of integrated intelligent control and data traceability systems, resulting in insufficient process controllability and traceability.

[0028] This application provides a plasma equipment and processing method for forming a fluorinated layer in a semiconductor wafer heater, which can effectively overcome the above-mentioned problems.

[0029] The technical solutions provided in the embodiments of this application will be described below with reference to the accompanying drawings.

[0030] In some examples, the device includes a plasma generator and a reaction chamber for housing a heater to be processed, characterized in that the device includes: A process gas delivery system configured to supply independently controllable process gas to the reaction chamber, including a plasma gas path, a central gas path, and an edge gas path; A gas guiding device is disposed between the plasma generator and the reaction chamber. The gas guiding device has a double-layer coaxial structure and includes an inner channel 1 connected to the central gas path and an outer channel 2 connected to the edge gas path. A control system is provided for independently controlling the process parameters of the plasma gas path, the central gas path, and the edge gas path.

[0031] Figure 1 This is a schematic diagram of a process gas delivery system provided in an embodiment of this application.

[0032] refer to Figure 1 In some examples, the process gas delivery system includes: A plasma gas path, the plasma gas path including a control pneumatic valve and a mass flow controller; Two independent process gas branches correspond to the central gas path and the edge gas path, respectively; Each of the process gas branches includes a front valve, a mass flow controller, and a rear valve arranged sequentially along the gas flow direction; The plasma gas path, the central gas path, and the edge gas path all include a mixed gas pneumatic valve; The process gas branches of both the central gas path and the edge gas path are connected in parallel to the purging branch.

[0033] In one possible implementation, the device has three independent gas paths, corresponding to the plasma gas path and two process gas branches (one central and one peripheral). The plasma gas path connects to the plasma generator and is used to input the working gas to generate plasma. This plasma gas path includes a pneumatic valve and a mass flow controller (MFC). The two process gas branches connect to the process gas source, each containing a pre-valve, an MFC, and a post-valve connected in series. The central and peripheral gas paths are connected in parallel between the pre-valve (pneumatic valve) and the MFC to a nitrogen purging branch controlled by an independent purging valve. Finally, each of the three independent gas paths has a pneumatic valve controlling the intake of the mixed gas in each path. All valves and the MFC are centrally controlled. During operation, the central, peripheral, and plasma gas paths are independently controlled to coordinate the fluorination reaction. After the process is completed, the system automatically switches to nitrogen purging mode to ensure pipeline safety. This design achieves independent, precise, and safe control of the plasma environment and process gas supply.

[0034] Figure 2 This is a schematic diagram of a gas guiding device provided in an embodiment of this application.

[0035] refer to Figure 2 In some examples, the inner channel 1 is connected to the central gas path through a gas supply pipe 3; the outer channel 2 is connected to the edge gas path through a gas supply groove 4. The gas supply groove 4 is provided with multiple diversion baffles 41, and a guide port 42 is provided between the multiple diversion baffles 41. A gas supply hole 43 is provided on the side of the gas supply groove 4 near the outer channel 2, and the gas supply hole 43 and the guide port 42 are spaced apart.

[0036] In one possible implementation, the gas delivery channel 4 is coaxially disposed outside the outer layer channel 2, and the gas delivery channel 4 is provided with an interface away from the outer layer channel 2 to connect to the gas input from the edge gas path.

[0037] Optionally, the gas guiding device is provided with multiple through holes 21 at its upper part to introduce the plasma flow transported by the plasma gas path into the device. The multiple through holes 21 are designed with a non-uniform distribution, specifically, the number density of through holes 21 in the peripheral area is higher than that in the central area. This distribution method aims to actively compensate for the natural uneven distribution phenomenon that may occur during plasma transmission, where the plasma is strong in the center and weak at the edges. By increasing the plasma injection flux in the edge area, the plasma flow is made to achieve a more uniform spatial distribution before entering the reaction chamber, thereby creating conditions for a uniform fluorination reaction on the entire heater surface.

[0038] In some examples, the control system is configured to perform at least one of the following interlocking logics: For each of the process gas branches, the opening of the valve downstream is conditional upon the opening of the main gas valve corresponding to that branch. For each of the aforementioned process gas branches, the upstream valve and the purge valve operate mutually exclusively and are prohibited from being opened simultaneously. When the downstream valve of each process gas branch is closed, the control system forcibly closes the upstream valve or purge valve of that branch. When the main gas valve is closed, the control system forcibly closes the valves on all its subordinate process gas branches.

[0039] In some examples, the device includes a modular adapter detachably disposed within the reaction chamber for supporting and positioning the heater, and the modular adapter has standardized mechanical and vacuum-sealed interfaces.

[0040] In some examples, the device also includes a vacuum exhaust system, with the exhaust port of the reaction chamber connected to the vacuum exhaust system via a pipe.

[0041] In some examples, an angle valve and a butterfly valve are connected in series on the pipeline, the angle valve being used for on / off control of the pipeline, and the butterfly valve being used for regulating exhaust flow and pressure.

[0042] In some examples, the control system includes a central electrical control cabinet connected to the equipment and configured to: Perform process control, including formula execution and closed-loop parameter adjustment; Conduct security monitoring, including monitoring interlock status and sensor alarms; End-to-end data traceability includes storing process data locally and uploading it to the cloud, and supporting SPC analysis.

[0043] This application embodiment also provides a method for processing a fluorinated layer in a wafer heater, the method employing the equipment described in any of the above examples, the method comprising the following steps: S1: Install the heater to be processed into the reaction chamber; S2: Start the plasma generator; S3: Independently control the process gas in the central gas path and the edge gas path, so that it flows to the central region and the edge region of the heater respectively, and / or cooperate with the plasma output from the plasma gas path to form a fluorinated layer on the surface of the heater. S4: After the reaction is complete, stop the flow of process gas and purge the gas path.

[0044] In one possible implementation, the operator selects the appropriate modular adapter based on the model of the heater to be processed, and quickly installs it into the reaction chamber through its standardized mechanical and vacuum-sealed interface, precisely mounting the heater onto it for positioning. Subsequently, the operator selects the pre-stored corresponding process formula on the control system's interface. This formula fully defines all key parameters, including vacuum level, plasma power, process timing, plasma gas path, and independent flow rates of the central and peripheral process gases. After starting the fully automated process, the control system executes the following steps sequentially: first, it initializes the system, shuts off all gas paths, and initiates vacuum exhaust; then, after the plasma generator is stably started, it sequentially opens the relevant valves according to a strict interlocking logic, entering the core fluorination reaction stage. In this stage, a metal layer is deposited through thermal reaction. Then, the gas supply to the central and peripheral gas paths is stopped, and the plasma gas supply is started. By adjusting the gas type and flow rate, the plasma ionizes upon passing through the remote plasma source (RPS) to form fluorine-containing plasma, ultimately forming a uniform fluorination layer on the heater surface. After the process timing ends, the system automatically closes the process gas valve and immediately triggers the safety interlock logic, initiating a nitrogen purging procedure to thoroughly replace the pipeline and ensure no toxic gas residue remains. Finally, the chamber is repressurized, and the process ends. Throughout the entire process, the control system synchronously completes full-process safety monitoring and data traceability, verifies interlock status in real time, collects all sensor data and event logs, and simultaneously stores the complete process data package locally and uploads it to the cloud, providing a solid data foundation for process optimization and quality traceability.

[0045] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. Any equivalent modifications or variations made by those skilled in the art based on the content disclosed in the present invention should be included within the scope of protection set forth in the claims.

Claims

1. A plasma apparatus for forming a fluoride layer on a semiconductor wafer heater, the apparatus comprising a plasma generator and a reaction chamber, the reaction chamber being used to house the heater to be processed, characterized in that, The device includes: A process gas delivery system configured to supply independently controllable process gas to the reaction chamber, including a plasma gas path, a central gas path, and an edge gas path; A gas guiding device is disposed between the plasma generator and the reaction chamber. The gas guiding device has a double-layer coaxial structure and includes an inner channel (1) connected to the central gas path and an outer channel (2) connected to the edge gas path. A control system is provided for independently controlling the process parameters of the plasma gas path, the central gas path, and the edge gas path.

2. The device according to claim 1, characterized in that, The process gas delivery system includes: A plasma gas path, the plasma gas path including a control pneumatic valve and a mass flow controller; Two independent process gas branches correspond to the central gas path and the edge gas path, respectively; Each of the process gas branches includes a front valve, a mass flow controller, and a rear valve arranged sequentially along the gas flow direction; The plasma gas path, the central gas path, and the edge gas path all include a mixed gas pneumatic valve; The process gas branches of both the central gas path and the edge gas path are connected in parallel to the purging branch.

3. The device according to claim 1, characterized in that, The inner channel (1) is connected to the central gas path through a gas supply pipe (3); the outer channel (2) is connected to the edge gas path through a gas supply groove (4). The gas supply groove (4) is provided with multiple diversion baffles (41), and a guide port (42) is provided between the multiple diversion baffles (41). A gas supply hole (43) is provided on the side of the gas supply groove (4) near the outer channel (2), and the gas supply hole (43) and the guide port (42) are spaced apart.

4. The device according to claim 2, characterized in that, The control system is configured to execute at least one of the following interlocking logics: For each of the process gas branches, the opening of the valve downstream is conditional upon the opening of the main gas valve corresponding to that branch. For each of the aforementioned process gas branches, the upstream valve and the purge valve operate mutually exclusively and are prohibited from being opened simultaneously. When the downstream valve of each process gas branch is closed, the control system forcibly closes the upstream valve or purge valve of that branch. When the main gas valve is closed, the control system forcibly closes the valves on all its subordinate process gas branches.

5. The device according to claim 1, characterized in that, The device includes a modular adapter detachably disposed within the reaction chamber, the modular adapter being used to support and position the heater; the modular adapter has standardized mechanical interfaces and vacuum-sealed interfaces.

6. The device according to claim 1, characterized in that, The device also includes a vacuum exhaust system, and the exhaust port of the reaction chamber is connected to the vacuum exhaust system via a pipe.

7. The device according to claim 6, characterized in that, Angle valves and butterfly valves are connected in series on the pipeline. The angle valves are used to control the on / off state of the pipeline, and the butterfly valves are used to regulate the exhaust flow and pressure.

8. The device according to any one of claims 1 to 7, characterized in that, The control system includes a central electrical control cabinet, which is connected to the equipment and configured to: Perform process control, including formula execution and closed-loop parameter adjustment; Conduct security monitoring, including monitoring interlock status and sensor alarms; End-to-end data traceability includes storing process data locally and uploading it to the cloud, and supporting SPC analysis.

9. A method for processing a fluorinated layer in a wafer heater, using the equipment as described in any one of claims 1 to 8, characterized in that, The method includes the following steps: S1: Install the heater to be processed into the reaction chamber; S2: Start the plasma generator; S3: Independently control the process gas in the central gas path and the edge gas path, so that it flows to the central region and the edge region of the heater respectively, and / or cooperate with the plasma output from the plasma gas path to form a fluorinated layer on the surface of the heater. S4: After the reaction is complete, stop the flow of process gas and purge the gas path.

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