Level calibration device

Abstract

The utility model relates to the technical field of semiconductors, and provides a horizontal calibration device which comprises a detection frame and a distance measurement unit, the distance measuring unit is arranged on the detection frame in a manner of rotating around a reference line; the detection frame comprises a plurality of detection reference surfaces, the detection frame is provided with a light-transmitting area, and the detection reference surfaces are arranged in the circumferential direction of the reference line; the distance measuring unit is located on one side of the detection reference surface in the direction of the reference line, and the distance measuring unit passes through the detection reference surfaces and the light-transmitting area when rotating around the reference line. According to the configuration, the distance measuring unit of the horizontal calibration device adopts non-contact measurement, the levelness of the transmission device can be calculated through multiple groups of relative distances, measurement errors caused by position changes of the distance measuring unit in the rotating process can be eliminated through relative distance measurement, and the measurement precision can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, in particular to a level calibration device. Background Art

[0002] The epitaxial growth process is an essential step in wafer processing. It uses the principle of nucleation due to two-dimensional structural similarity on the crystal interface to grow another single crystal layer with a complete lattice and different impurity concentrations and thicknesses along the original crystal axis on a single crystal wafer.

[0003] In the epitaxial growth process, the wafer needs to be transferred to the epitaxial furnace through a transfer device. The horizontality of the transfer device affects the position of the wafer, which in turn affects the epitaxial growth effect. The horizontal calibration of the current epitaxial furnace transfer device usually uses a traditional bubble level. The horizontality of the transfer device is judged by visually observing the position of the bubble in the level, and the level adjustment of the robot arm is performed based on the visual results.

[0004] During the calibration process of the above calibration method, the level needs to be placed on the transmission device. On the one hand, the weight of the level itself will affect the levelness of the transmission device and affect the calibration result. On the other hand, when the visual method is used for calibration, the calibration methods of each tester are inconsistent, the measurement results cannot be standardized, the measurement results vary greatly, and the horizontal calibration accuracy is low. Utility Model Content

[0005] The utility model provides a horizontal calibration device, which adopts a non-contact method to perform calibration and is beneficial to measurement standardization and improves calibration accuracy.

[0006] The horizontal calibration device comprises: a detection frame and a distance measuring unit;

[0007] The distance measuring unit is arranged on the detection frame so as to rotate around the reference line;

[0008] The detection frame includes a plurality of detection reference surfaces, the detection frame has a light-transmitting area, and each of the detection reference surfaces is arranged circumferentially around the reference line;

[0009] The distance measuring unit is located on one side of the detection reference surface along the direction of the reference line. When the distance measuring unit rotates around the reference line, it passes through each of the detection reference surfaces and the light-transmitting area.

[0010] Optionally, the detection frame further comprises a reference seat, a light-transmitting hole is formed on the reference seat, the area where the light-transmitting hole is located serves as the light-transmitting area, and the detection reference surface is arranged on the reference seat.

[0011] Optionally, the detection frame further comprises a plurality of reference plates, wherein the reference plates are attached to the reference base, and a side of the reference plates opposite to the reference base serves as the detection reference surface.

[0012] Optionally, the detection reference planes are coplanar, and the reference line is perpendicular to the detection reference planes.

[0013] Optionally, the detection frame further includes a mounting seat, the distance measuring unit is rotatably mounted on the mounting seat, and the reference seat is arranged on the mounting seat.

[0014] Optionally, there is a set distance between the reference seat and the mounting seat, and the reference seat and the mounting seat are connected via a connecting piece.

[0015] Optionally, the reference seat and the ranging unit are respectively arranged on both sides of the mounting seat along the direction of the reference line, and a plurality of through holes are opened on the mounting seat, each of the through holes corresponds to each of the detection reference surfaces one by one, and at least a portion of the through holes is arranged opposite to the detection reference surface along the direction of the reference line, and at least a portion of the through holes is arranged opposite to the light-transmitting area along the direction of the reference line.

[0016] Optionally, the mounting seat and / or the reference seat is in a plate-like structure; when both the mounting seat and the reference seat are in a plate-like structure, the mounting seat and the reference seat are arranged in parallel.

[0017] Optionally, the mounting seat and the reference seat are both circular and coaxially arranged, and the reference line is colinear with the central axis of the mounting seat.

[0018] Optionally, the distance measuring unit is a laser rangefinder.

[0019] In summary, the horizontal calibration device in the utility model includes: a detection frame and a distance measuring unit; the distance measuring unit is arranged on the detection frame to rotate around a reference line; the detection frame includes a plurality of detection reference surfaces, the detection frame has a light-transmitting area, and each of the detection reference surfaces is circumferentially arranged around the reference line; the distance measuring unit is located on one side of the detection reference surface along the direction of the reference line, and when the distance measuring unit rotates around the reference line, it passes through each of the detection reference surfaces and the light-transmitting area.

[0020] With such configuration, the above-mentioned horizontal calibration device should keep each detection reference surface level during calibration. The transmission device of the epitaxial growth equipment carries the wafer to the side of the horizontal calibration device along the direction of the reference line, and the distance measuring unit passes over each detection reference surface in turn during rotation. The laser emitted by the distance measuring unit is irradiated on the detection reference surface to measure the first distance from the detection reference surface. The laser can also pass through the light-transmitting area to irradiate the surface of the wafer to measure the second distance from the surface of the wafer. The relative distance between the upper surface of the wafer and the detection reference surface can be calculated by the difference between the above-mentioned second distance and the first distance. As the distance measuring unit rotates and passes over each detection reference surface in turn, multiple sets of relative distances can be measured. The horizontality of the transmission device can be calculated through multiple sets of relative distances, thereby achieving the purpose of horizontal calibration.

[0021] The above device can eliminate the measurement error caused by the change of the distance measuring unit's own position during the rotation process by comparing the relative distance between the detection reference surface and the wafer, which is beneficial to improve the measurement accuracy. At the same time, it can also simulate the normal film transmission environment, and the measured data and the calibration of the transmission device level and position are more accurate. The distance measuring unit adopts non-contact measurement, eliminating the influence of the measuring tool's own weight on the horizontality of the transmission device in the traditional contact measurement method, improving the measurement accuracy, and the measurement method has good consistency, the measurement results can be standardized, and the horizontal calibration accuracy is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the top view of the horizontal calibration device of some embodiments of the utility model;

[0023] Figure 2 It is a schematic cross-sectional structural diagram of a horizontal calibration device in some embodiments of the utility model.

[0024] The reference numerals are as follows:

[0025] 10-detection frame; 101-detection reference surface; 102-light-transmitting area; 11-mounting seat; 111-through hole; 12-reference seat; 121-light-transmitting hole; 13-reference sheet; 14-connecting piece;

[0026] 20- ranging unit;

[0027] 30-bearing;

[0028] 40- rotating rod;

[0029] 50- control unit;

[0030] 60-wafer;

[0031] a-Baseline. DETAILED DESCRIPTION

[0032] The horizontal calibration device proposed by the utility model is further described in detail below in combination with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the utility model will become clearer. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the utility model.

[0033] In the present utility model, "outer diameter" and "inner diameter" for circular structures correspond to diameter dimensions, and for non-circular structures, the inner diameter refers to the diameter of its inscribed circle, and the outer diameter refers to the diameter of its circumscribed circle; "axial direction" for a cylindrical rod body corresponds to the direction in which the axis thereof is located, and for a non-cylindrical rod body, the axial direction corresponds to the length direction of the rod body.

[0034] As used in the present invention, the singular forms "one", "a", and "the" include plural objects, the term "or" is usually used to include the meaning of "and / or", the term "several" is usually used to include the meaning of "at least one", and the term "at least two" is usually used to include the meaning of "two or more". In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", and "third" can explicitly or implicitly include one or at least two of the features. In addition, as used in the present invention, "installed", "connected", "connected", and one element "set" on another element should be understood in a broad sense, usually only indicating that there is a connection, coupling, matching or transmission relationship between the two elements, and the connection, coupling, matching or transmission between the two elements can be direct or indirect through an intermediate element, and cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, one element can be in any orientation such as inside, outside, above, below or on one side of another element, unless the content clearly indicates otherwise. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. In addition, directional terms such as above, below, up, down, upward, downward, left, right, etc. are used relative to the exemplary embodiments as they are shown in the figures, with the upward or upper direction toward the top of the corresponding figure, and the downward or lower direction toward the bottom of the corresponding figure.

[0035] This embodiment provides a horizontal calibration device, which includes a detection frame 10 and a distance measurement unit 20 .

[0036] like Figure 1 and Figure 2 As shown, the detection frame 10 further includes a mounting seat 11 , a reference seat 12 , a reference plate 13 and a connecting member 14 .

[0037] The mounting seat 11 is a plate-type structure and is in the shape of a disk, and the distance measuring unit 20 is arranged on the detection frame 10 to rotate around the reference line a, and the reference line a is colinear with the axis of the mounting seat 11. The distance measuring unit 20 and the control unit 50 can be connected wirelessly or wired, and the control unit 50 can be, for example, a control box provided by the rangefinder.

[0038] A mounting hole is provided at the center of the mounting seat 11, in which a bearing 30 is installed. The distance measuring unit 20 is installed on an "L"-shaped rotating rod 40. A right-angled side of the rotating rod 40 is inserted into the inner ring of the bearing 30 and rotates with the bearing 30. This side can be externally connected to a driving device to drive the rotating rod 40 to rotate around the reference line a; the other right-angled side of the rotating rod 40 is perpendicular to the reference line a and connected to the distance measuring unit 20. The length of the right-angled side is less than the radius of the mounting seat 11. The specific dimensions of each right-angled side of the rotating rod 40 can be adaptively adjusted based on actual usage requirements.

[0039] In this embodiment, the distance measuring unit 20 adopts a CMOS laser distance meter, such as a ZG2 laser distance meter, and the laser emitting end of the laser distance meter faces the reference seat 12. The use of a CMOS laser distance meter can digitize the measurement results, which is conducive to formulating standards for calibrating and adjusting the transmission device and facilitating regular calibration of the machine.

[0040] In other alternative embodiments, the distance measuring unit 20 may adopt an ultrasonic distance measuring device or other known non-contact distance measuring devices.

[0041] Please continue to refer to Figure 1 and Figure 2 As shown, in this embodiment, the reference seat 12 is in a circular ring structure, the reference seat 12 and the mounting seat 11 are coaxially arranged, and the outer periphery of the reference seat 12 is connected to the lower surface of the mounting seat 11 through a connecting member 14.

[0042] The connecting member 14 may be a plurality of connecting rods integrally formed with the reference seat 12, or the connecting member 14 may be a connecting sleeve integrally formed with the reference seat 12. In addition, the connecting member 14 may be provided separately from the reference seat 12, in which case the connecting member 14 may be connected to the mounting seat 11 and the reference seat 12 by bonding. The specific structure of the connecting member 14 and the connection method with the reference seat 12 and the mounting seat 11 may be adaptively adjusted based on actual use requirements.

[0043] In this embodiment, the mounting seat 11 and the reference seat 12 are arranged in parallel, and the mounting seat 11 and the reference seat 12 have a set distance along the direction of the reference line a. The setting of the set distance can facilitate the installation of the reference plate 13, and the specific size of the set distance can be adaptively adjusted based on actual usage requirements.

[0044] Please continue to refer to Figure 2As shown, the hollow position of the reference seat 12 is used as a light-transmitting hole 121, and the area where the light-transmitting hole 121 is located is used as the light-transmitting area 102. The reference sheet 13 is made of a non-transparent material, and the reference sheet 13 is pasted on the upper surface of the reference seat 12. The upper surface of the reference sheet 13 (the side of the reference sheet 13 opposite to the connecting member 14) is used as the detection reference surface 101. Therefore, the detection reference surface 101 is adjacent to the light-transmitting area in the radial direction.

[0045] In this embodiment, the reference sheet 13 is made of a silicon wafer, and the thickness of the silicon wafer is about 1 mm. In other alternative embodiments, the reference sheet 13 can also be made of other known non-transparent materials, and the material and thickness of the reference sheet 13 can be adaptively adjusted based on actual use requirements. In this embodiment, there is no special limitation on the pasting position of the reference sheet 13. For example, the reference sheet 13 can be conformally aligned with the inner circumference of the reference seat 12, conformally aligned with the outer circumference of the reference seat 12, or the reference sheet 13 can be pasted on the upper surface of the reference seat 12 between its inner circumference and outer circumference.

[0046] When the distance measuring unit 20 rotates to above the detection reference surface 101 , the laser emitted by the distance measuring unit 20 irradiates downward onto the detection reference surface 101 , and the distance to the detection reference surface 101 is measured.

[0047] Please continue to refer to Figure 1 and Figure 2 As shown, in this embodiment, four reference plates 13 are provided, and the reference plates 13 are in a fan-shaped shape, so the detection reference surface 101 is also in a fan-shaped shape, so that the measurement results are digitized and standardized, and the measurement data is more accurate. The four detection reference surfaces 101 are coplanar, and the reference line a is perpendicular to the detection reference surface 101. Each of the detection reference surfaces 101 is evenly arranged around the reference line a; when the distance measuring unit 20 rotates, it passes over the four reference plates 13 in sequence.

[0048] In this embodiment, the distance measuring unit 20 is located above the mounting seat 11 along the direction of the reference line a, and the reference seat 12 and the reference plate 13 are located below the mounting seat 11 along the direction of the reference line a. Four through holes 111 are opened on the mounting seat 11 along the direction of the reference line a, and each through hole 111 corresponds to each detection reference surface 101. The opening shape of the through hole 111 is fan-shaped, and the opening area of ​​the through hole 111 is larger than the area of ​​the detection reference surface 101. The opening area of ​​the through hole 111 here refers to the cross-sectional area of ​​the through hole 111 after cutting perpendicular to the reference line a.

[0049] like Figure 2 As shown, in this embodiment, a portion of the through hole 111 and the corresponding detection reference surface are along the direction where the reference line a is located ( Figure 2The other part of the through hole is opposite to the light-transmitting area 102 along the direction where the reference line a is located ( Figure 2 The upper and lower directions) are facing each other.

[0050] The through hole 111 is arranged so that the laser emitted during the rotation of the ranging unit 20 will irradiate downward through the through hole 111. In this embodiment, it is preferred that the ranging unit 20 emits a linear laser beam, a portion of the linear laser beam emitted downward by the ranging unit 20 is directly facing the reference surface 101, and this portion of the laser is irradiated on the reference surface 101, and another portion of the laser is directly facing the light-transmitting area 10, and this portion of the laser passes downward through the light-transmitting area 10.

[0051] In this embodiment, four reference plates 13 and four through holes 111 are provided. In other alternative embodiments, the number of reference plates 13 and four through holes 111 can be two, three or more. In this embodiment, the reference plates 13 and four through holes 111 are both in the shape of a fan ring. In other alternative embodiments, the shapes of the reference plates 13 and four through holes 111 can be circular, rectangular or other shapes.

[0052] In this embodiment, the detection reference surface 101 is formed by a reference sheet 13 attached to the reference seat 12. In other alternative embodiments, the detection reference surface 101 can be formed by coating or painting the reference seat 12. The formation method of the detection reference surface 101 can be adaptively adjusted based on actual use requirements.

[0053] In this embodiment, the mounting seat 11 and the reference seat 12 are both circular. In other alternative embodiments, the shapes of the mounting seat 11 and the reference seat 12 can be square or other shapes, and the shapes of the mounting seat 11 and the reference seat 12 can be adaptively adjusted based on actual practical needs.

[0054] In this embodiment, the mounting seat 11 and the reference seat 12 are split structures. In other alternative embodiments, the mounting seat 11 and the reference seat 12 can be an integrated structure. Or the mounting seat 11, the reference seat 12 and the connecting member 14 can be an integrated structure.

[0055] In this embodiment, in order to reduce the weight of the entire horizontal calibration device, the material of the mounting seat 11 and the reference seat 12 can be an acrylic plate, the connecting member 14 can be an acrylic rod, and the rotating rod 40 can be an acrylic rod. In other alternative embodiments, the material of each component of the horizontal calibration device can be adaptively selected based on the use requirements such as structural strength and density.

[0056] The above-mentioned level calibration device should keep each detection reference surface 101 level during calibration. The transmission device of the epitaxial growth equipment carries the wafer 60 and moves to Figure 2In the lower part of the horizontal calibration device, the distance measuring unit 20 passes through each through hole 111 and the detection reference surface 101 in turn during the rotation process. A part of the laser beam emitted by the distance measuring unit 20 passes through the through hole 111 and irradiates the detection reference surface 101 to measure the first distance from the detection reference surface 101. Another part of the laser beam emitted by the distance measuring unit 20 passes through the through hole 111 and then passes downward through the light-transmitting area 102 to irradiate the surface of the wafer 60 to measure the second distance from the surface of the wafer 60. The relative distance between the upper surface of the wafer 60 and the detection reference surface 101 can be calculated by the difference between the above-mentioned second distance and the first distance. As the distance measuring unit 20 rotates and passes over each detection reference surface 101 in turn, multiple groups of relative distances can be measured, and the horizontality of the transmission device can be calculated by the multiple groups of relative distances, thereby achieving the purpose of horizontal calibration.

[0057] The above device can eliminate the measurement error caused by the position change of the distance measuring unit 20 during the rotation process by comparing the relative distance between the detection reference surface 101 and the wafer 60, which is beneficial to improve the measurement accuracy. At the same time, it can also simulate the normal film transmission environment, and the measured data and the calibration transmission device level and position are more accurate. The distance measuring unit 20 adopts non-contact measurement, eliminating the influence of the weight of the measuring tool itself on the levelness of the transmission device in the traditional contact measurement method, improving the measurement accuracy, and the measurement method has good consistency, the measurement results can be standardized, and the level calibration accuracy is high.

[0058] When using the device, placing it in the load lock position can calibrate the level and position of the robotic arms of the two transmission devices before and after the epitaxial growth equipment at the transmission end point, which helps to calibrate the robotic arms of all transmission devices covering the epitaxial growth equipment.

[0059] In this embodiment, the ranging unit 20 emits a linear laser beam. In other alternative embodiments, the ranging unit 20 can also be configured to emit two point laser beams, one laser beam is used to irradiate the detection reference surface 101, and the other laser beam is used to irradiate the upper surface of the wafer 60.

[0060] In this embodiment, the connecting member 14 is connected to the upper surface of the reference seat 12 and close to its outer peripheral surface. In other alternative embodiments, the connecting member 14 can be connected to the middle position of the upper surface of the reference seat 12 or close to its inner peripheral surface. In addition, in order to avoid interference between the connecting member 14 and the reference sheet 13, the connecting member 14 and the reference sheet 13 are staggered along the circumferential direction of the reference seat 12.

[0061] In this embodiment, the light-transmitting area 102 is formed by a light-transmitting hole 121 opened in the middle of the reference seat 12, and this arrangement makes the reference seat 12 as a whole annular. In other alternative embodiments, the light-transmitting area 102 can also be formed by a plurality of openings, and each opening is alternately arranged with each reference sheet 13 along the circumferential direction of the reference seat 12. In this case, the distance measuring unit 20 passes through the reference sheet 13 and the opening alternately in sequence during the rotation process. The light-transmitting area 102 can also be arranged in other feasible ways, which will not be described one by one here.

[0062] The above description is only a description of the preferred embodiment of the utility model, and is not any limitation to the scope of the utility model. Any changes and modifications made by ordinary technicians in the field of the utility model based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A level calibration device, characterized in that: include: Detection frame and distance measuring unit; The distance measuring unit is arranged on the detection frame so as to rotate around the reference line; The detection frame includes a plurality of detection reference surfaces, the detection frame has a light-transmitting area, and each of the detection reference surfaces is arranged circumferentially around the reference line; The distance measuring unit is located on one side of the detection reference surface along the direction of the reference line. When the distance measuring unit rotates around the reference line, it passes through each of the detection reference surfaces and the light-transmitting area.

2. The horizontal calibration device according to claim 1, characterized in that: The detection frame also includes a reference seat, a light-transmitting hole is opened on the reference seat, the area where the light-transmitting hole is located is used as the light-transmitting area, and the detection reference surface is arranged on the reference seat.

3. The horizontal calibration device according to claim 2, characterized in that: The detection frame also includes a plurality of reference plates, which are attached to the reference seat, and the side of the reference plate opposite to the reference seat serves as the detection reference surface.

4. The level calibration device according to any one of claims 1 to 3, characterized in that: The detection reference surfaces are coplanar, and the reference line is perpendicular to the detection reference surfaces.

5. The horizontal calibration device according to claim 2, characterized in that: The detection frame also includes a mounting seat, the distance measuring unit is rotatably mounted on the mounting seat, and the reference seat is arranged on the mounting seat.

6. The level calibration device according to claim 5, characterized in that: There is a set distance between the reference seat and the mounting seat, and the reference seat is connected to the mounting seat via a connecting piece.

7. The level calibration device according to claim 5, characterized in that: The reference seat and the distance measuring unit are respectively arranged on both sides of the mounting seat along the direction of the reference line. The mounting seat is provided with a plurality of through holes, each of the through holes corresponds to each of the detection reference surfaces one by one, at least a portion of the through holes is arranged opposite to the detection reference surface along the direction of the reference line, and at least a portion of the through holes is arranged opposite to the light-transmitting area along the direction of the reference line.

8. The level calibration device according to claim 6, characterized in that: The mounting seat and / or the reference seat are in a plate-like structure; when both the mounting seat and the reference seat are in a plate-like structure, the mounting seat and the reference seat are arranged in parallel.

9. The horizontal calibration device according to claim 6, characterized in that: The mounting seat and the reference seat are both circular and coaxially arranged, and the reference line is colinear with the central axis of the mounting seat.

10. The level calibration device according to claim 1, characterized in that: The distance measuring unit is a laser distance meter.

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