A focusable monochromatic laser interferometry endpoint detection device

Abstract

This invention discloses a focusable monochromatic laser interferometry endpoint detection device, comprising a main body movably disposed above a process chamber; a connector disposed at the bottom of the main body, and the connector having a connection channel; a positioning component disposed on the connector and placed within the connection channel; and a focusing lens assembly, including a replacement housing and a lens group; the replacement housing is detachably disposed on the positioning component and includes a fixed section and an adjustment section, the adjustment section being movably disposed on the fixed section; the lens group includes a first fixed lens group, a focusing group, and a second fixed lens group arranged sequentially; the first fixed lens group is disposed on the fixed section and located above the adjustment section; the focusing group is disposed on the adjustment section; and the second fixed lens group is disposed on the fixed section and located below the adjustment section; wherein, adjusting the position of the adjustment section adjusts the focal length of the focusing lens assembly, and replacing the focusing lens assembly allows for replacement with lens groups of different focal length ranges. This invention expands the lens focal length adjustment range to adapt to and improve the endpoint detection accuracy of different etching processes.

Description

Technical Field

[0001] This invention relates to the field of semiconductor testing technology, and in particular to a focusable monochromatic laser interferometry endpoint detection device. Background Technology

[0002] In semiconductor manufacturing, dry etching is one of the key processes for forming the microstructure of devices. Precise control of the etching depth and real-time, accurate determination of the etching endpoint are crucial for ensuring device electrical performance and improving product yield. Among these technologies, monochromatic laser interferometry endpoint detection devices are used for endpoint detection in advanced etching processes due to their advantages of high precision, non-contact operation, and real-time monitoring.

[0003] The principle of a monochromatic laser interferometry endpoint detection device is as follows: a beam of highly monochromatic laser light is irradiated onto the thin film to be etched on the wafer surface. After the laser penetrates the transparent or semi-transparent film, it is reflected at both the upper and lower interfaces. The two reflected beams interfere due to the optical path difference. During the etching process, as the film thickness decreases uniformly, the intensity of the reflected light will exhibit periodic changes (i.e., interference fringes). By detecting the periodicity of the light intensity changes received by the detector, the etching depth can be inverted in real time. When the target interface (end point) is reached, an etching endpoint signal is emitted based on the specific changes in the interference signal. However, existing laser interferometry detection devices have significant limitations in practical applications. The focal length of their optical systems is usually fixed. This inherent design reveals the following problems when faced with complex semiconductor manufacturing processes: poor process adaptability; different etching processes (such as patterning etching and high aspect ratio contact hole etching) have different requirements for the topology of the wafer surface and the physical space within the process cavity; the fixed focal length lens cannot adapt to changes in the detection window position caused by process changes or the installation of cavity accessories (such as focusing rings); and its detection signal quality is easily interfered with. When the actual working distance exceeds the fixed focal length range of the lens, the laser beam cannot form the optimal focused spot on the wafer surface. This leads to attenuation of reflected light signal intensity, a significant decrease in signal-to-noise ratio, and a reduction in the contrast of interference fringes. At advanced micro-nano manufacturing nodes, the size of the features under test is increasingly shrinking, and the diffuse spot in a defocused state is more prone to signal averaging effects, further weakening the accuracy of detection. The risk of endpoint misjudgment is high; the low signal-to-noise ratio interference signal is highly susceptible to environmental interference such as plasma fluctuations and equipment vibrations, which may cause misjudgment by the endpoint detection system. Once endpoint misjudgment occurs (over-etching or under-etching), it will directly lead to incomplete etching (residual material layer) or over-etching (damage to the underlying material), causing the entire wafer to be scrapped and resulting in production losses. In particular, when transferring validated process formulations between different reaction chambers, even with the same model of equipment, mechanical tolerances can cause millimeter-level displacements in the detection window. Fixed-focal-length lenses cannot compensate for this displacement, making it difficult to guarantee process consistency between equipment.

[0004] Therefore, those skilled in the art urgently need a monochrome laser etching endpoint detection device that can overcome the above-mentioned shortcomings in order to solve the problems existing in the prior art. Summary of the Invention

[0005] The technical problem to be solved by this application is how to provide an adjustable focus monochromatic laser interferometry endpoint detection device that expands the lens focal length adjustment range to adapt to and improve the endpoint detection accuracy of different etching processes.

[0006] To address the aforementioned technical problems, according to embodiments of this application, a focusable monochromatic laser interferometry endpoint detection device is provided, comprising:

[0007] The main body is movable and positioned above the process chamber;

[0008] A connector is located at the bottom of the body, and the connector has a connection channel;

[0009] A positioning element is provided on the connector and placed within the connecting channel;

[0010] A focusing lens assembly includes a replacement housing and a lens assembly; the replacement housing is detachably disposed on the positioning member and includes a fixed section and an adjusting section, the adjusting section being movably disposed on the fixed section; the lens assembly includes a first fixed lens assembly, a focusing assembly, and a second fixed lens assembly arranged sequentially; the first fixed lens assembly is disposed on the fixed section and located above the adjusting section; the focusing assembly is disposed on the adjusting section; the second fixed lens assembly is disposed on the fixed section and located below the adjusting section;

[0011] Specifically, adjusting the position of the adjustment segment adjusts the focal length of the focusing lens group, and replacing the focusing lens group allows for the replacement of the lens group with different focal length ranges.

[0012] According to an embodiment of this application, the lens group further includes a beam splitter, which is disposed on the fixed section and located above the first fixed lens group; a light inlet is provided on the side wall of the fixed section, and the position of the light inlet corresponds to the position of the beam splitter;

[0013] The focusing lens assembly also includes a sealing cylinder and an elastic element; the sealing cylinder is movably sleeved on the fixed section to close or open the light inlet; one end of the elastic element is connected to the fixed section and the other end is connected to the sealing cylinder to drive the sealing cylinder to close the light inlet.

[0014] According to an embodiment of this application, the diameter of the connecting channel is greater than the diameter of the fixed section and less than the diameter of the sealing cylinder; the end of the connector is used to contact the sealing cylinder to push the sealing cylinder to open the light inlet when the fixed section moves toward the connecting channel.

[0015] According to an embodiment of this application, the sidewall of the fixed segment is provided with a first positioning groove and a second positioning groove; the first positioning groove is arranged around the sidewall of the fixed segment and has an angle with the end of the fixed segment; the second positioning groove is opened on the sidewall of the fixed segment and the second positioning groove is "C" shaped, one end of the second positioning groove is connected to the lowest point of the first positioning groove, and the other end is used to accommodate the positioning member;

[0016] Wherein, after the positioning member contacts the bottom wall of the first positioning groove, it moves along the bottom wall of the first positioning groove and enters the second positioning groove; after entering the second positioning groove, the fixed section is rotated so that the positioning member reaches the other end of the second positioning groove to cooperate with the sealing cylinder for positioning.

[0017] According to an embodiment of this application, a rotating cylinder is rotatably sleeved on the positioning member, and the diameter of the rotating cylinder is equal to the width of the second positioning groove.

[0018] According to an embodiment of this application, the focusing lens assembly further includes a sealing end cap and a linkage shaft disposed opposite to each other; the sealing end caps disposed opposite to each other are respectively disposed at both ends of the replacement housing to close both ends of the replacement housing; the linkage shaft passes through the side wall of the replacement housing in a vertical direction and connects the sealing end caps disposed opposite to each other, so that when one of the sealing end caps rotates, the other sealing end cap rotates synchronously.

[0019] According to an embodiment of this application, the end of the replacement housing is provided with a sealing ring; the surface roughness of the sealing end cap is less than or equal to 0.04 μm.

[0020] According to an embodiment of this application, the connecting member includes a fixing member and a rotating member; the positioning member is disposed on the rotating member, and the rotating member is rotatably disposed on the top of the fixing member; the body is provided with a follower member and a control member; the follower member engages with the rotating member to rotate synchronously when the rotating member rotates; one end of the control member is disposed on the follower member, and the other end is used to contact the sealing end cap on the top of the replacement housing to open the sealing end cap when the follower member rotates.

[0021] According to an embodiment of this application, the control component includes a rotating shaft section, a first receiving section, a second receiving section, a third receiving section, and a control section;

[0022] The rotating shaft section is located on the follower and is coaxially arranged with the follower;

[0023] The first receiving section and the third receiving section are parallel to each other, and one end of the first receiving section is located at the end of the rotating shaft section; one end of the second receiving section is located at the other end of the first receiving section, and the other end is located at the end of the third receiving section, so that the first receiving section, the second receiving section and the third receiving section form a receiving space to accommodate the sealing end cap;

[0024] The length of the third receiving section is greater than the length of the first receiving section, and the control section is located at the end of the first receiving section to drive the sealing end cap to rotate when the rotating shaft section rotates.

[0025] According to an embodiment of this application, the bottom end of the rotating member is provided with a locking member; the top end of the fixing member is provided with a first locking hole and a second locking hole, the included angle between the first locking hole and the second locking hole is 45°; and both the first locking hole and the second locking hole are used to insert the locking member.

[0026] When the locking member is located in the first locking hole, the control member is placed at the edge of the sealing end cover; when the locking member moves from the first locking hole to the second locking hole, the control member rotates by a corresponding angle and opens the sealing end cover.

[0027] By adopting the above technical solution, adjusting the position of the adjustment section within the fixed section allows for the adjustment of the focal length of a single focusing lens group. By replacing the focusing lens group with different focal length ranges, the maximum focal length range can be adjusted, thus exceeding the limitations of a single focusing lens group's focal length range and adapting to different focal length requirements. Furthermore, sealing end caps are provided at both ends of the replacement housing. After the focusing lens group is installed in the connecting channel, continuing to rotate the focusing lens group drives the rotating component to rotate, thereby rotating the control component and opening the sealing end caps. This allows the sealing end caps to be opened from the inside only after the focusing lens group is installed, reducing the possibility of contamination of the focusing lens group's interior by impurities. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the main structure of an adjustable focus monochromatic laser interferometry endpoint detection device according to an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of a focusing lens assembly installed in a connecting channel according to an embodiment of the present invention;

[0030] Figure 3 This is a cross-sectional view of a focusing lens assembly installed in a connecting channel according to an embodiment of the present invention;

[0031] Figure 4 for Figure 3 Enlarged view of section A in the middle;

[0032] Figure 5 for Figure 3 Enlarged view of section B;

[0033] Figure 6 This is a schematic diagram showing the positions of a first positioning groove and a second positioning groove according to an embodiment of the present invention.

[0034] Figure 7 This is a schematic diagram illustrating the positional relationship between a positioning element and a second positioning groove in an embodiment of the present invention.

[0035] Figure 8 This is a schematic diagram illustrating the positional relationship of a control component when it does not rotate the sealing end cap, according to an embodiment of the present invention.

[0036] Figure 9 This is a schematic diagram showing the positional relationship of a control component driving the sealing end cap to rotate according to an embodiment of the present invention.

[0037] Figure 10 This is a schematic diagram showing the position of a locking element according to an embodiment of the present invention;

[0038] Figure 11 This is a schematic diagram showing the positions of the first locking hole and the second locking hole on the fastener according to an embodiment of the present invention.

[0039] Figure label:

[0040] 100. Body; 200. Connector; 201. Connecting channel; 210. Fixing component; 211. First locking hole; 212. Second locking hole; 220. Rotating component; 221. Locking component; 300. Positioning component; 310. Rotating cylinder; 400. Focusing lens group; 410. Replacement housing; 411. Fixing section; 4111. Light inlet; 4112. First positioning groove; 4113. Second positioning groove; 412. Adjustment section; 413. Sealing... 420. Sealing ring; 421. Lens group; 422. First fixed lens group; 423. Focusing group; 424. Second fixed lens group; 425. Beam splitter; 430. Sealing cylinder; 440. Elastic element; 450. Sealing end cap; 460. Linkage shaft; 500. Follower element; 600. Control element; 610. Rotating shaft section; 620. First receiving section; 630. Second receiving section; 640. Third receiving section; 650. Control section; 700. Operating ring. Detailed Implementation

[0041] 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.

[0042] The following is in conjunction with the appendix Figures 1-11 The specific embodiments of the present invention will be further described in detail below.

[0043] This invention provides a focusable monochromatic laser interferometry endpoint detection device for detecting the etching endpoint of a wafer. Specifically, the device is applied to endpoint detection in the etching process of a semiconductor 3D NAND structure. For example, in 3D NAND memory manufacturing, it is necessary to etch through dozens to hundreds of alternating stacked dielectric layer pairs (such as SiO2 / SiN) to form high aspect ratio vias. Precise control of the etching depth, ensuring that the vias completely penetrate the stacked layers and stop on the bottom silicon substrate, is crucial. Traditional fixed-focus laser interferometry struggles to address signal attenuation issues caused by increased hole depth during etching, and inaccurate endpoint determination can easily lead to under-etching or over-etching. This embodiment, through the initial and dynamic focusing of the focusing lens group 400, ensures a strong and stable interference signal throughout the deep-hole etching process, effectively overcoming the signal attenuation problem. By combining the dual criteria of amplitude attenuation and frequency abrupt change, the accuracy and reliability of endpoint detection on complex 3D structures are greatly improved, successfully achieving precise control of the etching process. More specifically, the wafer is placed inside the process chamber, and the inspection device is positioned above and spaced apart from the process chamber. The inspection device can move vertically or horizontally above the process chamber; this is existing technology and will not be elaborated upon here. Specifically, the inspection device includes:

[0044] The main body 100 is movably positioned above the process chamber;

[0045] The connector 200 is located at the bottom of the body 100, and the connector 200 has a connection channel 201;

[0046] Positioning element 300 is provided on connector 200 and placed in connecting channel 201;

[0047] The focusing lens assembly 400 includes a replacement housing 410 and a lens assembly 420. The replacement housing 410 is detachably disposed on the positioning member 300 and includes a fixed section 411 and an adjusting section 412, with the adjusting section 412 movably disposed on the fixed section 411. The lens assembly 420 includes a first fixed lens assembly 421, a focusing assembly 422, and a second fixed lens assembly 423 arranged sequentially. The first fixed lens assembly 421 is disposed on the fixed section 411 and located above the adjusting section 412. The focusing assembly 422 is disposed on the adjusting section 412. The second fixed lens assembly 423 is disposed on the fixed section 411 and located below the adjusting section 412.

[0048] The position of the adjustment section 412 is adjusted to adjust the focal length of the focusing lens group 400, and the focusing lens group 400 is replaced to replace the lens group 420 with different focal length ranges.

[0049] In some embodiments, the bottom of the body 100 has a mounting hole, allowing the interior of the body 100 to communicate with the exterior. The connector 200 is cylindrical and fixed to the inner wall of the mounting hole. Its installation method can be adhesive, snap-fit, or bolted, etc., without limitation, as long as the connector 200 does not separate from the body 100. Simultaneously, a connecting channel 201 is provided on the connector 200, which passes through the connector 200 vertically to facilitate the installation of the focusing lens assembly 400. A positioning member 300 is provided on the inner wall of the connecting channel 201. The positioning member 300 is rod-shaped and forms a protrusion on the inner wall of the connecting channel 201. The positioning member 300 can be fixed to the inner wall of the connecting channel 201 by adhesive, snap-fit, or integral molding, etc., without limitation, as long as the position of the positioning member 300 within the connecting channel 201 does not change.

[0050] In some embodiments, the replacement housing 410 is cylindrical and detachably disposed on the positioning member 300; the replacement housing 410 includes a fixed section 411 and an adjusting section 412, wherein the fixed section 411 and the adjusting section 412 are cylindrical, and the adjusting section 412 passes through the interior of the fixed section 411; specifically, the side wall of the fixed section 411 is provided with an adjusting groove, the adjusting groove passes through the side wall of the fixed section 411 and the length direction of the adjusting groove is parallel to the axial direction of the fixed section 411, and the outer wall of the adjusting section 412 is provided with an adjusting protrusion, the adjusting protrusion passes through the adjusting groove, so that the adjusting section 412 can move vertically along the inner wall of the fixed section 411. More specifically, to facilitate the control of the movement of the adjusting section 412, an operating cylinder is sleeved on the outside of the fixed section 411. An operating channel is provided on the side wall of the operating cylinder, which passes through the side wall of the operating cylinder radially and is inclined. At the same time, the adjusting protrusion passes through the operating channel. When the operating cylinder is rotated, the operating channel and the adjusting groove together limit the adjusting protrusion, causing the adjusting protrusion to move upward or downward along the length of the adjusting groove. This control method is existing technology in the field and will not be described in detail here.

[0051] In some specific embodiments, the fixing methods of the first lens group 420 and the third lens group 420 in the fixed section 411 and the fixing methods of the second lens group 420 in the adjusting section 412 can be adhesive or snap-fit, without limitation, as long as the positions of the first lens group 420 and the third lens group 420 in the fixed section 411 do not change and the position of the second lens group 420 in the adjusting section 412 does not change. Specifically, the first fixed lens group 421 may contain one, two, or more lenses, without limitation. The number of lenses in the first fixed lens group 421 can be set according to the usage requirements during use. The third fixed lens group 420 may contain one, two, or more lenses, without limitation. The number of lenses in the first fixed lens group 421 can be set according to the usage requirements during use. The second lens group 420 contains one lens. Since the second adjustment group is located in the adjustment section 412, the lens in the second lens group 420 can move synchronously with the adjustment section 412 during the movement of the adjustment section 412, thereby changing the interval between the second lens group 420 and the first lens group 420, and thus realizing the adjustment of the focal length of the focusing lens group 400. More specifically, by adjusting the position of the adjustment segment 412 within the fixed segment 411, the focal length of a single focusing lens group 400 can be adjusted; by replacing the focusing lens group 400 with different focal length ranges, the maximum focal length range can be adjusted, thereby exceeding the limitation of the focal length range of a single focusing lens group 400, thus adapting to different focal length range requirements.

[0052] In some embodiments, the lens group 420 further includes a beam splitter 424, which is disposed on the fixed section 411 and located above the first fixed lens group 421. The side wall of the fixed section 411 has a light inlet 4111, the position of which corresponds to the position of the beam splitter 424. The beam splitter 424 can be one, two, or more, which is not limited here and can be set according to the usage requirements. Taking the setting of two beam splitters 424 as an example, the number of light inlets 4111 corresponds to the number of beam splitters 424, so there are two light inlets 4111. Both light inlets 4111 penetrate the side wall of the fixed section 411 along the radial direction of the fixed section 411, so that the light inside the body 100 can pass through the corresponding light inlet 4111 and illuminate the beam splitter 424. More specifically, the body 100 is equipped with an illumination source and a laser. The illumination source is set with one light inlet 4111, and the illumination light emitted by the illumination source can be irradiated by the corresponding beam splitter 424 through the corresponding light inlet 4111, so as to be reflected by the beam splitter 424 onto the wafer surface. The laser is set with another light inlet 4111, and the laser emitted by the laser can be irradiated by the corresponding beam splitter 424 through the corresponding light inlet 4111, so as to be reflected by the beam splitter 424 onto the wafer surface.

[0053] In some embodiments, to ensure the cleanliness of the beam splitter 424 when the focusing lens assembly 400 is not in use, the focusing lens assembly 400 further includes a sealing cylinder 430 and an elastic element 440. The sealing cylinder 430 is movably fitted onto the fixed section 411 to close or open the light inlet 4111. Specifically, the side wall of the fixed section 411 has a reset groove, the length of which is parallel to the axis of the fixed section 411. The inner wall of the sealing cylinder 430 has a reset protrusion. The reset protrusion can be attached, snap-fitted, or bolted, etc., without limitation, as long as its position within the sealing cylinder 430 does not change. The reset protrusion passes through the reset groove, thereby limiting the movement distance of the reset cylinder. More specifically, the elastic element 440 is a spring, located in the reset groove, with one end connected to the fixed section 411 and the other end connected to the sealing cylinder 430, thereby causing the sealing cylinder 430 to close the light inlet 4111. Specifically, one end of the elastic element 440 is fixed to the top of the reset groove, and the other end is fixed to the reset protrusion, thereby pulling the sealing cylinder 430 to close the light inlet 4111 and reducing the influence of dust on the beam splitter 424.

[0054] In some embodiments, the diameter of the connecting channel 201 is larger than the diameter of the fixed section 411 but smaller than the diameter of the sealing cylinder 430. The end of the connector 200 is used to contact the sealing cylinder 430 to push the sealing cylinder 430 to open the light inlet 4111 when the fixed section 411 moves into the connecting channel 201. Specifically, during the installation of the focusing lens assembly 400, the fixed section 411 can extend into the interior of the connecting channel 201, while the sealing cylinder 430 cannot extend into the interior of the connecting channel 201. During the process of the fixed section 411 extending into the connecting channel 201, the end of the sealing cylinder 430 abuts against the end of the connector 200, thereby causing the sealing cylinder 430 to move relative to the bottom of the fixed section 411 when the fixed section 411 moves, thus opening the light inlet 4111. This allows light to enter the focusing lens assembly 400 from the light inlet 4111 after the focusing lens assembly 400 is installed.

[0055] In some embodiments, to facilitate the connection between the focusing lens assembly 400 and the positioning member 300, a first positioning groove 4112 and a second positioning groove 4113 are provided on the side wall of the fixed section 411. The first positioning groove 4112 surrounds the side wall of the fixed section 411 and forms an angle with the end of the fixed section 411; that is, the bottom surface of the first positioning groove 4112 is inclined. When the replacement housing 410 moves towards the connecting channel 201, the positioning member 300 can move to the lowest point of the bottom surface of the first positioning groove 4112 regardless of where it contacts the bottom surface of the first positioning groove 4112. The second positioning groove 4113 is provided on the side wall of the fixed section 411 and is C-shaped, meaning the second positioning groove 4113 has a main groove and two side grooves connected to the main groove, with the side grooves extending upwards in a vertical direction. One end of the second positioning groove 4113 is connected to the lowest point of the first positioning groove 4112, and the other end is used to accommodate the positioning member 300; that is, one side groove of the second positioning groove 4113 is connected to the lowest point of the first positioning groove 4112, and the other side groove is used to accommodate the positioning member 300.

[0056] In some specific embodiments, when the positioning member 300 contacts the first positioning groove 4112, the positioning member 300 is not at the lowest point of the first positioning groove 4112. Therefore, when the positioning member 300 moves towards the lowest point of the first positioning groove 4112, the focusing lens assembly 400 will rotate. To facilitate the rotation of the focusing lens assembly 400, an operating ring 700 is provided on the replacement housing 410. Specifically, a rotating groove is provided on the fixed section 411, which surrounds the outer wall of the fixed section 411. At the same time, a bearing is embedded in the rotating groove, and the operating ring 700 is sleeved on the bearing, with the inner wall of the operating ring 700 and the outer wall of the bearing having an interference fit to reduce the friction between the operating ring 700 and the replacement housing 410.

[0057] In some more specific embodiments, after the focusing lens assembly 400 is inserted into the connecting channel 201, the side wall of the positioning member 300 contacts the bottom wall of the first positioning groove 4112. Since the bottom wall of the first positioning groove 4112 is inclined, the positioning member 300 moves along the bottom wall of the first positioning groove 4112 after contacting the bottom wall of the first positioning groove 4112, reaches the lowest point of the bottom wall of the first positioning groove 4112, and enters the second positioning groove 4113. During this process, a person needs to grasp the operating ring 700 so that the replacement housing 410 can rotate, allowing the positioning member 300 to enter the second positioning groove 4113.

[0058] In some more specific embodiments, after entering the second positioning groove 4113, the fixed section 411 is rotated so that the positioning member 300 reaches the other end of the second positioning groove 4113 to cooperate with the sealing cylinder 430 for positioning. Specifically, the positioning member 300 first enters one side groove of the second positioning groove 4113. At this time, the operating ring 700 is released, and the replacement housing 410 is pushed to allow the positioning member 300 to enter the main groove of the second positioning groove 4113. At this time, the replacement housing 410 is controlled to rotate so that the positioning member 300 corresponds to the other side groove of the second positioning groove 4113. The replacement housing 410 is then released, and under the weight of the replacement housing 410 and the action of the elastic member 440, the positioning member 300 enters the other side groove of the second positioning groove 4113, completing the installation of the focusing lens assembly 400. The disassembly process is the reverse of the installation process and will not be described in detail here.

[0059] In some embodiments, a rotating cylinder 310 is rotatably sleeved on the positioning member 300, and the diameter of the rotating cylinder 310 is equal to the width of the second positioning groove 4113. Specifically, since the positioning member 300 is provided with a sleeve, the contact between the positioning member 300 and the bottom wall of the first positioning groove 4112 is actually the contact between the side wall of the sleeve and the bottom wall of the first positioning groove 4112, thereby converting sliding friction into rolling friction, thus reducing the frictional force between the positioning member 300 and the bottom wall of the first positioning groove 4112, facilitating the rotation process of the replacement housing 410. In addition, the width of the two side grooves of the second positioning groove 4113 is the same as the width of the main groove. Since the diameter of the rotating cylinder 310 is equal to the width of the second positioning groove 4113, when the positioning member 300 enters the corresponding side groove of the second positioning groove 4113, the position of the positioning member 300 in the corresponding side groove of the second positioning groove 4113 will not shift, so that the focusing lens assembly 400 will not rotate on its own after installation. In addition, after the focusing lens assembly 400 is installed, the elastic element 440 is stretched due to the positional shift of the sealing cylinder 430. Therefore, the elastic element 440 applies a downward vertical force to the fixed section 411, causing the positioning element 300 to abut against the inner wall of the second positioning groove 4113, thereby enhancing the stability of the focusing lens assembly 400. It is worth noting that, to facilitate the sealing of the light inlet 4111 by the sealing cylinder 430, the position of the light inlet 4111 is spaced from the highest point of the bottom wall of the first positioning groove 4112.

[0060] In some embodiments, the focusing lens assembly 400 further includes a sealing end cap 450 and a linkage shaft 460 disposed opposite to each other; wherein the sealing end cap 450 is plate-shaped, and the oppositely disposed sealing end caps 450 are respectively disposed at both ends of the replacement housing 410 to seal both ends of the replacement housing 410; thereby reducing the possibility that impurities may enter the focusing lens assembly 400 from both ends when the focusing lens assembly 400 is not in use, thus causing the lens to be contaminated.

[0061] In some embodiments, the linkage shaft 460 extends vertically through the side wall of the replacement housing 410 and connects to the oppositely disposed sealing end caps 450, so that when one sealing end cap 450 rotates, the other sealing end cap 450 rotates synchronously. Specifically, the side wall of the replacement housing 410 has a through hole extending vertically, the linkage shaft passes through the through hole, and one end of the linkage shaft 460 is fixedly connected to one of the sealing end caps 450, and the other end of the linkage shaft 460 is fixedly connected to the other sealing end cap 450. The two sealing end caps 450 cooperate to close both ends of the replacement housing 410, so that when the focusing lens assembly 400 is not in use, impurities cannot enter the interior of the focusing lens assembly 400. In some specific embodiments, a torsion spring can be provided in the through hole to facilitate reset after the sealing end cover 450 is opened, while reducing the possibility that the sealing end cover 450 will open on its own without external force. The torsion spring is provided in the prior art, for example, by opening grooves on the bottom wall of the sealing end cover 450 and the inner wall of the through hole to accommodate the two ends of the torsion spring so that the torsion spring has a reset function. The specific setting method will not be described in detail here.

[0062] In some embodiments, a sealing ring 413 is provided at the end of the replacement housing 410. Specifically, the sealing ring 413 is embedded in the end of the replacement housing 410, and the cross-section of the sealing ring 413 is circular. The height of the sealing ring 413 protruding from the end of the replacement housing 410 is less than the radius of the circle of the cross-section of the sealing ring 413. That is, the portion of the sealing ring 413 protruding from the end of the replacement housing 410 is arc-shaped, thereby facilitating the sealing end cap 450 to abut against the sealing ring 413 during rotation. In some specific embodiments, the material of the sealing ring 413 can be silicone or rubber, without limitation, as long as it can cooperate with the sealing end cap 450 to achieve a sealing effect. In some more specific embodiments, the surface roughness of the sealing end cap 450 is less than or equal to 0.04 μm, which can be 0.04 μm, 0.03 μm or 0.02 μm to make the surface of the sealing end cap 450 smooth, thereby reducing the friction between the sealing end cap 450 and the sealing ring 413, and at the same time enhancing the sealing performance between the sealing end cap 450 and the sealing ring 413.

[0063] In some embodiments, since the sealing end caps 450 close both ends of the replacement housing 410, and the two sealing end caps 450 move synchronously, the replacement housing 410 needs to be installed into the connecting channel 201 before the sealing end caps 450 are opened. Therefore, to facilitate the opening of the sealing end caps 450, the connecting member 200 includes a fixing member 210 and a rotating member 220; both the fixing member 210 and the rotating member 220 are cylindrical and coaxially arranged. The fixing member 210 is fixedly disposed at the bottom of the body 100, and its fixing method can be adhesive, snap-fit, or integral molding, etc., which is not limited here, as long as the position of the fixing member 210 on the body 100 does not move. The positioning member 300 is disposed on the inner wall of the rotating member 220, and the rotating member 220 is rotatably disposed on the top of the fixing member 210; at the same time, the rotational resistance of the rotating member 220 is greater than the rotational resistance of the focusing lens group 400, so that the rotating member 220 will not rotate during the installation of the focusing lens group 400.

[0064] In some specific embodiments, the body 100 is provided with a follower 500 and a control member 600; the follower 500 meshes with the rotating member 220 to rotate synchronously when the rotating member 220 rotates; one end of the control member 600 is disposed on the follower 500, and the other end is used to contact the sealing end cover 450 on the top of the replacement housing 410 to open the sealing end cover 450 when the follower 500 rotates. Specifically, a first gear is sleeved on the outer wall of the rotating member 220, and the follower 500 is a second gear. The follower 500 is rotatably disposed inside the body 100 via a rotating shaft. Since the follower 500 meshes with the rotating member 220, the rotating member 220 will drive the follower 500 to rotate synchronously when it rotates; at the same time, the control member 600 is fixedly disposed on the follower 500. Its setting method can be adhesive, snap-fit, or bolted, etc., which is not limited here, with the main point being that the control member 600 and the follower 500 can rotate synchronously. Furthermore, the end of the control component 600 contacts the sealing cover on the top of the replacement housing 410. During the rotation of the rotating component 220, the follower component 500 rotates synchronously, thereby driving the control component 600 to rotate. During the movement, the control component 600 contacts the sealing cover on the top of the replacement housing 410, thereby driving the sealing end cover 450 to rotate around the linkage shaft 460, thereby opening the end of the replacement housing 410 to facilitate the operation process. That is, the light from the illumination source can be reflected by the beam splitter 424 and pass through multiple lens groups 420 to illuminate the wafer surface. After being reflected by the wafer surface, it passes through multiple lens groups 420 and beam splitter 424 in sequence, and is received by the camera located inside the body 100 and above the focusing lens group 400.

[0065] In some embodiments, to limit the rotation angle of the control member 600 driving the sealing end cap 450, a locking member 221 is provided at the bottom of the rotating member 220. Specifically, a locking groove is provided at the bottom of the rotating member 220, and the locking member 221 is movably disposed within the locking member 221 in the vertical direction and will not disengage from the locking groove. This arrangement is prior art and will not be described in detail here. A spring is also provided in the locking groove, with one end of the spring abutting against the bottom wall of the locking groove and the other end abutting against the locking member 221 to push the locking member 221 to move out of the locking groove. In addition, the side wall of the locking member 221 is arc-shaped so that it can be retracted into the locking groove under force during the rotation of the rotating member 220.

[0066] In some embodiments, the top end of the fixing member 210 is provided with a first locking hole 211 and a second locking hole 212. The shapes of the first locking hole 211 and the second locking hole 212 are adapted to the shape of the locking member 221, and the included angle between the first locking hole 211 and the second locking hole 212 is 45°. Both the first locking hole 211 and the second locking hole 212 are used to pass through the locking member 221. Specifically, when the locking member 221 is passed through the first locking hole 211, the position of the linkage shaft 460 is close to the control member 600. At this time, the rotation of the control member 600 can push the sealing end cover 450 to rotate around the linkage shaft 460, thereby opening the sealing end cover 450.

[0067] In some specific embodiments, when the locking member 221 is located in the first locking hole 211, the control member 600 is placed at the edge of the sealing end cover 450. At this time, the positioning member 300 passes through the side groove of the second positioning groove 4113, controlling the rotation of the replacement housing 410. Since the side groove of the second positioning groove 4113 has a limiting effect on the positioning member 300, the rotating member 220 will rotate synchronously with the replacement housing 410. At the same time, since the locking member 221 is arc-shaped, the locking member 221 retracts into the locking groove until the position of the locking member 221 rotates to the second locking hole 212 and extends out. At this time, the follower 500 rotates synchronously with the rotating member 220, and the control member 600 rotates with the follower 500, contacts the sealing end cover 450, and drives the sealing end cover 450 to rotate around the linkage shaft 460, thus sealing the end cover 450. That is, when the locking member 221 moves from the first locking hole 211 to the second locking hole 212, the control member 600 rotates the corresponding angle and opens the sealing end cover 450.

[0068] In some more specific embodiments, the inner diameter of the fixing member 210 is the same as the inner diameter of the rotating member 220. The bottom of the rotating member 220 is integrally formed with a connecting ring, which is sleeved on the outer wall of the fixing member 210. The inner wall of the connecting ring is provided with a groove, and the outer wall of the fixing member 210 is integrally formed with a protrusion that passes through the groove, so that the rotating member 220 is rotatably disposed on the fixing member 210 to facilitate the rotation of the follower member 500.

[0069] In some embodiments, in order to reduce the collision between the sealing end cap 450 and the control member 600 when it is opened, the control member 600 is provided to include a pivot section 610, a first receiving section 620, a second receiving section 630, a third receiving section 640 and a control section 650.

[0070] The rotating shaft section 610 is located on the follower 500 and is coaxial with the follower 500; so that when the follower 500 rotates, it can drive the rotating shaft section 610 to rotate synchronously with the follower 500, and the rotating shaft section 610 can rotate around its own axis.

[0071] The first receiving section 620 and the third receiving section 640 are parallel to each other, with one end of the first receiving section 620 located at the end of the rotating shaft section 610. One end of the second receiving section 630 is located at the other end of the first receiving section 620, and the other end is located at the end of the third receiving section 640, so that the first receiving section 620, the second receiving section 630, and the third receiving section 640 form a receiving space to accommodate the sealing end cap 450. Specifically, the rotating shaft section 610 is vertically arranged, the first receiving section 620 is horizontally arranged, and one end of the first receiving section 620 is fixedly located at the top of the rotating shaft section 610 to connect the first receiving section 620 to the rotating shaft section 610. The second receiving section 630 is vertically arranged and fixedly located at the end of the first receiving section 620 away from the rotating shaft section 610. The third receiving section 640 is horizontally positioned, parallel to the first receiving section 620, with its end fixed to the end of the second receiving section 630 furthest from the first receiving section 620. This creates a receiving space formed by the first receiving section 620, the second receiving section 630, and the third receiving section 640. The length of the first receiving section 620 is greater than two-thirds of the diameter of the sealing end cap 450. Specifically, since the sum of the radius of the follower 500 and the length of the first receiving section is greater than the diameter of the sealing end cap 450, and the receiving space is used to accommodate the sealing end cap 450, the sealing end cap 450, when opened and placed within the receiving space, will not collide with the control component 600, thus preventing damage to either the sealing end cap 450 or the control component 600.

[0072] In some embodiments, the length of the third receiving section 640 is greater than the length of the first receiving section 620, and the control section 650 is located at the end of the first receiving section 620 to drive the sealing end cap 450 to rotate when the rotating shaft section 610 rotates. Specifically, the control section 650 is vertically arranged and fixedly located at the end of the third receiving section 640 away from the second receiving section 630. During the rotation of the control member 600, the control section 650 tends to rotate around the rotating shaft section 610 and pushes the sealing end cap 450 to open it. At the same time, the length of the third receiving section 640 is adapted to the positions of the first locking hole 211 and the second locking hole 212 so that after the locking member 221 moves to the second locking hole 212, the sealing end cap 450 will not block the end of the replacement housing 410. The closing method of the sealing end cap 450 is the opposite of the opening method, and will not be described in detail here. It is worth noting that when the sealing end cover 450 is opened, the light inlet 4111 is positioned directly opposite the illumination source inside the body 100, so that the light from the illumination source can enter the focusing lens assembly 400. Simultaneously, the sealing end cover 450 located at the bottom of the replacement housing 410 will not interfere with the body 100. More specifically, when the rotating component 220 rotates, the replacement housing 410 and the control component 600 rotate synchronously. By setting the distance between the control component 600 and the replacement housing 410, the rotating component 220 rotates 45°, meaning that when the locking component 221 moves from the first locking hole 211 to the second locking hole 212, the sealing end cover 450 is fully opened. It is worth noting that the angle between the first locking hole 211 and the second locking hole 212 can also be 30°, 60°, or other angles; this is not limited here. It can be set according to usage requirements during actual use, and the distance between the control component 600 and the replacement housing 410 can be adjusted accordingly, i.e., the length of the third receiving section 640 can be adjusted.

[0073] The implementation principle of the adjustable-focus monochromatic laser interferometry endpoint detection device in this application is as follows: by adjusting the position of the adjustment section 412 within the fixed section 411, the focal length of a single focusing lens group 400 can be adjusted; by replacing the focusing lens group 400 with different focal length ranges, the maximum focal length range can be adjusted, thereby exceeding the limitation of the focal length range of a single focusing lens group 400, thus adapting to different focal length range requirements. In addition, sealing end caps 450 are provided at both ends of the replacement housing 410. After the focusing lens group 400 is installed in the connecting channel 201, continuing to rotate the focusing lens group 400 can drive the rotating component 220 to rotate, thereby causing the control component 600 to rotate and opening the sealing end caps 450. This allows the sealing end caps 450 to be opened from the inside after the focusing lens group 400 is installed, reducing the possibility of contamination of the inside of the focusing lens group 400 by impurities.

[0074] 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 focusable monochromatic laser interferometry endpoint detection device, applied to the endpoint detection of semiconductor etching processes, characterized in that, include: The main body (100) is movably located above the process chamber; A connector (200) is provided at the bottom of the body (100), and the connector (200) has a connection channel (201); A positioning element (300) is disposed on the connector (200) and placed within the connecting channel (201); A focusing lens assembly (400) includes a replacement housing (410) and a lens assembly (420); the replacement housing (410) is detachably disposed on the positioning member (300) and includes a fixed section (411) and an adjusting section (412), the adjusting section (412) being movably disposed on the fixed section (411); the lens assembly (420) includes a first fixed lens assembly (421), a focusing assembly (422), and a second fixed lens assembly (423) arranged sequentially; the first fixed lens assembly (421) is disposed on the fixed section (411) and located above the adjusting section (412); the focusing assembly (422) is disposed on the adjusting section (412); the second fixed lens assembly (423) is disposed on the fixed section (411) and located below the adjusting section (412); The position of the adjustment segment (412) is adjusted to adjust the focal length of the focusing lens group (400), and the focusing lens group (400) is replaced to replace the lens group (420) with different focal length ranges. The focusing lens assembly (400) further includes a sealing end cap (450) and a linkage shaft (460) disposed opposite to each other; the sealing end caps (450) are respectively disposed at both ends of the replacement housing (410) to close both ends of the replacement housing (410); the linkage shaft (460) passes through the side wall of the replacement housing (410) in a vertical direction and connects the sealing end caps (450) disposed opposite to each other, so that when one of the sealing end caps (450) rotates, the other sealing end cap (450) rotates synchronously; The connecting member (200) includes a fixing member (210) and a rotating member (220); the positioning member (300) is disposed on the rotating member (220), and the rotating member (220) is rotatably disposed on the top of the fixing member (210); the body (100) is provided with a follower member (500) and a control member (600); the follower member (500) engages with the rotating member (220) to rotate synchronously when the rotating member (220) rotates; One end of the control element (600) is disposed on the follower (500), and the other end is used to contact the sealing end cap (450) on the top of the replacement housing (410) to open the sealing end cap (450) when the follower (500) rotates.

2. The adjustable-focus monochromatic laser interferometry endpoint detection device according to claim 1, characterized in that, The lens group (420) further includes a beam splitter (424), which is disposed on the fixed section (411) and located above the first fixed lens group (421); the side wall of the fixed section (411) is provided with a light inlet (4111), and the position of the light inlet (4111) corresponds to the position of the beam splitter (424); The focusing lens assembly (400) further includes a sealing cylinder (430) and an elastic element (440); the sealing cylinder (430) is movably sleeved on the fixed section (411) to close or open the light inlet (4111); one end of the elastic element (440) is connected to the fixed section (411), and the other end is connected to the sealing cylinder (430) to drive the sealing cylinder (430) to close the light inlet (4111).

3. The adjustable-focus monochromatic laser interferometry endpoint detection device according to claim 2, characterized in that, The diameter of the connecting channel (201) is larger than the diameter of the fixed section (411) and smaller than the diameter of the sealing cylinder (430); the end of the connector (200) is used to contact the sealing cylinder (430) to push the sealing cylinder (430) to open the light inlet (4111) when the fixed section (411) moves toward the connecting channel (201).

4. The adjustable-focus monochromatic laser interferometry endpoint detection device according to claim 2, characterized in that, The sidewall of the fixed section (411) is provided with a first positioning groove (4112) and a second positioning groove (4113); the first positioning groove (4112) is arranged around the sidewall of the fixed section (411) and has an angle with the end of the fixed section (411); the second positioning groove (4113) is opened on the sidewall of the fixed section (411) and the second positioning groove (4113) is "C" shaped, one end of the second positioning groove (4113) is connected to the lowest point of the first positioning groove (4112), and the other end is used to accommodate the positioning member (300); Wherein, after the positioning member (300) contacts the bottom wall of the first positioning groove (4112), it moves along the bottom wall of the first positioning groove (4112) and enters the second positioning groove (4113); after entering the second positioning groove (4113), the fixed section (411) is rotated so that the positioning member (300) reaches the other end of the second positioning groove (4113) to cooperate with the sealing cylinder (430) for positioning.

5. The adjustable-focus monochromatic laser interferometry endpoint detection device according to claim 4, characterized in that, A rotating cylinder (310) is rotatably sleeved on the positioning member (300), the diameter of which is equal to the width of the second positioning groove (4113).

6. The adjustable-focus monochromatic laser interferometry endpoint detection device according to claim 1, characterized in that, The replacement housing (410) is provided with a sealing ring (413) at its end; the surface roughness of the sealing end cap (450) is less than or equal to 0.04 μm.

7. The adjustable-focus monochromatic laser interferometry endpoint detection device according to claim 1, characterized in that, The control component (600) includes a rotating shaft section (610), a first receiving section (620), a second receiving section (630), a third receiving section (640), and a control section (650); The rotating shaft section (610) is disposed on the follower (500) and is coaxially arranged with the follower (500); The first receiving section (620) and the third receiving section (640) are parallel to each other, and one end of the first receiving section (620) is located at the end of the rotating shaft section (610); one end of the second receiving section (630) is located at the other end of the first receiving section (620), and the other end is located at the end of the third receiving section (640), so that the first receiving section (620), the second receiving section (630) and the third receiving section (640) form a receiving space to accommodate the sealing end cap (450); The length of the third receiving section (640) is greater than the length of the first receiving section (620), and the control section (650) is located at the end of the first receiving section (620) to drive the sealing end cap (450) to rotate when the rotating shaft section (610) rotates.

8. The adjustable-focus monochromatic laser interferometry endpoint detection device according to claim 1, characterized in that, The bottom end of the rotating component (220) is provided with a locking component (221); the top end of the fixing component (210) is provided with a first locking hole (211) and a second locking hole (212), the included angle between the first locking hole (211) and the second locking hole (212) is 45°; and both the first locking hole (211) and the second locking hole (212) are used to pass through the locking component (221); When the locking member (221) is located in the first locking hole (211), the control member (600) is placed on the edge of the sealing end cap (450); when the locking member (221) moves from the first locking hole (211) to the second locking hole (212), the control member (600) rotates by the corresponding angle and opens the sealing end cap (450).

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