A hot stage automatic level adjustment device

Abstract

An embodiment of this specification provides a hot stage automatic leveling device, including: a reaction chamber in which a hot stage is placed, and an air inlet for introducing reaction gas is provided at the top of the reaction chamber; an adjustment mechanism for adjusting the level and / or position height of the hot stage; an optical detector disposed directly above the air inlet; and a controller that controls the adjustment mechanism to adjust the level of the hot stage according to the signal emitted by the optical detector. By providing a transmit-receive integrated optical detector directly above the air inlet, a first light beam is emitted from the central position of the optical detector to reach the upper surface of the hot stage, and the hot stage reflects the first light beam to form a second light beam. When the hot stage is level, the second light beam reaches the central position of the optical detector, and when the hot stage is not level, the second light beam reaches the edge region of the optical detector. The controller controls the adjustment mechanism to adjust the level of the hot stage according to the signal emitted by the optical detector.

Description

Technical Field

[0001] This specification relates to the technical field of semiconductor wafer processing, and particularly relates to a hot stage automatic level adjustment device. Background Art

[0002] In some CVD (Chemical Vapor Deposition) processes, such as Plasma Enhanced Chemical Vapor Deposition (PECVD), a reaction chamber for the reaction of gas with the wafer is provided in the corresponding semiconductor processing equipment. A hot stage for loading the wafer is provided in the reaction chamber. The hot stage is equipped with a heating device and can heat the wafer to a specified temperature, so it is called a hot stage (HEATER). The flatness of the bearing surface of the hot stage that bears the wafer determines the flatness of the processed part of the wafer. Therefore, the flatness of the hot stage has a particularly great impact on the process. When the flatness of the hot stage deteriorates, the flatness of the surface of the wafer on the hot stage deteriorates, resulting in poor uniformity of the film deposited on the wafer surface. This is not allowed in the process and may lead to the adverse consequence of wafer scrapping. Summary of the Invention

[0003] In view of this, an embodiment of this specification provides a hot stage automatic level adjustment device. By providing a combined transmitting and receiving optical detector directly above the air inlet, a first light beam is emitted from the central position of the optical detector to the upper surface of the hot stage. The hot stage reflects the first light beam to form a second light beam. When the hot stage is level, the second light beam reaches the central position of the optical detector. When the hot stage is not level, the second light beam reaches the edge area of the optical detector. The optical detector emits different signals according to the position of the received second light beam, and the controller controls the adjustment mechanism to adjust the level of the hot stage according to the signals emitted by the optical detector.

[0004] The embodiment of this specification provides the following technical solutions: A hot stage automatic level adjustment device includes:

[0005] A reaction chamber, in which a hot stage is placed, and an air inlet for introducing reaction gas is provided at the top of the reaction chamber;

[0006] An adjustment mechanism for adjusting the level and / or position height of the hot stage;

[0007] An optical detector, which is arranged directly above the air inlet. The optical detector is a combined transmitting and receiving optical detector. A first light beam is emitted from the central position of the optical detector and passes through the air inlet to reach the upper surface of the hot stage. The optical detector emits different signals according to the position of the second light beam formed by the hot stage reflecting the first light beam. Among them, when the hot stage is level, the second light beam reaches the central position of the optical detector. When the hot stage is not level, the second light beam reaches the edge area of the optical detector;

[0008] A controller, the controller is at least coupled to an optical detector, and the controller controls the adjustment mechanism to adjust the level of the hot stage according to the signal emitted by the optical detector.

[0009] Preferably, the optical detector includes a transmitting and receiving integrated probe and an optical fiber. The integrated probe is electrically connected to the optical fiber, and the transmitting end of the optical fiber is directly above the air inlet.

[0010] Preferably, the optical fiber includes at least seven cores. Any one of the cores is in contact with its adjacent cores. A core at the center position of the optical fiber emits the first light beam, and the spot diameter of the first light beam is the same as the diameter of the core.

[0011] Preferably, when the hot stage is horizontal, the second light beam coincides with the first light beam. When the hot stage is tilted, the included angle between the second light beam and the first light beam is twice the tilt angle of the hot stage.

[0012] Preferably, the tilt angle of the hot stage is calculated according to the position where the second light beam reaches the optical fiber. The calculation formula is:

[0013] tan2α = X / Y,

[0014] where α is the angle between the hot stage and the horizontal plane, X is the distance between the core at the center position of the optical fiber and the core where the second light beam arrives, and Y is the distance between the core at the center position of the optical fiber and the hot stage.

[0015] Preferably, the number of cores is 21. One of the cores is at the center position of the optical fiber, and the remaining 20 cores are symmetrically distributed with respect to the core at the center position.

[0016] Preferably, the integrated probe is a 22-T-0000 integrated probe, and the optical fiber is an SMA905 optical fiber.

[0017] Preferably, a driving mechanism is connected to the optical detector, and the driving mechanism can drive the optical detector to move relative to the reaction chamber along the horizontal and / or vertical directions.

[0018] Preferably, the adjustment mechanism is a three-axis lifting mechanism. The controller is connected to control the three-axis lifting mechanism. The three-axis lifting mechanism includes three elevators evenly distributed around the center of the hot stage, and all three elevators are hinged to the hot stage.

[0019] Preferably, the elevator includes a motor, a lead screw, and a lifting block. The output end of the motor is connected to the lead screw, the lead screw is screwed to the lifting block, and the lifting block is hinged to the hot stage.

[0020] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above technical solutions adopted in the embodiments of the present specification at least include:

[0021] By arranging a transmitting and receiving integrated optical detector directly above the air inlet, a first light beam is emitted from the central position of the optical detector to reach the upper surface of the hot stage. The hot stage reflects the first light beam to form a second light beam. When the hot stage is horizontal, the second light beam reaches the central position of the optical detector. When the hot stage is not horizontal, the second light beam reaches the edge area of the optical detector. The optical detector emits different signals according to the position of the received second light beam, and the controller controls the adjusting mechanism to adjust the levelness of the hot stage according to the signals emitted by the optical detector. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 It is a schematic structural diagram of a hot stage automatic leveling device provided by the present application;

[0024] Figure 2 It is a schematic principle diagram of the optical detector of the hot stage automatic leveling device provided by the present application;

[0025] Figure 3 It is a schematic diagram when the hot stage of the hot stage automatic leveling device provided by the present application is horizontal;

[0026] Figure 4 It is a schematic diagram when the hot stage of the hot stage automatic leveling device provided by the present application is tilted;

[0027] Figure 5 It is a schematic diagram of the principle of calculating the tilt angle when the hot stage of the hot stage automatic leveling device provided by the present application is tilted;

[0028] Figure 6 It is a schematic diagram when the light spot of the hot stage automatic leveling device provided by the present application is too small or too large;

[0029] Figure 7 It is a schematic diagram of seven-core optical fibers of the hot stage automatic leveling device provided by the present application;

[0030] Figure 8 It is a schematic structural diagram of the adjusting mechanism of the hot stage automatic leveling device provided by the present application.

[0031] In the figure, 1 is a reaction chamber; 2 is an air inlet; 3 is a hot stage; 4 is an optical detector; 41 is an integrated probe; 42 is an optical fiber; 421 is a first core; 422 is a second core; 5 is a controller; 6 is a first light beam; 7 is a second light beam; 8 is a three-axis lifting mechanism; 81 is a motor; 82 is a lead screw; 83 is a lifting block. Detailed implementation manners

[0032] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0033] The following uses specific specific examples to illustrate the implementation manners of the present application. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation manners. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application.

[0034] It should be noted that the following describes various aspects of the embodiments within the scope of the appended claims. It should be obvious that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on the present application, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects described herein can be used to implement the device and / or practice the method. In addition, this device and / or this method can be implemented using other structures and / or functions in addition to one or more of the aspects described herein.

[0035] It should also be noted that the drawings provided in the following embodiments only schematically illustrate the basic concept of the present application. The drawings only show the components related to the present application, rather than being drawn according to the number, shape and size of the components in actual implementation. The type, quantity and proportion of each component in its actual implementation can be an arbitrary change, and the component layout type may also be more complex.

[0036] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0037] In some CVD (Chemical Vapor Deposition) processes, such as Plasma Enhanced Chemical Vapor Deposition (PECVD), a reaction chamber for the reaction of gas with the wafer is provided in the corresponding semiconductor processing equipment. A hot stage for loading the wafer is provided in the reaction chamber. The flatness of the bearing surface of the hot stage that bears the wafer determines the flatness of the processed part of the wafer. Therefore, the flatness of the hot stage has a particularly great impact on the process. When the flatness of the hot stage deteriorates, the flatness of the surface of the wafer on the hot stage will deteriorate, resulting in poor uniformity of the film deposited on the wafer surface, which is not allowed in the process and may lead to the adverse consequence of wafer scrapping.

[0038] Currently, the detection of the flatness of the hot stage is mainly by manual visual observation, resulting in large errors in the detection results. Although some instruments can be used for auxiliary detection, these instruments generally need to enter the interior of the reaction chamber, and the interior of the reaction chamber is often in a high-temperature state, which is likely to cause damage to the instruments, and the detection process is generally relatively complex.

[0039] The inventor has conducted extensive and in-depth experiments and designed an automatic hot stage leveling device.

[0040] The following will describe the technical solutions provided by the embodiments of the present application with reference to the accompanying drawings.

[0041] As Figures 1-8 shown, an automatic hot stage leveling device includes:

[0042] A reaction chamber 1, in which a hot stage 3 is placed, and an air inlet 2 for introducing reaction gas is provided at the top of the reaction chamber 1;

[0043] An adjustment mechanism for adjusting the flatness and / or position height of the hot stage 3;

[0044] An optical detector 4 is provided directly above the air inlet 2. The optical detector 4 is an integrated emission and reception optical detector. A first light beam 6 is emitted from the central position of the optical detector 4 through the air inlet 2 to reach the upper surface of the hot stage 3. The optical detector 4 emits different signals according to the position of the second light beam 7 formed by the hot stage 3 reflecting the first light beam 6. Among them, when the hot stage 3 is level, the second light beam 7 reaches the central position of the optical detector 4, and when the hot stage 3 is not level, the second light beam 7 reaches the edge area of the optical detector 4;

[0045] A controller 5 is at least coupled to the optical detector 4. The controller 5 controls the adjustment mechanism to adjust the flatness of the hot stage 3 according to the signal emitted by the optical detector 4.

[0046] By arranging an integrated transmitting and receiving optical detector directly above the air inlet 2, a first light beam 6 is emitted from the central position of the optical detector 4. The first light beam 6 passes through the air inlet 2 and reaches the upper surface of the hot stage 3. The hot stage 3 reflects the first light beam 6 to form a second light beam 7. When the hot stage 3 is horizontal, the second light beam 7 moves vertically to reach the central position of the optical detector 4. When the hot stage 3 is not horizontal, a certain angle is formed between the second light beam 7 and the first light beam 6, and the second light beam 7 reaches the edge area of the optical detector 4. The optical detector 4 emits different signals according to the position of the received second light beam 7. The controller 5 controls the adjusting mechanism to adjust the levelness of the hot stage 3 according to the signals emitted by the optical detector 4, which can meet the requirement of real-time detecting the levelness of the hot stage 3 and making adjustments, avoid wafer scrapping, and improve the processing yield.

[0047] It should be noted that the optical detector 4 is arranged outside the reaction chamber 1 and does not extend into the reaction chamber 1. The high temperature inside the reaction chamber 1 will not affect the optical detector 4, and the light beam emitting end of the optical detector 4 is directly above the air inlet 2, ensuring that the first light beam 6 emitted by the optical detector 4 can irradiate the upper surface of the hot stage 3 along the vertical direction.

[0048] As Figures 1-5 shown, in some embodiments, the optical detector 4 includes an integrated transmitting and receiving probe 41 and an optical fiber 42. The integrated probe 41 is electrically connected to the optical fiber 42. The emitting end of the optical fiber 42 is directly above the air inlet 2. The optical detector 4 is composed of the integrated transmitting and receiving probe 41 and the optical fiber 42. The emitting end of the optical fiber 42 is directly above the air inlet 2, ensuring that the light beam emitted by the optical fiber 42 can irradiate the hot stage 3 along the vertical direction.

[0049] It should be noted that the detection signal (the first light beam 6) is provided by a pulsed Xe lamp light source. The light intensity of this light source is adjustable and stable, and the optical path is straight, ensuring that the first light beam 6 can irradiate the upper surface of the hot stage 3 along the vertical direction. An optical fiber optical path is built, and the detection signal starts from the light source and is incident on the surface of the hot stage 3 through the optical fiber 42.

[0050] As Figures 3-7As shown, in some embodiments, the optical fiber 42 includes at least seven cores, and any one of the cores is in contact with its adjacent cores. A core located at the center of the optical fiber 42 emits the first light beam 6, and the spot diameter of the first light beam 6 is the same as the diameter of the core. To ensure a relatively large area for receiving the reflected second light beam 7 and being able to capture the reflected second light beam 7, at least seven cores are provided, with one core in the middlemost position. For the sake of easy understanding, the core in the middle position is named the first core 421, and the remaining cores are second cores 422. The first core 421 and the second cores 422 have the same diameter. The first core 421 is used to emit the first light beam 6, and the remaining six second cores 422 are evenly distributed around the first core 421. The first core 421 is in contact with all the six second cores 422. The diameter of the first light beam 6 is adjusted to be the same as the diameter of the first core 421 to ensure the detection effect. If the spot is too small, the reflected signal (the second light beam 7) will always be received by a certain core; if the spot is too large, all the cores can always receive the reflected signal.

[0051] It should be noted that in practical applications, the optical detection signal cannot be infinitely small to become a straight line but is a light beam. Therefore, there will be differences in the size of the light beam (i.e., the spot size), and the spot can be controlled. Thus, it can be achieved that some optical fibers receive the reflected signal while some do not.

[0052] As Figures 3-4 shown, in some embodiments, when the hot stage 3 is horizontal, the second light beam 7 coincides with the first light beam 6. When the hot stage 3 is tilted, the included angle between the second light beam 7 and the first light beam 6 is twice the tilt angle of the hot stage 3. When the hot stage 3 is horizontal, since the first light beam 6 is vertically irradiated onto the hot stage 3, the reflected second light beam 7 will necessarily be along the vertical direction (i.e., the second light beam 7 coincides with the first light beam 6), and the second light beam 7 will irradiate to the emitting position of the first light beam 6. When the hot stage 3 is tilted, the first light beam 6 is irradiated along the vertical direction. Since the first light beam 6 is no longer perpendicular to the upper surface of the hot stage 3, there must be an included angle between the reflected second light beam 7 and the first light beam 6. According to the reflection principle, the included angle between the second light beam 7 and the first light beam 6 is twice the included angle between the hot stage 3 and the horizontal plane.

[0053] As Figure 5 shown, in some embodiments, the tilt angle of the hot stage 3 is calculated based on the position where the second light beam 7 reaches the optical fiber 42. The calculation formula is:

[0054] tan2α = X / Y,

[0055] Wherein, α is the angle between the hot stage 3 and the horizontal plane, X is the distance between the core at the center position of the optical fiber and the core reached by the second light beam, and Y is the distance between the core at the center position of the optical fiber and the hot stage.

[0056] The first light beam 6 is vertically downward. Therefore, the distance between the first light beam 6, the second light beam 7 and the core at the center position of the optical fiber 42 and the core reached by the second light beam 7 can be directly characterized by a right triangle. According to the above formula, it can be known that only by knowing the distance Y between the core at the center position of the optical fiber 42 and the hot stage 3 and the distance X between the core at the center position of the optical fiber 42 and the core reached by the second light beam 7, the tilt angle of the hot stage 3 can be calculated. Since Y is a constant value, the tilt angle of the hot stage 3 can be calculated based on the value of X.

[0057] As Figure 5 shown, in some embodiments, the number of cores is 21. One of the cores is at the center position of the optical fiber 42 (the first core 421), and the remaining 20 cores (the second cores 422) are symmetrically distributed with respect to the core at the center position (the first core 421). When the spot size is determined, the more cores there are, the more accurate the calculation is, which can ensure the accuracy of the calculation.

[0058] As Figures 1-2 shown, in some embodiments, the integrated probe 41 is a 22-T-0000 integrated probe, and the optical fiber 42 is an SMA905 optical fiber. By using the 22-T-0000 integrated probe, miniaturization of volume and light weight are achieved. By using the SMA905 optical fiber, the coupling performance is good and the light transmission rate is high.

[0059] In some embodiments, a driving mechanism is connected to the optical detector 4. The driving mechanism can drive the optical detector 4 to move relative to the reaction chamber 1 along the horizontal and / or vertical directions. By providing the driving mechanism, when the reaction chamber 1 needs to be opened, the optical detector 4 can be moved away through the driving mechanism, which is convenient for opening the cover of the reaction chamber 1.

[0060] As Figure 8 shown, in some embodiments, the adjusting mechanism is a three-axis lifting mechanism 8. The controller 5 is connected to control the three-axis lifting mechanism 8. The three-axis lifting mechanism 8 includes three elevators evenly distributed around the center of the hot stage 3. The three elevators are all hinged to the hot stage 3. By providing the three-axis lifting mechanism 8, when the hot stage 3 needs to be lifted, the controller 5 controls the three lifting mechanisms to work synchronously with equal lifting speeds, and the hot stage 3 can be lifted steadily. When the hot stage 3 needs to be leveled, the controller 5 can make the lifting speeds of the three elevators different, that is, the lifting heights are different, so as to compensate for the deflection angle of the hot stage 3.

[0061] As Figure 8As shown, in some embodiments, the elevator includes a motor 81, a lead screw 82, and a lifting block 83. The output end of the motor 81 is connected to the lead screw 82. The lead screw 82 is screwed to the lifting block 83. The lifting block 83 is hinged to the hot stage 3. By using the motor 81 and the lead screw 82 to control the lifting, the lifting accuracy can be ensured. The motor 81 drives the lead screw 82 to rotate, and the lifting block 83 moves along the lead screw 82. The lifting block 83 drives the hot stage 3 to move, and the lifting or leveling operation of the hot stage 3 can be realized.

[0062] It should be noted that in other embodiments, the elevator can also adopt lifting structures such as cylinders and electric telescopic rods, which can be selected according to the actual situation.

[0063] For the same or similar parts among the various embodiments in this specification, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the method embodiments described later, since they correspond to the system, the description is relatively simple, and the relevant parts can be referred to the partial description of the system embodiments.

[0064] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A device for automatically adjusting the level of a hot stage, characterized in that: The device is applied to a CVD process, and comprises: A reaction chamber, wherein a hot plate is placed in the reaction chamber, and an air inlet for introducing reaction gas is opened at the top of the reaction chamber; An adjusting mechanism, the adjusting mechanism is used to adjust the horizontality and / or position height of the heating platform; An optical detector, the optical detector is arranged just above the air inlet, the optical detector is a transmitting and receiving integrated optical detector, the center position of the optical detector emits a first light beam that passes through the air inlet and reaches the upper surface of the heat platform, and the optical detector sends different signals according to the position of a second light beam formed by the heat platform reflecting the first light beam, wherein when the heat platform is horizontal, the second light beam reaches the center position of the optical detector, and when the heat platform is not horizontal, the second light beam reaches the edge area of ​​the optical detector; A controller, the controller being coupled to at least the optical detector, and the controller controlling the adjustment mechanism to adjust the horizontality of the heat stage according to a signal sent by the optical detector; The regulating mechanism is a three-axis lifting mechanism, the controller controls and connects the three-axis lifting mechanism, the three-axis lifting mechanism includes three groups of lifts evenly distributed around the center of the heating platform, and the three groups of lifts are hinged to the heating platform.

2. The automatic level adjustment device for a hot stage according to claim 1, characterized in that: The optical detector comprises a transmitting and receiving integrated probe and an optical fiber. The integrated probe is electrically connected to the optical fiber, and the transmitting end of the optical fiber is located directly above the air inlet.

3. The automatic level adjustment device for a hot stage according to claim 2, characterized in that: The optical fiber includes at least seven cores, any of the cores is in contact with its adjacent cores, a core located at the center of the optical fiber emits the first light beam, and the spot diameter of the first light beam is the same as the diameter of the core.

4. The automatic level adjustment device for a hot stage according to claim 3, characterized in that: When the heating stage is horizontal, the second light beam coincides with the first light beam, and when the heating stage is tilted, the angle between the second light beam and the first light beam is twice the tilt angle of the heating stage.

5. The automatic level adjustment device for a heating platform according to claim 4, characterized in that: The tilt angle of the heat stage is calculated according to the position where the second light beam reaches the optical fiber, and the calculation formula is: tan2α=X / Y, Wherein, α is the angle between the heat stage and the horizontal plane, X is the distance between the core at the center of the optical fiber and the core where the second light beam arrives, and Y is the distance between the core at the center of the optical fiber and the heat stage.

6. The automatic level adjustment device for a heating platform according to claim 3, characterized in that: The number of the fiber cores is 21, one of which is located at the center of the optical fiber, and the remaining 20 fiber cores are symmetrically distributed about the core at the center.

7. The automatic level adjustment device for a heating platform according to claim 2, characterized in that: The integrated probe is a 22-T-0000 integrated probe, and the optical fiber is a SMA905 optical fiber.

8. The automatic level adjustment device for a heating platform according to claim 1, characterized in that: The optical detector is connected to a driving mechanism, and the driving mechanism can drive the optical detector to move along a horizontal and / or vertical direction relative to the reaction chamber.

9. The automatic level adjustment device for a heating platform according to claim 1, characterized in that: The lift comprises a motor, a screw rod and a lifting block, the output end of the motor is connected to the screw rod, the screw rod is screwed to the lifting block, and the lifting block is hinged to the heating platform.

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