Narrowband Beyond EUV scintillator based on nanocrystalline boron nitride
Patent Information
- Application Number
- CN202611105384.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-24
- Publication Date
- 2026-10-30
AI Technical Summary
然而，目前用于Beyond EUV光源检测的闪烁体研究尚属空白
本发明提供基于纳米多晶氮化硼的窄带Beyond EUV闪烁体。首先采用化学气相沉积法制备纳米多晶氮化硼闪烁体，然后在纳米多晶氮化硼闪烁体表面镀制由硼单质膜（或含硼化合物膜）、镧系稀土金属单质膜（或含镧系稀土金属化合物膜）与贵金属膜的叠层结构，或者由硼与镧系稀土金属形成的化合物膜和贵金属膜的叠层结构构成的Beyond EUV窄带滤光膜。优化各膜层的配合效果，显著提升Beyond EUV光谱的窄化性能和滤光的稳定性，从而实现对Beyond EUV波段的窄带特定响应。本发明技术方案填补了Beyond EUV波段窄带闪烁体的技术空白，能够满足Beyond EUV光源的窄带检测需求。
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Figure CN123005352A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of beyond ultraviolet lithography technology, specifically relating to a narrowband Beyond EUV scintillator based on nanocrystalline boron nitride. Background Technology
[0002] As semiconductor manufacturing processes continue to approach their physical limits, extreme ultraviolet (EUV) lithography has become the mainstream solution for nodes of 7 nm and below, with its core 13.5 nm wavelength light source generated by high-power laser-driven tin plasma. However, to further improve resolution, reduce the cost per exposure, and adapt to the needs of 2 nm and more advanced processes, researchers are actively seeking "Beyond EUV" (6.X nm, typically 6.7 nm) light source solutions, such as free-electron lasers or laser-driven plasma accelerators. These Beyond EUV light sources theoretically have the potential to extend the minimum linewidth of lithographic patterns to sub-2 nm, but currently still face significant engineering challenges such as light source efficiency, durability, and optical material absorption, representing a cutting-edge competitive direction in semiconductor manufacturing.
[0003] Currently, detection methods for Beyond EUV light sources are still immature. Accurate detection of beam characteristics is crucial to support its research and development. Scintillators, as sensitive materials capable of converting high-energy radiation (such as EUV or X-rays) into visible light, can not only be used to detect the power distribution of the light source but also to directly visualize the beam, thereby intuitively assessing key parameters such as its uniformity, shape, and stability. Nanocrystalline boron nitride has been reported as a radiation-resistant extreme ultraviolet scintillator that can be used to monitor the shape and intensity of high-power extreme ultraviolet beams in real time. However, research on scintillators for Beyond EUV light detection is currently lacking. Applying scintillators to Beyond EUV light detection requires solving the specific wavelength response problem, namely, how to make the scintillator produce a narrowband effective response only in the 6.7 nm Beyond EUV band while suppressing interference from stray light of other wavelengths to achieve accurate detection with a high signal-to-noise ratio. Summary of the Invention
[0004] To address the problems existing in the prior art, this invention provides a narrowband Beyond EUV scintillator based on nanocrystalline boron nitride. First, a nanocrystalline boron nitride scintillator is prepared using chemical vapor deposition. Then, a layered structure consisting of a boron elemental film (or a boron-containing compound film), a lanthanide rare earth metal elemental film (or a lanthanide rare earth metal compound film), and a noble metal film, or a layered structure consisting of a compound film formed by boron and lanthanide rare earth metals and a noble metal film, is deposited on the surface of the nanocrystalline boron nitride scintillator to form a Beyond EUV narrowband filter film. Optimizing the interaction of each film layer significantly improves the Beyond EUV spectral narrowing performance and filtering stability, thereby achieving a narrowband-specific response in the Beyond EUV band. This invention fills the technological gap in Beyond EUV band narrowband scintillators and can meet the narrowband detection requirements of Beyond EUV light sources.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a narrowband Beyond EUV scintillator, comprising a scintillator substrate, wherein a Beyond EUV narrowband filter multilayer film structure is deposited on the scintillator substrate; the narrowband filter multilayer film structure is selected from one of the following: Option 1: A boron elemental film, a lanthanide rare earth metal elemental film, and a noble metal film are stacked sequentially. Option 2: A boron elemental membrane, a lanthanide rare earth metal compound membrane, and a noble metal membrane are stacked sequentially. Option 3: A boron-containing compound film, a lanthanide rare earth metal elemental film, and a noble metal film are stacked sequentially; Option 4: A boron-containing compound film, a lanthanide rare earth metal compound film, and a noble metal film are stacked sequentially; Option 5: A compound film and a noble metal film formed by sequentially stacking boron and lanthanide rare earth metals.
[0006] Furthermore, the Beyond EUV refers to light radiation with a wavelength shorter than 13.5 nm, typically represented by 6.7 nm.
[0007] Furthermore, the material of the scintillator matrix is selected from inorganic scintillators and organic scintillators, including one of yttrium aluminum garnet, diamond, nanocrystalline boron nitride, and halides, preferably nanocrystalline boron nitride.
[0008] Furthermore, the nanocrystalline boron nitride scintillator matrix is prepared by chemical vapor deposition.
[0009] Furthermore, the specific process of the chemical vapor deposition method includes: S1. Use graphite clamps to fix graphite sheet substrates of a specific size, place the fixed substrate in a vertical chemical vapor deposition furnace, evacuate and heat to the reaction temperature of 1500~1600 ℃. S2. Introduce reaction gas into the deposition furnace. The reaction gas is NH3 and BCl3 or NH3 and BF3, with N2 as the carrier gas. The volume ratio of NH3 and BCl3 or NH3 and BF3 is 1.15~1.25:1. S3. After ventilation, maintain the temperature and gas flow rate unchanged, keep warm for 15~25 h, then turn off the power to cool down, so that the nano-polycrystalline boron nitride film cools down to room temperature with the furnace and automatically falls off from the substrate. S4. The nano-polycrystalline boron nitride film is sequentially polished and ultrasonically cleaned to obtain the nano-polycrystalline boron nitride scintillator substrate.
[0010] Furthermore, the boron-containing compound film is boron carbide.
[0011] Furthermore, the lanthanide rare earth metal in the lanthanide rare earth metal elemental film or the lanthanide rare earth metal compound film is any one of lanthanum, cerium, praseodymium, and neodymium.
[0012] Furthermore, the precious metal film is any one of silver film, gold film, platinum film, and palladium film.
[0013] Furthermore, a refractory metal zirconium film or a molybdenum film can be deposited on one side of the noble metal film of the narrow-band filter multilayer film structure as a protective layer.
[0014] Furthermore, the thickness of the boron elemental film or boron-containing compound film is 100-200 nm, the thickness of the lanthanide rare earth metal elemental film or lanthanide rare earth metal compound film is 100-200 nm, the thickness of the compound film formed by boron and lanthanide rare earth metals is 100-200 nm, and the thickness of the noble metal film is 200-300 nm.
[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a narrowband Beyond EUV scintillator based on nanocrystalline boron nitride. First, a nanocrystalline boron nitride scintillator is prepared using chemical vapor deposition. Then, a layered structure consisting of a boron elemental film (or a boron-containing compound film), a lanthanide rare earth metal elemental film (or a lanthanide rare earth metal compound film), and a noble metal film, or a layered structure consisting of a compound film formed by boron and lanthanide rare earth metals and a noble metal film, is deposited on the surface of the nanocrystalline boron nitride scintillator to form a Beyond EUV narrowband filter. Optimizing the interaction of each film layer significantly improves the narrowing performance and filtering stability of the Beyond EUV spectrum, thereby achieving a narrowband-specific response in the Beyond EUV band. This invention fills the technological gap in Beyond EUV band narrowband scintillators and can meet the narrowband detection requirements of Beyond EUV light sources. Attached Figure Description
[0016] Figure 1 The transmittance of the boron (150 nm) / lanthanum (150 nm) / silver (200 nm) stacked film structure in the 5-30 nm wavelength range.
[0017] Figure 2 The transmittance of the lanthanum boride (150 nm) / silver (200 nm) stacked film structure in the 5-30 nm wavelength range is given.
[0018] Figure 3 Photograph of a 2-inch nanocrystalline boron nitride scintillator.
[0019] Figure 4 Photograph of a nanocrystalline boron nitride scintillator for depositing a boron (100 nm) / lanthanum (100 nm) / silver (200 nm) multilayer film.
[0020] Figure 5 Beyond EUV band response curves of nanocrystalline boron nitride scintillators with boron (150 nm) / lanthanum (150 nm) / silver (200 nm) multilayer films. Detailed Implementation
[0021] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0022] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.
[0023] Example: Preparation and testing of nanocrystalline boron nitride scintillators with boron (150 nm) / lanthanum (150 nm) / silver (200 nm) multilayer films. First, the transmittance spectra of the boron (150 nm) / lanthanum (150 nm) / silver (200 nm) multilayer film and the lanthanum boride (150 nm) / silver (200 nm) multilayer film were obtained through theoretical simulation calculations (as shown in Figure 1). Figure 1 and Figure 2 (As shown). Simulation results show that the two stacked film structures exhibit significant transmittance peaks near a wavelength of 6.7 nm, demonstrating significantly higher transmittance characteristics compared to other wavelength bands, thus enabling narrowband filtering.
[0024] Based on the above test results, this embodiment provides a nano-polycrystalline boron nitride scintillator coated with boron / lanthanum / silver multilayer film for accurate detection in the 6.7 nm Beyond EUV band. The specific preparation and structural parameters are as follows: (1) The nano-polycrystalline boron nitride scintillator is prepared by chemical vapor deposition. The specific growth process is as follows: First, a 2-inch graphite substrate is fixed with a graphite clamp and placed in a vertical chemical vapor deposition furnace. The vacuum is evacuated to a background pressure of 10 Pa. The furnace body is heated to a reaction temperature of 1550℃ and kept at that temperature. At the same time, NH3 and BCl3 are introduced at a volume ratio of 1.15:1, where the flow rate of BCl3 is 0.5 L / min and N2 is used as the carrier gas. After the gas is introduced, the pressure inside the furnace is kept at 50 Pa and the temperature is kept at 1550℃. The growth is continued for 20 hours. After the growth is completed, the power is turned off and the furnace is cooled. After growth, the nanocrystalline boron nitride film spontaneously peeled off upon natural cooling. Finally, chemical mechanical polishing yielded a self-supporting nanocrystalline boron nitride scintillator with a diameter of 2 inches and a uniform thickness of 300 μm. Figure 3 As shown.
[0025] (2) A narrow-band filter multilayer film structure was deposited on a nano-polycrystalline boron nitride scintillator using magnetron sputtering. The deposition process of each film layer is as follows: First, a boron film was deposited using a boron target with a purity of 99.95% as the sputtering source in an argon atmosphere. The argon flow rate was set to 28 sccm, the sputtering power to 85 W, the sputtering pressure to 0.6 Pa, and the substrate temperature to 200 ℃. After 1600 s of deposition, a boron film with a thickness of 150 nm was formed.
[0026] Subsequently, a lanthanum film was directly deposited on the boron film surface using a lanthanum target with a purity of 99.99%, an argon flow rate of 26 sccm, a sputtering power of 95 W, a sputtering pressure of 0.45 Pa, a substrate temperature of 200 ℃, and a deposition time of 2400 s, to prepare a lanthanum film with a thickness of 150 nm.
[0027] Finally, a silver film was deposited on the lanthanum film surface. A silver target with a purity of 99.995% was selected, the argon flow rate was 30 sccm, the sputtering power was 120 W, the sputtering pressure was 0.4 Pa, the substrate temperature was reduced to 150 ℃, and after deposition for 3600 s, a silver film with a thickness of 200 nm was obtained. This yielded a nanocrystalline boron nitride scintillator with a boron (150 nm) / lanthanum (150 nm) / silver (200 nm) multilayer film, as shown below. Figure 4 As shown.
[0028] (3) The response of the nanocrystalline boron nitride scintillator coated with boron (150 nm) / lanthanum (150 nm) / silver (200 nm) multilayer film was tested in the Beyond EUV band (e.g. Figure 5 (As shown). Test results show that this scintillator has almost no response outside the Beyond EUV band, and its response bandwidth near the 6.7 nm band is only about 2 nm, exhibiting excellent Beyond EUV narrowband filtering characteristics. Based on these properties, this scintillator can achieve accurate detection in the Beyond EUV band, effectively suppress interference from stray light of other wavelengths, and improve the detection signal-to-noise ratio.
[0029] In summary, the boron / lanthanum / silver stacked film nanocrystalline boron nitride scintillator proposed in this embodiment achieves an ultra-narrowband response of 2 nm in the 6.7 nm band, which has significant engineering application value.
[0030] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.
Claims
1. A narrowband Beyond EUV scintillator, characterized in that, The system includes a scintillator substrate on which a Beyond EUV narrowband filter multilayer film structure is deposited; the narrowband filter multilayer film structure is selected from one of the following options: Option 1: A boron elemental film, a lanthanide rare earth metal elemental film, and a noble metal film are stacked sequentially. Option 2: A boron elemental membrane, a lanthanide rare earth metal compound membrane, and a noble metal membrane are stacked sequentially. Option 3: A boron-containing compound film, a lanthanide rare earth metal elemental film, and a noble metal film are stacked sequentially; Option 4: A boron-containing compound film, a lanthanide rare earth metal compound film, and a noble metal film are stacked sequentially; Option 5: A compound film and a noble metal film formed by sequentially stacking boron and lanthanide rare earth metals.
2. The narrowband Beyond EUV scintillator according to claim 1, characterized in that, The Beyond EUV refers to light radiation with a wavelength shorter than 13.5 nm, typically represented by 6.7 nm.
3. The narrowband Beyond EUV scintillator according to claim 1, characterized in that, The scintillator matrix is any one of yttrium aluminum garnet, diamond, nanocrystalline boron nitride, or halides.
4. The narrowband Beyond EUV scintillator according to claim 3, characterized in that, The nanocrystalline boron nitride scintillator matrix was prepared by chemical vapor deposition.
5. The narrowband Beyond EUV scintillator according to claim 4, characterized in that, The specific process of the chemical vapor deposition method includes: S1. Use graphite clamps to fix graphite sheet substrates of a specific size, place the fixed substrate in a vertical chemical vapor deposition furnace, evacuate and heat to the reaction temperature of 1500~1600 ℃. S2. Introduce reaction gas into the deposition furnace. The reaction gas is NH3 and BCl3 or NH3 and BF3, with N2 as the carrier gas. The volume ratio of NH3 and BCl3 or NH3 and BF3 is 1.15~1.25:
1. S3. After ventilation, maintain the temperature and gas flow rate unchanged, keep warm for 15~25 h, then turn off the power to cool down, so that the nano-polycrystalline boron nitride film cools down to room temperature with the furnace and automatically falls off from the substrate. S4. The nano-polycrystalline boron nitride film is sequentially polished and ultrasonically cleaned to obtain the nano-polycrystalline boron nitride scintillator substrate.
6. The narrowband Beyond EUV scintillator according to claim 1, characterized in that, The boron-containing compound film is boron carbide.
7. The narrowband Beyond EUV scintillator according to claim 1, characterized in that, The lanthanide rare earth metal in the lanthanide rare earth metal elemental film or the lanthanide rare earth metal compound film is any one of lanthanum, cerium, praseodymium, and neodymium.
8. The narrowband Beyond EUV scintillator according to claim 1, characterized in that, The precious metal film is any one of silver film, gold film, platinum film, and palladium film.
9. The narrowband Beyond EUV scintillator according to claim 1, characterized in that, A refractory metal zirconium or molybdenum film is deposited on one side of the noble metal film of the narrow-band filter multilayer film structure as a protective layer.
10. The narrowband Beyond EUV scintillator according to claim 1, characterized in that, The thickness of the boron elemental film or boron-containing compound film is 100~200 nm, the thickness of the lanthanide rare earth metal elemental film or lanthanide rare earth metal compound film is 100~200 nm, the thickness of the compound film formed by boron and lanthanide rare earth metal is 100~200 nm, and the thickness of the noble metal film is 200~300 nm.