An endpoint detection system for a dry etching machine

Abstract

The application discloses a kind of dry etching machine endpoint detection systems, including detector, top shell is positioned and installed in the upper end position of the detector, sealing seat is sealingly positioned between the detector and top shell, optical fiber light hole is opened in the front end side position of the detector, and rotary table is movably arranged in the position of optical fiber light hole in the front end of detector, the filter is arranged on the rotary table, the inside of the detector is opened to box body, and system circuit board and motor are positioned in the inside of box body, and sealing mounting seat is sealingly positioned between the system circuit board and detector.The dry etching machine endpoint detection system disclosed in the application is based on the principle of plasma luminescence spectrum, cooperates with hardware detection and control system, real-time detects reactant concentration, so as to obtain etching reaction endpoint, by using low-cost circuit scheme, this system can be economically and conveniently installed on dry etching equipment in batches, and the purpose of endpoint detection is realized.

Description

Technical Field

[0001] This invention relates to the field of semiconductor-related technologies, and in particular to a dry etching machine endpoint detection system. Background Technology

[0002] A dry etching machine endpoint detection system is a supporting device for detecting the effects of dry etching. In the dry etching process of semiconductor wafer manufacturing, an RF power supply is used to power a plasma ignition module, causing gas ionization to generate plasma to etch away the parts that need to be removed from the wafer. If the RF power is turned off and etching stops before the removed parts are completely stripped, residue will remain. If the removed parts have been completely stripped but the RF power is not turned off in time, allowing plasma to continue to be generated, there is a risk of continuing to etch the underlying structure. How to know when the removed parts have been completely stripped or when the etching reaction should stop is an important problem that needs to be solved. With the continuous development of technology, the manufacturing process requirements for dry etching machine endpoint detection systems are also becoming increasingly stringent.

[0003] First, without any external system, the time required to etch a layer of a certain thickness is roughly estimated by conducting experiments. The fixed RF power-on time is written into the menu program in advance. This estimation method is not accurate enough, and a large number of experiments are required for each material to be etched to obtain parameters, which is time and economically costly.

[0004] Secondly, various probe methods are used to directly contact the plasma, allowing for real-time measurement of parameters such as plasma distribution and energy. This enables real-time monitoring of the etching reaction process. However, this method is problematic because the equipment is expensive and not suitable for mass production. Furthermore, the additional sealing structure required to ensure direct plasma contact presents significant design challenges. Moreover, the lifespan of this method due to direct plasma corrosion remains to be investigated. Therefore, this probe-based approach is only suitable for scientific research.

[0005] The third method involves using a radio frequency emission spectrum analyzer outside the chamber to monitor the radio frequency signals and spectrum changes emitted by the plasma in real time. By using plasma impedance monitoring and radio frequency spectrum analysis technology, the endpoint detection function can be achieved. However, this type of equipment is more expensive, which limits its mass installation in industry. Therefore, we propose an endpoint detection system for dry etching machines. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] To address the shortcomings of existing technologies, this invention provides a dry etching machine endpoint detection system. Based on the principle of plasma emission spectroscopy, and in conjunction with a hardware detection and control system, it detects the reactant concentration in real time to obtain the etching reaction endpoint. By using a low-cost circuit scheme, this system can be economically and conveniently installed in batches on dry etching equipment to achieve the purpose of endpoint detection, effectively solving the problems in the background technology.

[0008] (II) Technical Solution

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a dry etching machine endpoint detection system, comprising a detector, a top shell positioned at the upper end of the detector, a sealing seat sealingly positioned between the detector and the top shell, an optical fiber transmission hole opened at one side of the front end of the detector, and a turntable movably disposed at the position of the optical fiber transmission hole at the front end of the detector, a filter disposed on the turntable, a housing opened inside the detector, and a system circuit board and a motor positioned inside the housing, and a sealing mounting seat sealingly positioned between the system circuit board and the detector.

[0010] As a preferred technical solution of this application, a display panel is positioned on the top shell, the display panel is provided with a display and control buttons, positioning grooves are opened at both ends of the detector, sealing resin is positioned inside the positioning grooves, positioning inserts are installed at both ends of the top shell, and anti-slip pads are positioned on the positioning inserts.

[0011] As a preferred technical solution of this application, the system circuit board is electrically equipped with a shaft detection module, a communication module, a system control module, a signal receiving module, a photoelectric conversion module, and a digital-to-analog conversion module. The shaft detection module is connected to the position of the motor, the signal receiving module is connected to the position of the turntable, the photoelectric conversion module is connected to the signal receiving module, the digital-to-analog conversion module is connected to the photoelectric conversion module, and the system control module is connected to the motor, the shaft detection module, the digital-to-analog conversion module, and the communication module.

[0012] As a preferred technical solution of this application, the detector, top shell, and sealing seat are sealed together, the detector and the optical fiber aperture are integrally formed, the turntable rotates at the front end of the detector, and the turntable is positioned with the filter.

[0013] As a preferred technical solution of this application, the detector and the positioning groove are integrally formed, the positioning groove is positioned with the sealing resin, the top shell and the positioning insert are integrally formed, the positioning insert is positioned with the anti-slip pad, and the bottom of the top shell is positioned with the detector through the positioning insert, the positioning groove and the detector.

[0014] As a preferred technical solution of this application, the motor is electrically connected to the shaft detection module, the signal receiving module is electrically connected to the turntable, the photoelectric conversion module is electrically connected to the signal receiving module, the digital-to-analog conversion module is electrically connected to the photoelectric conversion module, and the system control module is electrically connected to the shaft detection module, the motor, the digital-to-analog conversion module, and the communication module.

[0015] As a preferred technical solution of this application, the system control module pre-stores the emission wavelength spectrum of various common reaction products, determines the reaction products to be measured and their emission wavelengths according to the menu, selects a filter with a suitable wavelength, and drives a motor to rotate the selected filter onto the optical fiber aperture, so that the system control module can only receive the light emitted by the reaction products.

[0016] As a preferred technical solution of this application, the system control module sends a signal to trigger the RF power supply to turn on, plasma generation etching begins, reaction products are generated, and the light emitted by them enters the detection system through the optical fiber aperture. The photoelectric conversion module converts the light signal into a voltage signal, and the system control module measures the voltage signal in real time. When the reaction endpoint is reached, the system control module sends a signal to trigger the RF power supply to turn off, and the etching reaction terminates.

[0017] (III) Beneficial Effects

[0018] Compared with existing technologies, this invention provides a dry etching machine endpoint detection system with the following advantages: This dry etching machine endpoint detection system, based on the principle of plasma emission spectroscopy, combined with a hardware detection and control system, detects the reactant concentration in real time to obtain the etching reaction endpoint. By using a low-cost circuit scheme, this system can be economically and conveniently installed in batches on dry etching equipment to achieve endpoint detection. Using this endpoint detection system, combined with film thickness measurement technology and algorithms, precise control of RF power-on and off is achieved, shortening menu processing time and improving throughput performance. The external machine's control system communicates with the system via a communication module according to the recipe. The system control module for endpoint detection is informed in advance of the wavelength range to be measured. The system control module controls the motor to move the corresponding filter on the turntable to the position of the optical fiber aperture. The shaft detection module will feed back a position signal to the system control module to detect whether the turntable has moved into place. Behind the turntable is a signal receiving module that receives the optical signal. Then, a photoelectric conversion module converts the optical signal into a voltage signal and amplifies it to a suitable voltage. Then, a digital-to-analog conversion module converts the analog voltage into a digital signal and transmits it to the system control module. The turntable is a sealed structure to prevent other light from entering and affecting the measurement. The entire dry etching machine endpoint detection system has a simple structure, is easy to operate, and performs better than traditional methods. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a dry etching machine endpoint detection system according to the present invention.

[0020] Figure 2 This is a schematic diagram of the detector body in the dry etching machine endpoint detection system of the present invention.

[0021] Figure 3 This is a schematic diagram of the detector in the dry etching machine endpoint detection system of the present invention.

[0022] Figure 4 This is a schematic diagram of the structure of the housing in the dry etching machine endpoint detection system of the present invention.

[0023] Figure 5 This is a schematic diagram of the top shell structure in the dry etching machine endpoint detection system of the present invention.

[0024] Figure 6 This is a schematic diagram of the control logic flow chart of a dry etching machine endpoint detection system according to the present invention.

[0025] Figure 7 This is a schematic diagram showing the change in the emission spectrum intensity of a certain reactive substance during the etching process as a function of etching time in the dry etching machine endpoint detection system of the present invention.

[0026] In the diagram: 1. Detector; 2. Top shell; 3. Control button; 4. Display; 5. Display panel; 6. Sealing seat; 7. Fiber optic port; 8. Turntable; 9. Filter; 10. Sealing mounting seat; 11. System circuit board; 12. Motor; 13. Positioning groove; 14. Sealing resin; 15. Box body; 16. Positioning insert; 17. Anti-slip pad; 18. Shaft detection module; 19. Communication module; 20. System control module; 21. Signal receiving module; 22. Photoelectric conversion module; 23. Digital-to-analog conversion module. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. 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. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0028] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, 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 the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] Example 1:

[0031] like Figure 1-7 As shown, a dry etching machine endpoint detection system includes a detector 1, a top shell 2 mounted on the upper end of the detector 1, a sealing seat 6 sealingly positioned between the detector 1 and the top shell 2, an optical fiber passage 7 opened on one side of the front end of the detector 1, and a turntable 8 movably mounted at the position of the optical fiber passage 7 at the front end of the detector 1, with a filter 9 mounted on the turntable 8, a housing 15 opened inside the detector 1, and a system circuit board 11 and a motor 12 positioned inside the housing 15, with a sealing mounting seat 10 sealingly positioned between the system circuit board 11 and the detector 1.

[0032] Furthermore, the detector 1, top shell 2, and sealing seat 6 are sealed together, the detector 1 and the optical fiber through hole 7 are integrally formed, the turntable 8 rotates at the front end of the detector 1, and the turntable 8 is positioned between the filter 9.

[0033] Example 2:

[0034] Based on Example 1, such as Figure 1-7As shown, a dry etching machine endpoint detection system includes a detector 1, a top shell 2 mounted on the upper end of the detector 1, a sealing seat 6 sealingly positioned between the detector 1 and the top shell 2, an optical fiber passage 7 opened on one side of the front end of the detector 1, and a turntable 8 movably mounted at the position of the optical fiber passage 7 at the front end of the detector 1, with a filter 9 mounted on the turntable 8, a housing 15 opened inside the detector 1, and a system circuit board 11 and a motor 12 positioned inside the housing 15, with a sealing mounting seat 10 sealingly positioned between the system circuit board 11 and the detector 1.

[0035] Furthermore, a display panel 5 is positioned on the top shell 2, and a display 4 and control buttons 3 are provided on the display panel 5. Positioning grooves 13 are provided at both ends of the detector 1, and sealing resin 14 is positioned inside the positioning grooves 13. Positioning inserts 16 are positioned and installed at both ends of the top shell 2, and anti-slip pads 17 are positioned on the positioning inserts 16.

[0036] Furthermore, the detector 1 and the positioning groove 13 are integrally formed, the positioning groove 13 is positioned between the sealing resin 14, the top shell 2 and the positioning insert plate 16 are integrally formed, the positioning insert plate 16 is positioned between the anti-slip pad 17, and the bottom of the top shell 2 is positioned between the positioning insert plate 16, the positioning groove 13 and the detector 1.

[0037] Example 3:

[0038] Based on Embodiment 1 and Embodiment 2, as follows Figure 1-7 As shown, a dry etching machine endpoint detection system includes a detector 1, a top shell 2 mounted on the upper end of the detector 1, a sealing seat 6 sealingly positioned between the detector 1 and the top shell 2, an optical fiber passage 7 opened on one side of the front end of the detector 1, and a turntable 8 movably mounted at the position of the optical fiber passage 7 at the front end of the detector 1, with a filter 9 mounted on the turntable 8, a housing 15 opened inside the detector 1, and a system circuit board 11 and a motor 12 positioned inside the housing 15, with a sealing mounting seat 10 sealingly positioned between the system circuit board 11 and the detector 1.

[0039] Furthermore, the system circuit board 11 is electrically equipped with a shaft detection module 18, a communication module 19, a system control module 20, a signal receiving module 21, a photoelectric conversion module 22, and a digital-to-analog conversion module 23. The shaft detection module 18 is connected to the position of the motor 12, the signal receiving module 21 is connected to the position of the turntable 8, the photoelectric conversion module 22 is connected to the signal receiving module 21, the digital-to-analog conversion module 23 is connected to the photoelectric conversion module 22, and the system control module 20 is connected to the motor 12, the shaft detection module 18, the digital-to-analog conversion module 23, and the communication module 19.

[0040] Furthermore, the motor 12 is electrically connected to the shaft detection module 18, the signal receiving module 21 is electrically connected to the turntable 8, the photoelectric conversion module 22 is electrically connected to the signal receiving module 21, the digital-to-analog conversion module 23 is electrically connected to the photoelectric conversion module 22, and the system control module 20 is electrically connected to the shaft detection module 18, the motor 12, the digital-to-analog conversion module 23, and the communication module 19. The external machine's control system, based on the recipe, informs the endpoint detection system control module 20 in advance via the communication module 19 of the wavelength range to be measured. The system control module 20 controls the motor 12 to move the corresponding filter on the turntable 8 to the position of the optical fiber aperture 7. The shaft detection module 18 will feed back the position signal to the system control module 20 to detect whether the turntable 8 has moved into place. Behind the turntable 8 is the signal receiving module 21, which receives the optical signal. Next, the photoelectric conversion module 22 converts the optical signal into a voltage signal and amplifies it to a suitable voltage. Then, the analog-to-digital conversion module 23 converts the analog voltage into a digital signal and transmits it to the system control module 20. The turntable 8 is a sealed structure to prevent other light from entering and affecting the measurement.

[0041] Furthermore, the system control module 20 pre-stores the emission wavelength spectrum of various common reaction products, determines the final reaction product to be measured and its emission wavelength according to the menu, selects a suitable filter 9 with a suitable wavelength, and drives the motor 12 to rotate the selected filter 9 onto the optical fiber aperture 7, so that the system control module 20 can only receive the light emitted by the reaction products.

[0042] Furthermore, the system control module 20 sends a signal to trigger the RF power supply to turn on, plasma generation etching begins, reaction products are generated and the light emitted by them enters the detection system through the optical fiber aperture 7, the photoelectric conversion module 22 converts the light signal into a voltage signal, the system control module 20 measures the voltage signal in real time, and when the reaction endpoint is reached, the system control module 20 sends a signal to trigger the RF power supply to turn off, and the etching reaction terminates.

[0043] Working Principle: This invention includes a detector 1, a top shell 2, a control button 3, a display 4, a display panel 5, a sealing seat 6, an optical fiber transmission hole 7, a turntable 8, a filter 9, a sealing mounting seat 10, a system circuit board 11, a motor 12, a positioning groove 13, sealing resin 14, a housing 15, a positioning insert plate 16, an anti-slip pad 17, a shaft detection module 18, a communication module 19, a system control module 20, a signal receiving module 21, a photoelectric conversion module 22, and a digital-to-analog conversion module 23. This invention is based on the principle of plasma emission spectroscopy, combined with a hardware detection and control system, to detect the reactant concentration in real time, thereby obtaining the etching reaction endpoint. The external machine's control system, according to the rec... IPE informs the system control module 20 of the wavelength range to be measured in advance through the communication module 19. The system control module 20 controls the motor 12 to move the corresponding filter on the turntable 8 to the position of the optical fiber aperture 7. The shaft detection module 18 will feed back the position signal to the system control module 20 to detect whether the turntable 8 has moved into place. Behind the turntable 8 is the signal receiving module 21, which receives the optical signal. Then, the photoelectric conversion module 22 converts the optical signal into a voltage signal and amplifies it to a suitable voltage. Then, the analog-to-digital conversion module 23 converts the analog voltage into a digital signal and transmits it to the system control module 20. The turntable 8 is a sealed structure to prevent other light from entering and affecting the measurement.

[0044] The core of dry etching is the reaction between plasma and the material being etched, generating gaseous reaction products that can be pumped away by a vacuum pump. During this process, different reactants emit different colors of light, which together form the emission spectrum of the etching reaction. The emission spectrum reveals that different reaction products emit light at different wavelengths.

[0045] The entire hardware of the hardware detection and control system is placed in a sealed, opaque box with a light-transmitting hole for connecting to an optical fiber. The light from the reaction products enters the system through the optical fiber. The hardware of the entire system mainly consists of three parts:

[0046] 1. Filter system: It mainly consists of filters of various wavelengths and motors. All filters are fixed on a turntable in sequence. The center of the turntable is connected to the motor shaft. The system drives the motor to rotate the required filter onto the light-passing hole.

[0047] 2. Light intensity to voltage signal conversion circuit: The light filtered by the filter will pass through the light intensity to voltage signal conversion circuit to convert the light signal into a voltage signal for circuit analysis.

[0048] 3. Circuit control system: The system control unit (microcontroller, PLC, or host computer) controls the operation of the entire system.

[0049] The overall control logic is as follows: The system control unit pre-stores the emission wavelength spectrum of various common reaction products. Based on the menu, it determines the final reaction product to be measured and its emission wavelength, selects a suitable filter, and drives a motor to rotate the selected filter onto the light-transmitting aperture, ensuring the system only receives light emitted by the reaction products. The system sends a signal to trigger the RF power supply to turn on, plasma generation and etching begin, and the reaction products are generated. The light emitted by these products enters the detection system through the optical fiber and the light-transmitting aperture. The light intensity-voltage signal conversion circuit converts the light signal into a voltage signal. The circuit control system measures the voltage signal in real time. When the reaction endpoint is reached, the circuit control system sends a signal to trigger the RF power supply to turn off, terminating the etching reaction.

[0050] The endpoint of the reaction is the moment when the light intensity (or voltage) signal drops sharply from a large, stable value to a certain value. To prevent over-etching, this value cannot be too small. The specific endpoint needs to be determined through AI algorithms and experimental data training.

[0051] It should be noted that, in this document, relational terms such as first and second (number one, number two), etc., are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0052] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A dry etching machine endpoint detection system, comprising a detector (1), characterized in that: A top shell (2) is positioned at the upper end of the detector (1), and a sealing seat (6) is sealed between the detector (1) and the top shell (2). An optical fiber through hole (7) is opened on one side of the front end of the detector (1), and a turntable (8) is movably arranged at the position of the optical fiber through hole (7) at the front end of the detector (1). A filter (9) is arranged on the turntable (8). A box (15) is opened on the inner side of the detector (1), and a system circuit board (11) and a motor (12) are positioned on the inner side of the box (15). A sealing mounting seat (10) is sealed between the system circuit board (11) and the detector (1). The top shell (2) is provided with a display panel (5), the display panel (5) is provided with a display (4) and a control button (3), the detector (1) is provided with positioning grooves (13) at both ends, the inner side of the positioning groove (13) is provided with sealing resin (14), the top shell (2) is provided with positioning plates (16) at both ends, and the positioning plates (16) are provided with anti-slip pads (17). The system circuit board (11) is electrically equipped with a shaft detection module (18), a communication module (19), a system control module (20), a signal receiving module (21), a photoelectric conversion module (22), and a digital-to-analog conversion module (23). The shaft detection module (18) is connected to the position of the motor (12), the signal receiving module (21) is connected to the position of the turntable (8), the photoelectric conversion module (22) is connected to the signal receiving module (21), the digital-to-analog conversion module (23) is connected to the photoelectric conversion module (22), and the system control module (20) is connected to the motor (12), the shaft detection module (18), the digital-to-analog conversion module (23), and the communication module (19). The system control module (20) pre-stores the emission wavelength spectrum of each common reaction product, determines the final reaction product and its emission wavelength to be measured according to the menu, selects a suitable filter (9) and drives the motor (12) to rotate the selected filter (9) onto the optical fiber aperture (7) so that the system control module (20) can only receive the light emitted by the reaction product. The system control module (20) sends a signal to trigger the RF power supply to turn on, plasma generation etching begins, reaction products are generated and the light emitted by them enters the detection system through the optical fiber aperture (7), the photoelectric conversion module (22) converts the light signal into a voltage signal, the system control module (20) measures the voltage signal in real time, and when the reaction endpoint is reached, the system control module (20) sends a signal to trigger the RF power supply to turn off, and the etching reaction terminates.

2. The dry etching machine endpoint detection system according to claim 1, characterized in that: The detector (1), top shell (2), and sealing seat (6) are sealed together. The detector (1) and the optical fiber through hole (7) are integrally formed. The turntable (8) rotates at the front end of the detector (1). The turntable (8) is positioned with the filter (9). The turntable (8) is a sealed structure.

3. The dry etching machine endpoint detection system according to claim 2, characterized in that: The detector (1) and the positioning groove (13) are integrally formed. The positioning groove (13) is positioned with the sealing resin (14). The top shell (2) and the positioning plate (16) are integrally formed. The positioning plate (16) is positioned with the anti-slip pad (17). The bottom of the top shell (2) is positioned with the detector (1) through the positioning plate (16), the positioning groove (13).

4. The dry etching machine endpoint detection system according to claim 3, characterized in that: The motor (12) is electrically connected to the shaft detection module (18), the signal receiving module (21) is electrically connected to the turntable (8), the photoelectric conversion module (22) is electrically connected to the signal receiving module (21), the digital-to-analog conversion module (23) is electrically connected to the photoelectric conversion module (22), and the system control module (20) is electrically connected to the shaft detection module (18), the motor (12), the digital-to-analog conversion module (23), and the communication module (19).

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