A rapid thermal annealing device

Abstract

The present invention discloses a rapid thermal annealing device for processing wafers. The rapid thermal annealing device includes a shell, a vertical cavity surface emitting laser and a plurality of control modules. A reaction chamber is defined in the shell, and the wafer is located in the reaction chamber. 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 thickness direction of the wafer and are used to heat the wafer. The vertical cavity surface emitting laser includes a plurality of heating units. The number of control modules is equal to the number of heating units and corresponds one to one. Each control module is used to control the opening, closing and power size of the corresponding heating unit. According to the rapid thermal annealing device of the present invention, including two vertical cavity surface emitting lasers, the heating efficiency of the wafer is higher, the heating rate is faster, and 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 improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor equipment, and in particular to a rapid thermal annealing device. Background Art

[0002] 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 rapid thermal processing (RTP), rapid annealing (RTA), rapid thermal oxidation (RTO), rapid thermal nitridation (RTN), post-ion implantation annealing, high temperature diffusion, metal alloys and other fields, and has become one of the indispensable core equipment in advanced semiconductor manufacturing.

[0003] In the related technology, most of the rapid thermal annealing equipment uses halogen lamp radiation heat source, and uses a specific wavelength (0.3-0.4um) radiation heat source to heat the wafer in a single piece, with a heating range of 200-1200℃, a heating rate of 20-250℃ / S, programmable control during the heating stage, and non-programmable control during the cooling stage. The maximum temperature difference within the chip is ±3℃, and the service life of the halogen lamp is about 1000h. With the continuous advancement of integrated circuit manufacturing process technology, the device feature size has gradually decreased, and more stringent requirements have been put forward for the process. The temperature consistency within the chip is required to be below ±1℃. Obviously, traditional RTP equipment can no longer meet the requirements of temperature consistency within the chip. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a rapid thermal annealing device, which makes the heating efficiency of the wafer higher, the heating rate faster, and can also eliminate the temperature difference on the surface of the wafer, solve the pattern load effect of the wafer, and thus improve the annealing quality of the wafer.

[0005] According to the first aspect of the present invention, a rapid thermal annealing device is used for processing wafers, comprising: a shell, a reaction chamber is defined in the shell, and the wafer is located in the reaction chamber; a vertical cavity surface emitting laser, 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 thickness direction of the wafer, the vertical cavity surface emitting laser is used to heat the wafer, and the vertical cavity surface emitting laser includes 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.

[0006] According to an embodiment of the present invention, a rapid thermal annealing device comprises two vertical cavity surface emitting lasers, which are respectively arranged on both sides of a wafer in a thickness direction. The vertical cavity surface emitting lasers are used to heat the wafer, and can heat both sides of the wafer in a thickness direction at the same time, so that the heating efficiency is higher and the heating rate is faster. The vertical cavity surface emitting lasers are arranged as a plurality of heating units, and the power of the heating units is independently controlled by corresponding control modules, thereby controlling the temperature of the wafer, so that the temperature of the wafer surface is consistent, thereby eliminating the temperature difference on the wafer surface, solving the pattern load effect of the wafer, and thereby improving the quality of the wafer.

[0007] According to some embodiments of the present invention, 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.

[0008] According to some embodiments of the present invention, each of the heating units includes a plurality of sub-heating elements, and the plurality of sub-heating elements are abutted against each other in sequence and arranged in multiple rows and columns.

[0009] According to some embodiments of the present invention, the power of the sub-heating element increases sequentially in a direction from the center of the vertical cavity surface emitting laser to both sides of the vertical cavity surface emitting laser.

[0010] According to some embodiments of the present invention, in the direction from the center of the VCSEL to both 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.

[0011] According to some embodiments of the present invention, the rapid thermal annealing device further includes: a temperature-homogenizing hood, which is located in the housing and on a side of the vertical cavity surface emitting laser close to the wafer.

[0012] According to some embodiments of the present invention, the temperature-average cover abuts against the inner wall of the shell to define a accommodating cavity between the temperature-average cover and the inner wall, the vertical cavity surface emitting laser is located in the accommodating cavity, the accommodating cavity is filled with cooling liquid, and the inner wall has a liquid inlet and a liquid outlet connected to the accommodating cavity.

[0013] According to some embodiments of the present invention, the temperature-averaging cover has a cooling cavity therein, the cooling cavity is filled with a first cooling gas, and the inner wall of the shell has a first air inlet and a first air outlet connected to the cooling cavity.

[0014] According to some embodiments of the present invention, the rapid thermal annealing device also includes a thermometer, which is located outside the shell, and the temperature-average hood abuts against the inner wall to define a accommodating chamber between the temperature-average hood and the inner wall, and a through hole arranged opposite to the thermometer is formed on the inner 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, and the thermometer includes a transmitting unit, and the temperature-average hood is a transparent part, and a laser signal emitted by the transmitting unit passes through the first signal transmission channel, the second signal transmission channel and the temperature-average hood to detect the temperature of the wafer.

[0015] According to some embodiments of the present invention, the reaction chamber is filled with a first protective gas, the shell has a second gas inlet and a second gas outlet connected to the reaction chamber, and the inner surface of the shell is provided with a metal coating.

[0016] The present invention also proposes a control method for controlling the above-mentioned rapid thermal annealing device. The control method for the rapid thermal annealing device according to an embodiment of the present invention is applied to the rapid thermal annealing device according to the above-mentioned embodiment of the present invention, and the control method includes:

[0017] S101: The vertical cavity surface emitting laser heats the wafer at a preset power;

[0018] S102: Obtaining the heating time of the wafer;

[0019] S103: when the heating time reaches a preset heating time, obtaining the measured temperatures of the two side surfaces of the wafer;

[0020] S104: Obtaining the temperature difference between the measured temperature and the preset heating temperature;

[0021] 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 the preset heating temperature, or decreased to the preset heating temperature.

[0022] 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 correspond one-to-one to the plurality of circles of the heating units, respectively, wherein:

[0023] Obtaining the measured temperatures of the two sides of the wafer includes:

[0024] S1031: Obtaining the measured temperature of each unit area;

[0025] Adjusting the power of the corresponding vertical cavity surface emitting laser according to the temperature difference comprises:

[0026] S1051: adjusting 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 the corresponding unit area is increased to a preset heating temperature, or decreased to a preset heating temperature.

[0027] 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 unit area includes: a plurality of circles of the heating units are sequentially arranged from the center of the vertical cavity surface emitting laser outward to form a first circle of heating units, a second circle of heating units, a third circle of heating units, a fourth circle of heating units and a fifth circle of heating units, and the corresponding relationship between the temperature difference and the power of each circle of the heating units corresponding to the unit area is as follows:

[0028]

[0029] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0031] Figure 1 is a schematic diagram of a rapid thermal annealing apparatus according to some embodiments of the present invention;

[0032] Figure 2 is a schematic diagram of a vertical cavity surface emitting laser according to some embodiments of the present invention;

[0033] Figure 3 is a schematic diagram of a vertical cavity surface emitting laser according to some other embodiments of the present invention;

[0034] Figure 4 is a schematic diagram of heating and cooling of a wafer according to some embodiments of the present invention;

[0035] Figure 5 is a schematic diagram of a process for adjusting wafer temperature according to some embodiments of the present invention;

[0036] Figure 6 is a schematic diagram of another process for adjusting wafer temperature according to some embodiments of the present invention.

[0037] Reference numerals:

[0038] 100. Rapid thermal annealing device;

[0039] 10. Shell; 11. Reaction chamber; 12. Accommodation 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;

[0040] 20. vertical cavity surface emitting laser; 21. heating unit; 22. sub-heating element;

[0041] 30. Temperature-averaging cover; 31. Cooling chamber; 32. Second signal transmission channel;

[0042] 41. wafer; 42. temperature measuring instrument; 43. support frame;

[0043] 1. The first circle of heating units; 2. The second circle of heating units; 3. The third circle of heating units; 4. The fourth circle of heating units; 5. The fifth circle of heating units. DETAILED DESCRIPTION

[0044] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0045] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are 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 cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0046] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] Reference below Figure 1-Figure 6 A rapid thermal annealing apparatus 100 according to an embodiment of the present invention is described.

[0048] According to the rapid thermal annealing device 100 of the embodiment of the present invention, the rapid thermal annealing device 100 is used for processing the wafer 41. The rapid thermal annealing device 100 is used to perform rapid thermal annealing treatment on the wafer 41, and by rapidly heating the wafer 41, the wafer 41 can achieve specific crystal structure changes, impurity activation, defect repair or other thermal treatment purposes.

[0049] The rapid thermal annealing device 100 includes a shell 10, a vertical cavity surface emitting laser 20 and multiple control modules. A reaction chamber 11 is defined in the shell 10. A wafer 41 is located in the reaction chamber 11. The vertical cavity surface emitting laser 20 is located in the reaction chamber 11. Two vertical cavity surface emitting lasers 20 are provided. The two vertical cavity surface emitting lasers 20 are respectively arranged on both sides of the thickness direction of the wafer 41. The vertical cavity surface emitting laser 20 is used to heat the wafer 41. Both sides of the thickness direction of the wafer 41 can be heated at the same time, with higher heating efficiency and faster heating rate.

[0050] 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 can accurately control the temperature of each heating unit 21. The heating unit 21 is an emitting laser.

[0051] In the related art, most rapid thermal annealing equipment uses halogen lamp as a radiant heat source, and uses a specific wavelength (0.3 um -0.4um) radiant heat source to heat the wafer 41 individually. Due to the presence of grooves and other shapes on the surface of the wafer 41, or the different materials of the wafer 41 lead to different absorption rates of light by the wafer 41. When the same power is used to irradiate the wafer 41, the surface temperatures of different areas of the wafer 41 are different, resulting in uneven temperature inside the wafer 41. This phenomenon of temperature deviation inside the wafer 41 is called pattern load effect (PLE).

[0052] The number of control modules is equal to the number of heating units 21 and corresponds one to one. Each control module is used to control the opening, closing and power size 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, all heating units 21 use the same power to heat the wafer 41, which will cause the temperature at the center of the wafer 41 to be greater than the temperature at the edge. The power of the corresponding heating unit 21 is controlled by the control module so that the wafer 41 obtains different heating powers, and then the temperature of the wafer 41 is controlled so that the temperature of the surface of the wafer 41 is consistent 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 using a vertical cavity surface emitting laser 20 for annealing from the front and back directions of the wafer 41, the temperature difference between the front and back sides of the wafer 41 is close to the same, which can solve the pattern load effect of the wafer 41 caused by annealing in only one direction.

[0053] After each control module controls the corresponding heating unit 21 to be turned 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 to multiple heating units 21, and the power of the heating unit 21 at the corresponding wafer 41 position is independently controlled by the corresponding control module.

[0054] For example, the vertical cavity surface emitting laser 20 may include four heating units 21 , five heating units 21 , six heating units 21 , and the like.

[0055] 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 at this temperature for 4 seconds for annealing, and then slowly cooled.

[0056] According to the rapid thermal annealing device 100 of the embodiment of the present invention, it includes two vertical cavity surface emitting lasers 20, and the two vertical cavity surface emitting lasers 20 are respectively arranged on both sides of 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 of the thickness direction of the wafer 41 at the same time, so that the heating efficiency is higher and the heating rate is faster; the vertical cavity surface emitting lasers 20 are set as a plurality of heating units 21, and the power of the heating units 21 is independently controlled by corresponding control modules, thereby controlling the temperature of the wafer 41, so that the temperature of the surface of the wafer 41 is consistent, so as to eliminate the temperature difference on the surface of the wafer 41, solve the pattern load effect of the wafer 41, and thus improve the annealing quality of the wafer 41.

[0057] According to some embodiments of the present invention, referring to Figure 2-Figure 3 , multiple heating units 21 are sequentially arranged around the center of the vertical cavity surface emitting laser 20, and the multiple heating units 21 are arranged in a surrounding manner, which can facilitate the arrangement of the multiple heating units 21. Alternatively, the multiple heating units 21 are arranged regionally, 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.

[0058] For example, the VCSEL 20 may be circular, rectangular, polygonal or other irregular shapes.

[0059] According to some embodiments of the present invention, referring to Figure 2-Figure 3 Each heating unit 21 includes a plurality of sub-heating elements 22, and the plurality of sub-heating elements 22 are abutted in sequence and arranged in multiple rows and columns, which not only facilitates the arrangement of the sub-heating elements 22, but also avoids gaps between the sub-heating elements 22, which would cause temperature differences on the surface of the wafer 41.

[0060] See attached Figure 2-Figure 3 As shown, Figure 2-Figure 3 A number in the figure represents a sub-heating element 22, and the same number represents the same heating unit 21. Number 1 represents the lowest power of the heating unit 21, and number 5 represents the highest power of the heating unit 21. From number 1 to number 5, the power of the heating unit 21 increases successively. The dotted line in the figure is the position of the vertical projection of the wafer 41.

[0061] Numbers 1 to 5 represent a first circle of heating units 1 , a second circle of heating units 2 , a third circle of heating units 3 , a fourth circle of heating units 4 and a fifth circle of heating units 5 , respectively.

[0062] For example, each sub-heating element 22 can also be controlled by a control module. The sub-heating element 22 is relatively small in size, and the temperature of the wafer 41 at the corresponding position of the sub-heating element 22 can be further precisely controlled, thereby further eliminating the temperature difference on the surface of the wafer 41.

[0063] According to some embodiments of the present invention, referring to Figure 3 , in the direction from the center of the VCSEL 20 to the two sides of the VCSEL 20, the power of the sub-heating element 22 increases successively. Since the surface of the wafer 41 has a certain area, all the heating units 21 use the same power to heat the wafer 41, which will cause the temperature at the center of the wafer 41 to be greater than the temperature at the edge. The control module controls the power of the heating unit 21 corresponding to the center of the wafer 41 to be relatively low, while the power of the heating unit 21 corresponding to the edge of the wafer 41 is controlled to be relatively high, so that the wafer 41 obtains different heating powers, and then controls the temperature of the wafer 41 to eliminate the temperature difference on the surface of the wafer 41, so that the temperature on the surface of the wafer 41 is consistent, which can solve the pattern load effect of the wafer 41.

[0064] According to some embodiments of the present invention, referring to Figure 3 In the direction from the center of the vertical cavity surface emitting laser 20 to the two sides of the vertical cavity surface emitting laser 20, the number of sub-heating elements 22 in each column decreases successively. The positions 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.

[0065] According to some embodiments of the present invention, referring to Figure 2-Figure 3 , the sub-heating element 22 is a polygon, the side length of the sub-heating element 22 is D, and satisfies: 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 is divided small enough, which can further reduce the temperature difference of the wafer 41. The sub-heating element 22 can be rectangular, quadrilateral or pentagonal, etc.

[0066] For example, the side length of the sub-heating element 22 may be 100 um, 300 um, 500 um, 600 um, 700 um or 1000 um, etc.

[0067] According to some embodiments of the present invention, referring to Figure 1-Figure 3 The power of the sub-heating element 22 of each heating unit 21 is equal, so that the temperature of the position where the sub-heating element 22 heats the wafer 41 is also equal, which can further reduce the temperature difference of the wafer 41.

[0068] According to some embodiments of the present invention, referring to Figure 1-Figure 3 , the distance between the VCSEL 20 and the wafer 41 is A, which satisfies: 50 mm ≤ A ≤ 100 mm. Within this range, the VCSEL 20 has a high heating efficiency for the wafer 41. For example, the distance between the VCSEL 20 and the wafer 41 may be 50 mm, 60 mm, 70 mm, 90 mm, or 100 mm.

[0069] According to some embodiments of the present invention, referring to Figure 1 The rapid thermal annealing device 100 also includes a temperature-averaging cover 30, which is located in the shell 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 evenly transmitted to the wafer 41 through the temperature-averaging cover 30, which can improve the heating efficiency of the wafer 41.

[0070] Two temperature-averaging covers 30 are provided, each located on a side of the corresponding VCSEL 20 close to the wafer 41 .

[0071] According to some embodiments of the present invention, referring to Figure 1 The temperature-average cover 30 abuts against the inner wall 13 of the housing 10 to define a housing chamber 12 between the temperature-average cover 30 and the inner wall 13. The vertical cavity surface emitting laser 20 is located in the housing chamber 12. The housing chamber 12 is filled with cooling liquid. The inner wall 13 has a liquid inlet 134 and a liquid outlet 135 connected to the housing chamber 12. When the vertical cavity surface emitting laser 20 is heated, the temperature of the vertical cavity surface emitting laser 20 is high, which is easy to damage the life of the vertical cavity surface emitting laser 20. When the vertical cavity surface emitting laser 20 heats the wafer 41, the cooling liquid is introduced into the housing chamber 12 through the liquid inlet 134, and the cooling liquid is extracted through the liquid outlet 135, so that the flowing cooling liquid cools the vertical cavity surface emitting laser 20, so that the vertical cavity surface emitting laser 20 is kept at a lower 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 may be water.

[0072] According to some embodiments of the present invention, referring to Figure 1 The temperature-averaging cover 30 has a cooling cavity 31 filled with a first cooling gas, and the inner wall 13 has a first air inlet 131 and a first air outlet 132 connected to the cooling cavity 31. The first cooling gas can be delivered to the cooling cavity 31 through the first air inlet 131, and the first cooling gas can be extracted through the first air outlet 132. The flowing first cooling gas can cool the vertical cavity surface emitting laser 20, which can further avoid the problem of over-high temperature when the vertical cavity surface emitting laser 20 is heated. For example, the first cooling gas can be argon, nitrogen, or helium.

[0073] Each temperature-averaging cover 30 has a cooling chamber 31 therein.

[0074] According to some embodiments of the present invention, referring to Figure 1The rapid thermal annealing device 100 also includes a thermometer 42, which is located outside the housing 10. A through hole 133 is formed on the inner wall 13 and is arranged opposite to the thermometer 42. The accommodating cavity 12 has a first signal transmission channel 121 in communication with the through hole 133. The vertical cavity surface emitting laser 20 has a second signal transmission channel 32 in communication with the first signal transmission channel 121. The thermometer 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 hood 30. The temperature hood 30 is a transparent part, so that the laser signal can pass through the temperature hood 30 to reach the surface of the wafer 41, so as to detect the temperature of the wafer 41. The temperature of the wafer 41 can be detected in real time by the thermometer 42, so as to adjust the power of the vertical cavity surface emitting laser 20 according to the temperature of the wafer 41 to heat the wafer 41 in the subsequent step.

[0075] The temperature meter 42 may be a thermocouple or an optical temperature meter, but is not limited thereto.

[0076] According to some embodiments of the present invention, the thermometer 42 is a laser thermometer, which can also detect the temperature of the outer surface of the wafer 41 at different positions, 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 positions, thereby adjusting the temperature of the wafer 41 to improve the temperature uniformity of the wafer 41.

[0077] The laser signal emitted by the thermometer 42 reaches the surface of the wafer 41 , and 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, which is then processed by an electronic circuit to calculate the surface temperature of the wafer 41 .

[0078] There are also two thermometers 42, which are used to detect the temperature of the two side surfaces in the thickness direction of the wafer 41, and feed back the real-time detected temperature to the control module. The control module controls and adjusts the power of each heating unit 21 according to the real-time detected temperature to ensure that the temperature of the two side surfaces in the thickness direction of the wafer 41 is more uniform.

[0079] According to some embodiments of the present invention, referring to Figure 1 A support frame 43 for placing a wafer 41 is provided between the two vertical cavity surface emitting lasers 20. The support frame 43 is used to support the wafer 41. A robot can be used to place the wafer 41 on the support frame 43. After heating, the robot can be used to remove the wafer 41 from the support frame 43.

[0080] According to some embodiments of the present invention, referring to Figure 1The reaction chamber 11 is filled with a first protective gas, and the shell 10 has a second air inlet 14 and a second air outlet 15 connected to the reaction chamber 11. When the wafer 41 is heated, the first protective gas is filled into the reaction chamber 11 to discharge the air in the reaction chamber 11, so as to prevent the wafer 41 from reacting with impurities in the air and causing damage to the wafer 41; furthermore, 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 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, so as to increase the cooling rate of the wafer 41.

[0081] For example, the first protective gas may be argon, nitrogen, or oxygen.

[0082] According to some embodiments of the present invention, referring to Figure 1-Figure 3 The inner surface of the shell 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 a laser to the wafer 41. When the laser is emitted to the metal coating, the metal coating can better reflect the laser, so as to reflect the laser to the wafer 41 and heat the wafer 41.

[0083] For example, the material of the metal coating may be gold or silver. Gold and silver have relatively good reflectivity. It is understandable that the metal coating may also be made of other suitable materials.

[0084] The control method of the wafer rapid thermal annealing device 100 according to the second embodiment of the present invention is applied to the rapid thermal annealing device 100 according to the first embodiment of the present invention. Please refer to Figure 5 , the control method comprises the following steps:

[0085] S101: The vertical cavity surface emitting laser heats the wafer at a preset power;

[0086] S102: Obtaining the heating time of the wafer;

[0087] S103: When the heating time reaches the preset heating time, the measured temperatures of the two side surfaces of the wafer are obtained;

[0088] S104: Obtaining the temperature difference between the measured temperature and the preset heating temperature;

[0089] 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.

[0090] Among them, the preset heating temperature and preset heating time of the wafer 41 can be pre-stored in the control module, and the preset heating temperature can be any temperature between 1000℃ and 1200℃, which can be 1000℃, 1200℃, 1500℃, 1800℃ or 2000℃, and 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 associated with 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 the preset heating time, the preset heating rate is obtained by dividing them, and the preset heating rate can also be set directly. There is a temperature measuring point on each side of the wafer 41, and the temperature of the two temperature measuring points can be detected by the thermometer 42 to obtain the measured temperature of the two sides of the wafer 41.

[0091] 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.

[0092] When the heating time reaches the preset heating time, the actual temperatures of the two sides of the wafer 41 at the preset heating time are obtained. Thermometers 42 are provided on both sides of the wafer 41 in the thickness direction, and the thermometers 42 can obtain the actual temperatures of the two sides of the wafer 41 in real time.

[0093] If the preset heating temperature of the wafer 41 is equal to the actual measured temperature of the wafer 41, there is no need to adjust the power of the vertical cavity surface emitting laser 20; if the actual measured temperature of the wafer 41 is greater than the preset heating temperature of the wafer 41, the power of the vertical cavity surface emitting laser 20 is reduced; if the actual measured temperature of the wafer 41 is less than the preset heating temperature of the wafer 41, the power of the vertical cavity surface emitting laser 20 is increased.

[0094] 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 actually measured temperature, so as to control the heating temperature of the wafer 41 to be within the range of the preset heating temperature.

[0095] 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, and 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.

[0096] 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 100kw for 4 seconds, the measured temperatures on both sides of the wafer 41 are both 1000°C. 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 20kw. The control module controls the overall power of the vertical cavity surface emitting laser 20 to increase by 20kw. Specifically, the power can be evenly distributed to each heating unit 21.

[0097] According to the control method of the rapid thermal annealing device 100 of 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 actual measured temperature, and the heating temperature of the wafer 41 is controlled to accurately reach the preset heating temperature within the preset heating time.

[0098] 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 correspond to the plurality of heating units 21 one by one, wherein S101: the vertical cavity surface emitting laser 20 heats the wafer at a preset power;

[0099] S102: Obtaining the heating time of the wafer;

[0100] S1031: When the heating time reaches the preset heating time, the measured temperature of each unit area is obtained;

[0101] S104: Obtaining the temperature difference between the measured temperature and the preset heating temperature;

[0102] S105: adjusting 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 the two side surfaces of the wafer is increased to a preset heating temperature, or decreased to a preset heating temperature.

[0103] The measured temperature of the unit areas on both sides of the wafer 41 is obtained. The thermometer 42 can detect the temperature of the unit areas on both sides of the wafer 41 in the thickness direction. Each side of the wafer 41 has multiple unit areas. Each unit area can detect the temperature of at least one position, and the measured temperature of the position represents the temperature of the unit area. The thermometer 42 can use a multi-spectral radiation thermometer to measure the temperature of multiple positions at the same time.

[0104] The power of the heating unit 21 of the vertical cavity surface emitting laser 20 corresponding to each unit area of ​​the wafer 41 is adjusted according to the preset heating temperature and the actually measured temperatures at multiple positions, and the actually measured temperatures at multiple positions of the wafer 41 are obtained. Thermometers 42 are provided on both sides of the wafer 41 in the thickness direction, and the power of the heating unit 21 of the vertical cavity surface emitting laser 20 at the corresponding position of the wafer 41 is adjusted according to the difference between the preset temperature and the actually measured temperatures at multiple positions.

[0105] The control module obtains the difference between the preset heating temperature and the actual temperature of each unit area of ​​the wafer 41.

[0106] 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 , and the control module adjusts the power of the heating unit 21 according to the temperature difference and the power adjustment relationship.

[0107] If the preset heating temperature 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 heating temperature of the wafer 41, the power of the heating unit 21 of the vertical cavity surface emitting laser 20 of the corresponding unit area of ​​the wafer 41 is reduced; if the measured temperature of a certain unit area of ​​the wafer 41 is less than the preset heating temperature of the wafer 41, the power of the heating unit 21 of the vertical cavity surface emitting laser 20 of the corresponding unit area of ​​the wafer 41 is increased. The power of the heating unit 21 of the vertical cavity surface emitting laser 20 of the corresponding unit area of ​​the 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 the wafer 41 and improve the temperature uniformity of the wafer 41.

[0108] According to some embodiments of the present invention, referring to 2- Figure 5 , the power of the heating unit 21 corresponding to each unit area is adjusted according to the temperature difference of each unit area, including: a plurality of circles of heating units 21 are sequentially arranged from the center of the vertical cavity surface emitting laser 20 to the outside as a first circle of heating units 1, a second circle of heating units 2, a third circle of heating units 3, a fourth circle of heating units 4 and a fifth circle of heating units 5, and the corresponding relationship between the temperature difference and the power of each circle of heating units 21 corresponding to the unit area is as follows:

[0109] See attached Figure 2 and Figure 3 , the same number represents a heating unit 21.

[0110] Table 1 Power adjustment relationship table

[0111]

[0112] When the preset heating temperature is 1200°C and the preset heating temperature is 4 seconds, after the wafer 41 is heated at the preset power of 100kw for 4 seconds, the measured temperature of the unit area of ​​the wafer 41 is 1000°C, and the temperature difference is -200°C. The unit area corresponds to the second circle heating unit 2 of the heating unit 21. By querying the power adjustment relationship in Table 1, it can be known that the power of the second circle heating unit 2 needs to be increased by 4.9kw.

[0113] When the preset heating temperature is 1200°C and the preset heating temperature is 4 seconds, after the wafer 41 is heated at the preset power of 100kw for 4 seconds, the measured temperature of the unit area of ​​the wafer 41 is 1300°C, and the temperature difference is +100°C. The unit area corresponds to the fourth circle heating unit 4 of the heating unit 21. By querying the power adjustment relationship in Table 1, it can be known that the power of the fourth circle heating unit 4 needs to be reduced by 5.2kw.

[0114] In the description of this specification, the description with reference to the terms "some embodiments", "optionally", "further" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0115] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that 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 shell, wherein a reaction chamber is defined in the shell, and the wafer is located in the reaction chamber; 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, 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 of the corresponding heating unit; A temperature-averaging cover, the temperature-averaging cover is located inside the shell; A thermometer, wherein the thermometer is located outside the shell, the temperature-averaging hood abuts against the inner wall of the shell, a receiving cavity is provided between the temperature-averaging hood and the inner wall, a through hole arranged opposite to the thermometer is formed on the inner wall, a first signal transmission channel connected to the through hole is provided in the receiving cavity, a second signal transmission channel connected to the first signal transmission channel is provided in the vertical cavity surface emitting laser, and the thermometer is used to detect the temperature of the wafer.

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: The temperature-averaging cover is located in the housing 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 vertical cavity surface emitting laser is located in the accommodating cavity, the accommodating cavity is filled with cooling liquid, and the inner wall has a liquid inlet and a liquid outlet communicated with the accommodating 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 inner 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 1, characterized in that: The temperature measuring instrument includes a transmitting unit, the temperature-averaging cover is a transparent member, and the laser signal emitted by the transmitting unit passes through the first signal transmission channel, the second signal transmission channel and the temperature-averaging 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.

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