Detection device suitable for wafer bearing piece levelness detection

Abstract

The utility model provides a detection device suitable for wafer bearing piece levelness detection, the detection device is arranged on the periphery of a wafer bearing piece in the horizontal direction so as to detect the levelness of the wafer bearing piece, the detection device comprises at least one detection assembly, the detection assembly comprises a laser emitting element and a laser receiving element which are oppositely arranged, and a detection light beam emitted by the laser emitting element is propagated above the wafer bearing piece along the horizontal direction. Based on the detection assembly in the detection device, whether the levelness of the wafer bearing part meets the requirement can be rapidly and conveniently measured according to whether the laser receiving element can receive the detection light beam emitted by the laser emitting element, and the levelness detection and calibration efficiency of the wafer bearing part is effectively improved. And the bearing assembly and the multiple groups of detection assemblies are arranged, and / or the detection device and the wafer bearing piece are rotatably arranged, so that the detection efficiency is further improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of integrated circuit manufacturing equipment components, and relates to a detection device suitable for detecting the levelness of a wafer carrier. Background Art

[0002] In the semiconductor device processing technology, there are multiple heating or high-temperature treatment processes. For example, key processes such as thermal oxidation, impurity diffusion, annealing, and rapid thermal processing. In the above processes, the wafer needs to be placed in the corresponding machine chamber for heating. In order to ensure the overall heat uniformity of the wafer, it is usually necessary to set the wafer to rotate for heating. The thermal uniformity of the wafer can be fed back through the thickness (THK) distribution simulation diagram and the resistivity (RS) distribution simulation diagram (both are simply referred to as the map diagram).

[0003] Please refer to Figure 1 and Figure 2 , which are respectively schematic diagrams showing two common effects of uneven heating after the wafer performs the heating process (i.e., the map diagram). Since the probes participating in temperature control inside the machine are distributed along the radius direction of the wafer, when the internal temperature distribution uniformity of the machine itself is not good, it will cause the map diagram obtained after the wafer performs the heating process to present Figure 1 the ring-shaped symmetric morphology shown in, and by selecting appropriate temperature compensation measures (for example, adaptive adjustment of process parameters), the heat uniformity during wafer processing can be effectively improved. However, even with temperature compensation measures, the problem of poor thermal uniformity shown in Figure 2 cannot be improved. After analysis, it is considered that the wafer is usually supported by a wafer carrier in the machine chamber. The levelness of the wafer carrier is directly related to the heat uniformity of the wafer. If there is a deviation in the levelness of the wafer carrier, it will present Figure 2 the distribution morphology with one side high and the other side low (skew morphology) shown in. Therefore, the problem of poor thermal uniformity caused by the hardware problem of the levelness of the wafer carrier cannot be improved by temperature compensation measures such as process parameter adjustment, and it is necessary to open the chamber to correct the levelness of the wafer carrier or directly replace the wafer carrier to solve it.

[0004] Currently, when the situation is as Figure 2When looking at the map diagram shown, it is usually necessary to visually identify the levelness of the wafer carrier after opening the cavity. This process mainly depends on the subjective judgment of the engineer. The judgment accuracy is affected by the engineer's experience and other uncontrollable factors. This results in the situation that after calibrating the levelness of the wafer carrier based on the judgment result and performing the heating process on the wafer after resuming the machine, the collected wafer map still has a deformed appearance or a serious deviation, so further rework is required to recalibrate the levelness of the wafer carrier, and then repeat the above steps once or even multiple times until the map is normal. This process takes a long time (including calibrating the wafer carrier, stopping the machine and opening the cavity, resuming the machine after calibration, etc.), the work efficiency is low, and it will cause the overall process load to increase, consuming a large amount of manpower and man-hours, and not meeting the high-efficiency and high-convenience requirements of the production line.

[0005] Therefore, how to provide a detection device suitable for detecting the levelness of the wafer carrier to improve the efficient detection of the levelness of the wafer carrier has become an important technical problem that needs to be solved urgently by those skilled in the art.

[0006] It should be noted that the above introduction of the technical background is only for the convenience of clearly and completely explaining the technical solutions of the present application and facilitating the understanding of those skilled in the art. It cannot be considered that the above technical solutions are well-known to those skilled in the art just because these solutions are described in the background art part of the present application. Summary of the Invention

[0007] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a detection device suitable for detecting the levelness of the wafer carrier, which is used to solve the problems of cumbersome process and low efficiency in the levelness measurement and calibration of the wafer carrier in the prior art.

[0008] To achieve the above object and other related objects, the present invention provides a detection device suitable for detecting the levelness of the wafer carrier. The detection device is arranged around the wafer carrier in the horizontal direction to detect the levelness of the wafer carrier. The detection device includes at least one detection component. The detection component includes a laser emitting element and a laser receiving element that are arranged on both sides of the wafer carrier and face each other. The detection beam emitted by the laser emitting element propagates in the horizontal direction above the wafer carrier.

[0009] Optionally, the detection device includes a plurality of the detection components, and a preset angle is formed between the arrangement directions of two adjacent detection components.

[0010] Optionally, the detection device includes four detection components, and a 45° angle is formed between the arrangement directions of two adjacent detection components.

[0011] Optionally, the detection device further includes a carrier assembly, and both the laser emitting element and the laser receiving element are disposed on the carrier assembly.

[0012] Optionally, the wafer carrier includes an edge ring, and the edge ring is provided with a carrier groove vertically penetrating through the edge ring to carry the wafer.

[0013] Optionally, the laser emitting element and the laser receiving element in the same detection assembly are axially symmetric about the vertical center axis of the edge ring.

[0014] Optionally, the detection device is rotatably disposed relative to the wafer carrier.

[0015] Optionally, the distance between the propagation path of the detection beam and the upper surface of the wafer carrier is less than or equal to one tenth of the spot diameter of the detection beam.

[0016] Optionally, the laser emitting element includes at least one of a semiconductor laser and a microcavity laser, and the diameter of the detection beam is in the micrometer range.

[0017] Optionally, the wafer carrier is disposed in a semiconductor machine tool, and the semiconductor machine tool includes a heat treatment machine tool.

[0018] As described above, the detection device for detecting the levelness of a wafer carrier according to the present invention includes at least one detection assembly. The detection assembly includes a laser emitting element and a laser receiving element that are arranged on both sides of the wafer carrier and face each other. By determining whether the laser receiving element can receive the detection beam emitted by the laser emitting element, a quick and convenient measurement of whether the levelness of the wafer carrier meets the requirements can be achieved, effectively improving the efficiency of detecting and calibrating the levelness of the wafer carrier. In addition, by providing a carrier assembly, multiple groups of detection assemblies, and / or rotatably arranging the detection device relative to the wafer carrier, the detection efficiency can be further improved. Description of the Drawings

[0019] Figure 1 It shows a schematic diagram of the effect of uneven heating of the wafer in the semiconductor machine tool due to uneven internal temperature distribution of the machine tool.

[0020] Figure 2 It shows a schematic diagram of the effect of uneven heating of the wafer in the semiconductor machine tool due to the non - compliance of the levelness of the wafer carrier.

[0021] Figure 3 It shows a schematic diagram of the first rotation mode when the detection device for detecting the levelness of the wafer carrier according to the present invention is disposed around the wafer carrier for levelness measurement.

[0022] Figure 4The schematic diagram of the overall structure when the wafer carrier detected by the detection device suitable for detecting the levelness of the wafer carrier of the present invention is an edge ring.

[0023] Figure 5 The schematic diagram of the structure when the wafer carrier detected by the detection device suitable for detecting the levelness of the wafer carrier of the present invention carries a wafer.

[0024] Figure 6 The schematic diagram of the second rotation mode when the detection device suitable for detecting the levelness of the wafer carrier of the present invention is set around the wafer carrier for levelness measurement.

[0025] Figure 7 Shown as Figure 5 The front view schematic diagram of the shown structure.

[0026] Figure 8 The schematic diagram of the overall structure when the detection device suitable for detecting the levelness of the wafer carrier of the present invention includes a plurality of detection components.

[0027] Figure 9 Shown as Figure 8 The top view schematic diagram of the detection device in.

[0028] Explanation of reference numerals

[0029] 10 Detection device

[0030] 11 Detection component

[0031] 111 Laser emitting element

[0032] 112 Laser receiving element

[0033] 113 Detection beam

[0034] 12 Carrying component

[0035] 20 Wafer carrier

[0036] 21 Upper surface

[0037] 30 Wafer Detailed implementation manners

[0038] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0039] Please refer toFigures 1 to 9 It should be noted that the illustrations provided in this embodiment only schematically illustrate the basic concept of the present utility model. Therefore, only the components related to the present utility model are shown in the drawings, 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 actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0040] The present utility model provides a detection device suitable for detecting the levelness of a wafer carrier. Please refer to Figure 3 , which shows a schematic diagram of the first rotation mode when the detection device is arranged around the wafer carrier for levelness measurement. The detection device 10 is arranged horizontally around the wafer carrier 20 to detect the levelness of the wafer carrier 20 (that is, in terms of the vertical projection, the vertical projection of the wafer carrier 20 is located in the inner area of the vertical projection of the detection device 10). The detection device 10 includes at least one detection component 11. The detection component 11 includes a laser emission element 111 and a laser reception element 112 that are arranged on both sides of the wafer carrier 20 and face each other. The detection beam 113 emitted by the laser emission element 111 propagates horizontally above the wafer carrier 20. Here, "arranged to face each other" means that the emission port (not shown) of the laser emission element 111 faces the reception port (not shown) of the laser reception element 112, so that the detection beam 113 can be received by the reception port after being emitted from the emission port.

[0041] Specifically, by arranging the detection device at the periphery in the horizontal direction of the wafer carrier and the detection light beam propagating horizontally above the wafer carrier, when the levelness of the wafer carrier meets the requirements (the upper surface of the wafer carrier is approximately parallel to the horizontal plane, or the included angle with the horizontal plane is extremely small and within the allowable range of process errors), the detection light beam emitted by the laser emitting element can be directly collected by the laser receiving element; while when the levelness of the wafer carrier does not meet the requirements (the upper surface of the wafer carrier undergoes an inclined deformation outside the allowable range of process errors, since the wafer carrier needs to stably carry the wafer and is usually made of a rigid material, the deformation of the upper surface of the wafer carrier means that the entire wafer carrier undergoes the same deformation), the path of the detection light beam emitted by the laser emitting element to the laser receiving element cannot be collected by the laser receiving element due to the obstruction caused by the wafer carrier. Therefore, whether the laser receiving element can receive the detection light beam emitted by the corresponding laser emitting element can be used to quickly and efficiently detect whether the levelness of the wafer carrier meets the requirements. In addition, the detection of whether the wafer carrier meets the levelness requirements using the detection light beam can be carried out during the cavity opening. When it is detected that the levelness of the wafer carrier does not meet the requirements, its levelness is calibrated and then the detection device is used for rapid re-detection until the requirements are met (secondary confirmation can also be carried out after loading the wafer). During this process, redundant processes such as repeating cavity opening, resuming the machine to execute the process, and collecting the map for verification are not required, effectively improving the efficiency of detection and calibration and greatly saving the time and cost of engineers in dealing with this problem.

[0042] As an example, please refer to Figure 4 , which shows a schematic structural diagram when the wafer carrier is an edge ring. The wafer carrier 20 includes an edge ring, and the edge ring is provided with a carrying groove (not marked in the drawing) that vertically penetrates the edge ring to carry the wafer 30. Please refer to Figure 5, shown as a schematic diagram of the overall structure when the edge ring is carrying the wafer. When the wafer 30 enters the semiconductor machine to perform a process, the wafer 30 is placed in a carrier groove for fixation (the side wall of the carrier groove has steps to support the wafer 30), and the heating element in the semiconductor machine can heat the wafer 30 whether it is arranged above or below the edge ring. Since the edge ring is in a ring structure, the mechanical structure stability may be inferior to that of a wafer carrier with a planar structure, so it is more likely to undergo tilting deformation. When the wafer is supported by the edge ring, the edge position of the wafer contacts the edge ring, which makes the influence of the levelness of the edge ring on the wafer more prominent during the heating process. Therefore, the levelness detection of the edge ring is particularly important for ensuring process yield and product performance. In addition, when the wafer carrier is an edge ring, the installation accuracy required for the edge ring needs to be in the millimeter range with an overall height difference within 1 cm, and the levelness of the edge ring can be detected with high precision by the detection device. For example, if the installation accuracy of the edge ring itself within 1 mm can meet the process requirements, then the detection device needs to be able to detect the levelness difference in the millimeter range to achieve the levelness detection of the edge ring.

[0043] As an example, such as Figure 3 shown, the detection device 10 further includes a carrier assembly 12, and both the laser emitting element 111 and the laser receiving element 112 are arranged on the carrier assembly 12. Specifically, the carrier assembly 12 is used to fix the detection assembly 11 so that the laser emitting element 111 and the laser receiving element 112 can always be in the same horizontal plane and face each other, avoiding rearranging the laser emitting element 111 and the laser receiving element 112 and adjusting their positions to be in the same horizontal plane before each levelness detection of the wafer carrier 20. That is, during detection, the detection device is directly arranged outside the wafer carrier and the switches of the laser emitting element and the laser receiving element are turned on to start the detection, which can improve the detection efficiency and detection accuracy.

[0044] In a specific example, such as Figure 3 shown, the carrier assembly 12 is in a ring shape (for example, a circular ring shape), and the laser emitting element 111 and the laser receiving element 112 are arranged on opposite sides of the carrier assembly 12, so that when the detection device 10 is arranged outside the wafer carrier 20, the wafer carrier 20 is located in the area between them. And more preferably, the carrier assembly 12 is telescopically adjustable in the circumferential direction to be applicable to the levelness detection of wafer carriers 20 of different sizes, improving the utilization rate of the detection device and reducing the detection cost.

[0045] As an example, the detection device 10 is rotatably arranged relative to the wafer carrier 20. For example, such as Figure 3As shown, it is possible to set the wafer carrier 20 to be fixed while the detection device 10 rotates, or, as Figure 6 shown, it is possible to set the detection device 10 to be fixed while the wafer carrier 20 rotates, or both can rotate but at different speeds or in different directions. Since the wafer is usually rotated by the wafer carrier to ensure uniform heating during the processing in the semiconductor machine, it is preferably the wafer carrier that rotates. At this time, the detection device can be arranged on the inner wall of the machine chamber corresponding to the periphery of the wafer carrier 20, without the need to additionally arrange other driving mechanisms connected to the detection device and driving it to perform rotational motion, thus saving costs. Of course, in some machines where the wafer carrier is fixedly arranged, the detection device can also be driven to rotate by a driving mechanism.

[0046] Specifically, when the wafer carrier undergoes an inclined deformation in a certain direction, resulting in the non-compliance of the levelness in this direction, if the detection device only includes one detection component, and the direction of non-compliance of the levelness is unknown, the setting direction of the detection component may not be consistent with this direction. At this time, if the positions between the wafer carrier and the detection device are set to be fixed, it may lead to inaccurate detection results, or it may be necessary to repeatedly adjust the setting direction of the wafer carrier multiple times to achieve the detection of the overall levelness. By setting the two to be relatively rotatable, enabling one to rotate relative to the other, the levelness of all directions on the entire upper surface of the wafer carrier can be detected, ensuring the detection accuracy while improving the detection efficiency. In addition, setting the two to be relatively rotatable can also detect the local non-inclined deformation problems that the wafer carrier may occur in the long-term high-temperature working environment.

[0047] As an example, the diameter of the detection beam 113 includes the micron order of magnitude. To avoid ambiguity, the "micron order of magnitude" refers to 10 to 100 μm. When the diameter of the detection beam 113 is relatively large, the following situation will occur: when the level deviation from the qualified requirement is relatively large, the wafer carrier 20 blocks most of the detection beam 113, but a small part of the detection beam 113 can still be received by the laser receiving element 112, thus affecting the detection result. Therefore, limiting the detection beam 113 within the above range can achieve accurate measurement of whether the level meets the requirements. Of course, in other embodiments, the diameter of the detection beam 113 can also be greater than the micron order of magnitude. At this time, the standard for the level to meet the requirements needs to be defined by the ratio of the beam intensity received by the laser receiving element 112 to the beam emitted by the laser emitting element 111. Compared with directly limiting the detection beam 113 to the micron order of magnitude, the complexity of determining the detection result is increased. That is, in this detection device, the spot size and the beam intensity can be used for auxiliary judgment at the same time. Initially, the standard spot size and beam intensity of the collected laser beam are set, and it is preferably to check and calibrate the initial value before each use to prevent the attenuation of the laser itself from affecting the detection accuracy. After the laser detection element receives the laser, analyzing the spot size and / or the double beam intensity of the laser beam can achieve detection of whether the level meets the requirements and even the specific level value.

[0048] As an example, the laser emitting element 111 includes at least one of a semiconductor laser and a microcavity laser, so that the diameter of the detection beam 113 meets the micron order of magnitude requirement; the laser receiving element 112 includes a photodiode (for example, an avalanche photodiode), which can achieve accurate measurement of weak optical signals. Of course, in other embodiments, the laser emitting element 111 can adopt other devices that can emit the detection light 113 with the micron order of magnitude.

[0049] As an example, please refer to Figure 7 , shown as Figure 5 the front view schematic diagram of the structure shown, the distance ([ Figure 7 shown as d in [ is less than or equal to one-tenth of the diameter of the detection beam spot (within 10 μm). It should be noted that since the detection beam 113 has a columnar morphology, the distance between the two is the distance between the lowest point of the detection beam 113 in the vertical direction and the highest point of the upper surface 21 of the wafer carrier 20 (which can be regarded as the minimum distance between the two). After actual verification, it is found that when the level of the wafer carrier 20 deviates from the ideal level (that is, the upper surface 21 of the wafer carrier 20 is a standard horizontal plane) within the above range, the influence on the heating uniformity of the wafer 30 is within the process error allowable range. At this time, the wafer carrier 20 can continue to be used directly without calibration.

[0050] For example, refer to Figure 8 and Figure 9 , Figure 8 which shows a schematic diagram of the overall structure when the detection device includes a plurality of detection components, Figure 9 shown as Figure 8 a top view schematic diagram of the detection device shown in Figure 9 wherein the detection device 10 includes a plurality of the detection components 11, and a preset angle ( Figure 9 shown as θ in Figure 9 ) is formed between the setting directions of two adjacent detection components 11. The preset angle is set according to actual needs, and the detection components 11 are arranged at equal or unequal intervals, preferably the former. More preferably, each detection element divides the horizontal plane where the detection device 10 is located into equal parts (i.e., 2n equal parts, n≥1), and the flatness detection of each area of the wafer carrier 20 can be realized. Specifically, when the detection device 10 includes a plurality of detection components 11, the detection efficiency and convenience can be effectively improved. In addition, when the detection device 10 includes a plurality of detection components 11, the switches of the laser emitting element 111 and the laser receiving element 112 in each detection component 11 can be independently turned on / off, realizing flexible application.

[0051] In a specific example, as Figure 8 and Figure 9 shown, the detection device 10 includes four of the detection components 11, and a 45° angle is formed between the setting directions of two adjacent detection components 11. After actual verification, it is found that when the number of detection components 11 is 4, the overall cost and detection efficiency of the detection device 10 are both relatively appropriate, and the all-round flatness detection of the wafer carrier 20 can be basically realized.

[0052] As an example, the projection of the detection beam 113 on the upper surface 21 of the wafer carrier 20 passes through the center of the upper surface 21 of the wafer carrier 20, and more preferably, the laser emitting element 111 and the laser receiving element 112 in the same detection component 11 are axisymmetric about the vertical center axis of the wafer carrier 20, so that the edge ring is located at the center position of the area formed by the detection device 10, improving the detection convenience.

[0053] As an example, the wafer carrier 20 is disposed in a semiconductor machine tool, and the semiconductor machine tool includes a heat treatment machine tool.

[0054] In summary, the detection device suitable for detecting the levelness of a wafer carrier of the present utility model includes at least one detection component. The detection component includes a laser emitting element and a laser receiving element that are arranged on both sides of the wafer carrier and face each other. Whether the laser receiving element can receive the detection beam emitted by the laser emitting element can quickly and conveniently measure whether the levelness of the wafer carrier meets the requirements, effectively improving the efficiency of detecting and calibrating the levelness of the wafer carrier. In addition, by providing a carrying component, multiple groups of detection components, and / or rotatably arranging the detection device and the wafer carrier, the detection efficiency can be further improved. Therefore, the present utility model effectively overcomes various drawbacks in the prior art and has high industrial utilization value.

[0055] The above embodiments are only illustrative of the principles and effects of the present utility model and are not intended to limit the present utility model. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present utility model. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present utility model should still be covered by the claims of the present utility model.

Claims

1. A detection device suitable for detecting the levelness of a wafer carrier, characterized in that: The detection device is arranged on the periphery of the wafer carrier in the horizontal direction to detect the horizontality of the wafer carrier. The detection device includes at least one detection component, and the detection component includes a laser emitting element and a laser receiving element which are arranged on both sides of the wafer carrier and facing each other. The detection light beam emitted by the laser emitting element propagates in the horizontal direction above the wafer carrier.

2. The detection device for detecting the levelness of a wafer carrier according to claim 1, characterized in that: The detection device comprises a plurality of the detection components, and the arrangement directions of two adjacent detection components form a preset angle.

3. The detection device for detecting the levelness of a wafer carrier according to claim 2, characterized in that: The detection device comprises four detection components, and the setting directions of two adjacent detection components are 45 degrees apart.

4. The detection device for detecting the levelness of a wafer carrier according to claim 1, characterized in that: The detection device further comprises a bearing assembly, and the laser emitting element and the laser receiving element are both arranged on the bearing assembly.

5. The detection device for detecting the levelness of a wafer carrier according to claim 1, characterized in that: The wafer carrier comprises an edge ring, and the edge ring is provided with a carrying groove which vertically penetrates the edge ring to carry the wafer.

6. The detection device for detecting the levelness of a wafer carrier according to claim 5, characterized in that: The laser emitting element and the laser receiving element in the same detection component are symmetrical about the vertical center axis of the edge ring.

7. The detection device for detecting the levelness of a wafer carrier according to claim 1, characterized in that: The detection device is rotatably arranged relative to the wafer carrier.

8. The detection device for detecting the levelness of a wafer carrier according to claim 1, characterized in that: The distance between the propagation path of the detection beam and the upper surface of the wafer carrier is less than or equal to one tenth of the diameter of the detection beam spot.

9. The detection device for detecting the levelness of a wafer carrier according to claim 1, characterized in that: The laser emitting element includes at least one of a semiconductor laser and a microcavity laser, and the diameter of the detection light beam is in the micrometer order.

10. The detection device for detecting the levelness of a wafer carrier according to claim 1, characterized in that: The wafer carrier is disposed in a semiconductor machine, and the semiconductor machine includes a heat treatment machine.

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