Journal of Vacuum Science & Technology A最新文献

{"title":"Core-shell metallic nanotube arrays for highly sensitive surface-enhanced Raman scattering (SERS) detection","authors":"Jinn P. Chu, Yi-Jui Yeh, Chih-Yu Liu, Yi-Xiang Yang, Alfreda Krisna Altama, Ting-Hao Chang, Wei-Hung Chiang, Pakman Yiu, Kuo-Lun Tung","doi":"10.1116/6.0003055","DOIUrl":"https://doi.org/10.1116/6.0003055","url":null,"abstract":"Here, we demonstrate the application of highly ordered, periodic Ag/Au core-shell triangle nanotube arrays as an ultrasensitive and low-cost surface-enhanced Raman scattering (SERS) substrate for the first time. The arrays of core-shell nanotube, with an outer diameter of 1.5 μm, were fabricated using top-down wafer-scale lithography followed by sequential sputter deposition of Ag and Au. The SERS activity of various combinations of core-shell structures was evaluated. It was found that Ag-core nanotubes overlaid with the Au-shell resulted in the highest Raman intensity, where the enhancement factor for R6G as a probe molecule is determined to be 1.38 × 107. Meanwhile, the limit of detections for R6G and ketoprofen analytes was evaluated to be 10−10 and 10−6 M, respectively. Linear correlations between the SERS signal intensities and logarithmical scale of both analytes in different concentrations were also established, ranging 10−4–10−10 and 10−2–10−6 M for R6G and ketoprofen, respectively. The Raman R6G peak intensity mapping suggests our metal nanotube arrays act as effective plasmonic hotspots and, thus, are useful for SERS sensing applications.","PeriodicalId":17490,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136033516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of mechanical and microstructural properties of sputter-deposited Zr-Ni3Al coatings","authors":"Sunil Kumar Tiwari, Akula Umamaheswara Rao, Archana Singh Kharb, Vipin Chawla, Neha Sardana, Devesh Kumar Avasthi, Amit Kumar Chawla","doi":"10.1116/6.0003022","DOIUrl":"https://doi.org/10.1116/6.0003022","url":null,"abstract":"Zr-doped Ni3Al alloy coatings were deposited on a silicon substrate using DC magnetron cosputtering at a substrate temperature of 400 °C. The transformation of phase, microstructure, and surface topography was investigated using GIXRD, field emission scanning electron microscopy, and atomic force microscopy, respectively. The effect of zirconium (Zr) concentration on the microstructure and mechanical properties of Ni3Al coatings has been discussed. It is observed that the high concentration of Zr in Ni3Al coatings led to the evolution of microcracks that further contributes to increasing the surface roughness of the coatings. Results revealed that the Ni3Al coating without Zr content exhibited the highest hardness of 12.8 GPa. It is also found that with the increase in Zr content in host Ni3Al coatings, the hardness decreases, whereas the contact angle increases. Ni3Al coatings with 40 W Zr enrichment showed a hydrophobic nature with a contact angle of 101°.","PeriodicalId":17490,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135943950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanistic analysis on low temperature thermal atomic layer deposition of nitrides utilizing H2S","authors":"Jinwoo Lee, Soo Hyun Lee, Bonggeun Shong","doi":"10.1116/6.0003041","DOIUrl":"https://doi.org/10.1116/6.0003041","url":null,"abstract":"Atomic layer deposition (ALD) enables the deposition of thin films with excellent step coverage and conformality that are required for nanoscale semiconductor devices. For ALD of nitrides, the high thermal budget required to eliminate impurities in the deposited films is often an issue. Recently, an alternative three-step recipe for thermal ALD of nitrides is reported to simultaneously decrease both the deposition temperature and the impurity contamination, by introducing H2S between chloride precursors and NH3 reactants. In this study, a theoretical analysis is conducted on comparing direct versus three-step alternative reaction paths for thermal ALD of nitrides using density functional theory calculations. The introduction of H2S would enhance the ligand-exchange reaction for nitrides of Al, Ti, and Zr by modifying the reaction scheme to involve a greater number of steps for each lower activation energy required. However, SiN ALD is expected to be hindered by H2S. Our study may be utilized for the development of a new efficient method for ALD of nitride thin films at lower process temperatures.","PeriodicalId":17490,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136112459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ternary Ga–Sn–O and quaternary In–Ga–Sn–O channel based thin film transistors fabricated by plasma-enhanced atomic layer deposition","authors":"Jong Hyeon Won, Hyeonhui Jo, Pil Ju Youn, Bo Keun Park, Taek-Mo Chung, Jeong Hwan Han","doi":"10.1116/6.0003004","DOIUrl":"https://doi.org/10.1116/6.0003004","url":null,"abstract":"Amorphous In–Ga–Sn–O (IGTO), as an n-type amorphous oxide semiconductor, has attracted interest owing to its potential applications to the vertical NAND or 3D DRAM channels as well as in high-mobility thin-film transistors (TFTs) for high-resolution displays. In this study, ternary Ga–Sn–O (GTO) and quaternary IGTO films were deposited through plasma-enhanced atomic layer deposition (PEALD) at 200 °C, using dimethyl(N-ethoxy-2,2-dimethylcarboxylicpropanamide)indium, trimethylgallium, and bis(1-dimethylamino-2-methyl-2-propoxide)tin as the In, Ga, and Sn precursors, respectively. First, GTO films were fabricated through PEALD with varying Ga2O3:SnO2 subcycle ratios. The remarkable evolutions of the microstructure and electrical properties of the PEALD GTO films were observed depending on the Ga/Sn cationic ratio. Subsequently, the growth characteristics of the quaternary PEALD IGTO films were examined by introducing In2O3 subcycles, and the In:Ga:Sn cationic composition was precisely engineered by varying the ratios of In2O3, SnO2, and Ga2O3 subcycles in the IGTO deposition process. Composition-controlled IGTO bottom gate staggered-type TFTs were fabricated, and their electrical performance was evaluated depending on the In:Ga:Sn cationic composition of the IGTO channel layer. The optimized TFT with the In0.38Ga0.32Sn0.30Ox film exhibited a high field-effect mobility of 22.5 cm2/V s, turn-on voltage of −4.4 V, and subthreshold swing of 0.26 V/dec.","PeriodicalId":17490,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136112711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ordered deficient perovskite La2/3TiO3 films grown via molecular beam epitaxy","authors":"Joan Weng, Hyungki Shin, Simon Godin, Mohamed Oudah, Ronny Sutarto, Rebecca Pons, Bruce A. Davidson, Ke Zou","doi":"10.1116/6.0003091","DOIUrl":"https://doi.org/10.1116/6.0003091","url":null,"abstract":"As the parent compound of a promising solid electrolyte material Li3xLa2/3−xTiO3, the perovskite La2/3TiO3 has potential for advancing research on Li-intercalated ionic conductors. Epitaxial La2/3TiO3 films have been grown by molecular beam epitaxy using a growth process consisting of deposition and annealing cycles, with in situ monitoring by electron diffraction. X-ray absorption spectroscopy confirms the tetravalent state of Ti in La2/3TiO3, and the as-grown films are insulating. X-ray diffraction reveals the presence of half-order peaks, indicating a doubling of the pseudocubic perovskite unit cell due to the ordering of La vacancies in alternating A-site layers. These results demonstrate that single-phase, vacancy-ordered epitaxial films of La2/3TiO3 can be stabilized with excellent crystalline and electronic properties over wafer-sized areas, making possible Li-ion intercalation studies in films with well-defined domain boundary properties. Such boundaries are known to profoundly influence Li-ion conduction within the material. Understanding the effects of domain boundaries on Li-ion conduction could lead to improvements in solid-state battery technology and pave the way for the development of more efficient and safer energy storage devices.","PeriodicalId":17490,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136012827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tribological behavior and wear mechanism of nanomultilayer AlCrN/AlTiSiN coatings at elevated temperatures","authors":"Baijun Xiao, Teng Fei Zhang","doi":"10.1116/6.0003019","DOIUrl":"https://doi.org/10.1116/6.0003019","url":null,"abstract":"Wear resistance is a critical property of tool coatings for high-speed machining, which depends on mechanical properties and oxidation resistance of the coatings. Many works have demonstrated that AlTiSiN coating has good mechanical properties. Additionally, AlCrN coating exhibits excellent oxidation resistance. The multilayered structure has proved to improve comprehensive properties of the coatings. Therefore, AlCrN/AlTiSiN multilayer coating has a high potential to be used in machining applications. This paper focuses on the high-temperature tribological behavior of AlCrN/AlTiSiN multilayer coating. The results show that AlCrN/AlTiSiN coating exhibits good to acceptable wear resistance up to 800 °C. Meanwhile, AlCrN/AlTiSiN coating also displays the lowest friction coefficient of ∼0.5 and a wear rate of 1.8 × 10−6 mm3/N m at 800 °C, which is about 58.13% and 64.0% lower than that of AlCrN and AlTiSiN coatings, respectively. The imaging and composition analysis of the high-temperature wear tracks allowed for explaining the differences in wear mechanisms. At 800 °C, a dense thin tribofilm is formed on the surface of AlCrN/AlTiSiN coating, which acts as a glaze layer to impede wear. It provides a strategy for enhancing the wear resistance of monolayer coating in high temperatures, which combines the advantages of both high oxidation resistance of one layer and high hardness of the other layer.","PeriodicalId":17490,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136013007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stannane in extreme ultraviolet lithography and vacuum technology: Synthesis and characterization","authors":"Raquel Garza, Nathan Bartlett, Jameson Crouse, Andrew Herschberg, R. Mohan Sankaran, Md. Amzad Hossain, David N. Ruzic","doi":"10.1116/6.0002980","DOIUrl":"https://doi.org/10.1116/6.0002980","url":null,"abstract":"In extreme ultraviolet (EUV) lithography, tin droplets evaporate and subsequently coat various surfaces including the collector mirrors. To clean off the tin, a hydrogen plasma is often used, but as a result, an unstable by-product, stannane (SnH4) is formed. The physicochemical characteristics of this gas, its formation in a plasma process, and its interaction with various materials have not been explored and understood completely. Here, the electron ionization mass spectrum of SnH4 is presented. All ten natural abundance isotopes were observed experimentally for each fragment, i.e., Sn+, SnH+, SnH2+, and SnH3+. Density functional electronic structure theory was used to calculate the optimized ground state geometries of these gas phase species and their relative stabilities and helped explain the absence of SnH4+ in the observed signals. The density of the liquid, its cracking pattern, and the surface morphology of its deposits were examined. The surface of the deposited tin film resulting from the decomposition and subsequent oxidation was characterized by x-ray photoelectron spectroscopy. The main species found at the surface were metallic tin and tin (II) oxide (SnO). The detailed characterization of stannane should help correctly identify it in EUV lithographic processes and develop approaches in the future to mitigate its decomposition and redeposition on the collector mirrors or vacuum chamber walls.","PeriodicalId":17490,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136352789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation of thin films via cold-rolled/annealed nickel sputtering targets","authors":"Sixie Li, Ming Wen, Chuanjun Wang, Yiqing Wang, Yue Shen","doi":"10.1116/6.0003033","DOIUrl":"https://doi.org/10.1116/6.0003033","url":null,"abstract":"Nickel (Ni) thin films are commonly used in the integrated circuit field. Magnetron sputtering is a common method for thin film deposition, and the sputtering target is the key raw material in the magnetron sputtering process. In this work, cold-rolled and annealed Ni targets were prepared. The microstructures and magnetic properties of the Ni targets were analyzed. Then, Ni films were prepared by direct current magnetron sputtering with the above two Ni targets. The Ni films were characterized by scanning electron microscopy, atomic force microscopy, grazing incidence x-ray diffraction, x-ray reflectivity, and four-probe testing. Finally, the surface morphologies of the targets were compared before and after sputtering, and the relationships between the Ni targets and the Ni films were discussed. The results show that with the same conditions, the annealed Ni target is more efficiently utilized, and the electrical properties of the Ni films are good when the film is macrostructurally smooth and microstructurally compact. This is due to the target texture, magnetic properties, etc.","PeriodicalId":17490,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136353392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase composition of polycrystalline HfNx (0.45 ≤ x ≤ 1.60) and effects of low-energy ion irradiation on microstructure, texture, and physical properties","authors":"Hwan-Seok Seo, Taeyoon Lee, Hyungjun Kim, Ivan Petrov, J. E. Greene","doi":"10.1116/6.0003072","DOIUrl":"https://doi.org/10.1116/6.0003072","url":null,"abstract":"We have investigated the phase composition of HfNx as a function of x and the effects of low-energy ion irradiation on the microstructure and physical properties of polycrystalline layers grown on SiO2 at 350 °C by ultrahigh vacuum reactive dc magnetron sputtering of Hf in mixed N2/Ar discharges. X-ray diffraction and Rutherford backscattering spectrometry results show that the phases obtained in polycrystalline HfNx layers with increasing x are hcp-structure α-Hf:N (x ≲ 0.6); multiphase mixtures consisting of α-Hf, NaCl-structure δ-HfN, rhombohedral ɛ-Hf3N2, and/or ζ-Hf4N3 (0.6 ≲ x ≲ 0.9); δ-HfN single phase (0.9 ≲ x ≲ 1.3); and mixtures of δ-HfN and higher nitrides (x ≳ 1.3). HfNx layers with 0.9 ≲ x ≲ 1.2 grown under mild ion irradiation (incident ion energy Ei ≃ 7 eV and ion-to-Hf flux ratios Ji/JHf = 1−3) are underdense with mixed orientation, low in-plane stress, and rough surface morphology due to limited adatom mobilities resulting in kinetic roughening and atomic shadowing during film growth. However, the use of intense ion irradiation (Ei = 25 eV and Ji/JHf = 4−20) results in HfNx layers, which are fully dense with strongly 111-oriented texture, compressive in-plane stress, and smooth surfaces due to ion irradiation enhanced adatom surface mobilities. In addition, the latter films have lower resistivity and higher hardness. For stoichiometric δ-HfN layers, ρ decreases from 69.7 to 35.2 μΩ cm and H increases from 22.1 to 27.4 GPa, with increasing ion-irradiation intensity. However, for HfNx layers with 1.2 ≲ x ≲ 1.6, the correspondingly higher steady state atomic N surface coverages during deposition alter growth kinetics in favor of 001 texture with a fully dense structure and compressive in-plane stress.","PeriodicalId":17490,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136353242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of duty cycle and nitrogen flow rate on the mechanical properties of (V,Mo)N coatings deposited by high-power pulsed magnetron sputtering","authors":"Yiqun Feng, Tsai-Fu Chung, Chien-Nan Hsiao, Jia-Hong Huang","doi":"10.1116/6.0003006","DOIUrl":"https://doi.org/10.1116/6.0003006","url":null,"abstract":"(V,Mo)N is theoretically predicted to have high hardness and fracture toughness and is a promising material for the application on protective hard coatings. However, the toughness enhancement of (V,Mo)N coatings deposited by dc-unbalanced magnetron sputtering (dc-UBMS) was not as remarkable as expected. The issue could be due to insufficient energy delivery to the plasma species in the deposition process such that nitrogen and metal atoms were not fully reacted and led to the degradation of coating quality. Since high-power pulsed magnetron sputtering (HPPMS) can provide high peak power density, the method was selected to deposit (V,Mo)N coatings in this research. The objective of this study was to investigate the effects of duty cycle and nitrogen flow rate on the microstructure and mechanical properties of (V,Mo)N coatings deposited on Si substrates by HPPMS. Four sets of (V,Mo)N coatings were deposited by HPPMS at different durations with two duty cycles, 5% and 3%, and two nitrogen flow rates, 6.0 and 12.0 SCCM. The results showed that the N/metal ratio was mainly affected by the nitrogen flow rate, ranging from 0.70 to 0.96 with increasing nitrogen flow rate. The lattice parameter of the samples linearly increased with the N/metal ratio. The x-ray diffraction (XRD) patterns revealed that all samples tended to approach (200)-preferred orientation with increasing deposition duration. The glancing incident XRD patterns indicated that the samples deposited at 6 SCCM nitrogen flow rate and 3% duty cycle have multiphases. Transmission electron microscopy analysis confirmed that phase separation from (V,Mo)N to (V-rich,Mo)N and (V,Mo-rich)N occurred in those samples. The hardness of the (V,Mo)N coatings decreased with increasing N/metal ratio, which may be related to the N-vacancy hardening effect. The sample deposited at 6 SCCM nitrogen flow rate and 3% duty cycle for 36 h showed the highest hardness of 28.4 GPa, which was possibly associated with the phase separation, and hence plastic deformation became difficult. The fracture toughness (Gc) of the (V,Mo)N coatings was evaluated using the internal energy-induced cracking method. The resultant Gc of the (V,Mo)N coatings, ranging from 36.1 to 43.7 J/m2, was higher than that of the coatings deposited by dc-UBMS in our previous study. The toughness enhancement could be caused by a higher fraction of Mo–N bonding due to the adequate reaction energy provided by the HPPMS process.","PeriodicalId":17490,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135142191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}