Temperature correction information calculating device, semiconductor manufacturing apparatus, program, and temperature correction information calculating method

Abstract

[Objective] To provide a technique for adjusting the preset temperature of heat treatment on an object. [Means of Achieving the Objective] This disclosure provides a temperature correction information calculation device for use with semiconductor manufacturing equipment. The semiconductor manufacturing equipment is configured to correct a preset temperature based on the accumulated film thickness on the inner wall of the semiconductor manufacturing equipment, and to perform a deposition process on an object by controlling the temperature using a heater to bring the temperature close to the corrected preset temperature. The temperature correction information calculation device includes a storage unit configured to store a temperature correction value for correcting the preset temperature; an acquisition unit configured to acquire a first heater power applied to the heater; a power prediction unit configured to predict a second heater power by adding the change in heater power caused by the change in preset temperature to the first heater power; and a temperature correction information generation unit configured to correct the temperature correction value based on the second heater power predicted by the power prediction unit. The first heater power is included in log information generated when the deposition process is performed.

Description

[Technical Field]

[0001] This disclosure relates to a temperature correction information calculation device, semiconductor manufacturing equipment, program, and method for calculating temperature correction information. [Previous Technology]

[0002] In the manufacturing process of semiconductor devices, thermal processing systems configured to perform processes such as semiconductor wafer deposition are known. In the thermal processing system, various processing conditions controlled by the semiconductor manufacturing equipment, such as preset temperature, pressure, and gas flow rate, are determined in the process formulation. The semiconductor manufacturing equipment repeatedly performs thermal processing to deposit a film on the semiconductor wafer. During this process, the deposit adheres to the inner wall surface of the semiconductor manufacturing equipment. If the cumulative film thickness of the deposit increases, the furnace temperature will still decrease even if the semiconductor manufacturing equipment maintains the preset temperature. Therefore, it is impossible to deposit a film with the desired thickness on the semiconductor wafer.

[0003] Heat treatment systems that correct preset temperatures based on accumulated film thickness are known (see, for example, Patent Document 1). Patent Document 1 discloses a technique for generating temperature correction information, wherein the accumulated film thickness is correlated with the amount of the preset temperature to be corrected. [Related Art Documents] [Non-Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2008-218558. [Summary of the Invention]

[0005] Problems to be solved by the present invention

[0006] This disclosure provides a technique for adjusting the preset temperature of heat treatment on an object. This is a means to solve the problem.

[0007] According to this disclosure, a temperature correction information calculation device for use with a semiconductor manufacturing apparatus is provided. The semiconductor manufacturing apparatus is configured to correct a preset temperature based on the accumulated film thickness on the inner wall of the semiconductor manufacturing apparatus, to bring the temperature close to the corrected preset temperature by using a heater, and to perform a deposition process on an object. The temperature correction information calculation device includes a storage unit configured to store a temperature correction value for correcting the preset temperature; an acquisition unit configured to acquire a first heater power applied to the heater; a power prediction unit configured to predict a second heater power by adding a change in heater power caused by a change in preset temperature to the first heater power; and a temperature correction information generation unit configured to correct the temperature correction value based on the second heater power predicted by the power prediction unit. The first heater power is included in log information generated when the deposition process is performed. Benefits of the Invention

[0008] A technology is available that can adjust the preset temperature of heat treatment on an object.

Implementation Method

[0010] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described. A heat treatment system according to an embodiment of the present disclosure and a method for calculating temperature correction information performed by the heat treatment system will be described with reference to the accompanying drawings. [Overview of Temperature Correction Based on Cumulative Film Thickness]

[0011] The heat treatment system performs multiple deposition processes in one cycle. Furthermore, during the deposition process, the heat treatment system uses a temperature calibration table to correct for preset temperatures defined in the process recipe. When generating the temperature calibration table, the heater power recorded in the log is taken into account. However, for heater power, the log is obtained from a given deposition process in one cycle (the user can select the log, but primarily selects the log from the first deposition process). Therefore, the heater power in the second and subsequent deposition processes may differ from the heater power in the first deposition process. If the temperature during film deposition is corrected based on a temperature calibration table corrected according to heater power different from the actual heater power, the target film thickness will not be obtained.

[0012] In view of the above, the heat treatment system according to the embodiment can accurately correct the temperature correction table by predicting the heater power in the second and subsequent deposition processes from the heater power in the first deposition process, so as to obtain a film thickness close to the target film thickness.

[0013] Details will be described below. [Including the overall configuration of the thermal processing system for semiconductor manufacturing equipment]

[0014] Figure 1 is a schematic diagram illustrating an example configuration of a heat treatment system. As shown in Figure 1, the heat treatment system 1 according to an embodiment includes a plurality of semiconductor manufacturing equipment 2 (semiconductor manufacturing equipment 21 to 2n in Figure 1), a host 3, a temperature correction information computing device 4, and networks 5 and 6. The above components are interconnected via networks 5 and 6. In addition, the heat treatment system 1 includes a measuring device 60 configured to measure the state (e.g., the state of the film) of the object (hereinafter referred to as "semiconductor wafer") processed by each semiconductor manufacturing equipment 2.

[0015] The semiconductor manufacturing equipment 2 may include various types of equipment depending on the process. For example, the semiconductor manufacturing equipment 2 may include a deposition apparatus configured to form a thin film on a semiconductor wafer, an oxidation apparatus configured to perform an oxidation process for oxidizing the surface regions of the semiconductor wafer, and a diffusion apparatus configured to diffuse (dope) impurities into the surface regions of the semiconductor wafer. In the following description, a batch vertical thermal processing apparatus illustrated in FIG2 will be used as an example of a semiconductor manufacturing equipment. Furthermore, in this embodiment, a deposition process will be described as a process performed on a semiconductor wafer.

[0016] Figure 2 is a schematic cross-sectional view of an example of a semiconductor manufacturing apparatus 2. As shown in Figure 2, the semiconductor manufacturing apparatus 2 includes a reaction tube 11 having an approximately cylindrical shape. The reaction tube 11 is configured such that the longitudinal direction of the reaction tube 11 is in the vertical direction. The reaction tube 11 may be formed of a material with excellent heat resistance and corrosion resistance, such as quartz.

[0017] An exhaust pipe 12 for venting gas from the reaction tube 11 is hermetically connected to the upper side of the reaction tube 11. The exhaust pipe 12 is provided with a pressure regulator 13 including a valve and a vacuum pump. The pressure regulator 13 regulates the interior of the reaction tube 11 to a desired pressure (a certain degree of vacuum).

[0018] A manifold 14 with an approximately cylindrical shape is disposed below the reaction tube 11. The upper end of the manifold 14 is hermetically connected to the lower end of the reaction tube 11.

[0019] The cover 15 is positioned below the manifold 14 (reaction tube 11). The cover 15 is configured to move vertically via the boat elevator 16. In this configuration, when the cover 15 is raised by the boat elevator 16, the bottom end (furnace opening) of the manifold 14 (reaction tube 11) is closed, and when the cover 15 is lowered by the boat elevator 16, the bottom end (furnace opening) of the reaction tube 11 is opened.

[0020] Above the cover 15, a crystal boat 18 is mounted on a thermally insulating tube (thermal insulator) 17. The crystal boat 18 is a wafer holding device that houses (holds) objects such as semiconductor wafers W. In this embodiment, the crystal boat 18 is configured to house a plurality of semiconductor wafers W (e.g., 150 semiconductor wafers W) at predetermined intervals in the vertical direction. In order to load the semiconductor wafers W into the reaction tube 11, the semiconductor wafers W are housed in the crystal boat 18 and the cover 15 is raised by a boat lift 16.

[0021] For example, a heater 19, which is composed of a resistance heating element, is disposed around the reaction tube 11. The heater 19 heats the interior of the reaction tube 11 to a predetermined temperature, and thus heats the semiconductor wafer W to a predetermined temperature.

[0022] The heater 19 includes heaters 191 to 195 arranged, for example, in five orders. Electricity is supplied to heaters 191 to 195 individually, thereby controlling each heater 191 to 195 individually by power controllers 196 to 200. In this way, as illustrated in FIG3, the interior of the reaction tube 11 is divided into five zones (zones 1 to 5) by the heaters 191 to 195. Note that the number of zones is not limited to five. The interior of the reaction tube 11 may be divided into two or more zones, or it may not necessarily be divided into zones.

[0023] The manifold 14 is provided as having a plurality of gas supply pipes for supplying gas to the reaction pipe 11. In this embodiment, three gas supply pipes 20 to 22 are provided. The feed gas for membrane deposition and the carrier gas are supplied to the gas supply pipes 20 to 22 via flow rate regulators 23 to 25. Each of the flow rate regulators 23 to 25 is configured by a mass flow controller (MFC) or the like for regulating the gas flow rate.

[0024] Five temperature sensors (thermocouples) (not shown) are arranged in a vertical row on the inner wall of the reaction tube 11. Each temperature sensor is covered by a quartz tube or the like to prevent metal contamination of the semiconductor wafer W, and each temperature sensor is placed in the corresponding area shown in FIG3.

[0025] The semiconductor manufacturing equipment 2 includes a controller 50 configured to control processing parameters, such as the temperature of the processing atmosphere, gas flow rate, and pressure in the reaction tube 11. The controller 50 receives signals from temperature sensors, pressure sensors, and the like (not shown), and outputs control signals to power controllers 196 to 200, pressure regulators 13, and flow rate regulators 23 to 25 of heaters 191 to 195. [Hardware configuration of the controller]

[0026] Figure 4 is a diagram illustrating an exemplary configuration of the controller 50. The controller 50 includes a recipe storage 51, a read-only memory (ROM) 52, a random access memory (RAM) 53, an input / output (I / O) port 54, a central processing unit (CPU) 55, a communication unit 56, and a bus 57. The above components are interconnected via the bus 57.

[0027] The recipe storage 51 stores process recipes that define the control program based on the type of deposition process performed by the semiconductor manufacturing equipment 2. The process recipe is processing information prepared for each process actually performed by the operator, and this processing information defines the temperature changes of each element, the pressure changes in the reaction tube 11, the start and stop times of gas supply, the amount of gas to be supplied, and similar factors during the period from loading the semiconductor wafer W into the reaction tube 11 to unloading the semiconductor wafer W after processing. With a process recipe, a preset film thickness, a preset temperature for each device, and similar factors can be specified for heat treatment. In the case of a typical batch heat treatment equipment, a single process recipe is prepared for all semiconductor wafers W. However, in this embodiment, a predetermined process recipe is prepared for each area shown in FIG3, so that the processing results of the semiconductor wafer W are consistent.

[0028] Furthermore, the process recipe includes an optimal value calculation recipe. The optimal value calculation recipe is used to correct the preset temperature of each device to the optimal temperature (optimal value) according to the temperature correction table, and set the corrected temperature as the preset temperature. Therefore, when the semiconductor manufacturing equipment 2 performs heat treatment based on the optimal value calculation recipe, it calculates the optimal value of the preset temperature of zones 1 to 5, and sets the calculated optimal value as the preset temperature.

[0029] As described above, the preset temperature is calibrated by the semiconductor manufacturing equipment 2. However, the temperature calibration information calculation device 4 can provide the semiconductor manufacturing equipment 2 with a process recipe in which the preset temperature is calibrated according to a temperature calibration table. Alternatively, any device can be used to calibrate the preset temperature, as long as the semiconductor manufacturing equipment 2 can execute the process recipe at the calibrated preset temperature.

[0030] ROM52 is configured by means of EEPROM, flash memory, hard disk or the like, and is used as a recording medium for storing the operating program of CPU55 and the like.

[0031] RAM53 is used as a working area for CPU55. For example, RAM53 stores the number of times the process is executed using semiconductor manufacturing equipment 2. The cumulative film thickness of the deposits attached to the interior of semiconductor manufacturing equipment 2 can be identified based on the number of process executions and the preset film thickness stored in the recipe storage 51.

[0032] I / O port 54 sends measurement signals regarding temperature, pressure, and gas flow rate to CPU 55, and outputs control signals from CPU 55 to various components (power controllers 196 to 200, flow rate regulators 23 to 25, and pressure regulator 13). The operator operates the semiconductor manufacturing equipment 2 connected to I / O port 54 via the operation panel 58.

[0033] The CPU 55 constitutes the main component of the controller 50. The CPU 55 is configured to execute the operating program stored in the ROM 52 according to the instructions from the operation panel 58 so as to control the operation of the semiconductor manufacturing equipment 2 based on the process recipe stored in the recipe storage 51.

[0034] The communication unit 56 is configured to perform communication between the semiconductor manufacturing equipment 2, the host 3, and the temperature correction information computing device 4 via LANs 5 and 6. The bus 57 transmits information between these components.

[0035] The host computer 3 is configured to control the overall semiconductor manufacturing equipment 2 and execute programs for instructing the semiconductor manufacturing equipment 2 to perform heat treatment or the like. Note that the host computer 3 has a known configuration (not shown). [Exemplary hardware configuration of temperature correction information calculation device]

[0036] Figure 5 is a diagram illustrating an exemplary hardware configuration of the temperature correction information calculation device. The temperature correction information calculation device 4 executes a program for generating a temperature correction table based on the cumulative film thickness (number of film depositions) in order to reduce the difference between the furnace temperature and the preset temperature caused by the influence of the cumulative film thickness in the semiconductor manufacturing equipment 2.

[0037] The temperature correction information computing device 4 includes a CPU 501, a ROM 502, and a RAM 503. The CPU 501, ROM 502, and RAM 503 form a so-called computer. Furthermore, the temperature correction information computing device 4 includes an auxiliary storage device 504, an operating device 505, a display device 506, an interface (I / F) device 507, and a drive device 508. The hardware components of the temperature correction information computing device 4 are interconnected via a bus 509.

[0038] The CPU 51 executes a number of programs installed in the auxiliary storage device 504.

[0039] ROM 502 is a non-volatile memory used as the main storage device. ROM 502 stores various programs, data and similar data required by CPU 501 to execute various programs installed in auxiliary storage device 504.

[0040] RAM 503 is a volatile memory such as dynamic random access memory (DRAM) or static random access memory (SRAM) and is used as the primary storage device. When the CPU 501 executes various programs, RAM 53 provides a working area in which various programs installed in the auxiliary storage device 504 are deployed.

[0041] The auxiliary storage device 504 is a non-volatile, high-capacity storage device that stores a variety of programs. The auxiliary storage device 504 may be a non-volatile, high-capacity storage device such as a hard disk drive (HDD) or a solid-state drive (SSD).

[0042] The operating device 505 is an input device used when the administrator inputs various commands into the temperature correction information calculation device 4. The display device 506 is a display device that displays internal information of the temperature correction information calculation device 4 and information obtained from external devices.

[0043] The I / F device 507 is a connection device for connecting to the LAN6 and communicating with the controller 50 of the semiconductor manufacturing equipment 2. The I / F device 507 also communicates with the measuring device 60 and the host 3.

[0044] The drive device 508 is a device for mounting a recording medium therein. The recording medium may be a medium that records information optically, electrically, or magnetically, such as a CD-ROM, floppy disk, or magneto-optical disk. The recording medium may be a semiconductor memory that records information electrically, such as a ROM, or flash memory, or the like.

[0045] When, for example, a distributed recording medium is set in the drive device 508 and numerous programs recorded on the recording medium are read by the drive device 508, the numerous programs to be installed in the auxiliary storage device 504 are installed. Alternatively, the numerous programs to be installed in the auxiliary storage device 504 can be downloaded from a predetermined server and installed in the auxiliary storage device 504. [Function of the temperature correction information calculation device]

[0046] Referring next to FIG6, the information stored by the temperature correction information calculation device 4 and the functional configuration of the temperature correction information calculation device 4 will be described. FIG6 is a functional block diagram illustrating an exemplary functional configuration of the temperature correction information calculation device 4.

[0047] The temperature correction information calculation device 4 includes an acquisition unit 61, a temperature correction information generation unit 62, a model training unit 63, and a power prediction unit 64. The function of the temperature correction information calculation device 4 is implemented by the CPU 501 shown in FIG5 executing the program loaded from the auxiliary storage device 504 into the RAM 503.

[0048] The acquisition unit 61 acquires log information from the controller 50 of the semiconductor manufacturing equipment 2 regarding the thermal processing performed on the semiconductor wafer W according to the process recipe. The log information includes preset temperature, heater power, and the like in a time series. The acquisition unit 61 acquires the heater power applied to the heater, which is included in the log information generated when the deposition process is performed. Furthermore, the acquisition unit 61 can acquire the monitored film thickness of the monitored semiconductor wafer W from the measurement device 60. The number of times the process is performed using the semiconductor manufacturing equipment 2 can be identified using the log information. Therefore, the cumulative film thickness of the deposits adhering to the interior of the semiconductor manufacturing equipment 2 can be identified based on the number of process performances and the preset film thickness stored in the process recipe.

[0049] The temperature correction information generation unit 62 uses a model, which will be described later, to obtain the relationship between the preset temperature included in the log information and the monitored film thickness measured by the measuring device 60, in order to generate a temperature correction table. Furthermore, the temperature correction information generation unit 62 corrects the temperature correction values ​​in the temperature correction table so that the heater power is not saturated (0% or 100%).

[0050] The model training unit 63 updates the model stored in the model storage 72. Updating the model means changing the model based on the deposition results and the target film thickness, so that the model more accurately reproduces the relationship between the preset temperature and the film thickness in the semiconductor manufacturing equipment 2. The term "update" may be referred to as "training". In this embodiment, the updated model may be referred to as the trained model. In this embodiment, model training is not a characteristic part of the present invention and is therefore not described in detail.

[0051] The power prediction unit 64 predicts the heater power in the second and subsequent deposition processes based on the heater power recorded in the log information of the first deposition process in a cycle. Many users tend to select the log information of the first deposition process in a cycle; however, it is not necessary to select the log information of the first deposition process in a cycle. The temperature-to-power table and the temperature correction table are used to predict the heater power. In addition, the cumulative film thickness-to-power table and the change in cumulative film thickness can be further used to predict the heater power.

[0052] Furthermore, the temperature correction information calculation device 4 includes a memory 70 configured via RAM 503 or auxiliary storage device 504. The memory 70 includes a temperature correction table memory 71, a model memory 72, and a table memory 73.

[0053] Figure 7 is an example of a temperature calibration table. The temperature calibration table shows the relationship between the cumulative film thickness of the deposits adhering to the interior of the semiconductor manufacturing equipment 2 and the temperature calibration value at each predetermined temperature (each preset temperature base) in the semiconductor manufacturing equipment 2. In the temperature calibration table of Figure 7, the temperature in the semiconductor manufacturing equipment 2 is set to a predetermined temperature, and the temperature calibration value used when a deposit with a predetermined cumulative film thickness is adhering to the interior of the semiconductor manufacturing equipment 2 is associated with these areas.

[0054] In the example of Figure 7, in the initial state before the process formulation is executed, a film thickness of tk1 [nm] is formed on the semiconductor wafer. For example, tk1 can be 100 [nm]; however, tk1 can vary depending on the process formulation. The process formulation includes six deposition processes. These six deposition processes are performed in one cycle of thermal processing. In one deposition process, a predetermined film thickness Δtk is formed. The cumulative film thickness increases, for example, tk2 = tk1 + Δtk, tk3 = tk2 + Δtk, ..., and in the sixth deposition process, a film thickness of tk6 + Δtk can be obtained. Note that the number of deposition processes included in one cycle of thermal processing can be arbitrary, and the film thickness formed in one deposition process can vary depending on the process formulation.

[0055] In the case where the semiconductor manufacturing equipment 2 corrects the preset temperature of region 1 with a cumulative film thickness of tk2 [nm], the semiconductor manufacturing equipment 2 calculates "the preset temperature included in the process recipe + 0.1"ºC as the corrected preset temperature.

[0056] Please note that if any preset temperature and any cumulative film thickness are different from the values ​​defined in the temperature calibration table, the semiconductor manufacturing equipment 2 may perform interpolation for adjustment.

[0057] Furthermore, the temperature calibration table is an example of storing temperature calibration values ​​used to calibrate a preset temperature. The storage format of the temperature calibration values ​​is not limited to tabular format. For example, the temperature calibration table can be represented in function format or graphical format.

[0058] Figure 8 is a schematic diagram illustrating the model stored in the model storage 72. The model is prepared based on each preset temperature. In the example of Figure 8, a model prepared for a given preset temperature is depicted. As used herein, the term "model" refers to data generated and used to control the semiconductor manufacturing equipment 2 by learning the relationship between preset temperature and power variation in advance.

[0059] The model shown in Figure 8(a) represents the temperature change in a given tank when the temperature in each zone increases by 1ºC. Specifically, when the temperature in a given zone changes, the temperature in other zones also changes. As described, there may be cases where the temperature of the semiconductor wafer is not the same as the preset temperature due to factors such as the temperature distribution in the reaction tube 11. The actual temperature of the semiconductor wafer W is calculated based on the model shown in Figure 8(a) when the preset temperatures of these zones differ by 1ºC.

[0060] In the model illustrated in Figure 8(b), the change in film thickness is defined for each region when the temperature difference is 1ºC. That is, the temperature change is related to the change in film thickness. For the semiconductor wafer W, the film thickness formation is based on the actual temperature of the semiconductor wafer W during heat treatment (when other parameters such as gas type and pressure are assumed to be constant) and the heat treatment time. The model illustrated in Figure 8(b) represents the correspondence between the actual temperature and the film thickness of the semiconductor wafer W based on various findings. For example, when the temperature difference in region 1 is 1ºC (this temperature is corrected based on the model illustrated in Figure 8(a), the change in film thickness is K [nm].

[0061] An example of generating a temperature correction table for region 1 using the model shown in Figure 8(b) will be described. An evaluation function as described below will be used to generate the temperature correction table. Evaluation function J = f(residual with target film thickness, model representing temperature and film thickness variation, temperature variation)

[0062] As a model representing the changes in temperature and film thickness, a model representing the "preset temperature versus wafer temperature" can be obtained by referring to the model shown in Figure 8(a) representing "preset temperature versus wafer temperature" and the model shown in Figure 8(b) representing "wafer temperature versus deposition amount". Then, the optimal value is obtained by finding the combination of temperature changes that minimize the evaluation function J within the range of satisfying constraints. The constraints include the condition that the heater power is not saturated and the condition that the temperature does not exceed the range specified by the user.

[0063] As described above, a temperature correction table is generated by referring to the two models shown in FIG8. Therefore, it is desirable for the two models to be as accurate as possible. For this reason, the temperature correction information calculation device 4 has the function of training the model. The model training unit 63 updates (trains) the model based on the difference between the monitored film thickness and the target film thickness. As a concept, when the difference between the monitored film thickness and the target film thickness as a deposition result increases, the model training unit 63 adds the temperature change of the semiconductor wafer W in FIG8(a) when the temperature difference is 1ºC, and adds the film thickness change in FIG8(b) when the temperature difference is 1ºC.

[0064] More specifically, the model training unit 63 updates the two models by applying the difference between the monitored film thickness and the target film thickness to an extended Kalman filter or the like. The method of updating the models is not a characteristic part of the invention and is therefore not described in detail. In the following description, unless otherwise specified, both models illustrated in FIG8 are included in any model.

[0065] Please note the examples where each model stores information about the temperature change of the semiconductor wafer W with respect to a preset temperature, or about the film thickness change with respect to a preset temperature. The information storage format is not limited to tabular format. For example, the model can be represented in function format or graphical format.

[0066] Figure 9(a) illustrates an example of a temperature-to-power meter stored in the meter memory 73. The temperature-to-power meter is one of the models. It is used to calculate the change in heater power caused by a change in preset temperature. As shown in Figure 9(a), the change in heater power required to change the temperature in each zone by 1ºC is set. That is, the change in temperature is related to the change in heater power. Actual values ​​may vary; however, as an example, actual values ​​may be percentages (%) on the order of one-tenth or one-thousandth.

[0067] Figure 9(b) illustrates an example of a cumulative film thickness / power table stored in table memory 73. The cumulative film thickness / power table is used to calculate the change in heater power caused by a change in cumulative film thickness. The cumulative film thickness / power table shown in Figure 9(b) represents the amount of power change when heat transfer changes due to an increase in the cumulative film thickness of deposits on the walls of the chamber. That is, the change in cumulative film thickness is related to the change in heater power. As the cumulative film thickness increases, the heater power tends to saturate, and the output value of the heater power indicates a similar trend. That is, the slope of the change in heater power changes according to the cumulative film thickness. Details will be described later. Please note that the values ​​in Figure 9(b) are merely examples for illustrative purposes.

[0068] Please note the examples of temperature versus power meters and cumulative film thickness / power meters storing information on changes in heater power. The information storage format is not limited to tabular format. For example, each of the temperature versus power meter and cumulative film thickness / power meter can be represented in function format or graphical format. [Overview of temperature correction function based on cumulative film thickness]

[0069] Figure 10 is a diagram illustrating an exemplary deposition result obtained by using a temperature correction table to correct the temperature based on the cumulative film thickness and performing a deposition process.

[0070] (1) First, the semiconductor manufacturing equipment 2 performs a heat treatment based on a temperature correction table before correction, which corresponds to the "pre-temperature correction" heat treatment depicted in FIG10. The "pre-temperature correction" heat treatment refers to the initial heat treatment (including the six deposition processes). The film thickness formed in a deposition process is denoted by Δtk [nm]. As shown in FIG10(a), each deposition process is performed with the goal of depositing a film with a thickness of Δtk [nm] on the semiconductor wafer W; however, as the cumulative film thickness on the walls of the chamber increases, the film thickness deviates from the target thickness Δtk [nm].

[0071] In Figure 10(a), the horizontal axis indicates the cumulative film thickness, and the vertical axis indicates the monitored film thickness. The monitored film thickness varies around Δtk. In Figure 10(a), a six-deposition process is performed in one cycle. The graph indicates the monitored film thickness formed in a single deposition process in relation to the cumulative film thickness accumulated in the six-deposition process. Specifically, the complex curves in the graph of Figure 10(a) represent the monitored film thickness of semiconductor wafers W arranged vertically at different positions on the boat 18. The gas concentration varies depending on the vertical position in the reaction tube 11. Therefore, semiconductor wafers W arranged at different positions are pre-extracted to monitor the film thickness of semiconductor wafers W. The semiconductor wafers W whose film thickness is monitored and measured are those semiconductor wafers W disposed in each region.

[0072] As the number of deposition processes increases, the cumulative film thickness on the inner wall surface of the semiconductor manufacturing equipment increases. If the cumulative film thickness increases, the furnace temperature will still decrease even when the furnace temperature system is controlled at the same processing temperature. In such cases, it will be impossible to form a thin film with the desired film thickness on the semiconductor wafer W. As illustrated in Figure 10(a), as the cumulative film thickness increases, the monitored film thickness tends to gradually increase.

[0073] (2) The temperature correction information generation unit 62 generates the temperature correction table shown in Figure (10)b by using the model shown in Figure 8 to obtain the relationship between the preset temperature included in the log information and the monitored film thickness obtained from the measuring device 60. The immediate generation of the temperature correction table after the initial heat treatment is called the first calculation process. The generation of the temperature correction table corresponds to the "calculation" process depicted in Figure 10. In the second and subsequent calculation processes after the generation of the temperature correction table, the model can be updated by user setting or automatic determination. Automatic determination means that if the result obtained based on the temperature correction table calculated in the first calculation process does not improve, the accuracy of the model is determined to be poor, and the model is updated in the second and subsequent calculation processes to make the film thickness close to the target thickness. Furthermore, the model can be automatically updated in response to the detection of interference or the like.

[0074] Please note that the old calculation data is used to update (train) the model. Since there is no old calculation data in the initial heat treatment, the model is not updated in the first calculation process.

[0075] (3) Semiconductor manufacturing equipment 2 performs heat treatment based on a temperature correction table, which corresponds to the "temperature-corrected" heat treatment depicted in FIG10. FIG10(c) depicts the deposition result of a deposition process performed based on a temperature correction table in which a preset temperature is corrected. In FIG10(c), after temperature correction, the monitored film thickness tends to remain stable even as the cumulative film thickness increases. [Generate temperature correction table]

[0076] Figure 11 is a flowchart illustrating an example of the process by which the temperature correction information generation unit 62 generates a temperature correction table.

[0077] First, before starting the deposition process, the user establishes a process recipe (configures a preset temperature value or similar) for performing the deposition process (step S1). At this time, the temperature calibration table has not yet been optimized, so the user can set any value as the preset temperature value. The temperature calibration information generation unit 62 can set a predetermined initial value as the preset temperature value on behalf of the user.

[0078] The semiconductor manufacturing equipment 2 uses the process recipe and temperature calibration table established in step S1 to perform one cycle of the deposition process (up to 20 deposition processes) (step S2).

[0079] The measuring device 60 measures the film thickness formed in each deposition process in one cycle (step S3). After one cycle, if the reproducibility of the film thickness meets a predetermined criterion, the process ends. If the criterion is not met, the process continues to step S4.

[0080] The temperature correction information generation unit 62 calculates the optimal value of the temperature correction table (step S4) using the log of a given deposition process selected by the user from the deposition process performed in step S2, the measurement results obtained in step S3, the values ​​of the temperature correction table used in the deposition process, and the model. Furthermore, in step S4, based on the heater power and the "model representing the power change caused by a 1ºC temperature change (temperature versus power table)," the temperature correction information generation unit 62 corrects the temperature correction table within the range where the heater power is not saturated. Details will be described with reference to FIG12.

[0081] The temperature correction information generation unit 62 updates the value of the temperature correction table to the optimal value calculated in step S4 (step S5).

[0082] The temperature correction information calculation device 4 repeats steps S2 to S5, including performing the deposition process, calculating the optimal value, and updating the temperature correction table, until the reproducibility of the desired film thickness is obtained. [Difficulties caused by heater power saturation]

[0083] The role of heater power in updating the temperature calibration table will be described, as well as the inconvenience that may occur when calibrating the temperature calibration table by using the heater power selected by the user in step S2.

[0084] Figure 12 is a diagram illustrating the role of heater power in updating the temperature correction table. As in step S2 of Figure 11, when the semiconductor manufacturing equipment 2 performs a deposition process, a log of the power output status (heater power) is recorded (Figure 12(a)). In a contrasting art (e.g., the prior art), the user selects the log of the first deposition process in a cycle and inputs the heater power in the log into the temperature correction information calculation device 4 (software). In the prior art, it is assumed that the heater power of subsequent deposition processes in a cycle is the same as the heater power recorded in the selected log of the first deposition process.

[0085] In this embodiment, when calculating the optimal value in step S4 of FIG11, the temperature correction information generation unit 62 determines that the heater power may differ from the upper and lower limits of the percentage recorded in the log. For example, if the heater power recorded in the log is 10%, the lower limit is 0.1% and the upper limit is 99.9% (FIG. 12(b)). Note that the 0.1% on both sides of the upper and lower limits is an offset.

[0086] Next, the temperature correction information generation unit 62 determines the range in which the temperature value can change by combining the determined "power change range" and the "model representing the power change caused by a 1ºC temperature change (temperature versus power table)" (Fig. 12(c)). If the heater power read from the log is 100%, the temperature correction information generation unit 62 changes the temperature to decrease the heater power. Conversely, if the heater power is 0%, the temperature correction information generation unit 62 changes the temperature to increase the heater power. That is, the temperature correction information generation unit 62 corrects the temperature correction table based on the heater power predicted by the power prediction unit 64. As described above, if the heater power is saturated, the temperature is changed accordingly.

[0087] However, as in the comparative art, if it is assumed that the heater power is the same in all deposition processes in a cycle, the following difficulties will occur.

[0088] If the heater power recorded in the log of the selected deposition process is "1%", then the heater power in other deposition processes in a cycle is assumed to be "1%". Even when the heater power in all deposition processes in a cycle changes within the range of "-0.9%" to "+98.9%", the heater power is not saturated. However, there may be a case where the heater power in any deposition process other than the selected deposition process is actually "0.5%". In this case, the minimum value at which the heater power can decrease is "0.4%", but there is a possibility that the heater power may decrease by "0.9%". If the deposition process is performed using a correction value that causes the "0.5%" heater power to decrease by "0.9%", the heater power will saturate. Therefore, no improvement effect can be obtained.

[0089] In view of the above, in this embodiment, the temperature correction information generation unit 62 predicts the heater power in each deposition process to generate a temperature correction table.

[0090] Please note that users can select logs for all deposition processes in a cycle, but usability will be reduced. The temperature correction information generation unit 62 (software) can automatically select logs for all deposition processes in a cycle, but it may select logs incorrectly. In such cases, the user will be required to confirm (or in some cases correct) the logs automatically selected in a cycle. [Predicted heater power]

[0091] Figure 13 is a schematic diagram illustrating a method for predicting heater power. Based on the heater power (hereinafter referred to as "Pw0", an example of "first heater power") included in the log of the deposition process selected by the user in a deposition process cycle (e.g., the log of the first deposition process), the power prediction unit 64 predicts the heater power in the next deposition process (hereinafter referred to as "Pwn", where n=2 (maximum 20)). The heater power "Pwn" is an example of "second heater power".

[0092] Pwn = Pw0 + (i) +(ii) …… (1) where (i) represents the change in heater power due to the change in the current temperature value, and (ii) represents the change in heater power due to the change in cumulative film thickness. The above (i) is calculated based on the temperature versus power meter and the temperature correction table used in the deposition process. The above (ii) is calculated based on the cumulative film thickness versus power meter and the change in cumulative film thickness.

[0093] Figure 14 is a diagram illustrating the method for calculating (i) the change in heater power caused by a change in the current temperature value. Figure 14(a) depicts a temperature-to-power table, while Figure (14)b depicts a temperature correction table. For each zone, the value representing the change in heater power in the column of the temperature-to-power table is multiplied by the corresponding temperature correction value in the temperature correction table. For example, in the case of zone 4 and a cumulative film thickness of 100 [nm], the value in the column of zone 4 of the temperature-to-power table is multiplied by the temperature correction value of zone 4 in the temperature correction table as follows: D1 · 0.2, D2 · 0.2, D3 · 0.2, D4 · 0.2, D5 · 0.2

[0094] The values ​​are calculated in the same manner for zones 1 to 3 and zone 5. Next, the power prediction unit 64 adds up the values ​​obtained by multiplying the values ​​in the column direction of the temperature correction table. In this way, the change in heater power in each zone is calculated. For example, the change in heater power in each of zones 1 to 5 due to the change in the current temperature value is as follows. (i) Change in heater power due to change in current temperature (Zone 1) = A1 · 0.1 + B1 · (-0.3) + C1 · (0.0) + D1 · 0.2 + E1 · (-0.1) (i) Change in heater power due to change in current temperature (Zone 2) = A2 · 0.1 + B2 · (-0.3) + C2 · (0.0) + D2 · 0.2 + E2 · (-0.1) (i) Change in heater power due to change in current temperature (Zone 3) = A3 · 0.1 + B3 · (-0.3) + C3 · (0.0) + D3 · 0.2 + E3 · (-0.1) (i) Change in heater power due to change in current temperature (Zone 4) = A4 · 0.1 + B4 · (-0.3) + C4 · (0.0) + D4 · 0.2 + E4 · (-0.1) (i) Change in heater power due to change in current temperature (zone 5) = A5 · 0.1 + B5 · (-0.3) + C5 · (0.0) + D5 · 0.2 + E5 · (-0.1)

[0095] Please note that when calculating (i), the temperature-to-power table I used in the deposition process of the first cycle is employed. That is, the temperature correction table I is the temperature correction table before calculating the optimal value.

[0096] Temperature correction table II is obtained by calculating the optimal value based on, for example, the information in temperature correction table I used for calculation (i), the deposition results, and the heater power obtained from the deposition process log. Temperature correction table II is used for the deposition process in the next cycle.

[0097] That is, the power prediction unit 64 uses the old temperature correction table I to predict the heater power, and the temperature correction information generation unit 62 generates a new temperature correction table II.

[0098] Figure 15 is a diagram illustrating the method for calculating (ii) the change in heater power due to the change in cumulative film thickness. Figure 15(a) depicts the cumulative film thickness versus power table. Figure 15(b) depicts the change in film thickness for each region when the temperature difference is 1ºC (Figure 15(b) is the same as Figure 8(b)). The change in heater power in each region is obtained by multiplying the value in Figure 15(a) by the value in Figure 15(b). For example, if the cumulative film thickness is 100 [nm], the change in heater power in each of regions 1 to 5 is calculated as follows. (ii) Change in heater power due to cumulative film thickness change in Zone 1 = 0.03 · K (ii) Change in heater power due to cumulative film thickness change in Zone 2 = 0.03 · L (ii) Change in heater power due to cumulative film thickness change in Zone 3 = 0.02 · M (ii) Change in heater power due to cumulative film thickness change in Zone 4 = 0.02 · N (ii) Change in heater power due to cumulative film thickness change in Zone 5 = 0.03 · O

[0099] Please note that in Figure 15, the change in power based on the cumulative film thickness is multiplied by the change in film thickness due to temperature change. However, we believe that "(ii) the change in heater power due to the change in cumulative film thickness" tends to saturate as the cumulative film thickness increases. Therefore, the correlation satisfying "power change = f(cumulative film thickness)" can be obtained in advance, and the change in heater power due to the change in cumulative film thickness can be interpolated based on this correlation during prediction.

[0100] Furthermore, the change in film thickness when the temperature difference is 1ºC can be set for each cumulative film thickness as shown in Figure 15(b). Furthermore, the item (ii) in Formula (1) has little effect on the heater power, so there is no need to use the item (ii) in Formula (1) for the prediction of heater power.

[0101] Figure 16 is a flowchart illustrating an example of the process by which the temperature correction information generation unit 62 generates a temperature correction table. In Figure 16, the main differences from Figure 11 will be described. Steps S1 to S3 in Figure 16 are the same as steps S1 to S3 in Figure 11.

[0102] In step S3, if the reproducibility of the film thickness does not meet the predetermined criteria after one cycle, the process continues to step S3-2.

[0103] In step S3-2, the power prediction unit 64 uses a temperature-to-power meter and a temperature correction table used in the deposition process to calculate (i) the change in heater power based on the change in the current temperature value. Furthermore, the power prediction unit 64 uses a cumulative film thickness-to-power meter and a film thickness change (FIG. 15(b)) to calculate (ii) the change in heater power based on the change in cumulative film thickness. The power prediction unit 64 adds (i) and (ii) to the heater power Pw0 included in the log of the given deposition process selected by the user in step S2. Then, the power prediction unit 64 predicts the heater power in deposition processes other than the given deposition process (e.g., if a deposition process with a cumulative film thickness of 0 [nm] is selected, the power prediction unit 64 predicts the heater power in deposition processes with cumulative film thicknesses of 50 and 100 [nm]).

[0104] In step S4, as shown in FIG12, the temperature correction information generation unit 62 determines the range in which the temperature value can change by combining the determined "power change range" and "model representing the power change caused by a 1ºC temperature change (temperature versus power meter)". If the predicted heater power is 100%, the temperature correction information generation unit 62 changes the temperature correction value of the temperature correction meter to reduce the heater power. Conversely, if the predicted heater power is 0%, the temperature correction information generation unit 62 changes the temperature correction value of the temperature correction meter to increase the heater power.

[0105] Accordingly, the temperature correction information calculation device 4 according to the embodiment can use the predicted heater power to correct the temperature correction table, instead of using the heater power selected by the user in the deposition process. Therefore, the accuracy of temperature control during the deposition process can be improved.

[0106] Figure 17 is a diagram illustrating the effect obtained by predicting heater power as described in the above embodiments. (1) Availability

[0107] First, in the comparative technology, the user can select a log of a deposition process from a deposition process in a cycle. Therefore, improved usability can be provided. In this embodiment, the advantage of providing improved usability can be maintained. (2) Calculation accuracy

[0108] In comparative technologies, the heater power in one deposition process within a cycle is considered as the heater power in all deposition processes. Therefore, the accuracy of the temperature calibration table calculation decreases. Conversely, in this embodiment, the heater power in all deposition processes within a cycle is predicted. Accordingly, the accuracy of the temperature calibration table calculation can be improved. [Main Benefits]

[0109] As described above, the heat treatment system according to the embodiment can predict the heater power for each deposition process in a cycle. Therefore, when the heater power is saturated, the heat treatment system according to the embodiment can correct the temperature correction table to prevent the heater power from becoming saturated. Accordingly, the semiconductor manufacturing equipment 2 can perform the deposition process while controlling the temperature, thereby making it possible to easily obtain the target film thickness. [Other Configurations]

[0110] In this embodiment, the temperature correction information calculation device 4 shown in FIG1 trains a model and generates a temperature correction table. However, the semiconductor manufacturing apparatus 2 may include the functionality of the temperature correction information calculation device 4.

[0111] Furthermore, the temperature calibration information computing device 4 can be a server connected to a network. The semiconductor manufacturing equipment 2 can communicate with the temperature calibration information computing device 4 to obtain a temperature calibration table. The temperature calibration information computing device 4 can be permanently located on the Internet or permanently located nearby.

[0112] The heat treatment system 1 shown in Figure 1 is an example, and there are obviously many system configuration examples depending on the application and purpose. The devices in Figure 1, such as the host 3, semiconductor manufacturing equipment 2, measuring device 60, and temperature correction information calculation device 4, are examples.

[0113] For example, the heat treatment system 1 may have various configurations, such as an integrated configuration of at least two of the host 3, semiconductor manufacturing equipment 2, measuring device 60, and temperature correction information calculation device 4, or a further divided configuration. For example, a temperature correction information calculation device 4 may be provided for each semiconductor manufacturing equipment 2.

[0114] The semiconductor manufacturing equipment 2 disclosed herein is not limited to batch equipment, but may be a single wafer deposition equipment that processes a single substrate at a time or a semi-batch equipment.

[0115] The process performed by the semiconductor manufacturing equipment is not limited to the deposition process. The semiconductor manufacturing equipment can be used as an oxidation equipment for performing an oxidation process on the surface area of ​​an oxidized semiconductor wafer, a diffusion equipment for diffusing (doping) impurities into the surface area of ​​a semiconductor wafer, an annealing equipment, or an etching equipment.

[0116] The semiconductor manufacturing equipment 2 disclosed herein may be an apparatus configured to process a substrate using plasma. [Simplified Explanation of the Diagram]

[0009] Figure 1 is a schematic diagram illustrating an example configuration of a heat treatment system; Figure 2 is a schematic cross-sectional view illustrating an example of a semiconductor manufacturing equipment; Figure 3 is a diagram illustrating an example of a partition; Figure 4 is a diagram illustrating an exemplary configuration of a controller; Figure 5 is a diagram illustrating an exemplary hardware configuration of a temperature correction information calculation device; Figure 6 is a functional block diagram illustrating an exemplary functional configuration of a temperature correction information calculation device; Figure 7 is an example of a temperature correction table; Figure 8 is a schematic diagram illustrating a model stored in a model memory; Figure 9 is a schematic diagram illustrating a temperature-to-power table and a cumulative film thickness-to-power table stored in a table memory; Figure 10 is a diagram illustrating an exemplary deposition result obtained by using a temperature correction table to correct the temperature based on the cumulative film thickness and performing a deposition process; Figure 11 is a flowchart illustrating an example of a process executed by a temperature correction information generation unit to generate a temperature correction table; Figure 12 is a diagram illustrating the role of heater power in updating the temperature correction table; Figure 13 is a schematic diagram illustrating a method for predicting heater power; Figure 14 is a diagram illustrating a method for calculating (i) the change in heater power caused by a change in the current temperature value; Figure 15 is a diagram illustrating a method for calculating (ii) the change in heater power caused by a change in the cumulative film thickness; Figure 16 is a flowchart illustrating an example of a process executed by a temperature correction information generation unit to generate a temperature correction table; and Figure 17 is a diagram illustrating the effect obtained by predicting heater power.

Claims

1. A temperature correction information calculation device for use with a semiconductor manufacturing apparatus, the semiconductor manufacturing apparatus being configured to correct a preset temperature based on an accumulated film thickness on an inner wall of one of the semiconductor manufacturing apparatuses, to control the temperature by using a heater to bring the temperature close to the corrected preset temperature, and to perform a deposition process on an object, the temperature correction information calculation device comprising: a storage unit configured to store a temperature correction value for correcting the preset temperature; an acquisition unit configured to acquire a first heater power applied to the heater, the first heater power being included in log information generated during the deposition process; a power prediction unit configured to predict a second heater power by adding a change in heater power caused by a change in the preset temperature and a change in heater power caused by a change in the accumulated film thickness to the first heater power; and a temperature correction information generation unit configured to correct the temperature correction value based on the second heater power predicted by the power prediction unit, wherein... The power prediction unit is configured to calculate the change in heater power caused by the change in cumulative film thickness by using a model and a cumulative film thickness-to-power table, in which temperature change is associated with film thickness change, and cumulative film thickness change is associated with heater power change in the cumulative film thickness-to-power table.

2. The temperature correction information calculation device as claimed in claim 1, wherein the power prediction unit is configured to calculate the change in heater power caused by the change in the preset temperature by using the temperature correction value and a temperature-to-power meter, wherein the temperature change in the temperature-to-power meter is associated with the change in heater power, and the temperature correction value is used in the deposition process and is associated with the cumulative film thickness.

3. The temperature correction information calculation device as claimed in claim 2, wherein the semiconductor manufacturing equipment includes a reaction tube divided into a plurality of regions, wherein the temperature-to-power meter has a column for heater power variation in each of the regions and a column for heater power variation in each of the regions, the temperature-to-power meter further includes a temperature correction table having a temperature correction value for each of the regions, and wherein the power prediction unit is configured to calculate the change in heater power caused by the preset temperature change for each of the regions by adding the values ​​obtained by multiplying the heater power variation in the column by the temperature correction value in the column of the temperature-to-power meter for each of the regions.

4. The temperature correction information calculation apparatus of claim 1, wherein the semiconductor manufacturing equipment includes a reaction tube divided into a plurality of regions, wherein the model has a film thickness variation for each of the regions, and the cumulative film thickness has a heater power variation for each of the regions, the heater power variation being associated with the cumulative film thickness, and wherein the power prediction unit is configured to calculate, for each of the regions, a heater power variation caused by the change in cumulative film thickness by multiplying the heater power variation for each of the regions by the film thickness variation.

5. The temperature correction information calculation device as claimed in any of claims 1 to 4, wherein the power prediction unit is configured to predict the power of the second heater based on each zone and on each cumulative film thickness.

6. A semiconductor manufacturing apparatus, comprising a temperature correction information calculation device as claimed in any one of claims 1 to 5.

7. A method for calculating temperature correction information using a semiconductor manufacturing apparatus configured to correct a preset temperature based on a cumulative film thickness on an inner wall of the semiconductor manufacturing apparatus, to control the temperature using a heater to bring the temperature close to the corrected preset temperature, and to perform a deposition process on an object, the method comprising: acquiring a first heater power applied to the heater, the first heater power being included in log information generated during the deposition process; predicting a second heater power by adding changes in heater power caused by a change in the preset temperature and changes in heater power caused by a change in the cumulative film thickness to the first heater power; and correcting a temperature correction value based on the predicted second heater power, the temperature correction value being stored in a memory, wherein... The change in heater power caused by the change in cumulative film thickness is calculated by using a model and a cumulative film thickness-to-power table, in which temperature change is associated with film thickness change, and cumulative film thickness change is associated with heater power change.

8. A program that causes a temperature correction information calculation device used with a semiconductor manufacturing apparatus to perform the following functions: the semiconductor manufacturing apparatus is configured to correct a preset temperature based on an accumulated film thickness on an inner wall of one of the semiconductor manufacturing apparatuses; control the temperature by using a heater to bring the temperature close to the corrected preset temperature; and perform a deposition process on an object, wherein the function comprises: an acquisition unit configured to acquire a first heater power applied to the heater, the first heater power being included in log information generated during the deposition process; a power prediction unit configured to predict a second heater power by adding a change in heater power caused by a change in the preset temperature and a change in heater power caused by a change in the accumulated film thickness to the first heater power; and a temperature correction information generation unit configured to correct a temperature correction value based on the second heater power predicted by the power prediction unit, the temperature correction value being stored in a memory, wherein... The power prediction unit is configured to calculate the change in heater power caused by the change in cumulative film thickness by using a model and a cumulative film thickness-to-power table, in which temperature change is associated with film thickness change, and cumulative film thickness change is associated with heater power change in the cumulative film thickness-to-power table.

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