Temperature control method and system for dual-zone substrate heater

Abstract

This application provides a temperature control method and system for a dual-zone substrate heater. The temperature control method includes acquiring a first equivalent temperature and a first target temperature of the inner zone heating element, and a second equivalent temperature and a second target temperature of the outer zone heating element; in response to receiving an operating condition switching command, obtaining a first compensation power based on the target operating condition and the first target temperature, and obtaining a second compensation power based on the target operating condition and the second target temperature; determining a first base power based on the first equivalent temperature and the first target temperature, and determining a second base power based on the second equivalent temperature and the second target temperature; within the same control cycle after receiving the operating condition switching command, obtaining a first target power of the inner zone heating element based on the first base power and the first compensation power, and obtaining a second target power of the outer zone heating element based on the second base power and the second compensation power. The temperature control method of this application can cope with instantaneous disturbances caused by sudden changes in operating conditions and adapt to various operating conditions and temperature changes.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, specifically to a temperature control method and system for a dual-zone substrate heater. Background Technology

[0002] As semiconductor process nodes continue to evolve towards smaller dimensions, the process window for thin film deposition is constantly narrowing, demanding unprecedented precision in process parameter control. Among these components, the dual-zone substrate heater, as a core component supporting the wafer and providing a stable temperature environment for the process, directly determines the uniformity of thin film growth, stress characteristics, and the yield and reliability of the final product through the stability and response speed of its temperature control.

[0003] In actual semiconductor manufacturing, thin-film deposition processes involve multiple distinct stages. The transitions between these stages introduce significant thermal load disturbances to dual-zone substrate heaters. Current temperature control solutions struggle to effectively handle these sudden changes in operating conditions, leading to temperature fluctuations. This results in decreased reliability of the dual-zone substrate heater, reduced semiconductor product yield, and poor process repeatability. Furthermore, these solutions fail to account for the heat loss of the dual-zone substrate heater as operating conditions and temperature change, further exacerbating temperature fluctuations. Summary of the Invention

[0004] In view of this, this application provides a temperature control method and system for a dual-zone substrate heater, which can effectively cope with instantaneous disturbances caused by sudden changes in operating conditions and adapt to various operating conditions and temperature changes, so as to meet the process requirements of a wide temperature range under multiple operating conditions.

[0005] This application provides a temperature control method for a dual-zone substrate heater. The dual-zone substrate heater includes a ceramic substrate, an inner zone heating element, and an outer zone heating element. The inner zone heating element and the outer zone heating element are concentrically arranged and spaced apart within the ceramic substrate. The inner zone heating element heats the inner zone of the ceramic substrate, and the outer zone heating element heats the outer zone of the ceramic substrate. The temperature control method for the dual-zone substrate heater includes: acquiring the actual first converted temperature and a set first target temperature of the inner zone heating element, and the actual second converted temperature and a set second target temperature of the outer zone heating element; in response to receiving a condition switching command indicating a switch to a target operating condition, obtaining a corresponding first compensation power based on a mapping between the target operating condition and the first target temperature, and determining the compensation power based on the target operating condition and the second target temperature. The system maps the corresponding second compensation power; determines the first base power based on the first converted temperature and the first target temperature, and determines the second base power based on the second converted temperature and the second target temperature; within the same control cycle of receiving the operating condition switching command, the system obtains the first target power based on the first base power and the first compensation power, and controls the inner zone heating element to operate at the first target power so that the first converted temperature is adjusted to the first target temperature; and within the same control cycle of receiving the operating condition switching command, the system obtains the second target power based on the second base power and the second compensation power, and controls the outer zone heating element to operate at the second target power so that the second converted temperature is adjusted to the second target temperature.

[0006] In one embodiment, a first mapping relationship exists between various operating conditions of the dual-zone substrate heater, each calibrated temperature point within a preset temperature range, and the compensation power of the inner zone heating element; a second mapping relationship exists between various operating conditions of the dual-zone substrate heater, each calibrated temperature point within a preset temperature range, and the compensation power of the outer zone heating element. Based on this, obtaining the corresponding first compensation power by mapping the target operating condition and the first target temperature, and obtaining the corresponding second compensation power by mapping the target operating condition and the second target temperature, includes: if the first target temperature is a calibrated temperature point, then obtaining the first compensation power by mapping according to the first mapping relationship based on the target operating condition and the first target temperature; if the second target temperature is a calibrated temperature point, then obtaining the second compensation power by mapping according to the second mapping relationship based on the target operating condition and the second target temperature.

[0007] In one embodiment, obtaining the corresponding first compensation power based on the target operating condition and the first target temperature further includes: if the first target temperature is located between two adjacent calibration temperature points, then mapping the compensation power of the two adjacent calibration temperature points according to the target operating condition and the two adjacent calibration temperature points according to the first mapping relationship; calculating a first linear compensation value based on the temperature difference between the two adjacent calibration temperature points and the first target temperature, and the compensation power of the two adjacent calibration temperature points; and calculating the first compensation power based on the first linear compensation value, the two adjacent calibration temperature points, the first target temperature, and a set nonlinear compensation function. And / or, obtaining the corresponding second compensation power based on the target operating condition and the second target temperature further includes: if the second target temperature is located between two adjacent calibration temperature points, then mapping the compensation power of the two adjacent calibration temperature points according to the target operating condition and the two adjacent calibration temperature points according to the second mapping relationship; calculating a second linear compensation value based on the temperature difference between the two adjacent calibration temperature points and the second target temperature, and the compensation power of the two adjacent calibration temperature points; and calculating the second compensation power based on the second linear compensation value, the two adjacent calibration temperature points, the second target temperature, and a set nonlinear compensation function.

[0008] In one embodiment, the temperature control method further includes: if the fluctuation range of the first converted temperature under the same target operating conditions and the same temperature exceeds the set allowable fluctuation range a set number of times, then the compensation power in the first mapping relationship is adjusted according to the set adjustment step size; or, if the fluctuation range of the second converted temperature under the same target operating conditions and the same temperature exceeds the set allowable fluctuation range a set number of times, then the compensation power in the second mapping relationship is adjusted according to the set adjustment step size.

[0009] In one embodiment, the temperature control method further includes: if the process temperature required for the target operating condition indicated by the operating condition switching command is greater than the process temperature required for the current operating condition, then determining the first compensation power and the second compensation power to be positive values. Alternatively, if the process temperature required for the target operating condition indicated by the operating condition switching command is less than the process temperature required for the current operating condition, then determining the first compensation power and the second compensation power to be negative values.

[0010] In one embodiment, the temperature control method further includes: within a set continuous duration after executing the operating condition switching command, controlling the inner zone heating element to continue operating at a first target power and controlling the outer zone heating element to continue operating at a second target power. After the set continuous duration, if the fluctuation range of the first converted temperature is greater than a preset range, then controlling the inner zone heating element to continue operating at the first target power until the fluctuation range of the first converted temperature is less than the preset range. And / or, after the set continuous duration, if the fluctuation range of the second converted temperature is greater than the preset range, then controlling the outer zone heating element to continue operating at the second target power until the fluctuation range of the second converted temperature is less than the preset range. And / or, after the set continuous duration, if the continuous time for which the fluctuation ranges of both the first and second converted temperatures are less than the preset ranges reaches a set time, then controlling the inner zone heating element to operate at a first base power and controlling the outer zone heating element to operate at a second base power.

[0011] In one embodiment, determining a first base power based on a first conversion temperature and a first target temperature, and determining a second base power based on a second conversion temperature and a second target temperature, includes: performing closed-loop adjustment based on the temperature difference between the first conversion temperature and the first target temperature to obtain the first base power; and performing closed-loop adjustment based on the temperature difference between the second conversion temperature and the second target temperature to obtain the second base power.

[0012] In one embodiment, the temperature control method further includes: when no operating condition switching command is received, performing closed-loop adjustment based on the temperature difference between a first calculated temperature and a first target temperature to obtain a first base power, and controlling the inner zone heating element to operate at the first base power; and performing closed-loop adjustment based on the temperature difference between a second calculated temperature and a second target temperature to obtain a second base power, and controlling the outer zone heating element to operate at the second base power.

[0013] In one embodiment, obtaining the actual first converted temperature of the inner heating element and the actual second converted temperature of the outer heating element includes: obtaining the operating electrical parameters of the inner heating element and the operating electrical parameters of the outer heating element; calculating the resistance of the inner heating element based on the operating electrical parameters of the inner heating element, and obtaining the first converted temperature based on the resistance of the inner heating element and the temperature coefficient of resistance of the inner heating element; calculating the resistance of the outer heating element based on the operating electrical parameters of the outer heating element, and obtaining the second converted temperature based on the resistance of the outer heating element and the temperature coefficient of resistance of the outer heating element.

[0014] The second aspect of this application provides a temperature control system for a dual-zone substrate heater. The dual-zone substrate heater includes a ceramic substrate, an inner zone heating element, and an outer zone heating element. The inner zone heating element and the outer zone heating element are concentric and spaced apart within the ceramic substrate. The inner zone heating element is used to heat the inner zone of the dual-zone substrate heater, and the outer zone heating element is used to heat the outer zone of the dual-zone substrate heater. The temperature control system is communicatively connected to the operating condition control system of the dual-zone substrate heater. The temperature control system is used to synchronously receive the operating condition switching command when the operating condition control system issues an operating condition switching command. The temperature control system is used to execute the temperature control method described in the first aspect or any embodiment of the first aspect.

[0015] This application has at least the following advantages: The temperature control method and system for a dual-zone substrate heater provided in this application employs a composite control architecture of independent control of inner and outer zones and feedforward compensation. This architecture enables independent control of the temperature in the center and edge zones of the dual-zone substrate heater. Furthermore, during operating condition switching, targeted power feedforward compensation is simultaneously applied to the inner and outer heating elements, ensuring temperature uniformity across the entire dual-zone substrate heater. Through full-temperature-range, full-operating-condition feedforward compensation power mapping, precise feedforward compensation at any temperature point under any operating condition can be achieved, thereby realizing high-precision, stable temperature control and wafer surface temperature uniformity control across all process scenarios. The coordinated operation of independent closed-loop control and feedforward compensation, where the independent closed-loop control eliminates steady-state errors and random disturbances, and the feedforward compensation offsets instantaneous heat load changes caused by operating condition switching, prevents temperature drops, overshoot, or oscillations, ensuring temperature stability.

[0016] Therefore, the temperature control method and system provided in this application can effectively cope with the instantaneous disturbances caused by sudden changes in operating conditions and adapt to various operating conditions and temperature changes. It avoids a series of problems caused by sudden temperature changes, temperature regulation lag, large temperature fluctuations, and the inability of feedforward compensation to adapt to the heat loss of the dual-zone substrate heater as the operating conditions and temperature change due to the switching of operating conditions. It can meet the multi-condition wide temperature range process requirements of semiconductor thin film deposition process. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a thin film deposition apparatus provided in an embodiment of this application.

[0018] Figure 2 This is a connection diagram of the temperature control system, operating condition control system, and dual-zone substrate heater provided in the embodiments of this application.

[0019] Figure 3 This is a flowchart of a temperature control method provided in an embodiment of this application.

[0020] Figure 4This is a control loop diagram of the temperature control method provided in the embodiments of this application.

[0021] Figure 5 This is another flowchart of the temperature control method provided in the embodiments of this application.

[0022] Figure 6 This is a schematic diagram of a temperature control method provided in an embodiment of this application.

[0023] Figure 7 This is another flowchart of the temperature control method provided in the embodiments of this application.

[0024] Figure 8 This is a simulation waveform diagram of a dual-zone substrate heater using a traditional temperature control scheme.

[0025] Figure 9 This is a simulation waveform diagram of a dual-zone substrate heater using the temperature control method provided in the embodiments of this application.

[0026] Explanation of main component symbols Dual-zone substrate heater-10, ceramic substrate-11, support shaft-12, inner zone heating element-111. Outer zone heating element - 112, inner zone - 113, outer zone - 114, process chamber - 20, other process actuators - 30 Temperature control system - 40, power supply circuit - 41, internal zone power supply - 411, external zone power supply - 412, control circuit - 42. Inner zone controller-421, outer zone controller-422, operating condition control system-50, thin film deposition equipment 100, Wafer-200. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application. Unless otherwise specified, the different embodiments and features described below can be combined with each other.

[0028] like Figure 1 As shown, the thin film deposition equipment 100 is a semiconductor process equipment used to perform thin film deposition processes on the wafer 200. Thin film deposition processes may include chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), etc.

[0029] Thin film deposition equipment 100 includes a process chamber 20, a dual-zone substrate heater 10 (also known as a heating plate), and other process execution mechanisms 30 ( Figure 1 (Simplified diagram), temperature control system 40 and operating condition control system 50.

[0030] A dual-zone substrate heater 10 is used to support and heat the wafer 200, and a temperature control system 40 is used to control the operation of the dual-zone substrate heater 10. The dual-zone substrate heater 10 includes a ceramic substrate 11, which is supported by a support shaft 12. The ceramic substrate 11 is housed within a process chamber 20, and a portion of the support shaft 12 extends outside the process chamber 20. The ceramic substrate 11 is made of a ceramic material with high thermal conductivity and a low coefficient of thermal expansion, such as aluminum nitride (AlN) ceramic. The ceramic substrate 11 has an inner heating element 111 and an outer heating element 112 inside. The inner heating element 111 and the outer heating element 112 are concentric and spaced apart. The inner heating element 111 is located near the center of the ceramic substrate 11, and the outer heating element 112 is located on the outer periphery of the inner heating element 111, near the edge of the ceramic substrate 11.

[0031] The ceramic substrate 11 can be divided into an inner region 113 and an outer region 114. The area enclosed by the inner heating element 111 (including the area within the inner heating element 111 and the arrangement range of the inner heating element 111 itself) is the inner region 113. The remaining area of ​​the ceramic substrate 11 outside the inner region 113, that is, the area where the outer heating element 112 is located, is the outer region 114. The inner heating element 111 is used to heat the inner region 113 of the ceramic substrate 11, and the outer heating element 112 is used to heat the outer region 114 of the ceramic substrate 11, thereby heating the wafer 200 on the ceramic substrate 11 to promote the deposition process and form a thin film on the wafer 200.

[0032] Other process actuators 30 are used to apply various process conditions to the wafer 200. The process condition control system 50 is used to control the operation of the other process actuators 30. Other process actuators 30 include, for example, a vacuum system, pressure regulating valve, gas path system, and spray head. Process conditions may include, for example, chamber pressure, total process gas flow rate, gas type, wafer placement status, and wafer process stage. The temperature control system 40 and the process condition control system 50 can also communicate with remote devices (such as mobile phones, computers, and host computers) and be controlled by the remote devices. As semiconductor process nodes continue to evolve towards 14nm, 7nm, 5nm, and even 3nm, the process window for thin film deposition is constantly narrowing, and the precision requirements for process parameter control have reached unprecedented levels. The dual-zone substrate heater 10 is a core component that supports the wafer 200 and provides a stable temperature environment for the process. The stability and response speed of the temperature control of the dual-zone substrate heater 10 directly determine the uniformity of thin film growth, stress characteristics, and the yield and reliability of the final product.

[0033] In actual semiconductor manufacturing, thin film deposition involves several distinct stages: from the initial wafer preheating stage, to the deposition stage with process gas introduction, and then to the chamber purging and wafer cooling / unloading stages after deposition. The chamber gas pressure ranges from 0 Torr to 1000 Torr across multiple orders of magnitude, and the total process gas flow rate ranges from 10 sccm to 1000 sccm across more than two orders of magnitude. These transitions between operating conditions introduce significant thermal load disturbances to the dual-zone substrate heater 10, placing extremely high demands on its temperature control immunity.

[0034] Current temperature control solutions typically involve placing temperature sensors (e.g., thermocouples TC) at the bottom center and edge of the ceramic substrate 11. The temperature sensors directly collect the actual temperature of the ceramic substrate 11. Based on the actual temperature and the preset target temperature, the controller obtains the target power through a PID control algorithm or model prediction algorithm, and adjusts the actual power of the inner heating element 111 and the outer heating element 112 according to the target power to achieve closed-loop temperature regulation.

[0035] However, after investigation, the applicant found that: (1) Current temperature control schemes are essentially reactive adjustment mechanisms, with inherent disturbance propagation lag and control lag. Specifically, the temperature sensor is located at the bottom of the ceramic substrate, and there is thermal resistance between it and the heating element and the ceramic substrate. This means that when the operating conditions change and the heat load changes, it takes a certain amount of time for heat to be transferred to the temperature sensor. For example, for aluminum nitride ceramic substrates with a thickness of 10mm to 20mm, the heat transfer lag time is usually between 0.5s and 2s. The control algorithm also needs a certain amount of time to calculate the power and adjust the power. The overall control lag time is usually more than 100ms.

[0036] The combined effects of disturbance propagation lag and control lag can lead to temperature fluctuations when operating conditions change abruptly. Furthermore, the heat dissipation characteristics of heating elements vary significantly with temperature; for example, the heat loss at 50°C can differ by more than 10 times from that at 500°C. In addition, the heat load varies greatly between different process conditions; for instance, the convective heat loss differs significantly between chambers with 0 Torr and 1000 Torr of gas. This results in more pronounced disturbance propagation lag and control lag under higher temperature or process conditions, leading to greater temperature fluctuations. Taking 100°C temperature control as an example, the heating element's own temperature will initially drop by 2°C to 3°C (and even more at higher temperatures), while the temperature sensor will detect a drop of 5°C to 6°C. It takes tens of seconds (approximately 30 seconds) to adjust back to the target temperature, making it impossible to completely avoid sudden temperature changes and failing to meet the process requirements of advanced semiconductor manufacturing.

[0037] (2) Ceramics are typical brittle materials with a certain coefficient of thermal expansion. When the temperature fluctuates, the ceramic substrate will frequently expand thermally, thus generating thermal stress. Frequent thermal stress impacts can cause microcracks inside the ceramic substrate, and after long-term use, failure problems such as ceramic substrate breakage and heating element open circuit will occur, shortening the service life of the dual-zone substrate heater and being detrimental to production costs and efficiency.

[0038] Temperature fluctuations also affect thin-film processes. For example, in the copper interconnect PVD deposition process of 14nm semiconductor manufacturing, a temperature fluctuation of 1°C can cause a change of about 2% in the thin film growth rate, and a temperature fluctuation of 5°C can cause a film thickness deviation of more than 8% between the wafer edge and center, far exceeding the ±3% process requirement, directly leading to a decrease in product yield. Moreover, the randomness of temperature fluctuations can lead to poor consistency of process results between different batches of wafers, longer process debugging cycles, and reduced production efficiency.

[0039] In other words, current temperature control solutions are ill-equipped to handle sudden, transient disturbances in operating conditions, leading to temperature fluctuations. This results in decreased reliability of dual-zone substrate heaters, reduced semiconductor product yield, and poor process repeatability. Furthermore, the solutions suffer from poor adaptability to operating conditions and temperature ranges, failing to account for the heat loss of dual-zone substrate heaters as operating conditions and temperature change, further exacerbating temperature fluctuations.

[0040] Therefore, this application provides a temperature control system 40 and a temperature control method for a dual-zone substrate heater, which can be applied to the above-mentioned thin film deposition equipment 100 and used to control the temperature of the dual-zone substrate heater 10. It can also effectively cope with instantaneous disturbances caused by sudden changes in operating conditions and adapt to various operating conditions and temperature changes.

[0041] Therefore, the temperature control system and temperature control method of the present application can meet the process requirements of a wide temperature range under multiple operating conditions. For example, they can be applied to semiconductor process scenarios that require high-precision temperature control, such as PVD, CVD, ALD, and plasma etching of semiconductor processes at 14nm and below, and can achieve a wide temperature range of 50℃ to 500℃ as well as various cavity pressure and flow rate conditions.

[0042] The technical solution of this application is described below.

[0043] Please refer to the following: Figure 1 and Figure 2 The temperature control system 40 of the dual-zone substrate heater 10 provided in this application embodiment includes a power supply circuit 41 and a control circuit 42. The power supply circuit 41 is electrically connected to the control circuit 42, the inner zone heating element 111 and the outer zone heating element 112 of the dual-zone substrate heater 10, and the control circuit 42 is electrically connected to the inner zone heating element 111 and the outer zone heating element 112.

[0044] The structure of the dual-zone substrate heater 10 and the application scenarios of the temperature control system 40 can be referenced. Figure 1 The relevant content will not be repeated here. In this embodiment, both the inner heating element 111 and the outer heating element 112 are resistance heating elements, such as heating wires, heating tubes, or graphite heating elements. Resistance heating elements have a temperature coefficient of resistance, which characterizes the relationship between the resistance and temperature of the heating element. The temperature coefficient of resistance can be a positive coefficient (i.e., the resistance increases as the temperature rises) or a negative coefficient (i.e., the resistance decreases as the temperature rises), depending on the material of the heating element, and no limitation is made here.

[0045] The power supply circuit 41 provides power to the inner zone heating element 111 and the outer zone heating element 112 through different independent power supply lines. The control circuit 42 is used to detect the operating parameters of the inner zone heating element 111 and the outer zone heating element 112, and to control the two power outputs of the power supply circuit 41. After being powered on, the inner zone heating element 111 can heat the inner zone 113, and the outer zone heating element 112 can heat the outer zone 114 after being powered on.

[0046] In a specific implementation, such as Figure 2As shown, the power supply circuit 41 may include an inner zone power supply and an outer zone power supply. The inner zone power supply 411 and the outer zone power supply 412 can be selected from appropriate general-purpose power supplies according to actual conditions, offering high power adjustment accuracy and fast response (e.g., response time less than 10ms). The outer zone heating element 112 and the inner zone heating element 111 can be electrically connected to their respective power supplies via conductive electrodes passing through the support shaft 12. The control circuit 42 may include an inner zone controller 421 and an outer zone controller 422. The inner zone controller 421 is dedicated to controlling the temperature of the inner zone heating element 111, and the outer zone controller 422 is dedicated to controlling the temperature of the outer zone heating element 112. The inner zone controller 421 and the outer zone controller 422 can be selected from appropriate general-purpose controllers (such as microcontrollers) according to actual conditions. Based on this design, the outer zone heating element 112 and the inner zone heating element 111 each have independent controllers and power supplies, which can well support the independent power supply and independent control of the dual-zone substrate heater 10 in terms of hardware topology.

[0047] The control circuit 42 is communicatively connected to the operating condition control system 50 of the dual-zone substrate heater 10. The communication connection method can be wired communication (such as Modbus bus communication, CAN bus communication, RS485 bus communication, etc.) or wireless communication (such as WIFI, Bluetooth, ZigBee, mobile communication, etc.).

[0048] Therefore, when the operating condition control system 50 issues commands (such as operating condition switching commands) to other process actuators 30, the control circuit 42 can synchronously receive the commands. Based on this, the operating condition control system 50 and the temperature control system 40 can work synchronously, which is beneficial to the adaptability of process conditions and temperature control.

[0049] In this embodiment, the control circuit 42 of the temperature control system 40 can also be used to execute the temperature control method for the dual-zone substrate heater provided in this embodiment.

[0050] Next, the temperature control method provided in the embodiments of this application will be described.

[0051] Please see Figure 3 and Figure 4 The temperature control method provided in this application includes: Step S11: Obtain the actual first converted temperature and the set first target temperature of the inner zone heating element, and the actual second converted temperature and the set second target temperature of the outer zone heating element.

[0052] Understandably, both the inner and outer heating elements possess temperature coefficient of resistance characteristics. Therefore, the temperature T of the inner and outer heating elements has a certain relationship with their own resistance R, for example, T = T0 + (R / R). o -1)×PPM. Where, Ro PPM is the resistance of the inner heating element (or outer heating element) at 0℃, and PPM is the temperature coefficient of the inner heating element (or outer heating element).

[0053] Therefore, the process of obtaining the actual first converted temperature of the inner zone heating element and the actual second converted temperature of the outer zone heating element may include: Obtain the operating electrical parameters of the inner heating element and the outer heating element. The operating electrical parameters can be voltage V and current I, where V / I = R.

[0054] Then, the resistance of the inner heating element is calculated based on its working electrical parameters, and the first conversion temperature is obtained based on the resistance and the temperature coefficient of resistance of the inner heating element.

[0055] Similarly, the resistance of the outer heating element is calculated based on its working electrical parameters, and the second conversion temperature is obtained based on the resistance and temperature coefficient of the outer heating element.

[0056] The operating electrical parameters of the inner and outer heating elements can be obtained by sampling with a high-precision sampling resistor. The sampling accuracy of the resistor can reach, for example, 0.01 ohms, resulting in a resistance measurement accuracy better than ±0.01Ω and a temperature conversion accuracy better than ±0.1℃. Therefore, the first converted temperature can accurately represent the heating temperature of the inner heating element, or simply the heating temperature of the inner zone. Similarly, the second converted temperature can accurately represent the heating temperature of the outer heating element, or simply the heating temperature of the outer zone.

[0057] Step S12: In response to receiving a condition switching command for indicating switching to the target condition, obtain the corresponding first compensation power according to the mapping between the target condition and the first target temperature, and obtain the corresponding second compensation power according to the mapping between the target condition and the second target temperature.

[0058] In other words, upon receiving a condition switching command from the process host, power feedforward compensation control is immediately initiated. These condition switching commands include, for example, wafer placement commands, pressure adjustment commands, and gas flow adjustment commands. The target condition indicated by the wafer placement command can be the condition after wafer placement; the target condition indicated by the pressure adjustment command can be the condition after pressure adjustment; and the target condition indicated by the gas flow adjustment command can be the condition after gas flow adjustment.

[0059] like Figure 1As shown, since the operating condition control system and the temperature control system communicate directly, the operating condition control system simultaneously sends the operating condition switching signal to the temperature control system when issuing the operating condition switching command. Compared to the traditional approach of responding only after detecting a temperature change, the temperature control system of this embodiment can respond synchronously to the operating condition switching action without waiting for a temperature change to be detected. This effectively avoids control lag, thereby preventing temperature overshoot and oscillation caused by control lag.

[0060] In this embodiment, a first mapping relationship exists between the various operating conditions of the dual-zone substrate heater, each calibrated temperature point within a preset temperature range, and the compensation power of the inner heating element. A second mapping relationship exists between the various operating conditions of the dual-zone substrate heater, each calibrated temperature point within a preset temperature range, and the compensation power of the outer heating element. Therefore, the first and second mapping relationships cover the entire operating condition and temperature range of the dual-zone substrate heater. Using the first mapping relationship, the first compensation power corresponding to the target operating condition and the first target temperature can be mapped, and using the second mapping relationship, the second compensation power corresponding to the target operating condition and the second target temperature can be mapped.

[0061] The various operating conditions of the dual-zone substrate heater can include various commonly used process conditions for dual-zone substrate heaters. For example, Condition 1 is: preheating state, chamber pressure 0 Torr, gas flow rate 0 sccm. Condition 2 is: deposition state 1, chamber pressure 0 Torr, gas flow rate 200 sccm. Condition 3 is: deposition state 2, chamber pressure 10 Torr, gas flow rate 0 sccm. Condition N is: purging state, chamber pressure 100 Torr, gas flow rate 1000 sccm. It should be understood that the number of operating conditions can be expanded according to actual process requirements and is not limited here.

[0062] The preset temperature range can be set according to actual conditions. The preset temperature range can be divided into multiple calibration temperature points according to temperature calibration intervals. The temperature intervals are set according to accuracy requirements, such as 25℃, 50℃, or other temperature values. For example, assuming the preset temperature range is 50℃~500℃, dividing it into fixed 50℃ intervals will yield calibration temperature points of: 50℃, 100℃, 150℃, 200℃, 250℃, 300℃, 450℃, and 500℃.

[0063] Both the first and second mapping relationships can be pre-stored in the control circuit of the temperature control system in the form of charts, functions, models, etc. For example, as shown in Table 1, the first mapping relationship adopts a two-dimensional matrix table, with the row coordinates being the calibration temperature points in the range of 50℃ to 500℃, and the column coordinates being all commonly used process conditions. Each matrix element (i.e., cell) stores the calibration temperature point in its row and the compensation power corresponding to the condition in its column.

[0064] Table 1 In some embodiments, the first mapping relationship and the second mapping relationship can be established through the following calibration test process: First, the dual-zone substrate heater is heated to the calibrated temperature point, and the temperature is stabilized through closed-loop control (e.g., the temperature fluctuation range is less than ±0.1℃ for more than 1 minute). After the temperature stabilizes, a condition switching operation is performed, and the temperature control system records the temperature changes synchronously.

[0065] After the temperature stabilizes again, record the peak temperature drop ΔT1 of the inner heating element and the peak temperature drop ΔT2 of the outer heating element. Record the time t1 from the temperature drop of the inner heating element to its recovery to the temperature calibration point, and the corresponding error e1(t) between the actual temperature and the temperature calibration point. Record the time t2 from the temperature drop of the outer heating element to its recovery to the temperature calibration point, and the corresponding error e2(t) between the actual temperature and the temperature calibration point.

[0066] Then, calculate and record the initial compensation power under the switching condition: Pfeed1=K1×ΔT1×Kp1+ ×Ki1, Pfeed2=K2×ΔT2×Kp2+ ×Ki2. Where Kp1 and Kp2 are proportional coefficients. Ki1 and Ki2 are integral coefficients. K1 and K2 are compensation coefficients, which can be adjusted empirically to avoid overshoot fluctuations caused by excessive compensation. Then, feedforward compensation is performed using the initial compensation power.

[0067] Repeat the operating condition switching operation, and fine-tune Pfeed1 and Pfeed2 according to the temperature fluctuation of the inner and outer heating elements until the temperature fluctuation of the inner and outer heating elements is less than the set fluctuation range (e.g., ±0.5℃). Record the final compensation power Pfeed1 and Pfeed2 as the compensation power in the first and second mapping relationships.

[0068] Following the above process, the compensation power calibration for all operating conditions at that temperature point is completed sequentially.

[0069] Similarly, complete the compensation power calibration for all operating conditions at each other calibration temperature point.

[0070] Finally, a first mapping relationship and a second mapping relationship are established based on each calibration temperature point and the compensation power under each operating condition.

[0071] In some embodiments, the process of mapping the target operating condition and the first target temperature to obtain the corresponding first compensation power may include: Step A: Determine if the first target temperature is the calibration temperature point. If yes, proceed to Step B; otherwise, proceed to Steps C-E.

[0072] Step B: If the first target temperature is the calibration temperature point, then the first compensation power is obtained by mapping according to the first mapping relationship based on the target operating conditions and the first target temperature.

[0073] For example, you can directly look up Table 1 above based on the target operating condition and the first target temperature to find the compensation power corresponding to the target operating condition and the first target temperature as the first compensation power.

[0074] Step C: If the first target temperature is located between two adjacent calibration temperature points, then according to the target operating condition and the two adjacent calibration temperature points, the compensation power at the two adjacent calibration temperature points is obtained by mapping according to the first mapping relationship.

[0075] Step D: Calculate the first linear compensation value based on the temperature difference between two adjacent calibration temperature points and the first target temperature, and the compensation power of the two adjacent calibration temperature points.

[0076] The first linear compensation value can be calculated using an adaptive interpolation algorithm. The expression for the adaptive interpolation algorithm can be, for example, as follows: (1).

[0077] In the formula, , These are the interpolation weights.

[0078] For example, suppose the first target temperature Ttarget1 is 320℃, and its two adjacent calibration temperature points are: Tlow=300℃, Thigh=350℃, Tlow <Ttarget1<Thigh。

[0079] By referring to Table 1 above, we can obtain the compensation power Plow=20W corresponding to the target operating condition and Tlow, and the compensation power Phigh=100W corresponding to the target operating condition and Thigh.

[0080] Therefore, the temperature difference Thigh-Ttarget1=30℃, Ttarget1-Tlow=20℃, and the power difference of the compensation power between two adjacent calibration temperature points Phigh-Plow=80W. Thus, the first linear compensation value Plfeed1=(20 / 50)×80=32W can be calculated using the adaptive difference algorithm.

[0081] Step E: Calculate the first compensation power based on the first linear compensation value, two adjacent calibration temperature points, the first target temperature, and the set nonlinear compensation function.

[0082] The nonlinear compensation function is used to indicate the nonlinear relationship between the compensation power and the linear compensation value, two adjacent calibration temperature points, and the target temperature. The expression of the nonlinear compensation function can be designed according to the actual situation and is not limited here.

[0083] In one specific implementation, the nonlinear compensation function is a constant 'a' in the low-temperature range (e.g., 300℃~500℃), where 'a' is, for example, close to or equal to 1; the nonlinear compensation function is... .

[0084] The formula for calculating the first compensation power is as follows: (2).

[0085] In the formula, The nonlinear compensation coefficients can be obtained through calibration tests, as shown in the example. It can be 0.002~0.004. Target is the target temperature, for example, the first target temperature in step E, and the second target temperature in step J below. Tavg is the average temperature of two adjacent calibration temperature points, Tavg=(Thigh+Tlow) / 2.

[0086] Similarly, the corresponding second compensation power is obtained by mapping the target operating condition and the second target temperature, including: Step F: Determine if the second target temperature is the calibration temperature point. If yes, proceed to step G; otherwise, proceed to steps H-J.

[0087] Step G: If the second target temperature is the calibration temperature point, then the second compensation power is obtained by mapping according to the second mapping relationship based on the target operating conditions and the second target temperature.

[0088] Step H: If the second target temperature is located between two adjacent calibration temperature points, then according to the target operating condition and the two adjacent calibration temperature points, the compensation power at the two adjacent calibration temperature points is obtained by mapping according to the second mapping relationship.

[0089] Step 1: Calculate the second linear compensation value based on the temperature difference between two adjacent calibration temperature points and the second target temperature, and the compensation power of the two adjacent calibration temperature points.

[0090] Step J: Calculate the second compensation power based on the second linear compensation value, two adjacent calibration temperature points, the second target temperature, and the set nonlinear compensation function.

[0091] It should be understood that steps F to J can be referred to as steps A to D above, and will not be repeated here.

[0092] Understandably, since the compensation power at the calibration temperature point is obtained through calibration testing and has undergone error correction, it possesses accuracy and consistency. Therefore, when the first target temperature (or second target temperature) is the calibration temperature point, the compensation power at the calibration temperature point can be directly used as the first compensation power (or second compensation power). However, when the first target temperature (or second target temperature) is a non-calibration temperature point, considering that the heat loss of the dual-zone substrate heater at high temperatures includes three forms: heat conduction, heat convection, and heat radiation, among which heat radiation loss is proportional to the fourth power of the thermodynamic temperature, and the overall heat loss increases non-linearly with increasing temperature, the simple linear interpolation result is not suitable for the heat loss characteristics of the dual-zone substrate heater and cannot be directly used as the first compensation power (or second compensation power). Therefore, the embodiments of this application correct the linear interpolation result through non-linear compensation to obtain the first compensation power (or second compensation power) that is compatible with the heat loss characteristics of the dual-zone substrate heater.

[0093] The first compensation power can be used to feedforward compensate the actual power of the inner zone heating element, and the second compensation power can be used to feedforward compensate the actual power of the outer zone heating element. Since the embodiments of this application can determine an accurate and appropriate first compensation power for different first target temperatures and an accurate and appropriate second compensation power for different second target temperatures, precise feedforward compensation can be achieved. This can eliminate the disturbance caused by the switching of operating conditions in advance, suppress temperature oscillations, and help ensure control stability and process consistency under all operating conditions.

[0094] Step S13: Determine the first base power based on the first conversion temperature and the first target temperature, and determine the second base power based on the second conversion temperature and the second target temperature.

[0095] Specifically, a first base power can be obtained by performing closed-loop adjustment based on the temperature difference between the first converted temperature and the first target temperature, and a second base power can be obtained by performing closed-loop adjustment based on the temperature difference between the second converted temperature and the second target temperature.

[0096] The first basic power can be understood as the initial target power of the inner zone heating element, and the second basic power can be understood as the initial target power of the outer zone heating element.

[0097] Closed-loop control includes, but is not limited to, PID (Proportional Integral Derivative) control and PI (Proportional Integral) control.

[0098] Taking PI control as an example, the first base power Pbase1 = Kp1 × e1 + Ki1 × ∫(e1)dt, and the second base power Pbase2 = Kp2 × e2 + Ki2 × ∫(e2)dt. Here, Kp1 and Kp2 are proportional coefficients, and Ki1 and Ki2 are integral coefficients. Different PI parameters (i.e., proportional and integral coefficients) can be used for different temperature ranges and different heating elements to improve control performance. e1 is the temperature difference between the first calculated temperature and the first target temperature, and e2 is the temperature difference between the second calculated temperature and the second target temperature. t is time.

[0099] Step S14: Within the same control cycle of receiving the operating condition switching command, obtain the first target power based on the first base power and the first compensation power, and control the inner zone heating element to operate at the first target power so that the first converted temperature is adjusted to the first target temperature; and obtain the second target power based on the second base power and the second compensation power, and control the outer zone heating element to operate at the second target power so that the second converted temperature is adjusted to the second target temperature.

[0100] In step S14, the first base power and the first compensation power can be superimposed, that is, the first base power is fed forward with the first compensation power to obtain the first target power. The first target power is the final target power of the inner zone heating element. Similarly, the second base power and the second compensation power can be superimposed, that is, the first base power is fed forward with the second compensation power to obtain the second target power. The second target power is the final target power of the outer zone heating element.

[0101] During the power compensation process described above, the first base power can be gradually adjusted to the first target power according to the first set slope within a set transition time, and the second base power can be gradually adjusted to the second target power according to the second set slope within a set transition time.

[0102] In other words, by applying feedforward power in a ramp transition manner, the first target power and the second target power are gradually increased at a constant speed, thereby avoiding sudden power changes and thus avoiding current surges and temperature fluctuations.

[0103] The first set slope, the second set slope, and the set transition time can all be set according to the actual situation, and are not limited here. For example, the set transition time can be set to 1s to 5s.

[0104] like Figure 5 As shown, in some embodiments, the temperature control method may further include: Step S31: Analyze the operating condition switching command.

[0105] By analyzing the operating condition switching command, we can determine the direction of the process temperature change corresponding to the target operating condition. For example, assuming the current operating condition is a basic condition (such as ambient temperature standby, low-power heat preservation, or purging), and the operating condition switching command indicates switching to a more complex operating condition with higher temperature requirements (such as preheating or deposition), then the process temperature needs to be increased. Conversely, it needs to be decreased.

[0106] Step S32: If the process temperature required for the target operating condition indicated by the operating condition switching command is greater than the process temperature required for the current operating condition, then determine that the first compensation power and the second compensation power are positive values.

[0107] Therefore, after feedforward compensation, the target power of both the inner and outer heating elements increases, thereby increasing the temperature of the dual-zone substrate heater to meet the process requirements of the target operating conditions.

[0108] Step S33: If the process temperature required for the target operating condition indicated by the operating condition switching command is less than the process temperature required for the current operating condition, then the first compensation power and the second compensation power are determined to be negative values.

[0109] Therefore, after feedforward compensation, the target power of both the inner and outer heating elements is reduced, thereby lowering the temperature of the dual-zone substrate heater to meet the process requirements of the target operating conditions.

[0110] The steps S31 to S33 described above can be performed in step 14, or they can be performed in the aforementioned step S12.

[0111] Understandably, unlike the traditional approach of detecting temperature changes first and then adjusting power (which is a passive, lagging adjustment), the embodiments of this application perform power feedforward compensation within the same control cycle after receiving the operating condition switching command. This is an active, proactive adjustment, and therefore can suppress disturbances in advance. Furthermore, the feedforward compensation can achieve zero delay, thus enabling power adjustment to be completed simultaneously with changes in heat load, fundamentally offsetting the thermal disturbances caused by operating condition switching, and achieving disturbanceless temperature switching.

[0112] Moreover, by combining synchronous reception of operating condition switching commands with zero delay in feedforward compensation, the embodiments of this application can avoid delays in both the initiation and process of feedforward compensation, thereby completely eliminating temperature fluctuations caused by control lag.

[0113] In the embodiments of this application, such as Figure 6 As shown, the temperature control method may also include: When no operating condition switching command is received, closed-loop adjustment is performed based on the temperature difference between the first calculated temperature and the first target temperature to obtain the first base power, and the inner zone heating element is controlled to operate at the first base power; and closed-loop adjustment is performed based on the temperature difference between the second calculated temperature and the second target temperature to obtain the second base power, and the outer zone heating element is controlled to operate at the second base power.

[0114] In other words, closed-loop regulation is performed without power feedforward compensation when no operating condition switching command is received. Closed-loop regulation is performed simultaneously with power feedforward compensation when an operating condition switching command is received.

[0115] In some embodiments, the following steps may be included after step S14: Step K: Within a set continuous time period after the completion of the working condition switching command, control the inner zone heating element to continue working at the first target power, and control the outer zone heating element to continue working at the second target power.

[0116] In other words, such as Figure 6 As shown in Figures (a) and (b), even after the operating condition switch is completed, the inner and outer heating elements continue to operate at the target power after feedforward compensation for a set continuous period after the switch, i.e., closed-loop regulation and power feedforward compensation are maintained. This design helps the temperature reach a steady state and avoids temperature fluctuations caused by sudden power changes.

[0117] The duration can be set to, for example, 5 seconds, but the specific duration can be set according to the actual situation and is not limited here.

[0118] Step L: After setting the continuous duration, if the fluctuation range of the first converted temperature is greater than the preset range, the inner heating element is controlled to continue working at the first target power until the fluctuation range of the first converted temperature is less than the preset range.

[0119] The preset range can be set according to actual conditions, for example, it can be set to (-0.1℃, +0.1℃). If the fluctuation range of the first converted temperature is greater than the preset range, it indicates that the first converted temperature is unstable. Figure 6 As shown in Figure (b), closed-loop regulation and power feedforward compensation are maintained until the first conversion temperature reaches steady state.

[0120] In step M, after setting the continuous duration, if the fluctuation range of the second converted temperature is greater than the preset range, the outer heating element is controlled to continue working at the second target power until the fluctuation range of the second converted temperature is less than the preset range.

[0121] The fluctuation range of the second calculated temperature is greater than the preset range, indicating that the second calculated temperature is unstable. Therefore, as follows... Figure 6 As shown in Figure (b), closed-loop regulation and power feedforward compensation are maintained until the second conversion temperature reaches steady state.

[0122] Step N: After setting the continuous duration, if the fluctuation range of both the first and second converted temperatures is less than the preset range for a continuous period of time, then the inner zone heating element is controlled to operate at the first base power, and the outer zone heating element is controlled to operate at the second base power.

[0123] In other words, if, after step L or step M, the fluctuation ranges of both the first and second converted temperatures are less than the preset range for a continuous period of time, it indicates that both the first and second converted temperatures are in a steady state, and therefore feedforward compensation control is exited. That is, if... Figure 6 As shown in Figures (a) and (b), closed-loop regulation is performed at this time to eliminate the remaining steady-state error, and power feedforward compensation is not performed.

[0124] The set time can be adjusted according to the actual situation, such as 10 consecutive control cycles or 100ms, without any specific limitation.

[0125] In some embodiments, step N may further involve gradually adjusting the first feedforward compensation power to 0 at a set rate within a preset time period, for example, linearly reducing the first feedforward compensation power to 0 within 1 second, so that the first target power is uniformly and gradually adjusted to the first base power. Similarly, the second feedforward compensation power is adjusted so that the second target power is uniformly and gradually adjusted to the second base power. Based on this design, it is possible to gradually exit feedforward compensation control and avoid temperature fluctuations caused by sudden power changes.

[0126] If the first or second converted temperature is still not stable after step M, the closed-loop regulation and power feedforward compensation can continue, that is, the feedforward compensation hold time is extended until the temperature stabilizes before exiting the feedforward compensation control.

[0127] In this embodiment, the heat transfer characteristics of the dual-zone substrate heater may change due to various factors such as installation method, aging degree, and chamber fouling. This can cause deviations between the first compensation power in the first mapping relationship and the second compensation power in the second mapping relationship and the actual required feedforward compensation, thus making it impossible to accurately control the actual temperature to the target temperature. Therefore, as... Figure 7 As shown, during the use of the dual-zone substrate heater, the temperature control system can update the first mapping relationship and the second mapping relationship through the following steps: Step S51: Record the fluctuation range of the first conversion temperature and the fluctuation range of the second conversion temperature.

[0128] Specifically, the temperature control system records the temperature fluctuation amplitude each time the operating conditions change, so as to determine whether the feedforward compensation can stabilize the temperature based on the temperature fluctuation amplitude. If it can, it means that the feedforward compensation is accurate and effective and does not need to be updated; otherwise, it means that the feedforward compensation is inaccurate and needs to be updated.

[0129] Step S52: If the fluctuation range of the first converted temperature under the same target operating conditions and the same temperature exceeds the set allowable fluctuation range for a set number of consecutive times, then adjust the compensation power in the first mapping relationship according to the set adjustment step size. The allowable fluctuation range, the number of consecutive fluctuations, and the adjustment step size can all be set according to actual conditions and are not specifically limited here. For example, if the temperature fluctuation of the first converted temperature exceeds ±1℃ in three consecutive tests under the same operating conditions and temperature, it indicates that the compensation power in the first mapping relationship is not suitable for the current inner zone heating element. Therefore, the compensation power in the first mapping relationship should be fine-tuned by 5% of the current compensation power. Assuming that the temperature fluctuation of the first converted temperature exceeds +1℃ in three consecutive tests under the same operating conditions and temperature, the updated compensation power can be 95% of the original compensation power. Assuming that the temperature fluctuation of the first converted temperature exceeds -1℃ in three consecutive tests under the same operating conditions and temperature, the updated compensation power can be 105% of the original compensation power.

[0130] Step S53: If the fluctuation range of the second converted temperature under the same target operating conditions and the same temperature exceeds the set allowable fluctuation range for a set number of consecutive times, then adjust the compensation power in the second mapping relationship according to the set adjustment step size.

[0131] Step S53 is similar to step S52, so you can refer to the relevant content of step S52, and will not repeat it here.

[0132] Therefore, during the next operating condition switch, the updated compensation power can be used to verify the compensation effect. If the temperature fluctuation is less than the set fluctuation range (e.g., ±0.5℃ or ±1℃), it indicates that the updated compensation power is accurate and usable, and the first and second mapping relationships are updated according to the updated compensation power. If the temperature fluctuation is greater than or equal to the set fluctuation range, it indicates that the compensation power needs to be adjusted according to the set adjustment step size until the updated compensation power is accurate and usable.

[0133] Therefore, based on the above steps, self-learning updates of the first and second mapping relationships can be achieved.

[0134] Moreover, the updatable design of the first and second mapping relationships ensures their long-term effectiveness and automatically adapts to changes in heat transfer characteristics caused by aging of the dual-zone substrate heater and fouling in the chamber, thereby ensuring that the feedforward compensation effect remains stable over the long term.

[0135] In summary, the temperature control method and control system provided in this application employ a composite control architecture of independent control of inner and outer zones and feedforward compensation. This allows for independent control of the temperature in the central region (inner zone) and the edge region (outer zone) of the dual-zone substrate heater. Furthermore, during operating condition switching, targeted power feedforward compensation is simultaneously applied to the inner and outer heating elements to adapt to the thermodynamic characteristics of higher temperatures in the central region and faster heat dissipation in the edge region, and to suppress instantaneous thermal disturbances in both regions, thereby ensuring the temperature uniformity of the entire dual-zone substrate heater. Through full-temperature-range, full-operating-condition feedforward compensation power mapping, precise feedforward compensation at any temperature point under any operating condition can be achieved, thus realizing high-precision, stable temperature control and wafer surface temperature uniformity control across all process scenarios.

[0136] In this embodiment, both the inner and outer zones can employ closed-loop control (such as PI control or PID control). Furthermore, independent closed-loop control and feedforward compensation for the inner and outer zones can work in tandem. The independent closed-loop control is responsible for eliminating steady-state errors and random disturbances, while the feedforward compensation is responsible for offsetting instantaneous heat load changes caused by operating condition switching, preventing temperature drops, overshoot, or oscillations.

[0137] The feedforward compensation in this application embodiment can be dynamically adjusted according to temperature and operating conditions to ensure the compensation effect. However, fixed feedforward compensation cannot cover different operating conditions and temperature points, resulting in large compensation errors for certain temperature points and operating conditions. This significantly reduces the compensation effect and may even have the opposite effect, causing greater temperature fluctuations.

[0138] Therefore, the temperature control method and temperature control system provided in this application can achieve the following technical effects: (1) When switching operating conditions, the temperature control accuracy of the dual-zone substrate heater is significantly improved. For example, in some tests, the coordinated control of independent closed-loop control of inner and outer zones and feedforward compensation can improve the overall temperature control accuracy by more than 5 times compared with the traditional solution.

[0139] (2) The temperature stability of the dual-zone substrate heater is improved during operating condition switching. For example, consider switching from operating condition 1 to operating condition 2 and then back to operating condition 1. Figure 8 and Figure 9As shown, the temperature fluctuation range of both the internal and external heating elements is reduced from 2℃~3℃ in the traditional solution to within 0.5℃, a reduction of over 80%. The temperature fluctuation range of the TC located at the bottom of the ceramic substrate is reduced from 4℃~5℃ in the traditional solution to within 2℃~3℃, a reduction of over 40%. This demonstrates that temperature fluctuations during operating condition switching are significantly suppressed. Furthermore, the temperature recovery time of both the internal and external heating elements is reduced from over 150s in the traditional solution to approximately 30s, a five-fold improvement in recovery speed. This fully meets the temperature stability requirements of 14nm and below semiconductor processes.

[0140] (3) Improved temperature control accuracy and temperature stability can reduce the thermal stress impact on the ceramic substrate (for example, in some tests, it can be reduced by more than 80%), thereby avoiding the ceramic substrate from cracking, which greatly improves the reliability of the dual-zone substrate heater and reduces the replacement cost.

[0141] Meanwhile, improved temperature control accuracy and temperature stability can reduce the frequency of chamber cleaning and maintenance caused by process anomalies.

[0142] (4) Product yield and process consistency are significantly improved: the uniformity of the film thickness generated by the wafer can be improved to meet the requirements of advanced semiconductor process technology; the consistency of process results of different batches of wafers is improved, the process debugging cycle is shortened, and the production efficiency is improved; the product yield is improved, and the production cost is greatly reduced.

[0143] (5) Strong adaptability and low deployment cost: It covers the entire temperature control range (e.g., 50℃~500℃) and various different process conditions, supports power compensation for various different process conditions and multiple process temperature points, and can be adapted to all mainstream thin film deposition processes; it does not require major modifications to the traditional hardware architecture, only the first mapping relationship and the second mapping relationship need to be stored in the traditional temperature control system, and the feedforward control logic needs to be added. The upgrade cost is less than 10% of the traditional temperature control system, and it can be compatible with the traditional temperature control system architecture; the compensation power mapping for the entire temperature range and all operating conditions is very simple, without the need for a complicated modeling process, and is suitable for mass production deployment.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application.

Claims

1. A temperature control method for a dual-zone substrate heater, characterized in that, The dual-zone substrate heater includes a ceramic substrate, an inner zone heating element, and an outer zone heating element. The inner zone heating element and the outer zone heating element are concentrically arranged and spaced apart within the ceramic substrate. The inner zone heating element is used to heat the inner zone of the ceramic substrate, and the outer zone heating element is used to heat the outer zone of the ceramic substrate. The temperature control method includes: The actual first converted temperature and the set first target temperature of the inner zone heating element are obtained, as well as the actual second converted temperature and the set second target temperature of the outer zone heating element. In response to receiving a condition switching command for indicating a switch to a target operating condition, a first compensation power is obtained according to the target operating condition and the first target temperature mapping, and a second compensation power is obtained according to the target operating condition and the second target temperature mapping; The first base power is determined based on the first converted temperature and the first target temperature, and the second base power is determined based on the second converted temperature and the second target temperature. Within the same control cycle of receiving the operating condition switching command, a first target power is obtained based on the first base power and the first compensation power, and the inner zone heating element is controlled to operate at the first target power so that the first converted temperature is adjusted to the first target temperature; and a second target power is obtained based on the second base power and the second compensation power, and the outer zone heating element is controlled to operate at the second target power so that the second converted temperature is adjusted to the second target temperature.

2. The method as described in claim 1, characterized in that, There is a first mapping relationship between the various operating conditions of the dual-zone substrate heater, the various calibrated temperature points within the preset temperature range, and the compensation power of the inner zone heating element; there is a second mapping relationship between the various operating conditions of the dual-zone substrate heater, the various calibrated temperature points within the preset temperature range, and the compensation power of the outer zone heating element. The step of obtaining the corresponding first compensation power based on the mapping between the target operating condition and the first target temperature, and obtaining the corresponding second compensation power based on the mapping between the target operating condition and the second target temperature, includes: If the first target temperature is a calibration temperature point, then the first compensation power is obtained by mapping according to the first mapping relationship based on the target operating conditions and the first target temperature. If the second target temperature is the calibration temperature point, then the second compensation power is obtained by mapping according to the second mapping relationship based on the target operating conditions and the second target temperature.

3. The method as described in claim 2, characterized in that, The step of mapping the target operating condition and the first target temperature to obtain the corresponding first compensation power further includes: If the first target temperature is located between two adjacent calibration temperature points, then the compensation power of the two adjacent calibration temperature points is obtained by mapping according to the first mapping relationship based on the target operating condition and the two adjacent calibration temperature points. The first linear compensation value is calculated based on the temperature difference between the two adjacent calibration temperature points and the first target temperature, and the compensation power of the two adjacent calibration temperature points. The first compensation power is calculated based on the first linear compensation value, the two adjacent calibration temperature points, the first target temperature, and the set nonlinear compensation function. And / or, The step of obtaining the corresponding second compensation power based on the target operating condition and the second target temperature mapping further includes: If the second target temperature is located between two adjacent calibration temperature points, then the compensation power of the two adjacent calibration temperature points is obtained by mapping according to the second mapping relationship based on the target operating condition and the two adjacent calibration temperature points. The second linear compensation value is calculated based on the temperature difference between the two adjacent calibration temperature points and the second target temperature, and the compensation power of the two adjacent calibration temperature points. The second compensation power is calculated based on the second linear compensation value, the two adjacent calibration temperature points, the second target temperature, and the set nonlinear compensation function.

4. The method as described in claim 2 or 3, characterized in that, The temperature control method further includes: If the fluctuation range of the first converted temperature exceeds the set allowable fluctuation range for a set number of consecutive times under the same target operating conditions and temperature, then the compensation power in the first mapping relationship is adjusted according to the set adjustment step size; or... If the fluctuation range of the second converted temperature under the same target operating conditions and the same temperature exceeds the set allowable fluctuation range a certain number of times, then the compensation power in the second mapping relationship is adjusted according to the set adjustment step size.

5. The method according to any one of claims 1-3, characterized in that, The temperature control method further includes: If the process temperature required for the target operating condition indicated by the operating condition switching command is greater than the process temperature required for the current operating condition, then the first compensation power and the second compensation power are determined to be positive values; or, If the process temperature required for the target operating condition indicated by the operating condition switching command is lower than the process temperature required for the current operating condition, then the first compensation power and the second compensation power are determined to be negative values.

6. The method as described in claim 5, characterized in that, The temperature control method further includes: Within a set continuous duration after the execution of the working condition switching command, the inner zone heating element is controlled to continue working at the first target power, and the outer zone heating element is controlled to continue working at the second target power; After the set continuous duration, if the fluctuation range of the first converted temperature is greater than the preset range, then the inner heating element is controlled to continue operating at the first target power until the fluctuation range of the first converted temperature is less than the preset range; and / or, After the set continuous duration, if the fluctuation range of the second converted temperature is greater than the preset range, then the outer heating element is controlled to continue operating at the second target power until the fluctuation range of the second converted temperature is less than the preset range; and / or, After the set continuous duration, if the fluctuation range of both the first and second converted temperatures is less than the preset range for a continuous period of time, then the inner zone heating element is controlled to operate at the first base power, and the outer zone heating element is controlled to operate at the second base power.

7. The method as described in claim 1, characterized in that, The step of determining the first base power based on the first converted temperature and the first target temperature, and determining the second base power based on the second converted temperature and the second target temperature, includes: Closed-loop adjustment is performed based on the temperature difference between the first converted temperature and the first target temperature to obtain the first base power; Closed-loop regulation is performed based on the temperature difference between the second converted temperature and the second target temperature to obtain the second base power.

8. The method as described in claim 1, characterized in that, The temperature control method further includes: When no operating condition switching command is received, a closed-loop adjustment is performed based on the temperature difference between the first converted temperature and the first target temperature to obtain a first base power, and the inner zone heating element is controlled to operate at the first base power; and a closed-loop adjustment is performed based on the temperature difference between the second converted temperature and the second target temperature to obtain a second base power, and the outer zone heating element is controlled to operate at the second base power.

9. The method as described in claim 1, characterized in that, Obtaining the actual first converted temperature of the inner zone heating element and the actual second converted temperature of the outer zone heating element includes: Obtain the operating electrical parameters of the inner zone heating element and the outer zone heating element; The resistance of the inner heating element is calculated based on its working electrical parameters, and the first converted temperature is obtained based on the resistance of the inner heating element and its temperature coefficient of resistance. The resistance of the outer heating element is calculated based on its operating electrical parameters, and the second converted temperature is obtained based on the resistance and temperature coefficient of resistance of the outer heating element.

10. A temperature control system for a dual-zone substrate heater, characterized in that, The dual-zone substrate heater includes a ceramic substrate, an inner zone heating element, and an outer zone heating element. The inner zone heating element and the outer zone heating element are concentric and spaced apart within the ceramic substrate. The inner zone heating element is used to heat the inner zone of the dual-zone substrate heater, and the outer zone heating element is used to heat the outer zone of the dual-zone substrate heater. The temperature control system is communicatively connected to the operating condition control system of the dual-zone substrate heater. The temperature control system is used to synchronously receive the operating condition switching command when the operating condition control system issues the operating condition switching command. The temperature control system is used to execute the temperature control method as described in any one of claims 1 to 9.

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