A laser interferometry detection device for wafer etching endpoints

Abstract

This invention discloses a laser interferometric detection device for the end point of wafer etching, comprising a support device for supporting the wafer; a detection unit, spaced apart from the support device, for emitting detection light, which is focused onto a detection area on the surface of the wafer to detect the end point position of the wafer etching; and a driving unit comprising a driving part and an adjusting part, one end of the adjusting part being connected to the driving part and the other end being connected to the detection unit; the driving part driving the adjusting part and the detection unit to move along the X or Y direction; and the adjusting part comprising a movable first adjusting member, which is placed at the bottom of the detection unit and pushes the detection unit to move during movement to adjust the deflection angle of the detection unit. This invention can adjust the detection unit when the detection unit deflects at an angle, so that the light emitted by the detection unit illuminates a preset position.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a laser interferometry detection device for the end point of wafer etching. Background Technology

[0002] A wafer may have multiple different functional regions, each with different etching requirements. For example, in integrated circuit manufacturing, a wafer may have transistor regions, interconnect regions, isolation regions, etc., and the location of the area to be inspected is different in each region.

[0003] In semiconductor etching processes, laser interferometry (LIFT) is a high-precision technology used to monitor the etching process. Its principle involves irradiating the wafer surface with a highly monochromatic laser beam at a specific angle. The laser penetrates the transparent or semi-transparent film to be etched (such as polysilicon, silicon dioxide, or photoresist) and is reflected from both the upper and lower surfaces of the film. These two reflected beams interfere due to the optical path difference, and after being received by a photodetector, they form a sinusoidal interference signal that varies with time. However, this detection method places extremely stringent requirements on the precision of the optical path. Its limitation lies in the fact that the LIFT unit is typically integrated outside the etching chamber, and the laser must pass through a sealed optical viewport to enter the wafer inside the chamber. To ensure the interference effect, the incident and receiving optical paths must maintain a high degree of collimation and stability. Vibrations during long-term operation, thermal expansion due to chamber heating / cooling, or mechanical stress causing the detection unit to tilt can lead to various problems during the interferometry process. For example, if the incident light path deviates, the laser spot may deviate from the predetermined wafer measurement area, or even irradiate a patterned area with a complex topology, resulting in a sharp decrease in the contrast of the interference signal and a reduction in the signal-to-noise ratio. Alternatively, if the receiving light path is misaligned, the interference light reflected from the wafer surface may not be accurately coupled back to the receiving fiber or the sensitive area of ​​the detector, causing severe attenuation of the light intensity, or even complete loss of the signal. Or, if the interference conditions are disrupted, a small change in angle may alter the effective optical path of the laser within the thin film, introducing unpredictable phase errors, leading to distortion of the calculated thin film thickness. Ultimately, this may prevent the accurate capture of the last interference cycle marking the completion of etching, resulting in a misjudgment of the etching endpoint.

[0004] Therefore, it is necessary to provide a new laser interferometry detection device for wafer etching endpoints to solve the above-mentioned problems in the prior art. Summary of the Invention

[0005] The technical problem to be solved by this application is how to provide a laser interferometric detection device for the end point of wafer etching, so as to adjust the detection unit when the angle of the detection unit is deflected, so that the light emitted by the detection unit can illuminate the preset position.

[0006] To address the aforementioned technical problems, according to embodiments of this application, a laser interferometry detection device for the end point of wafer etching is provided, comprising:

[0007] A carrier device used to support wafers;

[0008] The detection unit, spaced apart from the carrier device, is used to emit detection light rays, which are focused onto the area to be detected on the surface of the wafer to detect the etching endpoint position of the wafer.

[0009] A driving unit includes a driving part and an adjusting part. One end of the adjusting part is connected to the driving part, and the other end is used to connect to the detection unit. The driving part is used to drive the adjusting part and the detection unit to move along the X direction or the Y direction. The adjusting part includes a movable first adjusting member, which is placed at the bottom of the detection unit and pushes the detection unit to move during the movement to adjust the deflection angle of the detection unit.

[0010] According to an embodiment of this application, the adjustment unit further includes an adjustment platform, a driving component, and a control component;

[0011] The top surface of the adjustment platform is used to mount the detection unit, and the bottom surface of the detection unit is attached to the top surface of the adjustment platform; the adjustment platform has an adjustment cavity; the top surface of the adjustment platform has a plurality of adjustment holes communicating with the adjustment cavity; the plurality of adjustment holes are evenly distributed along the X and Y directions;

[0012] One end of the first adjusting member is disposed in the adjusting hole, and the other end is movably disposed in the bottom wall of the adjusting cavity; the driving member is disposed in the side wall of the first adjusting member;

[0013] The control component is located inside the adjustment cavity and is used to drive the moving member to move so that the end of the first adjusting member protrudes from the adjustment hole and pushes the detection unit to move, thereby adjusting the deflection angle of the detection unit.

[0014] According to an embodiment of this application, the adjusting part further includes a second adjusting member; the second adjusting member is disposed on the inner wall of the adjusting hole, and the second adjusting member is made of a flexible material; one end of the first adjusting member is disposed on the end face of the second adjusting member.

[0015] According to an embodiment of this application, the thickness of the second adjusting member is greater than or equal to 4 mm.

[0016] According to an embodiment of this application, the bottom of the adjustment cavity is provided with a plurality of sliding grooves, each of the sliding grooves corresponding to an adjustment hole; the other end of the second adjustment member is movably disposed in the sliding groove.

[0017] According to an embodiment of this application, the bottom of the first adjusting member is flat, so that when the first adjusting member is vertically arranged, the bottom of the first adjusting member is in contact with the bottom wall of the sliding groove.

[0018] According to an embodiment of this application, the control assembly includes a control rod, a control element, and a pusher; the control rod is disposed within the adjustment cavity; the control element is movably disposed on the control rod; a first control groove is formed on the side wall of the control element, and a second control groove is formed on the top wall of the first control groove; the pusher is movably disposed on the second control groove.

[0019] During the movement of the control component, the pusher contacts the drive component to push the drive component to move; when the drive component moves to its limit position, the drive component applies a force to the pusher component, causing the pusher component to move towards the bottom wall of the second control groove.

[0020] According to an embodiment of this application, the pusher has symmetrically arranged push surfaces, each push surface including a first contact segment and a second contact segment; the angle between the first contact segment and the top wall of the first control groove is greater than 45°; the angle between the second contact segment and the top wall of the first control groove is less than 45°.

[0021] According to an embodiment of this application, the top surface of the adjustment platform is provided with a plurality of stabilizing holes; the adjustment part further includes an elastic member, one end of which is disposed on the bottom wall of the stabilizing hole and the other end of which is disposed on the bottom wall of the detection unit, so as to apply a force to the detection unit to move toward the adjustment part.

[0022] According to an embodiment of this application, the driving part includes a mounting body, a first driving member, a second driving member, and a connecting part; the mounting body has a mounting cavity; the connecting part is disposed in the mounting cavity and is used to connect with the adjusting part; the first driving member extends along the X direction and is movably disposed in the mounting cavity along the Y direction; the second driving member extends along the Y direction and is movably disposed in the mounting cavity along the X direction; both the first driving member and the second driving member pass through the connecting part; the first driving member and the second driving member cooperate to adjust the position of the connecting part.

[0023] Beneficial effects: By adopting the above technical solution, the driving unit controls the adjustment unit and the detection unit to move in the X or Y direction, thereby focusing the light emitted by the detection unit onto the detection area on the wafer surface; when the light emitted by the detection unit is not focused onto the detection area on the wafer surface and the camera cannot receive the light emitted by the wafer; or when the light emitted by the detection unit is focused onto the detection area on the wafer surface and the camera cannot receive the light emitted by the wafer; it indicates that the detection unit is deflected. At this time, by controlling the first adjustment member at different positions in the adjustment unit, the deflection angle of the detection unit is adjusted, so that the light emitted by the detection unit is focused onto the detection area on the wafer surface. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the main structure of a laser interferometry detection device according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the adjustment section of a laser interferometry detection device according to an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram showing the position of the stabilizing hole in the adjustment section of a laser interferometry detection device according to an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the structure of the second adjusting member protruding according to an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the structure when the pushing member and the driving member are in contact according to an embodiment of the present invention;

[0029] Figure 6 This is a schematic diagram of the positional relationship when the driving component applies a reverse force to the pushing component according to an embodiment of the present invention;

[0030] Figure 7 This is a schematic diagram of the force analysis when the driving component comes into contact with the first contact segment according to an embodiment of the present invention;

[0031] Figure 8 This is a schematic diagram of the force analysis when the driving component comes into contact with the second contact segment according to an embodiment of the present invention;

[0032] Figure 9 This is a schematic diagram of the internal structure of a drive unit according to an embodiment of the present invention;

[0033] Figure 10 This is a schematic diagram illustrating the positional relationship when the detection unit angle is deflected according to an embodiment of the present invention, and the camera cannot receive the light reflected from the wafer.

[0034] Figure 11This is a schematic diagram of the positional relationship when the detection unit angle is not deflected and the camera can receive the light reflected from the wafer, according to an embodiment of the present invention.

[0035] Figure label:

[0036] 100. Bearing device; 200. Detection unit; 300. Drive unit; 400. Drive section; 410. Mounting body; 420. First drive component; 430. Second drive component; 440. Connecting part; 500. Adjustment section; 510. First adjustment component; 520. Adjustment platform; 521. Adjustment cavity; 522. Adjustment hole; 523. Sliding groove; 524. Stabilizing hole; 525. Elastic component; 530. Driving component; 540. Second adjustment component; 550. Control rod; 560. Control component; 561. First control groove; 562. Second control groove; 563. Elastic component; 570. Pushing component; 571. Pushing surface; 572. First contact section; 573. Second contact section; 610. First horizontal force; 620. First vertical force; 630. Second horizontal force; 640. Second vertical force. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but does not exclude other elements or objects.

[0038] The following is combined Figures 1-11 The specific embodiments of the present invention will be further described in detail below.

[0039] Embodiments of the present invention provide a laser interferometry detection device for the end point of wafer etching, comprising:

[0040] The carrier device 100 is used to carry the wafer;

[0041] The detection unit 200 is spaced apart from the carrier device 100 and is used to emit detection light. The detection light is focused onto the area to be detected on the surface of the wafer to detect the etching endpoint position of the wafer.

[0042] The drive unit 300 includes a drive section 400 and an adjustment section 500. One end of the adjustment section 500 is connected to the drive section 400, and the other end is used to connect to the detection unit 200. The drive section 400 is used to drive the adjustment section 500 and the detection unit 200 to move along the X or Y direction. The adjustment section 500 includes a movable first adjustment member 510, which is placed at the bottom of the detection unit 200 and pushes the detection unit 200 to move during the movement, so as to adjust the deflection angle of the detection unit 200.

[0043] In some embodiments, the support device 100 is an etching chamber, and an electrostatic chuck is provided inside the etching chamber to support and fix the wafer, thereby fixing the wafer inside the etching chamber. The top of the etching chamber has a window so that the light emitted by the detection unit 200 can pass through the window and illuminate the surface of the wafer, thereby detecting the wafer. Specifically, the etching chamber and the electrostatic chuck are existing technologies and will not be described in detail here.

[0044] In some embodiments, to facilitate detection by the detection unit 200, a gap is provided between the detection unit 200 and the support device 100; and the detection unit 200 has a housing and a detection unit 200, wherein the detection unit 200 is disposed inside the housing; the detection unit 200 has a lens group, a camera and a light source, the light emitted by the light source is focused onto the area to be detected on the wafer surface after passing through the lens group, and after being reflected by the area to be detected, it passes through the lens group again and is received by the camera, which is prior art and will not be described in detail here. The housing is used to connect the detection unit 200 to the driving unit 300 so that the driving unit 300 can drive the position of the detection unit 200 to change, thereby enabling the light emitted by the detection unit 200 to be focused onto the area to be detected on the wafer surface.

[0045] In some embodiments, to facilitate control of the movement of the detection unit 200, the drive unit 300 includes a drive section 400 and an adjustment section 500; wherein, both the drive section 400 and the adjustment section 500 are disposed at the bottom of the detection unit 200; specifically, the adjustment section 500 is disposed between the detection unit 200 and the drive section 400, and one end of the adjustment section 500 is connected to the drive section 400, and the other end is connected to the detection unit 200; the drive section 400 can drive the adjustment section 500 and the detection unit 200 to move synchronously along the X direction or along the Y direction, so that the detection unit 200 can move synchronously. The focusing position of the light emitted by unit 200 is moved to the area to be detected for detection. The adjustment unit 500 includes a movable first adjustment member 510. Specifically, the first adjustment member 510 can push the detection unit 200 to move vertically during the movement, thereby adjusting the angle of the detection unit 200. For example, the first adjustment member 510 can push one edge of the bottom of the detection unit 200 during the movement, thereby tilting the position of the detection unit 200 to adjust the focusing position of the light emitted by the detection unit 200. Specifically, since the light emitted by the detection unit 200 needs to be reflected by the wafer and then pass through the lens group to illuminate the camera, if the detection unit 200 is tilted, the emitted light will also be tilted, causing the light reflected by the wafer to fail to illuminate the camera. At this time, the angle of the detection unit 200 can be finely adjusted by the adjustment unit 500 to adjust the position of the light emitted by the detection unit 200 so that the light emitted by the detection unit 200 can illuminate the camera after being reflected by the wafer.

[0046] In some specific embodiments, the deflection angle of the detection unit 200 is ±10° along the X direction and ±10° along the Y direction; the adjustment height of the adjustment unit 500 is adapted to the deflection angle of the detection unit 200.

[0047] In some embodiments, the adjustment unit 500 further includes an adjustment platform 520, a drive element 530, and a control component.

[0048] Specifically, the top surface of the adjustment platform 520 is used to install the detection unit 200; more specifically, the bottom surface of the detection unit 200 is attached to the top surface of the adjustment platform 520 to increase the contact area between the detection unit 200 and the adjustment platform and improve the stability of the detection unit 200.

[0049] In some specific embodiments, the adjustment platform 520 has an adjustment cavity 521, which is located inside the adjustment platform 520. Simultaneously, the top surface of the adjustment platform 520 has multiple adjustment holes 522 communicating with the adjustment cavity 521. Each communication hole penetrates the top surface of the adjustment platform 520 and communicates with the adjustment cavity 521. The multiple adjustment holes 522 are evenly distributed along the X and Y directions, forming a rectangle with equal spacing in the X and Y directions on the top surface of the adjustment platform 520. The structure within each adjustment hole 522 allows for adjustment of the detection unit 200.

[0050] In some embodiments, the X direction and the Y direction are perpendicular to each other; in this embodiment, the X direction is defined as the direction that is close to or far from the bearing unit on the horizontal plane, and the Y direction is the direction that is perpendicular to the X direction on the horizontal plane.

[0051] In some more specific embodiments, the first adjusting member 510 is inclined, with one end of the first adjusting member 510 located in the adjusting hole 522 and the other end movably located in the bottom wall of the adjusting cavity 521. In the initial state, the end of the first adjusting member 510 does not protrude from the adjusting hole 522, and the detection unit 200 is in contact with the adjusting part 500. When the first adjusting member 510 starts to move, that is, when the bottom of the first adjusting member 510 moves towards the adjusting hole 522 closer to itself in the bottom wall of the adjusting cavity 521, since the length of the first adjusting member 510 remains unchanged, the end of the first adjusting member 510 placed in the adjusting hole 522 will protrude from the adjusting hole 522, contact the detection unit 200, and push the detection unit 200 away from the adjusting part 500 in the vertical direction, causing the detection unit 200 to tilt, thereby adjusting the deflection angle of the light emitted by the detection unit 200. In addition, the drive member 530 is located on the side wall of the first adjusting member 510, and the movement of the first adjusting member 510 can be controlled by controlling the movement of the drive member 530.

[0052] In some more specific embodiments, the control component is located in the adjustment cavity 521 and is used to drive the drive member 530 to move, thereby driving the first adjustment member 510 to move, so that the end of the first adjustment member 510 protrudes from the adjustment hole 522 and pushes the detection unit 200 to move, thereby adjusting the deflection angle of the detection unit 200.

[0053] In some embodiments, to reduce the possibility of the end of the first adjusting member 510 disengaging from the adjusting hole 522 and entering the adjusting cavity 521, the adjusting part 500 further includes a second adjusting member 540. The second adjusting member 540 is disposed on the inner wall of the adjusting hole 522, and its placement method can be adhesive, snap-fit, or bolted, etc., without limitation, as long as the fixed position of the second adjusting member 540 within the adjusting hole 522 does not change. Furthermore, the second adjusting member 540 is made of a flexible material, allowing it to deform. One end of the first adjusting member 510 is disposed on the end face of the second adjusting member 540, and its placement method can be adhesive, snap-fit, or bolted, etc., without limitation, as long as the position of the first adjusting member 510 on the second adjusting member 540 does not move.

[0054] In some specific embodiments, the second adjusting member 540 can be made of rubber, silicone, or other elastic materials; the bottom of the second adjusting member 540 is integrally formed with a cylindrical connecting sleeve, the end of the first adjusting member 510 passes through the connecting sleeve and is interference-fitted with the connecting sleeve, thereby connecting the first adjusting member 510 and the second adjusting member 540; during the movement of the first adjusting member 510, the first adjusting member 510 and the second adjusting member 540 will not separate, so that each first adjusting member 510 can push the detection unit 200 to move at the corresponding position, thereby fine-tuning the detection unit 200.

[0055] In some embodiments, since the first adjusting member 510 is made of rigid material, contact between the first adjusting member 510 and the detection unit 200 may cause damage to the bottom of the detection unit 200. In order to reduce the damage to the bottom of the detection unit 200 caused by the first adjusting member 510, the thickness of the second adjusting member 540 is set to be greater than or equal to 4 mm. In some embodiments, the thickness of the second adjusting member 540 can be 5 mm, 6 mm, 7 mm or other thicknesses, so as not to interfere with the movement of the first adjusting member 510 and the first adjusting member 510 can push the second adjusting member 540 to protrude from the adjusting hole 522 to adjust the detection unit 200.

[0056] In some embodiments, since there are multiple first adjustment members 510, in order to make the control directions of the multiple first adjustment members 510 consistent, so as to facilitate the control of the multiple first adjustment members 510, multiple sliding grooves 523 are provided at the bottom of the adjustment cavity 521, and each sliding groove 523 corresponds to an adjustment hole 522; the other end of the second adjustment member 540 is movably disposed in the sliding groove 523. Specifically, taking the sliding groove 523 extending along the X direction as an example, the two ends of the sliding groove 523 in the length direction are defined as a reset end and a protruding end, respectively. When the end of the first adjusting member 510 contacts the reset end, the first adjusting member 510 is inclined in the adjusting cavity 521. At this time, the end of the first adjusting member 510 placed in the adjusting hole 522 will not protrude from the adjusting hole 522, that is, the second adjusting member 540 will not protrude from the adjusting hole 522 and contact the bottom of the detection unit 200. When the end of the first adjusting member 510 contacts the protruding end, the first adjusting member 510 is vertical in the adjusting cavity 521. At this time, the end of the first adjusting member 510 placed in the adjusting hole 522 protrudes from the adjusting hole 522, that is, the second adjusting member 540 protrudes from the adjusting hole 522 and contacts the bottom of the detection unit 200. More specifically, in order to increase the stability of the first adjusting member 510 when it is vertically set, the end face of the protruding end is set to be parallel to the side wall of the first adjusting member 510 when it is vertically set, so that the connecting sleeve and the protruding end together limit the first adjusting member 510.

[0057] In some specific embodiments, the bottom of the first adjusting member 510 is planar, so that when the first adjusting member 510 is vertically positioned, the bottom of the first adjusting member 510 is in contact with the bottom wall of the sliding groove 523; that is, when the bottom end of the first adjusting member 510 contacts the reset end, one edge of the bottom surface of the first adjusting member 510 contacts the bottom surface of the sliding groove 523, and the other end surface contacts the reset end; when the bottom end of the first adjusting member 510 contacts the protruding end, the bottom surface of the first adjusting member 510 contacts the bottom surface of the sliding groove 523, which increases the contact area between the bottom surface of the first adjusting member 510 and the bottom wall of the sliding groove 523 when the first adjusting member 510 is vertical, thereby improving the stability of the first adjusting member 510 in the vertical state.

[0058] In some embodiments, to facilitate control of the position of the first adjusting member 510, a control assembly is provided including a control rod 550, a control member 560, and a pusher 570. Specifically, the control rod 550 is disposed within the adjusting cavity 521, and the control member 560 is movably disposed on the control rod 550, allowing the control member 560 to move along the axial direction of the control rod 550. More specifically, the control rod 550 has a circular cross-section, and its axial direction is parallel to the X direction. The control member 560 has a control hole, through which the control rod 550 passes, and the control rod 550 is threadedly connected to the inner wall of the control hole. This allows the control member 560 to move along the axial direction of the control rod 550 when the control rod 550 rotates, contacting the first adjusting member 510 at different positions, thereby controlling the movement of the first adjusting member 510 at different positions to adjust the angle of the detection unit 200. Furthermore, in order to drive the control component 560 to move along the axial direction of the control rod 550 when the control rod 550 rotates, the bottom wall of the control component 560 is set to fit against the bottom wall of the adjustment cavity 521, so that the control rod 550 will not drive the control component 560 to rotate synchronously when it rotates.

[0059] In some embodiments, since the control member 560 needs to reciprocate on the control rod 550 to push the first adjusting member 510 between the reset end and the protruding end, the control member 560 needs to be able to contact the first adjusting member 510 from both the reset end and the protruding end. Therefore, a first control groove 561 is provided on the side wall of the control member 560, which extends through the control member 560 in the X direction, making the cross-section of the control member 560 C-shaped. A second control groove 562 is provided on the top wall of the first control groove 561. The pushing member 570 is movably disposed in the second control groove 562. An elastic member 563 is provided within the second control groove 562, with one end abutting against the bottom wall of the second control groove 562 and the other end abutting against the pushing member 570 to apply a force away from the second control groove 562 to the pushing member 570. In some specific embodiments, the elastic member 563 is a spring. Meanwhile, the pusher 570 will not disengage from the second control slot 562, which is existing technology and will not be described in detail here.

[0060] During the movement of the control member 560, the side wall of the push member 570 contacts the drive member 530 to push the drive member 530 to move; when the drive member 530 moves to its limit position, the drive member 530 applies a force to the push member 570, causing the push member 570 to move towards the bottom wall of the second control groove 562; taking the movement of the end of the first adjusting member 510 from the reset end to the protruding end as an example, the side wall of the push member 570 contacts the drive member 530 at the reset end, pushing the drive member 530 to move towards the protruding end until the first adjusting member 510 is vertically set, at which point the first adjusting member 510 is vertically set. When the side wall of component 510 is in contact with the protruding end, neither the first adjusting component 510 nor the driving component 530 can continue to move. The control component 560 continues to move on the control rod 550. At this time, the driving component 530 applies a force to the pushing component 570 to move towards the bottom of the second control groove 562 until the pushing component 570 disengages from the driving component 530. When the pushing component 570 controls the end of the first adjusting component 510 to move from the protruding end to the reset end, the other side wall of the pushing component 570 contacts the driving component 530. The way it pushes the driving component 530 to move is the opposite of the above, which will not be described in detail here.

[0061] In some embodiments, in order to facilitate the movement of the pusher 570 and the drive member 530, and at the same time, the drive member 530 can provide the pusher 570 with a reverse force at the protruding end or the reset end, the pusher 570 is provided with symmetrically arranged push surfaces 571, which are the two sidewalls of the pusher 570 opposite each other in the X direction. Specifically, the pushing surface 571 includes a first contact segment 572 and a second contact segment 573; the first contact segment 572 is located above the second contact segment 573, and there is a smooth transition between the first contact segment 572 and the second contact segment 573; the vertical height of the first contact segment 572 is greater than the diameter of the driving member 530, and the vertical height of the second contact segment 573 is greater than the diameter of the driving member 530; thereby adapting to the movement mode of the driving member 530 in the vertical direction caused by the end of the first adjusting member 510 during the movement; when the end of the first adjusting member 510 is at the protruding end, the first contact segment 572 of the pushing surface 571 contacts the driving member 530 first; when the end of the first adjusting member 510 is at the reset end, the first contact segment 572 of the pushing surface 571 contacts the driving member 530 first.

[0062] In some specific embodiments, the angle between the first contact segment 572 and the top wall of the first control groove 561 is greater than 45°; during the process of the pusher 570 pushing the drive member 530 to move, the reverse force applied by the drive member 530 to the pusher 570 is decomposed into a first horizontal force 610 in the horizontal direction and a first vertical force 620 in the vertical direction, and the force applied by the elastic member 563 to the pusher 570 is greater than the first vertical force 620, more specifically, the force applied by the elastic member 563 to the pusher 570 is 1.5 times the first vertical force 620; since the angle between the first contact segment 572 and the top wall of the first control groove 561 is greater than 45°, the pusher 570 in During the movement of the driving member 530, the first horizontal force 610 is greater than the first vertical force 620, thereby reducing the possibility that the driving member 570 may be unable to continue moving when it moves from the reset end to the protruding end or from the protruding end to the reset end. This ensures that the end of the first adjusting member 510 can move smoothly from the reset end to the protruding end or from the protruding end to the reset end. The angle between the second contact section 573 and the top wall of the first control groove 561 is less than 45°. Taking the example of the driving member 570 pushing the end of the first adjusting member 510 from the reset end to the protruding end, the first adjusting member 530 can continue moving when it moves into the second control groove 562. When component 510 is at its protruding end, it can no longer move, while control component 560 continues to move. At this time, push component 570 continues to apply force to drive component 530, causing the reverse force applied by drive component 530 to push component 570 to gradually increase until the first vertical force 620 exceeds the force applied by elastic component 563 to push component 570. At this time, push component 570 begins to move towards the bottom of the second control groove 562. As push component 570 moves, drive component 530 changes from contacting the first contact segment 572 to contacting the second contact segment 573. After drive component 530 contacts the second contact segment 573, the reverse force applied by drive component 530 to push component 570 decomposes into water. The second horizontal force 630 in the horizontal direction and the second vertical force 640 in the vertical direction are less than 45° because the angle between the second contact section 573 and the top wall of the first control groove 561 is less than 45°. Therefore, during the continued movement of the pushing member 570, the second horizontal force 630 is less than the second vertical force 640, thereby reducing the force exerted by the driving member 530 on the pushing member 570 in the horizontal direction. This facilitates the pushing member 570 to quickly detach from the driving member 530 it has been in contact with, so as to move to the next driving member 530. After the pushing member 570 separates from the driving member 530, the detection unit 200 is sufficiently stable because the first adjusting member 510 is vertically arranged and its bottom is planar. In some more specific embodiments, a motor is provided in the adjusting cavity 521, and the motor shaft is connected to the control rod 550 to drive the control rod 550 to rotate, thereby facilitating the control of the movement of the control member 560.

[0063] In some embodiments, since there are multiple first adjusting rods, it is necessary to ensure the stability of the detection unit 200 during the adjustment of its angle. Specifically, to ensure the stability of the detection unit 200, multiple stabilizing holes 524 are provided on the top surface of the adjusting platform 520; the stabilizing holes 524 extend toward the adjusting cavity 521 and are not connected to it; the adjusting part 500 also includes an elastic member 525, one end of which is disposed on the bottom wall of the stabilizing hole 524 and the other end of which is disposed on the bottom wall of the detection unit 200, so as to apply a force to the detection unit 200 to move toward the adjusting part 500. Specifically, the bottom of the housing of the detection unit 200 is provided with multiple connecting posts by means of integral molding or bolt fixing. Each connecting post corresponds to a stabilizing hole 524 and can be inserted into the stabilizing hole 524. One end of the elastic member 525 is connected to the bottom wall of the stabilizing hole 524, and the other end is connected to the end of the connecting post, thereby pulling the connecting post toward the adjustment cavity 521, thereby pulling the detection unit 200 to fit against the adjustment part 500, so as to enhance the stability of the detection unit 200. In some specific embodiments, the elastic member 525 is a spring; more specifically, when the first adjustment member 510 and the second adjustment member 540 cooperate to push the detection unit 200, the elastic member 525 pulls the detection unit 200 and the adjustment member closer to each other, while the connecting post is inserted into the stabilizing hole 524, thereby enhancing the stability of the detection unit 200 and preventing the stabilizing unit from shifting.

[0064] In some specific embodiments, the cross-section of the stabilizing hole 524 is trapezoidal, meaning the diameter of the opening of the stabilizing hole 524 is smaller than the diameter of the bottom wall of the stabilizing hole 524; thus reserving space for the deflection of the connecting column. More specifically, the cross-section of the connecting column is trapezoidal, meaning the bottom diameter of the connecting column is smaller than the top diameter of the connecting column; the side wall of the connecting column contacts the opening of the stabilizing hole 524, satisfying both the stability requirements when the detection unit 200 is horizontal and the stability requirements when the detection unit 200 is tilted.

[0065] In some more specific embodiments, for ease of understanding, a Cartesian coordinate system is established, distinguishing the first, second, third, and fourth quadrants. The center of the wafer is defined as coinciding with the origin, and the center of the adjustment unit 500 is also defined as coinciding with the origin. Ideally, the light emitted by the detection unit 200 should be focused on the origin. However, when it deviates from the first quadrant and the camera cannot receive the light reflected from the wafer, the first adjustment member 510 located in the third quadrant is adjusted to refocus the light on the origin. More specifically, this process can be broken down into: first, adjusting one or more first adjustment members 510 distributed along the X-direction within the third quadrant to move the focal point of the light to the X-axis of the Cartesian coordinate system; then, adjusting one or more first adjustment members 510 distributed along the Y-direction within the third quadrant to move the focal point of the light back to the origin. Meanwhile, since there are multiple elastic elements 525, during the angle adjustment process, due to the restriction of the elastic elements 525, the detection unit 200 may deflect to the second or fourth quadrant. In this case, it is sufficient to adjust the first adjusting element 510 in the corresponding quadrant to the appropriate position, which will not be elaborated here.

[0066] It is worth noting that when adjusting the first adjusting member 510 in the third quadrant, the control member 560 needs to pass through the fourth quadrant. This will cause the first adjusting member 510 in the fourth quadrant to move. At this time, it is only necessary to control the control member 560 to move in the opposite direction so that the first adjusting member 510 it has passed through can be reset. For example, when the control member 560 passes the first first adjusting member 510, the first adjusting member is set vertically. At this time, the control member 560 moves in the opposite direction so that the end of the first first adjusting member 510 abuts against the reset end. At this time, the first adjusting member 510 is set at an angle, and the control member 560 continues to move towards the third quadrant.

[0067] In some embodiments, the drive unit 400 includes a mounting body 410, a first drive member 420, a second drive member 430, and a connecting part 440. Specifically, the mounting body 410 has a mounting cavity; the connecting part 440 is disposed in the mounting cavity for connection with the adjustment unit 500; wherein, the connecting part 440 is block-shaped, its bottom contacts the bottom wall of the mounting cavity, and its top is fixedly connected to the bottom of the adjustment platform 520. The fixing method can be adhesive, snap-fit, or bolt fixing, etc., which is not limited here, as long as the two do not move relative to each other, so that the connecting part 440 can drive the adjustment unit 500 to move when it moves. The first drive member 420 extends along the X direction and is movably disposed in the mounting cavity along the Y direction; the second drive member 430 extends along the Y direction and is movably disposed in the mounting cavity along the X direction; both the first drive member 420 and the second drive member 430 pass through the connecting part 440; the first drive member 420 and the second drive member 430 cooperate to adjust the position of the connecting part 440. Specifically, both the first driving member 420 and the second driving member 430 are rod-shaped, and the first driving member 420 and the second driving member 430 are spaced apart in the vertical direction; at the same time, a track is provided in the mounting cavity, so that the first driving member 420 and the second driving member 430 can move in the corresponding track, and a motor is correspondingly provided in the track, and the motor can also move in the track; at the same time, the motor corresponding to the first driving member 420 is used to drive the first driving member 420 to rotate, and the motor corresponding to the second driving member 430 is used to drive the second driving member 430 to rotate. In addition, both the first driving member 420 and the second driving member 430 are threadedly connected to the connecting part 440; that is, when the motor drives the first driving member 420 to rotate, since the first driving member 420 is threadedly connected to the connecting part 440, the first driving member 420 drives the connecting part 440 and the second driving member 430 to move in the X direction; when the motor drives the second driving member 430 to rotate, since the second driving member 430 is threadedly connected to the connecting part 440, the second driving member 430 drives the connecting part 440 and the first driving member 420 to move in the Y direction.

[0068] In some specific embodiments, the bottom wall of the mounting cavity is provided with a track, and a connecting block is slidably arranged on the track. The first driving member 420 passes through the connecting block and can rotate around its own axis. There is no thread at the connection between the first driving member 420 and the connecting block, so that the rotation of the first driving member 420 will not affect the movement of the connecting block. The motor is arranged on the connecting block and connected to the first driving member 420, so as to facilitate the rotation of the first driving member 420. The second driving member 430 is arranged in the same way as the first driving member 420, and will not be described in detail here.

[0069] The implementation principle of the laser interferometric detection device for the end point of wafer etching in this application embodiment is as follows: the adjustment unit 500 and the detection unit 200 are controlled to move in the X or Y direction by the first driving member 420 and the second driving member 430, so that the light emitted by the detection unit 200 is focused on the area to be detected on the wafer surface; when the light emitted by the detection unit 200 is not focused on the area to be detected on the wafer surface and the camera cannot receive the light emitted by the wafer; or when the light emitted by the detection unit 200 is focused on the area to be detected on the wafer surface and the camera cannot receive the light emitted by the wafer, it indicates that the detection unit 200 is deflected. At this time, the deflection angle of the detection unit 200 is adjusted by controlling the first adjusting member 510 at different positions in the adjustment unit 500, so that the light emitted by the detection unit 200 is focused on the area to be detected on the wafer surface.

[0070] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A laser interferometry detection device for the end point of wafer etching, characterized in that, include: A carrier device (100) is used to carry the wafer; The detection unit (200), which is spaced apart from the carrier device (100), is used to emit detection light, which is focused onto the area to be detected on the surface of the wafer to detect the etching endpoint position of the wafer. A drive unit (300) includes a drive section (400) and an adjustment section (500). One end of the adjustment section (500) is connected to the drive section (400), and the other end is connected to the detection unit (200). The drive section (400) is used to drive the adjustment section (500) and the detection unit (200) to move along the X or Y direction. The adjustment section (500) includes a movable first adjustment member (510), which is placed at the bottom of the detection unit (200) and pushes the detection unit (200) to move during the movement, so as to adjust the deflection angle of the detection unit (200). The adjustment unit (500) also includes an adjustment platform (520), a drive component (530), and a control assembly; The top surface of the adjustment platform (520) is used to mount the detection unit (200), and the bottom surface of the detection unit (200) is attached to the top surface of the adjustment platform (520); the adjustment platform (520) has an adjustment cavity (521); the top surface of the adjustment platform (520) is provided with a plurality of adjustment holes (522) communicating with the adjustment cavity (521); the plurality of adjustment holes (522) are evenly distributed along the X and Y directions; One end of the first adjusting member (510) is disposed in the adjusting hole (522), and the other end is movably disposed in the bottom wall of the adjusting cavity (521); the driving member (530) is disposed in the side wall of the first adjusting member (510); The control component is located in the adjustment cavity (521) and is used to drive the drive member (530) to move so that the end of the first adjustment member (510) protrudes from the adjustment hole (522) and pushes the detection unit (200) to move, thereby adjusting the deflection angle of the detection unit (200). The adjustment part (500) further includes a second adjustment member (540); the second adjustment member (540) is disposed on the inner wall of the adjustment hole (522), and the second adjustment member (540) is made of flexible material; one end of the first adjustment member (510) is disposed on the end face of the second adjustment member (540).

2. The laser interferometric detection device according to claim 1, characterized in that, The thickness of the second adjusting element (540) is greater than or equal to 4 mm.

3. The laser interferometric detection device according to claim 1, characterized in that, The bottom of the adjustment cavity (521) is provided with a plurality of sliding grooves (523), each of the sliding grooves (523) corresponding to an adjustment hole (522); the other end of the second adjustment member (540) is movably disposed in the sliding groove (523).

4. The laser interferometric detection device according to claim 3, characterized in that, The bottom of the first adjusting member (510) is flat, so that when the first adjusting member (510) is vertically arranged, the bottom of the first adjusting member (510) is in contact with the bottom wall of the sliding groove (523).

5. The laser interferometry detection device according to claim 1, characterized in that, The control assembly includes a control lever (550), a control element (560), and a pusher (570); the control lever (550) is disposed within the adjustment cavity (521); the control element (560) is movably disposed within the control lever (550); a first control groove (561) is formed on the side wall of the control element (560), and a second control groove (562) is formed on the top wall of the first control groove (561); the pusher (570) is movably disposed within the second control groove (562). During the movement of the control member (560), the push member (570) contacts the drive member (530) to push the drive member (530) to move; when the drive member (530) moves to its limit position, the drive member (530) applies a force to the push member (570) to make the push member (570) move toward the bottom wall of the second control groove (562).

6. The laser interferometry detection device according to claim 5, characterized in that, The pusher (570) has symmetrically arranged push surfaces (571), the push surfaces (571) including a first contact section (572) and a second contact section (573); the angle between the first contact section (572) and the top wall of the first control groove (561) is greater than 45°; the angle between the second contact section (573) and the top wall of the first control groove (561) is less than 45°.

7. The laser interferometric detection device according to claim 1, characterized in that, The top surface of the adjustment platform (520) is provided with a plurality of stabilizing holes (524); the adjustment part (500) also includes an elastic element (525), one end of the elastic element (525) is provided on the bottom wall of the stabilizing hole (524), and the other end is provided on the bottom wall of the detection unit (200) to apply a force to the detection unit (200) to move toward the adjustment part (500).

8. The laser interferometric detection device according to claim 1, characterized in that, The drive unit (400) includes a mounting body (410), a first drive member (420), a second drive member (430), and a connecting part (440); the mounting body (410) has a mounting cavity; the connecting part (440) is disposed in the mounting cavity and is used to connect with the adjustment unit (500); the first drive member (420) extends along the X direction and is movably disposed in the mounting cavity along the Y direction; the second drive member (430) extends along the Y direction and is movably disposed in the mounting cavity along the X direction; both the first drive member (420) and the second drive member (430) pass through the connecting part (440); the first drive member (420) and the second drive member (430) cooperate to adjust the position of the connecting part (440).

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