Wafer edge etching machine and control method thereof

Abstract

The invention discloses a wafer edge etching machine and a control method thereof.The wafer edge etching machine comprises a process chamber, a driving mechanism, a detection device, a bearing device and a shielding disc, the bearing device and the shielding disc are arranged in the process chamber, the bearing device is used for bearing wafers, and the shielding disc and the bearing device are oppositely arranged; the cover plate is used for covering the central area of the wafer and exposing the annular edge with the preset width of the wafer, and the annular edge is distributed around the central area; the detection device is used for detecting whether plasma exists in the gap between the wafer and the shielding disc, the driving mechanism is connected with the detection device and the shielding disc, and the driving mechanism is used for driving at least part of the shielding disc to be close to the wafer under the condition that the plasma exists in the gap until the plasma does not exist in the gap. According to the wafer edge etching machine disclosed by the invention, regulation and control on movement of the shielding disc can be simplified.

Description

Technical Field

[0001] The present application belongs to the technical field of semiconductor process equipment, and specifically relates to a crystal edge etcher and a control method thereof. Background Art

[0002] Edge etching is a method of removing unwanted thin films at the edge of the wafer using plasma etching. At 65nm and below technology nodes, edge etching has attracted more and more attention, mainly because the edge of the wafer has gradually become one of the main factors limiting the yield in integrated circuit manufacturing.

[0003] In order to prevent the crystal edge etching process from etching other areas of the wafer, the crystal edge etcher involved in the related technology is designed with a preset distance between the shielding disk and the wafer. According to Paschen's law, when the distance between the shielding disk and the wafer is less than or equal to the preset distance, the plasma will not enter the gap between the shielding disk and the wafer, and thus will not etch the central area of ​​the wafer except the edge area. However, we know that there are many different process recipes for crystal edge etching, and if the process recipe changes, the corresponding preset distance will change. Designing preset distances corresponding to different process recipes will make the process design of crystal edge etching for semiconductor process equipment too complicated. Summary of the invention

[0004] The invention discloses a crystal edge etcher and a control method thereof, so as to solve the problem that the crystal edge etcher in the related art needs to design different preset distances according to different process recipes, which leads to overly complicated process design of semiconductor process equipment.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] In a first aspect, an embodiment of the present application discloses a crystal edge etcher, the disclosed crystal edge etcher comprises a process chamber, a driving mechanism, a detection device, and a carrying device and a shielding disk arranged in the process chamber, wherein:

[0007] The carrying device is used to carry the wafer, the shielding plate is arranged opposite to the carrying device, and is used to cover the central area of ​​the wafer and expose the annular edge of the wafer with a preset width, and the annular edge is distributed around the central area;

[0008] The detection device is used to detect whether there is plasma in the gap between the wafer and the shielding disk. The driving mechanism is connected to the detection device and the shielding disk respectively. The driving mechanism is used to drive at least part of the shielding disk close to the wafer when the plasma exists in the gap until the plasma no longer exists in the gap.

[0009] In a second aspect, an embodiment of the present application discloses a control method for a crystal edge etcher, wherein the crystal edge etcher is the crystal edge etcher described in the first aspect, and the control method comprises:

[0010] Controlling the detection device to detect whether there is plasma in the gap;

[0011] In a case where the plasma exists in the gap, the driving mechanism is controlled to drive at least a portion of the shielding disk to approach the wafer until the plasma no longer exists in the gap.

[0012] The technical solution adopted by the present invention can achieve the following technical effects:

[0013] The crystal edge etcher disclosed in the embodiment of the present application adds a detection device so that the detection device can directly detect whether there is plasma in the gap between the shielding disk and the central area of ​​the wafer, and when there is plasma in the gap, the shielding disk is directly driven close to the wafer through the driving mechanism to reduce the gap until there is no plasma in the gap. Compared with the traditional method that does not detect whether there is plasma in the gap, but aims to adjust the specific distance between the shielding disk and the wafer, the crystal edge etcher disclosed in the embodiment of the present application can undoubtedly avoid the control method of adjusting the distance between the shielding disk and the wafer to the target distance, and simply adjusts the shielding disk close to the wafer until the detection device cannot detect the presence of plasma in the gap. This control method is simple and easy to implement.

[0014] Moreover, the crystal edge etcher disclosed in the embodiment of the present application does not need to design different preset distances between the shielding plate and the wafer that satisfy Paschen's law according to different process recipes, which is conducive to simplifying the process design. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the crystal edge etcher disclosed in the embodiment of the present application;

[0016] Figure 2 It is a structural schematic diagram of a shielding plate disclosed in an embodiment of the present application;

[0017] Figure 3 It is a schematic diagram of the structure of another shielding plate disclosed in an embodiment of the present application;

[0018] Figure 4 It is a flow chart of a control method of a crystal edge etcher disclosed in an embodiment of the present application;

[0019] Figure 5 It is a flow chart of the control method of the crystal edge etcher disclosed in the embodiment of the present application.

[0020] Description of reference numerals:

[0021] 100-process chamber, 110-guide cylinder,

[0022] 200-driving mechanism, 201-intake passage, 210-first driving unit, 220-second driving unit, 200a-power source, 200b-first connecting member,

[0023] 300-carrying device,

[0024] 400-shielding plate, 401-air hole, 410-first split part, 420-second split part,

[0025] 500-wafer,

[0026] 600-Detection device, 610-Optical emission spectrometer, 620-Langmuir probe, 630-Electron paramagnetic resonance spectrometer,

[0027] L-gap. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] The crystal edge etching opportunities involved in the related art involve a wide variety of process recipes. Different process recipes require different preset distances between the shielding disk and the wafer. In other words, different process recipes result in different preset distances between the shielding disk and the wafer during the crystal edge etching process. The inventor discovered in the process of implementing this application that the related art needs to control the shielding disk to descend according to different process recipes until the preset distance between the shielding disk and the wafer meets the relevant design requirements. In this process, due to the large number of process recipes, the preset distances involved are relatively large, which will cause trouble for the adjustment and control of the shielding disk. In addition, there will be various design errors in the process of designing the preset distance. In other words, even if the distance between the shielding disk and the wafer meets the preset distance required by a certain process recipe, it cannot be guaranteed that the plasma will not penetrate into the gap between the shielding disk and the wafer. Therefore, the inventor discovered that the adjustment in the related art for the purpose of adjusting the shielding disk so that the distance between it and the wafer is less than or equal to the preset distance has a great disadvantage.

[0030] Based on this defect discovered by the inventor, the inventor of the present invention designed this patent application. The technical solutions disclosed in various embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0031] Please refer to Figures 1 to 3 The embodiment of the present application discloses a crystal edge etcher, and the disclosed crystal edge etcher includes a process chamber 100, a driving mechanism 200, a detection device 600, a carrying device 300 and a shielding plate 400.

[0032] The process chamber 100 is the main body of the crystal edge etcher, which is used to form a process space and also provides installation space for other parts of the crystal edge etcher. In the embodiment of the present application, the carrier device 300 and the shielding plate 400 are both arranged in the process chamber 100.

[0033] The carrier device 300 is used to carry the wafer 500. When performing wafer edge etching, the wafer 500 is carried on the carrier device 300. The shielding plate 400 is arranged relative to the carrier device 300. Specifically, the shielding plate 400 is arranged above the carrier device 300. The shielding plate 400 is used to cover the central area of ​​the wafer 500 and expose the annular edge of the preset width of the wafer 500, and the annular edge is distributed around the central area. In this case, the annular edge of the wafer 500 will not be covered by the shielding plate 400, so that it can be etched.

[0034] It should be noted that the embodiment of the present application does not limit the size of the preset width, and those skilled in the art can reasonably design the size of the preset width according to the requirements of the crystal edge etching process.

[0035] In the embodiment of the present application, the shielding plate 400 does not contact the wafer 500 carried by the carrying device 300, that is, there is a gap L between the shielding plate 400 and the central area. The detection device 600 is used to detect whether there is plasma in the gap L between the wafer 500 and the shielding plate 400. Since plasma contains multiple particles, as long as the detection device 600 can detect particles contained in any type of plasma, it means that there is plasma in the gap L. There are multiple tools for detecting whether there is plasma, and the embodiment of the present application does not limit the specific type of the detection device 600.

[0036] The driving mechanism 200 is respectively connected to the detection device 600 and the shielding plate 400. The driving mechanism 200 is used to drive at least part of the shielding plate 400 to approach the wafer 500 when plasma exists in the gap L until there is no plasma in the gap L. When plasma exists in the gap L, according to Paschen's law, reducing the gap L can prevent plasma from entering the gap L.

[0037] The crystal edge etcher disclosed in the embodiment of the present application is provided with a detection device 600, so that the detection device 600 can directly detect whether there is plasma in the gap L between the shielding plate 400 and the central area of ​​the wafer 500, and when there is plasma in the gap L, the shielding plate 400 is directly driven to approach the wafer 500 through the driving mechanism 200 to reduce the gap L until there is no plasma in the gap L. Compared with the traditional method that does not detect whether there is plasma in the gap L, but aims to adjust the specific distance between the shielding plate 400 and the wafer 500, the crystal edge etcher disclosed in the embodiment of the present application can undoubtedly avoid the control method of adjusting the distance between the shielding plate 400 and the wafer 500 to the target distance, and simply adjusts the shielding plate 400 to approach the wafer 500 until the detection device 600 cannot detect the position of plasma in the gap L. This control method is simple and easy to implement.

[0038] Moreover, the crystal edge etcher disclosed in the embodiment of the present application does not need to design different preset distances between the shielding plate and the wafer that satisfy Paschen's law according to different process recipes, which is conducive to simplifying the process design.

[0039] In the embodiment of the present application, the number of the detection device 600 may be one or more, and the embodiment of the present application does not limit the number of the detection device 600. In a more feasible embodiment, there may be more than one detection device 600, and the multiple detection devices 600 may be spaced apart along the circumferential direction of the annular edge. In the case where the multiple detection devices 600 do not detect plasma, it means that there is no plasma in the gap L formed between the shielding disk 400 and the central area. In the case where at least one of the multiple detection devices 600 detects plasma, it means that there is plasma in the gap L between the shielding disk 400 and the central area. In this case, the driving mechanism 200 needs to drive the shielding disk 400 so that at least part of the shielding disk 400 is close to the wafer 500. In this embodiment, by setting up multiple detection devices 600 to detect the presence or absence of plasma at multiple positions, it is undoubtedly possible to improve the detection effect of whether there is plasma in the gap L. In addition, when multiple detection devices 600 are performing detection work, if some detection devices 600 are damaged, the other detection devices 600 can still ensure the detection work, which can undoubtedly improve the stability of the detection work.

[0040] As described above, the driving mechanism 200 drives at least part of the shielding plate 400 to approach the wafer 500. In an optional solution, the shielding plate 400 may be an integral structure, in which case the driving mechanism 200 drives the shielding plate 400 as a whole to approach the wafer 500. Of course, since the shielding plate 400 is an integral structure, only one driving mechanism 200 may be provided, and the driving mechanism 200 can easily realize the driving of the shielding plate 400.

[0041] In another optional solution, the shielding plate 400 can be a split structure, and the shielding plate 400 includes a plurality of first split parts 410 that can move relative to each other, that is, each first split part 410 is independent of the other first split parts 410 to move. Each first split part 410 can be connected to a corresponding detection device 600, and the driving mechanism 200 can include a plurality of first driving units 210 corresponding to the plurality of first split parts 410, and each first driving unit 210 can be installed on the process chamber 100 and connected to the corresponding first split part 410, so as to drive the movement of the corresponding first split part 410 separately. When the detection device 600 detects that there is plasma in the relative area in the gap L, the first driving unit 210 drives the corresponding first split part 410 to approach the wafer 500 for local adjustment.

[0042] In the embodiment of the present application, the first driving unit 210 may be a hydraulic telescopic component, a pneumatic telescopic component, a linear motor driving mechanism, etc. The embodiment of the present application does not limit the specific type and structure of the first driving unit 210.

[0043] In the specific working process, each detection device 600 detects the presence or absence of plasma in the local space between the corresponding first split part 410 and the central area. When plasma exists in the local space of the gap L, the corresponding first drive unit 210 can drive the corresponding first split part 410 to approach the wafer 500 alone until there is no plasma in the local space. Of course, if the detection device 600 does not detect the presence of plasma in the local space, then the corresponding first drive unit 210 does not need to drive the corresponding first split part 410 to approach the wafer 500. It can be seen that in this embodiment, the shielding plate 400 is a split structure, there are multiple detection devices 600, and the drive mechanism 200 is designed to include a plurality of independent first drive units 210. It is undoubtedly possible to independently, specifically and flexibly adjust each first split part 410 to approach the wafer 500, thereby achieving the purpose of flexible adjustment.

[0044] Moreover, during each adjustment process, it is only necessary to let the first driving unit 210 corresponding to the area where plasma exists in the local space drive the first split part 410 corresponding to this area to approach the wafer 500. There is no need for all the first driving units 210 to work, and there is no need to drive all the first split parts 410 (that is, there is no need to adjust the entire baffle plate 400). This can undoubtedly avoid unnecessary adjustments and, of course, is also conducive to reducing energy consumption.

[0045] Specifically, when the driving mechanism 200 includes multiple first driving units 210 and the shielding plate 400 is a split structure, the first driving unit 210 can be driven and connected with the first split part 410 in a one-to-one correspondence. Of course, the first split part 410 can correspond to multiple first driving units 210, and the embodiment of the present application is not limited thereto.

[0046] In the embodiment of the present application, the shape of the first split portion 410 can be various. Figure 2 In an optional solution, the multiple first split parts 410 may all be fan-shaped. The tips of the multiple first split parts 410 are located at the center of the shielding plate 400, and the arc ends of the multiple first split parts 410 are located at the edge of the shielding plate 400. The arc ends of the multiple first split parts 410 may constitute the edge of the shielding plate 400, and the tips of the multiple first split parts 410 may constitute the center of the shielding plate 400. This structure allows the shielding plate 400 to be composed of only the multiple first split parts 410, ensuring the flexibility of the split structure without causing the shielding plate 400 to have too many split components.

[0047] When the shielding plate 400 includes multiple first split parts 410 and the first split parts 410 are fan-shaped, the detection device 600 can be connected to multiple positions of the corresponding first split parts 410. For example, the detection device 600 can be connected to the middle position of the first split part 410, or to a position near the tip of the first split part 410, or to a position near the arc end of the first split part 410, and the embodiments of the present application are not limited thereto.

[0048] In a more feasible solution, each detection device 600 can be connected to the arc end of the corresponding first split part 410 to detect whether plasma exists in the area opposite to the arc end of the first split part 410 in the gap L. Since the arc end of the first split part 410 is closer to the edge of the gap L, once plasma drills into the gap L, it will preferentially enter the edge of the gap L. Therefore, the detection device 600 is connected to the arc end of the corresponding first split part 410, which can achieve timely and fast detection, and ultimately improve the sensitivity of the detection. At the same time, this connection structure can also make the subsequent adjustment of the first split part 410 close to the wafer 500 faster, and ultimately improve the sensitivity of the adjustment.

[0049] Please refer to Figure 3In another feasible solution, the plurality of first split parts 410 are all in arc shape, and the plurality of first split parts 410 are spliced ​​along the circumferential direction of the shielding disk 400 to form an annular structure, and the outer edge of the annular structure constitutes the edge of the shielding disk 400, and the shielding disk 400 also includes a second split part 420, which is circular and located in the circular space surrounded by the plurality of first split parts 410, and the second split part 420 constitutes the center of the shielding disk 400. In this embodiment, the shielding disk 400 includes a first split part 410 and a second split part 420. Once it is found that plasma exists in the area corresponding to the first split part 410 in the gap L, the first split part 410 can be adjusted without adjusting the second split part 420. This structure enables only the first split part 410 constituting the edge of the shielding disk 400 to be adjusted during the adjustment process, which can further improve the flexibility of adjustment.

[0050] Of course, in a further technical solution, the driving mechanism 200 disclosed in the embodiment of the present application may also include a second driving unit 220, which is arranged on the process chamber 100, and the second driving unit 220 is connected to the second split part 420, and the second driving unit 220 is used to drive the second split part 420 close to or away from the wafer 500. In this case, the second driving unit 220 can also drive the second split part 420. Of course, the second driving unit 220 can cooperate with all the first driving units 210 to drive the second split part 420 and all the first split parts 410 respectively, so as to achieve the overall adjustment of the shielding disk 400. It can be seen that the shielding disk 400 of the two split structures disclosed in the embodiment of the present application can be driven by the driving mechanism 200 to achieve the overall approach to the wafer 500, and of course, it can also achieve local independent flexible driving.

[0051] As described above, in the embodiment of the present application, there may be multiple types of the detection device 600, for example, the detection device 600 may be an optical emission spectrometer 610, a Langmuir probe 620, or an electron paramagnetic resonance spectrum detector 630. Of course, in other embodiments, the detection device 600 may include at least one of the optical emission spectrometer 610, the Langmuir probe 620, and the electron paramagnetic resonance spectrum detector 630. These devices can directly detect whether there is plasma in the gap L, and are more suitable for application in the crystal edge etcher disclosed in the embodiment of the present application.

[0052] In a further technical solution, the detection device 600 may include an optical emission spectrometer 610, a Langmuir probe 620, and an electron paramagnetic resonance spectrum detector 630. In this case, the detection device 600 simultaneously uses the optical emission spectrometer 610, the Langmuir probe 620, and the electron paramagnetic resonance spectrum detector 630 to detect whether there is plasma in the gap L, so that the three can play their own detection advantages to improve the accuracy of the detection. At the same time, when one of the optical emission spectrometer 610, the Langmuir probe 620, and the electron paramagnetic resonance spectrum detector 630 fails, the other two can still perform detection and work. It can be seen that the redundant design of the detection device 600 using the optical emission spectrometer 610, the Langmuir probe 620, and the electron paramagnetic resonance spectrum detector 630 at the same time can undoubtedly improve the stability of the detection work.

[0053] When the detection device 600 includes an optical emission spectrometer detector 610, a Langmuir probe 620 and an electron paramagnetic resonance spectrometer detector 630, there are many distribution methods of the optical emission spectrometer detector 610, the Langmuir probe 620 and the electron paramagnetic resonance spectrometer detector 630, which are not limited in the embodiments of the present application.

[0054] It should be noted that plasma includes particles such as ions, electrons, and free radicals. When plasma moves over a long distance, ions and electrons are annihilated first, but free radicals may still exist. The Langmuir probe 620 can detect ions and electrons, but cannot detect free radicals. If the Langmuir probe 620 detects ions or electrons, it means that plasma exists in the gap L. The electron paramagnetic resonance spectrum detector 630 can detect free radicals. As long as free radicals are detected, it means that plasma still exists in the gap L. The optical emission spectrometer detector 610 uses an optical method to measure whether plasma exists as a whole.

[0055] Considering that in the process of plasma drilling into the gap L and moving toward the center of the gap L, ions and electrons are annihilated first, followed by free radicals. Based on this, in an optional solution, the probe of the Langmuir probe 620 and the sampling tube of the electron paramagnetic resonance spectrum detector 630 are distributed in sequence from the edge of the shielding disk 400 to the center of the shielding disk 400. This distribution method can make full use of the different annihilation orders of different types of particles in the plasma during the movement process to arrange the corresponding detection devices in a targeted manner for targeted detection, thereby improving the accuracy of the detection.

[0056] As described above, the optical emission spectrometer 610 performs plasma detection as a whole from an optical perspective. Based on this, in another optional scheme, the optical probe of the optical emission spectrometer 610, the probe of the Langmuir probe 620 and the sampling tube of the electron paramagnetic resonance spectrum detector 630 are distributed in sequence from the edge of the shielding disk 400 toward the center of the shielding disk 400. At this time, the optical emission spectrometer 610 is located at the outermost side, which is conducive to detecting whether there is plasma in the gap L as a whole over a larger range from a more macroscopic perspective.

[0057] The crystal edge etcher disclosed in the embodiment of the present application may be provided with an air inlet channel 201, and the shielding plate 400 is provided with an air blowing hole 401 located at the center thereof. The air inlet channel 201 is connected to the gap L through the air blowing hole 401, and the air inlet channel 201 is used to pass an inert purge gas into the gap L through the air blowing hole 401. In the specific working process, the air inlet channel 201 can introduce an inert purge gas to purge the gap L, so that the bad particles existing in the gap L are blown from the center of the gap L to the surroundings of the wafer 500, and blown away from the surroundings of the wafer 500, thereby avoiding process abnormalities caused by bad particles existing in the gap L. Of course, the inert purge gas is also conducive to the plasma that penetrates into the gap L being blown away from the edge of the gap L.

[0058] In a further technical solution, the air inlet channel 201 may be provided on the driving mechanism 200. In this case, the driving mechanism 200 not only performs a driving function, but also performs a function of forming the air inlet channel 201 for the inert purge gas to pass through.

[0059] As described above, the structure of the driving mechanism 200 can be various. In an optional solution, the driving mechanism 200 may include a power source 200a and a first connecting member 200b, the power source 200a is arranged outside the process chamber 100, the first end of the first connecting member 200b is connected to the power source 200a, the second end of the first connecting member 200b is connected to the shielding plate 400, and the air inlet channel 201 is a hole opened on the first connecting member 200b. This structure forms the air inlet channel 201 by opening the first connecting member 200b, which has the advantages of simple structure and easy implementation. Of course, the air inlet channel 201 can also be an air inlet flexible pipe wrapped around the first connecting member 200b, and the embodiment of the present application does not limit the specific formation method of the air inlet channel 201. In an optional solution, the second driving unit 220 may include a power source 200a and a first connecting member 200b. Of course, in other embodiments, the first driving unit 210 may also include a power source 200a and a first connecting member 200b.

[0060] In the embodiment of the present application, the process chamber 100 may include a guide cylinder 110, the first connector 200b may pass through the guide cylinder 110, and cooperate with the guide cylinder 110 in a guiding manner, and a sealing structure may be provided between the first connector 200b and the guide cylinder 110. Specifically, the sealing structure may be a dynamic sealing structure, such as a magnetic fluid sealing part. The embodiment of the present application does not limit the specific type of the sealing structure.

[0061] Based on the crystal edge etching machine disclosed in the embodiment of this application, please refer to Figure 4 The present application embodiment discloses a control method for a crystal edge etcher, and the disclosed control method includes:

[0062] S11 , controlling the detection device 600 to detect whether there is plasma in the gap L.

[0063] S12 . In the case where plasma exists in the gap L, the driving mechanism 200 is controlled to drive at least a portion of the shielding plate 400 to approach the wafer 500 until there is no plasma in the gap L.

[0064] As described above, the detection device 600 may include an optical emission spectrometer 610, a Langmuir probe 620, and an electron paramagnetic resonance spectrometer 630. The optical probe of the optical emission spectrometer 610, the probe of the Langmuir probe 620, and the sampling tube opening of the electron paramagnetic resonance spectrometer 630 are distributed in sequence from the edge of the shielding disk 400 to the center of the shielding disk 400. In this case, please refer to Figure 5 , in the method described, S11 may include:

[0065] S21 , controlling the Langmuir probe 620 to detect whether there are ions or electrons in the gap L.

[0066] S22 . When the Langmuir probe 620 detects that the ions or electrons do not exist in the gap L, the electron paramagnetic resonance spectrometer 630 is controlled to detect whether free radicals exist in the gap L.

[0067] S23 . When the electron paramagnetic resonance spectrum detector 630 detects that the free radical does not exist in the gap L, determine whether the actual spectrum intensity of the optical emission spectrum detector 610 is greater than the initial spectrum intensity of the preset multiple T.

[0068] The initial spectrum intensity is the spectrum intensity detected by the optical emission spectrum detector 610 when the electron paramagnetic resonance spectrum detector 630 detects that there are no free radicals in the gap L.

[0069] In S21, if the Langmuir probe 620 detects the presence of ions or electrons in the gap L, it means that there is plasma in the gap L. In S22, if the Langmuir probe 620 detects that there are no ions or electrons in the gap L, and the electron paramagnetic resonance spectrum detector 630 detects the presence of free radicals in the gap L, it can also be said that there is plasma in the gap L. Before the crystal edge etching process is performed, S21 and S22 can be implemented. When S21 and S22 are completed and both prove that there is no plasma in the gap L, the crystal edge etching process can be performed. During the subsequent crystal edge etching process, the optical emission spectrometer 610 can be used to control whether plasma enters the gap L during the process continuation stage. In other words, during the crystal edge etching process, the optical emission spectrometer 610 can be used to detect whether plasma exists in the gap L in real time. During the process continuation stage, if the optical emission spectrometer 610 does not detect plasma, the crystal edge etching process continues. If plasma is detected, the drive mechanism 200 is controlled to drive at least part of the shielding disk 400 close to the wafer 500 until the optical emission spectrometer 610 no longer detects plasma. Of course, the detection of the optical emission spectrometer 610 continues until the crystal edge etching process ends.

[0070] Of course, during the process of S21 and S22 , once the presence of plasma is detected in the gap L, the driving mechanism 200 is controlled to drive at least a portion of the shielding plate 400 to approach the wafer 500 until ions, electrons or free radicals can no longer be detected in the gap L.

[0071] For ease of understanding, a process of a crystal edge etching process is listed below. The crystal edge etching process includes the following steps:

[0072] Step 1: Enter the process formula and preset multiple T.

[0073] Step 2: Transfer the wafer 500 via the wafer transfer device.

[0074] Step 3: Control the driving mechanism 200 to drive the shielding plate 400 to lower.

[0075] Step 4: Turn on the optical emission spectrometer 610 , the Langmuir probe 620 and the electron paramagnetic resonance spectrometer 630 .

[0076] Step 5: Start according to the input process formula.

[0077] Step 6: Control the Langmuir probe 620 to detect whether there are ions or electrons in the gap L.

[0078] Step 7: When the Langmuir probe 620 detects the presence of ions or electrons in the gap L, the driving mechanism 200 is controlled to drive the shielding plate 400 to descend, and the step 6 is repeated. Of course, before the driving mechanism 200 drives the shielding plate 400 to descend in this step, if the shielding plate 400 has descended to the limit position, an alarm is sounded to remind the operator to perform maintenance.

[0079] When the Langmuir probe 620 detects that there are no ions or electrons in the gap L, the process proceeds to step eight.

[0080] Step 8: Use the electron paramagnetic resonance spectrometer 630 to detect whether there are free radicals in the gap L.

[0081] Step 9: When the electron paramagnetic resonance spectrometer 630 detects the presence of free radicals in the gap L, the control driving mechanism 200 drives the shielding plate 400 to continue to descend, and the step 8 is repeated. Of course, before the control driving mechanism 200 drives the shielding plate 400 to descend in this step, if the shielding plate 400 has descended to the limit position, an alarm may be sounded to remind the operator to perform maintenance.

[0082] When the electron paramagnetic resonance spectrometer 630 detects that there are no free radicals in the gap L, the process proceeds to step ten.

[0083] Step 10: Record the initial spectral intensity I0 at one or more wavelengths. The present application does not limit the wavelength.

[0084] Step 11: Turn off the Langmuir probe 620 and the electron paramagnetic resonance spectrum detector 630, start the crystal edge etching process, and continue to use the optical emission spectrum detector 610 to detect the actual spectrum intensity I t .

[0085] Step 12: Judgement I t Is it greater than T*I0?

[0086] Step 13: If I t If the value is greater than T*I0, the control driving mechanism 200 drives the shielding plate 400 to continue to descend, and the twelfth step is repeated. Of course, before the control driving mechanism 200 drives the shielding plate 400 to descend in this step, if the shielding plate 400 has descended to the limit position, an alarm can be sounded to remind the operator to perform maintenance.

[0087] Step 14: If I t If it is not greater than T*I0, the crystal edge etching process is continued and the fifteenth step is entered.

[0088] Step 15: Determine whether the time of the crystal edge etching process meets the preset time in the process recipe; if not, re-enter step 12; if so, enter step 16.

[0089] Step 16: Stop the crystal edge etching process.

[0090] Step 17: Control the driving mechanism 200 to raise the shielding plate 400 and transfer the wafer 500.

[0091] Step 18: Perform subsequent treatments such as dry cleaning on the process chamber 100 .

[0092] The above embodiments of the present invention focus on the differences between the various embodiments. As long as the different optimization features of the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0093] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A crystal edge etcher, characterized in that: The invention comprises a process chamber (100), a driving mechanism (200), a detection device (600), and a carrying device (300) and a shielding disk (400) arranged in the process chamber (100), wherein: The carrying device (300) is used to carry a wafer (500), the shielding disk (400) is arranged opposite to the carrying device (300), and is used to cover the central area of ​​the wafer (500) and expose an annular edge of a preset width of the wafer (500), and the annular edge is distributed around the central area; The detection device (600) is used to detect whether plasma exists in the gap (L) between the wafer (500) and the shielding disk (400); the driving mechanism (200) is connected to the detection device (600) and the shielding disk (400), respectively; and the driving mechanism (200) is used to drive at least a portion of the shielding disk (400) to approach the wafer (500) when the plasma exists in the gap (L) until the plasma no longer exists in the gap (L).

2. The crystal edge etcher according to claim 1, characterized in that: There are a plurality of detection devices (600), and the plurality of detection devices (600) are distributed at intervals along the circumferential direction of the annular edge.

3. The crystal edge etcher according to claim 2, characterized in that: The shielding disk (400) is a split structure and comprises a plurality of first split parts (410) capable of relative movement, each of the first split parts (410) being connected to a corresponding detection device (600), the driving mechanism (200) comprising a plurality of first driving units (210) corresponding to the plurality of first split parts (410), the first driving units (210) being arranged on the process chamber (100) and connected to the corresponding first split parts (410); When the detection device (600) detects that the plasma exists in the relative area in the gap (L), the first driving unit (210) drives the corresponding first split part (410) to approach the wafer (500).

4. The crystal edge etcher according to claim 3, characterized in that: The multiple first split parts (410) are all fan-shaped, the tips of the multiple first split parts (410) are located at the center of the shielding plate (400), the arc ends of the multiple first split parts (410) are located at the edge of the shielding plate (400), the arc ends of the multiple first split parts (410) constitute the edge of the shielding plate (400), and the tips of the multiple first split parts (410) constitute the center of the shielding plate (400).

5. The crystal edge etcher according to claim 4, characterized in that: The detection device (600) is connected to the corresponding arc end of the first split portion (410) to detect whether the plasma exists in the area of ​​the gap (L) opposite to the arc end.

6. The crystal edge etcher according to claim 3, characterized in that: The multiple first split parts (410) are all in the shape of an arc, and the multiple first split parts (410) are spliced ​​along the circumferential direction of the shielding plate (400) to form an annular structure. The shielding plate (400) also includes a second split part (420), and the second split part (420) is circular and is located in the circular space surrounded by the multiple first split parts (410), and the second split part (420) forms the center of the shielding plate (400).

7. The crystal edge etcher according to claim 6, characterized in that: The driving mechanism (200) further comprises a second driving unit (220), wherein the second driving unit (220) is arranged on the process chamber (100) and connected to the second split part (420), and the second driving unit (220) is used to drive the second split part (420) to approach or move away from the wafer (500).

8. The crystal edge etcher according to any one of claims 1 to 7, characterized in that: The detection device (600) includes at least one of an optical emission spectrometer (610), a Langmuir probe (620) and an electron paramagnetic resonance spectrometer (630).

9. The crystal edge etcher according to claim 8, characterized in that: The detection device (600) comprises an optical emission spectrometer (610), a Langmuir probe (620) and an electron paramagnetic resonance spectrometer (630), wherein the optical probe of the optical emission spectrometer (610), the probe of the Langmuir probe (620) and the sampling tube opening of the electron paramagnetic resonance spectrometer (630) are distributed in sequence from the edge of the shielding disk (400) to the center of the shielding disk (400).

10. The crystal edge etcher according to claim 1, characterized in that: The crystal edge etcher is provided with an air inlet channel (201), the shielding plate (400) is provided with an air blowing hole (401) located at the center thereof, the air inlet channel (201) is connected with the gap (L) through the air blowing hole (401), and the air inlet channel (201) is used to introduce an inert purge gas into the gap (L) through the air blowing hole (401).

11. The crystal edge etcher according to claim 10, characterized in that: The air inlet passage (201) is opened on the driving mechanism (200).

12. The crystal edge etcher according to claim 11, characterized in that: The driving mechanism (200) comprises a power source (200a) and a first connecting member (200b), wherein the power source (200a) is arranged outside the process chamber (100), a first end of the first connecting member (200b) is connected to the power source (200a), a second end of the first connecting member (200b) is connected to the shielding plate (400), and the air inlet channel (201) is a hole opened in the first connecting member (200b).

13. The crystal edge etcher according to claim 11, characterized in that: The process chamber (100) comprises a guide cylinder (110), the first connecting member (200b) passes through the guide cylinder (110) and is guided and matched with the guide cylinder (110), and a magnetic fluid sealing portion is provided between the first connecting member (200b) and the guide cylinder (110).

14. A control method for a crystal edge etching machine, characterized in that: The crystal edge etcher is the crystal edge etcher according to claim 1, and the control method comprises: controlling the detection device (600) to detect whether plasma exists in the gap (L); In the case where the plasma exists in the gap (L), the driving mechanism (200) is controlled to drive at least a portion of the shielding disk (400) to approach the wafer (500) until the plasma no longer exists in the gap (L).

15. The control method according to claim 14, characterized in that: The detection device (600) comprises an optical emission spectrometer (610), a Langmuir probe (620) and an electron paramagnetic resonance spectrometer (630), wherein the optical probe of the optical emission spectrometer (610), the probe of the Langmuir probe (620) and the sampling tube opening of the electron paramagnetic resonance spectrometer (630) are distributed in sequence from the edge of the shielding disk (400) to the center of the shielding disk (400); wherein: The controlling the detection device (600) to detect whether plasma exists in the gap (L) comprises: controlling the Langmuir probe (620) to detect whether ions or electrons exist in the gap (L); When the Langmuir probe (620) detects that the ions or electrons are not present in the gap (L), controlling the electron paramagnetic resonance spectrometer (630) to detect whether free radicals are present in the gap (L); When the electron paramagnetic resonance spectrum detector (630) detects that the free radical does not exist in the gap (L), it is determined whether the actual spectrum intensity of the optical emission spectrum detector (610) is greater than the initial spectrum intensity, and the initial spectrum intensity is the spectrum intensity detected by the optical emission spectrum detector (610) when the electron paramagnetic resonance spectrum detector (630) detects that the free radical does not exist in the gap (L).

Images