End point detection device for high-precision ultraviolet short wave band

Abstract

The utility model provides a high-precision ultraviolet short-wave-band end point detection device which is used for detecting optical signals generated in a machine chamber in the etching and thin film process. The signal collecting module and the processing module are connected through a signal line; the signal collection module comprises a probe and an optical fiber, is arranged on one side of the machine chamber and is used for acquiring an optical signal emitted in the machine chamber in an etching process and transmitting the optical signal to the processing module; the processing module comprises an optical module and a CMOS detector, and is used for processing the optical signal and outputting a light intensity curve through an upper computer. The beneficial effects of the utility model are that specific ultraviolet short-wave band light is preliminarily screened, light signals are accurately extracted and processed through a self-designed light path, and the end point detection accuracy is improved through an end point detection method; the utility model has full aperture ratio adaptability and is suitable for etching of various ultraviolet short wave bands and thin film technology application.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor etching, in particular to a high-precision ultraviolet short-wave etching or thin film endpoint detection device. Background Art

[0002] At present, the detection technology for single-atom-level processes of large-scale integrated circuits is the core element of integrated circuit manufacturing processes, and size miniaturization and three-dimensional structure are the main characteristics of the evolution of manufacturing processes. Accordingly, the continuous reduction of feature sizes has put forward higher and higher requirements on the accuracy of process equipment, especially the control of etching or thin film endpoint detection processes needs to reach the atomic level; and the three-dimensional structure has caused the gradual increase in the complexity of integrated circuit architecture, and the proportion of high-precision etching or thin film endpoint detection processes has increased, thus placing more and more stringent requirements on the uniformity, low damage, and yield of each process step.

[0003] The currently published Chinese patent CN20205104331.5 discloses a method for controlling the morphology of the contact hole etching opening, which judges the progress of etching by the intensity of the optical signal. However, the glow signal contains light waves of multiple different bands, which affects the accuracy of detecting the progress of etching and easily leads to over-etching or incomplete etching. Utility Model Content

[0004] The utility model aims to provide a high-precision endpoint detection device in the ultraviolet short-wave band for effectively and accurately detecting the endpoint of etching or thin film.

[0005] The utility model provides a high-precision endpoint detection device for ultraviolet short-wave band, which is used to detect the optical signal generated by the etching and thin film process in the machine chamber, including: a signal collection module and a processing module, the signal collection module and the processing module are connected by a signal line; the signal collection module includes a probe and an optical fiber, which is arranged on one side of the machine chamber to obtain the optical signal emitted during the etching process in the machine chamber, and transmit the optical signal to the processing module; the processing module includes an optical module and a CMOS detector, which is used to process the optical signal and output the light intensity curve through the host computer. The beneficial effects of the utility model are: preliminary screening of specific ultraviolet short-wave band light through a self-designed optical path to accurately extract and process the optical signal, and the endpoint detection accuracy is improved through the endpoint detection method. The utility model has full aperture rate adaptability and is suitable for etching and thin film process applications in a variety of ultraviolet short-wave bands.

[0006] The present application proposes a high-precision endpoint detection device in the ultraviolet short-wave band, which is used to detect the optical signal generated by the etching process in the machine chamber, including: a signal collection module and a processing module, and the signal collection module and the processing module are connected by a signal line; the signal collection module includes a probe and an optical fiber, which is arranged on one side of the machine chamber to obtain the optical signal emitted during the etching process in the machine chamber, and transmit the optical signal to the processing module; the processing module includes an optical module and a CMOS detector, which is used to process the optical signal and output a light intensity signal curve through a host computer.

[0007] In some specific embodiments, the probe collects optical signals facing the observation window on the side of the machine chamber, the optical fiber has a diameter of 200-500 μm, and the tail end of the optical fiber is connected to the device body through an SMA interface to transmit the acquired optical signal to the processing module.

[0008] In some specific embodiments, the optical module is sequentially configured to include a slit, an aperture, an attenuation lens, a reflector, a focusing lens, a filter, and a cylindrical mirror.

[0009] In some specific embodiments, the attenuation lens is a UV fused silica plane mirror with a diameter of 12.7 mm and a central wavelength of 340 nm.

[0010] The present application proposes a high-precision endpoint detection method in the ultraviolet short-wave band, based on the detection device described in the above embodiment, comprising the following steps:

[0011] Step 1, the signal collection module collects the optical signal emitted during the etching or thin film process in the chamber of the machine;

[0012] Step 2, screening the optical signal through the attenuation lens, enhancing the ultraviolet short-wave band corresponding to the type of plasma to be detected, and cutting off stray light in other bands;

[0013] Step 3, the processing module processes the optical signal and displays the light intensity curve through the host computer;

[0014] Step 4, determine the etching or film endpoint by calculating the change of light intensity in the 2ms time window.

[0015] In some specific embodiments, the etching or thin film process in the chamber of the tool is any one of TSV bosch, WAC, radical TiN, Poly Si and SiARC.

[0016] In some specific embodiments, the etching or thin film process opening ratio in the chamber of the tool is in the range of 0.1%-100%.

[0017] Specifically, the opening ratio of the etched holes that can be detected is 0.1%-100%. "The opening ratio of the etched holes is 0.1%-100%" refers to a range of descriptions of the proportion of the opening size of the etched structure (such as thin film, material layer, etc.) under different process conditions during the semiconductor manufacturing process, especially when performing high-precision endpoint detection in the ultraviolet short-wave band. "Opening ratio" here does not refer to the aspect ratio of a single physical hole, but refers to the ratio of the effective light-transmitting or opening area of ​​the structure (such as through-hole, groove, etc.) formed during the etching process to the area of ​​the entire processed area (such as the mask area on the wafer). This ratio can range from a very small 0.1% to a fully open 100%, which means that it can cover a variety of situations from extremely fine openings to complete removal of materials over a large area.

[0018] In some specific embodiments, the plasma species for enhanced detection corresponds to the ultraviolet short-wave band range of 292-387 nm.

[0019] Specifically, the detection range of the ultraviolet short-wave band is 292-387nm. This band range is specially selected and is more difficult to detect than the ultraviolet medium and long bands. This range covers the characteristic wavelengths of plasma light emission during the process. Plasma emits ultraviolet rays of specific wavelengths during the etching process, and the spectral characteristics of these ultraviolet rays are closely related to the etching layer material and process conditions. Selecting the 292-387nm band can effectively capture these characteristic signals, thereby realizing real-time monitoring of the etching process. By detecting the changes in light intensity within this band, the host computer algorithm can very accurately determine the etching or film endpoint. It usually indicates that the material layer has been completely removed or has reached a preset etching depth, effectively preventing incomplete etching or over-etching, which is crucial to ensuring the precise manufacturing of semiconductor devices. The selection of the 292-387nm ultraviolet short-wave band range enables the detection device to adapt to the stringent monitoring requirements of a variety of different processes, and has wide applicability and flexibility.

[0020] In some specific embodiments, the processing module processes the optical signal, including a wavelength resolution accuracy range of the processed ultraviolet short-wave target optical signal of ±0.8 nm.

[0021] Specifically, the detection range is ±0.8nm signal value, which avoids measurement deviation caused by statistical errors and fluctuations. This range is related to the resolution of the device of the utility model. The higher the resolution of the device during detection, the more obvious the ability to distinguish ultraviolet short-wave light signals can be for characteristic peaks with close wavelengths while ensuring measurement accuracy and stability.

[0022] In some specific embodiments, the etching or film endpoint is determined by calculating the change of light intensity in the 2ms time window. The etching or film endpoint is determined when the ending light intensity at the end of the 2ms time window rises or falls by 10%-60% relative to the starting light intensity.

[0023] The beneficial effects of the present invention are:

[0024] (1) Preliminary screening of light: The target band 292-387nm ultraviolet light is screened through the attenuation lens, which has strong anti-interference ability and can accurately screen and optimize the light from the measured target band;

[0025] (2) High recognition: The self-designed optical path achieves high-precision endpoint detection with a resolution range of ±0.8nm, which has high optical recognition accuracy;

[0026] (3) Efficient endpoint detection method: The device of the present invention accurately calculates and processes light intensity data to determine the etching or film endpoint, effectively preventing over-etching or incomplete etching and accurately controlling the film growth thickness;

[0027] (4) Full aperture ratio applicability: It can be applied to the aperture ratio range of 0.1%-100%, has extremely low aperture ratio adaptability, and can be used in extreme process environments;

[0028] (5) UV short-wave process application: It can be applied to a variety of UV short-wave etching or thin film processes, including TSV bosch, WAC, free radical TiN, Poly Si and SiARC. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a diagram of the application scenario of the device of the utility model in the etching process of the chamber of the target process machine;

[0030] Figure 2 This is a structural diagram of the device of the utility model;

[0031] Figure 3 It is a structural block diagram of the processing module of the device of the utility model;

[0032] Figure 4 This is a schematic diagram of the application principle of the device of the utility model in the etching process;

[0033] Figure 5 The TSV bosch process curve and etching endpoint capture diagram of the utility model in Example 1;

[0034] Figure 6 It is the WAC process curve and etching endpoint capture diagram of the utility model in Example 2;

[0035] Figure 7 The free radical TiN process curve and film endpoint capture diagram of the utility model in Example 3;

[0036] Figure 8 The Poly Si process curve and film endpoint capture diagram of the utility model in Example 4;

[0037] Fig. 9 This is the SiARC process curve and film endpoint capture diagram of the utility model in Example 5.

[0038] Description of reference numerals:

[0039] 1. Signal collection module; 11. Probe; 12. Optical fiber; 2. Processing module; 21. Optical module; 211. Slit; 212. Aperture; 213. Attenuation lens; 214. Reflector; 215. Grating; 216. Focusing lens; 217. Filter; 218. Cylindrical mirror; 22. CMOS detector; 3. Display module; 31. Display unit; 4. Device housing; 5. Machine chamber; 51. Optical signal; 52. Photoresist passivation layer; 53. Etching channel depth. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model. Unless otherwise defined, the technical terms or scientific terms used herein should be understood by people with general skills in the field to which the utility model belongs. "Including" and similar words used in this article mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0041] Embodiment 1, combination Figure 1-4A high-precision endpoint detection device for ultraviolet short-wave band is used to detect the optical signal generated by the etching or thin film process in the machine chamber, including: a signal collection module and a processing module, the signal collection module and the processing module are connected by a signal line; the signal collection module includes a probe and an optical fiber, which is arranged on one side of the machine chamber to obtain the optical signal emitted during the etching process in the machine chamber, and transmit the optical signal to the processing module, wherein the optical module includes an attenuation lens, through which the optical signal is screened, the ultraviolet short-wave band corresponding to the required detection plasma type is enhanced, and stray light in other bands is cut off; the processing module includes an optical module and a CMOS detector, which is used to process the optical signal and output the light intensity curve through the host computer, and judge the etching or thin film endpoint by judging the range of light intensity change at a specific time.

[0042] Specifically, the processing module 2 includes an optical module 21; one end of the optical module 21 is communicatively connected to the signal collecting module 1, and the optical module 21 is used to receive an optical signal and filter out a specific wavelength band from the optical signal.

[0043] Specifically, the optical module 21 includes a grating 215 for sequentially reflecting light in the 292-387 wavelength band at different positions.

[0044] Specifically, the grating 215 may be a diffraction grating 215, which can disperse light according to its wavelength. When light passes through the grating 215, light of different wavelengths will be diffracted at different angles, thereby achieving wavelength separation.

[0045] Specifically, the optical module 21 includes a slit 211 , an aperture 212 , an attenuation lens 213 , a reflector 214 , a grating 215 , a focusing lens 216 , a filter 217 , and a cylindrical mirror 218 , which are arranged in sequence.

[0046] Specifically, each component in the optical module 21 plays a key role in the high-precision endpoint detection device in the ultraviolet short-wave band, and the specific functions are as follows:

[0047] Slit 211: The function of slit 211 is to limit the width of the incident light so that only light along a specific direction can pass through, which is crucial for improving spectral resolution. It helps produce a spectral pattern of alternating light and dark, namely the diffraction spectrum, which is the basis for subsequent spectrometry.

[0048] Aperture 212: Aperture 212 is used to block stray light and constrain the beam size, thereby improving the signal-to-noise ratio. It helps to reduce unnecessary background light interference and ensure the accuracy of analysis.

[0049] Focusing mirror 216: Focusing mirror 216 is located after grating 215. Its function is to converge the light beam dispersed by grating 215 to form a focal plane. This process is necessary to accurately map light of different wavelengths onto the detector to ensure that the spatial distribution of spectral information can be correctly collected.

[0050] The reflector 214 is used to change the path direction of the light, and can be a plane mirror or a curved mirror. In an optical system, the reflector 214 is often used to fold the light path, save space, or direct the light to a specific position.

[0051] Filters 217 are used to selectively transmit certain wavelengths of light while blocking other wavelengths. This has particular uses in spectroscopy and photography, where it can be used to enhance specific colors or eliminate unwanted background light.

[0052] The cylindrical mirror 218 is a non-spherical lens that focuses light in only one direction. In the optical path, the cylindrical mirror 218 can be used to produce a one-dimensional magnification effect, or to compensate for the aberrations produced by other optical elements, such as controlling the angular distribution of the light beam when making the Chrp grating 215.

[0053] The attenuation lens 213 transmits and enhances the 292-387nm ultraviolet short-wave band, blocks and attenuates the light in other bands, and can accurately detect the ultraviolet short-wave band etching or film end point.

[0054] The attenuation lens is a plane mirror made of ultraviolet fused quartz with a diameter of 12.7 mm and a central wavelength of 340 nm.

[0055] In summary, these components work together to ensure that the optical signal can be effectively separated, focused and transmitted to the CMOS detector 22, thereby achieving high-precision analysis of the spectrum within a specific ultraviolet short-wave band and accurately detecting the etching or thin film endpoint.

[0056] Specifically, the processing module 2 further includes a CMOS detector 22, and the CMOS detector 22 is used to process the intensity change information of the specific waveband into electrical signal data.

[0057] Specifically, the signal collection module 1 includes a probe 11 ; the probe 11 is disposed on the machine chamber 5 , and is used to detect the inside of the machine chamber 5 to obtain the optical signal 51 , and transmit it to the processing module 2 .

[0058] Specifically, the signal collection module 1 further includes an optical fiber 12 ; two ends of the optical fiber 12 are respectively connected to the probe 11 and the processing module 2 for communication, so as to transmit the acquired optical signal to the processing module 2 .

[0059] Specifically, the probe 11 is disposed beside the observation window of the machine chamber 5 .

[0060] Specifically, it is convenient to collect the short-wave ultraviolet rays in the machine chamber 5 .

[0061] Specifically, one end of the optical fiber 12 is communicatively connected to the device housing 4 via an SMA interface.

[0062] Specifically, the SMA interface provides a strong and reliable physical connection method to ensure that the optical fiber 12 is firmly fixed to the device housing 4 to prevent it from falling off or being damaged due to vibration, pulling or external forces.

[0063] Specifically, it also includes a display module 3, which includes a display unit 31 communicatively connected to the processing module and used for displaying the light intensity curve. The display module 3 can be a common display device.

[0064] Specifically, the device further comprises a device housing 4 , on which the display unit 31 , the optical module 21 and the CMOS detector 22 are all arranged.

[0065] Specifically, the probe 11 is a lens group.

[0066] Specifically, the lens group can converge light from different directions through its specific curved surface design, so that the light can be focused and imaged at a predetermined position. This is very important for improving detection accuracy and enhancing target detail recognition. The lens group can collect the required light signals over a large range by eliminating or reducing aberrations (such as spherical aberration, chromatic aberration, etc.).

[0067] Specifically, the size of the optical fiber 12 is 200-500 μm.

[0068] Combination Figure 4 , 53 is the depth of the etched trench, the top of the wafer is a photoresist passivation layer 52, and the optical signal 51 will escape into the entire chamber 5. The device detects the optical signal 51 generated in the trench formed during the etching process.

[0069] Embodiment 2,

[0070] Based on the device provided in Example 1, this example demonstrates the application of a high-precision endpoint detection method in the ultraviolet short-wave band in TSV bosch (through silicon via etching), including the following steps:

[0071] Step 1, the signal collection module 1 collects the optical signal 51 emitted during the etching process in the machine chamber 5;

[0072] Step 2, screening the optical signal through the attenuation lens 213, enhancing the ultraviolet short-wave band corresponding to the type of plasma to be detected, and cutting off stray light in other bands;

[0073] Step 3, the processing module 2 processes the optical signal and displays the light intensity curve through the host computer;

[0074] Step 4, determine the etching or film endpoint by calculating the change of light intensity in the 2ms time window.

[0075] Specifically, the etching process in the chamber of the machine is TSV bosch (through silicon via etching).

[0076] Specifically, the etching process opening rate in the chamber of the machine is 0.1%.

[0077] Specifically, the ultraviolet short-wave band range corresponding to the plasma-CO for enhanced detection is 292nm.

[0078] Specifically, the processing module processes the optical signal, including the wavelength resolution accuracy range of the processed ultraviolet short-wave target optical signal is ±0.8nm.

[0079] The detection range of the device of the utility model is a signal value of ±0.8nm, which avoids measurement deviations caused by statistical errors and fluctuations. This range is related to the resolution of the device of the utility model. When detecting, the device with higher resolution can significantly improve the resolution of the ultraviolet short-wave light signal -CO for characteristic peaks with close wavelengths while ensuring measurement accuracy and stability.

[0080] Specifically, the light intensity value at time t is A, and the light intensity value at time t+2ms is B. The range calculation formula of the proportional value is as follows:

[0081]

[0082] Specifically, when the rising or falling ratio of the ending light intensity relative to the starting light intensity at the end of the 2 ms time window reaches 30%, it is determined as the etching end point.

[0083] Specifically, the minimum threshold of the light intensity signal for determining the etching endpoint is 300.

[0084] Specifically, when the determined light intensity value is less than 300, the etching endpoint is not determined.

[0085] Specifically, the etching endpoint is determined by calculating the change of light intensity in a 2ms time window. When the end light intensity at the end of the 2ms time window increases by 30% relative to the start light intensity, the etching or film endpoint t1 is determined.

[0086] The utility model device processes the plasma-CO 292±0.8nm optical signal collected in the TSV bosch process through a high-precision ultraviolet short-wave end point detection method, and displays the plasma-CO light intensity curve on the host computer as follows: Figure 5 As shown, by searching for the light intensity signal point whose rising ratio accounts for 30% of the set amplitude value within the 2ms time window, the etching endpoint is detected at time t1, which effectively prevents additional damage to the wafer during the production process. The utility model device effectively identifies the spectrum change within the range of ±0.8nm, and uses the precise time control of the host computer algorithm to stop the etching endpoint at time t1, thereby improving the accuracy of endpoint detection. The utility model device also improves the signal strength. The light intensity of the plasma-CO in this embodiment can reach 12000-13000, which is higher than the existing level in the semiconductor industry, and effectively solves the detection accuracy problem in the etching process, especially in the ultraviolet short-wave band. The utility model device realizes the application of the microscopic atomic level scale required for the etching process to be controlled, and can effectively improve the yield of the TSV bosch (silicon through-via etching) process through precise monitoring.

[0087] Embodiment 3,

[0088] Based on the device provided in Example 1, this example demonstrates the application of a high-precision endpoint detection method in the ultraviolet short-wave band in WAC (waferless automated cleaning process), including the following steps:

[0089] Step 1, the signal collection module 1 collects the optical signal 51 emitted during the etching process in the machine chamber 5;

[0090] Step 2, screening the optical signal through the attenuation lens 213, enhancing the ultraviolet short-wave band corresponding to the type of plasma to be detected, and cutting off stray light in other bands;

[0091] Step 3, the processing module 2 processes the optical signal and displays the light intensity curve through the host computer;

[0092] Step 4, determine the etching or film endpoint by calculating the change of light intensity in the 2ms time window.

[0093] Specifically, the etching process in the chamber of the machine is WAC (waferless automatic cleaning process).

[0094] Specifically, the etching process opening rate in the chamber of the machine is 100%.

[0095] Specifically, the ultraviolet short-wave band range corresponding to the plasma-O for enhanced detection is 316nm.

[0096] Specifically, the processing module processes the optical signal, including the wavelength resolution accuracy range of the processed ultraviolet short-wave target optical signal is ±0.8nm.

[0097] The detection range of the device of the utility model is a signal value of ±0.8nm, which avoids measurement deviations caused by statistical errors and fluctuations. This range is related to the resolution of the device of the utility model. The device with higher resolution can significantly improve the resolution of the ultraviolet short-wave band light signal -O for characteristic peaks with close wavelengths while ensuring measurement accuracy and stability.

[0098] Specifically, the light intensity value at time t is A, and the light intensity value at time t+2ms is B. The range calculation formula of the proportional value is as follows:

[0099]

[0100] Specifically, when the rising or falling ratio of the ending light intensity relative to the starting light intensity at the end of the 2 ms time window reaches 30%, it is determined as the etching end point.

[0101] Specifically, the minimum threshold of the light intensity signal for determining the etching endpoint is 300.

[0102] Specifically, when the determined light intensity value is less than 300, the etching endpoint is not determined.

[0103] Specifically, the etching endpoint is determined by calculating the change of light intensity in the 2ms time window. The etching endpoint t2 is determined when the end light intensity at the end of the 2ms time window increases by 30% relative to the start light intensity.

[0104] The utility model device processes the plasma-O 316±0.8nm optical signal collected in the TSV bosch process through a high-precision ultraviolet short-wave end point detection method, and displays the plasma-O light intensity curve on the host computer as follows: Figure 6As shown, by searching for the light intensity signal point whose rising ratio accounts for 30% of the set amplitude value within the 2ms time window, the etching endpoint is detected at time t2, which effectively prevents additional damage to the wafer during the production process. The utility model device effectively identifies the spectrum change within the range of ±0.8nm, and uses the precise time control of the host computer algorithm to stop the etching endpoint at time t2, thereby improving the accuracy of endpoint detection. The utility model device also improves the signal strength. The light intensity of the plasma-O in this embodiment can reach 60000-70000, which is higher than the existing level in the semiconductor industry, and effectively solves the detection accuracy problem in the etching process, especially in the ultraviolet short-wave band. The utility model device realizes the application of the microscopic atomic level scale required for the etching process to be controlled, and can effectively improve the yield of the WAC (waferless automatic cleaning process) process through precise monitoring.

[0105] Embodiment 4,

[0106] Based on the device provided in Example 1, this example demonstrates the application of a high-precision endpoint detection method in the ultraviolet short-wave band in free radical Ti N (free radical titanium nitride), comprising the following steps:

[0107] Step 1, the signal collection module 1 collects the optical signal 51 emitted during the thin film process in the machine chamber 5;

[0108] Step 2, screening the optical signal through the attenuation lens 213, enhancing the ultraviolet short-wave band corresponding to the type of plasma to be detected, and cutting off stray light in other bands;

[0109] Step 3, the processing module 2 processes the optical signal and displays the light intensity curve through the host computer;

[0110] Step 4, determine the etching or film endpoint by calculating the change of light intensity in the 2ms time window.

[0111] Specifically, the etching process in the chamber of the machine is free radical TiN (free radical titanium nitride).

[0112] Specifically, the etching process opening rate in the chamber of the machine is 10%.

[0113] Specifically, the ultraviolet short-wave band range corresponding to the plasma-N2 for enhanced detection is 337nm.

[0114] Specifically, the processing module processes the optical signal, including the wavelength resolution accuracy range of the processed ultraviolet short-wave target optical signal is ±0.8nm.

[0115] The detection range of the device of the utility model is a signal value of ±0.8nm, which avoids measurement deviations caused by statistical errors and fluctuations. This range is related to the resolution of the device of the utility model. The device with higher resolution can significantly improve the resolution of the ultraviolet short-wave band light signal -N2 for characteristic peaks with close wavelengths while ensuring measurement accuracy and stability.

[0116] Specifically, the light intensity value at time t is A, and the light intensity value at time t+2ms is B. The range calculation formula of the proportional value is as follows:

[0117]

[0118] Specifically, when the rising or falling ratio of the ending light intensity relative to the starting light intensity at the end of the 2 ms time window reaches 30%, it is determined as the etching end point.

[0119] Specifically, the minimum threshold of the light intensity signal for determining the etching endpoint is 300.

[0120] Specifically, when the determined light intensity value is less than 300, the etching endpoint is not determined.

[0121] Specifically, the etching endpoint is determined by calculating the change of light intensity in the 2ms time window. The end point t3 of the film is determined when the end light intensity at the end of the 2ms time window decreases by 30% relative to the start light intensity.

[0122] The utility model device processes the plasma-N2 337±0.8nm optical signal collected in the free radical TiN (free radical titanium nitride) process through a high-precision ultraviolet short-wave end point detection method, and displays the plasma-N2 light intensity curve on the host computer as follows: Figure 7 As shown, by searching for the light intensity signal point whose drop ratio accounts for 30% of the set amplitude value within the 2ms time window, the etching endpoint is detected at time t3, which effectively prevents additional damage to the wafer during the production process. The utility model device effectively identifies the spectrum change within the range of ±0.8nm, and uses the precise time control of the host computer algorithm to stop the etching endpoint at time t3, thereby improving the accuracy of endpoint detection. The utility model device also improves the signal strength. The light intensity of the plasma-N2 in this embodiment can reach 5000-6000, which is higher than the existing level in the semiconductor industry, and effectively solves the problem of detection accuracy in the thin film growth process, especially involving precise detection in the ultraviolet short-wave band. The utility model device realizes the application of the microscopic atomic level scale required for control of the thin film growth process, and can effectively improve the yield of the free radical TiN (free radical titanium nitride) process through precise monitoring.

[0123] Embodiment 5,

[0124] Based on the device provided in Example 1, this example demonstrates the application of a high-precision endpoint detection method in the short-wave ultraviolet band in Poly Si (polycrystalline silicon process), including the following steps:

[0125] Step 1, the signal collection module 1 collects the optical signal 51 emitted during the thin film process in the machine chamber 5;

[0126] Step 2, screening the optical signal through the attenuation lens 213, enhancing the ultraviolet short-wave band corresponding to the type of plasma to be detected, and cutting off stray light in other bands;

[0127] Step 3, the processing module 2 processes the optical signal and displays the light intensity curve through the host computer;

[0128] Step 4, determine the etching or film endpoint by calculating the change of light intensity in the 2ms time window.

[0129] Specifically, the etching process in the chamber of the machine is Poly Si (polycrystalline silicon process).

[0130] Specifically, the etching process opening rate in the chamber of the machine is 10%.

[0131] Specifically, the ultraviolet short-wave band corresponding to the plasma-NO for enhanced detection is 357 nm.

[0132] Specifically, the processing module processes the optical signal, including the wavelength resolution accuracy range of the processed ultraviolet short-wave target optical signal is ±0.8nm.

[0133] The detection range of the device of the utility model is a signal value of ±0.8nm, which avoids measurement deviations caused by statistical errors and fluctuations. This range is related to the resolution of the device of the utility model. The device with higher resolution can significantly improve the resolution of the ultraviolet short-wave light signal -NO for characteristic peaks with close wavelengths while ensuring measurement accuracy and stability.

[0134] Specifically, the light intensity value at time t is A, and the light intensity value at time t+2ms is B. The range calculation formula of the proportional value is as follows:

[0135]

[0136] Specifically, when the rising or falling ratio of the ending light intensity relative to the starting light intensity at the end of the 2 ms time window is within 30%, it is determined as the etching end point.

[0137] Specifically, the minimum threshold of the light intensity signal for determining the etching endpoint is 300.

[0138] Specifically, when the determined light intensity value is less than 300, the etching endpoint is not determined.

[0139] Specifically, the etching endpoint is determined by calculating the change of light intensity in the 2ms time window. The end point t4 of the film is determined when the end light intensity at the end of the 2ms time window decreases by 30% relative to the start light intensity.

[0140] The utility model device processes the plasma-NO 357±0.8nm optical signal collected in the Poly Si (polycrystalline silicon process) process through a high-precision ultraviolet short-wave end point detection method, and displays the plasma-NO light intensity curve on the host computer as follows: Figure 8 As shown, by searching for the light intensity signal point whose drop ratio accounts for 30% of the set amplitude value within the 2ms time window, the etching endpoint is detected at time t4, which effectively prevents additional damage to the wafer during the production process. The utility model device effectively identifies the spectrum change within the range of ±0.8nm, and uses the precise time control of the host computer algorithm to stop the etching endpoint at time t4, thereby improving the accuracy of endpoint detection. The utility model device also improves the signal strength. The light intensity of the plasma-NO in this embodiment can reach 10000-11000, which is higher than the existing level in the semiconductor industry, and effectively solves the detection accuracy problem in the thin film growth process, especially involving precise detection in the ultraviolet short-wave band. The utility model device realizes the application of the microscopic atomic level scale required for the thin film growth process to be controlled, and can effectively improve the yield of the Poly Si (polycrystalline silicon process) process through precise monitoring.

[0141] Embodiment 6,

[0142] Based on the device provided in Example 1, this example demonstrates the application of a high-precision endpoint detection method in the ultraviolet short-wave band in SiARC (silicon anti-reflective coating), including the following steps:

[0143] Step 1, the signal collection module 1 collects the optical signal 51 emitted during the thin film process in the machine chamber 5;

[0144] Step 2, screening the optical signal through the attenuation lens 213, enhancing the ultraviolet short-wave band corresponding to the type of plasma to be detected, and cutting off stray light in other bands;

[0145] Step 3, the processing module 2 processes the optical signal and displays the light intensity curve through the host computer;

[0146] Step 4, determine the etching or film endpoint by calculating the change of light intensity in the 2ms time window.

[0147] Specifically, the etching process in the chamber of the machine is SiARC (silicon anti-reflective coating).

[0148] Specifically, the etching process opening rate in the chamber of the machine is 10%.

[0149] Specifically, the ultraviolet short-wave band corresponding to the plasma-CN for enhanced detection is 387 nm.

[0150] Specifically, the processing module processes the optical signal, including the wavelength resolution accuracy range of the processed ultraviolet short-wave target optical signal is ±0.8nm.

[0151] The detection range of the device of the utility model is a signal value of ±0.8nm, which avoids measurement deviations caused by statistical errors and fluctuations. This range is related to the resolution of the device of the utility model. The device with higher resolution can significantly improve the resolution of ultraviolet short-wave optical signals -CN for characteristic peaks with close wavelengths while ensuring measurement accuracy and stability.

[0152] Specifically, the light intensity value at time t is A, and the light intensity value at time t+2ms is B. The range calculation formula of the proportional value is as follows:

[0153]

[0154] Specifically, when the rising or falling ratio of the ending light intensity relative to the starting light intensity at the end of the 2 ms time window is within 30%, it is determined as the etching end point.

[0155] Specifically, the minimum threshold of the light intensity signal for determining the etching endpoint is 300.

[0156] Specifically, when the determined light intensity value is less than 300, the etching endpoint is not determined.

[0157] Specifically, the etching endpoint is determined by calculating the change of light intensity in the 2ms time window. The end point t5 of the film is determined when the end light intensity at the end of the 2ms time window decreases by 30% relative to the start light intensity.

[0158] The utility model device processes the plasma-CN 387±0.8nm optical signal collected in the SiARC (silicon anti-reflective coating) process through a high-precision endpoint detection method in the ultraviolet short-wave band, and displays the light intensity curve of the plasma-CO on the host computer as follows: Fig. 9As shown, by searching for the light intensity signal point whose drop ratio accounts for 30% of the set amplitude value within the 2ms time window, the etching endpoint is detected at time t5, which effectively prevents additional damage to the wafer during the production process. The utility model device effectively identifies the spectrum change within the range of ±0.8nm, and uses the precise time control of the host computer algorithm to stop the etching endpoint at time t5, thereby improving the accuracy of endpoint detection. The signal of the utility model device at the second inflection point after the first inflection point is very obvious. This process needs to focus on monitoring the second inflection point; at the same time, the signal strength is also improved. The light intensity of the plasma-CN in this embodiment can reach 11000-12000, which is higher than the existing level in the semiconductor industry, and effectively solves the detection accuracy problem in the thin film growth process, especially involving precise detection in the ultraviolet short-wave band. The utility model device realizes the application of the microscopic atomic level scale required for control of the thin film growth process, and can effectively improve the yield of the SiARC (silicon anti-reflective coating) process through precise monitoring.

[0159] Through the description of the above implementation methods, technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device and unit described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0160] Although the embodiments of the present invention are described in detail above, it is obvious to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as described in the claims. Moreover, the present invention described herein may have other embodiments and may be implemented or realized in a variety of ways.

Claims

1. A high-precision endpoint detection device for short-wave ultraviolet, characterized in that: Used to detect optical signals generated by etching or thin film process in the chamber of the machine, including; A signal collection module and a processing module, wherein the signal collection module and the processing module are connected via a signal line; The signal collection module includes a probe and an optical fiber, which is arranged at one side of the chamber of the machine and used to obtain the optical signal emitted during the etching process in the chamber of the machine and transmit the optical signal to the processing module; The processing module includes an optical module and a CMOS detector, which are used to process optical signals and output light intensity curves through a host computer; wherein the optical module includes an attenuation lens, through which the optical signal is screened, the ultraviolet short-wave band corresponding to the desired plasma type is enhanced, and stray light in other bands is cut off.

2. The detection device according to claim 1, characterized in that: The probe is facing the observation window on the side of the machine chamber to collect optical signals.

3. The detection device according to claim 1, characterized in that: The optical fiber has a diameter of 200-500 μm.

4. The detection device according to claim 1, characterized in that: The tail end of the optical fiber is connected to the device body through the SMA interface to transmit the acquired optical signal to the processing module.

5. The detection device according to claim 1, characterized in that: The optical module is sequentially arranged to include a slit, an aperture, an attenuation lens, a reflector, a focusing lens, a filter and a cylindrical mirror.

6. The detection device according to claim 1, characterized in that: The attenuation lens is a plane mirror made of ultraviolet fused quartz with a diameter of 12.7 mm and a central wavelength of 340 nm.

7. The detection device according to claim 1, characterized in that: The probe is arranged beside the observation window of the chamber of the machine.

8. The detection device according to claim 1, characterized in that: It also includes a display module, which includes a display unit communicatively connected to the processing module and used for displaying a light intensity curve.

9. The detection device according to claim 8, characterized in that: It also includes a device shell, and the display unit, the optical module and the CMOS detector are all arranged on the device shell.

10. The detection device according to claim 1, characterized in that: The probe is a lens group.

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