Light ray observation device

Abstract

The application relates to the technical field of microelectronic device manufacturing, in particular to a light observation device. The light observation device of the application is characterized in that a gas inlet of a gas channel is used for connecting a gas source, a gas outlet is used for feeding reaction gas into a reaction chamber of a plasma etching device; a light receiving window is arranged on the gas channel, a light path for light generated by plasma etching is formed between the light receiving window and the gas outlet, the light path is located in the gas channel, and a gas uniformizing shield is used for dispersing the reaction gas and limiting radio frequency. The application uses the gas channel as a light transmission path, combines the gas uniformizing shield, effectively blocks the direct contact of plasma clusters in the reaction chamber with the light receiving window, and continuously flowing reaction gas can also blow the surface of the light receiving window, so that the light receiving window is less likely to be contaminated. When used in cooperation with the plasma etching device, the etching efficiency of the plasma etching device can be improved.

Description

Technical Field

[0001] This application relates to the technical field of microelectronic device manufacturing, and in particular to a light observation device. Background Technology

[0002] Plasma etching technology uses radio frequency excitation to ionize reactive gases (such as CxFy, O2, Ar, etc.) to form plasma. Under the electric field of a capacitively coupled (CCP) or inductively coupled (ICP) cavity, the wafer surface is patterned through physical bombardment and chemical reaction. ICP emission spectroscopy analysis achieves endpoint monitoring through three steps: excitation, dispersion, and detection. The plasma atomizes the sample and excites it to emit light; the spectrometer decomposes the light signal and analyzes the reaction progress by measuring the light intensity.

[0003] In existing technologies, sapphire light-receiving windows are installed on the sidewalls of the etching chamber, transmitting the light signal to the spectrometer via optical fiber. However, after prolonged contact with plasma, thin films or polymers deposit on the inner walls of the sapphire windows, causing light signal attenuation and affecting the accuracy of endpoint determination, necessitating periodic replacement and maintenance. Replacement requires depressurizing the chamber to the atmospheric environment, and if the process involves toxic gases, prolonged nitrogen purging is also required. This is not only cumbersome but also leads to equipment downtime, impacting production efficiency. This structural defect has become a key issue restricting the stability of the etching process and the utilization rate of the equipment. Utility Model Content

[0004] The purpose of this application is to provide a light observation device to improve the service life of the light receiving window and increase etching efficiency.

[0005] To address the aforementioned technical problems, this application provides a light observation device.

[0006] The light observation device of this application includes: A gas channel has an inlet and an outlet. The inlet is used to connect to a gas source for the reaction gas, and the outlet is used to connect to the reaction chamber of a plasma etching apparatus to introduce the reaction gas into the reaction chamber of the plasma etching apparatus. A light receiving window is disposed on the gas channel, and a light path for light generated by plasma etching is formed between the light receiving window and the gas outlet. The light path is located within the gas channel. The gas channel can confine the reactive gas, so that the reactive gas can purge the surface of the light receiving window and prevent the plasma cluster generated by etching from contacting the light receiving window. A gas-uniform shielding component is disposed at the outlet of the gas channel to disperse the reactive gas and restrict plasma clusters and radio frequency. The gas-uniform shielding component is provided with multiple gas-uniform shielding holes.

[0007] Furthermore, the gas equalization shielding hole has an inlet and an outlet, the cross-sectional area of ​​the outlet is smaller than the cross-sectional area of ​​the inlet, the end of the gas equalization shielding hole closer to the gas channel is the inlet, and the end of the gas equalization shielding hole farther from the gas channel is the outlet.

[0008] Furthermore, the gas channel includes a first channel segment and a second channel segment connected to each other. The first channel segment and the second channel segment each have a first end and a second end. The first end of the first channel segment has the gas outlet, and the second end of the second channel segment constitutes the gas inlet. The second end of the first channel segment is equipped with the light receiving window, and the second end of the first channel segment is connected to the first end of the second channel segment.

[0009] Furthermore, the first channel segment and the second channel segment have a set angle between them, the set angle being greater than 80° and less than 100°.

[0010] Furthermore, a first interface is provided at the second end of the first channel segment, and a lens is fixedly installed at the first interface to form the light receiving window.

[0011] Furthermore, the first interface is a flange interface.

[0012] Furthermore, a limiting member for limiting the lens is provided at the first interface, and a fixing member for fixing the limiting member at the first interface is provided on the limiting member.

[0013] Furthermore, the fixing element is a fixing bolt.

[0014] Furthermore, a second interface is provided at the second end of the first channel segment. The second interface is a flange interface and is connected to the first end of the second channel segment.

[0015] Furthermore, it also includes a collector for receiving light generated by plasma etching from the light receiving window.

[0016] Compared with the prior art, this application has at least the following beneficial effects: This application utilizes the gas channel as the light transmission path by placing the light receiving window on the gas channel instead of exposing it directly within the reaction chamber. In this process, on one hand, the directional flow of the reactive gas towards the outlet effectively prevents plasma clusters within the reaction chamber from directly contacting the light receiving window. On the other hand, the continuously flowing reactive gas also purges the surface of the light receiving window, making it less prone to contamination. Combined with a gas-shielding device, this effectively prevents plasma clusters and radio frequency components from entering the gas channel, and prevents the process gas from dissociating into plasma clusters within the gas channel. Therefore, the surface of the light receiving window in this application is less prone to thin film or polymer deposition, resulting in a longer service life and less need for frequent replacement. When used in conjunction with a plasma etching apparatus, it can improve the etching efficiency of the plasma etching apparatus. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of one embodiment of the light observation device of this application; Figure 2 for Figure 1 Top view of the uniform air shielding component in the middle; Figure 3 for Figure 2 A cross-sectional view of the uniform air shielding component in the middle; Figure 4 for Figure 1 A cross-sectional view of another embodiment of the gas-shielding component in the diagram; Figure 5 for Figure 1 Top view of the light observation device in the middle; Figure 6 for Figure 1 A schematic diagram of the first channel section of the gas channel in the light observation device; Figure 7 for Figure 1 A schematic diagram of the second channel section of the gas channel in the light observation device; Figure 8 This is a schematic diagram of the structure of an embodiment of the light observation device of this application when used in conjunction with the reaction chamber of a plasma etching apparatus.

[0018] Figure label: 10. Reaction chamber; 11. Plasma cluster; 20. Gas channel; 21. Gas path; 22. Optical path; 23. First channel segment; 24. Second channel segment; 25. First interface; 26. Second interface; 30. Light receiving window; 31. Limiting component; 32. Fixing component; 40. Uniform gas shielding components; 50. Fiber optic cable; 60. Spectrometer. Detailed Implementation

[0019] The light observation device of this application will now be described with reference to schematic diagrams, which illustrate preferred embodiments of this application. It should be understood that those skilled in the art can modify the application described herein while still achieving its advantageous effects. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit this application.

[0020] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this application and for simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0021] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0022] The present application is described in more detail below by way of example with reference to the accompanying drawings. The advantages and features of the present application will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present application.

[0023] The following is in conjunction with the instruction manual appendix. Figure 1 and attached Figure 8 This paper introduces the light observation device of this application.

[0024] like Figure 1 , Figure 2 , Figure 3 and Figure 5As shown, the light observation device of this application includes a gas channel 20, a light receiving window 30, and a gas uniform shielding component 40. The gas channel 20 has an inlet and an outlet. The inlet is used to connect to a gas source for the reaction gas, and the outlet is used to connect to the reaction chamber 10 of the plasma etching apparatus to introduce the reaction gas into the reaction chamber 10 of the plasma etching apparatus.

[0025] The light receiving window 30 is disposed on the gas channel 20, and an optical path 22 is formed between the light receiving window 30 and the gas outlet for the light generated by plasma etching to pass through. The optical path 22 is located within the gas channel 20. The gas channel 20 can confine the reactive gas, allowing the reactive gas to purge the surface of the light receiving window 30 and preventing the plasma clusters generated by etching from contacting the light receiving window 30. The gas equalization shield 40 is disposed at the gas outlet of the gas channel 20 to disperse the reactive gas and limit the plasma clusters and radio frequency. The gas equalization shield 40 is provided with a plurality of gas equalization shielding holes 41.

[0026] The reaction chamber 10 of the plasma etching apparatus is used for plasma etching, and its sidewalls are provided with through holes. During use, such as... Figure 8 As shown, the outlet of the gas channel 20 of the light observation device of this application is connected to the through hole. On the one hand, it allows the reactive gas to enter the reaction chamber 10 through the gas channel 20 for plasma etching. On the other hand, it allows the light generated by plasma etching to enter the light path 22 formed in the gas channel 20 through the outlet and be received by the light receiving window 30. Thus, the light path 22 and the gas path 21 are made to co-path in this part between the light receiving window 30 and the outlet. The gas equalization shield 40 has a dual function: dispersing the process gas and restricting the radio frequency (RF) gas from entering the gas channel 20. The gas equalization shield 40 is provided with multiple gas equalization shielding holes 41. This design helps to better disperse and homogenize the gas entering the reaction chamber 10, while also effectively blocking the plasma cluster 11 and the RF gas from entering the gas channel 20, preventing the process gas from dissociating into plasma cluster 11 in the gas channel 20. If the gas equalization shield 40 is not provided, on the one hand, the process gas will not be able to enter the reaction chamber 10 evenly, and on the other hand, the blocking effect on the plasma cluster 11 and radio frequency will be weakened, which will increase the risk of the light receiving window 30 being contaminated.

[0027] This application utilizes the gas channel 20 as the light transmission path by placing the light receiving window 30 on the gas channel 20 instead of exposing it directly to the reaction chamber 10. In this process, on the one hand, the directional flow of the reactive gas towards the outlet effectively prevents the plasma cluster 11 in the reaction chamber 10 from directly contacting the light receiving window 30. On the other hand, the continuously flowing reactive gas also purges the surface of the light receiving window 30, making it less prone to contamination. Combined with the gas-shielding shield 40, it effectively prevents the plasma cluster 11 and radio frequency signals from entering the gas channel 20, preventing the process gas from dissociating into plasma clusters 11 within the gas channel 20. Therefore, the surface of the light receiving window 30 in this application is less prone to thin film or polymer deposition, has a longer service life, and does not require frequent replacement. When used in conjunction with a plasma etching apparatus, it can improve the etching efficiency of the plasma etching apparatus.

[0028] The gas channel 20 can be implemented using a pipe made of corrosion-resistant materials such as ceramic, stainless steel, or polytetrafluoroethylene. The light receiving window 30 can be made of high-temperature resistant and light-transmitting materials such as quartz glass or sapphire to observe the light generated during the plasma etching process.

[0029] Specifically, the gas-uniform shielding component 40 can take various forms, such as a perforated plate, a mesh structure, or a honeycomb structure. The number, size, and distribution of the gas-uniform shielding holes 41 can be optimized according to specific requirements. For example, the gas-uniform shielding holes 41 can be evenly distributed on the gas-uniform shielding component 40, or a specific distribution pattern can be adopted to achieve better gas dispersion.

[0030] When used in conjunction with the reaction chamber 10, the gas equalization shield 40 can be disposed on the inner side wall of the reaction chamber 10. In other embodiments, the gas equalization shield 40 can also be disposed on the outer side wall of the reaction chamber 10 and directly connected to the gas channel 20.

[0031] The material selection for the gas uniformity shield 40 is also important. It typically needs to have good corrosion resistance and high temperature resistance to adapt to the plasma etching environment.

[0032] In some embodiments, the ratio of the depth to the diameter of the uniform air shielding hole 41 is greater than or equal to 8.

[0033] Specifically, a longer orifice depth increases the flow path of gas within the gas-uniform shielding orifice 41. As the process gas passes through these elongated orifices, gas molecules collide and mix multiple times within the channels. This extended flow path helps promote thorough mixing and uniform distribution of the gas. For example, if the diameter of the gas-uniform shielding orifice 41 is 0.5 mm, then its depth should be at least 4 mm. This aspect ratio ensures that the gas has sufficient time and space to mix as it passes through the gas-uniform shielding element 40.

[0034] Furthermore, the combination of a smaller aperture and a longer aperture depth can form a waveguide-like structure. This structure provides stronger resistance to radio frequency (RF) signals. RF energy undergoes multiple reflections and attenuations within these elongated channels during propagation, thereby reducing RF energy leakage. If the ratio of the aperture depth to diameter of the gas-shielding hole 41 is small, the resistance to RF signals will be weaker, making it less likely to reduce the risk of contamination of the light-receiving window 30, and also hindering the promotion of thorough gas mixing and uniform distribution.

[0035] Furthermore, this design of the gas-uniform shielding hole 41 can also provide greater resistance to gas flow. This resistance helps to achieve a more uniform gas distribution across the entire surface of the gas-uniform shield 40.

[0036] In a preferred embodiment, the ratio of the depth to the diameter of the gas-uniform shielding hole 41 can be set between 8 and 15. For example, the ratio of the depth to the diameter of the gas-uniform shielding hole 41 is equal to 10. In other embodiments, it can also be 11 or 13. This range can achieve a good balance between gas dispersion effect, radio frequency blocking effect, and manufacturing difficulty. For example, if the diameter of the gas-uniform shielding hole 41 is 0.3 mm, then its depth can be set between 2.4 mm and 4.5 mm.

[0037] In one specific embodiment, the gas-uniform shielding component 40 can be made of a high-temperature resistant and corrosion-resistant material, such as ceramic or special alloy. The thickness of the gas-uniform shielding component 40 can be set to 5 mm, and the diameter to be 50 mm. 100 gas-uniform shielding holes 41 are evenly distributed on the gas-uniform shielding component 40, each hole having a diameter of 0.4 mm and a depth of 3.6 mm, thus the ratio of hole depth to diameter is 9.

[0038] The uniform airflow shielding hole 41 can be fabricated using laser drilling or precision machining to ensure consistent hole diameter and surface finish. The inlet and outlet of the hole can be chamfered to reduce airflow resistance and eddy current generation. Furthermore, the surface of the uniform airflow shield 40 can undergo special treatments, such as plasma spraying, to enhance its corrosion resistance and thermal conductivity.

[0039] In some embodiments, the gas equalization shielding hole 41 has an inlet and an outlet, the cross-sectional area of ​​the outlet is smaller than the cross-sectional area of ​​the inlet, the end of the gas equalization shielding hole 41 closer to the gas channel 20 is the inlet, and the end of the gas equalization shielding hole 41 farther from the gas channel 20 is the outlet.

[0040] Specifically, by making the cross-sectional area of ​​the outlet smaller than that of the inlet, the plasma cluster 11 and radio frequency components are less likely to enter the inlet from the outlet, and consequently less likely to enter the gas uniform shield 40 and the gas channel 20, thereby further reducing the risk of contamination of the light receiving window 30. If this arrangement is not adopted, the probability of the plasma cluster 11 and radio frequency components entering the gas uniform shield 40 and the gas channel 20 will increase, thus increasing the risk of contamination of the light receiving window 30.

[0041] Preferably, such as Figure 4 As shown, the gas equalization shielding hole 41 is a conical hole. Using a conical hole as the gas equalization shielding hole 41 serves two purposes: firstly, it prevents the plasma cluster 11 and radio frequency signals from easily entering the inlet from the outlet; secondly, its conical guiding surface allows a nozzle structure to be formed at the outlet, increasing the flow velocity of the process gas at the outlet and blowing the plasma cluster 11 away from the gas equalization shielding component 40. This makes it less likely for the plasma cluster 11 to approach the gas equalization shielding component 40, thus making it less likely to enter the gas equalization shielding component 40 and the gas channel 20, further reducing the risk of contamination of the light receiving window 30. If a conical hole is not used, a nozzle structure cannot be formed at the outlet of the gas equalization shielding hole 41, the plasma cluster 11 cannot be blown away from the gas equalization shielding component 40, and the risk of contamination of the light receiving window 30 cannot be further reduced.

[0042] In other embodiments, the uniform air shielding hole 41 may also be a stepped hole.

[0043] In some of these embodiments, such as Figure 1 , Figure 6 and Figure 7 As shown, the gas channel 20 includes a first channel segment 23 and a second channel segment 24 connected to each other. The first channel segment 23 and the second channel segment 24 each have a first end and a second end. The first end of the first channel segment 23 has the air outlet, and the second end of the second channel segment 24 constitutes the air inlet. The second end of the first channel segment 23 is equipped with the light receiving window 30, and the second end of the first channel segment 23 is connected to the first end of the second channel segment 24.

[0044] Specifically, the first channel segment 23 and the second channel segment 24 can be connected in various ways, such as flange connection, threaded connection or welding.

[0045] Furthermore, the first channel segment 23 and the second channel segment 24 have a set angle between them, which is greater than 80° and less than 100°, for example, it can be set to about 90 degrees. This makes it easier for the reactive gas to blow through the light receiving window 30 and improve the cleaning effect on the light receiving window 30.

[0046] In practical applications, the size, material, and angle of the tube segments can be adjusted appropriately according to the specific etching process and equipment requirements. For example, for different etching gases, it may be necessary to adjust the length ratio of the first channel segment 23 and the second channel segment 24 to obtain the best observation effect and gas flow performance.

[0047] In some embodiments, a first interface 25 is provided at the second end of the first channel segment 23, and a lens is fixedly mounted at the first interface 25 to form the light receiving window 30. Preferably, the first interface 25 can be a flange interface. In other embodiments, the first interface 25 can also be a threaded interface.

[0048] In some embodiments, a limiting member 31 for limiting the lens is provided at the first interface 25, and a fixing member 32 for fixing the limiting member 31 to the first interface 25 is provided on the limiting member 31.

[0049] Specifically, the limiting member 31 can be a ring-shaped or semi-circular metal sheet, or a snap-fit ​​structure made of plastic. The inner diameter of the limiting member 31 is slightly smaller than the outer diameter of the lens to ensure effective limiting of the lens. The fixing members 32 can be corrosion-resistant bolts, snaps, or other suitable fastening devices, and their number and distribution can be designed according to actual needs. For example, 3-6 fixing members 32 can be evenly distributed around the limiting member 31 to ensure uniform pressure distribution.

[0050] Taking one embodiment as an example, the first interface 25 can be configured as a flange interface, and the limiting member 31 can be provided with four evenly distributed bolt holes for installing fixing bolts to connect the flange interface. The fixing bolts can be M4 stainless steel bolts with a length of 20mm. An O-ring can be added between the limiting member 31 and the first interface 25, and the material can be fluororubber to further enhance the sealing effect.

[0051] In some of these embodiments, such as Figure 6 and Figure 7 As shown, a second interface 26 is also provided on the second end of the first channel segment 23. The second interface 26 is a flange interface and is connected to the first end of the second channel segment 24. The first end of the second channel segment 24 is also a flange interface.

[0052] In a preferred embodiment, the included angle between the first interface 25 and the second interface 26 can be set to 90°. The first interface 25 is coaxial with the through hole of the reaction chamber 10 to facilitate light reception. The second interface 26 can be designed as a standard interface, such as a flange interface, to match the second channel section 24, to ensure good sealing and easy disassembly.

[0053] In some embodiments, the light observation device further includes a collector for receiving light generated by plasma etching from the light receiving window 30.

[0054] Preferably, the collector can be an optical fiber 50, directly connected to the light receiving window 30, for collecting and transmitting the light generated by plasma etching, and transmitting the light to the spectrometer 60. In other embodiments, the collector can also be a photodetector, such as a photodiode, directly installed near the light receiving window 30, for converting optical signals into electrical signals.

[0055] There are several options for connecting the collector to the light receiving window 30. One option is a direct bonding method, where the fiber optic cable 50 or photodetector is attached tightly to the outside of the light receiving window 30. Alternatively, a small optical system, such as a focusing lens, can be placed between the light receiving window 30 and the collector to improve light collection efficiency.

[0056] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if these modifications and variations of this application fall within the scope of the equivalent technology of this application, this application also intends to include these modifications and variations.

Claims

1. A light observation device, characterized in that, include: A gas channel has an inlet and an outlet. The inlet is used to connect to a gas source for the reaction gas, and the outlet is used to connect to the reaction chamber of a plasma etching apparatus to introduce the reaction gas into the reaction chamber of the plasma etching apparatus. A light receiving window is disposed on the gas channel, and a light path for light generated by plasma etching is formed between the light receiving window and the gas outlet. The light path is located within the gas channel. The gas channel can confine the reactive gas, so that the reactive gas can purge the surface of the light receiving window and prevent the plasma cluster generated by etching from contacting the light receiving window. A gas-uniform shielding component is disposed at the outlet of the gas channel to disperse the reactive gas and restrict plasma clusters and radio frequency. The gas-uniform shielding component is provided with multiple gas-uniform shielding holes.

2. The light observation device according to claim 1, characterized in that, The gas equalization shielding hole has an inlet and an outlet. The cross-sectional area of ​​the outlet is smaller than that of the inlet. The end of the gas equalization shielding hole closer to the gas channel is the inlet, and the end of the gas equalization shielding hole farther from the gas channel is the outlet.

3. The light observation device according to claim 1, characterized in that, The gas channel includes a first channel segment and a second channel segment connected to each other. The first channel segment and the second channel segment each have a first end and a second end. The first end of the first channel segment has the air outlet, and the second end of the second channel segment constitutes the air inlet. The second end of the first channel segment is equipped with the light receiving window, and the second end of the first channel segment is connected to the first end of the second channel segment.

4. The light observation device according to claim 3, characterized in that, The first channel segment and the second channel segment have a set angle between them, which is greater than 80° and less than 100°.

5. The light observation device according to claim 3, characterized in that, A first interface is provided at the second end of the first channel segment, and a lens is fixedly installed at the first interface to form the light receiving window.

6. The light observation device according to claim 5, characterized in that, The first interface is a flange interface.

7. The light observation device according to claim 5, characterized in that, The first interface is provided with a limiting member for limiting the lens, and the limiting member is provided with a fixing member for fixing the limiting member at the first interface.

8. The light observation device according to claim 7, characterized in that, The fastener is a fixing bolt.

9. The light observation device according to claim 3, characterized in that, A second interface is also provided at the second end of the first channel segment. The second interface is a flange interface and is connected to the first end of the second channel segment.

10. The light observation device according to claim 2, characterized in that, It also includes a collector for receiving light generated by plasma etching from the light receiving window.

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