Wafer heating control method and device, electronic equipment and storage medium

Abstract

The invention provides a wafer heating control method and device, electronic equipment and a storage medium, and the method comprises the steps: obtaining a first current heating set value and a first current temperature value of a target wafer at an ith heating stage; a first heating control value is obtained based on the first current heating set value and the first current temperature value through a first PID algorithm; determining a second current heating set value based on the first heating control value, the first current heating set value, the first current temperature value and the temperature upper limit value; obtaining a second heating control value by a second PID algorithm based on a second current heating set value and a second current temperature value of the inner ring heating wire; obtaining a third heating control value by a third PID algorithm based on the second current heating set value and a third current temperature value of the outer ring heating wire; and heating control is performed on the inner ring heating wire and the outer ring heating wire based on the second heating control value and the third heating control value. According to the method, the control accuracy of wafer heating can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wafer heating control, and in particular to a wafer heating control method and device, an electronic device, and a storage medium. BACKGROUND

[0002] Atomic Layer Deposition (ALD) equipment is an advanced technical equipment for thin film preparation, which can control the growth of thin films on various material surfaces with atomic level precision. ALD is a thin film growth technology based on surface saturation reaction, which constructs thin films layer by layer through self-limiting chemical reactions on the substrate surface by alternately introducing two different precursor gases. In the atomic layer deposition equipment, wafer temperature is one of the core control parameters in the ALD process, and wafer temperature directly affects the adsorption rate of the precursor, the reaction activity and the desorption efficiency of the by-product. Therefore, how to control the heating of the wafer is a problem that needs to be solved to ensure the stability of the process. SUMMARY

[0003] The present application provides a wafer heating control method and device, an electronic device, and a storage medium. The accuracy of wafer heating control can be improved. The technical solution is as follows: According to one aspect of the present application, a wafer heating control method is provided, the method comprising: In the i-th heating stage, the first current heating set value of the target wafer in the current heating stage and the first current temperature value of the target wafer are obtained, i is a positive integer; The first current heating set value and the first current temperature value are processed by a first PID algorithm to obtain a first heating control value; Based on the first heating control value, the first current heating set value, the first current temperature value and a temperature upper limit value, a second current heating set value of the inner circle heating wire and the outer circle heating wire is determined, and the temperature upper limit value is a heating temperature upper limit value of the inner circle heating wire and the outer circle heating wire; The second current temperature value of the inner circle heating wire and the third current temperature value of the outer circle heating wire are obtained; The second current heating set value and the second current temperature value are processed by a second PID algorithm to obtain a second heating control value; The second current heating set value and the third current temperature value are processed by a third PID algorithm to obtain a third heating control value; The inner ring heating wire and the outer ring heating wire are heated and controlled based on the second heating control value and the third heating control value respectively, and heat generated by the inner ring heating wire and the outer ring heating wire is used to conduct to the target wafer so as to warm up the target wafer.

[0004] According to another aspect of the present application, a wafer heating control device is provided, the device comprising: The first acquisition module is configured to acquire, in the i-th heating stage, a first current heating setting value of a target wafer in the current heating stage and a first current temperature value of the target wafer, i being a positive integer. The first control module is configured to process the first current heating setting value and the first current temperature value by using a first PID algorithm to obtain a first heating control value. The first determination module is configured to determine a second current heating setting value of an inner ring heating wire and an outer ring heating wire based on the first heating control value, the first current heating setting value, the first current temperature value and a temperature upper limit value, the temperature upper limit value being a heating temperature upper limit value of the inner ring heating wire and the outer ring heating wire. The second acquisition module is configured to acquire a second current temperature value of the inner ring heating wire and a third current temperature value of the outer ring heating wire. The second control module is configured to process the second current heating setting value and the second current temperature value by using a second PID algorithm to obtain a second heating control value. The third control module is configured to process the second current heating setting value and the third current temperature value by using a third PID algorithm to obtain a third heating control value. The heating control module is configured to heat and control the inner ring heating wire based on the second heating control value and heat and control the outer ring heating wire based on the third heating control value, and heat generated by the inner ring heating wire and the outer ring heating wire is used to conduct to the target wafer so as to warm up the target wafer.

[0005] According to an aspect of the present application, an electronic device is provided, comprising a processor and a memory storing a program, the program comprising instructions which, when executed by the processor, cause the processor to perform the wafer heating control method as described above.

[0006] According to another aspect of the present application, a non-transitory computer readable storage medium storing computer instructions is provided, the computer instructions being used to cause the computer to perform the wafer heating control method as described above.

[0007] According to another aspect of the present application, a computer program product is provided, which includes computer instructions stored in a computer readable storage medium. A processor of an electronic device reads the computer instructions from the computer readable storage medium, and the processor executes the computer instructions to cause the computer device to perform the wafer heating control method.

[0008] The technical scheme provided by the embodiments of the present application has at least the following beneficial effects: For each heating stage, after the first PID algorithm of the main loop outputs the first heating control value according to the first current heating set value and the first current temperature value, the first heating control value, the temperature upper limit value of the inner ring heating wire and the outer ring heating wire during heating are used to convert the abstract control amount into the actual temperature reference value of the secondary loop; then the difference between the set value (the first current heating set value) and the measured value (the first current temperature value) of the main loop is superimposed to introduce an error compensation term to obtain the second current heating set value of the secondary loop; so as to accurately control the inner ring heating wire and the outer ring heating wire to heat according to the error between the second current heating set value and the current temperature value of the heating wire (the inner and outer ring heating wires); and the introduction of the error compensation term can also form a dynamic feedforward regulation to accelerate the response speed of the secondary loop to the deviation of the main loop. In addition, the main loop focuses on overall temperature trend control (slow large inertia process), and the secondary loop adjusts the heating power based on the set value generated by the output of the main loop (fast small inertia process), forming a time scale separation control architecture. In addition, the addition of the main loop error term (SV1-PV1) can reflect the system disturbance in real time, and the secondary loop can offset the influence of such interference on the main parameter in advance through rapid adjustment, thereby reducing the control pressure of the main loop. Compared with the traditional step set, the response of the system to the disturbance is smoother, and the steady-state recovery time is shortened. BRIEF DESCRIPTION OF DRAWINGS

[0009] In the following description of exemplary embodiments in conjunction with the accompanying drawings, more details, features and advantages of the present application are disclosed, in which: Figure 1 is a structural schematic diagram of a carrier base provided by an exemplary embodiment of the present application; Figure 2 is a heating process schematic diagram of a heating control system in the related art; Figure 3 is an architecture schematic diagram of a wafer (carrier) heating control system provided by an exemplary embodiment of the present application; Figure 4 shows a flowchart of a wafer heating control method according to an exemplary embodiment of the present application; Figure 5 is a flowchart of a wafer heating control algorithm provided by an exemplary embodiment of the present application; Figure 6A flow chart illustrating another wafer heating control method according to an example embodiment of the present application is shown; Figure 7 FIG. 1 is a structural schematic diagram of a wafer heating control device provided by an embodiment of the present application; Figure 8 A computer processing block diagram of an example electronic device that can be used to implement an embodiment of the present application is shown. DETAILED DESCRIPTION

[0010] Embodiments of the present application will be described in more detail by referring to the drawings. Although certain embodiments of the present application are shown in the drawings, it is understood that the present application can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein, but rather these embodiments are provided so as to more thoroughly and completely understand the present application. It is understood that the drawings and embodiments of the present application are for exemplary purposes only and are not intended to limit the scope of protection of the present application.

[0011] It should be understood that each of the steps recited in the method embodiments of the present application can be executed in different orders and / or in parallel. In addition, the method embodiments can include additional steps and / or omit the execution of the steps shown. The scope of the present application is not limited in this respect.

[0012] The term "comprising" and variations thereof as used in the present application are open-ended, that is, "including but not limited to". The term "based on" is "based, at least in part, on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Related definitions are given throughout the description. It should be noted that the concepts mentioned in the present application are merely used to distinguish different devices, modules or units, and are not intended to limit the functions performed by these devices, modules or units. It should be noted that the terms "one", "multiple", "some" mentioned in the present application are illustrative and not limiting, and those skilled in the art should understand that "one" or "multiple" should be understood as "one or more" unless the context clearly indicates otherwise. The names of the messages or information exchanged between the devices in the embodiments of the present application are merely used for illustrative purposes and are not intended to limit the scope of the messages or information.

[0013] The technical solutions provided by the embodiments of the present application are described in detail below with reference to the drawings, through specific embodiments and application scenarios.

[0014] In an atomic layer deposition (ALD) device, wafer heating mainly adopts two ways: one is radiation heating, which is non-contact heating of the wafer by arranging heating elements inside the reaction chamber and using the principle of heat radiation; the other is conduction heating, which is direct heating of the wafer by integrating heating elements in the wafer carrier base. It should be noted that the second conduction heating method is adopted in the present application, and the temperature uniformity and process stability are ensured by optimizing the base heat conduction path and control algorithm.

[0015] Figure 1 is a structural schematic diagram of a carrier base provided by an exemplary embodiment of the present application. As shown in Figure 1 , ① represents a carrier base for placing a wafer for ALD process; ② represents an outer ring heating wire in the carrier base, which is used to heat the outer ring of the base and conduct heat to the wafer; ③ represents an inner ring heating wire in the carrier base, which is used to heat the inner ring of the base and conduct heat to the wafer; ④ represents a thermocouple K2 for detecting the temperature of the inner ring heating wire, which cuts off the heating when the temperature exceeds the upper limit value T HLimit , mainly for protecting the heating wire. ⑤ represents a thermocouple K3 for detecting the temperature of the outer ring heating wire, which cuts off the heating when the temperature exceeds the upper limit value T HLimit , mainly for protecting the heating wire. ⑥ represents a thermocouple K1 for detecting the temperature of the wafer, which is mainly used as a feedback value for temperature PID control.

[0016] The heating process of the heating control system in the related art is generally as shown in Figure 2 , when receiving the temperature set value SV1 issued by the controller, combining the current temperature value PV1 of the temperature control point fed back by the thermocouple K1 to perform PID adjustment; if the thermocouples K2 / K3 detect that the heating wire temperature PV2 / PV3 does not exceed the upper limit T HLimit during the heating process, the heating wire is controlled to be warmed up, and after the temperature control point is warmed up, the temperature feedback value PV1 of the temperature control point is updated; if the thermocouples K2 / K3 detect that the heating wire temperature PV2 / PV3 exceeds the upper limit T HLimit during the heating process, the heating is cut off and waiting for cooling.

[0017] The heating control scheme in the related art only performs single-stage PID control on the temperature control point, and the temperature of the inner and outer ring heating wires is only used for over-temperature protection. This control method has the following obvious defects: (1) The control precision is limited, only the PID control of the temperature control point, which cannot accurately control the temperature of each heating wire, resulting in a decrease in the overall temperature control precision.

[0018] (2) System stability is insufficient, and the temperature change of the heating wire directly affects the temperature of the temperature control point. If the temperature of the heating wire is only used as over-temperature protection and cannot adjust its working temperature in real time, the temperature of the temperature control point may fluctuate greatly, thereby affecting the stability of the system.

[0019] (3) The temperature rising response speed is slow, and only the temperature control point is controlled by the PID control, which may not be able to respond to the change of the heating wire temperature in time. When the heating wire temperature is abnormal, the system needs a long time to perceive and adjust through the temperature change of the temperature control point, resulting in slow response speed.

[0020] (4) The service life of the heating wire is shortened. The temperature of the heating wire is only used as over-temperature protection, which may not be able to discover and adjust its working state in time. The service life of the heating wire working in a non-optimal state for a long time may be affected, resulting in shortening of the overall service life of the equipment.

[0021] (5) The temperature rising rate cannot be adjusted, the process flexibility is poor, and for some special materials, for example, the ceramic carrier is easy to be damaged by explosion due to the too fast temperature rising rate and uneven temperature.

[0022] In view of the defects of the heating control scheme in the related art, an improved wafer (carrier) heating control system is provided in the embodiments of the present application, please refer to Figure 3 , which is an architecture schematic diagram of the wafer (carrier) heating control system provided by an example embodiment of the present application. As Figure 3 indicated, the wafer heating control system at least includes a controller, a first PID (PID1), a second PID (PID2), a third PID (PID3), an inner ring heating wire K2, an outer ring heating wire K3 and a temperature control point K1. K1, K2 and K3 are thermocouples for detecting the temperature of the corresponding point. Optionally, the wafer heating control system can further include a slope generator.

[0023] Based on the wafer heating control system, a corresponding wafer heating control algorithm is specifically proposed. Please refer to Figure 4 , Figure 4 a flowchart of a wafer heating control method according to an example embodiment of the present application is shown. Taking the case that the method is applied to the wafer heating control system for example. As Figure 4 indicated, the method includes: Step 401, in the i-th heating stage, a first current heating setting value of a target wafer in the current heating stage and a first current temperature value of the target wafer are obtained, i is a positive integer; Step 402, the first current heating setting value and the first current temperature value are processed by the first PID algorithm to obtain a first heating control value; In step 403, a second current heating setting value of the inner ring heating wire and the outer ring heating wire is determined based on the first heating control value, the first current heating setting value, the first current temperature value, and a temperature upper limit value, the temperature upper limit value being a heating temperature upper limit value of the inner ring heating wire and the outer ring heating wire. In step 404, a second current temperature value of the inner ring heating wire and a third current temperature value of the outer ring heating wire are obtained. In step 405, the second current heating setting value and the second current temperature value are processed by a second PID algorithm to obtain a second heating control value. In step 406, the second current heating setting value and the third current temperature value are processed by a third PID algorithm to obtain a third heating control value. In step 407, the inner ring heating wire is controlled based on the second heating control value, and the outer ring heating wire is controlled based on the third heating control value, and heat generated by the inner ring heating wire and the outer ring heating wire is used to conduct to the target wafer to warm up the target wafer. Compared with the original single-stage PID heating control system, the cascade control algorithm is added in the present application: in addition to the first PID of the main loop, two sub-loops (inner ring heating wire + outer ring heating wire) also have corresponding PIDs (second PID and third PID); first, the control amount output by the first PID algorithm of the main loop is multiplied by the upper limit temperature T HLimit The abstract control amount can be converted into an actual temperature reference value, so that the sub-loop setting value has a clear physical meaning. Secondly, the difference (SV1-PV1) between the main loop setting value and the measured value is equivalent to introducing an error compensation term, forming a dynamic feedforward regulation, which can accelerate the response speed of the sub-loop to the deviation of the main loop. The obtained value SV2 is used as the setting value of the inner and outer ring heating wire temperature control sub-loop, and is input into the second PID algorithm and the third PID algorithm of the sub-loop to accurately control the temperature of the inner ring heating wire and the outer ring heating wire.

[0024] Based on the above-mentioned improvement of adding a cascade control algorithm, the wafer heating control process provided by the present application includes: In the i-th heating stage, first, a first current heating setting value of the target wafer in the current heating stage and a first current temperature value of the target wafer are obtained; and the first current heating setting value and the first current temperature value are input into the first PID algorithm (main loop PID), and the first PID algorithm outputs a first heating control value for the inner ring heating wire and the outer ring heating wire according to the error between the setting value (first current heating setting value) and the first current temperature value.

[0025] Secondly, since the heating control of the secondary loop is added, after obtaining the first heating control value, the abstract control amount is converted into the actual temperature reference value of the secondary loop according to the first heating control value, the temperature upper limit value of the inner ring heating wire and the outer ring heating wire in the heating process; and then the difference between the set value (the first current heating set value) and the measured value (the first current temperature value) of the primary loop is superimposed to introduce the error compensation term to obtain the heating set value of the secondary loop. That is, according to the first heating control value, the first current heating set value, the first current temperature value and the temperature upper limit value, the second current heating set value of the inner ring heating wire and the outer ring heating wire is determined, which is the heating set value of the inner ring heating wire and the outer ring heating wire in the current heating stage.

[0026] After obtaining the heating set value of the secondary loop, similar to the primary loop, the second current temperature value of the inner ring heating wire and the third current temperature value of the outer ring heating wire are also needed to be obtained respectively, and the heating control of the inner ring heating wire and the outer ring heating wire is realized through the corresponding PID algorithm. For the inner ring heating wire, the second current temperature value and the second current heating set value of the inner ring heating wire are input into the second PID algorithm, and the second heating control value of the inner ring heating wire is output by the second PID algorithm according to the error between the set value (the second current heating set value) and the second current temperature value; for the outer ring heating wire, the third current temperature value and the second current heating set value of the outer ring heating wire are input into the third PID algorithm, and the third heating control value of the outer ring heating wire is output by the third PID algorithm according to the error between the set value (the second current heating set value) and the third current temperature value.

[0027] Finally, after obtaining the heating control value for the secondary loop, the heating control of the heating wire can be realized based on the heating control value: the heating control of the inner ring heating wire based on the second heating control value, and the heating control of the outer ring heating wire based on the third heating control value. The heat generated by the inner ring heating wire and the outer ring heating wire can be transmitted to the target wafer through the carrier to warm up the target wafer.

[0028] It should be noted that in the i-th heating stage, the thermocouple K1 used to detect the temperature of the wafer will detect the new current temperature value of the target wafer, and steps 401 to 404 will be executed repeatedly until the target temperature set value is reached and the heating is stopped before the current temperature value reaches the target temperature set value. For example, after the i-th heating stage, the current temperature value of the target wafer is the i-th current temperature value, and the i-th current temperature value does not reach the target temperature set value, the i+1-th heating stage is executed, and the i-th current temperature value is determined as the first current temperature value in the current heating stage. Similarly, the second current temperature value of the inner ring heating wire and the third current temperature value of the outer ring heating wire are also updated.

[0029] For example, the principles of the first PID algorithm, the second PID algorithm and the third PID algorithm can refer to the PID control (Proportional Integral Derivative control) algorithm in the related art, and details are not described herein.

[0030] Optionally, the first current heating set value can be a target temperature rise set value of the target wafer; or the first current heating set value is a set value of the current heating stage, which is less than or equal to the target temperature rise set value.

[0031] For the acquisition method of multiple temperature values in the wafer heating control algorithm: the first current temperature value is collected by a thermocouple K1 arranged on the stage base; the second current temperature value is collected by a thermocouple K2 arranged on the stage base; and the third current temperature value is collected by a thermocouple K3 arranged on the stage base.

[0032] For example, in the calculation of the second current heating set value, the specific calculation formula can be as shown in formula (1): SV2=Out1*T HLimit + (SV1-PV1) (1) Wherein, SV2 is the second current heating set value, Out1 is the first heating control value, which can be a percentage control amount, T HLimit is a temperature upper limit value, SV1 is the first current heating set value, and PV1 is the first current temperature value. As can be seen from formula (1), after the first PID algorithm outputs Out1, Out1 is multiplied by the temperature upper limit value (T HLimit ) of the inner and outer heating wires, which can convert the abstract control amount into a specific temperature limit value to avoid the inner and outer heating wires from exceeding the temperature upper limit value. Moreover, on this basis, the difference (SV1-PV1) between the main loop set value and the measured value is superimposed, so that when the wafer temperature and the set value differ greatly, the greater the difference, the greater the set value SV2 of the secondary loop, and the greater the heating control value output by the secondary loop PID algorithm, which can control the inner and outer heating wires to heat faster, thereby accelerating the response speed of the secondary loop to the deviation of the main loop. When the wafer temperature and the set value differ less, the difference tends to be 0, at which time the secondary loop set value is mainly determined by the output of the first PID algorithm, which is equivalent to entering a "fine tuning mode" to reduce the risk of overshoot. The integral term of the main loop can gradually eliminate the steady-state error, while the proportional action of the secondary loop is enhanced to improve the tracking accuracy, forming a complementary regulation mechanism.

[0033] Please refer to Figure 5 , which is a flowchart of a wafer heating control algorithm provided by an example embodiment of the present application. As shown in Figure 5As shown, the target wafer heating set value SV1 (first current heating set value) is received, and the temperature feedback value PV1 (first current temperature value) of the temperature control point is obtained; and the first PID algorithm PID1 of the main loop outputs Out1 (first heating control value) based on the error between the set value SV1 and the measured value PV1; the output Out1 of the main loop is multiplied by the temperature upper limit value T HLimit The difference (SV1-PV1) between the set value and the measured value of the main loop is superimposed to obtain the heating set value SV2 (second current heating set value) of the secondary loop; then, the inner ring temperature feedback value PV2 (second current temperature value of the inner ring heating wire) and the outer ring temperature feedback value PV3 (third current temperature value of the outer ring heating wire) are obtained, and the second PID algorithm PID2 outputs Out2 (second heating control value) based on the error between the set value SV2 and the measured value PV2 to control the inner ring heating wire to heat up; and the third PID algorithm PID3 outputs Out3 (third heating control value) based on the error between the set value SV2 and the measured value PV3 to control the outer ring heating wire to heat up; finally, the heat generated by the inner ring heating wire and the outer ring heating wire is used to conduct to the target wafer to heat up the target wafer, that is, to heat up the temperature control point; the temperature control point continues to feed back new PV1 to the main loop PID1, and the algorithm flowchart is executed in a loop until the target wafer heating value set value is reached.

[0034] In summary, the wafer heating control method provided by the embodiments of the present application is as follows: for each heating stage, after the first PID algorithm of the main loop outputs the first heating control value according to the first current heating set value and the first current temperature value, the abstract control quantity is converted into the actual temperature reference value of the secondary loop according to the first heating control value and the temperature upper limit value of the inner ring heating wire and the outer ring heating wire during heating; the difference between the set value (first current heating set value) and the measured value (first current temperature value) of the main loop is superimposed to introduce an error compensation term to obtain the second current heating set value of the secondary loop; so as to accurately control the inner ring heating wire and the outer ring heating wire to heat up according to the error between the second current heating set value and the current temperature value of the heating wire (inner and outer ring heating wires); moreover, the introduction of the error compensation term can also form a dynamic feedforward adjustment to accelerate the response speed of the secondary loop to the deviation of the main loop. In addition, the main loop focuses on overall temperature trend control (slow large inertia process), and the secondary loop adjusts the heating power based on the set value generated by the output of the main loop (fast small inertia process) to form a time scale separation control architecture. In addition, the addition of the main loop error term (SV1-PV1) can reflect the system disturbance in real time, and the secondary loop can offset the influence of such interference on the main parameters in advance through rapid adjustment to reduce the control pressure of the main loop. Compared with the traditional step set, the response of the system to the disturbance is smoother, and the steady-state recovery time is shortened.

[0035] At the beginning of temperature rise, because the temperature difference between the wafer and the set value is large, the inner and outer ring heating wires may start to heat up quickly, causing the temperature rise rate of the carrier to be too fast. For some special material carriers, such as ceramic carriers, the temperature rise rate is too fast, which can cause the carrier to crack due to uneven temperature. Moreover, the temperature rise is too fast, which can also affect the service life of the heating wire. Therefore, in order to control the temperature rise rate, compared with the original heating control scheme, a slope generator is introduced to increase the temperature rise rate control logic to realize accurate control of the temperature rise rate.

[0036] Please refer to Figure 6 , Figure 6 A flowchart of another wafer heating control method according to an example embodiment of the present application is shown. Taking the case where the method is applied to a wafer heating control system for example, the method includes the following steps. Figure 6 Step 601: In the ith heating stage, a first current temperature value of the target wafer is obtained. Wherein, the first current temperature value of the target wafer is collected by the thermocouple K1 at the temperature control point. Generally, the first current temperature value of the target wafer will gradually increase during the entire temperature rise process until it reaches the pre-set target temperature rise set value. For example, the first current temperature value obtained in the (i+1)th heating stage is higher than the first current temperature value obtained in the ith heating stage.

[0037] Step 602: Obtain the set temperature rise rate, temperature rise time interval, current temperature rise adjustment coefficient and target temperature rise set value of the target wafer in the current heating stage. As shown in Figure 3 In order to realize accurate control of the temperature rise rate, a slope generator is added to the wafer heating control system. The slope generator can convert the set target temperature rise set value into a slope signal that increases linearly with time. That is, instead of directly inputting the target temperature rise set value into the main loop PID (first PID algorithm), the first current heating set value in each heating stage is different and will increase linearly from the initial value to the target temperature rise set value.

[0038] For example, the calculation formula of the first current heating set value corresponding to each heating stage can be as shown in formula (2): SV11 = PV Init + C * R Set * Δt ≤ SV1(2) Wherein, PVInit is the initial temperature value, C is the dynamic adjustment coefficient (current temperature rise adjustment coefficient), which is 1 by default, R Set ​For the set temperature ramping rate, Δt is the time variation (i.e. the temperature ramping interval). It is noted that when i is 1, i.e. the first heating stage (at the beginning of heating), PVInit is the initial temperature value of the target wafer, and when i is greater than 1, i.e. the subsequent heating stage, PVInit=PV1 is the first current temperature value of the target wafer.

[0039] As can be seen from equation (2), when calculating the first current heating set value of the i-th heating stage, the slope generator needs to obtain the first current temperature value of the target wafer, the set temperature ramping rate, the temperature ramping interval, the current temperature ramping adjustment coefficient and the target temperature set value, and then calculate the first current heating set value of the current heating stage based on the slope generator function equation (2).

[0040] The set temperature ramping rate is set by the user according to the process requirements.

[0041] Optionally, in order to avoid the temperature from ramping up too fast, when setting the set temperature ramping rate, it is also necessary to ensure that the set temperature ramping rate is less than the maximum temperature ramping rate (i.e. the maximum allowed temperature ramping rate), i.e. R Set Max The calculation process of the maximum temperature ramping rate can include the following steps S10 to S13.

[0042] Step S10, without using the slope generator function, the target time length required for the temperature of the target wafer to ramp up from the initial temperature to the target temperature set value is obtained.

[0043] Step S12, based on the initial temperature, the target temperature set value and the target time length, the maximum temperature ramping rate is determined.

[0044] Step S13, based on the maximum temperature ramping rate, the set temperature ramping rate is determined, and the set temperature ramping rate is less than the maximum temperature ramping rate.

[0045] Without using the slope generator function, the system response curve during the period when the temperature of the target wafer is controlled to ramp up from the initial temperature to the target temperature set value is obtained, the system response curve describes the change of the wafer temperature at different time points during the period when the temperature is ramped up from the initial temperature to the target temperature set value. From the system response curve, the total target time length required for the temperature to ramp up from the initial temperature to the target temperature set value is obtained, and the temperature ramping difference (i.e. the target temperature set value minus the initial temperature) within the target time length is obtained, and then the maximum temperature ramping rate is determined according to the temperature ramping difference and the target time length. After the maximum temperature ramping rate is determined, the user can select the set temperature ramping rate based on the maximum temperature ramping rate according to the process requirements, and ensure that the set temperature ramping rate is less than the maximum temperature ramping rate.

[0046] ​At step 603, the set temperature rising rate, the temperature rising time interval, the current temperature rising adjustment coefficient, the target temperature rising set value and the first current temperature value are processed by a ramp generator function to determine the first current heating set value of the target wafer in the current heating stage.

[0047] Optionally, when calculating the first current heating set value, the first current heating set value needs to satisfy SV11≤SV1.

[0048] It should be noted that when the ramp generator function is not used, the first current heating set value is SV1, i.e., the target temperature rising set value of the target wafer; when the ramp generator function is used, the first current heating value is SV11, which is less than or equal to SV1, and SV11 linearly increases with time.

[0049] In one possible implementation, the set temperature rising rate, the temperature rising time interval, the current temperature rising adjustment coefficient, the target temperature rising set value and the first current temperature value obtained are substituted into formula (2) to calculate the first current heating set value of the target wafer in the current heating stage by the ramp generator function.

[0050] Since there may be a deviation between the actual temperature rising rate and the set temperature rising rate, in order to compensate for the deviation, the actual temperature rising rate is also calculated regularly, and the current temperature rising adjustment coefficient is dynamically adjusted when the deviation is too large to dynamically correct the set temperature rising rate. For example, the process of dynamically adjusting the current temperature rising adjustment coefficient (i.e., obtaining the current temperature rising adjustment coefficient of the target wafer in the current heating stage) can include the following steps S20 to S23.

[0051] At step S20, the actual temperature rising rate in a preset time period before the current heating stage is obtained. Specifically, when calculating the actual temperature rising rate, a preset time period can be set, and the temperature rising temperature difference in the preset time period before the current heating stage is obtained, and then the actual temperature rising rate in the preset time period before the current heating stage is determined based on the temperature rising temperature difference and the preset time length corresponding to the preset time period.

[0052] For example, the calculation formula of the actual temperature rising rate can be as shown in formula (3): R Ac t = (PV1 - PV Init )÷Δt(3) Wherein, R Ac t represents the actual temperature rising rate, (PV1 - PV Init ) represents the temperature rising temperature difference of the preset time period, and Δt is the preset time length of the preset time period. It should be noted that the preset time period can also be the temperature rising temperature difference of the target wafer from the initial temperature value PV Inita time period for increasing the temperature to the first current temperature value PV1.

[0053] In step S21, a rate deviation between the actual temperature increasing rate and the set temperature increasing rate is determined. In order to avoid unnecessary dynamic correction, the rate deviation between the actual temperature increasing rate and the set temperature increasing rate is calculated, and the current temperature increasing adjustment coefficient is dynamically adjusted again when the rate deviation is greater than the deviation threshold.

[0054] In step S23, if the rate deviation is greater than the deviation threshold, the current temperature increasing adjustment coefficient is determined based on the set temperature increasing rate and the actual temperature increasing rate.

[0055] In step S23, if the rate deviation is greater than the deviation threshold, the current temperature increasing adjustment coefficient is determined based on the set temperature increasing rate and the actual temperature increasing rate.

[0056] For example, the calculation formula of the current temperature increasing adjustment coefficient can be shown in formula (4): C = R Set ÷ R Act (4) Wherein, R Set is the set temperature increasing rate, and R Act is the actual temperature increasing rate; in general scenarios, the actual temperature increasing rate is less than the set temperature increasing rate, so by dynamically adjusting the temperature increasing adjustment coefficient, the set temperature increasing rate can be increased, so that the actual temperature increasing rate is more close to the original set temperature increasing rate.

[0057] Optionally, if the rate deviation is less than or equal to the deviation threshold, the default temperature increasing adjustment coefficient can be determined as the current temperature increasing adjustment coefficient, and the default temperature increasing adjustment coefficient is 1.

[0058] In step 604, the first current heating set value and the first current temperature value are processed by the first PID algorithm to obtain a first heating control value. In step 605, based on the first heating control value, the first current heating set value, the first current temperature value and a temperature upper limit value, a second current heating set value of the inner and outer heating wires is determined, and the temperature upper limit value is a heating temperature upper limit value of the inner and outer heating wires. In step 606, a second current temperature value of the inner heating wire and a third current temperature value of the outer heating wire are obtained. In step 607, the second current heating set value and the second current temperature value are processed by the second PID algorithm to obtain a second heating control value. In step 608, the second current heating set value and the third current temperature value are processed by the third PID algorithm to obtain a third heating control value. Step 609, heating control is performed on the inner ring heating wire based on a second heating control value, and heating control is performed on the outer ring heating wire based on a third heating control value, and heat generated by the inner ring heating wire and the outer ring heating wire is used to conduct to the target wafer to warm up the target wafer. The embodiments of steps 604 to 609 can refer to steps 402 to 407, and this embodiment will not be described here.

[0059] Based on Figure 3 The complete heating control process provided by the wafer (stage) heating control system described in the application can be: receiving the target wafer target temperature setting value SV1 and the set temperature rate R Set and the first current temperature value, to calculate the set value SV11 (the first current heating set value) of the target wafer in this heating stage based on the set temperature rate, the temperature interval, the current temperature adjustment coefficient, the target temperature setting value and the first current temperature value; and output Out1 (the first heating control value) based on the error between the set value SV11 and the measured value PV1 through the main loop PID1 (the first PID algorithm); multiply the output Out1 of the main loop by the temperature upper limit value T HLimit , superimpose the difference (SV11-PV1) between the set value and the measured value of the main loop, and obtain the heating set value SV2 (the second current heating set value) of the secondary loop; then, obtain the inner ring temperature feedback value PV2 (the second current temperature value of the inner ring heating wire) and the outer ring temperature feedback value PV3 (the third current temperature value of the outer ring heating wire), and output Out2 (the second heating control value) based on the error between the set value SV2 and the measured value PV2 through the secondary loop PID2 (the second PID algorithm) to control the temperature of the inner ring heating wire; and output Out3 (the third heating control value) based on the error between the set value SV2 and the measured value PV3 through the secondary loop PID3 (the third PID algorithm) to control the temperature of the outer ring heating wire, finally, heat generated by the inner ring heating wire and the outer ring heating wire is used to conduct to the target wafer to warm up the target wafer, that is, to warm up the temperature control point; the temperature control point continues to feed back new PV1 to the main loop PID1, and the algorithm flowchart is executed in a loop until the target wafer temperature setting value is set.

[0060] ​In this embodiment, by introducing a ramp generator, the output of the heating set value changes linearly, which can realize precise control of the heating rate, reduce thermal stress impact, avoid micro-cracks and thermal fatigue caused by temperature mutation, and prolong the service life of the device. Moreover, for processes that require staged heating, the segmented slope rate can be used to achieve precise control of the heating curve, improving process compatibility. In addition, using a ramp generator can reduce the risk of integral saturation and reduce overshoot caused by temperature overshoot.

[0061] Please refer to Figure 7 , which is a structure diagram of a wafer heating control device provided by the embodiment of the application. The device 700 comprises: The first acquisition module 701 is configured to acquire, in the i-th heating stage, a first current heating set value of a target wafer in the current heating stage and a first current temperature value of the target wafer, i being a positive integer; The first control module 702 is configured to process the first current heating set value and the first current temperature value by using a first PID algorithm to obtain a first heating control value; The first determination module 703 is configured to determine a second current heating set value of an inner ring heating wire and an outer ring heating wire based on the first heating control value, the first current heating set value, the first current temperature value, and a temperature upper limit value, the temperature upper limit value being a heating temperature upper limit value of the inner ring heating wire and the outer ring heating wire; The second acquisition module 704 is configured to acquire a second current temperature value of the inner ring heating wire and a third current temperature value of the outer ring heating wire; The second control module 705 is configured to process the second current heating set value and the second current temperature value by using a second PID algorithm to obtain a second heating control value; The third control module 706 is configured to process the second current heating set value and the third current temperature value by using a third PID algorithm to obtain a third heating control value; The heating control module 707 is configured to perform heating control on the inner ring heating wire based on the second heating control value and perform heating control on the outer ring heating wire based on the third heating control value, and heat generated by the inner ring heating wire and the outer ring heating wire is used to conduct to the target wafer to heat up the target wafer.

[0062] Optionally, the first acquisition module 701 is further configured to: acquire a set heating rate, a heating time interval, a current heating adjustment coefficient of the target wafer in the current heating stage, and a target heating set value of the target wafer; The ramp generator function is used to process the set temperature rising rate, the temperature rising time interval, the current temperature rising adjustment coefficient, the target temperature rising set value and the first current temperature value, to determine the first current heating set value of the target wafer in the current heating stage.

[0063] Optionally, the first obtaining module 701 is further configured to: obtain an actual temperature rising rate in a preset time period before the current heating stage; determine a rate deviation between the actual temperature rising rate and the set temperature rising rate; if the rate deviation is greater than a deviation threshold, determine the current temperature rising adjustment coefficient based on the set temperature rising rate and the actual temperature rising rate.

[0064] Optionally, the first obtaining module 701 is further configured to: obtain a temperature rising difference in the preset time period before the current heating stage; determine the actual temperature rising rate in the preset time period before the current heating stage based on the temperature rising difference and a preset time length corresponding to the preset time period.

[0065] Optionally, the apparatus further includes: a third obtaining module configured to obtain, without using the ramp generator function, a target time length required for rising the temperature of the target wafer from an initial temperature to a target temperature rising set value; a second determining module configured to determine a maximum temperature rising rate based on the initial temperature, the target temperature rising set value and the target time length; a third determining module configured to determine the set temperature rising rate based on the maximum temperature rising rate, the set temperature rising rate being less than the maximum temperature rising rate.

[0066] Optionally, without using the ramp generator function, the first current heating set value is the target temperature rising set value.

[0067] Optionally, a calculation formula of the second current heating set value is: SV2=Out1*T HLimit +(SV1-PV1) wherein the SV2 is the second current heating set value, the Out1 is the first heating control value, the T HLimit is the temperature upper limit value, the SV1 is the first current heating set value, and the PV1 is the first current temperature value.

[0068] The exemplary embodiments of the present application also provide an electronic device, comprising: at least one processor; and a memory connected to the at least one processor in communication. The memory stores a computer program capable of being executed by the at least one processor, and the computer program, when executed by the at least one processor, is configured to cause the electronic device to perform the wafer heating control method according to the embodiments of the present application.

[0069] The exemplary embodiments of the present application also provide a non-transitory computer readable storage medium storing a computer program, wherein the computer program, when executed by a processor of a computer, is configured to cause the computer to perform the wafer heating control method according to the embodiments of the present application.

[0070] The exemplary embodiments of the present application also provide a computer program product comprising a computer program, wherein the computer program, when executed by a processor of a computer, is configured to cause the computer to perform the wafer heating control method according to the embodiments of the present application.

[0071] Reference Figure 8 will now be described. The components, their connections and relationships, and their functions, as described herein, are meant to be examples only, and are not intended to limit the implementations of the present application described and / or claimed in this document.

[0072] As shown in Figure 8 , the electronic device 800 includes a computing unit 801, which can perform various appropriate actions and processes according to a computer program stored in a ROM 802 or a computer program loaded into a RAM 803 from a storage unit 808. In the RAM 803, various programs and data required for the operation of the electronic device 800 can also be stored. The computing unit 801, the ROM 802, and the RAM 803 are connected to each other through a bus 804. An I / O interface 805 is also connected to the bus 804.

[0073] Multiple components in electronic device 800 are connected to I / O interface 805, including: input unit 806, output unit 807, storage unit 808, and communication unit 809. Input unit 806 can be any type of device capable of inputting information to electronic device 800. Input unit 806 can receive input digital or character information and generate key signal inputs related to user settings and / or function control of electronic device. Output unit 807 can be any type of device capable of presenting information and may include, but is not limited to, a display, speaker, video / audio output terminal, vibrator, and / or printer. Storage unit 808 may include, but is not limited to, disk and optical disk. Communication unit 809 allows electronic device 800 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks, and may include, but is not limited to, modems, network cards, infrared communication devices, wireless communication transceivers, and / or chipsets, such as Bluetooth devices, WiFi devices, WiMax devices, cellular communication devices, and / or the like.

[0074] The computing unit 801 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 801 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 801 performs the various methods and processes described above. For example, in some embodiments, Figure 4 , Figure 6 The method shown can be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as storage unit 808. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 800 via ROM 802 and / or communication unit 809. In some embodiments, computing unit 801 can be configured to execute by any other suitable means (e.g., by means of firmware). Figure 4 , Figure 6 The method shown.

[0075] The program code used to implement the methods of this application may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0076] In the context of this application, a machine-readable medium can be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine- readable medium can include but is not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the machine-readable storage medium will include one or more lines of electrical connections, portable computer disks, hard disk drives, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or Flash memory), optical fibers, portable compact disc read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0077] As used in this application, the terms "machine-readable medium" and "computer- readable medium" refer to any computer program product, apparatus and / or device (e.g., magnetic discs, optical disks, memory, Programmable Logic Devices (PLDs)) used to provide machine instructions and / or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal that can be used to provide machine instructions and / or data to a programmable processor.

[0078] To provide for interaction with a user, the systems and techniques described here can be implemented on a computer having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user and a keyboard and a pointing device (e.g., a mouse or a trackball) by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0079] The systems and techniques described here can be implemented in a computing system that includes a back end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front end component (e.g., a user computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (LAN), a wide area network (WAN), and the Internet.

[0080] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.

Claims

1. A wafer heating control method, characterized in that, The method includes: In the i-th heating stage, the first current heating setting value of the target wafer and the first current temperature value of the target wafer in this heating stage are obtained, where i is a positive integer; The first heating control value is obtained by processing the first current heating setpoint and the first current temperature value using the first PID algorithm. Based on the first heating control value, the first current heating setting value, the first current temperature value, and the upper temperature limit value, a second current heating setting value for the inner heating wire and the outer heating wire is determined, wherein the upper temperature limit value is the upper limit value of the heating temperature of the inner heating wire and the outer heating wire; Obtain the second current temperature value of the inner heating wire and the third current temperature value of the outer heating wire; The second heating control value is obtained by processing the second current heating setpoint and the second current temperature value using the second PID algorithm. The third heating control value is obtained by processing the second current heating setpoint and the third current temperature value using a third PID algorithm. The inner heating wire is heated based on the second heating control value, and the outer heating wire is heated based on the third heating control value. The heat generated by the inner and outer heating wires is conducted to the target wafer to raise the temperature of the target wafer.

2. The method according to claim 1, characterized in that, The process of obtaining the first current heating setting value of the target wafer in this heating stage includes: The set heating rate, heating time interval, current heating adjustment coefficient, and target heating set value of the target wafer are obtained during this heating stage. The slope generator function processes the set heating rate, the heating time interval, the current heating adjustment coefficient, the target heating set value, and the first current temperature value to determine the first current heating set value of the target wafer in this heating stage.

3. The method according to claim 2, characterized in that, The step of obtaining the current temperature adjustment coefficient of the target wafer during this heating stage includes: Obtain the actual heating rate within a preset time period prior to this heating phase; Determine the rate deviation between the actual heating rate and the set heating rate; If the rate deviation is greater than the deviation threshold, the current temperature adjustment coefficient is determined based on the set heating rate and the actual heating rate.

4. The method according to claim 3, characterized in that, The process of obtaining the actual temperature rise rate within a preset time period prior to the current heating phase includes: Obtain the temperature difference during the preset time period prior to this heating phase; Based on the temperature difference and the preset duration corresponding to the preset time period, the actual heating rate within the preset time period before this heating stage is determined.

5. The method according to claim 2, characterized in that, The method further includes: Without using the ramp generator function, obtain the target time required to raise the temperature of the target wafer from the initial temperature to the target temperature setting value; The maximum heating rate is determined based on the initial temperature, the target heating setpoint, and the target duration. The set heating rate is determined based on the maximum heating rate, and the set heating rate is less than the maximum heating rate.

6. The method according to claim 1, characterized in that, Without using the ramp generator function, the first current heating setting is the target temperature rise setting.

7. The method according to any one of claims 1 to 6, characterized in that, The formula for calculating the second current heating setpoint is: SV2=Out1*T HLimit +(SV1-PV1) Wherein, SV2 is the second current heating setting value, Out1 is the first heating control value, and T... HLimit The upper limit of temperature is defined as SV1, the first current heating setting value is defined as PV1, and the first current temperature value is defined as PV1.

8. A wafer heating control device, characterized in that, The device includes: The first acquisition module is used to acquire the first current heating setting value of the target wafer and the first current temperature value of the target wafer in the current heating stage during the i-th heating stage, where i is a positive integer; The first control module is used to process the first current heating setpoint and the first current temperature value through a first PID algorithm to obtain a first heating control value; The first determining module is used to determine the second current heating setting value of the inner ring heating wire and the outer ring heating wire based on the first heating control value, the first current heating setting value, the first current temperature value and the upper limit temperature value, wherein the upper limit temperature value is the upper limit value of the heating temperature of the inner ring heating wire and the outer ring heating wire; The second acquisition module is used to acquire the second current temperature value of the inner ring heating wire and the third current temperature value of the outer ring heating wire; The second control module is used to process the second current heating setpoint and the second current temperature value through a second PID algorithm to obtain a second heating control value; The third control module is used to process the second current heating setpoint and the third current temperature value through a third PID algorithm to obtain a third heating control value; A heating control module is used to control the heating of the inner heating wire based on the second heating control value and to control the heating of the outer heating wire based on the third heating control value. The heat generated by the inner and outer heating wires is conducted to the target wafer to raise the temperature of the target wafer.

9. An electronic device, comprising: The processor and the memory that stores the program; The program includes instructions that, when executed by the processor, cause the processor to perform the wafer heating control method according to any one of claims 1-7.

10. A non-transitory computer-readable storage medium storing computer instructions, wherein, The computer instructions are used to cause the computer to execute the wafer heating control method according to any one of claims 1-7.

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