Temperature control method for wafer heat treatment and millisecond annealing treatment system
By employing a dual-mode control strategy during the anchoring and transition stages, combined with a water window filter structure and high-frequency sampling, the challenge of temperature measurement and control during millisecond-level annealing was solved, achieving precise control of wafer temperature and process consistency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING E TOWN SEMICON TECH CO LTD
- Filing Date
- 2026-01-22
- Publication Date
- 2026-04-17
AI Technical Summary
Existing technologies face challenges in temperature measurement and control during millisecond-level annealing processes, particularly due to slow sensor response and accumulated initial state errors, leading to poor process consistency and decreased yield.
A dual-mode control strategy is adopted, which eliminates intermediate temperature errors during the anchoring stage through closed-loop feedback and performs open-loop control using pre-stored calibration data during the transition stage. Combined with a water window filter structure and high-frequency sampling, precise temperature control is achieved.
It significantly improves the process repeatability and consistency of peak temperature, solves the problems of insufficient response and reference drift in traditional control methods, and ensures precise control of wafer temperature.
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Figure CN121888901A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of semiconductor technology, and in particular to a temperature control method for wafer thermal processing and a millisecond-level annealing system. Background Technology
[0002] As semiconductor integrated circuit process nodes continue to shrink, the requirements for impurity activation and lattice damage repair in wafers are becoming increasingly stringent. In order to maximize the suppression of impurity diffusion and form ultra-shallow junctions while activating dopants, millisecond-level annealing or flash annealing techniques are widely used.
[0003] Typical millisecond-level annealing processes employ a "dual-temperature heating" strategy: First, the wafer is preheated to an intermediate temperature using a continuous heat source (such as a halogen lamp or a continuous arc lamp), which is typically below the threshold for significant impurity diffusion. Then, a high-power flash lamp (such as a xenon arc lamp) is used to irradiate the wafer surface for an extremely short time (typically less than 10 milliseconds), causing its surface temperature to instantly jump to a peak temperature (e.g., above 1100°C), and then rapidly cool it before the heat is conducted into the wafer's interior. This technique utilizes the wafer's own thermal capacity as a heat sink, achieving the coexistence of a high surface temperature and a low substrate temperature. Summary of the Invention
[0004] This disclosure provides a temperature control method for wafer thermal processing and a millisecond-level annealing system to solve or alleviate one or more technical problems in the prior art.
[0005] In a first aspect, this disclosure provides a temperature control method for wafer thermal processing. The method is applied to a thermal processing chamber, wherein the chamber includes a lower heating module, an upper flash heating module, and a temperature measurement system. The temperature measurement system is equipped with a water window filter structure disposed between the wafer and the light source to filter out light radiation interference in non-temperature-measuring bands. The method includes the following steps: Anchoring phase: The lower heating module is activated to perform background heating on the wafer; the first real-time temperature of the wafer is collected using a temperature measurement system, and the controller adjusts the power of the lower heating module in a closed-loop feedback manner based on the deviation between the first real-time temperature and the preset intermediate temperature until the wafer temperature stabilizes at the intermediate temperature. Jump phase: After the wafer temperature stabilizes at the intermediate temperature, the upper flash heating module is triggered; the controller determines the output power of the upper flash heating module according to the pre-stored energy-temperature rise calibration data, and controls the upper flash heating module to output millisecond-level light pulses in open-loop mode to heat the wafer to the target peak temperature; Verification phase: During the operation of the upper flash heating module, the second real-time temperature of the wafer is recorded by high-frequency sampling of the temperature measurement system, and the actual peak temperature is captured to verify the process results.
[0006] Secondly, this disclosure provides a millisecond-level annealing processing system, including: Processing chambers are used to house the wafers; A continuous arc lamp is used for background heating of the wafer; The upper flash arc lamp is used to heat the wafer with millisecond-level pulses; A temperature measuring device, wherein a water window structure is provided in its optical path, the water window structure being configured to utilize the absorption characteristics of water to filter out signals of a specific temperature measurement band directly radiated by the light source; and The system controller is electrically connected to the lower continuous arc lamp, the upper flashing arc lamp, and the temperature measuring device; The system controller is configured to execute the temperature control method of the first aspect.
[0007] The beneficial effects of the technical solution provided in this disclosure include at least the following: The continuous heating process is decoupled in the time domain into an anchoring phase and a transition phase. By employing closed-loop feedback during the long anchoring phase, random errors in intermediate temperatures are eliminated. During the millisecond-level transition phase, an open-loop control based on calibration data, combined with a locking strategy for the heating module, avoids control oscillations caused by sensor response lag. This dual-modal strategy of steady-state closed-loop environmental reference + transient open-loop environmental increment effectively solves the problems of insufficient response in traditional fully closed-loop control and reference drift in fully open-loop control, significantly improving the process repeatability and consistency of peak temperatures.
[0008] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description
[0009] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments provided according to this disclosure and should not be construed as limiting the scope of this disclosure.
[0010] Figure 1 This is a schematic flowchart of a temperature control method for wafer thermal processing according to an embodiment of the present disclosure; Figure 2 This is a graph showing the change of wafer temperature over time according to an embodiment of the present disclosure; Figure 3 yes Figure 2 A magnified view of the middle timeline in the range of 4.83 seconds to 4.87 seconds; Figure 4This is a block diagram of an electronic device used to implement the temperature control method of the embodiments of this disclosure. Detailed Implementation
[0011] The present disclosure will now be described in further detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.
[0012] Furthermore, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that this disclosure can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art have not been described in detail in order to highlight the main points of this disclosure.
[0013] In practical applications, millisecond-level annealing faces significant challenges in temperature measurement and control: First, there is control lag on an extremely short timescale. The flash heating process typically lasts only a few milliseconds. Traditional temperature control systems rely on closed-loop logic of "measurement-feedback-regulation" (such as PID control). However, a few milliseconds is far smaller than the response time constant of most heating power supplies and sensors. This means that at the instant the flash occurs, the control system simply does not have enough time to adjust the lamp power based on the measured temperature.
[0014] Second, there is the accumulation of initial state errors. Since the flash phase can only operate in open loop (i.e., outputting a preset energy), the final peak temperature (Tpeak) depends not only on the energy output by the flash lamp but also, more strictly, on the intermediate temperature (Tmid) at the moment of triggering. In related technologies, if Tmid is unstable during the preheating phase, or if the heating lamp is disturbed and fluctuates at the moment of flash triggering, these initial errors will directly add to the final Tpeak. For example, if Tmid deviates by 5°C, even with extremely precise flash energy, Tpeak will deviate accordingly, leading to poor process consistency between wafers and, in severe cases, a decrease in yield.
[0015] This disclosure provides a millisecond-level annealing system and its temperature control method. The system aims to solve the problem of precise temperature control and measurement of semiconductor wafers within extremely short timescales (milliseconds). A typical processing system mainly includes a processing chamber, a lower heating module, an upper flash heating module, a temperature measuring device, and a system controller. The processing chamber accommodates the wafer; the lower continuous arc lamp is used for background heating of the wafer; the upper flash arc lamp is used for millisecond-level pulse heating of the wafer; the temperature measuring device has a water window structure in its optical path, configured to filter out specific temperature-measuring wavelength signals directly radiated by the light source using the absorption characteristics of water; the system controller is electrically connected to the lower continuous arc lamp, the upper flash arc lamp, and the temperature measuring device; the system controller is configured to execute the temperature control method.
[0016] In one possible implementation, the lower heating module is located below the wafer, preferably using a continuous wave (CW) arc lamp array. Its main function is to provide long-pulse background heating to the wafer, slowly raising it from room temperature and stabilizing it at a preset intermediate temperature (Tmid, for example, 600°C to 900°C).
[0017] In one possible implementation, the upper flash heating module is located above the wafer, preferably employing a high-power-density pulsed flash arc lamp array. Its function is to output high-energy light pulses for an extremely short time (e.g., millisecond-level pulse durations of 0.1 ms to 10 ms), causing the wafer surface temperature to rapidly jump from an intermediate temperature to a target peak temperature (Tpeak, e.g., 1100°C to 1300°C) to achieve shallow junction annealing or impurity activation.
[0018] In one possible implementation, the specific temperature measurement band is the band around 1450 nm; the temperature measuring device is a narrowband pyrometer whose response wavelength is limited to 1450 nm.
[0019] In one possible implementation, the water window structure comprises two layers of quartz glass and a layer of deionized water flowing between them, the thickness of which is configured to completely absorb the 1450nm wavelength light emitted by the arc lamp.
[0020] To achieve accurate temperature measurement in environments with strong light interference, this embodiment incorporates a specially designed water window filter structure between the wafer and the light source (particularly the upper flash heating module) and the optical path of the temperature measurement device. This water window filter structure serves not only as a physical isolation barrier but also as a crucial optical filtering component. Specifically, the water window filter structure comprises two layers of optical-grade quartz glass and a layer of deionized water flowing between the two glass layers. The thickness of this water layer is precisely designed (e.g., 2mm to 5mm), utilizing the strong absorption characteristics of liquid water in a specific infrared band. It is configured to completely absorb and block the radiation signal of the specific temperature measurement band emitted by the arc lamp (including the lower heating module and the upper flash heating module). In this embodiment, the specific temperature measurement band is selected as the band around 1450nm.
[0021] In conjunction with the aforementioned water window filtering structure, a narrowband pyrometer with a response wavelength strictly limited to 1450nm was selected as the temperature measurement device. Since the 1450nm light emitted by the light source is physically blocked by the water layer in the water window, the 1450nm signal received by the pyrometer detector essentially originates only from the thermal radiation of the wafer itself. This hardware design physically filters out light radiation interference with wavelengths less than 1400nm and the 1450nm interference directly emitted by the light source, significantly improving the signal-to-noise ratio and providing a clean signal source for subsequent control algorithms.
[0022] In one implementation, the system controller of the aforementioned millisecond-level annealing system is electrically connected to the lower heating module, the upper flash heating module, and the temperature measuring device, and is configured to execute a bimodal control logic that decouples the process in the time domain into an "anchoring phase" and a "jump phase." For example... Figure 1 As shown, the control method specifically includes the following steps: S101, Anchoring Stage: The lower heating module is started to perform background heating on the wafer; the first real-time temperature of the wafer is collected using a temperature measurement system, and the controller performs closed-loop feedback adjustment of the power of the lower heating module based on the deviation between the first real-time temperature and the preset intermediate temperature until the wafer temperature stabilizes at the intermediate temperature.
[0023] In this embodiment of the disclosure, the system enters the anchoring phase at the start of the process. During this phase, the system controller activates the lower heating module to perform background heating on the wafer. Since the main purpose of this phase is to establish an extremely stable thermal reference, and the duration is relatively long (typically 8 to 20 seconds), the system has sufficient response time for feedback adjustment.
[0024] During this period, the temperature measurement device acquires the first real-time temperature of the wafer at a first sampling frequency (e.g., low-frequency sampling from 10Hz to 100Hz). The system controller compares this first real-time temperature with a preset intermediate temperature (Tmid) in real time. Based on the deviation, it adjusts the output power of the lower heating module in real time using a PID (proportional-integral-derivative) algorithm or other closed-loop control algorithm. Through this closed-loop feedback adjustment, the system can eliminate the influence of variables such as chamber environment fluctuations and differences in the initial state of the wafer until the wafer temperature is precisely "anchored" at the intermediate temperature (Tmid). This step ensures a high degree of consistency in the "starting point" of subsequent millisecond-level jumps.
[0025] S102, Jumping Stage: After the wafer temperature stabilizes at the intermediate temperature, the upper flash heating module is triggered; the controller determines the output power of the upper flash heating module according to the pre-stored energy-temperature rise calibration data, and controls the upper flash heating module to output millisecond-level light pulses in open-loop mode to heat the wafer to the target peak temperature.
[0026] In this embodiment, the system enters a transition phase when the wafer temperature is detected to have stabilized at an intermediate temperature or when a process trigger command is received. Because the upper flash heating module operates for an extremely short time (milliseconds), traditional closed-loop feedback cannot respond in a timely manner. Therefore, this embodiment employs a unique "lock-in + open-loop" strategy at this stage.
[0027] First, the system controller immediately executes a "freeze" operation the instant the upper flash heating module is triggered, or when the temperature measurement device detects a temperature rise rate exceeding a preset threshold (indicating that the flash has started). Specifically, the controller freezes the closed-loop feedback regulation for the lower heating module and locks the current power output value of the lower heating module. This logic is crucial because it prevents the PID controller of the lower heating module from attempting to reduce power due to misinterpretation of the sharp temperature rise caused by the flash, thereby avoiding artificially induced temperature drops.
[0028] Subsequently, the system controller controls the flash heating module to output light pulses in open-loop mode. At this time, the power or energy output by the flash lamp is not determined by the real-time temperature, but by the pre-stored "energy-temperature rise calibration data". Based on the current intermediate temperature (Tmid) and the target peak temperature (Tpeak), the controller consults the calibration data, calculates the required energy increment, and drives the flash lamp to release pulses of the corresponding voltage, thereby heating the wafer to the target peak temperature.
[0029] During this transition phase, to capture transient temperature changes, the sampling frequency of the temperature measurement device automatically switches to a second sampling frequency higher than the first sampling frequency. Preferably, the second sampling frequency ranges from 1 kHz to 2 kHz. Using this high-frequency sampling, the system can completely record the temperature rise curve of the wafer within milliseconds and the second real-time temperature (i.e., the actual peak temperature reached).
[0030] S103, Verification Stage: During the operation of the upper flash heating module, the second real-time temperature of the wafer is recorded by high-frequency sampling of the temperature measurement system, and the actual peak temperature is captured to verify the process results.
[0031] In this embodiment of the disclosure, although the transition phase is an open-loop control, the system uses a second real-time temperature recorded by high-frequency sampling to verify the process results. This data is used to determine whether the wafer has reached the Tpeak required by the process and can be used for Run-to-Run (R2R) control, that is, to use the deviation data of the current wafer to correct the calibration parameters of the next wafer, but no real-time intervention is performed during the millisecond-level flash process of the current wafer.
[0032] According to the scheme of the present disclosure, the absolute accuracy of Tmid is ensured by closed-loop control, and the relative accuracy of temperature change is ensured by calibration data. The combination of the two achieves accurate control of Tpeak indirectly but reliably without the need for millisecond-level real-time feedback, effectively solving the technical bottleneck that the sensor response speed is slower than the heating speed.
[0033] In one implementation, the accuracy of the aforementioned transition phase is highly dependent on pre-stored calibration data. This embodiment obtains this data in advance through the following standardized calibration steps: Before the product wafer is processed, a standard calibration wafer (dummy wafer) with the same optical and thermal properties as the product wafer is placed in the thermal processing chamber. First, the standard calibration wafer is heated and stabilized at the same intermediate temperature (Tmid) as the process using the lower heating module. While maintaining this background temperature, multiple different preset voltage values (or energy settings) are applied to the upper flash heating module to trigger the flash.
[0034] For each flash, the system uses the same temperature measurement device to record the temperature rise response of the standard calibration wafer through the water window filter structure. Through this series of tests, the system establishes and stores the correlation curve between the "input voltage of the upper flash heating module" and the "wafer temperature rise amplitude (ΔT)" or "final peak temperature (Tpeak)". This correlation curve constitutes the aforementioned "energy-temperature rise calibration data". In actual production, the controller only needs to look up a table to determine the required output voltage to achieve a specific temperature rise.
[0035] In one implementation, this embodiment employs a measured mapping method that does not rely on blackbody radiation theory to convert the signal collected by the temperature measuring device into a temperature value.
[0036] Specifically, the temperature measurement device acquires the intensity of the radiation response signal (usually a voltage signal or count value) in the 1450nm band, transmitted through the water window filter structure and received by the detector. The system controller has a pre-built "signal-temperature mapping model." This model is constructed based on measured signal response data from a standard calibrated wafer at multiple preset temperature points under an optical path environment identical to the actual process (i.e., including actual hardware interference such as the water window and reflector).
[0037] When constructing this model, the actual temperature of the wafer is obtained through thermocouple wafers or other standard temperature measurement methods, and the output signal of the pyrometer of this system at the corresponding temperature is recorded. Using these discrete measured data points, numerical correspondences or fitting curves are constructed through numerical fitting (such as polynomial fitting). In actual processes, the controller uses this preset model to process the intensity of the acquired radiation response signal to directly obtain the real-time temperature of the wafer. This method "packages" all complex and difficult-to-calculate physical factors, such as the transmittance of the water window, the effective emissivity of the wafer, and the reflectivity of the chamber, into the measured data, achieving accurate temperature measurement in engineering without disclosing specific fitting formulas or correction coefficients.
[0038] It should be noted that traditional temperature measurement algorithms based on Planck's law require accurate knowledge of the system's effective emissivity. However, effective emissivity is affected by various factors such as water window thickness, water purity, and the degree of quartz glass aging, making theoretical calculation difficult. This embodiment employs a "measured mapping method" that establishes a direct "signal-temperature" lookup table through pre-calibration of a standard wafer. Because this mapping table is obtained under the exact same optical path as the actual process, it naturally includes all systematic error factors such as water window absorption and optical path loss. Therefore, in actual temperature measurement, there is no need to separately estimate or correct these parameters. Even if the water window transmittance changes slightly due to long-term use, the mapping table only needs to be updated by rerunning the calibration process. This method greatly reduces the complexity of the algorithm and gives the system strong engineering adaptability, avoiding temperature measurement deviations caused by incorrect estimation of theoretical parameters.
[0039] To verify the effectiveness of the "anchor-jump" control method described in this technical solution, Figure 2 A graph showing the wafer temperature change over time during a complete process according to an embodiment of the present disclosure is presented. Figure 3 for Figure 2The magnified schematic diagram of the mid-time axis in the range of 4.83 seconds to 4.87 seconds highlights the transient thermal response during the millisecond-level transition phase.
[0040] like Figure 2 and Figure 3 As shown, the horizontal axis of the coordinate system represents time (in seconds), and the vertical axis represents temperature (in degrees Celsius). The graph contains two temperature measurement curves: The upper temperature measurement curve (corresponding to the red curve in the original color image): collected by the first high temperature meter through the water window filter structure and aligned with the upper surface of the wafer, representing the surface temperature of the light-receiving surface of the wafer.
[0041] The lower temperature profile (corresponding to the blue profile in the original color image): acquired by a second pyrometer aligned with the lower surface of the wafer, representing the body temperature or back surface temperature of the wafer.
[0042] Anchoring phase (approximately 3.0s - 4.84s) Reference Figure 2 Before time t=4.84s, the system is in the background heating phase dominated by the lower heating module. During this period, the system controller performs closed-loop feedback regulation.
[0043] Curve characteristics: As shown in the figure, the upper temperature measurement curve and the lower temperature measurement curve essentially overlap at this stage.
[0044] Physical significance: This coincidence indicates that, under slow-heating background conditions, the thermal diffusion rate inside the wafer is sufficient to balance the temperature difference between the upper and lower surfaces, and the wafer as a whole is in thermal equilibrium. The temperature measured at this point (approximately 700°C) is the precise intermediate temperature (Tmid). This high degree of consistency verifies that closed-loop control effectively eliminates environmental interference, providing a unified and accurate "thermal jump point" for subsequent flashes.
[0045] Transition phase (approximately 4.84s - 4.85s) Reference Figure 3 (Enlarged view) At around t=4.84s, the upper flash heating module is triggered, and the system switches to open-loop control mode.
[0046] At this instant, the two curves diverge significantly and briefly. The upper temperature measurement curve rises vertically at an extremely high rate, reaching a peak temperature (Tpeak) of approximately 1300°C in a very short time (milliseconds); while the lower temperature measurement curve also shows an upward trend, but its amplitude is much smaller than that of the upper temperature measurement curve, only rising to about 800°C, and the response is delayed.
[0047] This separation phenomenon accurately reflects the characteristics of millisecond-level annealing. Due to the extremely short flash pulse (less than the wafer's thermal conduction time constant), the enormous light energy is primarily deposited on a thin layer on the upper surface of the wafer, causing a dramatic temperature jump on the surface, while the heat has not yet been conducted to the back side through the wafer's thickness. At this point, the upper temperature measurement curve represents the junction temperature of process interest, while the lower temperature measurement curve represents the wafer's substrate temperature. This invention utilizes high-frequency sampling to accurately capture this instantaneous Tpeak, demonstrating that the system's output based on calibration data is accurate in open-loop mode.
[0048] Verification and cooling phase (after 4.85s) Reference Figure 3 and Figure 2 The latter half, after the flash pulse ends: Curve characteristics (re-overlapping): The upper temperature measurement curve decays rapidly after reaching its peak, exhibiting a steep downward slope; the lower temperature measurement curve shows a slow rise or a smooth transition. After approximately t = 4.86 s, the two curves tend to overlap again and then slowly decline with the same slope (e.g., Figure 2 (As shown in the range of t=5.0s to 9.0s).
[0049] The rapid drop in the upper temperature measurement curve is not primarily due to radiative heat dissipation, but rather to a dramatic thermal diffusion of heat from the high-temperature surface to the low-temperature bulk. When the two curves overlap again, it indicates that the temperature difference between the upper and lower surfaces of the wafer has disappeared, and internal thermal equilibrium has been restored.
[0050] In summary, Figure 2 and Figure 3 The characteristics of the control method presented in this scheme are clearly demonstrated: before the intermediate temperature (Tmid), closed-loop control ensures a high degree of temperature consistency between the upper and lower surfaces; during the flash, open-loop control achieves precise temperature jumps on the surface; and after the process is completed, the system quickly returns to thermal equilibrium. This specific temperature curve shape is a direct manifestation of the synergistic effect of the hardware architecture (water window filter) and control logic (dual-mode switching) of this disclosure.
[0051] This disclosure also provides a temperature control device for millisecond-level thermal processing of wafers. The device is applied to a thermal processing chamber, wherein the chamber includes a lower heating module, an upper flash heating module, and a temperature measurement system. The temperature measurement system is configured with a water window filter structure disposed between the wafer and the light source to filter out light radiation interference in non-temperature-measuring bands. The device includes the following modules: The first control module is used to start the lower heating module to perform background heating on the wafer; the first real-time temperature of the wafer is collected by the temperature measurement system, and the controller performs closed-loop feedback adjustment of the power of the lower heating module based on the deviation between the first real-time temperature and the preset intermediate temperature until the wafer temperature stabilizes at the intermediate temperature. The second control module is used to trigger the upper flash heating module after the wafer temperature stabilizes at the intermediate temperature. The controller determines the output power of the upper flash heating module based on the pre-stored energy-temperature rise calibration data and controls the upper flash heating module to output millisecond-level light pulses in open-loop mode to heat the wafer to the target peak temperature. The third control module is used to record the second real-time temperature of the wafer using high-frequency sampling of the temperature measurement system during the operation of the upper flash heating module, and to capture the actual peak temperature to verify the process results.
[0052] The specific functions and examples of each module and submodule of the apparatus in this disclosure can be found in the relevant descriptions of the corresponding steps in the above method embodiments, and will not be repeated here.
[0053] Figure 4 This is a structural block diagram of an electronic device according to an embodiment of the present disclosure. Figure 4 As shown, the electronic device includes a memory 410 and a processor 420. The memory 410 stores a computer program that can run on the processor 420. There can be one or more memories 410 and processors 420. The memory 410 can store one or more computer programs, which, when executed by the electronic device, cause the electronic device to perform the methods provided in the above-described method embodiments. The electronic device may also include a communication interface 430 for communicating with external devices and performing data exchange and transmission.
[0054] If the memory 410, processor 420, and communication interface 430 are implemented independently, they can be interconnected via a bus to communicate with each other. This bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. This bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 4 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.
[0055] Optionally, in a specific implementation, if the memory 410, processor 420 and communication interface 430 are integrated on a single chip, the memory 410, processor 420 and communication interface 430 can communicate with each other through an internal interface.
[0056] It should be understood that the aforementioned processor can be a Central Processing Unit (CPU), or other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. General-purpose processors can be microprocessors or any conventional processor. It is worth noting that the processor can be a processor supporting Advanced Reduced Instruction Set Machines (ARM) architecture.
[0057] Further, optionally, the aforementioned memory may include read-only memory and random access memory, and may also include non-volatile random access memory. The memory may be volatile or non-volatile, or may include both. Non-volatile memory may include read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory may include random access memory (RAM), which serves as an external cache. Many forms of RAM are available by way of example, but not limitation. Examples include Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct RAMBUS RAM (DR RAM).
[0058] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this disclosure are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line, DSL) or wireless (e.g., infrared, Bluetooth, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer, or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., Digital Versatile Discs (DVDs)), or semiconductor media (e.g., Solid State Disks (SSDs)). It is worth noting that the computer-readable storage media mentioned in this disclosure can be non-volatile storage media; in other words, it can be non-transient storage media.
[0059] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.
[0060] In the description of the embodiments of this disclosure, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.
[0061] In the description of the embodiments disclosed herein, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone.
[0062] In the description of embodiments of this disclosure, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.
[0063] The above description is merely an exemplary embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.
Claims
1. A temperature control method for wafer heat treatment, wherein the method is applied to a heat treatment chamber, wherein, The chamber includes a lower heating module, an upper flash heating module, and a temperature measurement system; the temperature measurement system is equipped with a water window filter structure disposed between the wafer and the light source to filter out light radiation interference in non-temperature-measuring bands; The method includes the following steps: Anchoring phase: The lower heating module is activated to perform background heating on the wafer; the temperature measurement system is used to collect the first real-time temperature of the wafer, and the controller performs closed-loop feedback adjustment of the power of the lower heating module based on the deviation between the first real-time temperature and the preset intermediate temperature until the wafer temperature stabilizes at the intermediate temperature; Jump phase: After the wafer temperature stabilizes at the intermediate temperature, the upper flash heating module is triggered; the controller determines the output power of the upper flash heating module according to the pre-stored energy-temperature rise calibration data, and controls the upper flash heating module to output millisecond-level light pulses in open-loop mode to heat the wafer to the target peak temperature; Verification phase: During the operation of the upper flash heating module, the second real-time temperature of the wafer is recorded by high-frequency sampling of the temperature measurement system, and the actual peak temperature is captured to verify the process results.
2. The method according to claim 1, wherein, The non-temperature-measuring band optical radiation interference includes radiation with wavelengths less than 1400nm from the lower heating module and the upper flash heating module; the temperature measurement system is configured to detect only radiation signals with a narrow band wavelength of 1450nm, and the water window filter structure includes a flowing water layer, which is used to absorb and block the 1450nm band radiation emitted by the light source, so that the 1450nm signal received by the temperature measurement system originates from the thermal radiation of the wafer itself.
3. The method according to claim 1, wherein, During the anchoring phase, the temperature measurement system operates at a first sampling frequency; during the transition phase, the temperature measurement system switches to a second sampling frequency higher than the first sampling frequency, the second sampling frequency being in the range of 1 kHz to 2 kHz.
4. The method according to claim 1, wherein, The pre-stored energy-temperature rise calibration data is obtained in advance through the following calibration steps: A standard calibration wafer is placed in the heat treatment chamber; The standard calibration wafer is heated and stabilized at the intermediate temperature; Multiple different preset voltage values are applied to the upper flash heating module to trigger the flash respectively; For each flash, the temperature rise response of the standard calibration wafer is recorded through the water window filter structure using the same temperature measurement system. Establish and store the curve showing the relationship between the input voltage of the flash heating module and the wafer temperature rise or final peak temperature, as the calibration data.
5. The method according to claim 1, wherein, The triggering logic for the transition phase is as follows: When the temperature rise rate detected by the temperature measurement system exceeds the preset threshold, or when the trigger command of the upper flash heating module is executed, the controller immediately freezes the closed-loop feedback adjustment for the lower heating module and locks the power output of the lower heating module until the transition phase ends.
6. The method according to claim 1, wherein, The lower heating module is a continuous wave arc lamp array, and the upper flash heating module is a pulse flash arc lamp array; The duration of the anchoring phase is 8 to 20 seconds, and the pulse duration of the transition phase is in the millisecond range.
7. The method according to claim 1, wherein, The acquisition of the first real-time temperature of the wafer using the temperature measurement system includes: The intensity of the radiative response signal in the 1450nm band is collected, transmitted through the water window filter structure and received by the detector. The intensity of the radiation response signal is processed using a preset signal-temperature mapping model to directly obtain the real-time temperature of the wafer; The signal-temperature mapping model is a numerical correspondence or fitting curve constructed based on the measured signal response data of a standard calibration wafer under the same optical path environment as the wafer at multiple preset temperature points.
8. A millisecond-level annealing system, comprising: Processing chambers are used to house the wafers; A continuous arc lamp is used for background heating of the wafer; The upper flash arc lamp is used to heat the wafer with millisecond-level pulses; A temperature measuring device, wherein a water window structure is provided in the optical path, the water window structure being configured to filter out specific temperature measurement band signals directly radiated by the light source by utilizing the absorption characteristics of water. as well as The system controller is electrically connected to the lower continuous arc lamp, the upper flashing arc lamp, and the temperature measuring device; The system controller is configured to perform the temperature control method as described in any one of claims 1 to 7.
9. The system of claim 8, wherein, The specific temperature measurement band is the band around 1450nm; the temperature measuring device is a narrowband pyrometer, and its response wavelength is limited to 1450nm.
10. The system as described in claim 8, characterized in that, The water window structure comprises two layers of quartz glass and a layer of deionized water flowing between them. The thickness of the water layer is configured to completely absorb the 1450nm wavelength light emitted by the arc lamp.