Rapid thermal annealing device

Abstract

Disclosed in the present application is a rapid thermal annealing device (100), which is used for processing a wafer (41). The rapid thermal annealing device (100) comprises a housing (10), vertical-cavity surface-emitting lasers (20) and a plurality of control modules, wherein a reaction chamber (31) is defined in the housing (10), and the wafer (41) is located in a reaction chamber (11); two vertical-cavity surface-emitting lasers (20) are provided and are both located in the reaction chamber (11), the two vertical-cavity surface-emitting lasers (20) are arranged on two sides of the wafer (41) in the direction of thickness and are configured to heat the wafer (41), and each of the vertical-cavity surface-emitting lasers (20) comprises a plurality of heating units (21); and the number of the control modules is equal to that of the heating units (21), the control modules correspond to the heating units (21) on a one-to-one basis, and each control module is configured to control the turning-on and turning-off of the corresponding heating unit (21) and the magnitude of power thereof.

Description

A rapid thermal annealing apparatus

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 202411201667.8, filed on August 29, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of semiconductor equipment technology, and in particular to a rapid thermal annealing apparatus. Background Technology

[0004] Compared to furnace tube annealing equipment, rapid thermal annealing equipment has the advantages of lower heat budget, less contamination, and shorter processing time. It is widely used in rapid thermal treatment (RTP), rapid annealing (RTA), rapid thermal oxidation (RTO), rapid thermal nitriding (RTN), ion implantation post-annealing, high-temperature diffusion, metal alloys and other fields, and has become one of the indispensable core equipment in advanced semiconductor manufacturing.

[0005] In related technologies, most rapid thermal annealing (RTP) equipment uses halogen lamps as a radiant heat source, employing a specific wavelength (0.3-0.4µm) to heat the wafer individually. The heating range is 200-1200℃, with a heating rate of 20-250℃ / s. The heating phase is programmable, while the cooling phase is not. The maximum temperature difference within the wafer is ±3℃, and the halogen lamp lifespan is approximately 1000 hours. With the continuous advancement of integrated circuit manufacturing technology, device feature sizes are gradually shrinking, placing more stringent demands on the process. The requirement for intra-wafer temperature consistency is below ±1℃. Clearly, traditional RTP equipment no longer meets this requirement.

[0006] Application content

[0007] This application aims to at least address one of the technical problems existing in the prior art. To this end, one objective of this application is to provide a rapid thermal annealing apparatus that enables higher heating efficiency and faster heating rate of the wafer, eliminates temperature differences on the wafer surface, solves the pattern loading effect on the wafer, and thereby improves the annealing quality of the wafer.

[0008] A rapid thermal annealing apparatus according to a first aspect of this application is used for wafer processing, comprising: a housing defining a reaction chamber within the housing, wherein the wafer is located within the reaction chamber; two vertical-cavity surface-emitting lasers (VCSELs), both located within the reaction chamber, the two VCSELs being disposed on opposite sides of the wafer in the thickness direction, the VCSELs being used to heat the wafer, each VCSEL including multiple heating units; and multiple control modules, the number of control modules being equal to and corresponding one-to-one with the number of heating units, each control module being used to control the on / off state and power level of the corresponding heating unit.

[0009] The rapid thermal annealing apparatus according to an embodiment of this application includes two vertical-cavity surface-emitting lasers (VCSELs). The two VCSELs are respectively disposed on both sides of the wafer in the thickness direction. The VCSELs are used to heat the wafer, and can simultaneously heat both sides of the wafer in the thickness direction, resulting in higher heating efficiency and faster heating rate. The VCSELs are configured as multiple heating units, and the power of each heating unit is independently controlled by a corresponding control module, thereby controlling the temperature of the wafer and making the temperature of the wafer surface uniform, so as to eliminate the temperature difference on the wafer surface, solve the pattern load effect of the wafer, and thus improve the quality of the wafer.

[0010] According to one example of this application, a plurality of heating units are arranged sequentially around the center of the vertical cavity surface-emitting laser; or, a plurality of heating units are arranged in a regional configuration.

[0011] According to one example of this application, each heating unit includes multiple sub-heating elements, which are sequentially abutted against each other and arranged in multiple rows and columns.

[0012] According to one example of this application, the power of the sub-heaters increases sequentially in the direction from the center of the vertical cavity surface-emitting laser to both sides of the vertical cavity surface-emitting laser.

[0013] According to one example of this application, in the direction from the center of the vertical cavity surface-emitting laser to both sides of the vertical cavity surface-emitting laser, the number of sub-heating elements in each column decreases sequentially, and the power of the sub-heating elements in each heating unit is equal.

[0014] According to one example of this application, the rapid thermal annealing apparatus further includes: a temperature equalization hood, the temperature equalization hood being located within the housing.

[0015] According to one example of this application, the temperature vapor chamber is located on the side of the vertical cavity surface-emitting laser closer to the wafer.

[0016] According to one example of this application, the temperature equalization hood abuts against the inner wall of the housing to define a receiving cavity between the temperature equalization hood and the inner wall, the vertical cavity surface emitter is located in the receiving cavity, the receiving cavity is filled with cooling liquid, and the inner wall has an inlet and an outlet communicating with the receiving cavity.

[0017] According to one example of this application, the temperature equalization shroud has a cooling chamber filled with a first cooling gas, and the inner wall of the housing has a first air inlet and a first air outlet communicating with the cooling chamber.

[0018] According to an example of this application, the rapid thermal annealing apparatus further includes a temperature measuring instrument located outside the housing. The temperature uniform cover abuts against the inner wall to define a receiving cavity between the temperature uniform cover and the inner wall. A through hole is formed on the inner wall opposite to the temperature measuring instrument. The receiving cavity has a first signal transmission channel communicating with the through hole. The vertical cavity surface emitter (VCSEL) has a second signal transmission channel communicating with the first signal transmission channel. The temperature measuring instrument is used to detect the temperature of the wafer.

[0019] According to one example of this application, the temperature measuring instrument includes an emitting unit, the temperature equalization cover is a transparent component, and the laser signal emitted by the emitting unit passes through the first signal transmission channel, the second signal transmission channel and the temperature equalization cover to detect the temperature of the wafer.

[0020] According to one example of this application, the reaction chamber is filled with a first protective gas, the housing has a second air inlet and a second air outlet communicating with the reaction chamber, and the inner surface of the housing is provided with a metal coating.

[0021] This application also proposes a control method for controlling the aforementioned rapid thermal annealing apparatus. The control method for the rapid thermal annealing apparatus according to the embodiments of this application is applied to the rapid thermal annealing apparatus according to the above embodiments of this application, and the control method includes:

[0022] S101: The vertical cavity surface-emitting laser heats the wafer at a preset power;

[0023] S102: Obtain the heating time of the wafer;

[0024] S103: After the heating time reaches the preset heating time, the measured temperatures of both sides of the wafer are obtained;

[0025] S104: Obtain the temperature difference between the measured temperature and the preset heating temperature;

[0026] S105: Adjust the power of the corresponding vertical cavity surface-emitting laser according to the temperature difference, so that the temperature of the two sides of the wafer is raised to the preset temperature or lowered to the preset temperature.

[0027] According to one example of this application, each side of the wafer has multiple unit regions, and each of the multiple unit regions corresponds one-to-one with multiple rings of heating units, wherein...

[0028] Obtaining the measured temperatures of both sides of the wafer includes:

[0029] S1031: Obtain the measured temperature of each of the said unit regions;

[0030] Adjusting the power of the vertical cavity surface-emitting laser according to the temperature difference includes:

[0031] S1051: Adjust the power of the heating unit corresponding to each unit region according to the temperature difference of each unit region, so that the temperature of the corresponding unit region is raised to a preset temperature or lowered to a preset temperature.

[0032] According to an example of this application, adjusting the power of the heating unit corresponding to each unit region based on the temperature difference of each unit region includes: multiple rings of heating units arranged sequentially outward from the center of the vertical cavity surface-emitting laser as a first ring of heating units, a second ring of heating units, a third ring of heating units, a fourth ring of heating units, and a fifth ring of heating units. The correspondence between the temperature difference and the power of each ring of heating units corresponding to the unit region is shown in the following table:

[0033] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0034] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.

[0035] Figure 1 is a schematic diagram of a rapid thermal annealing apparatus according to an example of this application;

[0036] Figure 2 is a schematic diagram of an example vertical-cavity surface-emitting laser according to this application;

[0037] Figure 3 is a schematic diagram of a vertical cavity surface-emitting laser according to another example of this application;

[0038] Figure 4 is a schematic diagram of the heating and cooling of a wafer according to an example of this application;

[0039] Figure 5 is a schematic diagram of the process for adjusting wafer temperature according to an example of this application;

[0040] Figure 6 is a schematic diagram of another process for adjusting wafer temperature according to an example of this application.

[0041] Reference numerals: 100, Rapid thermal annealing apparatus; 10, Housing; 11, Reaction chamber; 12, Receiving chamber; 121, First signal transmission channel; 13, Inner wall; 131, First air inlet; 132, First air outlet; 133, Through hole; 134, Liquid inlet; 135, Liquid outlet; 14, Second air inlet; 15, Second air outlet; 20, Vertical cavity surface-emitting laser; 21, Heating unit; 22, Sub-heating element; 30, Temperature equalization hood; 31, Cooling chamber; 32, Second signal transmission channel; 41, Wafer; 42, Thermometer; 43, Support frame; 1, First ring heating unit; 2, Second ring heating unit; 3, Third ring heating unit; 4, Fourth ring heating unit; 5, Fifth ring heating unit. Detailed Implementation

[0042] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0043] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0044] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0045] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0046] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0047] The rapid thermal annealing apparatus 100 according to an embodiment of this application is described below with reference to Figures 1-6.

[0048] According to the embodiments of this application, the rapid thermal annealing apparatus 100 is used for processing wafer 41. The rapid thermal annealing apparatus 100 is used to perform rapid thermal annealing on wafer 41, so that wafer 41 can achieve specific crystal structure changes, impurity activation, defect repair or other heat treatment purposes by rapidly heating wafer 41.

[0049] The rapid thermal annealing apparatus 100 includes a housing 10, a vertical-cavity surface-emitting laser 20, and multiple control modules. A reaction chamber 11 is defined within the housing 10, and a wafer 41 is located within the reaction chamber 11. Two vertical-cavity surface-emitting lasers 20 are provided, and the two vertical-cavity surface-emitting lasers 20 are respectively arranged on both sides of the wafer 41 in the thickness direction. The vertical-cavity surface-emitting lasers 20 are used to heat the wafer 41, and can simultaneously heat both sides of the wafer 41 in the thickness direction, resulting in higher heating efficiency and faster temperature rise rate.

[0050] The vertical-cavity surface-emitting laser 20 includes multiple heating units 21. The vertical-cavity surface-emitting laser 20 has good single-mode performance and temperature stability, and the temperature of each heating unit 21 can be precisely controlled. Each heating unit 21 is an emitting laser.

[0051] In related technologies, most rapid thermal annealing equipment uses halogen lamps as radiant heat sources. A specific wavelength (0.3um-0.4um) of radiant heat source is used to heat the wafer 41 individually. Due to the presence of grooves or other shapes on the surface of the wafer 41, or the different materials of the wafer 41 resulting in different light absorption rates, when the wafer 41 is irradiated with the same power, the surface temperature of different areas of the wafer 41 is different, resulting in uneven temperature within the wafer 41. This phenomenon of temperature deviation within the wafer 41 is called pattern loading effect (PLE).

[0052] The number of control modules is equal to and corresponds one-to-one with the number of heating units 21. Each control module is used to control the on / off state and power level of the corresponding heating unit 21. Each heating unit 21 can heat the wafer 41 at the corresponding position. Since the surface of the wafer 41 has a certain area, if all heating units 21 use the same power to heat the wafer 41, the temperature at the center of the wafer 41 will be higher than the temperature at the edge. By controlling the power of the corresponding heating unit 21 through the control module, the wafer 41 can obtain different heating powers, thereby controlling the temperature of the wafer 41 and making the surface temperature of the wafer 41 uniform, so as to eliminate the temperature difference on the surface of the wafer 41. The temperature difference within the wafer 41 can be controlled below ±1℃. By annealing the wafer 41 from both the front and back directions using vertical cavity surface-emitting lasers 20, the temperature difference between the front and back sides of the wafer 41 is made close to uniform, which can solve the pattern load effect of the wafer 41 caused by annealing in only one direction.

[0053] Understandably, the power level of each control module used to control the corresponding heating unit 21 refers to the adjustment of the power level.

[0054] After each control module controls the corresponding heating unit 21 to turn on, each heating unit 21 is heated to the same temperature to heat the wafer 41. The vertical-cavity surface-emitting laser 20 is configured as multiple heating units 21, and the power of the heating unit 21 at the corresponding position of the wafer 41 is independently controlled by the corresponding control module.

[0055] For example, a vertical cavity surface-emitting laser 20 may include four heating units 21, five heating units 21, or six heating units 21, etc.

[0056] In a specific example, when the vertical-cavity surface-emitting laser 20 heats the wafer 41, the heating rate of the wafer 41 can exceed 300℃ / s, and the heating temperature can reach more than 2000℃. However, in reality, the temperature of the wafer 41 can be between 1000℃ and 1200℃ and held for about 1 to 10 seconds. After that, the wafer 41 is annealed. Referring to Figure 4, the wafer 41 is first heated to about 1300℃ in 4 seconds and held for 4 seconds for annealing, and then slowly cooled down.

[0057] The rapid thermal annealing apparatus 100 according to an embodiment of this application includes two vertical-cavity surface-emitting lasers (VCSELs) 20, which are respectively disposed on both sides of the wafer 41 in the thickness direction. The VCSELs 20 are used to heat the wafer 41, and can simultaneously heat both sides of the wafer 41 in the thickness direction, resulting in higher heating efficiency and faster heating rate. The VCSELs 20 are configured as multiple heating units 21, and the power of each heating unit 21 is independently controlled by a corresponding control module, thereby controlling the temperature of the wafer 41. This ensures that the temperature of the wafer 41 surface is uniform, eliminating the temperature difference on the wafer 41 surface, solving the pattern load effect of the wafer 41, and thus improving the annealing quality of the wafer 41.

[0058] According to an example of this application, referring to Figures 2-3, a plurality of heating units 21 are arranged sequentially around the center of the vertical cavity surface-emitting laser 20, which facilitates the arrangement of the plurality of heating units 21. Alternatively, the plurality of heating units 21 are arranged regionally, with each heating unit 21 occupying a portion of the vertical cavity surface-emitting laser 20, which also facilitates the arrangement of the plurality of heating units 21.

[0059] For example, the vertical cavity surface-emitting laser 20 can be circular, rectangular, polygonal, or other irregular shapes.

[0060] According to an example of this application, referring to Figures 2-3, each heating unit 21 includes multiple sub-heating elements 22. The multiple sub-heating elements 22 are sequentially abutted and arranged in multiple rows and columns. This not only facilitates the arrangement of the sub-heating elements 22, but also avoids gaps between the sub-heating elements 22, which would cause a temperature difference on the surface of the wafer 41.

[0061] Referring to Figures 2 and 3, each number in Figures 2 and 3 represents a sub-heating element 22. The same number indicates that they belong to the same heating unit 21. The number 1 indicates that the heating unit 21 has the lowest power, and the number 5 indicates that the heating unit 21 has the highest power. The power of the heating unit 21 increases sequentially from number 1 to number 5. The dashed lines in the figures represent the vertical projection position of the wafer 41.

[0062] The numbers 1 to 5 represent the first heating unit 1, the second heating unit 2, the third heating unit 3, the fourth heating unit 4, and the fifth heating unit 5, respectively.

[0063] For example, each sub-heating element 22 can also be controlled by a control module. The sub-heating element 22 is small in size, which can further enable precise temperature control of the wafer 41 at the corresponding position of the sub-heating element 22, and can further eliminate the temperature difference on the surface of the wafer 41.

[0064] According to an example of this application, referring to FIG3, in the direction from the center of the vertical-cavity surface-emitting laser 20 to both sides of the vertical-cavity surface-emitting laser 20, the power of the sub-heating elements 22 increases sequentially. Since the surface of the wafer 41 has a certain area, if all heating units 21 use the same power to heat the wafer 41, the temperature at the center of the wafer 41 will be higher than the temperature at the edge. By controlling the power of the heating unit 21 corresponding to the center of the wafer 41 to be relatively low, and the power of the heating unit 21 corresponding to the edge of the wafer 41 to be relatively high, the wafer 41 can obtain different heating powers, thereby controlling the temperature of the wafer 41 to eliminate the temperature difference on the surface of the wafer 41, making the surface temperature of the wafer 41 uniform, and solving the pattern load effect of the wafer 41.

[0065] According to an example of this application, referring to FIG3, in the direction from the center of the vertical cavity surface-emitting laser 20 to both sides of the vertical cavity surface-emitting laser 20, the number of sub-heaters 22 in each row decreases sequentially. The position of the sub-heaters 22 can be arranged according to the size of the wafer 41, and the size of the vertical cavity surface-emitting laser 20 can be reasonably planned.

[0066] According to an example of this application, referring to Figures 2-3, the sub-heating element 22 is a polygon with a side length D, satisfying: 100µm ≤ D ≤ 1000µm. When the sub-heating element 22 heats the wafer 41, the size of the sub-heating element 22 is small enough that the heating area of ​​the sub-heating element 22 on the wafer 41 is divided sufficiently, which can further reduce the temperature difference of the wafer 41. The sub-heating element 22 can be rectangular, quadrilateral, or pentagonal, etc.

[0067] For example, the side length of the sub-heating element 22 can be 100um, 300um, 500um, 600um, 700um or 1000um, etc.

[0068] According to an example of this application, referring to Figures 1-3, the power of the sub-heating elements 22 of each heating unit 21 is equal, so that the temperature of the sub-heating elements 22 heating the wafer 41 is also equal, which can further reduce the temperature difference of the wafer 41.

[0069] According to an example of this application, referring to Figures 1-3, the distance A between the vertical-cavity surface-emitting laser 20 and the wafer 41 satisfies: 50mm ≤ A ≤ 100mm. Within this range, the heating efficiency of the vertical-cavity surface-emitting laser 20 on the wafer 41 is relatively high. For example, the distance between the vertical-cavity surface-emitting laser 20 and the wafer 41 can be 50mm, 60mm, 70mm, 90mm, or 100mm.

[0070] According to an example of this application, referring to FIG1, the rapid thermal annealing apparatus 100 further includes a temperature uniform cover 30, which is located inside the housing 10 and on the side of the vertical cavity surface emission laser 20 near the wafer 41. The laser emitted by the vertical cavity surface emission laser 20 can be uniformly transmitted to the wafer 41 through the temperature uniform cover 30, which can improve the heating efficiency of the wafer 41.

[0071] Two temperature-emitting hoods 30 are provided, located on the side of the corresponding vertical cavity surface-emitting laser 20 near the wafer 41.

[0072] According to an example of this application, referring to FIG1, a temperature homogenizer 30 abuts against the inner wall 13 of the housing 10 to define a receiving cavity 12 between the temperature homogenizer 30 and the inner wall 13. A vertical-cavity surface-emitting laser 20 is located within the receiving cavity 12, which is filled with cooling liquid. The inner wall 13 has an inlet 134 and an outlet 135 communicating with the receiving cavity 12. When the vertical-cavity surface-emitting laser 20 is heated, its temperature is high, which can easily damage its lifespan. When the vertical-cavity surface-emitting laser 20 heats the wafer 41, cooling liquid is introduced into the receiving cavity 12 through the inlet 134 and extracted through the outlet 135. This allows the flowing cooling liquid to cool the vertical-cavity surface-emitting laser 20, keeping it at a lower temperature, such as between 40°C and 70°C, which can improve its lifespan. For example, the cooling liquid can be water.

[0073] According to an example of this application, referring to Figure 1, the temperature distribution shroud 30 has a cooling chamber 31 filled with a first cooling gas. The inner wall 13 has a first inlet 131 and a first outlet 132 communicating with the cooling chamber 31. The first cooling gas can be delivered into the cooling chamber 31 through the first inlet 131 and extracted through the first outlet 132. The flowing first cooling gas can cool the vertical-cavity surface-emitting laser 20, further avoiding the problem of excessively high temperature during heating of the vertical-cavity surface-emitting laser 20. For example, the first cooling gas can be argon, nitrogen, or helium.

[0074] Each temperature distribution hood 30 has a cooling chamber 31 inside.

[0075] According to an example of this application, referring to FIG1, the rapid thermal annealing apparatus 100 further includes a temperature sensor 42 located outside the housing 10. A through-hole 133 is formed on the inner wall 13 opposite to the temperature sensor 42. A first signal transmission channel 121 communicating with the through-hole 133 is located within the receiving cavity 12. A second signal transmission channel 32 communicating with the first signal transmission channel 121 is located within the vertical-cavity surface-emitting laser 20. The temperature sensor 42 includes an emitting unit. The laser signal emitted by the emitting unit passes through the first signal transmission channel 121, the second signal transmission channel 32, and a temperature homogenizing cover 30. The temperature homogenizing cover 30 is transparent, allowing the laser signal to pass through the cover and reach the surface of the wafer 41 for temperature detection. The temperature of the wafer 41 can be detected in real time by the temperature sensor 42, allowing adjustment of the power of the vertical-cavity surface-emitting laser 20 according to the temperature of the wafer 41 for subsequent heating steps.

[0076] The thermometer 42 can be a thermocouple or an optical thermometer, or not limited to these.

[0077] According to an example of this application, the temperature measuring instrument 42 is a laser temperature measuring instrument. The laser temperature measuring instrument can also detect the temperature of the outer surface of the wafer 41 at different locations, and adjust the power of the heating unit 21 of the corresponding vertical cavity surface-emitting laser 20 in real time according to the temperature at different locations, thereby adjusting the temperature of the wafer 41 to improve the temperature uniformity of the wafer 41.

[0078] The laser signal emitted by the thermometer 42 reaches the surface of the wafer 41. The infrared sensor inside the thermometer 42 receives the infrared radiation emitted or reflected by the wafer 41. The infrared radiation is converted into an electrical signal by the sensor and then processed by the electronic circuit to calculate the surface temperature of the wafer 41.

[0079] Two temperature measuring instruments 42 are also provided, which are used to detect the temperature of the two sides of the wafer 41 in the thickness direction, and feed back the detected temperature to the control module in real time. The control module controls and adjusts the power of each heating unit 21 according to the detected temperature in real time, so as to ensure that the temperature of the two sides of the wafer 41 in the thickness direction is more uniform.

[0080] According to an example of this application, referring to FIG1, a support frame 43 for placing a wafer 41 is provided between two vertical cavity surface-emitting lasers 20. The support frame 43 is used to support the wafer 41. A robotic arm can be used to place the wafer 41 onto the support frame 43. After heating is completed, a robotic arm can be used to remove the wafer 41 from the support frame 43.

[0081] According to an example of this application, referring to FIG1, the reaction chamber 11 is filled with a first protective gas, and the housing 10 has a second air inlet 14 and a second air outlet 15 communicating with the reaction chamber 11. When heating the wafer 41, the first protective gas is introduced into the reaction chamber 11 to expel the air in the reaction chamber 11, so as to prevent the wafer 41 from reacting with impurities in the air and damaging the wafer 41. Furthermore, after the wafer 41 is heated, a high-pressure first protective gas can be introduced into the reaction chamber 11. The first protective gas can be introduced into the reaction chamber 11 through the second air inlet 14, and the first protective gas in the reaction chamber 11 can be discharged through the second air outlet 15. The flowing first protective gas can be used to cool the wafer 41, which can improve the cooling rate of the wafer 41.

[0082] For example, the first protective gas can be argon, nitrogen, or oxygen.

[0083] According to an example of this application, referring to Figures 1-3, the inner surface of the housing 10 is provided with a metal coating. When the vertical cavity surface-emitting laser 20 heats the wafer 41, the vertical cavity surface-emitting laser 20 can emit laser light to the wafer 41. When the laser light is emitted onto the metal coating, the metal coating can reflect the laser light well so that the laser light is reflected onto the wafer 41 to heat the wafer 41.

[0084] For example, the material of the metal coating can be gold or silver, as gold and silver have relatively good reflectivity. Understandably, other suitable materials can also be selected for the metal coating.

[0085] The control method of the wafer rapid thermal annealing apparatus 100 according to the second aspect embodiment of this application is applied to the rapid thermal annealing apparatus 100 according to the first aspect embodiment of this application. Referring to FIG5, the control method includes the following steps:

[0086] S101: A vertical-cavity surface-emitting laser heats the wafer at a preset power;

[0087] S102: Obtain the wafer heating time;

[0088] S103: After the heating time reaches the preset heating time, obtain the measured temperature of both sides of the wafer;

[0089] S104: Obtain the temperature difference between the measured temperature and the preset heating temperature;

[0090] S105: Adjust the power of the corresponding vertical cavity surface-emitting laser according to the temperature difference, so that the temperature of both sides of the wafer is raised to the preset temperature or lowered to the preset temperature.

[0091] The preset heating temperature and preset heating time of wafer 41 can be stored in the control module. The preset heating temperature can be any temperature between 1000℃ and 1200℃, specifically 1000℃, 1200℃, 1500℃, 1800℃, or 2000℃. The preset heating temperature of wafer 41 can be determined based on its characteristics. For example, the preset heating time can be 4 seconds, 5 seconds, or other times. It should be noted that the preset heating time and preset heating temperature are related; the preset heating temperature is the target heating temperature at the preset heating time. Understandably, dividing the preset heating temperature and preset heating time yields the preset heating rate, or the preset heating rate can be set directly. Each of the two sides of wafer 41 has a temperature measuring point. The temperature of the two measuring points can be detected by a temperature measuring instrument 42 to obtain the measured temperature of the two sides of wafer 41.

[0092] The control module controls the vertical cavity surface-emitting lasers 20 on both sides of the wafer 41 to heat the wafer at a preset power.

[0093] When the heating time reaches the preset heating time, the actual temperature of both sides of the wafer 41 at the preset heating time is obtained. Temperature measuring instruments 42 are provided on both sides of the wafer 41 in the thickness direction. The temperature measuring instruments 42 can obtain the actual temperature of both sides of the wafer 41 in real time.

[0094] If the preset heating temperature of wafer 41 is equal to the measured temperature of wafer 41, there is no need to adjust the power of vertical-cavity surface-emitting laser 20; if the measured temperature of wafer 41 is greater than the preset heating temperature of wafer 41, the power of vertical-cavity surface-emitting laser 20 is reduced; if the measured temperature of wafer 41 is less than the preset heating temperature of wafer 41, the power of vertical-cavity surface-emitting laser 20 is increased.

[0095] The power of the crystal vertical cavity surface-emitting laser 20 is adjusted in real time according to the difference between the preset heating temperature and the measured temperature, so as to control the heating temperature of the wafer 41 within the preset heating temperature range.

[0096] The control module has pre-stored the temperature difference and the power adjustment relationship of the heating unit 21 of the vertical cavity surface-emitting laser 20. The control module adjusts the power of the heating unit 21 according to the temperature difference between the preset heating temperature and the measured temperature and the power adjustment relationship of the heating unit 21 of the vertical cavity surface-emitting laser 20.

[0097] For example, when the preset heating temperature is 1200℃ and the preset heating time is 4 seconds, after the wafer 41 is heated at a preset power of 100kW for 4 seconds, the measured temperature on both sides of the wafer 41 is 1000℃. By querying the power adjustment relationship, it can be found that when the temperature difference is 200℃, the power of the vertical cavity surface emission laser 20 needs to be increased by 20kW. Therefore, the control module controls the overall power of the vertical cavity surface emission laser 20 to increase by 20kW, which can be evenly distributed to each heating unit 21.

[0098] According to the control method of the rapid thermal annealing apparatus 100 in the embodiments of this application, the power of the crystal vertical cavity surface-emitting laser 20 is adjusted in real time according to the difference between the preset heating temperature and the measured temperature, so as to control the heating temperature of the wafer 41 to accurately reach the preset heating temperature within the preset heating time.

[0099] According to an example of this application, referring to FIG6, each side of the wafer 41 has a plurality of unit regions, and the plurality of unit regions correspond one-to-one with a plurality of heating units 21, wherein S101: the vertical cavity surface emission laser 20 heats the wafer with a preset power;

[0100] S102: Obtain the wafer heating time;

[0101] S1031: After the heating time reaches the preset heating time, obtain the measured temperature of each unit area;

[0102] S104: Obtain the temperature difference between the measured temperature and the preset heating temperature;

[0103] S105: Adjust the power of the heating unit corresponding to each unit area according to the temperature difference of each unit area, so that the temperature of both sides of the wafer is raised to the preset heating temperature or lowered to the preset heating temperature.

[0104] The temperature sensor 42 acquires the measured temperatures of the cell regions on both sides of the wafer 41. It can detect the temperature of the cell regions on both sides of the wafer 41 along its thickness direction. Each side of the wafer 41 has multiple cell regions, and the temperature of at least one location within each cell region can be measured. The measured temperature at that location represents the temperature of that cell region. The temperature sensor 42 can be a multispectral radiation thermometer, capable of simultaneously measuring the temperature at multiple locations.

[0105] The power of the heating unit 21 of the vertical cavity surface emission laser 20, which corresponds to each unit region of the wafer 41, is adjusted according to the preset heating temperature and the measured temperature at multiple locations. The measured temperature at multiple locations of the wafer 41 is obtained. A temperature measuring instrument 42 is provided on both sides of the wafer 41 in the thickness direction. The power of the heating unit 21 of the vertical cavity surface emission laser 20 at the corresponding position of the wafer 41 is adjusted according to the difference between the preset temperature and the measured temperature at multiple locations.

[0106] The control module obtains the difference between the preset heating temperature and the actual measured temperature of each cell area of ​​wafer 41.

[0107] The control module pre-stores the temperature difference and the power adjustment relationship of the heating unit 21 of the vertical cavity surface-emitting laser 20. The control module adjusts the power of the heating unit 21 according to the temperature difference and the power adjustment relationship.

[0108] If the preset heating temperature of wafer 41 is equal to the measured temperature of a certain unit region of wafer 41, there is no need to adjust the power of the corresponding heating unit 21 of the vertical-cavity surface-emitting laser 20. If the measured temperature of a certain unit region of wafer 41 is greater than the preset heating temperature of wafer 41, the power of the heating unit 21 of the vertical-cavity surface-emitting laser 20 in the corresponding unit region of wafer 41 is reduced. If the measured temperature of a certain unit region of wafer 41 is less than the preset heating temperature of wafer 41, the power of the heating unit 21 of the vertical-cavity surface-emitting laser 20 in the corresponding unit region of wafer 41 is increased. The power of the heating unit 21 of the vertical-cavity surface-emitting laser 20 in the corresponding unit region of wafer 41 is adjusted in real time according to the difference between the preset heating temperature and the measured temperature to reduce the temperature difference inside wafer 41 and improve the temperature uniformity of wafer 41.

[0109] According to an example of this application, referring to Figures 2-5, adjusting the power of the heating unit 21 corresponding to each unit region based on the temperature difference includes: multiple heating units 21 are arranged sequentially around the center of the vertical cavity surface-emitting laser 20, forming a first ring of heating unit 1, a second ring of heating unit 2, a third ring of heating unit 3, a fourth ring of heating unit 4, and a fifth ring of heating unit 5. The correspondence between the temperature difference and the power of each ring of heating unit 21 corresponding to the unit region is shown in the table below:

[0110] Referring to Figures 2 and 3, the same numbers represent a heating unit 21.

[0111] Table 1 Power Adjustment Relationship Table

[0112] When the preset heating temperature is 1200℃ and the preset heating time is 4 seconds, after the wafer 41 is heated at a preset power of 100kW for 4 seconds, the measured temperature of the unit area of ​​the wafer 41 is 1000℃, and the temperature difference is -200℃. This unit area corresponds to the second ring of heating unit 21. By referring to the power adjustment relationship in Table 1, it can be seen that the power of the second ring of heating unit 2 needs to be increased by 4.9kW.

[0113] When the preset heating temperature is 1200℃ and the preset heating time is 4 seconds, after the wafer 41 is heated at a preset power of 100kW for 4 seconds, the measured temperature of the unit area of ​​the wafer 41 is 1300℃. When the temperature difference is +100℃, the unit area corresponds to the fourth heating unit 4 of the heating unit 21. By referring to the power adjustment relationship in Table 1, it can be seen that the power of the fourth heating unit 4 needs to be reduced by 5.2kW.

[0114] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A rapid thermal annealing apparatus (100) for processing a wafer (41), wherein, include: A housing (10) defines a reaction chamber (11) within the housing (10), and the wafer (41) is located within the reaction chamber (11); Vertical cavity surface-emitting laser (20), two vertical cavity surface-emitting lasers (20) are provided and both are located in the reaction cavity (11). The two vertical cavity surface-emitting lasers (20) are arranged on both sides of the thickness direction of the wafer (41) and are used to heat the wafer (41). The vertical cavity surface-emitting laser (20) includes multiple heating units (21). Multiple control modules are provided, the number of which is equal to and corresponds one-to-one with the number of heating units (21). Each control module is used to control the opening, closing and power of the corresponding heating unit (21).

2. The rapid thermal annealing apparatus (100) according to claim 1, wherein, The multiple heating units (21) are arranged sequentially around the center of the vertical cavity surface-emitting laser (20); or the multiple heating units (21) are arranged in a regional pattern.

3. The rapid thermal annealing apparatus (100) according to claim 1 or 2, wherein, Each heating unit (21) includes multiple sub-heating elements (22), which are sequentially connected and arranged in multiple rows and columns.

4. The rapid thermal annealing apparatus (100) according to claim 3, wherein, The power of the sub-heater (22) increases sequentially in the direction from the center of the vertical cavity surface-emitting laser (20) to both sides of the vertical cavity surface-emitting laser (20).

5. The rapid thermal annealing apparatus (100) according to claim 3, wherein, In the direction from the center of the vertical cavity surface-emitting laser (20) to both sides of the vertical cavity surface-emitting laser (20), the number of sub-heating elements (22) in each row decreases sequentially, and the power of the sub-heating elements (22) in each heating unit (21) is equal.

6. The rapid thermal annealing apparatus (100) according to claim 1, wherein, Also includes: Temperature equalization hood (30) is located inside the reaction chamber (11).

7. The rapid thermal annealing apparatus (100) according to claim 6, wherein, The temperature distribution cover (30) is located on the side of the vertical cavity surface-emitting laser (20) near the wafer (41).

8. The rapid thermal annealing apparatus (100) according to claim 7, wherein, The temperature equalization shield (30) abuts against the inner wall (13) of the housing (10) to define a receiving cavity (12) between the temperature equalization shield (30) and the inner wall (13). The vertical cavity surface emitter (20) is located in the receiving cavity (12). The receiving cavity (12) is filled with cooling liquid. The inner wall (13) has an inlet (134) and an outlet (135) communicating with the receiving cavity (12).

9. The rapid thermal annealing apparatus (100) according to claim 7, wherein, The temperature equalization cover (30) has a cooling chamber (31) inside, the cooling chamber (31) is filled with a first cooling gas, and the inner wall (13) of the shell (10) has a first air inlet (131) and a first air outlet (132) communicating with the cooling chamber (31).

10. The rapid thermal annealing apparatus (100) according to claim 6, wherein, It also includes: a thermometer (42), the thermometer (42) being located outside the housing (10), the temperature equalization cover (30) abutting against the inner wall (13) of the housing (10), a receiving cavity (12) being provided between the temperature equalization cover (30) and the inner wall (13), a through hole (133) being formed on the inner wall (13) opposite to the thermometer (42), a first signal transmission channel (121) communicating with the through hole (133) being provided in the receiving cavity (12), and a second signal transmission channel (32) communicating with the first signal transmission channel (121) being provided in the vertical cavity surface emitter (20), the thermometer (42) being used to detect the temperature of the wafer (41).

11. The rapid thermal annealing apparatus (100) according to claim 10, wherein, The temperature measuring instrument (42) includes an emitting unit, and the temperature equalization cover (30) is a transparent part. The laser signal emitted by the emitting unit passes through the first signal transmission channel (121), the second signal transmission channel (32) and the temperature equalization cover (30) to detect the temperature of the wafer (41).

12. The rapid thermal annealing apparatus (100) according to claim 1, wherein, The reaction chamber (11) is filled with a first protective gas, and the housing (10) has a second air inlet (14) and a second air outlet (15) communicating with the reaction chamber (11). The inner surface of the housing (10) is provided with a metal coating.

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