A semiconductor thin film heating regulation method and system based on multi-sensor feedback

Abstract

This application provides a semiconductor thin film heating control method and system based on multi-sensor feedback, relating to the field of semiconductor technology. The method calculates the heat flux divergence at each measuring point by using the tangential heat flux density of adjacent measuring points, obtaining the heat accumulation distribution. It also uses the time difference of arrival (TDOA) of elastic wave signals to determine the distribution of thermal stress release points. The consistency between the heat accumulation distribution and the thermal stress release point distribution at the same measuring point determines the confidence level of thermal imbalance at each measuring point, thereby identifying local thermal imbalance regions. The method determines the injection heat flux reduction amount of the heating unit based on the heat accumulation rate of the local thermal imbalance region, and uses the thermal stress release intensity of the local thermal imbalance region to gradient-modulate the injection heat flux reduction amount, obtaining a target injection heat flux adapted to the chip coating temperature uniformity control. The heating unit is driven by the target injection heat flux. This application can achieve dynamic identification of local thermal imbalance regions in semiconductor thin films, thereby improving the uniformity of the thin film temperature field distribution.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and more specifically, to a method and system for controlling the heating of semiconductor thin films based on multi-sensor feedback. Background Technology

[0002] As integrated circuit manufacturing processes develop towards higher density, higher precision, and higher consistency, semiconductor technology plays an increasingly important role in chip fabrication, thin film deposition, and device performance control. Chip coating temperature control, as a key step in semiconductor manufacturing, directly affects the quality of thin film crystallization, film thickness consistency, and device electrical performance. By controlling a stable and uniform temperature field, the impact of process fluctuations on the film structure can be reduced, providing important process support for high-quality chip manufacturing.

[0003] In existing technologies, semiconductor thin films typically have large areas, thin thicknesses, and complex heat conduction paths during heating. They are easily affected by factors such as edge heat dissipation, local material differences, and uneven heating power distribution, resulting in local hot spots or low-temperature regions. Current temperature control methods mostly rely on feedback control based on the temperature of limited measurement points or overall temperature changes, making it difficult to identify the forming and expanding local thermal imbalance regions inside the thin film in a timely manner. When local temperature anomalies continue to expand, they can easily lead to thermal stress concentration, crystal structure changes, or inconsistent film properties, thereby affecting the manufacturing quality of devices. Therefore, how to achieve dynamic identification of local thermal imbalance regions in semiconductor thin films, thereby improving the uniformity of the film temperature field distribution, has become a challenge for the industry. Summary of the Invention

[0004] This application provides a method and system for controlling the heating of semiconductor thin films based on multi-sensor feedback, which can dynamically identify local thermal imbalance regions of semiconductor thin films, thereby improving the uniformity of the temperature field distribution of the thin film.

[0005] In a first aspect, this application provides a semiconductor thin film heating control method based on multi-sensor feedback, the semiconductor thin film heating control method comprising the following steps: The tangential heat flux density of the film surface at each measuring point is obtained by a heat flux density sensor array on the wafer carrier surface, and the elastic wave signal excited by thermal stress is simultaneously obtained by an acoustic emission sensor coupled to the base. The heat flux divergence of each measuring point is calculated based on the tangential heat flux density of the membrane surface of adjacent measuring points to obtain the heat storage distribution. The arrival time difference of the elastic wave signal is used to locate the distribution of thermal stress release points. The thermal imbalance confidence level of each measuring point is determined based on the consistency between the heat storage distribution and the thermal stress release point distribution at the same measuring point. Measuring points with thermal imbalance confidence levels exceeding a preset threshold are labeled as local thermal imbalance areas. The amount of heat flow reduction of the heating unit is determined based on the heat accumulation rate of the local thermal imbalance region, and the amount of heat flow reduction is gradient-modulated by the thermal stress release intensity of the local thermal imbalance region to obtain the target heat flow that is adapted to the uniformity control of chip coating temperature. The heating unit is driven by the target injected heat flow, so that the heat accumulation rate and thermal stress release intensity of the local thermal imbalance region are reduced to within the corresponding threshold.

[0006] In this embodiment, the heat flux divergence of each measuring point is calculated based on the tangential heat flux density of the membrane surface at adjacent measuring points to obtain the heat storage distribution, specifically including: The heat flux adjacency relationship of the measuring points is established based on the arrangement of each measuring point in the heat flux density sensor array on the wafer carrier surface; Based on the heat flux adjacency relationship of the measuring points, the directional difference of the tangential heat flux density on the membrane surface of adjacent measuring points is extracted to obtain the tangential heat flux difference characteristics; By extracting the divergence features of the heat flow convergence degree at each measuring point through the tangential heat flow difference characteristics, the heat flow divergence features of each measuring point are obtained. Based on the heat flux divergence characteristics of each measuring point, the heat concentration area of ​​the wafer bearing surface is distributed and mapped to obtain the heat storage distribution.

[0007] In this embodiment, the time difference of arrival (TDOA) of the elastic wave signal is used to determine the distribution of thermal stress release points, specifically including: The elastic wave signal is subjected to waveform jump segment identification to obtain the elastic wave arrival time sequence; The arrival time difference characteristics between different acoustic emission sensors are extracted using the elastic wave arrival time sequence. Based on the arrival time difference characteristics, the propagation position of the thermal stress release source in the base transmission path is located and inverted to obtain the thermal stress release point. The spatial projection relationship of the thermal stress release points on the wafer support surface is mapped to obtain the thermal stress release point distribution.

[0008] In this embodiment, the confidence level of thermal imbalance at each measuring point is determined based on the consistency between the heat accumulation distribution and the distribution of thermal stress release points at the same measuring point. Measuring points with a thermal imbalance confidence level exceeding a preset threshold are specifically designated as local thermal imbalance regions. The heat accumulation intensity at each measuring point is extracted based on the heat accumulation distribution. The stress release proximity features of each measuring point are extracted based on the distribution of thermal stress release points. Based on the heat accumulation intensity and stress release proximity characteristics of each measuring point, the thermal imbalance consistency coefficient of each measuring point is obtained by performing a positional consistency matching of each measuring point. The thermal imbalance confidence level of each measuring point is determined by the thermal imbalance consistency coefficient of each measuring point, and the measuring points whose thermal imbalance confidence level exceeds the preset threshold are marked as local thermal imbalance areas.

[0009] In this embodiment, the thermal imbalance consistency coefficient of each measuring point is obtained by performing a co-location consistency matching based on the heat accumulation intensity and stress release proximity characteristics of each measuring point: Based on the heat accumulation intensity at each measuring point, the heat concentration measuring points on the wafer bearing surface are classified into thermal domains to obtain the thermal domain level of each measuring point. Based on the stress release proximity characteristics of each measuring point, the thermal stress proximity weight of each measuring point is assigned to the thermal domain level of each measuring point to obtain the thermal stress proximity weight of each measuring point. Based on the proximity weight of thermal stress at each measuring point, the heat accumulation intensity at each measuring point is corrected by in-situ coupling to obtain the thermal imbalance consistency coefficient of each measuring point.

[0010] In this embodiment, determining the reduction in injected heat flow of the heating unit based on the heat accumulation rate of the local thermal imbalance region specifically includes: The heat accumulation evolution characteristics are extracted based on the heat accumulation distribution in the local thermal imbalance region; By identifying the heat growth trend in the local thermal imbalance region based on the heat accumulation evolution characteristics, the heat accumulation growth factor is obtained. Based on the heat storage growth factor, the heat flow output margin of the associated heating unit in the local thermal imbalance region is matched with the reduction level to obtain the injected heat flow reduction level. The current injected heat flow of the heating unit is reduced by a step-down reduction level to obtain the amount of injected heat flow reduction.

[0011] In this embodiment, the heat growth trend of the local thermal imbalance region is identified by the heat accumulation evolution characteristics, and the heat accumulation growth factor specifically includes: Based on the heat accumulation evolution characteristics, the heat expansion boundary of the local thermal imbalance region at continuous sampling time is extracted; Based on the heat expansion boundary, the outward expansion trend of the heat accumulation range in the local thermal imbalance region is identified to obtain the outward expansion amount of heat accumulation. Based on the external expansion of the heat storage, the heat growth trend of the local thermal imbalance region is analyzed to obtain the heat storage growth factor.

[0012] In this embodiment, the injection heat flow reduction amount is gradient-modulated by the thermal stress release intensity of the local thermal imbalance region to obtain the target injection heat flow adapted for chip coating temperature uniformity control. Specifically, this includes: The thermal stress release intensity is extracted based on the density of thermal stress release points and the intensity of elastic wave signals within the local thermal imbalance area. By applying the thermal stress release intensity to the gradient constraint of the heat flow reduction demand in the local thermal imbalance region, a heat flow gradient modulation factor is obtained. The injected heat flux reduction amount is graded and adjusted according to the heat flux gradient modulation factor to obtain the gradient modulation reduction amount. By correcting the current injected heat flow of the heating unit through the gradient modulation reduction amount, a target injected heat flow suitable for chip coating temperature uniformity control is obtained.

[0013] In this embodiment, driving the heating unit with the target injected heat flow to reduce the heat accumulation rate and thermal stress release intensity of the local thermal imbalance region to within a corresponding threshold specifically includes: The heat flow driving quantity of the heating unit is generated by injecting heat flow into the target; The output heat flow of the heating unit is locally reduced according to the heat flow driving amount, so that the local thermal imbalance area enters the heat flow regulation state. Under the heat flow regulation state, the heat accumulation rate and thermal stress release intensity of the local thermal imbalance region are continuously acquired; When the heat accumulation rate and the heat stress release intensity decrease to within their respective thresholds, the heating unit maintains a stable output according to the target injected heat flow.

[0014] Secondly, this application provides a semiconductor thin film heating control system based on multi-sensor feedback, used to execute a semiconductor thin film heating control method based on multi-sensor feedback, the semiconductor thin film heating control system comprising: The multi-sensor synchronous acquisition module is used to acquire the tangential heat flux density of the film surface at each measurement point through the heat flux density sensor array on the wafer carrier surface, and synchronously acquire the elastic wave signal excited by thermal stress through the acoustic emission sensor coupled to the base. The thermal imbalance distribution positioning module is used to calculate the heat flux divergence of each measuring point based on the tangential heat flux density of the membrane surface of adjacent measuring points, obtain the heat storage distribution, and perform time difference of arrival positioning on the elastic wave signal to obtain the distribution of thermal stress release points. The thermal imbalance region calibration module is used to determine the thermal imbalance confidence level of each measuring point based on the consistency between the heat accumulation distribution and the distribution of the thermal stress release points at the same measuring point, and to calibrate the measuring points whose thermal imbalance confidence level exceeds a preset threshold as local thermal imbalance regions. The target heat flux modulation module is used to determine the amount of heat flux reduction of the heating unit based on the heat accumulation rate of the local thermal imbalance region, and to perform gradient modulation of the amount of heat flux reduction by the thermal stress release intensity of the local thermal imbalance region to obtain the target heat flux adapted to the chip coating temperature uniformity control. A heat flow driven module is used to drive the heating unit by injecting heat flow into the target, so that the heat accumulation rate and heat stress release intensity of the local thermal imbalance region are reduced to within the corresponding threshold.

[0015] The technical solutions provided by the embodiments disclosed in this application have the following beneficial effects: The tangential heat flux density of the film surface at each measuring point is acquired using a heat flux density sensor array on the wafer carrier surface, and the elastic wave signal excited by thermal stress is simultaneously acquired using an acoustic emission sensor coupled to the base. The heat flux divergence of each measuring point is calculated based on the tangential heat flux density of adjacent measuring points to obtain the heat accumulation distribution. The arrival time difference of the elastic wave signal is used to locate the distribution of thermal stress release points. The thermal imbalance confidence level of each measuring point is determined based on the consistency between the heat accumulation distribution and the thermal stress release point distribution at the same measuring point. Measuring points with thermal imbalance confidence levels exceeding a preset threshold are labeled as local thermal imbalance regions. The injected heat flux reduction amount of the heating unit is determined based on the heat accumulation rate of the local thermal imbalance region, and the injected heat flux reduction amount is gradient-modulated based on the thermal stress release intensity of the local thermal imbalance region to obtain the target injected heat flux adapted to the uniformity control of chip coating temperature. The heating unit is driven by the target injected heat flux to reduce the heat accumulation rate and thermal stress release intensity of the local thermal imbalance region to within the corresponding threshold.

[0016] Therefore, in this application, the heating unit can be driven by the target injected heat flow to reduce the heat accumulation rate and thermal stress release intensity of the local thermal imbalance region to within the corresponding threshold. Firstly, the tangential heat flux density of the film surface at each measuring point is acquired through a heat flux density sensor array, and the elastic wave signal excited by thermal stress is acquired simultaneously. This allows for the perception of local changes during the film heating process from two dimensions: heat transfer state and thermal stress release state, avoiding the lag in detecting local anomalies caused by relying solely on temperature measuring points. Secondly, the heat accumulation distribution is obtained through the heat flux adjacency relationship, tangential heat flux difference characteristics, and heat flux divergence characteristics of the measuring points. This reflects the spatial differences in heat convergence and diffusion on the wafer support surface, enabling timely capture of the heat concentration region forming inside the film. Furthermore, the distribution of thermal stress release points is obtained through the elastic wave arrival time sequence, arrival time difference characteristics, and location inversion. This allows for spatial correlation between the location of abnormal thermal stress release and the location of heat accumulation, providing a basis for determining whether a local thermal anomaly has occurred. This provides a basis for stress concentration. Furthermore, by matching the heat accumulation intensity and stress release proximity characteristics, a thermal imbalance consistency coefficient and thermal imbalance confidence level are obtained, which can improve the accuracy and reliability of identifying local thermal imbalance regions and reduce the risk of misjudgment and omission under a single temperature feedback method. At the same time, by identifying the heat accumulation growth factor through heat accumulation evolution characteristics and matching the injected heat flow reduction level and injected heat flow reduction amount accordingly, targeted heat flow reduction can be implemented according to the expansion trend of local thermal imbalance regions, avoiding insufficient or excessive adjustment caused by uniform power reduction. Finally, by gradient modulation of the injected heat flow reduction amount through thermal stress release intensity, the target injected heat flow is obtained and the heating unit is driven, so that the heat accumulation rate and thermal stress release intensity of local thermal imbalance regions are reduced to within the corresponding threshold. This can suppress the continuous expansion of local hot spots or low temperature regions, reduce the risk of thin film thermal stress concentration, crystal structure changes and film performance inconsistencies, thereby improving the uniformity of thin film temperature field distribution.

[0017] In summary, the technical solution adopted in this application can realize the dynamic identification of local thermal imbalance regions in semiconductor thin films, thereby improving the uniformity of the temperature field distribution of the thin film. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this embodiment of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is an exemplary flowchart of a semiconductor thin film heating control method based on multi-sensor feedback provided in this application; Figure 2 This is a schematic diagram of the semiconductor thin film heating control structure provided in this application; Figure 3 It is a comparison chart of the reduction ratio of membrane surface temperature and thermal imbalance index before and after regulation, based on the information provided in this application; Figure 4 This is a module structure diagram of a semiconductor thin film heating control system based on multi-sensor feedback provided in this application. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] This application provides a semiconductor thin film heating control method and system based on multi-sensor feedback. The core of this method involves acquiring the tangential heat flux density of the film surface at each measuring point using a heat flux density sensor array on the wafer support surface, and simultaneously acquiring the elastic wave signal excited by thermal stress using an acoustic emission sensor coupled to the base. The heat flux divergence at each measuring point is calculated based on the tangential heat flux density of adjacent measuring points to obtain the heat accumulation distribution. The arrival time difference of the elastic wave signal is then used to locate the thermal stress release point distribution. The heat accumulation distribution and the thermal stress release point distribution are then applied to the same measuring point. The consistency level at each measurement point determines the confidence level of thermal imbalance. Measurement points with a thermal imbalance confidence level exceeding a preset threshold are labeled as local thermal imbalance regions. The heat flow reduction amount of the heating unit is determined based on the heat accumulation rate of the local thermal imbalance region. The heat flow reduction amount is then gradient-modulated using the thermal stress release intensity of the local thermal imbalance region to obtain the target heat flow for controlling the uniformity of chip coating temperature. The heating unit is driven by the target heat flow to reduce the heat accumulation rate and thermal stress release intensity of the local thermal imbalance region to within the corresponding threshold.

[0022] Example 1: To better understand the above technical solution, the following will provide a detailed description of the technical solution in conjunction with the accompanying drawings and specific implementation methods. (Refer to...) Figure 1 As shown in the figure, this is an exemplary flowchart of a semiconductor thin film heating control method based on multi-sensor feedback according to this embodiment of the present application. The semiconductor thin film heating control method includes the following steps: In step S1, the tangential heat flux density of the film surface at each measuring point is obtained through the heat flux density sensor array on the wafer carrier surface, and the elastic wave signal excited by thermal stress is simultaneously obtained through the acoustic emission sensor coupled to the base.

[0023] It should be noted that the tangential heat flux density of the film surface mentioned in this application represents a physical quantity that reflects the strength of heat flow along the film surface at each measuring point on the wafer bearing surface; the elastic wave signal represents the mechanical vibration signal excited by the film when local stress is released under thermal stress and transmitted through the base.

[0024] In practice, multiple thin-film heat flux density sensors are embedded on the wafer carrier surface at a preset grid spacing to form a heat flux density sensor array. The sensitive surface of each sensor is flush with the wafer carrier surface and arranged tangentially along the film surface, so that its sensing direction is aligned with the line connecting adjacent measurement points. Each sensor outputs a real-time analog signal of the heat flux density along the film surface at its measurement point. This signal is converted into a digital quantity by a data acquisition card at a preset sampling frequency. The digital quantity output by each sensor is used as the tangential heat flux density of the film surface at each measurement point. At the same time, multiple piezoelectric acoustic emission sensors are attached to the lower surface of the wafer substrate with a coupling agent to form an acoustic coupling between the acoustic emission sensors and the substrate. When microcracks or dislocation slips occur inside the thin film due to thermal stress concentration and release elastic waves, the elastic waves are transmitted to each acoustic emission sensor through the substrate. Each acoustic emission sensor converts the vibration into an electrical signal and is synchronously triggered for acquisition by the same acquisition clock shared with the heat flux density sensor array. The electrical signals synchronously output by each acoustic emission sensor are used as the elastic wave signals excited by thermal stress.

[0025] It should also be noted that the reference Figure 2 As shown, Figure 2 This is a schematic diagram of the semiconductor thin film heating control structure provided in this application. In the figure, 1 is the processing cavity, which provides the working environment for chip coating heating control; 2 is the wafer support surface, which supports the wafer to be coated and serves as the area for obtaining the tangential heat flux density of the film surface; 3 is the support platform, which supports the wafer support surface and connects to the lower execution structure; 4 is the heat flux density sensor array, which obtains the tangential heat flux density of the film surface at each measuring point; 5 is the heating unit, which adjusts the heat flux of a local area according to the target injected heat flux; 6 is the base, which installs and supports each heating unit and detection component; 7 is the acoustic emission sensor, which synchronously obtains the elastic wave signal excited by thermal stress; 8 is the controller, which receives the heat flux signal and the elastic wave signal, and completes the calculation and control of heat accumulation distribution, thermal stress release point distribution, thermal imbalance confidence level, and target injected heat flux; 9 is the local thermal imbalance region, which represents the region to be controlled where heat accumulation and thermal stress release are relatively concentrated.

[0026] In step S2, the heat flux divergence of each measuring point is calculated based on the tangential heat flux density of the membrane surface of adjacent measuring points to obtain the heat storage distribution, and the arrival time difference of the elastic wave signal is used to locate the distribution of thermal stress release points.

[0027] In this embodiment, the heat flux divergence of each measuring point is calculated based on the tangential heat flux density of adjacent measuring points, and the heat storage distribution is obtained by the following steps: The heat flux adjacency relationship of the measuring points is established based on the arrangement of each measuring point in the heat flux density sensor array on the wafer carrier surface; Based on the heat flux adjacency relationship of the measuring points, the directional difference of the tangential heat flux density on the membrane surface of adjacent measuring points is extracted to obtain the tangential heat flux difference characteristics; By extracting the divergence features of the heat flow convergence degree at each measuring point through the tangential heat flow difference characteristics, the heat flow divergence features of each measuring point are obtained. Based on the heat flux divergence characteristics of each measuring point, the heat concentration area of ​​the wafer bearing surface is distributed and mapped to obtain the heat storage distribution.

[0028] It should be noted that the heat flow adjacency relationship of the measuring points mentioned in this application represents the correspondence between adjacent measuring points on the wafer carrier surface; the tangential heat flow difference characteristic represents the characteristic of the difference in the tangential heat flow density direction between adjacent measuring points; the heat flow divergence characteristic represents the characteristic of the degree of heat flow convergence at each measuring point; and the heat storage distribution represents the spatial distribution of the heat concentration area on the wafer carrier surface.

[0029] In specific implementation, firstly, the row and column coordinates of each measuring point in the heat flux density sensor array on the wafer carrier surface are read. Euclidean distance comparisons are performed on each measuring point according to a preset adjacency radius. Measuring points whose distances fall within the adjacency radius are marked as adjacent measuring points. An adjacency table is established using the measuring point number as an index to record the correspondence between each measuring point and its adjacent measuring points. This adjacency table serves as the heat flux adjacency relationship between measuring points. Secondly, based on the heat flux adjacency relationship, the tangential heat flux density of each measuring point and its adjacent measuring points is retrieved one by one. A vector subtraction operation is performed along the direction connecting the two measuring points to obtain the difference in tangential heat flux density in the direction from the measuring point to each adjacent measuring point. The difference groups formed by aggregating the heat flux density differences in each direction are used as tangential heat flux difference characteristics. Then, a method is used... The differential dispersion operator operates on the tangential heat flux difference characteristics, dividing the heat flux density difference between each measuring point in two mutually orthogonal directions by the distance between the measuring points in the corresponding directions and summing the results to obtain the net outflow rate of the film surface heat flux at that measuring point. The net outflow rate is used as the heat flux divergence characteristic of each measuring point. Finally, the heat flux divergence characteristics of each measuring point are backfilled into a two-dimensional grid corresponding to the wafer bearing surface according to their arrangement coordinates on the wafer bearing surface. The bilinear interpolation method is used to interpolate and fill in the missing positions between each measuring point in the grid to obtain a continuous divergence field covering the entire wafer bearing surface. Then, the grid regions in the continuous divergence field with negative divergence characteristics and absolute values ​​exceeding the preset convergence threshold are delineated. The delineated grid regions reflecting the spatial distribution of heat concentration areas are used as the heat storage distribution.

[0030] In this embodiment, the distribution of thermal stress release points by determining the time difference of arrival of the elastic wave signal can be achieved through the following steps: The elastic wave signal is subjected to waveform jump segment identification to obtain the elastic wave arrival time sequence; The arrival time difference characteristics between different acoustic emission sensors are extracted using the elastic wave arrival time sequence. Based on the arrival time difference characteristics, the propagation position of the thermal stress release source in the base transmission path is located and inverted to obtain the thermal stress release point. The spatial projection relationship of the thermal stress release points on the wafer support surface is mapped to obtain the thermal stress release point distribution.

[0031] It should be noted that the elastic wave arrival time sequence mentioned in this application represents the sequence formed by the start times of each acoustic emission sensor receiving the elastic wave signal; the arrival time difference feature represents the feature reflecting the time difference of the same elastic wave arriving at different acoustic emission sensors; the thermal stress release point represents the position of the thermal stress release source in the base transmission path; and the thermal stress release point distribution represents the spatial distribution of thermal stress release points on the wafer bearing surface.

[0032] In specific implementation, firstly, the Akaike information content criterion-based jump point detection method is used to calculate the Akaike information content segment by segment of the elastic wave signal output by each acoustic emission sensor. The sampling time corresponding to the point where the Akaike information content reaches its minimum value is determined as the jump time of that elastic wave signal. The sequence formed by aggregating the jump times of each acoustic emission sensor according to the sensor number is used as the elastic wave arrival time sequence. Secondly, from the elastic wave arrival time sequence, the acoustic emission sensor that first receives the elastic wave signal is used as the reference sensor. The jump times of the remaining acoustic emission sensors are subtracted from the jump time of the reference sensor to obtain the arrival time difference value of each acoustic emission sensor relative to the reference sensor. The arrival time difference value corresponding to each acoustic emission sensor is used as the arrival time difference feature. Then, the sampling... Using the hyperbolic positioning method based on the propagation speed of elastic waves in the base, the installation coordinates of each acoustic emission sensor on the base and the propagation speed of elastic waves in the base material are substituted into the equations for the positioning method based on the time difference of arrival. The trajectory of the isochronous point corresponding to each time difference of arrival characteristic is constructed as a hyperbola with the positions of the two sensors as the focus. The intersection points of each hyperbola are used to inversely determine the position of the elastic wave emission, and the intersection points are taken as the thermal stress release points. Finally, according to the pre-defined geometric correspondence between the wafer support surface and the base, the thermal stress release points are projected along the base normal to the plane where the wafer support surface is located, and the projected coordinates of each thermal stress release point on the wafer support surface are obtained. The spatial distribution of the projected coordinates on the wafer support surface is taken as the thermal stress release point distribution.

[0033] In step S3, the thermal imbalance confidence level of each measuring point is determined based on the consistency between the heat storage distribution and the thermal stress release point distribution at the same measuring point. Measuring points with thermal imbalance confidence levels exceeding a preset threshold are labeled as local thermal imbalance areas.

[0034] In this embodiment, the confidence level of thermal imbalance at each measuring point is determined based on the consistency between the heat accumulation distribution and the distribution of thermal stress release points at the same measuring point. Measuring points with a thermal imbalance confidence level exceeding a preset threshold are designated as localized thermal imbalance regions. This can be achieved through the following steps: The heat accumulation intensity at each measuring point is extracted based on the heat accumulation distribution. The stress release proximity features of each measuring point are extracted based on the distribution of thermal stress release points. Based on the heat accumulation intensity and stress release proximity characteristics of each measuring point, the thermal imbalance consistency coefficient of each measuring point is obtained by performing a positional consistency matching of each measuring point. The thermal imbalance confidence level of each measuring point is determined by the thermal imbalance consistency coefficient of each measuring point, and the measuring points whose thermal imbalance confidence level exceeds the preset threshold are marked as local thermal imbalance areas.

[0035] It should be noted that, in this application, the heat accumulation intensity refers to the strength of the heat concentration at the measuring point; the stress release proximity characteristic refers to the density of thermal stress release points near the measuring point; the thermal imbalance confidence level refers to the degree of confidence that the measuring point belongs to a thermal imbalance state; and the local thermal imbalance region refers to an imbalance region on the wafer bearing surface where heat concentration and thermal stress release coexist.

[0036] In specific implementation, firstly, based on the arrangement coordinates of each measuring point on the wafer support surface, the absolute value of the negative divergence at each measuring point's location is read from the heat accumulation distribution, and this absolute value is taken as the heat accumulation intensity of each measuring point. Secondly, a statistical neighborhood is defined with the position of each measuring point on the wafer support surface as the center and a preset statistical radius. The number of heat stress release points falling into the statistical neighborhood of each measuring point is counted from the distribution of heat stress release points, and this number of release points is taken as the stress release proximity characteristic of each measuring point. Next, based on the heat accumulation intensity and stress release proximity characteristic of each measuring point, a co-location consistency matching is performed on each measuring point to obtain the thermal imbalance consistency coefficient of each measuring point. Finally, the thermal imbalance confidence level of each measuring point is calculated using the following formula: ,in, Indicates the first Confidence level of thermal imbalance at each measuring point; Indicates the first Consistency coefficient of thermal imbalance at each measuring point; Indicates the first Consistency coefficient of thermal imbalance at each measuring point; This represents the set of all measurement points on the wafer bearing surface that participate in the calculation of the confidence level of thermal imbalance. Indicates the first The heat accumulation intensity at each measuring point; Indicates the first The heat accumulation intensity at each measuring point; The confidence enhancement coefficient represents the coefficient of consistency of heat accumulation intensity with thermal imbalance, and the confidence enhancement coefficient can be preset according to the degree of local heat accumulation allowed by the chip coating process; This indicates the use of extremely small positive numbers to prevent the denominator from being zero; then, the obtained thermal imbalance confidence scores are compared one by one with the preset threshold, and the area occupied by the measurement points whose thermal imbalance confidence scores exceed the preset threshold on the wafer bearing surface is marked as a local thermal imbalance region.

[0037] In this embodiment, the thermal imbalance consistency coefficient of each measuring point is obtained by performing co-location consistency matching based on the heat accumulation intensity and stress release proximity characteristics of each measuring point, using the following steps: Based on the heat accumulation intensity at each measuring point, the heat concentration measuring points on the wafer bearing surface are classified into thermal domains to obtain the thermal domain level of each measuring point. By assigning proximity weights to the thermal stress proximity weights of each measuring point based on the stress release proximity characteristics of each measuring point, the thermal stress proximity weights of each measuring point are obtained. Based on the proximity weight of thermal stress at each measuring point, the heat accumulation intensity at each measuring point is corrected by in-situ coupling to obtain the thermal imbalance consistency coefficient of each measuring point.

[0038] It should be noted that, in this application, the thermal domain classification refers to the process of classifying each measuring point according to the degree of heat concentration; the thermal domain level refers to the level reflecting the degree of heat concentration at each measuring point; the thermal stress proximity weight refers to the weight reflecting the magnitude of the influence of thermal stress release on heat accumulation at each measuring point; the co-location coupling correction refers to the correction process that couples the influence of thermal stress release with the intensity of heat accumulation at the same measuring point; and the thermal imbalance consistency coefficient refers to the coefficient reflecting the degree to which heat accumulation and thermal stress release occur simultaneously at the same location at each measuring point.

[0039] In specific implementation, firstly, the range of heat accumulation intensity from 0 to the maximum value of the entire field at each measuring point is divided into several intervals using the equidistant grading method. Each measuring point is assigned a corresponding grade number from low to high according to the interval into which its heat accumulation intensity falls, and this grade number serves as the thermal domain level of each measuring point. Secondly, the stress release proximity characteristics of each measuring point are normalized to a coefficient between 0 and 1 using the maximum value of the entire field using the linear mapping method. This coefficient is then multiplied by the thermal domain level of each measuring point, and the resulting product serves as the thermal stress proximity weight for each measuring point. Finally, the thermal stress proximity weight of each measuring point is multiplied point-by-point by the heat accumulation intensity of each measuring point to complete the in-situ coupling correction, and the resulting product serves as the thermal imbalance consistency coefficient for each measuring point.

[0040] In step S4, the amount of heat flow reduction of the heating unit is determined according to the heat accumulation rate of the local thermal imbalance region, and the amount of heat flow reduction is gradient-modulated by the thermal stress release intensity of the local thermal imbalance region to obtain the target heat flow for the uniformity control of chip coating temperature.

[0041] In this embodiment, determining the reduction in injected heat flow of the heating unit based on the heat accumulation rate of the local thermal imbalance region can be achieved through the following steps: The heat accumulation evolution characteristics are extracted based on the heat accumulation distribution in the local thermal imbalance region; By identifying the heat growth trend in the local thermal imbalance region based on the heat accumulation evolution characteristics, the heat accumulation growth factor is obtained. Based on the heat storage growth factor, the heat flow output margin of the associated heating unit in the local thermal imbalance region is matched with the reduction level to obtain the injected heat flow reduction level. The current injected heat flow of the heating unit is reduced by a step-down reduction level to obtain the amount of injected heat flow reduction.

[0042] It should be noted that the heat accumulation evolution characteristics described in this application represent the characteristics of how quickly the heat accumulation in a local thermal imbalance area changes over time; the reduction level matching represents the process of matching the heating unit with a corresponding reduction level according to the strength of heat growth; the heating unit represents an actuator used to inject heat flow into the wafer carrier surface to heat the chip coating; the injected heat flow reduction level represents the level reflecting the reduction level of the injected heat flow of the heating unit; the step reduction represents the process of gradually reducing the current injected heat flow according to the reduction level; and the injected heat flow reduction amount represents the amount of heat flow that the current injected heat flow of the heating unit should be reduced.

[0043] In specific implementation, firstly, the absolute values ​​of negative divergence in the heat accumulation distribution of each measuring point within the local thermal imbalance area are continuously read according to a preset sampling period. The difference between the sum of these absolute values ​​in the same area within two adjacent sampling periods is divided by the sampling period duration to obtain the rate of change of heat accumulation per unit time in the local thermal imbalance area. This rate of change is used as the heat accumulation evolution characteristic. Secondly, the heat growth trend in the local thermal imbalance area is identified using the heat accumulation evolution characteristic to obtain the heat accumulation growth factor. Then, the range of values ​​for the heat accumulation growth factor is pre-divided into several levels from low to high using an interval mapping method, and each level is set as follows: A reduction level is assigned from low to high (e.g., divided into three levels, with the level set based on balancing reduction precision and control stability). The corresponding reduction level is read according to the level into which the current heat accumulation growth factor of the heating unit falls in the local thermal imbalance region, and this reduction level is used as the injection heat flow reduction level. Finally, a step-down reduction coefficient between 0 and 1 is pre-configured for each injection heat flow reduction level, with the step-down reduction coefficient being larger for higher reduction levels. The corresponding step-down reduction coefficient is read according to the injection heat flow reduction level, and this step-down reduction coefficient is multiplied by the current injection heat flow of the heating unit. The resulting product is used as the injection heat flow reduction amount.

[0044] In this embodiment, the heat accumulation growth factor is identified by analyzing the heat growth trend in the local thermal imbalance region based on the heat accumulation evolution characteristics. This can be achieved through the following steps: Based on the heat accumulation evolution characteristics, the heat expansion boundary of the local thermal imbalance region at continuous sampling time is extracted; Based on the heat expansion boundary, the outward expansion trend of the heat accumulation range in the local thermal imbalance region is identified to obtain the outward expansion amount of heat accumulation. Based on the external expansion of the heat storage, the heat growth trend of the local thermal imbalance region is analyzed to obtain the heat storage growth factor.

[0045] It should be noted that, in this application, the growth factor identification refers to the process of identifying the strength of growth from the time change of heat accumulation; the heat expansion boundary refers to the outer contour of the heat accumulation range of the local thermal imbalance region at each sampling time; the outward expansion trend identification refers to the process of identifying the outward expansion of the heat accumulation range from the change of the heat expansion boundary over time; the heat accumulation outward expansion amount refers to a parameter reflecting the size of the outward expansion of the heat accumulation range in the local thermal imbalance region; the outward expansion amount analysis refers to the process of inferring the strength of heat growth from the size of the outward expansion of the heat accumulation range; and the heat accumulation growth factor refers to a factor reflecting the strength of heat growth in the local thermal imbalance region.

[0046] In practice, firstly, the grid regions with negative divergence in the local thermal imbalance region are read one by one at each sampling time according to the preset sampling period. The boundary tracking method is used to connect the outermost grids of the grid region at each sampling time, and the closed outer edge contour formed is taken as the heat expansion boundary of the local thermal imbalance region at that sampling time. Secondly, the grid counting method is used to count the number of grids enclosed by the heat expansion boundary at two adjacent sampling times. The difference between the number of enclosed grids at the later sampling time and the number of enclosed grids at the previous sampling time is taken as the heat accumulation expansion amount. Finally, the heat accumulation expansion amount is divided by the time interval between two adjacent sampling times to obtain the expansion rate of the heat accumulation range per unit time, and this expansion rate is taken as the heat accumulation growth factor.

[0047] In this embodiment, the target injected heat flow reduction amount is obtained by gradient modulation of the thermal stress release intensity in the local thermal imbalance region to adapt to the chip coating temperature uniformity control. This can be achieved through the following steps: The thermal stress release intensity is extracted based on the density of thermal stress release points and the intensity of elastic wave signals within the local thermal imbalance area. By applying the thermal stress release intensity to the gradient constraint of the heat flow reduction demand in the local thermal imbalance region, a heat flow gradient modulation factor is obtained. The injected heat flux reduction amount is graded and adjusted according to the heat flux gradient modulation factor to obtain the gradient modulation reduction amount. By correcting the current injected heat flow of the heating unit through the gradient modulation reduction amount, a target injected heat flow suitable for chip coating temperature uniformity control is obtained.

[0048] It should be noted that, in this application, the thermal stress release intensity refers to the severity of thermal stress release within a local thermal imbalance region; the heat flow reduction requirement refers to the amount of injected heat flow that needs to be reduced within the local thermal imbalance region; the gradient constraint refers to the process of applying a gradient limit to the heat flow reduction amplitude according to the severity of thermal stress release; the heat flow gradient modulation factor refers to a parameter reflecting the magnitude of the gradient modulation of the injected heat flow reduction amount; the graded modulation refers to the process of adjusting the injected heat flow reduction amount in stages according to the modulation amplitude; the gradient modulation reduction amount refers to the heat flow that the current injected heat flow of the heating unit should reduce after gradient modulation; and the target injected heat flow refers to the injected heat flow of the heating unit adapted to the uniformity control of chip coating temperature.

[0049] In specific implementation, firstly, the number of thermal stress release points within the local thermal imbalance region is counted using a grid counting method and divided by the grid area occupied by that region to obtain the distribution density of thermal stress release points in that region. Simultaneously, the amplitude of the elastic wave signal corresponding to each thermal stress release point in that region is averaged to obtain the elastic wave signal intensity of that region. Then, the distribution density and the elastic wave signal intensity are normalized to their respective maximum values ​​across the entire field and multiplied together, and the resulting product is taken as the thermal stress release intensity. Secondly, the thermal stress release intensity is normalized to a coefficient between 0 and 1 using a linear mapping method, and then 1 is subtracted from this coefficient to obtain the reduction ratio for applying a gradient limit to the heat flux reduction amplitude. This reduction ratio is taken as the heat flux gradient modulation factor. Next, the heat flux gradient modulation factor is multiplied by the injected heat flux reduction amount to reduce the injected heat flux reduction amount in stages, and the resulting product is taken as the gradient modulation reduction amount. Finally, the target injected heat flux for adapting chip coating temperature uniformity control is calculated using the following formula: ,in, Indicates the first The target injected heat flow is associated with the heating unit in the local thermal imbalance region; Indicates the first The current injected heat flow of the heating unit is associated with each local thermal imbalance region; Indicates according to the first The amount of heat flow reduction determined by the heat accumulation rate of a local thermal imbalance region; Indicates the first The intensity of thermal stress release in a localized thermal imbalance region; The modulation factor represents the reduction in injected heat flow as a function of thermal stress release intensity. The modulation factor can be preset according to the range of stress release intensity allowed by the chip coating process. Indicates the first The heat flux gradient modulation factor corresponding to a local thermal imbalance region.

[0050] In step S5, the heating unit is driven by the target injected heat flow to reduce the heat accumulation rate and thermal stress release intensity of the local thermal imbalance region to within the corresponding threshold.

[0051] In this embodiment, the following steps can be used to reduce the heat accumulation rate and thermal stress release intensity in the local thermal imbalance region to within the corresponding threshold by driving the heating unit with the target injected heat flow: The heat flow driving quantity of the heating unit is generated by injecting heat flow into the target; The output heat flow of the heating unit is locally reduced according to the heat flow driving amount, so that the local thermal imbalance area enters the heat flow regulation state. Under the heat flow regulation state, the heat accumulation rate and thermal stress release intensity of the local thermal imbalance region are continuously acquired; When the heat accumulation rate and the heat stress release intensity decrease to within their respective thresholds, the heating unit maintains a stable output according to the target injected heat flow.

[0052] It should be noted that, in this application, the heat flow driving amount refers to the driving amount of the target injected heat flow that drives the heating unit to output; the local reduction driving refers to the driving process of locally reducing the output heat flow of the heating unit according to the heat flow driving amount; the heat flow regulation state refers to the state in which the output heat flow of the local thermal imbalance area is under controlled reduction; the heat accumulation rate refers to the rate at which the heat accumulation in the local thermal imbalance area changes with time; and the thermal stress release intensity refers to the degree of intensity of thermal stress release in the local thermal imbalance area.

[0053] In specific implementation, firstly, a lookup table is used to pre-establish the correspondence between the injected heat flow value of the heating unit and its driving control quantity. The corresponding driving control quantity is retrieved according to the target injected heat flow, and this driving control quantity is used as the heat flow driving quantity of the heating unit. Secondly, the heat flow driving quantity is sent to the heating unit associated with the local thermal imbalance area via the driving circuit. This heating unit then adjusts its output heat flow from its current value to the value corresponding to the target injected heat flow according to the heat flow driving quantity, completing the local reduction drive and placing the output heat flow of the local thermal imbalance area in a controlled reduction heat flow regulation state. Then, under the heat flow regulation state, the heat flow is continuously acquired... The heat accumulation rate and thermal stress release intensity of the local thermal imbalance region are measured. Finally, the continuously extracted heat accumulation rate and thermal stress release intensity are compared with their respective preset thresholds (wherein, the heat accumulation rate threshold can be set as the maximum heat accumulation change rate allowed by the chip coating process, and the thermal stress release intensity threshold can be set as the maximum release intensity that will not cause stress damage to the thin film) cycle by cycle. When both the heat accumulation rate and thermal stress release intensity decrease to within their respective thresholds, the further reduction of the output heat flow of the heating unit is stopped, and the stable output of the heating unit is maintained according to the heat flow drive amount corresponding to the target injected heat flow.

[0054] For example, five sets of wafer carrier surface heating samples can be selected within the same chip coating process window, and the film surface temperature difference, heat accumulation rate, thermal stress release intensity, and film thickness relative deviation can be recorded before and after the heating unit enters stable output. The above four types of data correspond to the temperature uniformity result, the degree of heat concentration, the degree of local thermal stress release, and the film formation consistency result in this application, respectively. The control effect of the target injected heat flow can be verified from four perspectives: heat input distribution, heat accumulation change, stress release change, and coating result. Specifically, the temperature ranges of the membrane surfaces of the first five groups of samples before adjustment were 8.7℃, 8.3℃, 9.1℃, 8.5℃, and 8.9℃, respectively, which decreased to 3.4℃, 3.1℃, 3.6℃, ​​3.2℃, and 3.5℃ after adjustment. The normalized heat accumulation rates of the first five groups of samples before adjustment were 0.86, 0.81, 0.90, 0.84, and 0.88, respectively, which decreased to 0.31, 0.29, 0.34, 0.30, and 0.3 after adjustment. 2; The normalized thermal stress release intensities of the first five groups of samples were 0.72, 0.69, 0.76, 0.70 and 0.74, respectively, and decreased to 0.28, 0.25, 0.30, 0.27 and 0.29 after adjustment; The relative deviations of film thickness of the first five groups of samples were 3.8%, 3.5%, 4.1%, 3.7% and 3.9%, respectively, and decreased to 1.6%, 1.4%, 1.7%, 1.5% and 1.6% after adjustment. Based on the recorded data, calculations show that after enabling target injection heat flow control, the average temperature range of the film surface decreased from 8.70℃ to 3.36℃, a reduction of 61.4%; the average normalized heat accumulation rate decreased from 0.858 to 0.312, a reduction of 63.6%; the average normalized thermal stress release intensity decreased from 0.722 to 0.278, a reduction of 61.5%; and the average relative deviation of film thickness decreased from 3.80% to 1.56%, a reduction of 58.9%. (Reference) Figure 3 As shown in the figure, this is a comparison of the reduction ratios of film surface temperature and thermal imbalance indicators before and after the adjustment provided in this application. In this figure, the reduction ratios of film surface temperature range, heat accumulation rate, and thermal stress release intensity all exceed 60%, and the reduction ratio of relative deviation of film thickness is close to 60%. This indicates that the target injected heat flow control does not only change a single temperature indicator, but also simultaneously suppresses the continued concentration of local heat and the continuous release of thermal stress. It can be seen that after the heat flow driving amount causes the associated heating unit to enter local reduction driving, the trend of continued heat accumulation in the local thermal imbalance area and the intensity of thermal stress release decrease simultaneously, and the film surface temperature range and relative deviation of film thickness decrease accordingly. This shows that this application can improve the reliability and film uniformity of the chip coating temperature control process by jointly calibrating the local thermal imbalance area by heat accumulation distribution and thermal stress release point distribution, and then gradient-modulating the injected heat flow reduction amount.

[0055] Therefore, in this application, the heating unit can be driven by the target injected heat flow to reduce the heat accumulation rate and thermal stress release intensity of the local thermal imbalance region to within the corresponding threshold. Firstly, the tangential heat flux density of the film surface at each measuring point is acquired through a heat flux density sensor array, and the elastic wave signal excited by thermal stress is acquired simultaneously. This allows for the perception of local changes during the film heating process from two dimensions: heat transfer state and thermal stress release state, avoiding the lag in detecting local anomalies caused by relying solely on temperature measuring points. Secondly, the heat accumulation distribution is obtained through the heat flux adjacency relationship, tangential heat flux difference characteristics, and heat flux divergence characteristics of the measuring points. This reflects the spatial differences in heat convergence and diffusion on the wafer support surface, enabling timely capture of the heat concentration region forming inside the film. Furthermore, the distribution of thermal stress release points is obtained through the elastic wave arrival time sequence, arrival time difference characteristics, and location inversion. This allows for spatial correlation between the location of abnormal thermal stress release and the location of heat accumulation, providing a basis for determining whether a local thermal anomaly has occurred. This provides a basis for stress concentration. Furthermore, by matching the heat accumulation intensity and stress release proximity characteristics, a thermal imbalance consistency coefficient and thermal imbalance confidence level are obtained, which can improve the accuracy and reliability of identifying local thermal imbalance regions and reduce the risk of misjudgment and omission under a single temperature feedback method. At the same time, by identifying the heat accumulation growth factor through heat accumulation evolution characteristics and matching the injected heat flow reduction level and injected heat flow reduction amount accordingly, targeted heat flow reduction can be implemented according to the expansion trend of local thermal imbalance regions, avoiding insufficient or excessive adjustment caused by uniform power reduction. Finally, by gradient modulation of the injected heat flow reduction amount through thermal stress release intensity, the target injected heat flow is obtained and the heating unit is driven, so that the heat accumulation rate and thermal stress release intensity of local thermal imbalance regions are reduced to within the corresponding threshold. This can suppress the continuous expansion of local hot spots or low temperature regions, reduce the risk of thin film thermal stress concentration, crystal structure changes and film performance inconsistencies, thereby improving the uniformity of thin film temperature field distribution.

[0056] In summary, the technical solution adopted in this application can realize the dynamic identification of local thermal imbalance regions in semiconductor thin films, thereby improving the uniformity of the temperature field distribution of the thin film.

[0057] Example 2: This application provides a semiconductor thin film heating control system based on multi-sensor feedback, referencing... Figure 4 As shown in the figure, this is a module structure diagram of a semiconductor thin film heating control system based on multi-sensor feedback according to this embodiment of the present application. The semiconductor thin film heating control system includes: The multi-sensor synchronous acquisition module 100 is used to acquire the tangential heat flux density of the film surface at each measuring point through the heat flux density sensor array on the wafer carrier surface, and synchronously acquire the elastic wave signal excited by thermal stress through the acoustic emission sensor coupled to the base. The thermal imbalance distribution positioning module 200 is used to calculate the heat flux divergence of each measuring point based on the tangential heat flux density of the membrane surface of adjacent measuring points, obtain the heat storage distribution, and perform time difference of arrival positioning on the elastic wave signal to obtain the distribution of thermal stress release points. The thermal imbalance region calibration module 300 is used to determine the thermal imbalance confidence level of each measuring point based on the consistency between the heat storage distribution and the distribution of the thermal stress release points at the same measuring point, and to calibrate the measuring points whose thermal imbalance confidence level exceeds a preset threshold as local thermal imbalance regions. The target heat flux modulation module 400 is used to determine the amount of heat flux reduction of the heating unit based on the heat accumulation rate of the local thermal imbalance region, and to perform gradient modulation of the amount of heat flux reduction by the thermal stress release intensity of the local thermal imbalance region to obtain the target heat flux adapted to the chip coating temperature uniformity control. The heat flow drive module 500 is used to drive the heating unit through the target heat flow injection, so that the heat accumulation rate and heat stress release intensity of the local thermal imbalance region are reduced to within the corresponding threshold.

[0058] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0059] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, including read-only memory (ROM), random access memory (RAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), one-time programmable read-only memory (OTPROM), electrically-Erasable Programmable Read-Only Memory (EEPROM), compactdisc read-only memory (CD-ROM) or other optical disc storage, disk storage, magnetic tape storage, or any other computer-readable medium capable of carrying or storing data.

[0060] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

Claims

1. A semiconductor thin film heating control method based on multi-sensor feedback, applied to the chip coating temperature control process, characterized in that, Includes the following steps: The tangential heat flux density of the film surface at each measuring point is obtained by a heat flux density sensor array on the wafer carrier surface, and the elastic wave signal excited by thermal stress is simultaneously obtained by an acoustic emission sensor coupled to the base. The heat flux divergence of each measuring point is calculated based on the tangential heat flux density of the membrane surface of adjacent measuring points to obtain the heat storage distribution. The arrival time difference of the elastic wave signal is used to locate the distribution of thermal stress release points. The thermal imbalance confidence level of each measuring point is determined based on the consistency between the heat storage distribution and the thermal stress release point distribution at the same measuring point. Measuring points with thermal imbalance confidence levels exceeding a preset threshold are labeled as local thermal imbalance areas. The amount of heat flow reduction of the heating unit is determined based on the heat accumulation rate of the local thermal imbalance region, and the amount of heat flow reduction is gradient-modulated by the thermal stress release intensity of the local thermal imbalance region to obtain the target heat flow that is adapted to the uniformity control of chip coating temperature. The heating unit is driven by the target injected heat flow, so that the heat accumulation rate and thermal stress release intensity of the local thermal imbalance region are reduced to within the corresponding threshold.

2. The semiconductor thin film heating control method based on multi-sensor feedback as described in claim 1, characterized in that, The heat dissipation at each measuring point is calculated based on the tangential heat flux density of the membrane surface at adjacent measuring points, resulting in the heat storage distribution, specifically including: The heat flux adjacency relationship of the measuring points is established based on the arrangement of each measuring point in the heat flux density sensor array on the wafer carrier surface; Based on the heat flux adjacency relationship of the measuring points, the directional difference of the tangential heat flux density on the membrane surface of adjacent measuring points is extracted to obtain the tangential heat flux difference characteristics; By extracting the divergence features of the heat flow convergence degree at each measuring point through the tangential heat flow difference characteristics, the heat flow divergence features of each measuring point are obtained. Based on the heat flux divergence characteristics of each measuring point, the heat concentration area of ​​the wafer bearing surface is distributed and mapped to obtain the heat storage distribution.

3. The semiconductor thin film heating control method based on multi-sensor feedback as described in claim 1, characterized in that, The specific steps for determining the distribution of thermal stress release points by performing time difference of arrival (TDOA) positioning on the elastic wave signal include: The elastic wave signal is subjected to waveform jump segment identification to obtain the elastic wave arrival time sequence; The arrival time difference characteristics between different acoustic emission sensors are extracted using the elastic wave arrival time sequence. Based on the arrival time difference characteristics, the propagation position of the thermal stress release source in the base transmission path is located and inverted to obtain the thermal stress release point. The spatial projection relationship of the thermal stress release points on the wafer support surface is mapped to obtain the thermal stress release point distribution.

4. The semiconductor thin film heating control method based on multi-sensor feedback as described in claim 1, characterized in that, The confidence level of thermal imbalance at each measuring point is determined based on the consistency between the heat storage distribution and the distribution of thermal stress release points at the same measuring point. Measuring points with a thermal imbalance confidence level exceeding a preset threshold are specifically designated as local thermal imbalance regions, including: The heat accumulation intensity at each measuring point is extracted based on the heat accumulation distribution. The stress release proximity features of each measuring point are extracted based on the distribution of thermal stress release points. Based on the heat accumulation intensity and stress release proximity characteristics of each measuring point, the thermal imbalance consistency coefficient of each measuring point is obtained by performing a positional consistency matching of each measuring point. The thermal imbalance confidence level of each measuring point is determined by the thermal imbalance consistency coefficient of each measuring point, and the measuring points whose thermal imbalance confidence level exceeds the preset threshold are marked as local thermal imbalance areas.

5. The semiconductor thin film heating control method based on multi-sensor feedback as described in claim 4, characterized in that, Based on the heat accumulation intensity and stress release proximity characteristics of each measuring point, a co-location consistency matching was performed on each measuring point to obtain the thermal imbalance consistency coefficient of each measuring point, which specifically includes: Based on the heat accumulation intensity at each measuring point, the heat concentration measuring points on the wafer bearing surface are classified into thermal domains to obtain the thermal domain level of each measuring point. Based on the stress release proximity characteristics of each measuring point, the thermal stress proximity weight of each measuring point is assigned to the thermal domain level of each measuring point to obtain the thermal stress proximity weight of each measuring point. Based on the proximity weight of thermal stress at each measuring point, the heat accumulation intensity at each measuring point is corrected by in-situ coupling to obtain the thermal imbalance consistency coefficient of each measuring point.

6. The semiconductor thin film heating control method based on multi-sensor feedback as described in claim 1, characterized in that, The specific methods for determining the reduction in injected heat flow of the heating unit based on the heat accumulation rate in the local thermal imbalance region include: The heat accumulation evolution characteristics are extracted based on the heat accumulation distribution in the local thermal imbalance region; By identifying the heat growth trend in the local thermal imbalance region based on the heat accumulation evolution characteristics, the heat accumulation growth factor is obtained. Based on the heat storage growth factor, the heat flow output margin of the associated heating unit in the local thermal imbalance region is matched with the reduction level to obtain the injected heat flow reduction level. The current injected heat flow of the heating unit is reduced by a step-down reduction level to obtain the amount of injected heat flow reduction.

7. The semiconductor thin film heating control method based on multi-sensor feedback as described in claim 6, characterized in that, By identifying the heat growth trend in the local thermal imbalance region based on the heat accumulation evolution characteristics, the heat accumulation growth factors specifically include: Based on the heat accumulation evolution characteristics, the heat expansion boundary of the local thermal imbalance region at continuous sampling time is extracted; Based on the heat expansion boundary, the outward expansion trend of the heat accumulation range in the local thermal imbalance region is identified to obtain the outward expansion amount of heat accumulation. Based on the external expansion of the heat storage, the heat growth trend of the local thermal imbalance region is analyzed to obtain the heat storage growth factor.

8. The semiconductor thin film heating control method based on multi-sensor feedback as described in claim 1, characterized in that, The target injected heat flow reduction amount is obtained by gradient modulation of the thermal stress release intensity in the local thermal imbalance region to adapt to the chip coating temperature uniformity control. Specifically, this includes: The thermal stress release intensity is extracted based on the density of thermal stress release points and the intensity of elastic wave signals within the local thermal imbalance area. By applying the thermal stress release intensity to the gradient constraint of the heat flow reduction demand in the local thermal imbalance region, a heat flow gradient modulation factor is obtained. The injected heat flux reduction amount is graded and adjusted according to the heat flux gradient modulation factor to obtain the gradient modulation reduction amount. By correcting the current injected heat flow of the heating unit through the gradient modulation reduction amount, a target injected heat flow suitable for chip coating temperature uniformity control is obtained.

9. The semiconductor thin film heating control method based on multi-sensor feedback as described in claim 1, characterized in that, The heating unit is driven by the target injected heat flow to reduce the heat accumulation rate and thermal stress release intensity in the local thermal imbalance region to within the corresponding threshold, specifically including: The heat flow driving quantity of the heating unit is generated by injecting heat flow into the target; The output heat flow of the heating unit is locally reduced according to the heat flow driving amount, so that the local thermal imbalance area enters the heat flow regulation state. Under the heat flow regulation state, the heat accumulation rate and thermal stress release intensity of the local thermal imbalance region are continuously acquired; When the heat accumulation rate and the heat stress release intensity decrease to within their respective thresholds, the heating unit maintains a stable output according to the target injected heat flow.

10. A semiconductor thin film heating control system based on multi-sensor feedback, used to execute a semiconductor thin film heating control method based on multi-sensor feedback as described in any one of claims 1 to 9, characterized in that, The semiconductor thin film heating control system includes: The multi-sensor synchronous acquisition module is used to acquire the tangential heat flux density of the film surface at each measurement point through the heat flux density sensor array on the wafer carrier surface, and synchronously acquire the elastic wave signal excited by thermal stress through the acoustic emission sensor coupled to the base. The thermal imbalance distribution positioning module is used to calculate the heat flux divergence of each measuring point based on the tangential heat flux density of the membrane surface of adjacent measuring points, obtain the heat storage distribution, and perform time difference of arrival positioning on the elastic wave signal to obtain the distribution of thermal stress release points. The thermal imbalance region calibration module is used to determine the thermal imbalance confidence level of each measuring point based on the consistency between the heat accumulation distribution and the distribution of the thermal stress release points at the same measuring point, and to calibrate the measuring points whose thermal imbalance confidence level exceeds a preset threshold as local thermal imbalance regions. The target heat flux modulation module is used to determine the amount of heat flux reduction of the heating unit based on the heat accumulation rate of the local thermal imbalance region, and to perform gradient modulation of the amount of heat flux reduction by the thermal stress release intensity of the local thermal imbalance region to obtain the target heat flux adapted to the chip coating temperature uniformity control. A heat flow driven module is used to drive the heating unit by injecting heat flow into the target, so that the heat accumulation rate and heat stress release intensity of the local thermal imbalance region are reduced to within the corresponding threshold.

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