TEMPERATURE CORRECTION INFORMATION CALCULATION DEVICE, SEMICONDUCTOR MANUFACTURING APPARATUS, PROGRAM, AND TEMPERATURE CORRECTION INFORMATION CALCULATION METHOD

Abstract

To provide a technology capable of adjusting a set temperature for heat processing on a body to be processed.SOLUTION: There is provided a temperature correction information calculation apparatus for a semiconductor manufacturing apparatus. The temperature correction information calculation apparatus executes film formation processing on a body to be processed by controlling a temperature using a heater so that the temperature becomes close to a set temperature corrected depending on an accumulated film thickness accumulated on an inner wall of the semiconductor manufacturing apparatus. The temperature correction information calculation apparatus includes: a storage unit for storing a temperature correction value for correcting the set temperature; an acquisition unit for acquiring first heater power applied to the heater, the first heater power being included in log information generated by the execution of the film formation processing; a power prediction unit for predicting second heater power by adding a variation in heater power caused by a change of the set temperature to the first heater power; and a temperature correction information generation unit for correcting the temperature correction value using the second heater power predicted by the power prediction unit.SELECTED DRAWING: Figure 13

Description

[Technical field]

[0001] The present disclosure relates to a temperature correction information calculation device, a semiconductor manufacturing device, a program, and a temperature correction information calculation method. [Background technology]

[0002] In the semiconductor manufacturing process, for example, a heat treatment system is used to perform a film formation process on a semiconductor wafer. In the heat treatment system, the process conditions controlled by the semiconductor manufacturing equipment, such as the set temperature, pressure, and gas flow rate, are determined by a process recipe corresponding to the process. When the semiconductor manufacturing equipment repeats heat treatment, for example, a film is formed on the semiconductor wafer, but deposits adhere to the inner wall surface of the semiconductor manufacturing equipment. When the accumulated thickness of the deposits becomes thick, the temperature inside the furnace drops, and it becomes impossible to form a film with a desired thickness on the semiconductor wafer, even if the semiconductor manufacturing equipment is controlled at a set temperature according to the process recipe.

[0003] Therefore, a heat treatment system that corrects the set temperature in accordance with the accumulated film thickness is known (see, for example, Patent Document 1). Patent Document 1 discloses a technique for generating temperature correction information in which the accumulated film thickness is associated with a correction amount for the set temperature. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-218558 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a technique capable of adjusting a set temperature for heat treatment of a workpiece. [Means for solving the problem]

[0006] The present disclosure relates to a temperature correction information calculation device for a semiconductor manufacturing apparatus that controls a temperature using a heater so as to approach a set temperature corrected according to a cumulative film thickness accumulated on an inner wall of the semiconductor manufacturing apparatus, and executes a film formation process on a processing object, the device having a storage unit that stores a temperature correction value for correcting the set temperature, an acquisition unit that acquires a first heater power applied to the heater included in log information generated by execution of the film formation process, a power prediction unit that predicts a second heater power by adding an amount of fluctuation in heater power due to a change in the set temperature to the first heater power, and a temperature correction information generation unit that corrects the temperature correction value using the second heater power predicted by the power prediction unit, The power prediction unit calculates the amount of heater power fluctuation due to a change in the accumulated film thickness using a model in which the amount of temperature fluctuation corresponds to the amount of film thickness fluctuation, and a cumulative film thickness power table in which the amount of cumulative film thickness fluctuation corresponds to the amount of heater power fluctuation, and predicts the second heater power by adding the amount of heater power fluctuation due to a change in the accumulated film thickness to the first heater power. Effect of the Invention

[0007] It is possible to provide a technique for adjusting the set temperature of the heat treatment for the object to be treated. [Brief description of the drawings]

[0008] [Figure 1] An example of a schematic diagram of a heat treatment system [Diagram 2] An example of a schematic cross-sectional view of semiconductor manufacturing equipment [Diagram 3] An example of a divided zone [Figure 4] An example of the control unit configuration [Diagram 5] An example of a hardware configuration diagram of a temperature correction information calculation device [Figure 6] FIG. 1 is a functional block diagram illustrating a functional configuration of a temperature correction information calculation device, divided into blocks. [Figure 7] An example of a temperature correction table [Figure 8] FIG. 1 is a diagram for explaining a model stored in a model storage unit; [Figure 9] FIG. 1 is a diagram for explaining a temperature power table and a cumulative film thickness power table stored in a table storage unit; [Figure 10] An example of the film formation result when the temperature correction table is used to perform temperature correction according to the accumulated film thickness. [Figure 11] FIG. 1 is an example of a flowchart illustrating a procedure for a temperature correction information generating unit to derive a temperature correction table. [Figure 12] An example of a diagram explaining the role of heater power in updating the temperature correction table [Figure 13] An example of a diagram for explaining a method for predicting heater power [Figure 14] (i) An example of a diagram illustrating a method for calculating the amount of heater power fluctuation due to a change in temperature setting value [Figure 15] (ii) An example of a diagram illustrating a method for calculating the amount of heater power fluctuation due to a change in cumulative film thickness [Figure 16] FIG. 1 is an example of a flowchart illustrating a procedure for a temperature correction information generating unit to derive a temperature correction table. [Figure 17] An example of a diagram explaining the effect of heater power prediction DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. As an example of an embodiment for carrying out the present invention, a heat treatment system and a temperature correction information calculation method performed by the heat treatment system will be described with reference to the drawings.

[0010] [Summary of temperature correction for cumulative film thickness] The heat treatment system performs multiple film formation processes in one cycle. In addition, in the film formation processes, the heat treatment system corrects the set temperature set in the process recipe using a temperature correction table. When generating the temperature correction table, the heater power recorded in the log is taken into consideration. However, since the heater power taken into consideration is based on the log obtained in any film formation process in one cycle (which can be selected by the user, but the log of the first film formation process is usually selected), there is a possibility that the heater power in the second or subsequent film formation processes will be different from the heater power in the first film formation process. If the temperature during film formation is corrected using a temperature correction table that has been corrected using a heater power different from the actual heater power, there is a risk that the target film thickness, etc. will not be obtained.

[0011] Therefore, the heat treatment system of this embodiment predicts the heater power for the second and subsequent times in a cycle from the first (initial) heater power, thereby more appropriately correcting the temperature correction table and making it possible to obtain a film thickness, etc. that is close to the target.

[0012] Details are explained below.

[0013] [Overall configuration of a heat treatment system including semiconductor manufacturing equipment] FIG. 1 is a schematic diagram showing an example of a heat treatment system. As shown in FIG. 1, the heat treatment system 1 according to the present embodiment includes a plurality of semiconductor manufacturing apparatuses 2 (two 1 1 to 2n), a host computer 3, a temperature correction information calculation device 4, and networks 5 and 6 which interconnect these. The heat treatment system 1 also includes a measurement device 60 which measures the state (such as the state of the film) of a target object (hereinafter referred to as a semiconductor wafer) processed by the semiconductor manufacturing apparatus 2.

[0014] The semiconductor manufacturing equipment 2 may include various types of equipment according to the process. For example, there are film forming equipment that performs a process of forming a thin film on a semiconductor wafer, an oxidation equipment that performs an oxidation process of oxidizing the surface region of a semiconductor wafer, and a diffusion equipment that performs a process of diffusing (doping) impurities into the surface region of a semiconductor wafer. Below, as an example of a semiconductor manufacturing equipment, a batch-type vertical heat treatment equipment shown in FIG. 2 will be described. In addition, in this embodiment, a film forming process will be described as an example of the process on a semiconductor wafer.

[0015] Fig. 2 is an example of a schematic cross-sectional view of the semiconductor manufacturing apparatus 2. As shown in Fig. 2, the semiconductor manufacturing apparatus 2 includes a substantially cylindrical reaction tube 11. The reaction tube 11 is arranged so that its longitudinal direction faces the vertical direction. The reaction tube 11 is made of a material having excellent heat resistance and corrosion resistance, such as quartz.

[0016] An exhaust pipe 12 for exhausting gas inside the reaction tube 11 is airtightly connected to the upper side of the reaction tube 11. The exhaust pipe 12 is provided with a pressure adjusting unit 13 consisting of a valve, a vacuum pump, etc., and adjusts the pressure (degree of vacuum) inside the reaction tube 11 to a desired level.

[0017] A substantially cylindrical manifold 14 is provided below the reaction tube 11. The upper end of the manifold 14 is airtightly joined to the lower end of the reaction tube 11.

[0018] A lid body 15 is disposed below the manifold 14 (reaction tube 11). The lid body 15 is configured to be movable up and down by a boat elevator 16, and is disposed so that when the lid body 15 is raised by the boat elevator 16, the lower side (furnace opening portion) of the manifold 14 (reaction tube 11) is closed, and when the lid body 15 is lowered by the boat elevator 16, the lower side (furnace opening portion) of the reaction tube 11 is opened.

[0019] A wafer boat 18 is provided on the top of the lid 15 via a heat retaining cylinder (thermal insulator) 17. The wafer boat 18 is a wafer holder that accommodates (holds) objects to be processed, such as semiconductor wafers W, and in this embodiment, is configured to accommodate a plurality of semiconductor wafers W, for example, 150 semiconductor wafers W, spaced at predetermined intervals in the vertical direction. The semiconductor wafers W are then accommodated in the wafer boat 18, and the lid 15 is raised by the boat elevator 16, whereby the semiconductor wafers W are loaded into the reaction tube 11.

[0020] A heater section 19 made of, for example, a resistance heating element is provided around the reaction tube 11 so as to surround the reaction tube 11. The heater section 19 heats the inside of the reaction tube 11 to a predetermined temperature, and as a result, the semiconductor wafer W is heated to the predetermined temperature.

[0021] The heater section 19 has heaters 191-195 arranged in, for example, five stages, and each of the heaters 191-195 is independently supplied with power by power controllers 196-200, and can be independently controlled. In this manner, the inside of the reaction tube 11 is divided into five zones (ZONE 1-5) by the heaters 191-195 as shown in Fig. 3. The number of zones is not limited to five, and may be two or more, or may not be divided into zones.

[0022] Further, the manifold 14 is provided with a plurality of gas supply pipes for supplying gas into the reaction tube 11. In the present embodiment, three gas supply pipes 20 to 22 are provided. A source gas and a carrier gas for film formation are supplied to each of the gas supply pipes 20 to 22 via flow rate adjustment units 23 to 25 each including a mass flow controller (MFC) or the like for adjusting the gas flow rate.

[0023] Five temperature sensors (thermocouples) (not shown) are arranged in a vertical row on the inner wall of the reaction tube 11. These temperature sensors are covered with a quartz pipe or the like to prevent metal contamination of the semiconductor wafers W, and are arranged in each zone shown in FIG.

[0024] The semiconductor manufacturing equipment 2 includes a control unit 50 for controlling process parameters such as the temperature, gas flow rate, and pressure of the process atmosphere in the reaction tube 11. The control unit 50 receives output signals from a temperature sensor, a pressure sensor, etc. (not shown), and outputs control signals to power controllers 196-200 for heaters 191-195, the pressure adjustment unit 13, and the flow rate adjustment units 23-25.

[0025] [Example of hardware configuration of the control unit] 4 is a diagram showing an example of the configuration of the control unit 50. The control unit 50 includes a recipe storage unit 51, a ROM 52, a RAM 53, an I / O port 54, a CPU 55, a communication unit 56, and a bus 57 connecting these units to each other.

[0026] The recipe storage unit 51 stores a process recipe that determines a control procedure according to the type of film formation process performed by the semiconductor manufacturing apparatus 2. The process recipe is processing information prepared for each process actually performed by an operator, and specifies the temperature change of each part, the pressure change in the reaction tube 11, the timing and amount of gas supply start and stop, and the like, from the loading of the semiconductor wafer W into the reaction tube 11 to the unloading of the processed semiconductor wafer W. This process recipe can specify the set film thickness by the heat treatment and the set temperature of each part of the apparatus. In the case of a normal batch-type heat treatment apparatus, one process recipe is prepared for all semiconductor wafers W, but in this embodiment, a predetermined process recipe is prepared for each zone shown in FIG. 3 so that the processing result of the semiconductor wafer W is uniform.

[0027] This process recipe also includes an optimization value calculation recipe that corrects the set temperature of each part of the equipment to an optimal temperature (optimized value) based on a temperature correction table and sets the corrected temperature as the set temperature. Therefore, when the semiconductor manufacturing equipment 2 performs heat treatment based on the optimization value calculation recipe, the optimized values ​​of the set temperatures of zones 1 to 5 are calculated, and the optimized values ​​become the set temperatures.

[0028] Therefore, the set temperature is corrected by the semiconductor manufacturing equipment 2, but the temperature correction information calculation device 4 may provide the semiconductor manufacturing equipment 2 with a process recipe in which the set temperature has been corrected based on a temperature correction table. Alternatively, any device may correct the set temperature, as long as the semiconductor manufacturing equipment 2 can ultimately execute the process recipe at the corrected set temperature.

[0029] The ROM 52 is composed of an EEPROM, a flash memory, a hard disk, etc., and is a recording medium that stores the operating program of the CPU 55 and the like.

[0030] The RAM 53 functions as a work area for the CPU 55. The RAM 53 stores, for example, the number of times a process is executed in the semiconductor manufacturing equipment 2. The cumulative film thickness of the deposit adhering to the inside of the semiconductor manufacturing equipment 2 can be specified based on the number of times the process is executed and the set film thickness stored in the recipe storage unit 51.

[0031] The I / O port 54 supplies measurement signals relating to temperature, pressure, and gas flow rate to the CPU 55, and also outputs control signals output by the CPU 55 to each unit (power controllers 196-200, flow rate adjustment units 23-25, and pressure adjustment unit 13). In addition, an operation panel 58 through which an operator operates the semiconductor manufacturing equipment 2 is connected to the I / O port 54.

[0032] The CPU 55 constitutes the core of the control unit 50, executes the operating program stored in the ROM 52, and controls the operation of the semiconductor manufacturing equipment 2 in accordance with the process recipe stored in the recipe memory unit 51 in response to instructions from the operation panel 58.

[0033] A communication unit 56 performs communication between the semiconductor manufacturing equipment 2, the host computer 3, and the temperature correction information calculation device 4 via the LANs 5 and 6. A bus 57 transfers information between each unit.

[0034] The host computer 3 is a device that controls the entire semiconductor manufacturing equipment 2, and executes processes to instruct each semiconductor manufacturing equipment 2 to perform heat treatment, etc. The host computer 3 has a known configuration and is not shown in the figure.

[0035] [Hardware configuration example of temperature correction information calculation device] 5 shows an example of a hardware configuration diagram of a temperature correction information calculation device. The temperature correction information calculation device 4 executes a process of generating a temperature correction table according to the accumulated film thickness (number of film formations) in order to reduce the difference between the furnace temperature and the set temperature caused by the accumulated film thickness in each of the semiconductor manufacturing devices 2.

[0036] The temperature correction information calculation device 4 has a CPU (Central Processing Unit) 501, a ROM (Read Only Memory) 502, and a RAM (Random Access Memory) 503. The CPU 501, the ROM 502, and the RAM 503 form a so-called computer. The temperature correction information calculation device also has an auxiliary storage device 504, an operation device 505, a display device 506, an I / F (Interface) device 507, and a drive device 508. The hardware components of the temperature correction information calculation device 4 are connected to each other via a bus 509.

[0037] The CPU 501 executes various programs installed in the auxiliary storage device 504 .

[0038] The ROM 502 is a non-volatile memory and functions as a main storage device. The ROM 502 stores various programs and data necessary for the CPU 501 to execute various programs installed in the auxiliary storage device 504.

[0039] The RAM 503 is a volatile memory such as a dynamic random access memory (DRAM) or a static random access memory (SRAM), and functions as a main storage device. The RAM 503 provides a working area in which various programs installed in the auxiliary storage device 504 are expanded when the CPU 501 executes them.

[0040] The auxiliary storage device 504 is a non-volatile large-capacity storage device that stores various programs. The auxiliary storage device 504 may be a non-volatile large-capacity storage medium such as a hard disk drive (HDD) or a solid state drive (SSD).

[0041] The operation device 505 is an input device used when an administrator inputs various instructions to 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 acquired from the outside.

[0042] The I / F device 507 is a connection device that connects to the LAN 6 and communicates with the control unit 50 of the semiconductor manufacturing equipment 2. The I / F device 507 also communicates with the measuring equipment 60 and the host computer 3.

[0043] The drive device 508 is a device for setting a recording medium. The recording medium includes media that record information optically, electrically, or magnetically, such as a CD-ROM, a flexible disk, a magneto-optical disk, etc. The recording medium may also include semiconductor memories that record information electrically, such as ROMs, flash memories, etc.

[0044] The various programs to be installed in the auxiliary storage device 504 are installed, for example, by setting a distributed recording medium in the drive device 508 and reading out the various programs recorded on the recording medium by the drive device 508. Alternatively, the various programs to be installed in the auxiliary storage device 504 may be installed by downloading them from a predetermined server.

[0045] [Functions of the temperature correction information calculation device] Next, the information and the functional configuration of the temperature correction information calculation device 4 will be described with reference to Fig. 6. Fig. 6 is an example of a functional block diagram explaining the functional configuration of the temperature correction information calculation device 4 by dividing it into blocks.

[0046] The temperature correction information calculation device 4 has an acquisition unit 61, a temperature correction information generation unit 62, a model learning unit 63, and a power prediction unit 64. These functions of the temperature correction information calculation device 4 are functions or means realized by the CPU 501 shown in FIG. 5 executing a program expanded from the auxiliary storage device 504 to the RAM 503.

[0047] The acquiring unit 61 acquires log information relating to the heat treatment process of the semiconductor wafer W executed based on the process recipe from the control unit 50 of the semiconductor manufacturing equipment 2. The log information includes the set temperature, heater power, etc. in chronological order. The acquiring unit 61 acquires the heater power applied to the heater included in the log information generated by the execution of the film formation process. The acquiring unit 61 can also acquire the monitored film thickness of the semiconductor wafer W monitored by the measuring device 60. Since the log information indicates the number of times the process has been executed in the semiconductor manufacturing equipment 2, the accumulated film thickness of the deposits adhering to the inside of the semiconductor manufacturing equipment 2 can be identified based on the number of times the process has been executed and the set film thickness stored in the process recipe.

[0048] The temperature correction information generating unit 62 generates a temperature correction table by using a model, which will be described later, for the relationship between the set temperature included in the log information and the monitored film thickness measured by the measuring device 60. In addition, the temperature correction information generating unit 62 corrects the temperature correction value of the temperature correction table so that the heater power does not become saturated (0 or 100%).

[0049] The model learning unit 63 updates the model stored in the model storage unit 72. Updating the model means changing the model to one that more accurately represents the relationship between the set temperature and film thickness in the semiconductor manufacturing equipment 2, based on the film formation result and the target film thickness. In this sense, updating can be called learning, and may also be called learning in this embodiment. Since model learning is not a characteristic feature of this embodiment, details will be omitted.

[0050] The power prediction unit 64 predicts the heater power for the second and subsequent film formation processes from the heater power recorded in the log information for the first film formation process in one cycle. The first film formation process in one cycle is selected by many users, and the log does not have to be that obtained from the first film formation process in one cycle. A temperature power table and a temperature correction table are used for the prediction. Furthermore, a cumulative film thickness power table and a fluctuation amount of the cumulative film thickness may be used for the prediction.

[0051] Furthermore, the temperature correction information calculation device 4 has a storage unit 70 formed in the RAM 503 or the auxiliary storage device 504. The storage unit 70 has a temperature correction table storage unit 71, a model storage unit 72, and a table storage unit 73.

[0052] Fig. 7 is an example of a temperature correction table. The temperature correction table shows the relationship between the cumulative film thickness of the deposit inside the semiconductor manufacturing equipment 2 and the temperature correction amount for each temperature (set temperature) inside the equipment. In the temperature correction table of Fig. 7, the temperature inside the semiconductor manufacturing equipment 2 is set to a predetermined temperature, and the temperature correction value when the deposit of a predetermined cumulative film thickness has adhered inside the equipment is associated with each zone.

[0053] In the example of FIG. 7, a film thickness of tk1 [nm] is formed on a semiconductor wafer in the initial state before the process recipe is executed. tk1 is, for example, 100 [nm], but varies depending on the process recipe. The process recipe includes six film formation processes. These six film formation processes constitute one cycle of heat treatment. A film is formed with a predetermined film thickness Δtk in one film formation process. The cumulative film thickness increases as tk2=tk1+Δtk, tk3=tk2+Δtk, …, and a film thickness of tk6+Δtk is obtained in the sixth process. Note that one cycle of heat treatment can include any number of film formation processes, and the film thickness formed in one film formation process varies depending on the process recipe.

[0054] When the semiconductor manufacturing equipment 2 corrects the set temperature of the zone 1, for example, when the accumulated film thickness is tk2 [nm], the corrected set temperature is calculated as "set temperature of the process recipe + 0.1" °C.

[0055] If the set temperature and accumulated film thickness differ from the values ​​defined in the temperature correction table, the semiconductor manufacturing equipment 2 can make an interpolation to accommodate the difference.

[0056] The temperature correction table is an example of information that stores temperature correction values ​​for correcting the set temperature, and the storage format of the temperature correction values ​​is not limited to a table or tabular format. For example, the temperature correction table may be in a functional format or a graph format.

[0057] Fig. 8 is a diagram for explaining the models stored in the model storage unit 72. A model is prepared for each set temperature, but Fig. 8 shows a model for an arbitrary set temperature. The model is data used to control the semiconductor manufacturing equipment 2, which is obtained by investigating the relationship between the set temperature and the change in power in advance.

[0058] The model in FIG. 8(a) represents the temperature fluctuation amount of each slot when the temperature of each zone is increased by +1°C. In other words, when the temperature of one zone is changed, the temperature of the other zones also changes. In this way, the temperature of the semiconductor wafer may not be completely the same as the set temperature due to the temperature distribution of the reaction tube 11, etc. Using the model in FIG. 8(a), the actual temperature of the semiconductor wafer W when the set temperature differs by 1°C is calculated for each zone.

[0059] In the model of FIG. 8(b), the amount of film thickness variation when the temperature differs by 1°C is determined for each zone. In other words, the amount of temperature variation and the amount of film thickness variation are associated. A film is formed on the semiconductor wafer W to a thickness that corresponds to the actual temperature of the semiconductor wafer W during heat treatment (assuming other parameters such as gas type and pressure are constant) and the heat treatment time. The model of FIG. 8(b) represents the correspondence between the temperature of the actual semiconductor wafer W and the film thickness according to various findings. For example, in zone 1, the amount of film thickness variation when the temperature differs by 1°C (this temperature has been corrected in FIG. 8(a)) is K [nm].

[0060] An example of generating a temperature correction table for zone 1 using the model in Fig. 8(b) will be described below. For example, the following evaluation function is used to generate the temperature correction table.

[0061] Evaluation function J = f (residual from target film thickness, model showing temperature and film thickness fluctuation, temperature fluctuation) The model expressing the amount of fluctuation in temperature and film thickness is a model of "set temperature vs. wafer temperature" that combines the model of "set temperature vs. wafer temperature" in Fig. 8(a) and the model of "wafer temperature vs. amount of film deposition" in Fig. 8(b) into a model of "set temperature vs. amount of film deposition." Based on this, the heater power is not saturated and does not exceed the temperature constraint range specified by the user, and the combination of temperature fluctuation amounts that minimizes the evaluation function J within the constraint range is set as the optimal value.

[0062] Therefore, since the two models in Fig. 8 are referred to when generating the temperature correction table, it is desirable that they are as accurate as possible. For this reason, the temperature correction information calculation device 4 has a function of learning the model. The model learning unit 63 updates (learns) the model based on the difference between the monitor film thickness and the target film thickness. The idea is that the greater the difference between the monitor film thickness, which is the film formation result, and the target film thickness, the greater the amount of variation in temperature of the semiconductor wafer W when the temperature differs by 1°C in the model in Fig. 8(a), and the greater the amount of variation in film thickness when the temperature differs by 1°C in the model in Fig. 8(b).

[0063] More specifically, the model learning unit 63 updates the two models by applying the difference between the monitor film thickness and the target film thickness to an extended Kalman filter or the like. The method of updating the models is not a feature of the present application, so details will be omitted. In the following, unless otherwise stated, the models include the two models in FIG. 8.

[0064] The model is an example of information storing the amount of temperature fluctuation of the semiconductor wafer W relative to the amount of fluctuation in the set temperature, or the amount of film thickness fluctuation relative to the amount of fluctuation in the set temperature, and the storage format of this information is not limited to a table or tabular format. For example, the model may be in a functional format or a graph format.

[0065] FIG. 9(a) shows an example of a temperature power table stored in the table storage unit 73. The temperature power table is also one of the models. The temperature power table is a table for calculating the amount of power fluctuation due to a change in the set temperature. As shown in FIG. 9(a), the amount of heater power fluctuation required for each zone to change the temperature of the zone by 1°C is set. In other words, the amount of temperature fluctuation and the amount of heater power fluctuation are associated with each other. The actual values ​​vary, but as an example, they are percentages (%) on the order of one thousandth to one tenth.

[0066] FIG. 9(b) shows an example of the accumulated film thickness power table stored in the table storage unit 73. The accumulated film thickness power table is a table for calculating the amount of change in heater power due to a change in accumulated film thickness. The accumulated film thickness power table in FIG. 9(b) shows the amount of change in power due to a change in heat transfer caused by an increase in the accumulated film thickness on the chamber wall surface. That is, the amount of change in accumulated film thickness and the amount of change in heater power are associated with each other. As the accumulated film thickness increases, the amount of change in heater power tends to saturate, so the output value of the heater power also shows a similar tendency. That is, the slope of the amount of change in heater power also changes depending on the accumulated film thickness. Details of how to use it will be described later. Note that the values ​​in FIG. 9(b) are merely an example for explanation.

[0067] The temperature power table and the cumulative film thickness power table are examples of information that stores the amount of change in heater power, and the storage format of this information is not limited to a table or tabular format. For example, the temperature power table and the cumulative film thickness power table may be in a function format or a graph format.

[0068] [Outline of temperature compensation function according to accumulated film thickness] FIG. 10 is a diagram for explaining an example of a film formation result in the case where a film formation process is performed by performing temperature correction according to the accumulated film thickness using the temperature correction table.

[0069] (1) First, heat treatment is performed by the semiconductor manufacturing equipment 2 using the temperature correction table before correction. In Figure 10, this corresponds to the heat treatment "before temperature correction." The heat treatment "before temperature correction" is called the first heat treatment (it includes six film formation processes). The film thickness formed in one film formation process is Δtk [nm]. As shown in Figure 10(a), each film formation process aims to form a film of Δtk [nm] on the wafer W, but the cumulative film thickness deposited on the chamber wall surface results in a deviation from the target Δtk [nm]. Figure 10(a) shows the film formation result obtained in the film formation process of the first heat treatment.

[0070] In FIG. 10(a), the horizontal axis is the accumulated film thickness and the vertical axis is the monitor film thickness. The monitor film thickness varies around Δtk. In FIG. 10(a), one cycle of film formation includes six film formation processes. The monitor film thickness formed in one film formation process is shown against the accumulated film thickness accumulated in six film formation processes. Also, the multiple graphs in FIG. 10(a) are the monitor film thicknesses of semiconductor wafers W at different vertical positions in the wafer boat 18. That is, since the gas concentration differs depending on the height in the reaction tube 11, semiconductor wafers W at different heights are extracted in advance for monitoring. The semiconductor wafers W for which the monitor film thickness is measured are semiconductor wafers W representative of each zone.

[0071] As the number of film formation processes increases, the accumulated film thickness on the inner wall surface of the semiconductor manufacturing equipment also increases. If the accumulated film thickness becomes thicker, the temperature inside the furnace will drop even if the same processing temperature is used, making it impossible to form a thin film of the desired thickness on the semiconductor wafer W. In Figure 10(a), the monitored film thickness before temperature correction tends to gradually increase as the accumulated film thickness increases.

[0072] (2) The temperature correction information generating unit 62 generates the temperature correction table shown in FIG. 10(b) by using the model of FIG. 8 for the relationship between the set temperature included in the log information and the monitored film thickness obtained from the measuring device 60. The generation of the temperature correction table immediately after the first heat treatment is called the first calculation process. In FIG. 10, the process corresponding to "calculation" is the generation of the temperature correction table. In the second and subsequent calculations after the temperature correction table is generated, the model may be updated by user setting or automatic judgment. Automatic judgment means, for example, that if the result is not improved even when the temperature correction table calculated in the first calculation is used, the model is judged to be poor in accuracy, and the model is updated in the second and subsequent calculations to generate a temperature correction table that is closer to the target. In addition, the model may be automatically updated by detecting disturbances, etc.

[0073] In addition, since model updating (learning) is performed using past calculation data, there is no past calculation data in the first heat treatment, and therefore model updating is not performed in the first calculation process.

[0074] (3) Heat treatment is performed by the semiconductor manufacturing equipment 2 using the temperature correction table. FIG. 10 corresponds to the heat treatment "after temperature correction." FIG. 10(c) shows the film formation result obtained in the film formation process in which the set temperature was corrected using the temperature correction table. FIG. 10(c) shows a tendency for the monitored film thickness to be stable due to temperature correction, even if the accumulated film thickness becomes thick.

[0075] [Generation of temperature correction table] FIG. 11 is an example of a flowchart illustrating a procedure in which the temperature correction information generating unit 62 derives the temperature correction table.

[0076] First, before the film formation, a person in charge creates a process recipe (settings such as temperature setpoints) for performing the film formation (S1). At this time, the temperature correction table is before optimization, so any value can be set by the user. Instead of the person in charge setting the values, the temperature correction information generating unit 62 may set a predetermined initial value.

[0077] Using the process recipe and temperature correction table created in step S1, the semiconductor manufacturing equipment 2 performs one cycle of film formation (maximum 20 film formations) (S2).

[0078] The measuring device 60 measures the thickness of the film formed in each film forming process for one cycle (S3). At this time, if the repeatability of the film thickness during one cycle meets a desired standard, the adjustment of the temperature correction table is completed. If the standard is not met, the process proceeds to step S4.

[0079] The temperature correction information generating unit 62 optimizes the temperature correction table using the log of any film formation result (selected by the user) performed in step S2, the process result measured in step S3, and the temperature correction table values ​​and model used in the film formation process (S4). Furthermore, in step S4, the temperature correction information generating unit 62 corrects the temperature correction table based on the heater power and the "model of power fluctuation amount for a temperature change of 1°C (temperature power table)" so that the temperature correction table can be realized within a range where the heater power is not saturated. Details will be described in FIG. 12.

[0080] The temperature correction information generating unit 62 updates the set values ​​in the temperature correction table with the values ​​optimized in step S4 (S5).

[0081] The temperature correction information calculation device 4 repeats the film formation process, optimization calculation, and update of the temperature correction table in the above steps S2 to S5 until a desired film thickness reproducibility is satisfied.

[0082] [Problems caused by heater power saturation] The role of the heater power in correcting the temperature correction table and the inconvenience of correcting the temperature correction table using the heater power selected by the user in step S2 will be described.

[0083] Fig. 12 is a diagram explaining the role of heater power in updating the temperature correction table. When the semiconductor manufacturing equipment 2 performs a film formation process as in step S2 in Fig. 11, a log of the power output state (heater power) in the film formation process and the like is left (Fig. 12(a)). In a comparative example (e.g., prior art) method, the user selects the log of the first film formation process in one cycle and inputs it to the temperature correction information calculation device 4 (software). The heater power for the remaining film formation processes in one cycle is assumed to be the same as the heater power in the selected log.

[0084] When calculating in step S4 in Fig. 11, the temperature correction information generating unit 62 determines how much the heater power can be varied above and below the heater power value in the log. For example, if the heater power in the log is 10%, then there is a margin of 0.1% at the lower limit and 99.9% at the upper limit (Fig. 12(b)). The 0.1% above and below is an offset.

[0085] Next, the temperature correction information generating unit 62 combines the determined "power fluctuation range" with the "model of power fluctuation amount for a 1°C change in temperature (temperature power table)" to determine the range of the temperature setting value that can be varied (FIG. 12(c)). If the power value read from the log is 100%, the temperature correction information generating unit 62 always fluctuates the temperature in the direction that decreases the heater power, and conversely, if the heater power is 0%, the temperature always fluctuates in the direction that increases the power. In other words, the temperature correction information generating unit 62 corrects the temperature correction table using the heater power predicted by the power predicting unit 64. In this way, if the heater power is saturated, the temperature is only fluctuated in one direction.

[0086] However, if the heater power is assumed to be the same for all film formation processes in one cycle as in the comparative technique, the following inconveniences arise.

[0087] The log power of the selected film formation process was "1%" -> the power of all other film formation processes in one cycle is also assumed to be "1%" -> the heater power will not saturate even if the power is increased or decreased within the range of "-0.9 to 98.9%" for all film formation processes in one cycle -> however, if the heater power of film formation processes other than the selected film formation process is actually "0.5%", there is a possibility that it will be moved to "-0.9%" even though the lower limit can only be moved to "-0.4%" -> if a film formation process is performed using a correction value that moves the heater power to "-0.9%", the heater power will saturate in the film formation process where the heater power was "0.5%", and no improvement effect will be seen.

[0088] For this reason, in this embodiment, the temperature correction information generating unit 62 predicts the heater power for each film forming process and generates a temperature correction table.

[0089] Although the user may select the logs of all the film formation processes in one cycle, this reduces usability.The temperature correction information generating unit 62 can also automatically select the logs of all the film formation processes in one cycle, but there is a possibility that the software may make an incorrect selection, and the user may need to check (and possibly correct) the logs for one cycle that were automatically selected after the process log selection.

[0090] [Heater power prediction] 13 is a diagram for explaining a method for predicting heater power. The power prediction unit 64 predicts the heater power (Pwn, n=2...maximum 20, an example of the second heater power) of the next film formation process based on the heater power (Pw0, an example of the first heater power) of the film formation process log selected by the user in one cycle (e.g., the log of the first film formation process).

[0091] Pwn = Pw0 + (i) Heater power fluctuation due to change in temperature setting + (ii) Heater power fluctuation due to change in cumulative film thickness ……(1) The calculation of (i) is based on the temperature power table and the temperature correction table used in the film formation process, and the calculation of (ii) is based on the cumulative film thickness power table and the amount of change in the cumulative film thickness.

[0092] Fig. 14 is a diagram explaining (i) a method for calculating the amount of heater power fluctuation due to a change in the temperature set value. Fig. 14(a) shows a temperature power table, and Fig. 14(b) shows a temperature correction table. The amount of heater power fluctuation is calculated for each corresponding zone by multiplying the heater power for one column of the temperature power table by the temperature correction value in the temperature correction table. For example, for zone 4 when the cumulative film thickness is 100 [nm], one column of zone 4 in the temperature power table is multiplied by the temperature correction value for zone 4 in the temperature correction table.

[0093] D1×0.2, D2×0.2, D3×0.2, D4×0.2, D5×0.2 The temperature correction values ​​for zones 1 to 3 and zone 5 are calculated in the same manner. Next, the power prediction unit 64 adds the multiplied values ​​in the row direction of the temperature-power table to calculate the amount of fluctuation in the heater power for each zone. For example, the amount of fluctuation in the heater power for zones 1 to 5 is as follows:

[0094] (i) Fluctuation in heater power due to change in temperature setpoint (Zone 1) = A1 x 0.1 + B1 x (-0.3) + C1 x (0.0) + D1 x 0.2 + E1 x (-0.1) (i) Fluctuation in heater power due to change in temperature setpoint (Zone 2) = A2 x 0.1 + B2 x (-0.3) + C2 x (0.0) + D2 x 0.2 + E2 x (-0.1) (i) Fluctuation in heater power due to change in temperature setpoint (Zone 3) = A3 x 0.1 + B3 x (-0.3) + C3 x (0.0) + D3 x 0.2 + E3 x (-0.1) (i) Fluctuation in heater power due to change in temperature setpoint (Zone 4) = A4 x 0.1 + B4 x (-0.3) + C4 x (0.0) + D4 x 0.2 + E4 x (-0.1) (i) Fluctuation in heater power due to change in temperature setpoint (Zone 5) = A5 x 0.1 + B5 x (-0.3) + C5 x (0.0) + D5 x 0.2 + E5 x (-0.1) The temperature correction table I used in the calculation of (i) is the temperature correction table used when the film formation process is performed, that is, the temperature correction table I is the temperature correction table before the optimization calculation is performed.

[0095] On the other hand, an optimized temperature correction table II is obtained from the temperature correction table I used in the calculation of (i), the film formation result, the heater power obtained from the log during the film formation, etc. The optimized temperature correction table II becomes the temperature correction table to be used for the film formation process of the next cycle.

[0096] That is, the power prediction unit 64 predicts the heater power using the old temperature correction table I, and the temperature correction information generation unit 62 generates a new temperature correction table II.

[0097] Fig. 15 is a diagram for explaining (ii) a method for calculating the amount of heater power fluctuation due to a change in accumulated film thickness. Fig. 15(a) shows an accumulated film thickness power table, and Fig. 15(b) shows the amount of film thickness fluctuation (the same as Fig. 8(b)) when the temperature differs by 1°C. The amount of heater power fluctuation is calculated for each zone by multiplying the value in Fig. 15(a) by the value in Fig. 15(b). For example, when the accumulated film thickness is 100 [nm], the amount of heater power fluctuation for zones 1 to 5 is calculated as follows:

[0098] (ii) Fluctuation in heater power due to change in cumulative film thickness in zone 1 = 0.03 x K (ii) Fluctuation in heater power due to change in cumulative film thickness in zone 2 = 0.03 × L (ii) Fluctuation in heater power due to change in cumulative film thickness in zone 3 = 0.02 × M (ii) Fluctuation in heater power due to change in cumulative film thickness in zone 4 = 0.02 × N (ii) Fluctuation in heater power due to change in cumulative film thickness in zone 5 = 0.03 × O In Fig. 15, the amount of power fluctuation according to the accumulated film thickness is multiplied by the amount of film thickness fluctuation according to temperature, but more precisely, "(ii) amount of heater power fluctuation due to changes in accumulated film thickness" is thought to tend to saturate as the accumulated film thickness increases. Therefore, it is advisable to obtain a relationship in advance so that "amount of power fluctuation = f (accumulated film thickness)" and then use that relationship to interpolate to find the amount of power fluctuation for the accumulated film thickness you want to predict.

[0099] In addition, the amount of change in film thickness when the temperature differs by 1°C in Fig. 15(b) may be used depending on the cumulative film thickness. Also, the term (ii) in equation (1) has little effect on the heater power, so it does not necessarily have to be used to predict the heater power.

[0100] [Operation procedure] Fig. 16 is an example of a flowchart illustrating a procedure for deriving a temperature correction table by the temperature correction information generating unit 62. Note that the explanation of Fig. 16 will mainly focus on the differences from Fig. 11. The processing of steps S1 to S3 is the same as that of Fig. 11.

[0101] In step S3, if the reproducibility of the film thickness during one cycle does not satisfy the desired standard, the process proceeds to step S3-2.

[0102] In step S3-2, the power prediction unit 64 uses the temperature power table and the temperature correction table used in the film formation process to calculate (i) the amount of heater power fluctuation due to a change in the temperature setting value. In addition, the power prediction unit 64 uses the accumulated film thickness power table and the amount of accumulated film thickness fluctuation (15(b)) to calculate (ii) the amount of heater power fluctuation due to a change in accumulated film thickness. The power prediction unit 64 adds (i) and (ii) to the heater power Pw0 of the log of any film formation result (selected by the user) performed in step S2, thereby predicting the heater power of film formation processes other than the selected film formation process (for example, film formation processes of 50 and 100 [nm] when a film formation process with an accumulated film thickness of 0 [nm] is selected).

[0103] In the next step S4, as explained in Fig. 12, the temperature correction information generating unit 62 determines the range of the temperature setting value that can be varied by combining the determined "power fluctuation range" and the "model of the power fluctuation amount for a 1°C change in temperature (temperature power table)". If the predicted heater power value is 100%, the temperature correction information generating unit 62 always varies the temperature correction value of the temperature correction table in the direction that decreases the heater power, and conversely, if the heater power is 0%, the temperature correction information generating unit 62 always varies the temperature correction value of the temperature correction table in the direction that increases the power.

[0104] In this way, the temperature correction information calculation device 4 of this embodiment can correct the temperature correction table with the predicted heater power instead of the heater power for the film formation process selected by the user, thereby improving the accuracy of temperature control during film formation.

[0105] [Effects of the Temperature Correction Information Calculation Device of the Present Embodiment] FIG. 17 is a diagram for explaining the effect achieved by the prediction of the heater power described in this embodiment.

[0106] (1) Operability First, in the comparative technique, the user only needs to select the log of one film forming process in one cycle, and therefore the usability is good. In the present embodiment, the good usability can be maintained.

[0107] (2) Calculation accuracy In the comparative technique, the heater power of one film formation process in one cycle was regarded as the heater power of all film formation processes, which may have reduced calculation accuracy of the temperature correction table. In the present embodiment, the heater power is predicted in all film formation processes in one cycle, which improves the calculation accuracy of the temperature correction table.

[0108] [Major Effects] As described above, the heat treatment system of this embodiment predicts the heater power for each cycle of film formation processing, and therefore can correct the temperature correction table when the heater power is saturated so as not to be saturated. Therefore, the semiconductor manufacturing apparatus 2 can form a film while controlling the temperature during film formation, making it easier to obtain a target film thickness, etc.

[0109] 〔others〕 In this embodiment, the temperature correction information calculation device 4 shown in FIG. 1 performs model learning and generates the temperature correction table, but the semiconductor manufacturing equipment 2 may have the function of the temperature correction information calculation device 4.

[0110] Furthermore, the temperature correction information calculation device 4 may be a server connected to a network. The semiconductor manufacturing apparatus 2 can communicate with the temperature correction information calculation device 4 to obtain the temperature correction table. The temperature correction information calculation device 4 may be present on-premise or in the cloud.

[0111] 1 is one example, and there are various system configurations depending on the application and purpose. The division of the devices such as the host computer 3, the semiconductor manufacturing device 2, the measuring device 60, and the temperature correction information calculation device 4 in FIG. 1 is one example.

[0112] For example, the heat treatment system 1 can have various configurations, such as a configuration in which at least two of the host computer 3, the semiconductor manufacturing equipment 2, the measurement equipment 60, and the temperature correction information calculation device 4 are integrated, or a configuration in which they are further divided. For example, a temperature correction information calculation device 4 may be provided for each semiconductor manufacturing equipment 2.

[0113] The semiconductor manufacturing apparatus 2 disclosed in this specification is not limited to a batch processing apparatus, but can also be applied to either a single-wafer apparatus that processes substrates one by one, or a semi-batch apparatus.

[0114] The substrate processing performed by the semiconductor manufacturing apparatus disclosed in this specification may be applied not only to film formation processing, but also to an oxidation apparatus that performs an oxidation process to oxidize the surface region of a semiconductor wafer, a diffusion apparatus that diffuses (dopes) impurities into the surface region of a semiconductor wafer, an annealing apparatus, an etching apparatus, and the like.

[0115] The semiconductor manufacturing apparatus 2 disclosed in this specification may be an apparatus that processes a substrate using plasma. [Explanation of symbols]

[0116] 1. Heat Treatment System 2. Semiconductor manufacturing equipment 4 Temperature correction information calculation device 61 Acquisition Department 62 Temperature correction information generation section 63 Model Learning Department 64 Power Prediction Section

Claims

1. A temperature correction information calculation device for a semiconductor manufacturing device that performs a film formation process on a processing object by controlling a temperature using a heater so as to approach a set temperature corrected according to an accumulated film thickness accumulated on an inner wall of the semiconductor manufacturing device, a storage unit that stores a temperature correction value for correcting the set temperature; an acquisition unit that acquires a first heater power applied to the heater, the first heater power being included in log information generated by execution of the film formation process; a power prediction unit that predicts a second heater power by adding a fluctuation amount of the heater power due to a change in the set temperature to the first heater power; a temperature correction information generating unit that corrects the temperature correction value based on the second heater power predicted by the power predicting unit, the power prediction unit calculates a variation in heater power due to a change in the accumulated film thickness using a model in which a variation in temperature and a variation in film thickness are associated with each other, and a cumulative film thickness power table in which a variation in accumulated film thickness and a variation in heater power are associated with each other; a fluctuation amount of the heater power due to a change in the cumulative film thickness is further added to the first heater power to predict the second heater power; Temperature correction information calculation device.

2. 2. The temperature correction information calculation device according to claim 1, wherein the power prediction unit calculates a fluctuation amount of the heater power due to a change in the set temperature by using the temperature correction value corresponding to a cumulative film thickness used in the film formation process and a temperature-power table in which a fluctuation amount of the temperature and a fluctuation amount of the heater power are corresponding to each other.

3. The reaction tube of the semiconductor manufacturing equipment is divided into a plurality of zones, a temperature correction table having the temperature correction value for each of the zones, the temperature power table having a heater power fluctuation amount for each of the zones in one column and a heater power fluctuation amount for each of the zones in one row; 3. The temperature correction information calculation device according to claim 2, wherein the power prediction unit multiplies the temperature correction value corresponding to a zone by a fluctuation amount of the heater power in one column corresponding to the zone, and adds the multiplied values ​​in the row direction of the temperature power table to calculate, for each zone, a fluctuation amount of the heater power due to a change in the set temperature.

4. The reaction tube of the semiconductor manufacturing equipment is divided into a plurality of zones, the model has a variation in film thickness for each zone, the cumulative film thickness power table has a variation in heater power for each zone in correspondence with the cumulative film thickness, 2. The temperature correction information calculation device according to claim 1, wherein the power prediction unit calculates the amount of heater power fluctuation due to a change in the cumulative film thickness by multiplying the amount of film thickness fluctuation corresponding to a zone by the amount of heater power fluctuation corresponding to the zone.

5. 5. The temperature correction information calculation device according to claim 1, wherein the power prediction unit predicts the second heater power for each zone and each accumulated film thickness.

6. A semiconductor manufacturing device comprising the temperature correction information calculation device according to any one of claims 1 to 5.

7. 1. A method for calculating temperature correction information for a semiconductor manufacturing apparatus that performs a film formation process on a processing object by controlling a temperature using a heater so as to approach a set temperature corrected according to an accumulated film thickness accumulated on an inner wall of the semiconductor manufacturing apparatus, comprising: acquiring a first heater power applied to the heater, the first heater power being included in log information generated by execution of the film forming process; predicting a second heater power by adding a fluctuation amount of the heater power due to a change in the set temperature to the first heater power; calculating a heater power fluctuation amount due to a change in the accumulated film thickness using a model in which the temperature fluctuation amount and the film thickness fluctuation amount are associated with each other and a cumulative film thickness power table in which the accumulated film thickness fluctuation amount and the heater power fluctuation amount are associated with each other; a step of predicting the second heater power by adding a fluctuation amount of the heater power due to a change in the cumulative film thickness to the first heater power; correcting a temperature correction value stored in a memory unit by the predicted second heater power; The temperature correction information calculation method includes the steps of:

8. A temperature correction information calculation device for a semiconductor manufacturing device that uses a heater to control the temperature so as to approach a set temperature corrected according to a cumulative film thickness accumulated on an inner wall of the semiconductor manufacturing device and performs a film formation process on a processing object, an acquisition unit that acquires a first heater power applied to the heater, the first heater power being included in log information generated by execution of the film formation process; a power prediction unit that predicts a second heater power by adding a fluctuation amount of the heater power due to a change in the set temperature to the first heater power; a temperature correction information generating unit that corrects a temperature correction value stored in a storage unit based on the second heater power predicted by the power predicting unit; the power prediction unit calculates a variation in heater power due to a change in the accumulated film thickness using a model in which a variation in temperature and a variation in film thickness are associated with each other, and a cumulative film thickness power table in which a variation in accumulated film thickness and a variation in heater power are associated with each other; a program for predicting the second heater power by further adding a fluctuation amount of the heater power due to a change in accumulated film thickness to the first heater power;

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