Method for calculating output power limit and semiconductor process equipment

Abstract

The application provides an output power limit value calculation method and a semiconductor process equipment, which are applied to a heating disc, the heating disc comprising a first heating element and a temperature sensor, the temperature sensor being used for detecting the temperature of the first heating element, the method comprising: obtaining historical operation data of the first heating element; wherein the historical operation data comprises historical output power and a temperature value detected by the temperature sensor; determining a heat consumption power required when the first heating element is heated based on the output power and the heating speed of the first heating element in the historical operation data, taking the heat consumption power as a power lower limit value of the first heating element in the heating stage; and calculating a heat supply power of the first heating element at a preset heating speed based on the heat consumption power, taking the heat supply power as a power upper limit value of the first heating element in the heating stage. The application can avoid large fluctuations in the temperature of the first heating element, and improves the stability of temperature control.

Description

Technical Field

[0001] This invention relates to the field of heating equipment technology, and in particular to a method for calculating output power limits and semiconductor process equipment. Background Technology

[0002] In semiconductor processes, the heating system of some semiconductor process equipment (such as the heating plate of silicon wafers) usually includes two sets of heating elements that have a significant impact on each other. One heating element is equipped with a temperature control point (i.e., a temperature sensor), while the other heating element is not equipped with a temperature control point. The heating element with a temperature control point usually performs closed-loop control of the heating power based on the actual detected temperature, while the heating element without a temperature control point performs open-loop control of the heating power.

[0003] For heating elements with temperature control points, the relevant output power control technology typically employs control algorithms such as Proportional-Integral-Derivative (PID) control. The temperature collected from the temperature control point is input into the temperature controller loop, and the load is controlled based on the controller's output value. Simultaneously, the heating rate is set, and the output power of the heating element is limited. Limiting the heater's output power is generally suitable for heating equipment with significant temperature lag, usually caused by a large distance between the temperature control point and the heating element, or a low heat transfer coefficient in the heating equipment itself. A slow temperature response from the temperature sensor makes it difficult to control the heat output of the heating element. For example, if the temperature sensor detects that the current temperature is below the set value, the heating element continues to output power, but the temperature does not rise. If the output power is increased further, and the temperature reaches the set value, the accumulated heat from the heating element causes the temperature to rise again. If the temperature exceeds the set value, the output power of the heating element will decrease rapidly. However, because the temperature decrease is slow, the output power continues to decrease during this period, and this cycle repeats, controlling the heating element's output power. The larger the fluctuation range of the heating element's output power, the more likely it is to cause a larger temperature fluctuation range. However, the relevant output power control technology does not set a reasonable output power range. The calculated output power is often much greater than the actual heat consumption required, resulting in large temperature fluctuations of the heating element and low temperature control stability. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide an output power limit calculation method and semiconductor process equipment that can meet the heating power requirements of the first heating element, while limiting the fluctuation range of the output power of the first heating element, so that the heating capacity is relatively stably converted into the heating rate, avoiding large fluctuations in the temperature of the first heating element, and improving the stability of temperature control.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of the present invention are as follows:

[0006] In a first aspect, embodiments of the present invention provide an output power limit calculation method applied to a heating plate of a semiconductor process equipment. The heating plate includes a first heating element and a temperature sensor. The temperature sensor is used to detect the temperature of the first heating element. The output power limit calculation method includes: acquiring historical operating data of the first heating element; wherein the historical operating data includes historical output power and temperature value detected by the temperature sensor; determining the heat consumption power required for the first heating element to heat up based on the output power and heating rate of the first heating element in the historical operating data, and using the heat consumption power as the lower limit of the power of the first heating element in the heating stage; calculating the heating power of the first heating element at a preset heating rate based on the heat consumption power, and using the heating power as the upper limit of the power of the first heating element in the heating stage.

[0007] Furthermore, this embodiment of the invention provides a first possible implementation of the first aspect, wherein determining the heat consumption power required for the first heating element to heat up based on the output power and heating rate of the first heating element in the historical operating data includes: obtaining operating data for a preset duration from the historical operating data, denoted as target operating data; wherein the historical operating data also includes a curve showing the temperature change of the first heating element over time, and the temperature of the first heating element fluctuates multiple times within the preset duration; calculating the average output power of the first heating element within the preset duration based on each output power of the first heating element in the target operating data, and obtaining a set value for the heating rate of the first heating element within the preset duration; obtaining operating data for a preset number of heating segments from the target operating data, and calculating the average output power and average heating rate of each heating segment based on the operating data of each heating segment; wherein the heating segment is the temperature rise phase detected by the temperature sensor; and determining the heat consumption power required for the first heating element to heat up based on the average output power of the first heating element within the preset duration, the set value for the heating rate, and the average output power and average heating rate of the heating segment.

[0008] Furthermore, this embodiment of the invention provides a second possible implementation of the first aspect, wherein the formula for calculating the heat consumption power is:

[0009] in, The heat dissipation power, The average output power of the first heating element during the preset time period. The set value is the heating rate of the first heating element within the preset time period. The average output power of the heating section, The average heating rate of the heating section.

[0010] Furthermore, this embodiment of the invention provides a third possible implementation of the first aspect, wherein the formula for calculating the heating power is: ;

[0011] in, The heating power is... The preset heating rate, It is the ratio coefficient between the power of the first heating element and the heating rate.

[0012] Furthermore, this embodiment of the invention provides a fourth possible implementation of the first aspect, wherein the formula for calculating the proportionality coefficient is: ) / ,or, .

[0013] Furthermore, this embodiment of the invention provides a fifth possible implementation of the first aspect, wherein the operating data of the heating segment includes temperature data and output power data, and the calculation of the average output power and average heating rate of the heating segment based on the operating data of each heating segment includes: calculating the average output power and average heating rate of each heating segment based on the operating data of the heating segment; and calculating the average output power of the heating segment based on the average output power of each heating segment; wherein the formula for calculating the average output power is: , This represents the average output power of the m-th heating stage. The average output power, The preset quantity is used; the average heating rate of the heating segment is calculated based on the average heating rate of each heating segment; wherein, the formula for calculating the average heating rate is: , The average heating rate, This represents the average heating rate of the m-th heating segment.

[0014] Secondly, embodiments of the present invention also provide a semiconductor process apparatus, including: a heating plate for heating a wafer to be processed; the heating plate includes: a first heating element, a temperature sensor, and a temperature controller; the temperature sensor is used to detect the temperature of the first heating element; the temperature controller is used to calculate a lower power limit and an upper power limit of the first heating element based on the output power limit calculation method of any one of the first aspects, so as to limit the output power range of the first heating element.

[0015] Furthermore, this embodiment of the invention provides a first possible implementation of the second aspect, wherein the heating plate further includes a second heating element, the distance between the temperature sensor and the first heating element is less than the distance between the temperature sensor and the second heating element; the temperature control method of the first heating element is closed-loop control, and the temperature controller is used to determine the target output power of the first heating element based on the current temperature detected by the temperature sensor; the temperature control method of the second heating element is open-loop follower control, and the temperature controller is also used to control the output power of the second heating element based on the target output power, wherein the output power of the second heating element is positively correlated with the target output power.

[0016] Furthermore, this embodiment of the invention provides a second possible implementation of the second aspect, wherein the temperature controller is configured to control the output power of the first heating element to be the upper power value when the target output power is greater than the upper power value; the temperature controller is also configured to control the output power of the first heating element to be the lower power value when the target output power is less than the lower power value.

[0017] Furthermore, the present invention provides a third possible implementation of the second aspect, wherein the first heating element and the second heating element are both annular heating tubes, the radius of the first heating element is smaller than the radius of the second heating element, and the second heating element is sleeved outside the first heating element, and the temperature sensor of the first heating element is located in the central region of the annular heating tube.

[0018] This invention provides a method for calculating output power limits and a semiconductor process equipment. By estimating the heat consumption power required for the first heating element in the heating plate of the semiconductor process equipment to heat up and the heat supply power of the first heating element at a preset heating rate, and using the heat consumption power as the lower limit of the power of the first heating element during the heating stage and the heat supply power as the upper limit of the power of the first heating element during the heating stage, the heating power requirements of the first heating element can be met, while limiting the fluctuation range of the output power of the first heating element. This makes the heating capacity relatively stable in conversion into the heating rate, avoids large temperature fluctuations of the first heating element, and improves the stability of temperature control.

[0019] Other features and advantages of the embodiments of the present invention will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above in the embodiments of the present invention.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1a A schematic diagram of a heating system with a single temperature measuring point is shown.

[0023] Figure 1b A schematic diagram of a heating system with multiple temperature measuring points is shown.

[0024] Figure 1c A schematic diagram of the relevant temperature control principle is shown;

[0025] Figure 2 A flowchart of an output power limit calculation method provided by an embodiment of the present invention is shown;

[0026] Figure 3 An example temperature rise curve provided by an embodiment of the present invention is shown;

[0027] Figure 4 This diagram illustrates a heating section selection method provided by an embodiment of the present invention.

[0028] Figure 5a The graph shows temperature measurement values ​​for the relevant temperature control technologies.

[0029] Figure 5b The figure shows a temperature measurement curve after setting the upper and lower power limits of the first heating element, as provided in an embodiment of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be described below in conjunction with the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0031] Currently, in semiconductor manufacturing processes, some products sometimes have heating systems consisting of two heating elements that significantly influence each other. Depending on the number of temperature control points, there are two scenarios for such heating systems. The first scenario is that only one temperature control point can be installed in one of the heating elements, while the other heating element has no temperature control point and can only be controlled in an open-loop manner. The second scenario is that each of the two heating elements in the heating system can have its own temperature control point installed, and both are controlled in a closed-loop manner.

[0032] The first scenario involves installing a temperature control point (i.e., a temperature sensor) on one of the heating elements in the heating system, such as a circular heating plate (Heater) used in the semiconductor field to heat silicon wafers, see example... Figure 1a The diagram shows a heating system with a single temperature measuring point. The outer gray coil is the outer heating element, and the inner gray coil is the inner heating element. The two quadrilaterals are two temperature measuring points, one of which serves as a temperature control point. Due to the structure of the heating system, a temperature measuring point cannot be installed in the outer zone. The temperature control point is relatively close to the inner heating element, allowing for the detection of the temperature of the inner heating element.

[0033] The second scenario involves installing temperature control points within the heating elements of the heating system, such as in the heating systems for chamber walls in the semiconductor field, see example... Figure 1b The diagram shown illustrates a heating system with multiple temperature measurement points. Figure 1b The quadrilateral in the design is a metal wall. The four large circles at the four corners of the quadrilateral are heating elements, and the four small circles are temperature measuring points. That is, each heating element is equipped with a corresponding temperature measuring point.

[0034] In both of the above situations, when controlling the temperature, the temperature measurement point is affected by the two heating systems, and the temperature fluctuation during the heating process and after reaching the set value is sometimes unsatisfactory, which can lead to poor process results.

[0035] The first scenario currently employs a follower control method, also known as an open-loop control heating system. Because one of the heating elements lacks a temperature sensor, its output power is calculated based on the closed-loop system's output power. Since a temperature sensor cannot be installed, during initial heating testing, measurements can only be taken using specialized instruments under specific conditions and methods. After normal operation, the true temperature cannot be determined. Some heating systems, such as Heater, have very high requirements for the temperature difference between the two heating elements; if the temperature difference exceeds a certain value, the heating element will be damaged.

[0036] For heating systems with temperature measurement points, most temperature control technologies still use the traditional PID (Proportional Integral Derivative) control algorithm, see, for example... Figure 1c The schematic diagram of the relevant temperature control principle shows that the actual temperature value and the temperature set value collected by the temperature measuring point are input into the input circuit of the temperature controller. The temperature controller calculates the power percentage and controls the load through the power regulator or solid-state relay. In addition, it also has functions such as setting the temperature rise rate and limiting the power output to ensure that the temperature rise rate is moderate. However, the power limit is usually estimated by experience or test data and lacks verification and optimization. The following calculations of output power are all power percentage calculations, referred to as power calculations.

[0037] Limiting power is suitable for systems with significant temperature lag. In the first scenario, although one heating element has a temperature sensor, there is still a distance between the sensor and the heating element. Factors such as a slightly large distance between the sensor and the heating element, or a low heat transfer coefficient in the first heating element, can lead to temperature control lag and slow temperature response, making it difficult to control the amount of heat generated. For example, if the current temperature is below the set value, the heating element continues to output power, but the temperature does not rise. If the output power is increased further, and the set value is reached, the heating element will continue to rise due to heat accumulation. Because it continues to exceed the set value, the output power will decrease rapidly, but the temperature will drop slowly. This continuous decrease in output power will cause the temperature to deviate significantly from the set value in the next cycle. Therefore, in this heating system, the larger the range of output power fluctuations, the more likely it is to cause a larger range of temperature fluctuations.

[0038] The second scenario involves using two independent control systems, such as separate PID control algorithms. However, due to individual differences and environmental variations between the two heating elements, the following situation may occur after reaching the set temperature: one heating element has stopped heating but its temperature continues to rise, while the other heating element has not yet reached the set temperature, and although the power output is increased, the temperature rise rate is very slow. In this case, the only solution is to limit the power of the heating element with the higher temperature through experimental data. The specific power limit value needs to be repeatedly adjusted and verified. Therefore, in this scenario, the control effect of independently controlling the two heating elements may be lower than that of the first scenario. Related technologies typically use the control method of the first scenario for temperature regulation.

[0039] While temperature control technologies for heating elements employ control algorithms such as PID control, which can sometimes achieve good results, the effectiveness is sometimes less than ideal when controlling the temperature of two significantly interdependent heating elements. The main problem lies in the lack of estimation of the heating element's output power. The output power of the heating element is often much greater than the actual required heat consumption. This is especially true when the heating process is unexpectedly interrupted or disturbed, leading to increased difficulty in temperature control and greater temperature fluctuations during restart.

[0040] To address the aforementioned issues, this invention provides a method for calculating output power limits and a semiconductor process apparatus. The following provides a detailed description of this invention.

[0041] This embodiment provides a method for calculating output power limits. This method can be applied to a heating plate in semiconductor process equipment. The heating plate includes a first heating element and a temperature sensor. The temperature sensor is used to detect the temperature of the first heating element. See [link to documentation]. Figure 2 The flowchart shown illustrates the method for calculating the output power limit. This method mainly includes the following steps:

[0042] Step S202: Obtain historical operating data of the first heating element.

[0043] The aforementioned historical operating data includes historical output power and temperature values ​​detected by the temperature sensor; during the operation of the first heating element, the temperature value of the first heating element is detected in real time or periodically by the temperature sensor, and data on the changes in temperature and output power over time are recorded.

[0044] In one specific embodiment, the heating plate further includes a second heating element. The distance between the temperature sensor and the first heating element is smaller than the distance between the temperature sensor and the second heating element. Since the temperature sensor is closer to the first heating element, the temperature sensor is used to detect the current temperature of the first heating element.

[0045] Step S204: Based on the output power and heating rate of the first heating element in the historical operating data, determine the heat consumption power required for the first heating element to heat up, and use the heat consumption power as the lower limit value of the power of the first heating element in the heating stage.

[0046] Since there is currently no formula to calculate the relationship between heat dissipation and heat consumption power on temperature, historical operating data of the first heating element can be obtained to determine its temperature rise curve and historical output power curve. Based on this historical operating data, the relationship between the output power and the temperature rise rate of the first heating element can be determined. Considering factors such as heat dissipation during the use of the first heating element, in order for the first heating element to heat up (i.e., the temperature detected by the temperature sensor gradually increases), the output power of the first heating element must reach a certain level before the temperature begins to rise. Based on the relationship between the temperature rise rate and the output power of the first heating element during the heating process, the required output power for the first heating element to heat up can be determined, denoted as heat consumption power. This heat consumption power is used as the lower limit value of the power of the first heating element during the heating stage. That is, when the output power of the first heating element is greater than this lower limit value, the first heating element begins to heat up; when the output power of the first heating element is less than or equal to this lower limit value, the first heating element maintains its current temperature or cools down.

[0047] To determine the relationship between output power and heating rate, the thermodynamic formula is used. , For heat, For specific heat, For quality, This refers to the temperature difference.

[0048] The inventors discovered that by dividing both sides of the thermodynamic formula by time, and taking specific heat and mass as constants, thermal power can be obtained. With the rate of temperature rise The output power and the heating rate are directly proportional. Based on the historical operating data of the first heating element, the functional relationship between the output power and the heating rate can be determined.

[0049] Step S206: Calculate the heating power of the first heating element at the preset heating rate based on the heat consumption power, and use the heating power as the upper limit of the power of the first heating element during the heating stage.

[0050] Based on the relationship between the output power of the first heating element and the heating rate, the output power required by the first heating element to meet the preset heating rate can be calculated and denoted as the heating power. When the output power of the first heating element exceeds the heating power, the heating rate will be too large, exceeding the required heating rate, which will easily cause temperature fluctuations. Therefore, the heating power is taken as the upper limit of the power of the first heating element in the heating stage.

[0051] In actual heating, the temperature rise curve detected by the temperature sensor is the most important monitoring data. Although the distance between the temperature sensor and the first heating element is smaller than the distance between the temperature sensor and the second heating element, and the temperature sensor is used to detect the temperature of the first heating element, there is still a certain distance between the temperature sensor and the first heating element. This causes the temperature feedback of the first heating element to be lagging. Sometimes, even using PID control for power output control cannot solve the problem of large temperature fluctuations and overshooting. The main reason is that the heating power (i.e., the actual output power) of the first heating element is too large, and a lot of heat is accumulated on the first heating element. As time is released, although the power is reduced, the temperature rebounds.

[0052] The output power of the first heating element does not change synchronously with the temperature. This lag is related to the heat transfer coefficient of the material of the first heating element. For example, aluminum has a much better heat transfer coefficient than stainless steel and ceramic, resulting in less lag and relatively easier temperature control. However, for heating systems with a single temperature control point and two heating elements, especially when the distance between the control point and the two heating elements varies, temperature control is more difficult. Since temperature fluctuations are mainly due to the deviation of the supplied heat from the actual required heat consumption, to reduce temperature fluctuations, it is necessary to estimate the heat consumption power of the first heating element and calculate the supplied heat power based on the heat consumption power of the first heating element. This gives the output power of the first heating element a smaller limiting range, thus reducing temperature fluctuations.

[0053] The output power limit calculation method provided in this embodiment estimates the heat consumption power required for the first heating element to heat up and the heating power of the first heating element at a preset heating rate. The heat consumption power is used as the lower limit of the power of the first heating element during the heating stage, and the heating power is used as the upper limit of the power of the first heating element during the heating stage. This method can meet the heating power requirements of the first heating element, while limiting the fluctuation range of the output power of the first heating element. It makes the heating capacity relatively stable in the form of heating rate, avoids large fluctuations in the temperature of the first heating element, and improves the stability of temperature control.

[0054] In one embodiment, to improve the accuracy of heat consumption power calculation, this embodiment provides an implementation method for determining the heat consumption power required for the first heating element to heat up based on the output power and heating rate of the first heating element in historical operating data. The specific steps are as follows:

[0055] Step (1): Obtain the running data for a preset duration from the historical running data, and record it as the target running data.

[0056] The aforementioned historical operating data also includes the curve of the temperature change of the first heating element over time, with the temperature of the first heating element fluctuating multiple cycles within a preset time period.

[0057] Since there is no readily available heat transfer formula in physics to calculate the relationship between heat dissipation and heating power of a device and its temperature, it is necessary to use experimental methods to collect the temperature rise curve and output power data of the first heating element. Based on the temperature rise and fall pattern, a time period of operating data is selected from the historical operating data of the first heating element for calculation, thereby estimating the heating power and heat consumption of the first heating element.

[0058] The aforementioned historical operating data also includes the temperature setpoint. Based on the characteristics of the temperature rise curve, the actual temperature detected by the temperature sensor will fluctuate around the temperature setpoint. Considering that the local temperature range may have special characteristics, a longer time period should be selected as much as possible. However, a longer time period results in greater temperature changes, which in turn leads to greater changes in the heat consumption power of the first heating element. Therefore, a compromise can be made. Based on the temperature fluctuation pattern, 6-7 fluctuation cycles are selected as a calculation time period. The duration required for these 6-7 fluctuation cycles is the preset duration.

[0059] Step (2): Based on the output power of each of the first heating elements in the target operating data, calculate the average output power of the first heating element within a preset time period, and obtain the heating rate setting value of the first heating element within the preset time period.

[0060] The aforementioned historical operating data also includes the set value of the heating rate of the first heating element, obtaining the output power points of the first heating element recorded in the historical operating data within a preset time period, calculating the average output power of the first heating element within the preset time period, and obtaining the set value of the heating rate of the first heating element within the preset time period. .

[0061] Average output power of the first heating element within a preset time period , The average output power of the heater over a preset time period. The number of output power records within a preset time period. This represents the i-th output power value within a preset time period.

[0062] For example, see such as Figure 3 The example temperature rise curve shown is as follows. Figure 3 The document provides an example of the temperature rise curve and corresponding power output curve of the first heating element within a preset time period. During this period, the output power of the first heating element changes repeatedly, and the actual temperature value (i.e., the temperature detected by the temperature sensor) fluctuates around the set temperature value. It can be approximately assumed that the heat supply and heat consumption of the first heating element are basically balanced during this period, and the heat difference between the two achieves the temperature rise of the first heating element. The average output power of the first heating element during this period is calculated. In this embodiment, the power is calculated as a percentage of the total power.

[0063] Step (3): Obtain the operating data of a preset number of heating sections from the target operating data, and calculate the average output power and average heating rate of each heating section based on the operating data of each heating section.

[0064] The heating segment is the stage where the temperature rises as detected by the temperature sensor, that is, the line segment where the temperature rises from a trough to a peak.

[0065] The inventors discovered that the actual temperature value detected within a certain period sometimes deviates positively from the set temperature value, and sometimes negatively. This deviation generally follows the same trend as the power output fluctuation in the previous period. In other words, if the temperature deviates positively in a given period, the power output in the previous period is generally also positively deviating, and vice versa. Therefore, essentially, fluctuations in output power, after a period, are reflected in the temperature using the same curve. The heat consumption power is assumed to be approximately constant over a period of time, and the temperature value at each point is generated from the accumulation of previous heat supply power. Based on this principle, see [reference needed]. Figure 4The diagram showing the selection of heating segments illustrates that the temperature segment circled in the first circle is primarily influenced by the power segment enclosed in the first rectangle, and the temperature segment circled in the second circle is primarily influenced by the power segment enclosed in the second rectangle. A preset number of heating segments can be selected from the preset duration of operating data. This preset number can range from 2 to 5, with a preferred value of 3. Figure 4 As shown, three temperature rise segments can be selected, and the average output power and average heating rate of the three temperature rise segments can be calculated.

[0066] In one specific implementation, the average output power and average heating rate of each heating segment are calculated based on the operating data of the heating segment.

[0067] The average output power of each heating stage is calculated based on the average output power of each heating stage; the formula for calculating the average output power is as follows:

[0068] ,

[0069] This represents the average output power of the first heating stage. This represents the average output power of the second heating stage, and so on. It is the average output power of the m-th heating segment (i.e., the average of the maximum and minimum output power of the heating segment, or the average of all output powers). Average output power, This is the preset quantity, i.e., the number of heating sections.

[0070] Since the actual output power of the first heating element changes according to the PID control algorithm, it is not linear. The greater the deviation from the temperature setpoint, the faster the output power changes and the faster it will reach the peak. The temperature change is also not linear because it is also affected by the current real-time heating power. Even during the process of output power decrease, as long as the output power is greater than the heat consumption power of the equipment, it will still have an effect on raising the temperature. To simplify the calculation, the average output power of each heating stage can be calculated according to the average of the peak and trough in the figure.

[0071] The average heating rate of each heating segment is calculated based on the average heating rate of each heating segment; the formula for calculating the average heating rate is as follows:

[0072] ,

[0073] The average heating rate, This represents the average heating rate of the first heating stage. This represents the average heating rate of the second heating stage. It is the average heating rate of the m-th heating segment (the difference between the maximum and minimum temperatures in this heating segment divided by the time difference).

[0074] Step (4): Determine the heat consumption power required for the first heating element to heat up based on the average output power of the first heating element within a preset time, the set value of the heating rate, and the average output power and average heating rate of the heating segment.

[0075] The above thermodynamic formulas Dividing both sides of the formula by time yields the power. With heating rate Proportional, we can obtain:

[0076] ) /

[0077] The average output power of the first heating element within a preset time period Heating rate setting value and the average output power of the heating section and average heating rate By inputting the above formula, the heat consumption power can be calculated. and the ratio of the power of the first heating element to the heating rate .

[0078] In one specific implementation, the formula for calculating heat consumption power is:

[0079] in, For heat dissipation power, The average output power of the first heating element within a preset time period. This is a set value for the heating rate of the first heating element within a preset time period. This represents the average output power during the heating phase. This represents the average heating rate during the heating phase.

[0080] For example, refer to the operating data table of the first heating element shown in Table 1 below, and calculate the heat consumption power of the first heating element based on the data in Table 1:

[0081] Table 1. Operating Data of the First Heating Element

[0082]

[0083] but = (28% + 65% + 5% + 83% + 78% + 5% + 23% + 42% + 32%) / 11 = 32.8%

[0084]

[0085] Heating power can also be calculated based on the ratio of power to heating rate.

[0086] ) /

[0087] In one implementation, the formula for calculating heating power is:

[0088] in, Heating power (%) The preset heating rate (°C / min) is used. When the first heating element needs to meet a certain temperature rise rate, the required preset heating rate can be input into the above-mentioned heating power calculation formula to calculate the heating power. The output power of the first heating element is controlled to be the heating power, and the heating rate of the first heating element is the preset heating rate.

[0089] In one embodiment, the formula for calculating the proportionality coefficient is: ) / ,or, , This is the ratio of the power of the first heating element to the heating rate.

[0090] For example, based on the operating data of the first heating element provided in Table 1 above, when the required heating rate of the first heating element is... At 5℃ / min,

[0091] Heating power .

[0092] Please refer to Table 2 below for the heat consumption power of the first heating element and the heating power data when the preset heating rate is 5℃ / min:

[0093] Table 2. Heat consumption power of the first heating element and heat supply power data when the preset heating rate is 5℃ / min.

[0094]

[0095] As shown in Table 2 above, when the temperature range of the first heating element is 200-300℃, if the first heating element needs to be heated at a heating rate of 5℃ / min, limiting the power of the first heating element to between 30.5% and 34.4% can reduce temperature fluctuations.

[0096] See also Figure 5a The temperature measurement curves of the relevant temperature control technologies shown are as follows: Figure 5b The graph shown depicts temperature measurements after setting the upper and lower power limits for the first heating element. Figure 5aThe temperature curves detected after controlling the power of the first heating element using existing temperature control technology are shown. Figure 5b The temperature curves detected after limiting the upper and lower power limits of the first heating element using the method provided in this embodiment are shown. Figure 5a and Figure 5b It can be seen that after setting the upper and lower limits of the power of the first heating element, the fluctuation of the temperature measurement value is significantly reduced, and the temperature stability is improved.

[0097] The output power limit calculation method of the first heating element provided in this embodiment calculates the heat consumption power and heat supply power of the first heating element in a heating system with a single temperature measuring point and two first heating elements, and then estimates the range of the heat supply power of the first heating element, so that the heat supply can be converted into a relatively stable temperature rise rate, achieving a good temperature tracking effect and improving the stability of temperature control.

[0098] Corresponding to the output power limit calculation method provided in the above embodiments, this embodiment of the invention provides a semiconductor process equipment, including: a heating plate, which is used to heat the wafer to be processed;

[0099] The heating plate includes: a first heating element, a temperature sensor, and a temperature controller; the temperature sensor is used to detect the temperature of the first heating element.

[0100] The temperature controller is used to calculate the lower power limit and upper power limit of the first heating element based on the output power limit calculation method provided in the above embodiment, so as to limit the output power range of the first heating element, that is, to limit the output power of the first heating element to the range of the lower power limit to the upper power limit, so as to reduce the temperature fluctuation range of the first heating element and improve the stability of the temperature control of the first heating element.

[0101] In one embodiment, the heating plate provided in this embodiment further includes a second heating element, and the distance between the temperature sensor and the first heating element is less than the distance between the temperature sensor and the second heating element; the temperature control method of the first heating element provided in this embodiment is closed-loop PID control, and the temperature controller is used to determine the target output power of the first heating element based on the current temperature detected by the temperature sensor; the current temperature and target temperature of the first heating element detected by the temperature sensor are input into the PID controller to obtain the target output power of the first heating element, thereby realizing closed-loop PID control of the temperature of the first heating element.

[0102] The temperature control method of the second heating element is open-loop follower control. The temperature controller is also used to control the output power of the second heating element based on the target output power. The output power of the second heating element is positively correlated with the target output power, that is, the output power of the second heating element = target output power * preset proportional coefficient. This proportional coefficient is related to the type of process to be performed on the wafer to be processed. For example, when the temperature requirement of the wafer position corresponding to the second heating element is higher during the process, the value of this proportional coefficient is larger. The output power of the second heating element changes with the target output power of the first heating element, thus realizing open-loop follower control of the second heating element.

[0103] In one embodiment, the temperature controller provided in this embodiment is used to control the output power of the first heating element to the upper limit value when the target output power is greater than the upper limit value;

[0104] The temperature controller is also used to control the output power of the first heating element to the lower power limit when the target output power is less than the lower power limit.

[0105] In one embodiment, the first heating element and the second heating element provided in this embodiment are both annular heating tubes. The radius of the first heating element is smaller than the radius of the second heating element, and the second heating element is sleeved outside the first heating element. The temperature sensor of the first heating element is located in the central area of ​​the annular heating tube, that is, near the center point.

[0106] For example, such as Figure 1a As shown, the second heating element can be the outermost gray annular heating tube, and the first heating element includes two adjacent gray annular heating tubes in the inner ring; the temperature sensor is one of the rhombuses at the center of the circle, and the temperature sensor is close to the first heating element, so it can be used to detect the current temperature of the first heating element.

[0107] The device provided in this embodiment has the same implementation principle and technical effects as the aforementioned embodiments. For the sake of brevity, any parts not mentioned in the device embodiment can be referred to the corresponding content in the aforementioned method embodiment.

[0108] This invention provides a computer-readable medium storing computer-executable instructions. When these computer-executable instructions are invoked and executed by a processor, they cause the processor to implement the methods described in the above embodiments.

[0109] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the system described above can be referred to the corresponding process in the foregoing embodiments, and will not be repeated here.

[0110] The computer program product of the output power limit calculation method provided in the embodiments of the present invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the preceding method embodiments. For specific implementation, please refer to the method embodiments, which will not be repeated here.

[0111] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0112] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0113] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0114] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for calculating output power limits, characterized in that, A heating plate used in semiconductor process equipment, the heating plate including a first heating element and a temperature sensor, the temperature sensor being used to detect the temperature of the first heating element, and the method for calculating the output power limit including: Acquire historical operating data of the first heating element; wherein, the historical operating data includes historical output power and temperature values ​​detected by the temperature sensor; Based on the output power and heating rate of the first heating element in the historical operating data, the heat consumption power required for the first heating element to heat up is determined, and the heat consumption power is used as the lower limit value of the power of the first heating element in the heating stage. The heating power of the first heating element at the preset heating rate is calculated based on the heat consumption power, and the heating power is used as the upper limit of the power of the first heating element during the heating stage. The step of determining the heat consumption power required for the first heating element to heat up based on the output power and heating rate of the first heating element in the historical operating data includes: determining the relationship between the heating rate and the output power during the heating process of the first heating element based on the historical operating data; and determining the heat consumption power required for the first heating element to heat up based on the relationship between the heating rate and the output power and the heating rate of the heating segment in the historical operating data; wherein, the heating segment is the stage of temperature rise detected by the temperature sensor.

2. The method for calculating the output power limit according to claim 1, characterized in that, The step of determining the relationship between the heating rate and the output power during the heating process of the first heating element based on the historical operating data, and determining the heat consumption power required for the heating of the first heating element based on the relationship between the heating rate and the output power and the heating rate during the heating segment in the historical operating data, includes: The operation data for a preset duration is obtained from the historical operation data and recorded as the target operation data; wherein, the historical operation data also includes the curve of the temperature change of the first heating element over time, and the temperature of the first heating element generates multiple fluctuation cycles within the preset duration; Based on the output power of the first heating element in the target operating data, calculate the average output power of the first heating element within the preset time period, and obtain the heating rate setting value of the first heating element within the preset time period. Obtain a preset number of heating segment operation data from the target operation data, and calculate the average output power and average heating rate of each heating segment based on the operation data of each heating segment. The heat consumption required for the first heating element to heat up is determined based on the average output power of the first heating element within the preset time period, the set value of the heating rate, and the average output power and average heating rate of the heating segment.

3. The method for calculating the output power limit according to claim 2, characterized in that, The formula for calculating the heat consumption power is: in, The heat dissipation power, The average output power of the first heating element during the preset time period. The set value is the heating rate of the first heating element within the preset time period. The average output power of the heating section, The average heating rate of the heating section.

4. The method for calculating the output power limit according to claim 3, characterized in that, The formula for calculating the heating power is: ; in, The heating power is... The preset heating rate, It is the ratio coefficient between the power of the first heating element and the heating rate.

5. The method for calculating the output power limit according to claim 4, characterized in that, The formula for calculating the proportionality coefficient is: ) / ,or, .

6. The method for calculating the output power limit according to claim 2, characterized in that, The operating data of the heating section includes temperature data and output power data. The calculation of the average output power and average heating rate of each heating section based on its operating data includes: Based on the operating data of the heating section, calculate the average output power and average heating rate of each heating section. The average output power of the heating segment is calculated based on the average output power of each heating segment; wherein, the formula for calculating the average output power is: , This represents the average output power of the m-th heating stage. The average output power, The preset quantity; The average heating rate of the heating segment is calculated based on the average heating rate of each heating segment; wherein, the formula for calculating the average heating rate is: , The average heating rate, This represents the average heating rate of the m-th heating segment.

7. A semiconductor process apparatus, characterized in that, include: A heating plate, used to heat the wafer to be processed; The heating plate includes: a first heating element, a temperature sensor, and a temperature controller; the temperature sensor is used to detect the temperature of the first heating element. The temperature controller is used to calculate the lower power limit and upper power limit of the first heating element based on the output power limit calculation method according to any one of claims 1-6, so as to limit the output power range of the first heating element.

8. The semiconductor process equipment according to claim 7, characterized in that, The heating plate also includes a second heating element, and the distance between the temperature sensor and the first heating element is smaller than the distance between the temperature sensor and the second heating element; The temperature control method of the first heating element is closed-loop PID control, and the temperature controller is used to determine the target output power of the first heating element based on the current temperature detected by the temperature sensor. The temperature control method of the second heating element is open-loop follower control. The temperature controller is also used to control the output power of the second heating element based on the target output power, wherein the output power of the second heating element is positively correlated with the target output power.

9. The semiconductor process equipment according to claim 8, characterized in that, The temperature controller is used to control the output power of the first heating element to the upper power limit when the target output power is greater than the upper power limit; The temperature controller is also used to control the output power of the first heating element to the lower power limit when the target output power is less than the lower power limit.

10. The semiconductor process equipment according to any one of claims 8-9, characterized in that, Both the first heating element and the second heating element are annular heating tubes. The radius of the first heating element is smaller than that of the second heating element, and the second heating element is sleeved outside the first heating element. The temperature sensor of the first heating element is located in the central area of ​​the annular heating tube.

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