A rapid thermal processing device and a temperature control method thereof

Abstract

The present invention provides a rapid thermal processing equipment and a temperature control method thereof, the equipment comprising: multiple groups of wafer heating elements, different groups of wafer heating elements correspond to different areas of a wafer to be heated; multiple groups of wafer temperature sensors, different groups of wafer temperature sensors are used to measure the wafer temperature corresponding to different areas; a support ring heating element, used to heat the support ring; a support ring temperature sensor, used to measure the temperature of the support ring; a heating control device, used to determine the wafer heating rate of different areas according to the wafer temperature corresponding to different areas, and adjust the heating power of the corresponding group of wafer heating elements according to the wafer heating rate of different areas, and also used to adjust the heating power of the support ring heating element based on the difference between the temperature of the support ring and the temperature of the wafer to be heated, until the temperature of the wafer to be heated reaches a first temperature threshold. The present invention can reduce the warping deformation of the wafer and ensure the equipment production capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to a rapid thermal processing device and a temperature control method thereof. Background Art

[0002] In the semiconductor manufacturing process, the rapid thermal processing (RTP) process is used to quickly and uniformly heat semiconductor workpieces such as wafers. It is usually used in the activation and diffusion of dopants after ion implantation, the annealing after the formation of metal silicide, and the annealing of the gate oxide layer.

[0003] In the rapid thermal processing process, the wafer is placed in a closed reaction chamber and heated using a specific heat source and a preset heating program to quickly reach the desired temperature. In terms of temperature control, the process temperature range of rapid thermal processing equipment is usually between 180℃ and 1200℃, which is a high-temperature process equipment. The number of wafers per hour is an important parameter in rapid thermal processing equipment, which directly affects the actual production capacity of the equipment.

[0004] In practical applications, the rapid thermal processing of wafers will go through open-loop heating and closed-loop heating processes. In the open-loop heating process, the wafer is heated from a constant power to a lower temperature setting value, the system will enter a relatively stable and controllable state, and the wafer heating process will enter a closed-loop control to heat the wafer to a higher temperature setting value. Since semiconductor workpieces, such as different materials in wafers (such as Si, SiO2, SiN, etc.), have different absorption coefficients of light, when the single-sided radiation method is used to heat the front of the semiconductor workpiece, the wafer absorption and heating rate is different at the same heating power.

[0005] Currently, in the open-loop heating step, the output power of the heating lamp group is usually set to a constant value, so the temperatures of different material areas inside the wafer will be different under the same heating time. If the temperature difference between different parts inside the wafer is too large, the wafer will warp or even break.

[0006] In addition, after the open-loop heating is completed, the wafer will be placed on a support ring for closed-loop heating. When the wafer begins to contact the support ring, if the temperature difference between the wafer and the support ring is too large, it will cause the wafer to warp or even jump. The equipment will issue an alarm and stop running, thereby affecting the actual production capacity of the equipment. Summary of the invention

[0007] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a rapid thermal processing equipment and a temperature control method thereof, so as to reduce the warping deformation of the wafer and ensure the equipment production capacity.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a rapid thermal processing device, comprising:

[0010] Multiple groups of wafer heating elements, different groups of wafer heating elements correspond to different areas of the wafer to be heated, and the heating power of each group of wafer heating elements can be controlled separately;

[0011] A plurality of groups of wafer temperature sensors, wherein different groups of wafer temperature sensors are used to measure the wafer temperatures corresponding to the different areas;

[0012] A support ring, used for supporting the wafer to be heated after the temperature of the wafer to be heated reaches a preset first temperature threshold;

[0013] a support ring heating element, for heating the support ring;

[0014] a support ring temperature sensor, used to measure the temperature of the support ring; and

[0015] The heating control device is used, on the one hand, to determine the wafer heating rates of the different areas according to the wafer temperatures corresponding to the different areas, and to adjust the heating powers of the corresponding groups of wafer heating elements according to the wafer heating rates of the different areas, so that the wafer heating rates of the different areas are all maintained within a predetermined wafer heating rate range. The heating control device is used, on the other hand, to adjust the heating power of the support ring heating element based on the difference between the temperature of the support ring and the temperature of the wafer to be heated, so that the difference between the temperature of the support ring and the temperature of the wafer to be heated is less than a preset temperature difference threshold, until the temperature of the wafer to be heated reaches the first temperature threshold.

[0016] Further, each group of the wafer heating elements is respectively arranged above the wafer to be heated around the central axis of the wafer to be heated;

[0017] Each group of wafer temperature sensors is respectively arranged below the wafer to be heated around the central axis of the wafer to be heated.

[0018] Furthermore, the support ring heating element is arranged above the support ring, and the support ring temperature sensor is arranged below the support ring.

[0019] Furthermore, the device also includes supporting pins; wherein, before the temperature of the wafer to be heated reaches the first temperature threshold, the wafer to be heated is supported by the supporting pins; after the temperature of the wafer to be heated reaches the first temperature threshold, the supporting pins drive the wafer to be heated to be placed on the supporting ring.

[0020] Furthermore, the wafer heating element and the support ring heating element are both heating lamps.

[0021] Furthermore, the wafer temperature sensor and the support ring temperature sensor are both pyrometers.

[0022] Furthermore, when the wafer to be heated is carried on the support ring, the heating control device is also used to perform closed-loop control on the heating power of each group of the wafer heating elements based on the wafer temperatures corresponding to the different areas.

[0023] In a second aspect, the present invention provides a temperature control method for a rapid thermal processing device, the rapid thermal processing device comprising a plurality of groups of wafer heating elements arranged corresponding to different regions of a wafer to be heated, a plurality of groups of wafer temperature sensors for measuring the wafer temperatures corresponding to the different regions, a support ring for supporting the wafer to be heated after the temperature of the wafer to be heated reaches a preset first temperature threshold, a support ring heating element for heating the support ring, and a support ring temperature sensor for measuring the temperature of the support ring; wherein the temperature control method comprises:

[0024] Control the wafer heating element and the support ring heating element to heat for a predetermined time at a preset heating power;

[0025] Determining the wafer heating rates of the different regions according to the wafer temperatures corresponding to the different regions, and adjusting the heating powers of the corresponding groups of wafer heating elements according to the wafer heating rates of the different regions, so that the wafer heating rates of the different regions are all maintained within a predetermined wafer heating rate range;

[0026] The heating power of the support ring heating element is adjusted based on the difference between the temperature of the support ring and the temperature of the wafer to be heated, so that the difference between the temperature of the support ring and the temperature of the wafer to be heated is less than a preset temperature difference threshold, until the temperature of the wafer to be heated reaches the first temperature threshold.

[0027] Furthermore, before adjusting the heating power of the support ring heating element based on the difference between the temperature of the support ring and the temperature of the wafer to be heated, the temperature control method further includes:

[0028] The heating rate of the support ring is determined according to the temperature of the support ring, and the heating power of the support ring heating element is adjusted according to the heating rate of the support ring, so that the heating rate of the support ring is maintained within a predetermined range of the heating rate of the support ring.

[0029] Further, after the wafer to be heated is supported on the support ring, the temperature control method further comprises:

[0030] Based on the wafer temperatures corresponding to the different areas, the heating power of each group of the wafer heating elements is controlled in a closed loop.

[0031] By adopting the above technical solution, the present invention has the following beneficial effects:

[0032] On the one hand, the present invention determines the wafer heating rates of different areas according to the wafer temperatures corresponding to the different areas, and adjusts the heating powers of the corresponding groups of wafer heating elements according to the wafer heating rates of the different areas, so that the wafer heating rates of the different areas are all maintained within a predetermined wafer heating rate range, thereby avoiding warping caused by excessive temperature differences in different areas of the wafer; on the other hand, the heating power of the support ring heating element is adjusted based on the difference between the temperature of the support ring and the temperature of the wafer to be heated, so that the difference between the temperature of the support ring and the temperature of the wafer to be heated is less than a preset temperature difference threshold, thereby avoiding warping caused by excessive temperature differences between the wafer and the support ring, thereby reducing the frequency of process failures and achieving the purpose of improving process stability and production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the local structure of the rapid thermal processing equipment of Example 1 of the present invention when the wafer is supported by the support pins;

[0034] Figure 2 It is a schematic diagram of the local structure of the rapid thermal processing equipment of Example 1 of the present invention when the wafer is supported by the support ring;

[0035] Figure 3 Schematic diagram of the distribution of each group of wafer temperature sensors along different radii in Example 1 of the present invention;

[0036] Figure 4 This is a flow chart of the temperature control method of Example 2 of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0038] The terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The singular forms "a", "the" and "the" used in the present disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0039] As mentioned above, the rapid thermal processing of wafers will go through open-loop heating and closed-loop heating processes. In the open-loop heating process, the wafer is heated to a lower temperature setting value at a constant power. Since different materials in the wafer have different absorption coefficients of light, the heating rates of different material areas will be different at the same heating power. If the temperature difference between different areas is too large, the wafer will warp or even break.

[0040] In addition, after the open-loop heating is completed, the wafer will be placed on a support ring for closed-loop heating. When the wafer begins to contact the support ring, if the temperature difference between the wafer and the support ring is too large, it will cause the wafer to warp or even jump. The equipment will issue an alarm and stop running, thereby affecting the actual production capacity of the equipment.

[0041] Therefore, in order to reduce wafer warping deformation, increase the number of wafers processed per hour by rapid thermal processing equipment, reduce equipment downtime, and ensure the actual production capacity of the equipment, the present invention provides an improved rapid thermal processing equipment and a temperature control method thereof.

[0042] Example 1

[0043] This embodiment provides a rapid thermal processing device, such as Figure 1-Figure 3 As shown, the device includes multiple groups of wafer heating elements 1, multiple groups of wafer temperature sensors 2, support pins 3, support rings 4, support ring heating elements 5 and support ring temperature sensors 6 arranged in the reaction chamber. At the same time, the device also includes a heating control device (not shown) connected to the wafer heating elements 1, the wafer temperature sensors 2, the support ring heating elements 5 and the support ring temperature sensors 6.

[0044] In this embodiment, after the wafer 10 to be heated is transferred to the reaction chamber, it is placed on the support pins 3 so that the wafer is located directly above the support ring 4. The support pins 3 are liftable support pins. When the temperature of the wafer 10 to be heated subsequently reaches the first temperature threshold, the support pins 3 drive the wafer 10 to be heated to descend so that it is placed on the support ring 4. The support ring 4 starts to rotate, and at the same time drives the wafer 10 to be heated to rotate, entering a closed-loop heating process.

[0045] In this embodiment, different groups of wafer heating elements 1 are arranged corresponding to different areas of the wafer 10 to be heated, so as to heat the corresponding areas of the wafer, and the heating power of each group of wafer heating elements 1 can be controlled individually; accordingly, different groups of wafer temperature sensors 2 are used to measure the wafer temperatures corresponding to different areas.

[0046] Specifically, the wafer 10 to be heated has a plurality of regions centered on its central axis, wherein the innermost region is a circular region, and the remaining regions are annular regions surrounding from the inside to the outside in sequence. Based on the different regions of the wafer 10, in this embodiment, each group of wafer heating elements 1 is respectively arranged in a ring around the central axis of the wafer 10 to be heated above the wafer 10 to be heated (different groups of wafer heating elements have different radii relative to the central axis of the wafer), and multiple groups of wafer heating elements 1 are arranged to correspond one-to-one to different regions of the wafer 10. Correspondingly, each group of wafer temperature sensors 2 is respectively arranged in a ring around the central axis of the wafer 10 to be heated below the wafer 10 to be heated (different groups of wafer temperature sensors have different radii relative to the central axis of the wafer), and multiple groups of wafer temperature sensors 2 are arranged to correspond one-to-one to different regions of the wafer 10.

[0047] In this embodiment, the wafer heating element 1 is preferably implemented by a heating lamp, and the wafer temperature sensor 2 is preferably implemented by a pyrometer. Figure 1-Figure 3 In the example shown, there are 7 groups of heating elements in the device. Accordingly, there are 7 groups of wafer temperature sensors 2 in the device, which can be sequentially recorded as T1, T2, T3, T4, T5, T6 and T7 from the center to the outside.

[0048] In this embodiment, the support ring heating element 5 is disposed above the support ring 4 to heat the support ring 4; the support ring temperature sensor 6 is disposed below the support ring 4 to measure in real time the temperature of the support ring 4. The support ring heating element 5 is also preferably implemented by a heating lamp, and the support ring temperature sensor 6 is also preferably implemented by a pyrometer.

[0049] When the wafer 10 to be heated is transferred to the reaction chamber, it is first placed on the support pins 3 (such as Figure 1 As shown), the heating control device then starts to control the wafer heating element 1 and the support ring heating element 5 to heat the wafer 10 to be heated and the support ring 4 at a preset constant heating power (such as 5%-20% of the rated power). This heating stage can be defined as the initial open-loop heating stage.

[0050] After the initial open-loop heating stage is executed for a predetermined time (such as 5-8s), in order to reduce wafer warpage, the heating control device determines the wafer heating rate of different areas according to the wafer temperatures of different areas measured by each group of wafer temperature sensors 2 (the heating rate reflects the heat absorption capacity), and adjusts the heating power of the corresponding group of wafer heating elements 1 according to the wafer heating rates of different areas, so that the wafer heating rates of different areas are maintained within the predetermined wafer heating rate range (such as 10-15°C / s); the heating control device also adjusts the heating power of the support ring heating element 5 based on the difference between the temperature of the support ring 4 and the temperature of the wafer 10 to be heated, so that the difference between the temperature of the support ring 4 and the temperature of the wafer 10 to be heated is less than a preset temperature difference threshold (such as 30°C) until the temperature of the wafer 10 to be heated reaches a first temperature threshold (such as 200°C).

[0051] It should be understood that the temperature of the wafer 10 to be heated here can be determined based on the wafer temperatures of different areas measured by the aforementioned groups of wafer temperature sensors 2 (for example, the wafer temperature of any area, the average wafer temperature of different areas, or the wafer temperature of the area closest to the edge, etc.), or a separate temperature sensor can be additionally provided to measure the wafer temperature at a specified position as the temperature of the wafer 10 to be heated. This embodiment does not impose any specific restrictions on this.

[0052] When the temperature of the wafer 10 to be heated reaches the aforementioned first temperature threshold, the support pins 3 begin to descend and drive the wafer 10 to be heated to be placed on the support ring 4 (such as Figure 2 As shown), the closed-loop heating stage is entered, and the heating control device starts to perform closed-loop control on the heating power of each group of wafer heating elements 1 based on the wafer temperatures corresponding to different areas, until the temperature of the wafer 10 to be heated reaches the second temperature threshold. It should be understood that any suitable closed-loop control heating strategy can be adopted in this embodiment, and no specific limitation is made to this.

[0053] It can be seen that, on the one hand, this embodiment determines the wafer heating rate of different areas according to the wafer temperatures corresponding to different areas, and adjusts the heating power of the corresponding group of wafer heating elements 1 according to the wafer heating rates of different areas, so that the wafer heating rates of different areas are maintained within the predetermined wafer heating rate range, thereby avoiding warping caused by excessive temperature differences in different areas of the wafer; on the other hand, the heating power of the support ring heating element 5 is adjusted based on the temperature difference between the support ring 4 and the temperature of the wafer 10 to be heated, so that the temperature difference between the support ring 4 and the temperature of the wafer 10 to be heated is less than the preset temperature difference threshold, thereby avoiding warping caused by excessive temperature difference between the wafer 10 and the support ring 4, thereby reducing the frequency of process failures and achieving the purpose of improving process stability and improving production efficiency.

[0054] Example 2

[0055] This embodiment provides a temperature control method for a rapid thermal processing device. Figure 1-Figure 3 As shown, the rapid thermal processing equipment includes: a plurality of groups of wafer heating elements 1 arranged corresponding to different areas of a wafer 10 to be heated, a plurality of groups of wafer temperature sensors 2 for measuring the wafer temperatures corresponding to different areas, a support ring 4 for supporting the wafer 10 to be heated after the temperature of the wafer 10 to be heated reaches a preset first temperature threshold (supported by support pins 3 before the first temperature threshold is reached), a support ring heating element 5 for heating the support ring 4, and a support ring temperature sensor 6 for measuring the temperature of the support ring 4.

[0056] Based on the previous rapid heat treatment equipment, such as Figure 4 As shown, the temperature control method provided in this embodiment specifically includes the following steps:

[0057] S1, when the wafer 10 to be heated is transferred to the reaction chamber and placed on the support pins 3 (such as Figure 1 As shown), the wafer heating element 1 and the support ring heating element 5 are controlled to heat the wafer 10 and the support ring 4 for a predetermined time (such as 5-8s) at a preset constant heating power (such as 5%-20% of the rated power).

[0058] S2, control the wafer heating element 1 and the support ring heating element 5 to continue heating, and during the heating process, determine the wafer heating rate in different areas according to the wafer temperatures corresponding to different areas, and adjust the heating power of the corresponding group of wafer heating elements 1 according to the wafer heating rates in different areas, so that the wafer heating rates in different areas are maintained within a predetermined wafer heating rate range (such as 10-15°C / s, etc.), thereby avoiding warping caused by excessive temperature differences in different areas of the wafer 10.

[0059] S3, adjusting the heating power of the support ring heating element 5 based on the temperature difference between the support ring 4 and the temperature of the wafer 10 to be heated, so that the temperature difference between the support ring 4 and the temperature of the wafer 10 to be heated is less than a preset temperature difference threshold (such as 30°C), thereby avoiding warping caused by excessive temperature difference between the wafer 10 and the support ring 4.

[0060] S4, determining whether the temperature of the wafer 10 to be heated reaches a first temperature threshold (eg, 200° C.), if so, executing step S5, otherwise, returning to step S2.

[0061] S5, the support pins 3 are lowered to drive the wafer 10 to be heated to be placed on the support ring 4 (such as Figure 2As shown), the heating power of each group of wafer heating elements 1 is then closed-loop controlled based on the wafer temperatures corresponding to different regions of the wafer 10 until the temperature of the wafer 10 to be heated reaches the second temperature threshold. It should be understood that the second temperature threshold is greater than the first temperature threshold, and any suitable closed-loop control strategy can be adopted in this embodiment, and no specific limitation should be made to this.

[0062] In addition, before adjusting the heating power of the support ring heating element 5 based on the difference between the temperature of the support ring 4 and the temperature of the wafer 10 to be heated, the present embodiment can also determine the heating rate of the support ring 4 according to the temperature of the support ring 4, and adjust the heating power of the support ring heating element 5 according to the heating rate of the support ring 4, so that the heating rate of the support ring 4 is maintained within a predetermined reasonable support ring heating rate range (such as 10-15°C / s).

[0063] In an operative manner, the process conditions for performing the temperature control method of this embodiment are as follows: a low pressure of 1 to 760 Torr, a process temperature of 180 to 1200° C., a process gas containing oxygen, nitrogen, ammonia, oxygen and nitrogen, or oxygen and hydrogen, and a total gas flow rate of 1 to 60 slm. It should be understood that the process conditions herein are only for example and not for limitation.

[0064] It can be seen that, on the one hand, this embodiment determines the wafer heating rate of different areas according to the wafer temperatures corresponding to different areas, and adjusts the heating power of the corresponding group of wafer heating elements 1 according to the wafer heating rates of different areas, so that the wafer heating rates of different areas are maintained within the predetermined wafer heating rate range, thereby avoiding warping caused by excessive temperature differences in different areas of the wafer 10; on the other hand, the heating power of the support ring heating element 5 is adjusted based on the temperature difference between the support ring 4 and the temperature of the wafer 10 to be heated, so that the temperature difference between the support ring 4 and the temperature of the wafer 10 to be heated is less than the preset temperature difference threshold, thereby avoiding warping caused by excessive temperature difference between the wafer 10 and the support ring 4, thereby reducing the frequency of process failures and achieving the purpose of improving process stability and improving production efficiency.

[0065] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A rapid thermal processing device, characterized in that: include: Multiple groups of wafer heating elements, different groups of wafer heating elements correspond to different areas of the wafer to be heated, and the heating power of each group of wafer heating elements can be controlled separately; A plurality of groups of wafer temperature sensors, wherein different groups of wafer temperature sensors are used to measure the wafer temperatures corresponding to the different areas; A support ring, used for supporting the wafer to be heated after the temperature of the wafer to be heated reaches a preset first temperature threshold; a support ring heating element, for heating the support ring; A support ring temperature sensor, used to measure the temperature of the support ring; The heating control device is used, on the one hand, to determine the wafer heating rates of the different regions according to the wafer temperatures corresponding to the different regions, and to adjust the heating powers of the corresponding groups of the wafer heating elements according to the wafer heating rates of the different regions, so that the wafer heating rates of the different regions are all maintained within a predetermined wafer heating rate range. The heating control device is used, on the other hand, to adjust the heating power of the support ring heating elements based on the difference between the temperature of the support ring and the temperature of the wafer to be heated, so that the difference between the temperature of the support ring and the temperature of the wafer to be heated is less than a preset temperature difference threshold, until the temperature of the wafer to be heated reaches the first temperature threshold; as well as Support pins, before the temperature of the wafer to be heated reaches the first temperature threshold, the wafer to be heated is supported by the support pins; after the temperature of the wafer to be heated reaches the first temperature threshold, the support pins drive the wafer to be heated to be placed on the support ring.

2. The rapid thermal processing equipment according to claim 1, characterized in that: Each group of wafer heating elements is respectively arranged above the wafer to be heated around the central axis of the wafer to be heated; Each group of wafer temperature sensors is respectively arranged below the wafer to be heated around the central axis of the wafer to be heated.

3. The rapid thermal processing equipment according to claim 1, characterized in that: The support ring heating element is arranged above the support ring, and the support ring temperature sensor is arranged below the support ring.

4. The rapid thermal processing equipment according to claim 1, characterized in that: The wafer heating element and the support ring heating element are both heating lamps.

5. The rapid thermal processing equipment according to claim 1, characterized in that: The wafer temperature sensor and the support ring temperature sensor are both pyrometers.

6. The rapid thermal processing equipment according to claim 1, characterized in that: When the wafer to be heated is carried on the support ring, the heating control device is further used to perform closed-loop control on the heating power of each group of the wafer heating elements based on the wafer temperatures corresponding to the different areas.

7. A temperature control method for rapid thermal processing equipment, characterized in that: The rapid thermal processing equipment comprises a plurality of groups of wafer heating elements arranged corresponding to different regions of a wafer to be heated, a plurality of groups of wafer temperature sensors for measuring the wafer temperatures corresponding to the different regions, a support ring for supporting the wafer to be heated after the temperature of the wafer to be heated reaches a preset first temperature threshold, a support ring heating element for heating the support ring, a support ring temperature sensor for measuring the temperature of the support ring, and a support pin; wherein the temperature control method comprises: Control the wafer heating element and the support ring heating element to heat for a predetermined time at a preset heating power; Determining the wafer heating rates of the different regions according to the wafer temperatures corresponding to the different regions, and adjusting the heating powers of the corresponding groups of wafer heating elements according to the wafer heating rates of the different regions, so that the wafer heating rates of the different regions are all maintained within a predetermined wafer heating rate range; adjusting the heating power of the support ring heating element based on the difference between the temperature of the support ring and the temperature of the wafer to be heated, so that the difference between the temperature of the support ring and the temperature of the wafer to be heated is less than a preset temperature difference threshold, until the temperature of the wafer to be heated reaches the first temperature threshold; Wherein, before the temperature of the wafer to be heated reaches the first temperature threshold, the wafer to be heated is supported by the support pins; after the temperature of the wafer to be heated reaches the first temperature threshold, the support pins drive the wafer to be heated to be placed on the support ring.

8. The temperature control method according to claim 7, characterized in that: Before adjusting the heating power of the support ring heating element based on the difference between the temperature of the support ring and the temperature of the wafer to be heated, the temperature control method further includes: The heating rate of the support ring is determined according to the temperature of the support ring, and the heating power of the support ring heating element is adjusted according to the heating rate of the support ring, so that the heating rate of the support ring is maintained within a predetermined range of the heating rate of the support ring.

9. The temperature control method according to claim 7, characterized in that: After the wafer to be heated is supported on the support ring, the temperature control method further includes: Based on the wafer temperatures corresponding to the different areas, the heating power of each group of the wafer heating elements is controlled in a closed loop.

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