Rapid thermal annealing device and control method

Abstract

The invention discloses a rapid thermal annealing device and a control method, the rapid thermal annealing device is used for wafer processing, the rapid thermal annealing device comprises a shell, a vertical cavity surface emitting laser and a plurality of control modules, and a reaction cavity is defined in the shell; the number of the vertical cavity surface emitting lasers is two, the two vertical cavity surface emitting lasers are both located in the reaction cavity, the two vertical cavity surface emitting lasers are arranged on the two sides of the wafer in the thickness direction and used for heating the wafer located in the reaction cavity, and each vertical cavity surface emitting laser comprises a plurality of heating units; the number of the control modules is equal to that of the heating units, and the control modules are in one-to-one correspondence with the heating units; and each control module is used for controlling the opening, closing and power of the corresponding heating unit. The rapid thermal annealing device comprises the two vertical cavity surface emitting lasers, so that the heating efficiency of the wafer is higher, the heating rate is higher, the temperature difference on the surface of the wafer can be eliminated, the pattern load effect of the wafer is solved, and the annealing quality of the wafer is further improved.

Description

[0001] This application is a divisional application. The application number of the original application is 202411201667.8, the filing date of the original application is August 29, 2024, the invention title of the original application is a rapid thermal annealing device, and the entire content of the original application is incorporated herein by reference. Technical Field

[0002] The present invention relates to the technical field of semiconductor equipment, and in particular to a rapid thermal annealing device and a control method. Background Art

[0003] Compared with furnace annealing equipment, rapid thermal annealing equipment has the characteristics of less thermal budget, less contamination, and short processing time. It is widely used in fields such as rapid thermal processing (RTP), rapid thermal annealing (RTA), rapid thermal oxidation (RTO), rapid thermal nitridation (RTN), post-implantation annealing, high-temperature diffusion, and metal alloying, and has become one of the indispensable core equipment for advanced semiconductor manufacturing.

[0004] In related technologies, most rapid thermal annealing equipment uses halogen lamp radiation heat sources. A single wafer is heated by a radiation heat source with a specific wavelength (0.3 - 0.4 um). The heating range is 200 - 1200 °C, the heating rate is 20 - 250 °C / S, the heating stage is programmable, the cooling stage is not programmable, the maximum temperature difference within the wafer is ±3 °C, and the service life of the halogen lamp tube is about 1000 h. With the continuous progress of integrated circuit manufacturing technology, the device feature size has gradually decreased, and more stringent requirements have been put forward for the process. The requirement for temperature uniformity within the wafer is to reach below ±1 °C. Obviously, traditional RTP equipment no longer meets the requirement of temperature uniformity within the wafer. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. For this reason, an object of the present invention is to provide a rapid thermal annealing device, which has higher heating efficiency and faster heating rate for the wafer, can also eliminate the temperature difference on the surface of the wafer, solves the pattern loading effect of the wafer, and thus improves the annealing quality of the wafer.

[0006] A rapid thermal annealing device according to an embodiment of the first aspect of the present invention is used for processing wafers, and includes: a housing, a reaction chamber is defined in the housing, and the wafer is located in the reaction chamber; vertical cavity surface emitting lasers, there are two vertical cavity surface emitting lasers, and both are located in the reaction chamber, the two vertical cavity surface emitting lasers are arranged on both sides in the thickness direction of the wafer, the vertical cavity surface emitting lasers are used to heat the wafer, and the vertical cavity surface emitting lasers include a plurality of heating units; a plurality of control modules, the number of the control modules is equal to and corresponds to the number of the heating units one by one, and each control module is used to control the on, off and power of the corresponding heating unit.

[0007] The rapid thermal annealing device according to an embodiment of the present invention includes two vertical cavity surface emitting lasers, the two vertical cavity surface emitting lasers are respectively arranged on both sides in the thickness direction of the wafer, and the vertical cavity surface emitting lasers are used to heat the wafer, and can heat both sides in the thickness direction of the wafer at the same time, with higher heating efficiency and faster heating rate; the vertical cavity surface emitting lasers are set as a plurality of heating units, and the power of the heating units is independently controlled by the corresponding control modules respectively, and then the temperature of the wafer is controlled to make the temperature on the surface of the wafer consistent, so as to eliminate the temperature difference on the surface of the wafer, solve the pattern loading effect of the wafer, and improve the quality of the wafer.

[0008] According to some embodiments of the present invention, the plurality of heating units are arranged in a ring shape in sequence from the center of the vertical cavity surface emitting laser to the outside; alternatively, the plurality of heating units are arranged in a regional manner.

[0009] According to some embodiments of the present invention, each heating unit includes a plurality of sub-heating elements, the plurality of sub-heating elements are in contact with each other in sequence and are arranged in multiple rows and multiple columns.

[0010] According to some embodiments of the present invention, in the direction from the center of the vertical cavity surface emitting laser to both sides of the vertical cavity surface emitting laser, the power of the sub-heating elements increases in sequence.

[0011] According to some embodiments of the present invention, 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 the sub-heating elements in each column decreases in sequence, and the power of the sub-heating elements of each heating unit is equal.

[0012] According to some embodiments of the present invention, the rapid thermal annealing device further includes: a temperature equalizing cover, the temperature equalizing cover is located in the housing and on the side of the vertical cavity surface emitting laser close to the wafer.

[0013] According to some embodiments of the present invention, the temperature equalizing cover abuts against the side wall of the housing to define a receiving cavity between the temperature equalizing cover and the side wall. The vertical cavity surface emitting laser is located in the receiving cavity, and the receiving cavity is filled with a cooling liquid. The side wall has a liquid inlet and a liquid outlet communicating with the receiving cavity.

[0014] According to some embodiments of the present invention, the temperature equalizing cover has a cooling cavity filled with a first cooling gas. The side wall of the housing has a first air inlet and a first air outlet communicating with the cooling cavity.

[0015] According to some embodiments of the present invention, the rapid thermal annealing device further includes a thermometer located outside the housing. The temperature equalizing cover abuts against the side wall to define a receiving cavity between the temperature equalizing cover and the side wall. A through hole is formed on the side wall opposite to the thermometer. A first signal transmission channel communicating with the through hole is provided in the receiving cavity, and a second signal transmission channel communicating with the first signal transmission channel is provided in the vertical cavity surface emitting laser. The thermometer includes a transmitting unit. The temperature equalizing cover is a transparent member. The laser signal emitted by the transmitting unit passes through the first signal transmission channel, the second signal transmission channel, and the temperature equalizing cover to detect the temperature of the wafer.

[0016] According to some embodiments of the present invention, the reaction cavity is filled with a first protective gas. The housing has a second air inlet and a second air outlet communicating with the reaction cavity. The inner surface of the housing is provided with a metal coating.

[0017] The present invention also proposes a control method for controlling the above-mentioned rapid thermal annealing device. The control method of the rapid thermal annealing device according to the embodiments of the present invention is applied to the rapid thermal annealing device according to the above embodiments of the present invention. The control method includes:

[0018] S101: The vertical cavity surface emitting laser heats the wafer at a preset power.

[0019] S102: Obtain the heating time of the wafer.

[0020] S103: When the heating time reaches the preset heating time, obtain the measured temperatures on both sides of the wafer.

[0021] S104: Obtain the temperature difference between the measured temperature and the preset heating temperature.

[0022] S105: Adjust the power of the corresponding vertical cavity surface emitting laser according to the temperature difference to heat the temperatures on both sides of the wafer to the preset heating temperature or cool them to the preset heating temperature.

[0023] According to some embodiments of the present invention, each side of the wafer has a plurality of unit areas, and the plurality of unit areas respectively correspond to multiple circles of the heating units, where

[0024] Obtaining the measured temperatures of both sides of the wafer includes:

[0025] S1031: Obtain the measured temperature of each of the unit areas;

[0026] Adjusting the power of the corresponding vertical cavity surface emitting laser according to the temperature difference includes:

[0027] S1051: Adjust the power of the heating unit corresponding to the unit area according to the temperature difference of each of the unit areas, so that the temperature of the corresponding unit area rises to a preset temperature rise, or drops to a preset temperature drop.

[0028] According to some embodiments of the present invention, adjusting the power of the heating unit corresponding to the unit area according to the temperature difference of each of the unit areas includes: The multiple circles of heating units are arranged in sequence from the center of the vertical cavity surface emitting laser to the outside as the first circle of heating units, the second circle of heating units, the third circle of heating units, the fourth circle of heating units, and the fifth circle of heating units. The corresponding relationship between the temperature difference and the power of each circle of heating units corresponding to the unit area is as follows in the table:

[0029]

[0030] The additional aspects and advantages of the present invention will be partly given in the following description, partly will become obvious from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0031] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0032] Figure 1 is a schematic diagram of a rapid thermal annealing device according to some embodiments of the present invention;

[0033] Figure 2 is a schematic diagram of a vertical cavity surface emitting laser according to some embodiments of the present invention;

[0034] Figure 3 is a schematic diagram of a vertical cavity surface emitting laser according to some other embodiments of the present invention;

[0035] Figure 4 is a schematic diagram of the temperature rise and fall of a wafer according to some embodiments of the present invention;

[0036] Figure 5It is a schematic flowchart of adjusting the wafer temperature according to some embodiments of the present invention;

[0037] Figure 6 It is another schematic flowchart of adjusting the wafer temperature according to some embodiments of the present invention.

[0038] Reference numerals:

[0039] 100, rapid thermal annealing device;

[0040] 10, housing; 11, reaction chamber; 12, accommodation chamber; 121, first signal transmission channel; 13, side 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;

[0041] 20, vertical cavity surface emitting laser; 21, heating unit; 22, sub-heating element;

[0042] 30, temperature equalizing cover; 31, cooling chamber; 32, second signal transmission channel;

[0043] 41, wafer; 42, thermometer; 43, support frame;

[0044] 1, first circle heating unit; 2, second circle heating unit; 3, third circle heating unit; 4, fourth circle heating unit; 5, fifth circle heating unit. Detailed implementation manners

[0045] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0046] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0047] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] Reference will be made below to Figures 1-6 describe a rapid thermal annealing apparatus 100 according to an embodiment of the present invention.

[0049] The rapid thermal annealing apparatus 100 according to an embodiment of the present invention is used for the processing of a wafer 41. The rapid thermal annealing apparatus 100 is used to perform rapid thermal annealing on the wafer 41. By rapidly heating the wafer 41, specific crystal structure changes, impurity activation, defect repair, or other heat treatment purposes can be achieved for the wafer 41.

[0050] The rapid thermal annealing apparatus 100 includes a housing 10, vertical cavity surface emitting lasers 20, and a plurality of control modules. A reaction chamber 11 is defined inside the housing 10. The wafer 41 is located inside the reaction chamber 11. The vertical cavity surface emitting lasers 20 are located inside the reaction chamber 11. There are two vertical cavity surface emitting lasers 20. The two vertical cavity surface emitting lasers 20 are respectively arranged on both sides in the thickness direction of the wafer 41. The vertical cavity surface emitting lasers 20 are used to heat the wafer 41, and can heat both sides in the thickness direction of the wafer 41 simultaneously, with higher heating efficiency and faster heating rate.

[0051] The vertical cavity surface emitting laser 20 includes a plurality of 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 accurately controlled. The heating unit 21 is a laser.

[0052] In the related art, most rapid thermal annealing devices use halogen lamp radiation heat sources, and a single wafer 41 is heated by a radiation heat source with a specific wavelength (0.3 μm - 0.4 μm). 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 of the wafer 41, when the wafer 41 is irradiated with the same power, the surface temperatures of different regions of the wafer 41 are different, resulting in non-uniform temperature inside the wafer 41. This phenomenon of temperature deviation inside the wafer 41 is called the pattern loading effect (PLE).

[0053] The number of control modules is equal to and in one-to-one correspondence with the number of heating units 21, and each control module is used to control the on, off, and power 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 the heating units 21 heat the wafer 41 with the same power, the temperature at the center position of the wafer 41 will be higher than that at the edge position; by controlling the power of the corresponding heating unit 21 through the control module, different heating powers can be obtained for the wafer 41, thereby controlling the temperature of the wafer 41 to make the temperature on the surface 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°C. By annealing the wafer 41 from both the front and back directions using the vertical cavity surface emitting laser 20, the temperature difference between the front and back sides of the wafer 41 can be made nearly the same, which can solve the pattern loading effect of the wafer 41 caused by annealing in only one direction.

[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 set 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, the 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°C / S, and the heating temperature reaches above 2000°C. However, in actual situations, the temperature of the wafer 41 can be between 1000°C and 1200°C and maintained for about 1 second to 10 seconds, and then the wafer 41 is annealed. Please refer to Figure 4 The wafer 41 is first heated to about 1300°C within 4 seconds, maintained for 4 seconds for annealing, and then slowly cooled.

[0057] According to the rapid thermal annealing device 100 of the embodiments of the present invention, it includes two vertical cavity surface emitting lasers 20. 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 heat both sides of the wafer 41 in the thickness direction simultaneously, with higher heating efficiency and faster heating rate. The vertical cavity surface emitting lasers 20 are set as multiple heating units 21, and the power of the heating units 21 is independently controlled by the corresponding control modules respectively, so as to control the temperature of the wafer 41, make the temperature on the surface of the wafer 41 consistent, eliminate the temperature difference on the surface of the wafer 41, solve the pattern loading effect of the wafer 41, and further improve the annealing quality of the wafer 41.

[0058] According to some embodiments of the present invention, referring to Figures 2-3 , the multiple heating units 21 are arranged in a circular arrangement in sequence from the center of the vertical cavity surface emitting laser 20 outwards. The multiple heating units 21 are arranged in a circular pattern, which can facilitate the arrangement of the multiple heating units 21. Alternatively, the multiple heating units 21 are arranged in a regional pattern, and each heating unit 21 occupies a part of the position of the vertical cavity surface emitting laser 20, which can facilitate the arrangement of the multiple 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 some embodiments of the present invention, referring to Figures 2-3 , each heating unit 21 includes multiple sub-heating elements 22. The multiple sub-heating elements 22 are abutted in sequence and arranged in multiple rows and columns, which can not only facilitate the arrangement of the sub-heating elements 22, but also avoid gaps in the sub-heating elements 22, resulting in a temperature difference on the surface of the wafer 41.

[0061] Referring to the attached Figures 2-3 shown, Figures 2-3 One number in it represents a sub-heating element 22, and the same numbers represent belonging to the same heating unit 21. The number 1 represents the lowest power of the heating unit 21, the number 5 represents the highest power of the heating unit 21, and from the number 1 to the number 5 represents the power of the heating unit 21 increasing in sequence. The dotted line in the figure is the position of the vertical projection of the wafer 41.

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

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

[0064] According to some embodiments of the present invention, with reference to Figure 3 , 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 in sequence. Since the surface of the wafer 41 has a certain area, if all the heating units 21 heat the wafer 41 with the same power, the temperature at the center position of the wafer 41 will be higher than that at the edge position. By controlling the module to control the power of the heating unit 21 corresponding to the center position of the wafer 41 to be relatively low, and controlling the power of the heating unit 21 corresponding to the edge position 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 temperature on the surface of the wafer 41 consistent, and the pattern loading effect of the wafer 41 can be solved.

[0065] According to some embodiments of the present invention, with reference to Figure 3 , 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 column decreases in sequence. The position of the sub-heating elements 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 some embodiments of the present invention, with reference to Figures 2-3 , the sub-heating element 22 is a polygon, and the side length of the sub-heating element 22 is D, satisfying: 100um ≤ D ≤ 1000um. When the sub-heating element 22 heats the wafer 41, the size of the sub-heating element 22 is small enough so that the position where the sub-heating element 22 heats the wafer 41 can be divided small enough, and the temperature difference of the wafer 41 can be further reduced. The sub-heating element 22 can be a rectangle, a quadrilateral, a pentagon, 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 some embodiments of the present invention, with reference to Figures 1-3 , the power of the sub-heating elements 22 of each heating unit 21 is equal, so that the temperature at the position where the sub-heating elements 22 heat the wafer 41 is also equal, and the temperature difference of the wafer 41 can be further reduced.

[0069] According to some embodiments of the present invention, with reference to Figures 1-3 , the distance between the vertical cavity surface emitting laser 20 and the wafer 41 is A, satisfying: 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 some embodiments of the present invention, with reference to Figure 1 , the rapid thermal annealing apparatus 100 further includes a temperature equalizing cover 30. The temperature equalizing cover 30 is located inside the housing 10 and on the side of the vertical cavity surface emitting laser 20 close to the wafer 41. The laser emitted by the vertical cavity surface emitting laser 20 can be uniformly transmitted to the wafer 41 through the temperature equalizing cover 30, which can improve the heating efficiency of the wafer 41.

[0071] There are two temperature equalizing covers 30, which are respectively located on the side of the corresponding vertical cavity surface emitting laser 20 close to the wafer 41.

[0072] According to some embodiments of the present invention, with reference to Figure 1 , the temperature equalizing cover 30 abuts against the side wall 13 of the housing 10 to define a receiving cavity 12 between the temperature equalizing cover 30 and the side wall 13. The vertical cavity surface emitting laser 20 is located inside the receiving cavity 12, and the receiving cavity 12 is filled with a cooling liquid. The side wall 13 has a liquid inlet 134 and a liquid outlet 135 communicating with the receiving cavity 12. When the vertical cavity surface emitting laser 20 is heating, the temperature of the vertical cavity surface emitting laser 20 is relatively high, which is likely to damage the lifespan of the vertical cavity surface emitting laser 20. When the vertical cavity surface emitting laser 20 heats the wafer 41, cooling liquid is introduced into the receiving cavity 12 through the liquid inlet 134 and the cooling liquid is pumped out through the liquid outlet 135, so that the flowing cooling liquid cools the vertical cavity surface emitting laser 20, keeping the vertical cavity surface emitting laser 20 at a relatively low temperature, such as keeping the vertical cavity surface emitting laser 20 between 40°C and 70°C, which can improve the service life of the vertical cavity surface emitting laser 20. For example, the cooling liquid can be water.

[0073] According to some embodiments of the present invention, with reference to Figure 1 , the temperature equalizing cover 30 has a cooling cavity 31 inside. The cooling cavity 31 is filled with a first cooling gas. The side wall 13 has a first gas inlet 131 and a first gas outlet 132 communicating with the cooling cavity 31. The first cooling gas can be transported into the cooling cavity 31 through the first gas inlet 131 and the first cooling gas is pumped out through the first gas outlet 132. The flowing first cooling gas can cool the vertical cavity surface emitting laser 20, which can further avoid the problem of the temperature of the vertical cavity surface emitting laser 20 being too high when heating. For example, the first cooling gas can be argon, nitrogen or helium, etc.

[0074] Each temperature equalizing cover 30 has a cooling cavity 31 inside.

[0075] According to some embodiments of the present invention, with reference to Figure 1, the rapid thermal annealing apparatus 100 further includes a temperature measuring instrument 42. The temperature measuring instrument 42 is located outside the housing 10. A through hole 133 is formed on the side wall 13 and is disposed opposite to the temperature measuring instrument 42. A first signal transmission channel 121 communicating with the through hole 133 is provided in the accommodation cavity 12. A second signal transmission channel 32 communicating with the first signal transmission channel 121 is provided in the vertical cavity surface emitting laser 20. The temperature measuring instrument 42 includes a transmitting unit. The laser signal emitted by the transmitting unit passes through the first signal transmission channel 121, the second signal transmission channel 32, and the temperature equalizing cover 30. The temperature equalizing cover 30 is a transparent member, so that the laser signal can pass through the temperature equalizing cover 30 to reach the surface of the wafer 41 for detecting the temperature of the wafer 41. The temperature of the wafer 41 can be detected in real time by the temperature measuring instrument 42, so as to adjust the power of the vertical cavity surface emitting laser 20 according to the temperature of the wafer 41 for the subsequent step of heating the wafer 41.

[0076] The temperature measuring instrument 42 can be a thermocouple, an optical temperature measuring instrument, etc., which is not limited thereto.

[0077] According to some embodiments of the present invention, the temperature measuring instrument 42 is a laser temperature measuring instrument. The laser temperature measuring instrument can also detect the temperatures of the outer surfaces at different positions of the wafer 41, and adjust the power of the heating unit 21 of the corresponding vertical cavity surface emitting laser 20 in real time according to the temperatures at different positions, thereby adjusting the temperature of the wafer 41 to improve the temperature uniformity of the wafer 41.

[0078] The laser signal emitted by the temperature measuring instrument 42 reaches the surface of the wafer 41. The infrared sensor inside the temperature measuring instrument 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 an electronic circuit to calculate the surface temperature of the wafer 41.

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

[0080] According to some embodiments of the present invention, referring to Figure 1 , a support frame 43 for placing the wafer 41 is provided between the two vertical cavity surface emitting lasers 20. The support frame 43 is used to support the wafer 41. The wafer 41 can be placed on the support frame 43 by a manipulator. After the heating is completed, the wafer 41 can be taken off the support frame 43 by a manipulator.

[0081] According to some embodiments of the present invention, referring to Figure 1, the reaction chamber 11 is filled with a first protective gas. The housing 10 has a second inlet 14 and a second outlet 15 that communicate with the reaction chamber 11. When heating the wafer 41, filling the reaction chamber 11 with the first protective gas can discharge the air in the reaction chamber 11, preventing the wafer 41 from reacting with impurities in the air and causing damage to the wafer 41. Moreover, after the heating of the wafer 41 is completed, a high-pressure first protective gas can be introduced into the reaction chamber 11. The first protective gas can be filled into the reaction chamber 11 through the second inlet 14, and the first protective gas in the reaction chamber 11 can be discharged through the second outlet 15. The flowing first protective gas can be used to cool the wafer 41, which can increase the cooling rate of the wafer 41.

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

[0083] According to some embodiments of the present invention, referring to Figures 1-3 , a metal coating is provided on the inner surface of the housing 10. When the vertical cavity surface emitting laser 20 heats the wafer 41, the vertical cavity surface emitting laser 20 can emit laser light towards the wafer 41. When the laser light hits the metal coating, the metal coating can reflect the laser light well, so as to reflect the laser light onto the wafer 41 and heat the wafer 41.

[0084] For example, the material of the metal coating can be gold or silver. Gold and silver materials have relatively excellent reflectivity. It can be understood that other suitable materials can also be selected for the metal coating.

[0085] A control method for the wafer rapid thermal annealing device 100 according to the second aspect embodiments of the present invention is applied to the rapid thermal annealing device 100 according to the first aspect embodiments of the present invention. Please refer to Figure 5 , the control method includes the following steps:

[0086] S101: The vertical cavity surface emitting laser raises the temperature of the wafer at a preset power;

[0087] S102: Obtain the temperature rising time of the wafer;

[0088] S103: When the temperature rising time reaches the preset temperature rising time, obtain the measured temperatures on both sides of the wafer;

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

[0090] S105: Adjust the power of the corresponding vertical cavity surface emitting laser according to the temperature difference, so that the temperatures on both sides of the wafer rise to the preset temperature rising temperature, or drop to the preset temperature rising temperature.

[0091] Among them, the preset heating temperature and preset heating time of the wafer 41 can be pre-stored in the control module. The preset heating temperature can be any temperature between 1000°C and 1200°C, such as 1000°C, 1200°C, 1500°C, 1800°C or 2000°C. The preset heating temperature of the wafer 41 can be determined according to the characteristics of the wafer 41. For example, the preset heating time can be 4 seconds, 5 seconds or other time. It should be noted that the preset heating time is related to the preset heating temperature, and the preset heating temperature is the target heating temperature under the preset heating time. It can be understood that after obtaining the preset heating temperature and preset heating time and dividing them, the preset heating rate can be obtained, or the preset heating rate can also be directly set. One temperature measurement point is provided on each of the two side surfaces of the wafer 41, and the temperature of the two temperature measurement points can be detected by the thermometer 42 to obtain the measured temperatures of the two side surfaces of the 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, obtain the measured temperatures of the two side surfaces of the wafer 41 at the preset heating time. Temperature measuring instruments 42 are provided on both side surfaces in the thickness direction of the wafer 41, and the temperature measuring instruments 42 can obtain the measured temperatures of the two side surfaces of the wafer 41 in real time.

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

[0095] According to the difference between the preset heating temperature and the measured temperature, adjust the power of the vertical cavity surface emitting laser 20 in real time to control the heating temperature of the wafer 41 within the range of the preset heating temperature.

[0096] The control module pre-stores the relationship between the temperature difference and the power adjustment 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°C and the preset heating time is 4 seconds, after the wafer 41 is heated at a preset power of 100 kw for 4 seconds, the measured temperatures on both sides of the wafer 41 are both 1000°C. Then, by querying the power adjustment relationship, it can be known that when the temperature difference is 200°C, the power of the vertical cavity surface emitting laser 20 needs to be increased by 20 kw. Therefore, the control module controls the overall power of the vertical cavity surface emitting laser 20 to increase by 20 kw. Specifically, the power can be evenly distributed to each heating unit 21.

[0098] According to the control method of the rapid thermal annealing device 100 according to the embodiment of the present invention, the power of the 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 some embodiments of the present invention, referring to Figure 6 , each side of the wafer 41 has a plurality of unit areas, and the plurality of unit areas respectively correspond to the plurality of heating units 21 one by one. Among them, S101: The vertical cavity surface emitting laser 20 heats the wafer at a preset power;

[0100] S102: Obtain the heating time of the wafer;

[0101] S1031: When 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 the unit area according to the temperature difference of each unit area, so that the temperatures on both sides of the wafer rise to the preset heating temperature or drop to the preset heating temperature.

[0104] Obtain the measured temperatures of the unit areas on both sides of the wafer 41. The thermometer 42 can detect the temperatures of the unit areas on both sides in the thickness direction of the wafer 41. Each side of the wafer 41 has a plurality of unit areas, and at least one position temperature can be detected for each unit area, and the measured temperature at this position represents the temperature of the unit area. The thermometer 42 can be a multi-spectral radiation thermometer, which can measure the temperatures of multiple positions at the same time.

[0105] Adjust the power of the heating units 21 corresponding to the respective unit areas of the wafer 41 according to the preset temperature increase and the measured temperatures at multiple positions, obtain the measured temperatures at multiple positions of the wafer 41, temperature measuring instruments 42 are provided on both sides of the wafer 41 in the thickness direction, and adjust the power of the heating units 21 of the vertical cavity surface emitting lasers 20 at the corresponding positions of the wafer 41 according to the difference between the preset temperature and the measured temperatures at multiple positions.

[0106] The control module obtains the difference between the preset temperature increase and the measured temperature of each unit area of the wafer 41.

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

[0108] If the preset temperature increase of the wafer 41 is equal to the measured temperature of a certain unit area of the 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 area of the wafer 41 is greater than the preset temperature increase of the wafer 41, reduce the power of the heating unit 21 of the vertical cavity surface emitting laser 20 corresponding to the unit area of the wafer 41; if the measured temperature of a certain unit area of the wafer 41 is less than the preset temperature increase of the wafer 41, increase the power of the heating unit 21 of the vertical cavity surface emitting laser 20 corresponding to the unit area of the wafer 41. Adjust the power of the heating units 21 of the vertical cavity surface emitting lasers 20 corresponding to the unit areas of the wafer 41 in real time according to the difference between the preset temperature increase and the measured temperature, so as to reduce the temperature difference inside the wafer 41 and improve the temperature uniformity of the wafer 41.

[0109] According to some embodiments of the present invention, referring to 2- Figure 5 , adjusting the power of the heating units 21 corresponding to the unit areas according to the temperature difference of each unit area includes: The multi-turn heating units 21 are arranged in sequence from the center of the vertical cavity surface emitting laser 20 to the outside as the first-turn heating unit 1, the second-turn heating unit 2, the third-turn heating unit 3, the fourth-turn heating unit 4, and the fifth-turn heating unit 5. The corresponding relationship between the temperature difference and the power of each turn of the heating units 21 corresponding to the unit area is as follows in the table:

[0110] Referring to the appendix Figure 2 and Figure 3 , the same numbers represent one heating unit 21.

[0111] Table 1 Power adjustment relationship table

[0112]

[0113] When the preset heating temperature is 1200 °C and the preset heating time is 4 seconds, after the wafer 41 is heated at a preset power of 100 kw for 4 seconds, the measured temperature of the unit area of the wafer 41 is 1000 °C and the temperature difference is -200 °C. For the second loop heating unit 2 of the heating unit 21 corresponding to this unit area, by referring to the power adjustment relationship in Table 1, it can be known that the power of the second loop heating unit 2 needs to be increased by 4.9 kw.

[0114] When the preset heating temperature is 1200 °C and the preset heating time is 4 seconds, after the wafer 41 is heated at a preset power of 100 kw for 4 seconds, the measured temperature of the unit area of the wafer 41 is 1300 °C and the temperature difference is +100 °C. For the fourth loop heating unit 4 of the heating unit 21 corresponding to this unit area, by referring to the power adjustment relationship in Table 1, it can be known that the power of the fourth loop heating unit 4 needs to be reduced by 5.2 kw.

[0115] In the description of this specification, the descriptions with reference to terms such as "some embodiments", "optionally", "further", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0116] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A rapid thermal annealing device for wafer processing, characterized in that: include: a housing, wherein a reaction chamber is defined in the housing; A vertical cavity surface emitting laser, wherein two vertical cavity surface emitting lasers are provided and both are located in the reaction chamber, the two vertical cavity surface emitting lasers are arranged on both sides of the wafer in the thickness direction and are used to heat the wafer located in the reaction chamber, and the vertical cavity surface emitting lasers include a plurality of heating units; A plurality of control modules, the number of the control modules is equal to the number of the heating units and corresponds one to one, and each of the control modules is used to control the opening, closing and power size of the corresponding heating unit.

2. The rapid thermal annealing device according to claim 1, characterized in that: The plurality of heating units are sequentially arranged around the center of the vertical cavity surface emitting laser outward; or, the plurality of heating units are arranged in a regional manner.

3. The rapid thermal annealing device according to claim 2, characterized in that: Each of the heating units includes a plurality of sub-heating elements, and the plurality of sub-heating elements are abutted in sequence and arranged in multiple rows and columns.

4. The rapid thermal annealing device according to claim 3, characterized in that: In a direction from the center of the vertical cavity surface emitting laser to two sides of the vertical cavity surface emitting laser, the power of the sub-heating element increases sequentially.

5. The rapid thermal annealing device according to claim 3, characterized in that: In the direction from the center of the VCSEL to the two sides of the VCSEL, the number of the sub-heating elements in each column decreases successively, and the power of the sub-heating elements of each heating unit is equal.

6. The rapid thermal annealing device according to claim 1, characterized in that: Also includes: A temperature-averaging cover is located in the shell and on a side of the vertical cavity surface emitting laser close to the wafer.

7. The rapid thermal annealing device according to claim 6, characterized in that: The temperature-average cover abuts against the side wall of the shell to define a containing cavity between the temperature-average cover and the side wall, the vertical cavity surface emitting laser is located in the containing cavity, the containing cavity is filled with cooling liquid, and the side wall has a liquid inlet and a liquid outlet connected to the containing cavity.

8. The rapid thermal annealing device according to claim 6, characterized in that: The temperature-averaging cover has a cooling cavity therein, the cooling cavity is filled with a first cooling gas, and the side wall of the shell has a first air inlet and a first air outlet communicated with the cooling cavity.

9. The rapid thermal annealing device according to claim 8, characterized in that: The invention also includes a thermometer, which is located outside the shell, and the temperature-average cover is abutted against the side wall to define a accommodating chamber between the temperature-average cover and the side wall. A through hole arranged opposite to the thermometer is formed on the side wall, and a first signal transmission channel connected to the through hole is provided in the accommodating chamber, and a second signal transmission channel connected to the first signal transmission channel is provided in the vertical cavity surface emitting laser. The thermometer includes a transmitting unit, and the temperature-average cover is a transparent part. The laser signal emitted by the transmitting unit passes through the first signal transmission channel, the second signal transmission channel and the temperature-average cover to detect the temperature of the wafer.

10. The rapid thermal annealing device according to claim 1, characterized in that: The reaction chamber is filled with a first protective gas, the shell has a second gas inlet and a second gas outlet communicated with the reaction chamber, and the inner surface of the shell is provided with a metal coating.

11. A control method for a rapid thermal annealing device, characterized in that: The control method comprises the following steps: S101: The vertical cavity surface emitting laser heats the wafer at a preset power; S102: Obtaining the heating time of the wafer; S103: When the heating time reaches the preset heating time, the measured temperatures of the two side surfaces of the wafer are obtained; S104: Obtaining the temperature difference between the measured temperature and the preset heating temperature; S105: adjusting the power of the corresponding vertical cavity surface emitting laser according to the temperature difference, so that the temperature of the two side surfaces of the wafer is increased to a preset heating temperature, or decreased to a preset heating temperature.

12. The control method of the rapid thermal annealing device according to claim 11, characterized in that: The step of obtaining the measured temperatures of the two side surfaces of the wafer in S102 includes obtaining the measured temperature of each of the unit areas.

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